Google Git
Sign in
android / toolchain / rustc / 5139364148b53d79de1b5e778004d41a6a33a4a2 / . / vendor / cranelift-codegen / src / isa / x64 / lower.isle
blob: 9691cec469efd0f9fe378bdeda299cc52e228e5a [file] [log] [blame]
;; x86-64 instruction selection and CLIF-to-MachInst lowering.
;; The main lowering constructor term: takes a clif `Inst` and returns the
;; register(s) within which the lowered instruction's result values live.
(decl partial lower (Inst) InstOutput)
;; A variant of the main lowering constructor term, used for branches.
;; The only difference is that it gets an extra argument holding a vector
;; of branch targets to be used.
(decl partial lower_branch (Inst MachLabelSlice) Unit)
;;;; Rules for `iconst` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule (lower (has_type (fits_in_64 ty)
(iconst (u64_from_imm64 x))))
(imm ty x))
;; `i128`
(rule 1 (lower (has_type $I128
(iconst (u64_from_imm64 x))))
(value_regs (imm $I64 x)
(imm $I64 0)))
;;;; Rules for `f32const` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (f32const (u32_from_ieee32 x)))
(imm $F32 x))
;;;; Rules for `f64const` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (f64const (u64_from_ieee64 x)))
(imm $F64 x))
;;;; Rules for `null` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty (null)))
(imm ty 0))
;;;; Rules for `iadd` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
;; Base case for 8 and 16-bit types
(rule -6 (lower (has_type (fits_in_16 ty)
(iadd x y)))
(x64_add ty x y))
;; Base case for 32 and 64-bit types which might end up using the `lea`
;; instruction to fold multiple operations into one.
;;
;; Note that at this time this always generates a `lea` pseudo-instruction,
;; but the actual instruction emitted might be an `add` if it's equivalent.
;; For more details on this see the `emit.rs` logic to emit
;; `LoadEffectiveAddress`.
(rule -5 (lower (has_type (ty_32_or_64 ty) (iadd x y)))
(x64_lea ty (to_amode_add (mem_flags_trusted) x y (zero_offset))))
;; Higher-priority cases than the previous two where a load can be sunk into
;; the add instruction itself. Note that both operands are tested for
;; sink-ability since addition is commutative
(rule -4 (lower (has_type (fits_in_64 ty)
(iadd x (sinkable_load y))))
(x64_add ty x y))
(rule -3 (lower (has_type (fits_in_64 ty)
(iadd (sinkable_load x) y)))
(x64_add ty y x))
;; SSE.
(rule (lower (has_type (multi_lane 8 16)
(iadd x y)))
(x64_paddb x y))
(rule (lower (has_type (multi_lane 16 8)
(iadd x y)))
(x64_paddw x y))
(rule (lower (has_type (multi_lane 32 4)
(iadd x y)))
(x64_paddd x y))
(rule (lower (has_type (multi_lane 64 2)
(iadd x y)))
(x64_paddq x y))
;; `i128`
(rule 1 (lower (has_type $I128 (iadd x y)))
;; Get the high/low registers for `x`.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
;; Get the high/low registers for `y`.
(let ((y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
;; Do an add followed by an add-with-carry.
(with_flags (x64_add_with_flags_paired $I64 x_lo y_lo)
(x64_adc_paired $I64 x_hi y_hi)))))
;;;; Helpers for `*_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(decl construct_overflow_op (CC ProducesFlags) InstOutput)
(rule (construct_overflow_op cc inst)
(let ((results ValueRegs (with_flags inst
(x64_setcc_paired cc))))
(output_pair (value_regs_get results 0)
(value_regs_get results 1))))
(decl construct_overflow_op_alu (Type CC AluRmiROpcode Gpr GprMemImm) InstOutput)
(rule (construct_overflow_op_alu ty cc alu_op src1 src2)
(construct_overflow_op cc (x64_alurmi_with_flags_paired alu_op ty src1 src2)))
;; This essentially creates
;; alu_<op1> x_lo, y_lo
;; alu_<op2> x_hi, y_hi
;; set<cc> r8
(decl construct_overflow_op_alu_128 (CC AluRmiROpcode AluRmiROpcode Value Value) InstOutput)
(rule (construct_overflow_op_alu_128 cc op1 op2 x y)
;; Get the high/low registers for `x`.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
;; Get the high/low registers for `y`.
(let ((y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
(let ((lo_inst ProducesFlags (x64_alurmi_with_flags_paired op1 $I64 x_lo y_lo))
(hi_inst ConsumesAndProducesFlags (x64_alurmi_with_flags_chained op2 $I64 x_hi y_hi))
(of_inst ConsumesFlags (x64_setcc_paired cc))
(result MultiReg (with_flags_chained lo_inst hi_inst of_inst)))
(multi_reg_to_pair_and_single result)))))
;;;; Rules for `uadd_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (uadd_overflow x y @ (value_type (fits_in_64 ty))))
(construct_overflow_op_alu ty (CC.B) (AluRmiROpcode.Add) x y))
;; i128 gets lowered into adc and add
(rule 0 (lower (uadd_overflow x y @ (value_type $I128)))
(construct_overflow_op_alu_128 (CC.B) (AluRmiROpcode.Add) (AluRmiROpcode.Adc) x y))
;;;; Rules for `sadd_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (sadd_overflow x y @ (value_type (fits_in_64 ty))))
(construct_overflow_op_alu ty (CC.O) (AluRmiROpcode.Add) x y))
(rule 0 (lower (sadd_overflow x y @ (value_type $I128)))
(construct_overflow_op_alu_128 (CC.O) (AluRmiROpcode.Add) (AluRmiROpcode.Adc) x y))
;;;; Rules for `usub_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (usub_overflow x y @ (value_type (fits_in_64 ty))))
(construct_overflow_op_alu ty (CC.B) (AluRmiROpcode.Sub) x y))
(rule 0 (lower (usub_overflow x y @ (value_type $I128)))
(construct_overflow_op_alu_128 (CC.B) (AluRmiROpcode.Sub) (AluRmiROpcode.Sbb) x y))
;;;; Rules for `ssub_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (ssub_overflow x y @ (value_type (fits_in_64 ty))))
(construct_overflow_op_alu ty (CC.O) (AluRmiROpcode.Sub) x y))
(rule 0 (lower (ssub_overflow x y @ (value_type $I128)))
(construct_overflow_op_alu_128 (CC.O) (AluRmiROpcode.Sub) (AluRmiROpcode.Sbb) x y))
;;;; Rules for `umul_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower (umul_overflow x y @ (value_type (fits_in_64 ty))))
(construct_overflow_op (CC.O) (x64_umullo_with_flags_paired ty x y)))
;;;; Rules for `smul_overflow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower (smul_overflow x y @ (value_type (ty_int_ref_16_to_64 ty))))
(construct_overflow_op_alu ty (CC.O) (AluRmiROpcode.Mul) x y))
;; there is no 8bit imul with an immediate operand so we need to put it in a register or memory
(rule 1 (lower (smul_overflow x y @ (value_type $I8)))
(construct_overflow_op (CC.O) (x64_alurmi_with_flags_paired (AluRmiROpcode.Mul) $I8 x (reg_mem_to_reg_mem_imm (put_in_reg_mem y)))))
;;;; Rules for `sadd_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(sadd_sat x y)))
(x64_paddsb x y))
(rule (lower (has_type (multi_lane 16 8)
(sadd_sat x y)))
(x64_paddsw x y))
;;;; Rules for `uadd_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(uadd_sat x y)))
(x64_paddusb x y))
(rule (lower (has_type (multi_lane 16 8)
(uadd_sat x y)))
(x64_paddusw x y))
;;;; Rules for `isub` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
;; Sub two registers.
(rule -3 (lower (has_type (fits_in_64 ty)
(isub x y)))
(x64_sub ty x y))
;; SSE.
(rule (lower (has_type (multi_lane 8 16)
(isub x y)))
(x64_psubb x y))
(rule (lower (has_type (multi_lane 16 8)
(isub x y)))
(x64_psubw x y))
(rule (lower (has_type (multi_lane 32 4)
(isub x y)))
(x64_psubd x y))
(rule (lower (has_type (multi_lane 64 2)
(isub x y)))
(x64_psubq x y))
;; `i128`
(rule 1 (lower (has_type $I128 (isub x y)))
;; Get the high/low registers for `x`.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
;; Get the high/low registers for `y`.
(let ((y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
;; Do a sub followed by an sub-with-borrow.
(with_flags (x64_sub_with_flags_paired $I64 x_lo y_lo)
(x64_sbb_paired $I64 x_hi y_hi)))))
;;;; Rules for `ssub_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(ssub_sat x y)))
(x64_psubsb x y))
(rule (lower (has_type (multi_lane 16 8)
(ssub_sat x y)))
(x64_psubsw x y))
;;;; Rules for `usub_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(usub_sat x y)))
(x64_psubusb x y))
(rule (lower (has_type (multi_lane 16 8)
(usub_sat x y)))
(x64_psubusw x y))
;;;; Rules for `band` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `{i,b}64` and smaller.
;; And two registers.
(rule 0 (lower (has_type ty (band x y)))
(if (ty_int_ref_scalar_64 ty))
(x64_and ty x y))
;; The above case automatically handles when the rhs is an immediate or a
;; sinkable load, but additionally handle the lhs here.
(rule 1 (lower (has_type ty (band (sinkable_load x) y)))
(if (ty_int_ref_scalar_64 ty))
(x64_and ty y x))
(rule 2 (lower (has_type ty (band (simm32_from_value x) y)))
(if (ty_int_ref_scalar_64 ty))
(x64_and ty y x))
;; f32 and f64
(rule 5 (lower (has_type (ty_scalar_float ty) (band x y)))
(sse_and ty x y))
;; SSE.
(decl sse_and (Type Xmm XmmMem) Xmm)
(rule (sse_and $F32X4 x y) (x64_andps x y))
(rule (sse_and $F64X2 x y) (x64_andpd x y))
(rule (sse_and $F32 x y) (x64_andps x y))
(rule (sse_and $F64 x y) (x64_andpd x y))
(rule -1 (sse_and (multi_lane _bits _lanes) x y) (x64_pand x y))
(rule 6 (lower (has_type ty @ (multi_lane _bits _lanes)
(band x y)))
(sse_and ty x y))
;; `i128`.
(decl and_i128 (ValueRegs ValueRegs) ValueRegs)
(rule (and_i128 x y)
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
(value_gprs (x64_and $I64 x_lo y_lo)
(x64_and $I64 x_hi y_hi))))
(rule 7 (lower (has_type $I128 (band x y)))
(and_i128 x y))
;; Specialized lowerings for `(band x (bnot y))` which is additionally produced
;; by Cranelift's `band_not` instruction that is legalized into the simpler
;; forms early on.
(decl sse_and_not (Type Xmm XmmMem) Xmm)
(rule (sse_and_not $F32X4 x y) (x64_andnps x y))
(rule (sse_and_not $F64X2 x y) (x64_andnpd x y))
(rule -1 (sse_and_not (multi_lane _bits _lanes) x y) (x64_pandn x y))
;; Note the flipping of operands below as we're match
;;
;; (band x (bnot y))
;;
;; while x86 does
;;
;; pandn(x, y) = and(not(x), y)
(rule 8 (lower (has_type ty @ (multi_lane _bits _lane) (band x (bnot y))))
(sse_and_not ty y x))
(rule 9 (lower (has_type ty @ (multi_lane _bits _lane) (band (bnot y) x)))
(sse_and_not ty y x))
(rule 10 (lower (has_type ty (band x (bnot y))))
(if (ty_int_ref_scalar_64 ty))
(if-let $true (use_bmi1))
;; the first argument is the one that gets inverted with andn
(x64_andn ty y x))
(rule 11 (lower (has_type ty (band (bnot y) x)))
(if (ty_int_ref_scalar_64 ty))
(if-let $true (use_bmi1))
(x64_andn ty y x))
;; Specialization of `blsr` for BMI1
(decl pure partial val_minus_one (Value) Value)
(rule 0 (val_minus_one (isub x (u64_from_iconst 1))) x)
(rule 0 (val_minus_one (iadd x (i64_from_iconst -1))) x)
(rule 1 (val_minus_one (iadd (i64_from_iconst -1) x)) x)
(rule 12 (lower (has_type (ty_32_or_64 ty) (band x y)))
(if-let $true (use_bmi1))
(if-let x (val_minus_one y))
(x64_blsr ty x))
(rule 13 (lower (has_type (ty_32_or_64 ty) (band y x)))
(if-let $true (use_bmi1))
(if-let x (val_minus_one y))
(x64_blsr ty x))
;; Specialization of `blsi` for BMI1
(rule 14 (lower (has_type (ty_32_or_64 ty) (band (ineg x) x)))
(if-let $true (use_bmi1))
(x64_blsi ty x))
(rule 15 (lower (has_type (ty_32_or_64 ty) (band x (ineg x))))
(if-let $true (use_bmi1))
(x64_blsi ty x))
;; Specialization of `bzhi` for BMI2
;;
;; The `bzhi` instruction clears all bits indexed by the second operand of the
;; first operand. This is pattern-matched here with a `band` against a mask
;; which is generated to be N bits large. Note that if the index is larger than
;; the bit-width of the type then `bzhi` doesn't have the same semantics as
;; `ishl`, so an `and` instruction is required to mask the index to match the
;; semantics of Cranelift's `ishl`.
(rule 16 (lower (has_type (ty_32_or_64 ty) (band x y)))
(if-let $true (use_bmi2))
(if-let (ishl (u64_from_iconst 1) index) (val_minus_one y))
(x64_bzhi ty x (x64_and ty index (RegMemImm.Imm (u32_sub (ty_bits ty) 1)))))
;;;; Rules for `bor` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `{i,b}64` and smaller.
;; Or two registers.
(rule 0 (lower (has_type ty (bor x y)))
(if (ty_int_ref_scalar_64 ty))
(x64_or ty x y))
;; Handle immediates/sinkable loads on the lhs in addition to the automatic
;; handling of the rhs above
(rule 1 (lower (has_type ty (bor (sinkable_load x) y)))
(if (ty_int_ref_scalar_64 ty))
(x64_or ty y x))
(rule 2 (lower (has_type ty (bor (simm32_from_value x) y)))
(if (ty_int_ref_scalar_64 ty))
(x64_or ty y x))
;; f32 and f64
(rule 5 (lower (has_type (ty_scalar_float ty) (bor x y)))
(sse_or ty x y))
;; SSE.
(decl sse_or (Type Xmm XmmMem) Xmm)
(rule (sse_or $F32X4 x y) (x64_orps x y))
(rule (sse_or $F64X2 x y) (x64_orpd x y))
(rule (sse_or $F32 x y) (x64_orps x y))
(rule (sse_or $F64 x y) (x64_orpd x y))
(rule -1 (sse_or (multi_lane _bits _lanes) x y) (x64_por x y))
(rule 6 (lower (has_type ty @ (multi_lane _bits _lanes)
(bor x y)))
(sse_or ty x y))
;; `{i,b}128`.
(decl or_i128 (ValueRegs ValueRegs) ValueRegs)
(rule (or_i128 x y)
(let ((x_lo Gpr (value_regs_get_gpr x 0))
(x_hi Gpr (value_regs_get_gpr x 1))
(y_lo Gpr (value_regs_get_gpr y 0))
(y_hi Gpr (value_regs_get_gpr y 1)))
(value_gprs (x64_or $I64 x_lo y_lo)
(x64_or $I64 x_hi y_hi))))
(rule 7 (lower (has_type $I128 (bor x y)))
(or_i128 x y))
;;;; Rules for `bxor` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `{i,b}64` and smaller.
;; Xor two registers.
(rule 0 (lower (has_type ty (bxor x y)))
(if (ty_int_ref_scalar_64 ty))
(x64_xor ty x y))
;; Handle xor with lhs immediates/sinkable loads in addition to the automatic
;; handling of the rhs above.
(rule 1 (lower (has_type ty (bxor (sinkable_load x) y)))
(if (ty_int_ref_scalar_64 ty))
(x64_xor ty y x))
(rule 4 (lower (has_type ty (bxor (simm32_from_value x) y)))
(if (ty_int_ref_scalar_64 ty))
(x64_xor ty y x))
;; f32 and f64
(rule 5 (lower (has_type (ty_scalar_float ty) (bxor x y)))
(x64_xor_vector ty x y))
;; SSE.
(rule 6 (lower (has_type ty @ (multi_lane _bits _lanes) (bxor x y)))
(x64_xor_vector ty x y))
;; `{i,b}128`.
(rule 7 (lower (has_type $I128 (bxor x y)))
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
(y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1)))
(value_gprs (x64_xor $I64 x_lo y_lo)
(x64_xor $I64 x_hi y_hi))))
;; Specialization of `blsmsk` for BMI1
(rule 8 (lower (has_type (ty_32_or_64 ty) (bxor x y)))
(if-let $true (use_bmi1))
(if-let x (val_minus_one y))
(x64_blsmsk ty x))
(rule 9 (lower (has_type (ty_32_or_64 ty) (bxor y x)))
(if-let $true (use_bmi1))
(if-let x (val_minus_one y))
(x64_blsmsk ty x))
;;;; Rules for `ishl` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (ishl src amt)))
(x64_shl ty src (put_masked_in_imm8_gpr amt ty)))
;; `i128`.
(decl shl_i128 (ValueRegs Gpr) ValueRegs)
(rule (shl_i128 src amt)
;; Unpack the registers that make up the 128-bit value being shifted.
(let ((src_lo Gpr (value_regs_get_gpr src 0))
(src_hi Gpr (value_regs_get_gpr src 1))
;; Do two 64-bit shifts.
(lo_shifted Gpr (x64_shl $I64 src_lo amt))
(hi_shifted Gpr (x64_shl $I64 src_hi amt))
;; `src_lo >> (64 - amt)` are the bits to carry over from the lo
;; into the hi.
(carry Gpr (x64_shr $I64
src_lo
(x64_sub $I64
(imm $I64 64)
amt)))
(zero Gpr (imm $I64 0))
;; Nullify the carry if we are shifting in by a multiple of 128.
(carry_ Gpr (with_flags_reg (x64_test (OperandSize.Size64)
(RegMemImm.Imm 127)
amt)
(cmove $I64
(CC.Z)
zero
carry)))
;; Add the carry into the high half.
(hi_shifted_ Gpr (x64_or $I64 carry_ hi_shifted)))
;; Combine the two shifted halves. However, if we are shifting by >= 64
;; (modulo 128), then the low bits are zero and the high bits are our
;; low bits.
(with_flags (x64_test (OperandSize.Size64) (RegMemImm.Imm 64) amt)
(consumes_flags_concat
(cmove $I64 (CC.Z) lo_shifted zero)
(cmove $I64 (CC.Z) hi_shifted_ lo_shifted)))))
(rule (lower (has_type $I128 (ishl src amt)))
;; NB: Only the low bits of `amt` matter since we logically mask the shift
;; amount to the value's bit width.
(let ((amt_ Gpr (lo_gpr amt)))
(shl_i128 src amt_)))
;; SSE.
;; Since the x86 instruction set does not have any 8x16 shift instructions (even
;; in higher feature sets like AVX), we lower the `ishl.i8x16` to a sequence of
;; instructions. The basic idea, whether the amount to shift by is an immediate
;; or not, is to use a 16x8 shift and then mask off the incorrect bits to 0s.
(rule (lower (has_type ty @ $I8X16 (ishl src amt)))
(let (
;; Mask the amount to ensure wrapping behaviour
(masked_amt RegMemImm (mask_xmm_shift ty amt))
;; Shift `src` using 16x8. Unfortunately, a 16x8 shift will only be
;; correct for half of the lanes; the others must be fixed up with
;; the mask below.
(unmasked Xmm (x64_psllw src (mov_rmi_to_xmm masked_amt)))
(mask_addr SyntheticAmode (ishl_i8x16_mask masked_amt))
(mask Reg (x64_load $I8X16 mask_addr (ExtKind.None))))
(sse_and $I8X16 unmasked (RegMem.Reg mask))))
;; Get the address of the mask to use when fixing up the lanes that weren't
;; correctly generated by the 16x8 shift.
(decl ishl_i8x16_mask (RegMemImm) SyntheticAmode)
;; When the shift amount is known, we can statically (i.e. at compile time)
;; determine the mask to use and only emit that.
(decl ishl_i8x16_mask_for_const (u32) SyntheticAmode)
(extern constructor ishl_i8x16_mask_for_const ishl_i8x16_mask_for_const)
(rule (ishl_i8x16_mask (RegMemImm.Imm amt))
(ishl_i8x16_mask_for_const amt))
;; Otherwise, we must emit the entire mask table and dynamically (i.e. at run
;; time) find the correct mask offset in the table. We use `lea` to find the
;; base address of the mask table and then complex addressing to offset to the
;; right mask: `base_address + amt << 4`
(decl ishl_i8x16_mask_table () SyntheticAmode)
(extern constructor ishl_i8x16_mask_table ishl_i8x16_mask_table)
(rule (ishl_i8x16_mask (RegMemImm.Reg amt))
(let ((mask_table SyntheticAmode (ishl_i8x16_mask_table))
(base_mask_addr Gpr (x64_lea $I64 mask_table))
(mask_offset Gpr (x64_shl $I64 amt
(imm8_to_imm8_gpr 4))))
(Amode.ImmRegRegShift 0
base_mask_addr
mask_offset
0
(mem_flags_trusted))))
(rule (ishl_i8x16_mask (RegMemImm.Mem amt))
(ishl_i8x16_mask (RegMemImm.Reg (x64_load $I64 amt (ExtKind.None)))))
;; 16x8, 32x4, and 64x2 shifts can each use a single instruction, once the shift amount is masked.
(rule (lower (has_type ty @ $I16X8 (ishl src amt)))
(x64_psllw src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
(rule (lower (has_type ty @ $I32X4 (ishl src amt)))
(x64_pslld src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
(rule (lower (has_type ty @ $I64X2 (ishl src amt)))
(x64_psllq src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
;;;; Rules for `ushr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (ushr src amt)))
(let ((src_ Gpr (extend_to_gpr src ty (ExtendKind.Zero))))
(x64_shr ty src_ (put_masked_in_imm8_gpr amt ty))))
;; `i128`.
(decl shr_i128 (ValueRegs Gpr) ValueRegs)
(rule (shr_i128 src amt)
;; Unpack the lo/hi halves of `src`.
(let ((src_lo Gpr (value_regs_get_gpr src 0))
(src_hi Gpr (value_regs_get_gpr src 1))
;; Do a shift on each half.
(lo_shifted Gpr (x64_shr $I64 src_lo amt))
(hi_shifted Gpr (x64_shr $I64 src_hi amt))
;; `src_hi << (64 - amt)` are the bits to carry over from the hi
;; into the lo.
(carry Gpr (x64_shl $I64
src_hi
(x64_sub $I64
(imm $I64 64)
amt)))
;; Share the zero value to reduce register pressure
(zero Gpr (imm $I64 0))
;; Nullify the carry if we are shifting by a multiple of 128.
(carry_ Gpr (with_flags_reg (x64_test (OperandSize.Size64) (RegMemImm.Imm 127) amt)
(cmove $I64 (CC.Z) zero carry)))
;; Add the carry bits into the lo.
(lo_shifted_ Gpr (x64_or $I64 carry_ lo_shifted)))
;; Combine the two shifted halves. However, if we are shifting by >= 64
;; (modulo 128), then the hi bits are zero and the lo bits are what
;; would otherwise be our hi bits.
(with_flags (x64_test (OperandSize.Size64) (RegMemImm.Imm 64) amt)
(consumes_flags_concat
(cmove $I64 (CC.Z) lo_shifted_ hi_shifted)
(cmove $I64 (CC.Z) hi_shifted zero)))))
(rule (lower (has_type $I128 (ushr src amt)))
;; NB: Only the low bits of `amt` matter since we logically mask the shift
;; amount to the value's bit width.
(let ((amt_ Gpr (lo_gpr amt)))
(shr_i128 src amt_)))
;; SSE.
;; There are no 8x16 shifts in x64. Do the same 16x8-shift-and-mask thing we do
;; with 8x16 `ishl`.
(rule (lower (has_type ty @ $I8X16 (ushr src amt)))
(let (
;; Mask the amount to ensure wrapping behaviour
(masked_amt RegMemImm (mask_xmm_shift ty amt))
;; Shift `src` using 16x8. Unfortunately, a 16x8 shift will only be
;; correct for half of the lanes; the others must be fixed up with
;; the mask below.
(unmasked Xmm (x64_psrlw src (mov_rmi_to_xmm masked_amt))))
(sse_and $I8X16
unmasked
(ushr_i8x16_mask masked_amt))))
;; Get the address of the mask to use when fixing up the lanes that weren't
;; correctly generated by the 16x8 shift.
(decl ushr_i8x16_mask (RegMemImm) SyntheticAmode)
;; When the shift amount is known, we can statically (i.e. at compile time)
;; determine the mask to use and only emit that.
(decl ushr_i8x16_mask_for_const (u32) SyntheticAmode)
(extern constructor ushr_i8x16_mask_for_const ushr_i8x16_mask_for_const)
(rule (ushr_i8x16_mask (RegMemImm.Imm amt))
(ushr_i8x16_mask_for_const amt))
;; Otherwise, we must emit the entire mask table and dynamically (i.e. at run
;; time) find the correct mask offset in the table. We use `lea` to find the
;; base address of the mask table and then complex addressing to offset to the
;; right mask: `base_address + amt << 4`
(decl ushr_i8x16_mask_table () SyntheticAmode)
(extern constructor ushr_i8x16_mask_table ushr_i8x16_mask_table)
(rule (ushr_i8x16_mask (RegMemImm.Reg amt))
(let ((mask_table SyntheticAmode (ushr_i8x16_mask_table))
(base_mask_addr Gpr (x64_lea $I64 mask_table))
(mask_offset Gpr (x64_shl $I64
amt
(imm8_to_imm8_gpr 4))))
(Amode.ImmRegRegShift 0
base_mask_addr
mask_offset
0
(mem_flags_trusted))))
(rule (ushr_i8x16_mask (RegMemImm.Mem amt))
(ushr_i8x16_mask (RegMemImm.Reg (x64_load $I64 amt (ExtKind.None)))))
;; 16x8, 32x4, and 64x2 shifts can each use a single instruction, once the shift amount is masked.
(rule (lower (has_type ty @ $I16X8 (ushr src amt)))
(x64_psrlw src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
(rule (lower (has_type ty @ $I32X4 (ushr src amt)))
(x64_psrld src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
(rule (lower (has_type ty @ $I64X2 (ushr src amt)))
(x64_psrlq src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
(decl mask_xmm_shift (Type Value) RegMemImm)
(rule (mask_xmm_shift ty amt)
(gpr_to_reg (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(rule 1 (mask_xmm_shift ty (iconst n))
(RegMemImm.Imm (shift_amount_masked ty n)))
;;;; Rules for `sshr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (sshr src amt)))
(let ((src_ Gpr (extend_to_gpr src ty (ExtendKind.Sign))))
(x64_sar ty src_ (put_masked_in_imm8_gpr amt ty))))
;; `i128`.
(decl sar_i128 (ValueRegs Gpr) ValueRegs)
(rule (sar_i128 src amt)
;; Unpack the low/high halves of `src`.
(let ((src_lo Gpr (value_regs_get_gpr src 0))
(src_hi Gpr (value_regs_get_gpr src 1))
;; Do a shift of each half. NB: the low half uses an unsigned shift
;; because its MSB is not a sign bit.
(lo_shifted Gpr (x64_shr $I64 src_lo amt))
(hi_shifted Gpr (x64_sar $I64 src_hi amt))
;; `src_hi << (64 - amt)` are the bits to carry over from the low
;; half to the high half.
(carry Gpr (x64_shl $I64
src_hi
(x64_sub $I64
(imm $I64 64)
amt)))
;; Nullify the carry if we are shifting by a multiple of 128.
(carry_ Gpr (with_flags_reg (x64_test (OperandSize.Size64) (RegMemImm.Imm 127) amt)
(cmove $I64 (CC.Z) (imm $I64 0) carry)))
;; Add the carry into the low half.
(lo_shifted_ Gpr (x64_or $I64 lo_shifted carry_))
;; Get all sign bits.
(sign_bits Gpr (x64_sar $I64 src_hi (imm8_to_imm8_gpr 63))))
;; Combine the two shifted halves. However, if we are shifting by >= 64
;; (modulo 128), then the hi bits are all sign bits and the lo bits are
;; what would otherwise be our hi bits.
(with_flags (x64_test (OperandSize.Size64) (RegMemImm.Imm 64) amt)
(consumes_flags_concat
(cmove $I64 (CC.Z) lo_shifted_ hi_shifted)
(cmove $I64 (CC.Z) hi_shifted sign_bits)))))
(rule (lower (has_type $I128 (sshr src amt)))
;; NB: Only the low bits of `amt` matter since we logically mask the shift
;; amount to the value's bit width.
(let ((amt_ Gpr (lo_gpr amt)))
(sar_i128 src amt_)))
;; SSE.
;; Since the x86 instruction set does not have an 8x16 shift instruction and the
;; approach used for `ishl` and `ushr` cannot be easily used (the masks do not
;; preserve the sign), we use a different approach here: separate the low and
;; high lanes, shift them separately, and merge them into the final result.
;;
;; Visually, this looks like the following, where `src.i8x16 = [s0, s1, ...,
;; s15]:
;;
;; lo.i16x8 = [(s0, s0), (s1, s1), ..., (s7, s7)]
;; shifted_lo.i16x8 = shift each lane of `low`
;; hi.i16x8 = [(s8, s8), (s9, s9), ..., (s15, s15)]
;; shifted_hi.i16x8 = shift each lane of `high`
;; result = [s0'', s1'', ..., s15'']
(rule (lower (has_type ty @ $I8X16 (sshr src amt @ (value_type amt_ty))))
(let ((src_ Xmm (put_in_xmm src))
;; Mask the amount to ensure wrapping behaviour
(masked_amt RegMemImm (mask_xmm_shift ty amt))
;; In order for `packsswb` later to only use the high byte of each
;; 16x8 lane, we shift right an extra 8 bits, relying on `psraw` to
;; fill in the upper bits appropriately.
(lo Xmm (x64_punpcklbw src_ src_))
(hi Xmm (x64_punpckhbw src_ src_))
(amt_ XmmMemImm (sshr_i8x16_bigger_shift amt_ty masked_amt))
(shifted_lo Xmm (x64_psraw lo amt_))
(shifted_hi Xmm (x64_psraw hi amt_)))
(x64_packsswb shifted_lo shifted_hi)))
(decl sshr_i8x16_bigger_shift (Type RegMemImm) XmmMemImm)
(rule (sshr_i8x16_bigger_shift _ty (RegMemImm.Imm i))
(xmm_mem_imm_new (RegMemImm.Imm (u32_add i 8))))
(rule (sshr_i8x16_bigger_shift ty (RegMemImm.Reg r))
(mov_rmi_to_xmm (RegMemImm.Reg (x64_add ty
r
(RegMemImm.Imm 8)))))
(rule (sshr_i8x16_bigger_shift ty rmi @ (RegMemImm.Mem _m))
(mov_rmi_to_xmm (RegMemImm.Reg (x64_add ty
(imm ty 8)
rmi))))
;; `sshr.{i16x8,i32x4}` can be a simple `psra{w,d}`, we just have to make sure
;; that if the shift amount is in a register, it is in an XMM register.
(rule (lower (has_type ty @ $I16X8 (sshr src amt)))
(x64_psraw src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
(rule (lower (has_type ty @ $I32X4 (sshr src amt)))
(x64_psrad src (mov_rmi_to_xmm (mask_xmm_shift ty amt))))
;; The `sshr.i64x2` CLIF instruction has no single x86 instruction in the older
;; feature sets. To remedy this, a small dance is done with an unsigned right
;; shift plus some extra ops.
(rule 3 (lower (has_type ty @ $I64X2 (sshr src (iconst n))))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512f))
(x64_vpsraq_imm src (shift_amount_masked ty n)))
(rule 2 (lower (has_type ty @ $I64X2 (sshr src amt)))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512f))
(let ((masked Gpr (x64_and $I64 amt (RegMemImm.Imm (shift_mask ty)))))
(x64_vpsraq src (x64_movd_to_xmm masked))))
(rule 1 (lower (has_type $I64X2 (sshr src (iconst (u64_from_imm64 (u64_as_u32 amt))))))
(lower_i64x2_sshr_imm src (u32_and amt 63)))
(rule (lower (has_type $I64X2 (sshr src amt)))
(lower_i64x2_sshr_gpr src (x64_and $I64 amt (RegMemImm.Imm 63))))
(decl lower_i64x2_sshr_imm (Xmm u32) Xmm)
;; If the shift amount is less than 32 then do an sshr with 32-bit lanes to
;; produce the upper halves of each result, followed by a ushr of 64-bit lanes
;; to produce the lower halves of each result. Interleave results at the end.
(rule 2 (lower_i64x2_sshr_imm vec imm)
(if-let $true (u64_lt imm 32))
(let (
(high32 Xmm (x64_psrad vec (xmi_imm imm)))
(high32 Xmm (x64_pshufd high32 0b11_10_11_01))
(low32 Xmm (x64_psrlq vec (xmi_imm imm)))
(low32 Xmm (x64_pshufd low32 0b11_10_10_00))
)
(x64_punpckldq low32 high32)))
;; If the shift amount is 32 then the `psrlq` from the above rule can be avoided
(rule 1 (lower_i64x2_sshr_imm vec 32)
(let (
(low32 Xmm (x64_pshufd vec 0b11_10_11_01))
(high32 Xmm (x64_psrad vec (xmi_imm 31)))
(high32 Xmm (x64_pshufd high32 0b11_10_11_01))
)
(x64_punpckldq low32 high32)))
;; Shifts >= 32 use one `psrad` to generate the upper bits and second `psrad` to
;; generate the lower bits. Everything is then woven back together with
;; shuffles.
(rule (lower_i64x2_sshr_imm vec imm)
(if-let $true (u64_lt 32 imm))
(let (
(high32 Xmm (x64_psrad vec (xmi_imm 31)))
(high32 Xmm (x64_pshufd high32 0b11_10_11_01))
(low32 Xmm (x64_psrad vec (xmi_imm (u32_sub imm 32))))
(low32 Xmm (x64_pshufd low32 0b11_10_11_01))
)
(x64_punpckldq low32 high32)))
;; A variable shift amount is slightly more complicated than the immediate
;; shift amounts from above. The `Gpr` argument is guaranteed to be <= 63 by
;; earlier masking. A `ushr` operation is used with some xor/sub math to
;; generate the sign bits.
(decl lower_i64x2_sshr_gpr (Xmm Gpr) Xmm)
(rule (lower_i64x2_sshr_gpr vec val)
(let (
(val Xmm (x64_movq_to_xmm val))
(mask Xmm (flip_high_bit_mask $I64X2))
(sign_bit_loc Xmm (x64_psrlq mask val))
(ushr Xmm (x64_psrlq vec val))
(ushr_sign_bit_flip Xmm (x64_pxor sign_bit_loc ushr))
)
(x64_psubq ushr_sign_bit_flip sign_bit_loc)))
;;;; Rules for `rotl` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller: we can rely on x86's rotate-amount masking since
;; we operate on the whole register. For const's we mask the constant.
(rule -1 (lower (has_type (fits_in_64 ty) (rotl src amt)))
(x64_rotl ty src (put_masked_in_imm8_gpr amt ty)))
;; `i128`.
(rule (lower (has_type $I128 (rotl src amt)))
(let ((src_ ValueRegs src)
;; NB: Only the low bits of `amt` matter since we logically mask the
;; rotation amount to the value's bit width.
(amt_ Gpr (lo_gpr amt)))
(or_i128 (shl_i128 src_ amt_)
(shr_i128 src_ (x64_sub $I64
(imm $I64 128)
amt_)))))
;;;; Rules for `rotr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller: we can rely on x86's rotate-amount masking since
;; we operate on the whole register. For const's we mask the constant.
(rule -1 (lower (has_type (fits_in_64 ty) (rotr src amt)))
(x64_rotr ty src (put_masked_in_imm8_gpr amt ty)))
;; `i128`.
(rule (lower (has_type $I128 (rotr src amt)))
(let ((src_ ValueRegs src)
;; NB: Only the low bits of `amt` matter since we logically mask the
;; rotation amount to the value's bit width.
(amt_ Gpr (lo_gpr amt)))
(or_i128 (shr_i128 src_ amt_)
(shl_i128 src_ (x64_sub $I64
(imm $I64 128)
amt_)))))
;;;; Rules for `ineg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (ineg x)))
(x64_neg ty x))
(rule -2 (lower (has_type $I128 (ineg x)))
;; Get the high/low registers for `x`.
(let ((regs ValueRegs x)
(lo Gpr (value_regs_get_gpr regs 0))
(hi Gpr (value_regs_get_gpr regs 1)))
;; Do a neg followed by an sub-with-borrow.
(with_flags (x64_neg_paired $I64 lo)
(x64_sbb_paired $I64 (imm $I64 0) hi))))
;; SSE.
(rule (lower (has_type $I8X16 (ineg x)))
(x64_psubb (imm $I8X16 0) x))
(rule (lower (has_type $I16X8 (ineg x)))
(x64_psubw (imm $I16X8 0) x))
(rule (lower (has_type $I32X4 (ineg x)))
(x64_psubd (imm $I32X4 0) x))
(rule (lower (has_type $I64X2 (ineg x)))
(x64_psubq (imm $I64X2 0) x))
;;;; Rules for `avg_round` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (multi_lane 8 16)
(avg_round x y)))
(x64_pavgb x y))
(rule (lower (has_type (multi_lane 16 8)
(avg_round x y)))
(x64_pavgw x y))
;;;; Rules for `imul` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
;; Multiply two registers.
(rule -5 (lower (has_type (fits_in_64 ty) (imul x y)))
(x64_mul ty x y))
;; Handle multiplication where the lhs is an immediate or sinkable load in
;; addition to the automatic rhs handling above.
(rule -4 (lower (has_type (fits_in_64 ty)
(imul (simm32_from_value x) y)))
(x64_mul ty y x))
(rule -3 (lower (has_type (fits_in_64 ty)
(imul (sinkable_load x) y)))
(x64_mul ty y x))
;; `i128`.
;; mul:
;; dst_lo = lhs_lo * rhs_lo
;; dst_hi = umulhi(lhs_lo, rhs_lo) +
;; lhs_lo * rhs_hi +
;; lhs_hi * rhs_lo
;;
;; so we emit:
;; lo_hi = mul x_lo, y_hi
;; hi_lo = mul x_hi, y_lo
;; hilo_hilo = add lo_hi, hi_lo
;; dst_lo:hi_lolo = mulhi_u x_lo, y_lo
;; dst_hi = add hilo_hilo, hi_lolo
;; return (dst_lo, dst_hi)
(rule 2 (lower (has_type $I128 (imul x y)))
;; Put `x` into registers and unpack its hi/lo halves.
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1))
;; Put `y` into registers and unpack its hi/lo halves.
(y_regs ValueRegs y)
(y_lo Gpr (value_regs_get_gpr y_regs 0))
(y_hi Gpr (value_regs_get_gpr y_regs 1))
;; lo_hi = mul x_lo, y_hi
(lo_hi Gpr (x64_mul $I64 x_lo y_hi))
;; hi_lo = mul x_hi, y_lo
(hi_lo Gpr (x64_mul $I64 x_hi y_lo))
;; hilo_hilo = add lo_hi, hi_lo
(hilo_hilo Gpr (x64_add $I64 lo_hi hi_lo))
;; dst_lo:hi_lolo = mulhi_u x_lo, y_lo
(mul_regs ValueRegs (mulhi_u $I64 x_lo y_lo))
(dst_lo Gpr (value_regs_get_gpr mul_regs 0))
(hi_lolo Gpr (value_regs_get_gpr mul_regs 1))
;; dst_hi = add hilo_hilo, hi_lolo
(dst_hi Gpr (x64_add $I64 hilo_hilo hi_lolo)))
(value_gprs dst_lo dst_hi)))
;; SSE.
;; (No i8x16 multiply.)
(rule (lower (has_type (multi_lane 16 8) (imul x y)))
(x64_pmullw x y))
(rule (lower (has_type (multi_lane 32 4) (imul x y)))
(if-let $true (use_sse41))
(x64_pmulld x y))
;; Without `pmulld` the `pmuludq` instruction is used instead which performs
;; 32-bit multiplication storing the 64-bit result. The 64-bit result is
;; truncated to 32-bits and everything else is woven into place.
(rule -1 (lower (has_type (multi_lane 32 4) (imul x y)))
(let (
(x Xmm x)
(y Xmm y)
(x_hi Xmm (x64_pshufd x 0b00_11_00_01))
(y_hi Xmm (x64_pshufd y 0b00_11_00_01))
(mul_lo Xmm (x64_pshufd (x64_pmuludq x y) 0b00_00_10_00))
(mul_hi Xmm (x64_pshufd (x64_pmuludq x_hi y_hi) 0b00_00_10_00))
)
(x64_punpckldq mul_lo mul_hi)))
;; With AVX-512 we can implement `i64x2` multiplication with a single
;; instruction.
(rule 3 (lower (has_type (multi_lane 64 2) (imul x y)))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512dq))
(x64_vpmullq x y))
;; Otherwise, for i64x2 multiplication we describe a lane A as being composed of
;; a 32-bit upper half "Ah" and a 32-bit lower half "Al". The 32-bit long hand
;; multiplication can then be written as:
;;
;; Ah Al
;; * Bh Bl
;; -----
;; Al * Bl
;; + (Ah * Bl) << 32
;; + (Al * Bh) << 32
;;
;; So for each lane we will compute:
;;
;; A * B = (Al * Bl) + ((Ah * Bl) + (Al * Bh)) << 32
;;
;; Note, the algorithm will use `pmuludq` which operates directly on the lower
;; 32-bit (`Al` or `Bl`) of a lane and writes the result to the full 64-bits of
;; the lane of the destination. For this reason we don't need shifts to isolate
;; the lower 32-bits, however, we will need to use shifts to isolate the high
;; 32-bits when doing calculations, i.e., `Ah == A >> 32`.
(rule (lower (has_type (multi_lane 64 2)
(imul a b)))
(let ((a0 Xmm a)
(b0 Xmm b)
;; a_hi = A >> 32
(a_hi Xmm (x64_psrlq a0 (xmi_imm 32)))
;; ah_bl = Ah * Bl
(ah_bl Xmm (x64_pmuludq a_hi b0))
;; b_hi = B >> 32
(b_hi Xmm (x64_psrlq b0 (xmi_imm 32)))
;; al_bh = Al * Bh
(al_bh Xmm (x64_pmuludq a0 b_hi))
;; aa_bb = ah_bl + al_bh
(aa_bb Xmm (x64_paddq ah_bl al_bh))
;; aa_bb_shifted = aa_bb << 32
(aa_bb_shifted Xmm (x64_psllq aa_bb (xmi_imm 32)))
;; al_bl = Al * Bl
(al_bl Xmm (x64_pmuludq a0 b0)))
;; al_bl + aa_bb_shifted
(x64_paddq al_bl aa_bb_shifted)))
;; Special case for `i32x4.extmul_high_i16x8_s`.
(rule 1 (lower (has_type (multi_lane 32 4)
(imul (swiden_high (and (value_type (multi_lane 16 8))
x))
(swiden_high (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhw x2 y2)))
(x64_punpckhwd lo hi)))
;; Special case for `i64x2.extmul_high_i32x4_s`.
(rule 1 (lower (has_type (multi_lane 64 2)
(imul (swiden_high (and (value_type (multi_lane 32 4))
x))
(swiden_high (and (value_type (multi_lane 32 4))
y)))))
(if-let $true (use_sse41))
(let ((x2 Xmm (x64_pshufd x 0xFA))
(y2 Xmm (x64_pshufd y 0xFA)))
(x64_pmuldq x2 y2)))
;; Special case for `i32x4.extmul_low_i16x8_s`.
(rule 1 (lower (has_type (multi_lane 32 4)
(imul (swiden_low (and (value_type (multi_lane 16 8))
x))
(swiden_low (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhw x2 y2)))
(x64_punpcklwd lo hi)))
;; Special case for `i64x2.extmul_low_i32x4_s`.
(rule 1 (lower (has_type (multi_lane 64 2)
(imul (swiden_low (and (value_type (multi_lane 32 4))
x))
(swiden_low (and (value_type (multi_lane 32 4))
y)))))
(if-let $true (use_sse41))
(let ((x2 Xmm (x64_pshufd x 0x50))
(y2 Xmm (x64_pshufd y 0x50)))
(x64_pmuldq x2 y2)))
;; Special case for `i32x4.extmul_high_i16x8_u`.
(rule 1 (lower (has_type (multi_lane 32 4)
(imul (uwiden_high (and (value_type (multi_lane 16 8))
x))
(uwiden_high (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhuw x2 y2)))
(x64_punpckhwd lo hi)))
;; Special case for `i64x2.extmul_high_i32x4_u`.
(rule 1 (lower (has_type (multi_lane 64 2)
(imul (uwiden_high (and (value_type (multi_lane 32 4))
x))
(uwiden_high (and (value_type (multi_lane 32 4))
y)))))
(let ((x2 Xmm (x64_pshufd x 0xFA))
(y2 Xmm (x64_pshufd y 0xFA)))
(x64_pmuludq x2 y2)))
;; Special case for `i32x4.extmul_low_i16x8_u`.
(rule 1 (lower (has_type (multi_lane 32 4)
(imul (uwiden_low (and (value_type (multi_lane 16 8))
x))
(uwiden_low (and (value_type (multi_lane 16 8))
y)))))
(let ((x2 Xmm x)
(y2 Xmm y)
(lo Xmm (x64_pmullw x2 y2))
(hi Xmm (x64_pmulhuw x2 y2)))
(x64_punpcklwd lo hi)))
;; Special case for `i64x2.extmul_low_i32x4_u`.
(rule 1 (lower (has_type (multi_lane 64 2)
(imul (uwiden_low (and (value_type (multi_lane 32 4))
x))
(uwiden_low (and (value_type (multi_lane 32 4))
y)))))
(let ((x2 Xmm (x64_pshufd x 0x50))
(y2 Xmm (x64_pshufd y 0x50)))
(x64_pmuludq x2 y2)))
;;;; Rules for `iabs` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (has_type $I8X16 (iabs x)))
(if-let $true (use_ssse3))
(x64_pabsb x))
;; Note the use of `pminub` with signed inputs will produce the positive signed
;; result which is what is desired here. The `pmaxub` isn't available until
;; SSE4.1 in which case the single-instruction above lowering would apply.
(rule (lower (has_type $I8X16 (iabs x)))
(let (
(x Xmm x)
(negated Xmm (x64_psubb (xmm_zero $I8X16) x))
)
(x64_pminub x negated)))
(rule 1 (lower (has_type $I16X8 (iabs x)))
(if-let $true (use_ssse3))
(x64_pabsw x))
(rule (lower (has_type $I16X8 (iabs x)))
(let (
(x Xmm x)
(negated Xmm (x64_psubw (xmm_zero $I16X8) x))
)
(x64_pmaxsw x negated)))
(rule 1 (lower (has_type $I32X4 (iabs x)))
(if-let $true (use_ssse3))
(x64_pabsd x))
;; Generate a `negative_mask` which is either numerically -1 or 0 depending on
;; if the lane is negative. If the lane is positive then the xor operation
;; won't change the lane but otherwise it'll bit-flip everything. By then
;; subtracting the mask this subtracts 0 for positive lanes (does nothing) or
;; ends up adding one for negative lanes. This means that for a negative lane
;; `x` the result is `!x + 1` which is the result of negating it.
(rule (lower (has_type $I32X4 (iabs x)))
(let (
(x Xmm x)
(negative_mask Xmm (x64_psrad x (xmi_imm 31)))
(flipped_if_negative Xmm (x64_pxor x negative_mask))
)
(x64_psubd flipped_if_negative negative_mask)))
;; When AVX512 is available, we can use a single `vpabsq` instruction.
(rule 2 (lower (has_type $I64X2 (iabs x)))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512f))
(x64_vpabsq x))
;; Otherwise, we use a separate register, `neg`, to contain the results of `0 -
;; x` and then blend in those results with `blendvpd` if the MSB of `neg` was
;; set to 1 (i.e. if `neg` was negative or, conversely, if `x` was originally
;; positive).
(rule 1 (lower (has_type $I64X2 (iabs x)))
(if-let $true (use_sse41))
(let ((rx Xmm x)
(neg Xmm (x64_psubq (imm $I64X2 0) rx)))
(x64_blendvpd neg rx neg)))
;; and if `blendvpd` isn't available then perform a shift/shuffle to generate a
;; mask of which lanes are negative, followed by flipping bits/sub to make both
;; positive.
(rule (lower (has_type $I64X2 (iabs x)))
(let ((x Xmm x)
(signs Xmm (x64_psrad x (RegMemImm.Imm 31)))
(signs Xmm (x64_pshufd signs 0b11_11_01_01))
(xor_if_negative Xmm (x64_pxor x signs)))
(x64_psubq xor_if_negative signs)))
;; `i64` and smaller.
(rule -1 (lower (has_type (fits_in_64 ty) (iabs x)))
(let ((src Gpr x)
(neg ProducesFlags (x64_neg_paired ty src))
;; Manually extract the result from the neg, then ignore
;; it below, since we need to pass it into the cmove
;; before we pass the cmove to with_flags_reg.
(neg_result Gpr (produces_flags_get_reg neg))
;; When the neg instruction sets the sign flag,
;; takes the original (non-negative) value.
(cmove ConsumesFlags (cmove ty (CC.S) src neg_result)))
(with_flags_reg (produces_flags_ignore neg) cmove)))
;;;; Rules for `fabs` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fabs x)))
(x64_andps x (imm $F32 0x7fffffff)))
(rule (lower (has_type $F64 (fabs x)))
(x64_andpd x (imm $F64 0x7fffffffffffffff)))
;; Special case for `f32x4.abs`.
(rule (lower (has_type $F32X4 (fabs x)))
(x64_andps x
(x64_psrld (vector_all_ones) (xmi_imm 1))))
;; Special case for `f64x2.abs`.
(rule (lower (has_type $F64X2 (fabs x)))
(x64_andpd x
(x64_psrlq (vector_all_ones) (xmi_imm 1))))
;;;; Rules for `fneg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fneg x)))
(x64_xorps x (imm $F32 0x80000000)))
(rule (lower (has_type $F64 (fneg x)))
(x64_xorpd x (imm $F64 0x8000000000000000)))
(rule (lower (has_type $F32X4 (fneg x)))
(x64_xorps x
(x64_pslld (vector_all_ones) (xmi_imm 31))))
(rule (lower (has_type $F64X2 (fneg x)))
(x64_xorpd x
(x64_psllq (vector_all_ones) (xmi_imm 63))))
;;;; Rules for `bmask` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(decl lower_bmask (Type Type ValueRegs) ValueRegs)
;; Values that fit in a register
;;
;; Use the neg instruction on the input which sets the CF (carry) flag
;; to 0 if the input is 0 or 1 otherwise.
;; We then subtract the output register with itself, which always gives a 0,
;; however use the carry flag from the previous negate to generate a -1 if it
;; was nonzero.
;;
;; neg in_reg
;; sbb out_reg, out_reg
(rule 0
(lower_bmask (fits_in_64 out_ty) (fits_in_64 in_ty) val)
(let ((reg Gpr (value_regs_get_gpr val 0))
(out ValueRegs (with_flags
(x64_neg_paired in_ty reg)
(x64_sbb_paired out_ty reg reg))))
;; Extract only the output of the sbb instruction
(value_reg (value_regs_get out 1))))
;; If the input type is I128 we can `or` the registers, and recurse to the general case.
(rule 1
(lower_bmask (fits_in_64 out_ty) $I128 val)
(let ((lo Gpr (value_regs_get_gpr val 0))
(hi Gpr (value_regs_get_gpr val 1))
(mixed Gpr (x64_or $I64 lo hi)))
(lower_bmask out_ty $I64 (value_reg mixed))))
;; If the output type is I128 we just duplicate the result of the I64 lowering
(rule 2
(lower_bmask $I128 in_ty val)
(let ((res ValueRegs (lower_bmask $I64 in_ty val))
(res Gpr (value_regs_get_gpr res 0)))
(value_regs res res)))
;; Call the lower_bmask rule that does all the procssing
(rule (lower (has_type out_ty (bmask x @ (value_type in_ty))))
(lower_bmask out_ty in_ty x))
;;;; Rules for `bnot` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(rule -2 (lower (has_type ty (bnot x)))
(if (ty_int_ref_scalar_64 ty))
(x64_not ty x))
;; `i128`.
(decl i128_not (Value) ValueRegs)
(rule (i128_not x)
(let ((x_regs ValueRegs x)
(x_lo Gpr (value_regs_get_gpr x_regs 0))
(x_hi Gpr (value_regs_get_gpr x_regs 1)))
(value_gprs (x64_not $I64 x_lo)
(x64_not $I64 x_hi))))
(rule (lower (has_type $I128 (bnot x)))
(i128_not x))
;; f32 and f64
(rule -3 (lower (has_type (ty_scalar_float ty) (bnot x)))
(x64_xor_vector ty x (vector_all_ones)))
;; Special case for vector-types where bit-negation is an xor against an
;; all-one value
(rule -1 (lower (has_type ty @ (multi_lane _bits _lanes) (bnot x)))
(x64_xor_vector ty x (vector_all_ones)))
;;;; Rules for `bitselect` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty @ (multi_lane _bits _lanes)
(bitselect condition
if_true
if_false)))
;; a = and if_true, condition
;; b = and_not condition, if_false
;; or b, a
(let ((cond_xmm Xmm condition)
(a Xmm (sse_and ty if_true cond_xmm))
(b Xmm (sse_and_not ty cond_xmm if_false)))
(sse_or ty b a)))
;; If every byte of the condition is guaranteed to be all ones or all zeroes,
;; we can use x64_blend.
(rule 1 (lower (has_type ty @ (multi_lane _bits _lanes)
(bitselect condition
if_true
if_false)))
(if-let $true (use_sse41))
(if (all_ones_or_all_zeros condition))
(x64_pblendvb if_false if_true condition))
(decl pure partial all_ones_or_all_zeros (Value) bool)
(rule (all_ones_or_all_zeros (and (icmp _ _ _) (value_type (multi_lane _ _)))) $true)
(rule (all_ones_or_all_zeros (and (fcmp _ _ _) (value_type (multi_lane _ _)))) $true)
(rule (all_ones_or_all_zeros (vconst (vconst_all_ones_or_all_zeros))) $true)
(decl pure vconst_all_ones_or_all_zeros () Constant)
(extern extractor vconst_all_ones_or_all_zeros vconst_all_ones_or_all_zeros)
;; Specializations for floating-pointer compares to generate a `minp*` or a
;; `maxp*` instruction. These are equivalent to the wasm `f32x4.{pmin,pmax}`
;; instructions and how they're lowered into CLIF. Note the careful ordering
;; of all the operands here to ensure that the input CLIF matched is implemented
;; by the corresponding x64 instruction.
(rule 2 (lower (has_type $F32X4 (bitselect (bitcast _ (fcmp (FloatCC.LessThan) x y)) x y)))
(x64_minps x y))
(rule 2 (lower (has_type $F64X2 (bitselect (bitcast _ (fcmp (FloatCC.LessThan) x y)) x y)))
(x64_minpd x y))
(rule 3 (lower (has_type $F32X4 (bitselect (bitcast _ (fcmp (FloatCC.LessThan) y x)) x y)))
(x64_maxps x y))
(rule 3 (lower (has_type $F64X2 (bitselect (bitcast _ (fcmp (FloatCC.LessThan) y x)) x y)))
(x64_maxpd x y))
;; Scalar rules
(rule 3 (lower (has_type $I128 (bitselect c t f)))
(let ((a ValueRegs (and_i128 c t))
(b ValueRegs (and_i128 (i128_not c) f)))
(or_i128 a b)))
(rule 4 (lower (has_type (ty_int_ref_scalar_64 ty) (bitselect c t f)))
(let ((a Gpr (x64_and ty c t))
(b Gpr (x64_and ty (x64_not ty c) f)))
(x64_or ty a b)))
(rule 5 (lower (has_type (ty_scalar_float ty) (bitselect c t f)))
(let ((a Xmm (sse_and ty c t))
(c_neg Xmm (x64_xor_vector ty c (vector_all_ones)))
(b Xmm (sse_and ty c_neg f)))
(sse_or ty a b)))
;;;; Rules for `x86_blendv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16
(x86_blendv condition if_true if_false)))
(if-let $true (use_sse41))
(x64_pblendvb if_false if_true condition))
(rule (lower (has_type $I32X4
(x86_blendv condition if_true if_false)))
(if-let $true (use_sse41))
(x64_blendvps if_false if_true condition))
(rule (lower (has_type $I64X2
(x86_blendv condition if_true if_false)))
(if-let $true (use_sse41))
(x64_blendvpd if_false if_true condition))
;;;; Rules for `insertlane` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (insertlane vec @ (value_type ty) val (u8_from_uimm8 idx)))
(vec_insert_lane ty vec val idx))
;; Helper function used below for `insertlane` but also here for other
;; lowerings.
;;
;; Note that the `Type` used here is the type of vector the insertion is
;; happening into, or the type of the first `Reg` argument.
(decl vec_insert_lane (Type Xmm RegMem u8) Xmm)
;; i8x16.replace_lane
(rule 1 (vec_insert_lane $I8X16 vec val idx)
(if-let $true (use_sse41))
(x64_pinsrb vec val idx))
;; This lowering is particularly unoptimized and is mostly just here to work
;; rather than here to be fast. Requiring SSE 4.1 for the above lowering isn't
;; the end of the world hopefully as that's a pretty old instruction set, so
;; this is the "simplest" version that works on SSE2 for now.
;;
;; This lowering masks the original vector with a constant with all 1s except
;; for the "hole" where this value will get placed into, meaning the desired
;; lane is guaranteed as all 0s. Next the `val` is shuffled into this hole with
;; a few operations:
;;
;; 1. The `val` is zero-extended to 32-bits to guarantee the lower 32-bits
;; are all defined.
;; 2. An arithmetic shift-left is used with the low two bits of `n`, the
;; desired lane, to move the value into the right position within the 32-bit
;; register value.
;; 3. The 32-bit register is moved with `movd` into an XMM register
;; 4. The XMM register, where all lanes are 0 except for the first lane which
;; has the shifted value, is then shuffled with `pshufd` to move the
;; shifted value to the correct and final lane. This uses the upper two
;; bits of `n` to index the i32x4 lane that we're targeting.
;;
;; This all, laboriously, gets the `val` into the desired lane so it's then
;; `por`'d with the original vec-with-a-hole to produce the final result of the
;; insertion.
(rule (vec_insert_lane $I8X16 vec val n)
(let ((vec_with_hole Xmm (x64_pand vec (insert_i8x16_lane_hole n)))
(val Gpr (x64_movzx (ExtMode.BL) val))
(val Gpr (x64_shl $I32 val (Imm8Reg.Imm8 (u8_shl (u8_and n 3) 3))))
(val Xmm (x64_movd_to_xmm val))
(val_at_hole Xmm (x64_pshufd val (insert_i8x16_lane_pshufd_imm (u8_shr n 2)))))
(x64_por vec_with_hole val_at_hole)))
(decl insert_i8x16_lane_hole (u8) VCodeConstant)
(extern constructor insert_i8x16_lane_hole insert_i8x16_lane_hole)
(decl insert_i8x16_lane_pshufd_imm (u8) u8)
(rule (insert_i8x16_lane_pshufd_imm 0) 0b01_01_01_00)
(rule (insert_i8x16_lane_pshufd_imm 1) 0b01_01_00_01)
(rule (insert_i8x16_lane_pshufd_imm 2) 0b01_00_01_01)
(rule (insert_i8x16_lane_pshufd_imm 3) 0b00_01_01_01)
;; i16x8.replace_lane
(rule (vec_insert_lane $I16X8 vec val idx)
(x64_pinsrw vec val idx))
;; i32x4.replace_lane
(rule 1 (vec_insert_lane $I32X4 vec val idx)
(if-let $true (use_sse41))
(x64_pinsrd vec val idx))
(rule (vec_insert_lane $I32X4 vec val 0)
(x64_movss_regmove vec (x64_movd_to_xmm val)))
;; tmp = [ vec[1] vec[0] val[1] val[0] ]
;; result = [ vec[3] vec[2] tmp[0] tmp[2] ]
(rule (vec_insert_lane $I32X4 vec val 1)
(let ((val Xmm (x64_movd_to_xmm val))
(vec Xmm vec))
(x64_shufps (x64_punpcklqdq val vec) vec 0b11_10_00_10)))
;; tmp = [ vec[0] vec[3] val[0] val[0] ]
;; result = [ tmp[2] tmp[0] vec[1] vec[0] ]
(rule (vec_insert_lane $I32X4 vec val 2)
(let ((val Xmm (x64_movd_to_xmm val))
(vec Xmm vec))
(x64_shufps vec (x64_shufps val vec 0b00_11_00_00) 0b10_00_01_00)))
;; tmp = [ vec[3] vec[2] val[1] val[0] ]
;; result = [ tmp[0] tmp[2] vec[1] vec[0] ]
(rule (vec_insert_lane $I32X4 vec val 3)
(let ((val Xmm (x64_movd_to_xmm val))
(vec Xmm vec))
(x64_shufps vec (x64_shufps val vec 0b11_10_01_00) 0b00_10_01_00)))
;; i64x2.replace_lane
(rule 1 (vec_insert_lane $I64X2 vec val idx)
(if-let $true (use_sse41))
(x64_pinsrq vec val idx))
(rule (vec_insert_lane $I64X2 vec val 0)
(x64_movsd_regmove vec (x64_movq_to_xmm val)))
(rule (vec_insert_lane $I64X2 vec val 1)
(x64_punpcklqdq vec (x64_movq_to_xmm val)))
;; f32x4.replace_lane
(rule 1 (vec_insert_lane $F32X4 vec val idx)
(if-let $true (use_sse41))
(x64_insertps vec val (sse_insertps_lane_imm idx)))
;; f32x4.replace_lane 0 - without insertps
(rule (vec_insert_lane $F32X4 vec (RegMem.Reg val) 0)
(x64_movss_regmove vec val))
;; f32x4.replace_lane 1 - without insertps
;; tmp = [ vec[1] vec[0] val[1] val[0] ]
;; result = [ vec[3] vec[2] tmp[0] tmp[2] ]
(rule (vec_insert_lane $F32X4 vec (RegMem.Reg val) 1)
(let ((tmp Xmm (x64_movlhps val vec)))
(x64_shufps tmp vec 0b11_10_00_10)))
;; f32x4.replace_lane 2 - without insertps
;; tmp = [ vec[0] vec[3] val[0] val[0] ]
;; result = [ tmp[2] tmp[0] vec[1] vec[0] ]
(rule (vec_insert_lane $F32X4 vec (RegMem.Reg val) 2)
(let ((tmp Xmm (x64_shufps val vec 0b00_11_00_00)))
(x64_shufps vec tmp 0b10_00_01_00)))
;; f32x4.replace_lane 3 - without insertps
;; tmp = [ vec[3] vec[2] val[1] val[0] ]
;; result = [ tmp[0] tmp[2] vec[1] vec[0] ]
(rule (vec_insert_lane $F32X4 vec (RegMem.Reg val) 3)
(let ((tmp Xmm (x64_shufps val vec 0b11_10_01_00)))
(x64_shufps vec tmp 0b00_10_01_00)))
;; Recursively delegate to the above rules by loading from memory first.
(rule (vec_insert_lane $F32X4 vec (RegMem.Mem addr) idx)
(vec_insert_lane $F32X4 vec (x64_movss_load addr) idx))
;; External rust code used to calculate the immediate value to `insertps`.
(decl sse_insertps_lane_imm (u8) u8)
(extern constructor sse_insertps_lane_imm sse_insertps_lane_imm)
;; f64x2.replace_lane 0
;;
;; Here the `movsd` instruction is used specifically to specialize moving
;; into the fist lane where unlike above cases we're not using the lane
;; immediate as an immediate to the instruction itself.
(rule (vec_insert_lane $F64X2 vec (RegMem.Reg val) 0)
(x64_movsd_regmove vec val))
(rule (vec_insert_lane $F64X2 vec (RegMem.Mem val) 0)
(x64_movsd_regmove vec (x64_movsd_load val)))
;; f64x2.replace_lane 1
;;
;; Here the `movlhps` instruction is used specifically to specialize moving
;; into the second lane where unlike above cases we're not using the lane
;; immediate as an immediate to the instruction itself.
(rule (vec_insert_lane $F64X2 vec val 1)
(x64_movlhps vec val))
;;;; Rules for `smin`, `smax`, `umin`, `umax` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; `i64` and smaller.
(decl cmp_and_choose (Type CC Value Value) ValueRegs)
(rule (cmp_and_choose (fits_in_64 ty) cc x y)
(let ((size OperandSize (raw_operand_size_of_type ty))
;; We need to put x and y in registers explicitly because
;; we use the values more than once. Hence, even if these
;; are "unique uses" at the CLIF level and would otherwise
;; allow for load-op merging, here we cannot do that.
(x_reg Reg x)
(y_reg Reg y))
(with_flags_reg (x64_cmp size x_reg y_reg)
(cmove ty cc y_reg x_reg))))
(rule -1 (lower (has_type (fits_in_64 ty) (umin x y)))
(cmp_and_choose ty (CC.B) x y))
(rule -1 (lower (has_type (fits_in_64 ty) (umax x y)))
(cmp_and_choose ty (CC.NB) x y))
(rule -1 (lower (has_type (fits_in_64 ty) (smin x y)))
(cmp_and_choose ty (CC.L) x y))
(rule -1 (lower (has_type (fits_in_64 ty) (smax x y)))
(cmp_and_choose ty (CC.NL) x y))
;; SSE helpers for determining if single-instruction lowerings are available.
(decl pure has_pmins (Type) bool)
(rule 1 (has_pmins $I16X8) $true)
(rule 1 (has_pmins $I64X2) $false)
(rule (has_pmins _) (use_sse41))
(decl pure has_pmaxs (Type) bool)
(rule 1 (has_pmaxs $I16X8) $true)
(rule 1 (has_pmaxs $I64X2) $false)
(rule (has_pmaxs _) (use_sse41))
(decl pure has_pmaxu (Type) bool)
(rule 1 (has_pmaxu $I8X16) $true)
(rule 1 (has_pmaxu $I64X2) $false)
(rule (has_pmaxu _) (use_sse41))
(decl pure has_pminu (Type) bool)
(rule 1 (has_pminu $I8X16) $true)
(rule 1 (has_pminu $I64X2) $false)
(rule (has_pminu _) (use_sse41))
;; SSE `smax`.
(rule (lower (has_type (ty_vec128 ty) (smax x y)))
(lower_vec_smax ty x y))
(decl lower_vec_smax (Type Xmm Xmm) Xmm)
(rule 1 (lower_vec_smax ty x y)
(if-let $true (has_pmaxs ty))
(x64_pmaxs ty x y))
(rule (lower_vec_smax ty x y)
(let (
(x Xmm x)
(y Xmm y)
(cmp Xmm (x64_pcmpgt ty x y))
(x_is_max Xmm (x64_pand cmp x))
(y_is_max Xmm (x64_pandn cmp y))
)
(x64_por x_is_max y_is_max)))
;; SSE `smin`.
(rule 1 (lower (has_type (ty_vec128 ty) (smin x y)))
(if-let $true (has_pmins ty))
(x64_pmins ty x y))
(rule (lower (has_type (ty_vec128 ty) (smin x y)))
(let (
(x Xmm x)
(y Xmm y)
(cmp Xmm (x64_pcmpgt ty y x))
(x_is_min Xmm (x64_pand cmp x))
(y_is_min Xmm (x64_pandn cmp y))
)
(x64_por x_is_min y_is_min)))
;; SSE `umax`.
(rule 2 (lower (has_type (ty_vec128 ty) (umax x y)))
(if-let $true (has_pmaxu ty))
(x64_pmaxu ty x y))
;; If y < x then the saturating subtraction will be zero, otherwise when added
;; back to x it'll return y.
(rule 1 (lower (has_type $I16X8 (umax x y)))
(let ((x Xmm x))
(x64_paddw x (x64_psubusw y x))))
;; Flip the upper bits of each lane so the signed comparison has the same
;; result as a signed comparison, and then select the results with the output
;; mask. See `pcmpgt` lowering for info on flipping the upper bit.
(rule (lower (has_type (ty_vec128 ty) (umax x y)))
(let (
(x Xmm x)
(y Xmm y)
(mask Xmm (flip_high_bit_mask ty))
(x_masked Xmm (x64_pxor x mask))
(y_masked Xmm (x64_pxor y mask))
(cmp Xmm (x64_pcmpgt ty x_masked y_masked))
(x_is_max Xmm (x64_pand cmp x))
(y_is_max Xmm (x64_pandn cmp y))
)
(x64_por x_is_max y_is_max)))
(decl flip_high_bit_mask (Type) Xmm)
(rule (flip_high_bit_mask $I16X8)
(x64_movdqu_load (emit_u128_le_const 0x8000_8000_8000_8000_8000_8000_8000_8000)))
(rule (flip_high_bit_mask $I32X4)
(x64_movdqu_load (emit_u128_le_const 0x80000000_80000000_80000000_80000000)))
(rule (flip_high_bit_mask $I64X2)
(x64_movdqu_load (emit_u128_le_const 0x8000000000000000_8000000000000000)))
;; SSE `umin`.
(rule 2 (lower (has_type (ty_vec128 ty) (umin x y)))
(if-let $true (has_pminu ty))
(x64_pminu ty x y))
;; If x < y then the saturating subtraction will be 0. Otherwise if x > y then
;; the saturated result, when subtracted again, will go back to `y`.
(rule 1 (lower (has_type $I16X8 (umin x y)))
(let ((x Xmm x))
(x64_psubw x (x64_psubusw x y))))
;; Same as `umax`, and see `pcmpgt` for docs on flipping the upper bit.
(rule (lower (has_type (ty_vec128 ty) (umin x y)))
(let (
(x Xmm x)
(y Xmm y)
(mask Xmm (flip_high_bit_mask ty))
(x_masked Xmm (x64_pxor x mask))
(y_masked Xmm (x64_pxor y mask))
(cmp Xmm (x64_pcmpgt ty y_masked x_masked))
(x_is_max Xmm (x64_pand cmp x))
(y_is_max Xmm (x64_pandn cmp y))
)
(x64_por x_is_max y_is_max)))
;;;; Rules for `trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (trap code))
(side_effect (x64_ud2 code)))
;;;; Rules for `uadd_overflow_trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (fits_in_64 ty) (uadd_overflow_trap a b tc)))
(with_flags
(x64_add_with_flags_paired ty a b)
(trap_if (CC.B) tc)))
;; Handle lhs immediates/sinkable loads in addition to the automatic rhs
;; handling of above.
(rule 1 (lower (has_type (fits_in_64 ty)
(uadd_overflow_trap (simm32_from_value a) b tc)))
(with_flags
(x64_add_with_flags_paired ty b a)
(trap_if (CC.B) tc)))
(rule 2 (lower (has_type (fits_in_64 ty)
(uadd_overflow_trap (sinkable_load a) b tc)))
(with_flags
(x64_add_with_flags_paired ty b a)
(trap_if (CC.B) tc)))
;;;; Rules for `resumable_trap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (resumable_trap code))
(side_effect (x64_ud2 code)))
;;;; Rules for `return` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; N.B.: the Ret itself is generated by the ABI.
(rule (lower (return args))
(lower_return args))
;;;; Rules for `icmp` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule -2 (lower (icmp cc a @ (value_type (fits_in_64 ty)) b))
(lower_icmp_bool (emit_cmp cc a b)))
(rule -1 (lower (icmp cc a @ (value_type $I128) b))
(lower_icmp_bool (emit_cmp cc a b)))
;; Peephole optimization for `x < 0`, when x is a signed 64 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedLessThan) x @ (value_type $I64) (u64_from_iconst 0))))
(x64_shr $I64 x (Imm8Reg.Imm8 63)))
;; Peephole optimization for `0 > x`, when x is a signed 64 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedGreaterThan) (u64_from_iconst 0) x @ (value_type $I64))))
(x64_shr $I64 x (Imm8Reg.Imm8 63)))
;; Peephole optimization for `0 <= x`, when x is a signed 64 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedLessThanOrEqual) (u64_from_iconst 0) x @ (value_type $I64))))
(x64_shr $I64 (x64_not $I64 x) (Imm8Reg.Imm8 63)))
;; Peephole optimization for `x >= 0`, when x is a signed 64 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedGreaterThanOrEqual) x @ (value_type $I64) (u64_from_iconst 0))))
(x64_shr $I64 (x64_not $I64 x) (Imm8Reg.Imm8 63)))
;; Peephole optimization for `x < 0`, when x is a signed 32 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedLessThan) x @ (value_type $I32) (u64_from_iconst 0))))
(x64_shr $I32 x (Imm8Reg.Imm8 31)))
;; Peephole optimization for `0 > x`, when x is a signed 32 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedGreaterThan) (u64_from_iconst 0) x @ (value_type $I32))))
(x64_shr $I32 x (Imm8Reg.Imm8 31)))
;; Peephole optimization for `0 <= x`, when x is a signed 32 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedLessThanOrEqual) (u64_from_iconst 0) x @ (value_type $I32))))
(x64_shr $I32 (x64_not $I64 x) (Imm8Reg.Imm8 31)))
;; Peephole optimization for `x >= 0`, when x is a signed 32 bit value
(rule 2 (lower (has_type $I8 (icmp (IntCC.SignedGreaterThanOrEqual) x @ (value_type $I32) (u64_from_iconst 0))))
(x64_shr $I32 (x64_not $I64 x) (Imm8Reg.Imm8 31)))
;; For XMM-held values, we lower to `PCMP*` instructions, sometimes more than
;; one. To note: what is different here about the output values is that each
;; lane will be filled with all 1s or all 0s according to the comparison,
;; whereas for GPR-held values, the result will be simply 0 or 1 (upper bits
;; unset).
(rule (lower (icmp (IntCC.Equal) a @ (value_type (ty_vec128 ty)) b))
(x64_pcmpeq ty a b))
;; To lower a not-equals comparison, we perform an equality comparison
;; (PCMPEQ*) and then invert the bits (PXOR with all 1s).
(rule (lower (icmp (IntCC.NotEqual) a @ (value_type (ty_vec128 ty)) b))
(let ((checked Xmm (x64_pcmpeq ty a b))
(all_ones Xmm (vector_all_ones)))
(x64_pxor checked all_ones)))
;; SSE `sgt`
(rule (lower (icmp (IntCC.SignedGreaterThan) a @ (value_type (ty_vec128 ty)) b))
(x64_pcmpgt ty a b))
;; SSE `slt`
(rule (lower (icmp (IntCC.SignedLessThan) a @ (value_type (ty_vec128 ty)) b))
(x64_pcmpgt ty b a))
;; SSE `ugt`
;; N.B.: we must manually prevent load coalescing operands; the
;; register allocator gets confused otherwise.
(rule 1 (lower (icmp (IntCC.UnsignedGreaterThan) a @ (value_type (ty_vec128 ty)) b))
(if-let $true (has_pmaxu ty))
(let ((a Xmm a)
(b Xmm b)
(max Xmm (x64_pmaxu ty a b))
(eq Xmm (x64_pcmpeq ty max b)))
(x64_pxor eq (vector_all_ones))))
;; Flip the upper bit of each lane so the result of a signed comparison is the
;; same as the result of an unsigned comparison (see docs on `pcmpgt` for more)
(rule (lower (icmp (IntCC.UnsignedGreaterThan) a @ (value_type (ty_vec128 ty)) b))
(let ((mask Xmm (flip_high_bit_mask ty))
(a_masked Xmm (x64_pxor a mask))
(b_masked Xmm (x64_pxor b mask)))
(x64_pcmpgt ty a_masked b_masked)))
;; SSE `ult`
(rule 1 (lower (icmp (IntCC.UnsignedLessThan) a @ (value_type (ty_vec128 ty)) b))
(if-let $true (has_pminu ty))
;; N.B.: see note above.
(let ((a Xmm a)
(b Xmm b)
(min Xmm (x64_pminu ty a b))
(eq Xmm (x64_pcmpeq ty min b)))
(x64_pxor eq (vector_all_ones))))
;; Flip the upper bit of `a` and `b` so the signed comparison result will
;; be the same as the unsigned comparison result (see docs on `pcmpgt` for more).
(rule (lower (icmp (IntCC.UnsignedLessThan) a @ (value_type (ty_vec128 ty)) b))
(let ((mask Xmm (flip_high_bit_mask ty))
(a_masked Xmm (x64_pxor a mask))
(b_masked Xmm (x64_pxor b mask)))
(x64_pcmpgt ty b_masked a_masked)))
;; SSE `sge`
;; Use `pmaxs*` and compare the result to `a` to see if it's `>= b`.
(rule 1 (lower (icmp (IntCC.SignedGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(if-let $true (has_pmaxs ty))
(x64_pcmpeq ty a (x64_pmaxs ty a b)))
;; Without `pmaxs*` use a `pcmpgt*` with reversed operands and invert the
;; result.
(rule (lower (icmp (IntCC.SignedGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_pxor (x64_pcmpgt ty b a) (vector_all_ones)))
;; SSE `sle`
;; With `pmins*` use that and compare the result to `a`.
(rule 1 (lower (icmp (IntCC.SignedLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(if-let $true (has_pmins ty))
(x64_pcmpeq ty a (x64_pmins ty a b)))
;; Without `pmins*` perform a greater-than test and invert the result.
(rule (lower (icmp (IntCC.SignedLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_pxor (x64_pcmpgt ty a b) (vector_all_ones)))
;; SSE `uge`
(rule 2 (lower (icmp (IntCC.UnsignedGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(if-let $true (has_pmaxu ty))
(x64_pcmpeq ty a (x64_pmaxu ty a b)))
;; Perform a saturating subtract of `a` from `b` and if the result is zero then
;; `a` is greater or equal.
(rule 1 (lower (icmp (IntCC.UnsignedGreaterThanOrEqual) a @ (value_type $I16X8) b))
(x64_pcmpeqw (x64_psubusw b a) (xmm_zero $I16X8)))
;; Flip the upper bit of each lane so the signed comparison is the same as
;; an unsigned one and then invert the result. See docs on `pcmpgt` for why
;; flipping the upper bit works.
(rule (lower (icmp (IntCC.UnsignedGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(let (
(mask Xmm (flip_high_bit_mask ty))
(a_masked Xmm (x64_pxor a mask))
(b_masked Xmm (x64_pxor b mask))
(cmp Xmm (x64_pcmpgt ty b_masked a_masked))
)
(x64_pxor cmp (vector_all_ones))))
;; SSE `ule`
(rule 2 (lower (icmp (IntCC.UnsignedLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(if-let $true (has_pminu ty))
(x64_pcmpeq ty a (x64_pminu ty a b)))
;; A saturating subtraction will produce zeros if `a` is less than `b`, so
;; compare that result to an all-zeros result to figure out lanes of `a` that
;; are <= to the lanes in `b`
(rule 1 (lower (icmp (IntCC.UnsignedLessThanOrEqual) a @ (value_type $I16X8) b))
(let ((zeros_if_a_is_min Xmm (x64_psubusw a b)))
(x64_pcmpeqw zeros_if_a_is_min (xmm_zero $I8X16))))
;; Flip the upper bit of each lane in `a` and `b` so a signed comparison
;; produces the same result as an unsigned comparison. Then test test for `gt`
;; and invert the result to get the `le` that is desired here. See docs on
;; `pcmpgt` for why flipping the upper bit works.
(rule (lower (icmp (IntCC.UnsignedLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(let (
(mask Xmm (flip_high_bit_mask ty))
(a_masked Xmm (x64_pxor a mask))
(b_masked Xmm (x64_pxor b mask))
(cmp Xmm (x64_pcmpgt ty a_masked b_masked))
)
(x64_pxor cmp (vector_all_ones))))
;;;; Rules for `fcmp` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; CLIF's `fcmp` instruction always operates on XMM registers--both scalar and
;; vector. For the scalar versions, we use the flag-setting behavior of the
;; `UCOMIS*` instruction to `SETcc` a 0 or 1 in a GPR register. Note that CLIF's
;; `select` uses the same kind of flag-setting behavior but chooses values other
;; than 0 or 1.
;;
;; Checking the result of `UCOMIS*` is unfortunately difficult in some cases
;; because we do not have `SETcc` instructions that explicitly check
;; simultaneously for the condition (i.e., `eq`, `le`, `gt`, etc.) *and*
;; orderedness. Instead, we must check the flags multiple times. The UCOMIS*
;; documentation (see Intel's Software Developer's Manual, volume 2, chapter 4)
;; is helpful:
;; - unordered assigns Z = 1, P = 1, C = 1
;; - greater than assigns Z = 0, P = 0, C = 0
;; - less than assigns Z = 0, P = 0, C = 1
;; - equal assigns Z = 1, P = 0, C = 0
(rule -1 (lower (fcmp cc a @ (value_type (ty_scalar_float ty)) b))
(lower_fcmp_bool (emit_fcmp cc a b)))
;; For vector lowerings, we use `CMPP*` instructions with a 3-bit operand that
;; determines the comparison to make. Note that comparisons that succeed will
;; fill the lane with 1s; comparisons that do not will fill the lane with 0s.
(rule (lower (fcmp (FloatCC.Equal) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.Equal)))
(rule (lower (fcmp (FloatCC.NotEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.NotEqual)))
(rule (lower (fcmp (FloatCC.LessThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.LessThan)))
(rule (lower (fcmp (FloatCC.LessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.LessThanOrEqual)))
(rule (lower (fcmp (FloatCC.Ordered) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.Ordered)))
(rule (lower (fcmp (FloatCC.Unordered) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.Unordered)))
(rule (lower (fcmp (FloatCC.UnorderedOrGreaterThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.UnorderedOrGreaterThan)))
(rule (lower (fcmp (FloatCC.UnorderedOrGreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty a b (FcmpImm.UnorderedOrGreaterThanOrEqual)))
;; Some vector lowerings rely on flipping the operands and using a reversed
;; comparison code.
(rule (lower (fcmp (FloatCC.GreaterThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.LessThan)))
(rule (lower (fcmp (FloatCC.GreaterThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.LessThanOrEqual)))
(rule (lower (fcmp (FloatCC.UnorderedOrLessThan) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.UnorderedOrGreaterThan)))
(rule (lower (fcmp (FloatCC.UnorderedOrLessThanOrEqual) a @ (value_type (ty_vec128 ty)) b))
(x64_cmpp ty b a (FcmpImm.UnorderedOrGreaterThanOrEqual)))
;; Some vector lowerings are simply not supported for certain codes:
;; - FloatCC::OrderedNotEqual
;; - FloatCC::UnorderedOrEqual
;;;; Rules for `select` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; When a `select` has an `fcmp` as a condition then rely on `emit_fcmp` to
;; figure out how to perform the comparison.
;;
;; Note, though, that the `FloatCC.Equal` requires an "and" to happen for two
;; condition codes which isn't the easiest thing to lower to a `cmove`
;; instruction. For this reason a `select (fcmp eq ..) ..` is instead
;; flipped around to be `select (fcmp ne ..) ..` with all operands reversed.
;; This will produce a `FcmpCondResult.OrCondition` which is easier to codegen
;; for.
(rule (lower (has_type ty (select (maybe_uextend (fcmp cc a b)) x y)))
(lower_select_fcmp ty (emit_fcmp cc a b) x y))
(rule 1 (lower (has_type ty (select (maybe_uextend (fcmp (FloatCC.Equal) a b)) x y)))
(lower_select_fcmp ty (emit_fcmp (FloatCC.NotEqual) a b) y x))
(decl lower_select_fcmp (Type FcmpCondResult Value Value) InstOutput)
(rule (lower_select_fcmp ty (FcmpCondResult.Condition flags cc) x y)
(with_flags flags (cmove_from_values ty cc x y)))
(rule (lower_select_fcmp ty (FcmpCondResult.OrCondition flags cc1 cc2) x y)
(with_flags flags (cmove_or_from_values ty cc1 cc2 x y)))
;; We also can lower `select`s that depend on an `icmp` test, but more simply
;; than the `fcmp` variants above. In these cases, we lower to a `CMP`
;; instruction plus a `CMOV`; recall that `cmove_from_values` here may emit more
;; than one instruction for certain types (e.g., XMM-held, I128).
(rule (lower (has_type ty (select (maybe_uextend (icmp cc a @ (value_type (fits_in_64 a_ty)) b)) x y)))
(let ((size OperandSize (raw_operand_size_of_type a_ty)))
(with_flags (x64_cmp size b a) (cmove_from_values ty cc x y))))
;; Finally, we lower `select` from a condition value `c`. These rules are meant
;; to be the final, default lowerings if no other patterns matched above.
(rule -1 (lower (has_type ty (select c @ (value_type (fits_in_64 a_ty)) x y)))
(let ((size OperandSize (raw_operand_size_of_type a_ty))
;; N.B.: disallow load-op fusion, see above. TODO:
;; https://github.com/bytecodealliance/wasmtime/issues/3953.
(gpr_c Gpr (put_in_gpr c)))
(with_flags (x64_test size gpr_c gpr_c) (cmove_from_values ty (CC.NZ) x y))))
(rule -2 (lower (has_type ty (select c @ (value_type $I128) x y)))
(let ((cond_result IcmpCondResult (cmp_zero_i128 (CC.Z) c)))
(select_icmp cond_result x y)))
;; Specializations for floating-point compares to generate a `mins*` or a
;; `maxs*` instruction. These are equivalent to the "pseudo-m{in,ax}"
;; specializations for vectors.
(rule 2 (lower (has_type $F32 (select (maybe_uextend (fcmp (FloatCC.LessThan) x y)) x y)))
(x64_minss x y))
(rule 2 (lower (has_type $F64 (select (maybe_uextend (fcmp (FloatCC.LessThan) x y)) x y)))
(x64_minsd x y))
(rule 3 (lower (has_type $F32 (select (maybe_uextend (fcmp (FloatCC.LessThan) y x)) x y)))
(x64_maxss x y))
(rule 3 (lower (has_type $F64 (select (maybe_uextend (fcmp (FloatCC.LessThan) y x)) x y)))
(x64_maxsd x y))
;; Rules for `clz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; If available, we can use a plain lzcnt instruction here. Note no
;; special handling is required for zero inputs, because the machine
;; instruction does what the CLIF expects for zero, i.e. it returns
;; zero.
(rule 3 (lower (has_type (ty_32_or_64 ty) (clz src)))
(if-let $true (use_lzcnt))
(x64_lzcnt ty src))
(rule 2 (lower (has_type (ty_32_or_64 ty) (clz src)))
(do_clz ty ty src))
(rule 1 (lower
(has_type (ty_8_or_16 ty)
(clz src)))
(do_clz $I32 ty (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule 0 (lower
(has_type $I128
(clz src)))
(let ((upper Gpr (do_clz $I64 $I64 (value_regs_get_gpr src 1)))
(lower Gpr (x64_add $I64
(do_clz $I64 $I64 (value_regs_get_gpr src 0))
(RegMemImm.Imm 64)))
(result_lo Gpr
(with_flags_reg
(x64_cmp_imm (OperandSize.Size64) 64 upper)
(cmove $I64 (CC.NZ) upper lower))))
(value_regs result_lo (imm $I64 0))))
;; Implementation helper for clz; operates on 32 or 64-bit units.
(decl do_clz (Type Type Gpr) Gpr)
(rule (do_clz ty orig_ty src)
(let ((highest_bit_index Reg (bsr_or_else ty src (imm_i64 $I64 -1)))
(bits_minus_1 Reg (imm ty (u64_sub (ty_bits_u64 orig_ty) 1))))
(x64_sub ty bits_minus_1 highest_bit_index)))
;; Rules for `ctz` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Analogous to `clz` cases above, but using mirror instructions
;; (tzcnt vs lzcnt, bsf vs bsr).
(rule 3 (lower (has_type (ty_32_or_64 ty) (ctz src)))
(if-let $true (use_bmi1))
(x64_tzcnt ty src))
(rule 2 (lower (has_type (ty_32_or_64 ty) (ctz src)))
(do_ctz ty ty src))
(rule 1 (lower
(has_type (ty_8_or_16 ty)
(ctz src)))
(do_ctz $I32 ty (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule 0 (lower
(has_type $I128
(ctz src)))
(let ((lower Gpr (do_ctz $I64 $I64 (value_regs_get_gpr src 0)))
(upper Gpr (x64_add $I64
(do_ctz $I64 $I64 (value_regs_get_gpr src 1))
(RegMemImm.Imm 64)))
(result_lo Gpr
(with_flags_reg
(x64_cmp_imm (OperandSize.Size64) 64 lower)
(cmove $I64 (CC.Z) upper lower))))
(value_regs result_lo (imm $I64 0))))
(decl do_ctz (Type Type Gpr) Gpr)
(rule (do_ctz ty orig_ty src)
(bsf_or_else ty src (imm $I64 (ty_bits_u64 orig_ty))))
;; Rules for `popcnt` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 4 (lower (has_type (ty_32_or_64 ty) (popcnt src)))
(if-let $true (use_popcnt))
(x64_popcnt ty src))
(rule 3 (lower (has_type (ty_8_or_16 ty) (popcnt src)))
(if-let $true (use_popcnt))
(x64_popcnt $I32 (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule 1 (lower (has_type $I128 (popcnt src)))
(if-let $true (use_popcnt))
(let ((lo_count Gpr (x64_popcnt $I64 (value_regs_get_gpr src 0)))
(hi_count Gpr (x64_popcnt $I64 (value_regs_get_gpr src 1))))
(value_regs (x64_add $I64 lo_count hi_count) (imm $I64 0))))
(rule -1 (lower
(has_type (ty_32_or_64 ty)
(popcnt src)))
(do_popcnt ty src))
(rule -2 (lower
(has_type (ty_8_or_16 ty)
(popcnt src)))
(do_popcnt $I32 (extend_to_gpr src $I32 (ExtendKind.Zero))))
(rule (lower
(has_type $I128
(popcnt src)))
(let ((lo_count Gpr (do_popcnt $I64 (value_regs_get_gpr src 0)))
(hi_count Gpr (do_popcnt $I64 (value_regs_get_gpr src 1))))
(value_regs (x64_add $I64 lo_count hi_count) (imm $I64 0))))
;; Implementation of popcount when we don't nave a native popcount
;; instruction.
(decl do_popcnt (Type Gpr) Gpr)
(rule (do_popcnt $I64 src)
(let ((shifted1 Gpr (x64_shr $I64 src (Imm8Reg.Imm8 1)))
(sevens Gpr (imm $I64 0x7777777777777777))
(masked1 Gpr (x64_and $I64 shifted1 sevens))
;; diff1 := src - ((src >> 1) & 0b0111_0111_0111...)
(diff1 Gpr (x64_sub $I64 src masked1))
(shifted2 Gpr (x64_shr $I64 masked1 (Imm8Reg.Imm8 1)))
(masked2 Gpr (x64_and $I64 shifted2 sevens))
;; diff2 := diff1 - ((diff1 >> 1) & 0b0111_0111_0111...)
(diff2 Gpr (x64_sub $I64 diff1 masked2))
(shifted3 Gpr (x64_shr $I64 masked2 (Imm8Reg.Imm8 1)))
(masked3 Gpr (x64_and $I64 shifted3 sevens))
;; diff3 := diff2 - ((diff2 >> 1) & 0b0111_0111_0111...)
;;
;; At this point, each nibble of diff3 is the popcount of
;; that nibble. This works because at each step above, we
;; are basically subtracting floor(value / 2) from the
;; running value; the leftover remainder is 1 if the LSB
;; was 1. After three steps, we have (nibble / 8) -- 0 or
;; 1 for the MSB of the nibble -- plus three possible
;; additions for the three other bits.
(diff3 Gpr (x64_sub $I64 diff2 masked3))
;; Add the two nibbles of each byte together.
(sum1 Gpr (x64_add $I64
(x64_shr $I64 diff3 (Imm8Reg.Imm8 4))
diff3))
;; Mask the above sum to have the popcount for each byte
;; in the lower nibble of that byte.
(ofof Gpr (imm $I64 0x0f0f0f0f0f0f0f0f))
(masked4 Gpr (x64_and $I64 sum1 ofof))
(ones Gpr (imm $I64 0x0101010101010101))
;; Use a multiply to sum all of the bytes' popcounts into
;; the top byte. Consider the binomial expansion for the
;; top byte: it is the sum of the bytes (masked4 >> 56) *
;; 0x01 + (masked4 >> 48) * 0x01 + (masked4 >> 40) * 0x01
;; + ... + (masked4 >> 0).
(mul Gpr (x64_mul $I64 masked4 ones))
;; Now take that top byte and return it as the popcount.
(final Gpr (x64_shr $I64 mul (Imm8Reg.Imm8 56))))
final))
;; This is the 32-bit version of the above; the steps for each nibble
;; are the same, we just use constants half as wide.
(rule (do_popcnt $I32 src)
(let ((shifted1 Gpr (x64_shr $I32 src (Imm8Reg.Imm8 1)))
(sevens Gpr (imm $I32 0x77777777))
(masked1 Gpr (x64_and $I32 shifted1 sevens))
(diff1 Gpr (x64_sub $I32 src masked1))
(shifted2 Gpr (x64_shr $I32 masked1 (Imm8Reg.Imm8 1)))
(masked2 Gpr (x64_and $I32 shifted2 sevens))
(diff2 Gpr (x64_sub $I32 diff1 masked2))
(shifted3 Gpr (x64_shr $I32 masked2 (Imm8Reg.Imm8 1)))
(masked3 Gpr (x64_and $I32 shifted3 sevens))
(diff3 Gpr (x64_sub $I32 diff2 masked3))
(sum1 Gpr (x64_add $I32
(x64_shr $I32 diff3 (Imm8Reg.Imm8 4))
diff3))
(masked4 Gpr (x64_and $I32 sum1 (RegMemImm.Imm 0x0f0f0f0f)))
(mul Gpr (x64_mul $I32 masked4 (RegMemImm.Imm 0x01010101)))
(final Gpr (x64_shr $I32 mul (Imm8Reg.Imm8 24))))
final))
(rule 2 (lower (has_type $I8X16 (popcnt src)))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512bitalg))
(x64_vpopcntb src))
;; For SSE 4.2 we use Mula's algorithm (https://arxiv.org/pdf/1611.07612.pdf):
;;
;; __m128i count_bytes ( __m128i v) {
;; __m128i lookup = _mm_setr_epi8(0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4);
;; __m128i low_mask = _mm_set1_epi8 (0x0f);
;; __m128i lo = _mm_and_si128 (v, low_mask);
;; __m128i hi = _mm_and_si128 (_mm_srli_epi16 (v, 4), low_mask);
;; __m128i cnt1 = _mm_shuffle_epi8 (lookup, lo);
;; __m128i cnt2 = _mm_shuffle_epi8 (lookup, hi);
;; return _mm_add_epi8 (cnt1, cnt2);
;; }
;;
;; Details of the above algorithm can be found in the reference noted above, but the basics
;; are to create a lookup table that pre populates the popcnt values for each number [0,15].
;; The algorithm uses shifts to isolate 4 bit sections of the vector, pshufb as part of the
;; lookup process, and adds together the results.
;;
;; __m128i lookup = _mm_setr_epi8(0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4);
(rule 1 (lower (has_type $I8X16 (popcnt src)))
(if-let $true (use_ssse3))
(let ((low_mask XmmMem (emit_u128_le_const 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f))
(low_nibbles Xmm (sse_and $I8X16 src low_mask))
;; Note that this is a 16x8 shift, but that's OK; we mask
;; off anything that traverses from one byte to the next
;; with the low_mask below.
(shifted_src Xmm (x64_psrlw src (xmi_imm 4)))
(high_nibbles Xmm (sse_and $I8X16 shifted_src low_mask))
(lookup Xmm (x64_xmm_load_const $I8X16
(emit_u128_le_const 0x04030302_03020201_03020201_02010100)))
(bit_counts_low Xmm (x64_pshufb lookup low_nibbles))
(bit_counts_high Xmm (x64_pshufb lookup high_nibbles)))
(x64_paddb bit_counts_low bit_counts_high)))
;; A modified version of the popcnt method from Hacker's Delight.
(rule (lower (has_type $I8X16 (popcnt src)))
(let ((mask1 XmmMem (emit_u128_le_const 0x77777777777777777777777777777777))
(src Xmm src)
(shifted Xmm (x64_pand (x64_psrlq src (xmi_imm 1)) mask1))
(src Xmm (x64_psubb src shifted))
(shifted Xmm (x64_pand (x64_psrlq shifted (xmi_imm 1)) mask1))
(src Xmm (x64_psubb src shifted))
(shifted Xmm (x64_pand (x64_psrlq shifted (xmi_imm 1)) mask1))
(src Xmm (x64_psubb src shifted))
(src Xmm (x64_paddb src (x64_psrlw src (xmi_imm 4)))))
(x64_pand src (emit_u128_le_const 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f))))
;; Rules for `bitrev` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8 (bitrev src)))
(do_bitrev8 $I32 src))
(rule (lower (has_type $I16 (bitrev src)))
(do_bitrev16 $I32 src))
(rule (lower (has_type $I32 (bitrev src)))
(do_bitrev32 $I32 src))
(rule (lower (has_type $I64 (bitrev src)))
(do_bitrev64 $I64 src))
(rule (lower (has_type $I128 (bitrev src)))
(value_regs
(do_bitrev64 $I64 (value_regs_get_gpr src 1))
(do_bitrev64 $I64 (value_regs_get_gpr src 0))))
(decl do_bitrev8 (Type Gpr) Gpr)
(rule (do_bitrev8 ty src)
(let ((tymask u64 (ty_mask ty))
(mask1 Gpr (imm ty (u64_and tymask 0x5555555555555555)))
(lo1 Gpr (x64_and ty src mask1))
(hi1 Gpr (x64_and ty (x64_shr ty src (Imm8Reg.Imm8 1)) mask1))
(swap1 Gpr (x64_or ty
(x64_shl ty lo1 (Imm8Reg.Imm8 1))
hi1))
(mask2 Gpr (imm ty (u64_and tymask 0x3333333333333333)))
(lo2 Gpr (x64_and ty swap1 mask2))
(hi2 Gpr (x64_and ty (x64_shr ty swap1 (Imm8Reg.Imm8 2)) mask2))
(swap2 Gpr (x64_or ty
(x64_shl ty lo2 (Imm8Reg.Imm8 2))
hi2))
(mask4 Gpr (imm ty (u64_and tymask 0x0f0f0f0f0f0f0f0f)))
(lo4 Gpr (x64_and ty swap2 mask4))
(hi4 Gpr (x64_and ty (x64_shr ty swap2 (Imm8Reg.Imm8 4)) mask4))
(swap4 Gpr (x64_or ty
(x64_shl ty lo4 (Imm8Reg.Imm8 4))
hi4)))
swap4))
(decl do_bitrev16 (Type Gpr) Gpr)
(rule (do_bitrev16 ty src)
(let ((src_ Gpr (do_bitrev8 ty src))
(tymask u64 (ty_mask ty))
(mask8 Gpr (imm ty (u64_and tymask 0x00ff00ff00ff00ff)))
(lo8 Gpr (x64_and ty src_ mask8))
(hi8 Gpr (x64_and ty (x64_shr ty src_ (Imm8Reg.Imm8 8)) mask8))
(swap8 Gpr (x64_or ty
(x64_shl ty lo8 (Imm8Reg.Imm8 8))
hi8)))
swap8))
(decl do_bitrev32 (Type Gpr) Gpr)
(rule (do_bitrev32 ty src)
(let ((src_ Gpr (do_bitrev16 ty src))
(tymask u64 (ty_mask ty))
(mask16 Gpr (imm ty (u64_and tymask 0x0000ffff0000ffff)))
(lo16 Gpr (x64_and ty src_ mask16))
(hi16 Gpr (x64_and ty (x64_shr ty src_ (Imm8Reg.Imm8 16)) mask16))
(swap16 Gpr (x64_or ty
(x64_shl ty lo16 (Imm8Reg.Imm8 16))
hi16)))
swap16))
(decl do_bitrev64 (Type Gpr) Gpr)
(rule (do_bitrev64 ty @ $I64 src)
(let ((src_ Gpr (do_bitrev32 ty src))
(mask32 Gpr (imm ty 0xffffffff))
(lo32 Gpr (x64_and ty src_ mask32))
(hi32 Gpr (x64_shr ty src_ (Imm8Reg.Imm8 32)))
(swap32 Gpr (x64_or ty
(x64_shl ty lo32 (Imm8Reg.Imm8 32))
hi32)))
swap32))
;; Rules for `bswap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; x64 bswap instruction is only for 32- or 64-bit swaps
;; implement the 16-bit swap as a rotl by 8
(rule (lower (has_type $I16 (bswap src)))
(x64_rotl $I16 src (Imm8Reg.Imm8 8)))
(rule (lower (has_type $I32 (bswap src)))
(x64_bswap $I32 src))
(rule (lower (has_type $I64 (bswap src)))
(x64_bswap $I64 src))
(rule (lower (has_type $I128 (bswap src)))
(value_regs
(x64_bswap $I64 (value_regs_get_gpr src 1))
(x64_bswap $I64 (value_regs_get_gpr src 0))))
;; Rules for `is_null` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Null references are represented by the constant value `0`.
(rule (lower (is_null src @ (value_type $R64)))
(with_flags
(x64_cmp_imm (OperandSize.Size64) 0 src)
(x64_setcc (CC.Z))))
;; Rules for `is_invalid` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Invalid references are represented by the constant value `-1`.
(rule (lower (is_invalid src @ (value_type $R64)))
(with_flags
(x64_cmp_imm (OperandSize.Size64) 0xffffffff src) ;; simm32 0xffff_ffff is sign-extended to -1.
(x64_setcc (CC.Z))))
;; Rules for `uextend` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; I{8,16,32,64} -> I128.
(rule (lower (has_type $I128 (uextend src)))
(value_regs (extend_to_gpr src $I64 (ExtendKind.Zero)) (imm $I64 0)))
;; I{8,16,32} -> I64.
(rule (lower (has_type $I64 (uextend src)))
(extend_to_gpr src $I64 (ExtendKind.Zero)))
;; I{8,16} -> I32
;; I8 -> I16
(rule -1 (lower (has_type (fits_in_32 _) (uextend src)))
(extend_to_gpr src $I32 (ExtendKind.Zero)))
;; Rules for `sextend` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; I{8,16,32} -> I128.
;;
;; Produce upper 64 bits sign-extended from lower 64: shift right by
;; 63 bits to spread the sign bit across the result.
(rule (lower (has_type $I128 (sextend src)))
(let ((lo Gpr (extend_to_gpr src $I64 (ExtendKind.Sign)))
(hi Gpr (x64_sar $I64 lo (Imm8Reg.Imm8 63))))
(value_regs lo hi)))
;; I{8,16,32} -> I64.
(rule (lower (has_type $I64 (sextend src)))
(extend_to_gpr src $I64 (ExtendKind.Sign)))
;; I{8,16} -> I32
;; I8 -> I16
(rule -1 (lower (has_type (fits_in_32 _) (sextend src)))
(extend_to_gpr src $I32 (ExtendKind.Sign)))
;; Rules for `ireduce` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; T -> T is always a no-op, even I128 -> I128.
(rule (lower (has_type ty (ireduce src @ (value_type ty))))
src)
;; T -> I{64,32,16,8}: We can simply pass through the value: values
;; are always stored with high bits undefined, so we can just leave
;; them be.
(rule 1 (lower (has_type (fits_in_64 ty) (ireduce src)))
(value_regs_get_gpr src 0))
;; Rules for `debugtrap` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (debugtrap))
(side_effect (x64_hlt)))
;; Rules for `x86_pmaddubsw` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I16X8 (x86_pmaddubsw x y)))
(if-let $true (use_ssse3))
(x64_pmaddubsw y x))
;; Rules for `fadd` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fadd x y)))
(x64_addss x y))
(rule (lower (has_type $F64 (fadd x y)))
(x64_addsd x y))
(rule (lower (has_type $F32X4 (fadd x y)))
(x64_addps x y))
(rule (lower (has_type $F64X2 (fadd x y)))
(x64_addpd x y))
;; The above rules automatically sink loads for rhs operands, so additionally
;; add rules for sinking loads with lhs operands.
(rule 1 (lower (has_type $F32 (fadd (sinkable_load x) y)))
(x64_addss y x))
(rule 1 (lower (has_type $F64 (fadd (sinkable_load x) y)))
(x64_addsd y x))
(rule 1 (lower (has_type $F32X4 (fadd (sinkable_load x) y)))
(x64_addps y x))
(rule 1 (lower (has_type $F64X2 (fadd (sinkable_load x) y)))
(x64_addpd y x))
;; Rules for `fsub` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fsub x y)))
(x64_subss x y))
(rule (lower (has_type $F64 (fsub x y)))
(x64_subsd x y))
(rule (lower (has_type $F32X4 (fsub x y)))
(x64_subps x y))
(rule (lower (has_type $F64X2 (fsub x y)))
(x64_subpd x y))
;; Rules for `fmul` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmul x y)))
(x64_mulss x y))
(rule (lower (has_type $F64 (fmul x y)))
(x64_mulsd x y))
(rule (lower (has_type $F32X4 (fmul x y)))
(x64_mulps x y))
(rule (lower (has_type $F64X2 (fmul x y)))
(x64_mulpd x y))
;; The above rules automatically sink loads for rhs operands, so additionally
;; add rules for sinking loads with lhs operands.
(rule 1 (lower (has_type $F32 (fmul (sinkable_load x) y)))
(x64_mulss y x))
(rule 1 (lower (has_type $F64 (fmul (sinkable_load x) y)))
(x64_mulsd y x))
(rule 1 (lower (has_type $F32X4 (fmul (sinkable_load x) y)))
(x64_mulps y x))
(rule 1 (lower (has_type $F64X2 (fmul (sinkable_load x) y)))
(x64_mulpd y x))
;; Rules for `fdiv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fdiv x y)))
(x64_divss x y))
(rule (lower (has_type $F64 (fdiv x y)))
(x64_divsd x y))
(rule (lower (has_type $F32X4 (fdiv x y)))
(x64_divps x y))
(rule (lower (has_type $F64X2 (fdiv x y)))
(x64_divpd x y))
;; Rules for `sqrt` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (sqrt x)))
(x64_sqrtss x))
(rule (lower (has_type $F64 (sqrt x)))
(x64_sqrtsd x))
(rule (lower (has_type $F32X4 (sqrt x)))
(x64_sqrtps x))
(rule (lower (has_type $F64X2 (sqrt x)))
(x64_sqrtpd x))
;; Rules for `fpromote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F64 (fpromote x)))
(x64_cvtss2sd x))
;; Rules for `fvpromote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F64X2 (fvpromote_low x)))
(x64_cvtps2pd (put_in_xmm x)))
;; Rules for `fdemote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fdemote x)))
(x64_cvtsd2ss x))
;; Rules for `fvdemote` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32X4 (fvdemote x)))
(x64_cvtpd2ps x))
;; Rules for `fmin` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmin x y)))
(xmm_min_max_seq $F32 $true x y))
(rule (lower (has_type $F64 (fmin x y)))
(xmm_min_max_seq $F64 $true x y))
;; Vector-typed version. We don't use single pseudoinstructions as
;; above, because we don't need to generate a mini-CFG. Instead, we
;; perform a branchless series of operations.
;;
;; We cannot simply use native min instructions (minps, minpd) because
;; NaN handling is different per CLIF semantics than on
;; x86. Specifically, if an argument is NaN, or the arguments are both
;; zero but of opposite signs, then the x86 instruction always
;; produces the second argument. However, per CLIF semantics, we
;; require that fmin(NaN, _) = fmin(_, NaN) = NaN, and fmin(+0, -0) =
;; fmin(-0, +0) = -0.
(rule (lower (has_type $F32X4 (fmin x y)))
;; Compute min(x, y) and min(y, x) with native
;; instructions. These will differ in one of the edge cases
;; above that we have to handle properly. (Conversely, if they
;; don't differ, then the native instruction's answer is the
;; right one per CLIF semantics.)
(let ((min1 Xmm (x64_minps x y))
(min2 Xmm (x64_minps y x))
;; Compute the OR of the two. Note that NaNs have an
;; exponent field of all-ones (0xFF for F32), so if either
;; result is a NaN, this OR will be. And if either is a
;; zero (which has an exponent of 0 and mantissa of 0),
;; this captures a sign-bit of 1 (negative) if either
;; input is negative.
;;
;; In the case where we don't have a +/-0 mismatch or
;; NaNs, then `min1` and `min2` are equal and `min_or` is
;; the correct minimum.
(min_or Xmm (x64_orps min1 min2))
;; "compare unordered" produces a true mask (all ones) in
;; a given lane if the min is a NaN. We use this to
;; generate a mask to ensure quiet NaNs.
(is_nan_mask Xmm (x64_cmpps min_or min2 (FcmpImm.Unordered)))
;; OR in the NaN mask.
(min_or_2 Xmm (x64_orps min_or is_nan_mask))
;; Shift the NaN mask down so that it covers just the
;; fraction below the NaN signalling bit; we'll use this
;; to mask off non-canonical NaN payloads.
;;
;; All-ones for NaN, shifted down to leave 10 top bits (1
;; sign, 8 exponent, 1 QNaN bit that must remain set)
;; cleared.
(nan_fraction_mask Xmm (x64_psrld is_nan_mask (xmi_imm 10)))
;; Do a NAND, so that we retain every bit not set in
;; `nan_fraction_mask`. This mask will be all zeroes (so
;; we retain every bit) in non-NaN cases, and will have
;; ones (so we clear those bits) in NaN-payload bits
;; otherwise.
(final Xmm (x64_andnps nan_fraction_mask min_or_2)))
final))
;; Likewise for F64 lanes, except that the right-shift is by 13 bits
;; (1 sign, 11 exponent, 1 QNaN bit).
(rule (lower (has_type $F64X2 (fmin x y)))
(let ((min1 Xmm (x64_minpd x y))
(min2 Xmm (x64_minpd y x))
(min_or Xmm (x64_orpd min1 min2))
(is_nan_mask Xmm (x64_cmppd min1 min2 (FcmpImm.Unordered)))
(min_or_2 Xmm (x64_orpd min_or is_nan_mask))
(nan_fraction_mask Xmm (x64_psrlq is_nan_mask (xmi_imm 13)))
(final Xmm (x64_andnpd nan_fraction_mask min_or_2)))
final))
;; Rules for `fmax` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fmax x y)))
(xmm_min_max_seq $F32 $false x y))
(rule (lower (has_type $F64 (fmax x y)))
(xmm_min_max_seq $F64 $false x y))
;; The vector version of fmax here is a dual to the fmin sequence
;; above, almost, with a few differences.
(rule (lower (has_type $F32X4 (fmax x y)))
;; Compute max(x, y) and max(y, x) with native
;; instructions. These will differ in one of the edge cases
;; above that we have to handle properly. (Conversely, if they
;; don't differ, then the native instruction's answer is the
;; right one per CLIF semantics.)
(let ((max1 Xmm (x64_maxps x y))
(max2 Xmm (x64_maxps y x))
;; Compute the XOR of the two maxima. In the case
;; where we don't have a +/-0 mismatch or NaNs, then
;; `min1` and `min2` are equal and this XOR is zero.
(max_xor Xmm (x64_xorps max1 max2))
;; OR the XOR into one of the original maxima. If they are
;; equal, this does nothing. If max2 was NaN, its exponent
;; bits were all-ones, so the xor's exponent bits were the
;; complement of max1, and the OR of max1 and max_xor has
;; an all-ones exponent (is a NaN). If max1 was NaN, then
;; its exponent bits were already all-ones, so the OR will
;; be a NaN as well.
(max_blended_nan Xmm (x64_orps max1 max_xor))
;; Subtract the XOR. This ensures that if we had +0 and
;; -0, we end up with +0.
(max_blended_nan_positive Xmm (x64_subps max_blended_nan max_xor))
;; "compare unordered" produces a true mask (all ones) in
;; a given lane if the min is a NaN. We use this to
;; generate a mask to ensure quiet NaNs.
(is_nan_mask Xmm (x64_cmpps max_blended_nan max_blended_nan (FcmpImm.Unordered)))
;; Shift the NaN mask down so that it covers just the
;; fraction below the NaN signalling bit; we'll use this
;; to mask off non-canonical NaN payloads.
;;
;; All-ones for NaN, shifted down to leave 10 top bits (1
;; sign, 8 exponent, 1 QNaN bit that must remain set)
;; cleared.
(nan_fraction_mask Xmm (x64_psrld is_nan_mask (xmi_imm 10)))
;; Do a NAND, so that we retain every bit not set in
;; `nan_fraction_mask`. This mask will be all zeroes (so
;; we retain every bit) in non-NaN cases, and will have
;; ones (so we clear those bits) in NaN-payload bits
;; otherwise.
(final Xmm (x64_andnps nan_fraction_mask max_blended_nan_positive)))
final))
(rule (lower (has_type $F64X2 (fmax x y)))
;; Compute max(x, y) and max(y, x) with native
;; instructions. These will differ in one of the edge cases
;; above that we have to handle properly. (Conversely, if they
;; don't differ, then the native instruction's answer is the
;; right one per CLIF semantics.)
(let ((max1 Xmm (x64_maxpd x y))
(max2 Xmm (x64_maxpd y x))
;; Compute the XOR of the two maxima. In the case
;; where we don't have a +/-0 mismatch or NaNs, then
;; `min1` and `min2` are equal and this XOR is zero.
(max_xor Xmm (x64_xorpd max1 max2))
;; OR the XOR into one of the original maxima. If they are
;; equal, this does nothing. If max2 was NaN, its exponent
;; bits were all-ones, so the xor's exponent bits were the
;; complement of max1, and the OR of max1 and max_xor has
;; an all-ones exponent (is a NaN). If max1 was NaN, then
;; its exponent bits were already all-ones, so the OR will
;; be a NaN as well.
(max_blended_nan Xmm (x64_orpd max1 max_xor))
;; Subtract the XOR. This ensures that if we had +0 and
;; -0, we end up with +0.
(max_blended_nan_positive Xmm (x64_subpd max_blended_nan max_xor))
;; `cmpps` with predicate index `3` is `cmpunordps`, or
;; "compare unordered": it produces a true mask (all ones)
;; in a given lane if the min is a NaN. We use this to
;; generate a mask to ensure quiet NaNs.
(is_nan_mask Xmm (x64_cmppd max_blended_nan max_blended_nan (FcmpImm.Unordered)))
;; Shift the NaN mask down so that it covers just the
;; fraction below the NaN signalling bit; we'll use this
;; to mask off non-canonical NaN payloads.
;;
;; All-ones for NaN, shifted down to leave 13 top bits (1
;; sign, 11 exponent, 1 QNaN bit that must remain set)
;; cleared.
(nan_fraction_mask Xmm (x64_psrlq is_nan_mask (xmi_imm 13)))
;; Do a NAND, so that we retain every bit not set in
;; `nan_fraction_mask`. This mask will be all zeroes (so
;; we retain every bit) in non-NaN cases, and will have
;; ones (so we clear those bits) in NaN-payload bits
;; otherwise.
(final Xmm (x64_andnpd nan_fraction_mask max_blended_nan_positive)))
final))
;; Rules for `fma` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Base case for fma is to call out to one of two libcalls. For vectors they
;; need to be decomposed, handle each element individually, and then recomposed.
(rule (lower (has_type $F32 (fma x y z)))
(libcall_3 (LibCall.FmaF32) x y z))
(rule (lower (has_type $F64 (fma x y z)))
(libcall_3 (LibCall.FmaF64) x y z))
(rule (lower (has_type $F32X4 (fma x y z)))
(let (
(x Xmm (put_in_xmm x))
(y Xmm (put_in_xmm y))
(z Xmm (put_in_xmm z))
(x0 Xmm (libcall_3 (LibCall.FmaF32) x y z))
(x1 Xmm (libcall_3 (LibCall.FmaF32)
(x64_pshufd x 1)
(x64_pshufd y 1)
(x64_pshufd z 1)))
(x2 Xmm (libcall_3 (LibCall.FmaF32)
(x64_pshufd x 2)
(x64_pshufd y 2)
(x64_pshufd z 2)))
(x3 Xmm (libcall_3 (LibCall.FmaF32)
(x64_pshufd x 3)
(x64_pshufd y 3)
(x64_pshufd z 3)))
(tmp Xmm (vec_insert_lane $F32X4 x0 x1 1))
(tmp Xmm (vec_insert_lane $F32X4 tmp x2 2))
(tmp Xmm (vec_insert_lane $F32X4 tmp x3 3))
)
tmp))
(rule (lower (has_type $F64X2 (fma x y z)))
(let (
(x Xmm (put_in_xmm x))
(y Xmm (put_in_xmm y))
(z Xmm (put_in_xmm z))
(x0 Xmm (libcall_3 (LibCall.FmaF64) x y z))
(x1 Xmm (libcall_3 (LibCall.FmaF64)
(x64_pshufd x 0xee)
(x64_pshufd y 0xee)
(x64_pshufd z 0xee)))
)
(vec_insert_lane $F64X2 x0 x1 1)))
;; Special case for when the `fma` feature is active and a native instruction
;; can be used.
(rule 1 (lower (has_type ty (fma x y z)))
(if-let $true (use_fma))
(fmadd ty x y z))
(decl fmadd (Type Value Value Value) Xmm)
(decl fnmadd (Type Value Value Value) Xmm)
;; Base case. Note that this will automatically sink a load with `z`, the value
;; to add.
(rule (fmadd ty x y z) (x64_vfmadd213 ty x y z))
;; Allow sinking loads with one of the two values being multiplied in addition
;; to the value being added. Note that both x and y can be sunk here due to
;; multiplication being commutative.
(rule 1 (fmadd ty (sinkable_load x) y z) (x64_vfmadd132 ty y z x))
(rule 2 (fmadd ty x (sinkable_load y) z) (x64_vfmadd132 ty x z y))
;; If one of the values being multiplied is negated then use a `vfnmadd*`
;; instruction instead
(rule 3 (fmadd ty (fneg x) y z) (fnmadd ty x y z))
(rule 4 (fmadd ty x (fneg y) z) (fnmadd ty x y z))
(rule (fnmadd ty x y z) (x64_vfnmadd213 ty x y z))
(rule 1 (fnmadd ty (sinkable_load x) y z) (x64_vfnmadd132 ty y z x))
(rule 2 (fnmadd ty x (sinkable_load y) z) (x64_vfnmadd132 ty x z y))
;; Like `fmadd` if one argument is negated switch which one is being codegen'd
(rule 3 (fnmadd ty (fneg x) y z) (fmadd ty x y z))
(rule 4 (fnmadd ty x (fneg y) z) (fmadd ty x y z))
;; Rules for `load*` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; In order to load a value from memory to a GPR register, we may need to extend
;; the loaded value from 8-, 16-, or 32-bits to this backend's expected GPR
;; width: 64 bits. Note that `ext_mode` will load 1-bit types (booleans) as
;; 8-bit loads.
;;
;; By default, we zero-extend all sub-64-bit loads to a GPR.
(rule -4 (lower (has_type (and (fits_in_32 ty) (is_gpr_type _)) (load flags address offset)))
(x64_movzx (ext_mode (ty_bits_u16 ty) 64) (to_amode flags address offset)))
;; But if we know that both the `from` and `to` are 64 bits, we simply load with
;; no extension.
(rule -1 (lower (has_type (ty_int_ref_64 ty) (load flags address offset)))
(x64_mov (to_amode flags address offset)))
;; Also, certain scalar loads have a specific `from` width and extension kind
;; (signed -> `sx`, zeroed -> `zx`). We overwrite the high bits of the 64-bit
;; GPR even if the `to` type is smaller (e.g., 16-bits).
(rule (lower (has_type (is_gpr_type ty) (uload8 flags address offset)))
(x64_movzx (ExtMode.BQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (sload8 flags address offset)))
(x64_movsx (ExtMode.BQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (uload16 flags address offset)))
(x64_movzx (ExtMode.WQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (sload16 flags address offset)))
(x64_movsx (ExtMode.WQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (uload32 flags address offset)))
(x64_movzx (ExtMode.LQ) (to_amode flags address offset)))
(rule (lower (has_type (is_gpr_type ty) (sload32 flags address offset)))
(x64_movsx (ExtMode.LQ) (to_amode flags address offset)))
;; To load to XMM registers, we use the x64-specific instructions for each type.
;; For `$F32` and `$F64` this is important--we only want to load 32 or 64 bits.
;; But for the 128-bit types, this is not strictly necessary for performance but
;; might help with clarity during disassembly.
(rule (lower (has_type $F32 (load flags address offset)))
(x64_movss_load (to_amode flags address offset)))
(rule (lower (has_type $F64 (load flags address offset)))
(x64_movsd_load (to_amode flags address offset)))
(rule (lower (has_type $F32X4 (load flags address offset)))
(x64_movups_load (to_amode flags address offset)))
(rule (lower (has_type $F64X2 (load flags address offset)))
(x64_movupd_load (to_amode flags address offset)))
(rule -2 (lower (has_type (ty_vec128 ty) (load flags address offset)))
(x64_movdqu_load (to_amode flags address offset)))
;; We can load an I128 by doing two 64-bit loads.
(rule -3 (lower (has_type $I128
(load flags address offset)))
(let ((addr_lo Amode (to_amode flags address offset))
(addr_hi Amode (amode_offset addr_lo 8))
(value_lo Reg (x64_mov addr_lo))
(value_hi Reg (x64_mov addr_hi)))
(value_regs value_lo value_hi)))
;; We also include widening vector loads; these sign- or zero-extend each lane
;; to the next wider width (e.g., 16x4 -> 32x4).
(rule 1 (lower (has_type $I16X8 (sload8x8 flags address offset)))
(if-let $true (use_sse41))
(x64_pmovsxbw (to_amode flags address offset)))
(rule 1 (lower (has_type $I16X8 (uload8x8 flags address offset)))
(if-let $true (use_sse41))
(x64_pmovzxbw (to_amode flags address offset)))
(rule 1 (lower (has_type $I32X4 (sload16x4 flags address offset)))
(if-let $true (use_sse41))
(x64_pmovsxwd (to_amode flags address offset)))
(rule 1 (lower (has_type $I32X4 (uload16x4 flags address offset)))
(if-let $true (use_sse41))
(x64_pmovzxwd (to_amode flags address offset)))
(rule 1 (lower (has_type $I64X2 (sload32x2 flags address offset)))
(if-let $true (use_sse41))
(x64_pmovsxdq (to_amode flags address offset)))
(rule 1 (lower (has_type $I64X2 (uload32x2 flags address offset)))
(if-let $true (use_sse41))
(x64_pmovzxdq (to_amode flags address offset)))
(rule (lower (has_type $I16X8 (sload8x8 flags address offset)))
(lower_swiden_low $I16X8 (x64_movq_to_xmm (to_amode flags address offset))))
(rule (lower (has_type $I16X8 (uload8x8 flags address offset)))
(lower_uwiden_low $I16X8 (x64_movq_to_xmm (to_amode flags address offset))))
(rule (lower (has_type $I32X4 (sload16x4 flags address offset)))
(lower_swiden_low $I32X4 (x64_movq_to_xmm (to_amode flags address offset))))
(rule (lower (has_type $I32X4 (uload16x4 flags address offset)))
(lower_uwiden_low $I32X4 (x64_movq_to_xmm (to_amode flags address offset))))
(rule (lower (has_type $I64X2 (sload32x2 flags address offset)))
(lower_swiden_low $I64X2 (x64_movq_to_xmm (to_amode flags address offset))))
(rule (lower (has_type $I64X2 (uload32x2 flags address offset)))
(lower_uwiden_low $I64X2 (x64_movq_to_xmm (to_amode flags address offset))))
;; Rules for `store*` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; 8-, 16-, 32- and 64-bit GPR stores.
(rule -2 (lower (store flags
value @ (value_type (is_gpr_type ty))
address
offset))
(side_effect
(x64_movrm ty (to_amode flags address offset) value)))
;; Explicit 8/16/32-bit opcodes.
(rule (lower (istore8 flags value address offset))
(side_effect
(x64_movrm $I8 (to_amode flags address offset) value)))
(rule (lower (istore16 flags value address offset))
(side_effect
(x64_movrm $I16 (to_amode flags address offset) value)))
(rule (lower (istore32 flags value address offset))
(side_effect
(x64_movrm $I32 (to_amode flags address offset) value)))
;; IMM stores
(rule 2 (lower (store flags (has_type (fits_in_64 ty) (iconst (simm32 value))) address offset))
(side_effect
(x64_movimm_m ty (to_amode flags address offset) value)))
;; F32 stores of values in XMM registers.
(rule 1 (lower (store flags
value @ (value_type $F32)
address
offset))
(side_effect
(x64_movss_store (to_amode flags address offset) value)))
;; F64 stores of values in XMM registers.
(rule 1 (lower (store flags
value @ (value_type $F64)
address
offset))
(side_effect
(x64_movsd_store (to_amode flags address offset) value)))
;; Stores of F32X4 vectors.
(rule 1 (lower (store flags
value @ (value_type $F32X4)
address
offset))
(side_effect
(x64_movups_store (to_amode flags address offset) value)))
;; Stores of F64X2 vectors.
(rule 1 (lower (store flags
value @ (value_type $F64X2)
address
offset))
(side_effect
(x64_movupd_store (to_amode flags address offset) value)))
;; Stores of all other 128-bit vector types with integer lanes.
(rule -1 (lower (store flags
value @ (value_type (ty_vec128_int _))
address
offset))
(side_effect
(x64_movdqu_store (to_amode flags address offset) value)))
;; Stores of I128 values: store the two 64-bit halves separately.
(rule 0 (lower (store flags
value @ (value_type $I128)
address
offset))
(let ((value_reg ValueRegs value)
(value_lo Gpr (value_regs_get_gpr value_reg 0))
(value_hi Gpr (value_regs_get_gpr value_reg 1))
(addr_lo Amode (to_amode flags address offset))
(addr_hi Amode (amode_offset addr_lo 8)))
(side_effect
(side_effect_concat
(x64_movrm $I64 addr_lo value_lo)
(x64_movrm $I64 addr_hi value_hi)))))
;; Slightly optimize the extraction of the first lane from a vector which is
;; stored in memory. In the case the first lane specifically is selected the
;; standard `movss` and `movsd` instructions can be used as-if we're storing a
;; f32 or f64 despite the source perhaps being an integer vector since the
;; result of the instruction is the same.
(rule 2 (lower (store flags
(has_type $F32 (extractlane value (u8_from_uimm8 0)))
address
offset))
(side_effect
(x64_movss_store (to_amode flags address offset) value)))
(rule 2 (lower (store flags
(has_type $F64 (extractlane value (u8_from_uimm8 0)))
address
offset))
(side_effect
(x64_movsd_store (to_amode flags address offset) value)))
(rule 2 (lower (store flags
(has_type $I8 (extractlane value (u8_from_uimm8 n)))
address
offset))
(if-let $true (use_sse41))
(side_effect
(x64_pextrb_store (to_amode flags address offset) value n)))
(rule 2 (lower (store flags
(has_type $I16 (extractlane value (u8_from_uimm8 n)))
address
offset))
(if-let $true (use_sse41))
(side_effect
(x64_pextrw_store (to_amode flags address offset) value n)))
(rule 2 (lower (store flags
(has_type $I32 (extractlane value (u8_from_uimm8 n)))
address
offset))
(if-let $true (use_sse41))
(side_effect
(x64_pextrd_store (to_amode flags address offset) value n)))
(rule 2 (lower (store flags
(has_type $I64 (extractlane value (u8_from_uimm8 n)))
address
offset))
(if-let $true (use_sse41))
(side_effect
(x64_pextrq_store (to_amode flags address offset) value n)))
;; Rules for `load*` + ALU op + `store*` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Add mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(iadd (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_add_mem ty (to_amode flags addr offset) src2))))
;; Add mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(iadd src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_add_mem ty (to_amode flags addr offset) src2))))
;; Sub mem, reg
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(isub (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_sub_mem ty (to_amode flags addr offset) src2))))
;; And mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(band (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_and_mem ty (to_amode flags addr offset) src2))))
;; And mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(band src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_and_mem ty (to_amode flags addr offset) src2))))
;; Or mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bor (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_or_mem ty (to_amode flags addr offset) src2))))
;; Or mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bor src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_or_mem ty (to_amode flags addr offset) src2))))
;; Xor mem, reg
(rule 3 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bxor (and
(sinkable_load sink)
(load flags addr offset))
src2))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_xor_mem ty (to_amode flags addr offset) src2))))
;; Xor mem, reg with args swapped
(rule 2 (lower
(store flags
(has_type (ty_32_or_64 ty)
(bxor src2
(and
(sinkable_load sink)
(load flags addr offset))))
addr
offset))
(let ((_ RegMemImm sink))
(side_effect
(x64_xor_mem ty (to_amode flags addr offset) src2))))
;; Rules for `fence` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (fence))
(side_effect (x64_mfence)))
;; Rules for `func_addr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (func_addr (func_ref_data _ extname dist)))
(load_ext_name extname 0 dist))
;; Rules for `symbol_value` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (symbol_value (symbol_value_data extname dist offset)))
(load_ext_name extname offset dist))
;; Rules for `atomic_load` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This is a normal load. The x86-TSO memory model provides sufficient
;; sequencing to satisfy the CLIF synchronisation requirements for `AtomicLoad`
;; without the need for any fence instructions.
;;
;; As described in the `atomic_load` documentation, this lowering is only valid
;; for I8, I16, I32, and I64. The sub-64-bit types are zero extended, as with a
;; normal load.
(rule 1 (lower (has_type $I64 (atomic_load flags address)))
(x64_mov (to_amode flags address (zero_offset))))
(rule (lower (has_type (and (fits_in_32 ty) (ty_int _)) (atomic_load flags address)))
(x64_movzx (ext_mode (ty_bits_u16 ty) 64) (to_amode flags address (zero_offset))))
;; Rules for `atomic_store` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This is a normal store followed by an `mfence` instruction. As described in
;; the `atomic_load` documentation, this lowering is only valid for I8, I16,
;; I32, and I64.
(rule (lower (atomic_store flags
value @ (value_type (and (fits_in_64 ty) (ty_int _)))
address))
(side_effect (side_effect_concat
(x64_movrm ty (to_amode flags address (zero_offset)) value)
(x64_mfence))))
;; Rules for `atomic_cas` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (and (fits_in_64 ty) (ty_int _))
(atomic_cas flags address expected replacement)))
(x64_cmpxchg ty expected replacement (to_amode flags address (zero_offset))))
;; Rules for `atomic_rmw` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; This is a simple, general-case atomic update, based on a loop involving
;; `cmpxchg`. Note that we could do much better than this in the case where the
;; old value at the location (that is to say, the SSA `Value` computed by this
;; CLIF instruction) is not required. In that case, we could instead implement
;; this using a single `lock`-prefixed x64 read-modify-write instruction. Also,
;; even in the case where the old value is required, for the `add` and `sub`
;; cases, we can use the single instruction `lock xadd`. However, those
;; improvements have been left for another day. TODO: filed as
;; https://github.com/bytecodealliance/wasmtime/issues/2153.
(rule (lower (has_type (and (fits_in_64 ty) (ty_int _))
(atomic_rmw flags op address input)))
(x64_atomic_rmw_seq ty op (to_amode flags address (zero_offset)) input))
;; Rules for `call` and `call_indirect` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (call (func_ref_data sig_ref extname dist) inputs))
(gen_call sig_ref extname dist inputs))
(rule (lower (call_indirect sig_ref val inputs))
(gen_call_indirect sig_ref val inputs))
;;;; Rules for `return_call` and `return_call_indirect` ;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (return_call (func_ref_data sig_ref extname dist) args))
(gen_return_call sig_ref extname dist args))
(rule (lower (return_call_indirect sig_ref callee args))
(gen_return_call_indirect sig_ref callee args))
;;;; Rules for `get_{frame,stack}_pointer` and `get_return_address` ;;;;;;;;;;;;
(rule (lower (get_frame_pointer))
(x64_rbp))
(rule (lower (get_stack_pointer))
(x64_rsp))
(rule (lower (get_return_address))
(x64_load $I64
(Amode.ImmReg 8 (x64_rbp) (mem_flags_trusted))
(ExtKind.None)))
;; Rules for `jump` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (jump _) (single_target target))
(emit_side_effect (jmp_known target)))
;; Rules for `brif` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower_branch (brif (maybe_uextend (icmp cc a b)) _ _) (two_targets then else))
(emit_side_effect (jmp_cond_icmp (emit_cmp cc a b) then else)))
(rule 2 (lower_branch (brif (maybe_uextend (fcmp cc a b)) _ _) (two_targets then else))
(emit_side_effect (jmp_cond_fcmp (emit_fcmp cc a b) then else)))
(rule 1 (lower_branch (brif val @ (value_type $I128) _ _)
(two_targets then else))
(emit_side_effect (jmp_cond_icmp (cmp_zero_i128 (CC.Z) val) then else)))
(rule (lower_branch (brif val @ (value_type (ty_int_bool_or_ref)) _ _)
(two_targets then else))
(emit_side_effect (with_flags_side_effect
(cmp_zero_int_bool_ref val)
(jmp_cond (CC.NZ) then else))))
;; Compare an I128 value to zero, returning a flags result suitable for making a
;; jump decision. The comparison is implemented as `(hi == 0) && (low == 0)`,
;; and the result can be interpreted as follows
;; * CC.Z indicates that the value was non-zero, as one or both of the halves of
;; the value were non-zero
;; * CC.NZ indicates that both halves of the value were 0
(decl cmp_zero_i128 (CC ValueRegs) IcmpCondResult)
(rule (cmp_zero_i128 (cc_nz_or_z cc) val)
(let ((lo Gpr (value_regs_get_gpr val 0))
(hi Gpr (value_regs_get_gpr val 1))
(lo_z Gpr (with_flags_reg (x64_cmp (OperandSize.Size64) (RegMemImm.Imm 0) lo)
(x64_setcc (CC.Z))))
(hi_z Gpr (with_flags_reg (x64_cmp (OperandSize.Size64) (RegMemImm.Imm 0) hi)
(x64_setcc (CC.Z)))))
(icmp_cond_result (x64_test (OperandSize.Size8) lo_z hi_z) cc)))
(decl cmp_zero_int_bool_ref (Value) ProducesFlags)
(rule (cmp_zero_int_bool_ref val @ (value_type ty))
(let ((size OperandSize (raw_operand_size_of_type ty))
(src Gpr val))
(x64_test size src src)))
;; Rules for `br_table` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower_branch (br_table idx @ (value_type ty) _) (jump_table_targets default_target jt_targets))
(let ((size OperandSize (raw_operand_size_of_type ty))
(jt_size u32 (jump_table_size jt_targets))
(size_reg Reg (imm ty (u32_as_u64 jt_size)))
(idx_reg Gpr (extend_to_gpr idx $I64 (ExtendKind.Zero)))
(clamped_idx Reg (with_flags_reg
(x64_cmp size size_reg idx_reg)
(cmove ty (CC.B) idx_reg size_reg))))
(emit_side_effect (jmp_table_seq ty clamped_idx default_target jt_targets))))
;; Rules for `select_spectre_guard` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (select_spectre_guard (icmp cc a b) x y))
(select_icmp (emit_cmp cc a b) x y))
(rule -1 (lower (has_type ty (select_spectre_guard c @ (value_type (fits_in_64 a_ty)) x y)))
(let ((size OperandSize (raw_operand_size_of_type a_ty))
(gpr_c Gpr (put_in_gpr c)))
(with_flags (x64_test size gpr_c gpr_c) (cmove_from_values ty (CC.NZ) x y))))
(rule -2 (lower (has_type ty (select_spectre_guard c @ (value_type $I128) x y)))
(let ((cond_result IcmpCondResult (cmp_zero_i128 (CC.Z) c)))
(select_icmp cond_result x y)))
;; Rules for `fcvt_from_sint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Note that the `cvtsi2s{s,d}` instruction is not just an int-to-float
;; conversion instruction in isolation, it also takes the upper 64-bits of an
;; xmm register and places it into the destination. We don't actually want that
;; to happen as it could accidentally create a false dependency with a
;; previous instruction defining the register's upper 64-bits. See #7085 for
;; an instance of this.
;;
;; This means that the first operand to all of the int-to-float conversions here
;; are `(xmm_zero)` operands which is a guaranteed zero register that has no
;; dependencies on other instructions.
;;
;; Ideally this would be lifted out to a higher level to get deduplicated
;; between consecutive int-to-float operations but that's not easy
;; to do at this time. One possibility would be a mid-end rule which rewrites
;; `fcvt_from_sint` to an x86-specific opcode using a zero constant which would
;; be subject to normal LICM, but that's not feasible today.
(rule 2 (lower (has_type $F32 (fcvt_from_sint a @ (value_type $I8))))
(x64_cvtsi2ss $I32 (xmm_zero $F32X4) (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 2 (lower (has_type $F32 (fcvt_from_sint a @ (value_type $I16))))
(x64_cvtsi2ss $I32 (xmm_zero $F32X4) (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 1 (lower (has_type $F32 (fcvt_from_sint a @ (value_type (ty_int (fits_in_64 ty))))))
(x64_cvtsi2ss ty (xmm_zero $F32X4) a))
(rule 2 (lower (has_type $F64 (fcvt_from_sint a @ (value_type $I8))))
(x64_cvtsi2sd $I32 (xmm_zero $F64X2) (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 2 (lower (has_type $F64 (fcvt_from_sint a @ (value_type $I16))))
(x64_cvtsi2sd $I32 (xmm_zero $F64X2) (extend_to_gpr a $I32 (ExtendKind.Sign))))
(rule 1 (lower (has_type $F64 (fcvt_from_sint a @ (value_type (ty_int (fits_in_64 ty))))))
(x64_cvtsi2sd ty (xmm_zero $F64X2) a))
(rule 0 (lower (fcvt_from_sint a @ (value_type $I32X4)))
(x64_cvtdq2ps a))
(rule 1 (lower (has_type $F64X2 (fcvt_from_sint (swiden_low a @ (value_type $I32X4)))))
(x64_cvtdq2pd a))
;; Rules for `fcvt_from_uint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (has_type $F32 (fcvt_from_uint val @ (value_type (fits_in_32 (ty_int ty))))))
(x64_cvtsi2ss $I64 (xmm_zero $F32X4) (extend_to_gpr val $I64 (ExtendKind.Zero))))
(rule 1 (lower (has_type $F64 (fcvt_from_uint val @ (value_type (fits_in_32 (ty_int ty))))))
(x64_cvtsi2sd $I64 (xmm_zero $F64X2) (extend_to_gpr val $I64 (ExtendKind.Zero))))
(rule (lower (has_type ty (fcvt_from_uint val @ (value_type $I64))))
(cvt_u64_to_float_seq ty val))
;; Algorithm uses unpcklps to help create a float that is equivalent
;; 0x1.0p52 + double(src). 0x1.0p52 is unique because at this exponent
;; every value of the mantissa represents a corresponding uint32 number.
;; When we subtract 0x1.0p52 we are left with double(src).
(rule 1 (lower (has_type $F64X2 (fcvt_from_uint (uwiden_low val @ (value_type $I32X4)))))
(let ((uint_mask XmmMem (emit_u128_le_const 0x43300000_43300000))
(res Xmm (x64_unpcklps val uint_mask))
(uint_mask_high XmmMem (emit_u128_le_const 0x4330000000000000_4330000000000000)))
(x64_subpd res uint_mask_high)))
;; When AVX512VL and AVX512F are available,
;; `fcvt_from_uint` can be lowered to a single instruction.
(rule 2 (lower (has_type $F32X4 (fcvt_from_uint src)))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512f))
(x64_vcvtudq2ps src))
;; Converting packed unsigned integers to packed floats
;; requires a few steps. There is no single instruction
;; lowering for converting unsigned floats but there is for
;; converting packed signed integers to float (cvtdq2ps). In
;; the steps below we isolate the upper half (16 bits) and
;; lower half (16 bits) of each lane and then we convert
;; each half separately using cvtdq2ps meant for signed
;; integers. In order for this to work for the upper half
;; bits we must shift right by 1 (divide by 2) these bits in
;; order to ensure the most significant bit is 0 not signed,
;; and then after the conversion we double the value.
;; Finally we add the converted values where addition will
;; correctly round.
;;
;; Sequence:
;; -> A = 0xffffffff
;; -> Ah = 0xffff0000
;; -> Al = 0x0000ffff
;; -> Convert(Al) // Convert int to float
;; -> Ah = Ah >> 1 // Shift right 1 to assure Ah conversion isn't treated as signed
;; -> Convert(Ah) // Convert .. with no loss of significant digits from previous shift
;; -> Ah = Ah + Ah // Double Ah to account for shift right before the conversion.
;; -> dst = Ah + Al // Add the two floats together
(rule 1 (lower (has_type $F32X4 (fcvt_from_uint val)))
(let ((a Xmm val)
;; get the low 16 bits
(a_lo Xmm (x64_pslld a (xmi_imm 16)))
(a_lo Xmm (x64_psrld a_lo (xmi_imm 16)))
;; get the high 16 bits
(a_hi Xmm (x64_psubd a a_lo))
;; convert the low 16 bits
(a_lo Xmm (x64_cvtdq2ps a_lo))
;; shift the high bits by 1, convert, and double to get the correct
;; value
(a_hi Xmm (x64_psrld a_hi (xmi_imm 1)))
(a_hi Xmm (x64_cvtdq2ps a_hi))
(a_hi Xmm (x64_addps a_hi a_hi)))
;; add together the two converted values
(x64_addps a_hi a_lo)))
;; Rules for `fcvt_to_uint` and `fcvt_to_sint` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type out_ty (fcvt_to_uint val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_uint_seq out_ty val $false))
(rule (lower (has_type out_ty (fcvt_to_uint_sat val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_uint_seq out_ty val $true))
(rule (lower (has_type out_ty (fcvt_to_sint val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_sint_seq out_ty val $false))
(rule (lower (has_type out_ty (fcvt_to_sint_sat val @ (value_type (ty_scalar_float _)))))
(cvt_float_to_sint_seq out_ty val $true))
;; The x64 backend currently only supports these two type combinations.
(rule 1 (lower (has_type $I32X4 (fcvt_to_sint_sat val @ (value_type $F32X4))))
(let ((src Xmm val)
;; Sets tmp to zero if float is NaN
(tmp Xmm (x64_cmpps src src (FcmpImm.Equal)))
(dst Xmm (x64_andps src tmp))
;; Sets top bit of tmp if float is positive
;; Setting up to set top bit on negative float values
(tmp Xmm (x64_pxor tmp dst))
;; Convert the packed float to packed doubleword.
(dst Xmm (x64_cvttps2dq dst))
;; Set top bit only if < 0
(tmp Xmm (x64_pand dst tmp))
(tmp Xmm (x64_psrad tmp (xmi_imm 31))))
;; On overflow 0x80000000 is returned to a lane.
;; Below sets positive overflow lanes to 0x7FFFFFFF
;; Keeps negative overflow lanes as is.
(x64_pxor tmp dst)))
;; The algorithm for converting floats to unsigned ints is a little tricky. The
;; complication arises because we are converting from a signed 64-bit int with a positive
;; integer range from 1..INT_MAX (0x1..0x7FFFFFFF) to an unsigned integer with an extended
;; range from (INT_MAX+1)..UINT_MAX. It's this range from (INT_MAX+1)..UINT_MAX
;; (0x80000000..0xFFFFFFFF) that needs to be accounted for as a special case since our
;; conversion instruction (cvttps2dq) only converts as high as INT_MAX (0x7FFFFFFF), but
;; which conveniently setting underflows and overflows (smaller than MIN_INT or larger than
;; MAX_INT) to be INT_MAX+1 (0x80000000). Nothing that the range (INT_MAX+1)..UINT_MAX includes
;; precisely INT_MAX values we can correctly account for and convert every value in this range
;; if we simply subtract INT_MAX+1 before doing the cvttps2dq conversion. After the subtraction
;; every value originally (INT_MAX+1)..UINT_MAX is now the range (0..INT_MAX).
;; After the conversion we add INT_MAX+1 back to this converted value, noting again that
;; values we are trying to account for were already set to INT_MAX+1 during the original conversion.
;; We simply have to create a mask and make sure we are adding together only the lanes that need
;; to be accounted for. Digesting it all the steps then are:
;;
;; Step 1 - Account for NaN and negative floats by setting these src values to zero.
;; Step 2 - Make a copy (tmp1) of the src value since we need to convert twice for
;; reasons described above.
;; Step 3 - Convert the original src values. This will convert properly all floats up to INT_MAX
;; Step 4 - Subtract INT_MAX from the copy set (tmp1). Note, all zero and negative values are those
;; values that were originally in the range (0..INT_MAX). This will come in handy during
;; step 7 when we zero negative lanes.
;; Step 5 - Create a bit mask for tmp1 that will correspond to all lanes originally less than
;; UINT_MAX that are now less than INT_MAX thanks to the subtraction.
;; Step 6 - Convert the second set of values (tmp1)
;; Step 7 - Prep the converted second set by zeroing out negative lanes (these have already been
;; converted correctly with the first set) and by setting overflow lanes to 0x7FFFFFFF
;; as this will allow us to properly saturate overflow lanes when adding to 0x80000000
;; Step 8 - Add the orginal converted src and the converted tmp1 where float values originally less
;; than and equal to INT_MAX will be unchanged, float values originally between INT_MAX+1 and
;; UINT_MAX will add together (INT_MAX) + (SRC - INT_MAX), and float values originally
;; greater than UINT_MAX will be saturated to UINT_MAX (0xFFFFFFFF) after adding (0x8000000 + 0x7FFFFFFF).
;;
;;
;; The table below illustrates the result after each step where it matters for the converted set.
;; Note the original value range (original src set) is the final dst in Step 8:
;;
;; Original src set:
;; | Original Value Range | Step 1 | Step 3 | Step 8 |
;; | -FLT_MIN..FLT_MAX | 0.0..FLT_MAX | 0..INT_MAX(w/overflow) | 0..UINT_MAX(w/saturation) |
;;
;; Copied src set (tmp1):
;; | Step 2 | Step 4 |
;; | 0.0..FLT_MAX | (0.0-(INT_MAX+1))..(FLT_MAX-(INT_MAX+1)) |
;;
;; | Step 6 | Step 7 |
;; | (0-(INT_MAX+1))..(UINT_MAX-(INT_MAX+1))(w/overflow) | ((INT_MAX+1)-(INT_MAX+1))..(INT_MAX+1) |
(rule 1 (lower (has_type $I32X4 (fcvt_to_uint_sat val @ (value_type $F32X4))))
(let ((src Xmm val)
;; Converting to unsigned int so if float src is negative or NaN
;; will first set to zero.
(tmp2 Xmm (xmm_zero $F32X4))
(dst Xmm (x64_maxps src tmp2))
;; Set tmp2 to INT_MAX+1. It is important to note here that after it looks
;; like we are only converting INT_MAX (0x7FFFFFFF) but in fact because
;; single precision IEEE-754 floats can only accurately represent contingous
;; integers up to 2^23 and outside of this range it rounds to the closest
;; integer that it can represent. In the case of INT_MAX, this value gets
;; represented as 0x4f000000 which is the integer value (INT_MAX+1).
(tmp2 Xmm (x64_pcmpeqd tmp2 tmp2))
(tmp2 Xmm (x64_psrld tmp2 (xmi_imm 1)))
(tmp2 Xmm (x64_cvtdq2ps tmp2))
;; Make a copy of these lanes and then do the first conversion.
;; Overflow lanes greater than the maximum allowed signed value will
;; set to 0x80000000. Negative and NaN lanes will be 0x0
(tmp1 Xmm dst)
(dst Xmm (x64_cvttps2dq dst))
;; Set lanes to src - max_signed_int
(tmp1 Xmm (x64_subps tmp1 tmp2))
;; Create mask for all positive lanes to saturate (i.e. greater than
;; or equal to the maxmimum allowable unsigned int).
(tmp2 Xmm (x64_cmpps tmp2 tmp1 (FcmpImm.LessThanOrEqual)))
;; Convert those set of lanes that have the max_signed_int factored out.
(tmp1 Xmm (x64_cvttps2dq tmp1))
;; Prepare converted lanes by zeroing negative lanes and prepping lanes
;; that have positive overflow (based on the mask) by setting these lanes
;; to 0x7FFFFFFF
(tmp1 Xmm (x64_pxor tmp1 tmp2))
(tmp2 Xmm (xmm_zero $I32X4))
(tmp1 Xmm (lower_vec_smax $I32X4 tmp1 tmp2)))
;; Add this second set of converted lanes to the original to properly handle
;; values greater than max signed int.
(x64_paddd tmp1 dst)))
;; Rules for `x86_cvtt2dq` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I32X4 (x86_cvtt2dq val @ (value_type $F32X4))))
(x64_cvttps2dq val))
;; Rules for `iadd_pairwise` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16 (iadd_pairwise x y)))
(let (
;; Shuffle all the even lanes of `x` and `y` into one register
(even_lane_mask Xmm (x64_movdqu_load (emit_u128_le_const 0x00ff_00ff_00ff_00ff_00ff_00ff_00ff_00ff)))
(x_evens Xmm (x64_pand x even_lane_mask))
(y_evens Xmm (x64_pand y even_lane_mask))
(evens Xmm (x64_packuswb x_evens y_evens))
;; Shuffle all the odd lanes of `x` and `y` into one register
(x_odds Xmm (x64_psrlw x (xmi_imm 8)))
(y_odds Xmm (x64_psrlw y (xmi_imm 8)))
(odds Xmm (x64_packuswb x_odds y_odds))
)
(x64_paddb evens odds)))
(rule 1 (lower (has_type $I16X8 (iadd_pairwise x y)))
(if-let $true (use_ssse3))
(x64_phaddw x y))
(rule (lower (has_type $I16X8 (iadd_pairwise x y)))
(let (
(x Xmm x)
(y Xmm y)
;; Shuffle the even-numbered 16-bit lanes into low four lanes of each
;; vector by shuffling 16-bit lanes then shuffling 32-bit lanes.
;; With these in place generate a new vector from the two low 64-bits
;; of each vector (the low four 16-bit lanes).
;;
;; 0xe8 == 0b11_10_10_00
(x_evens Xmm (x64_pshufd (x64_pshufhw (x64_pshuflw x 0xe8) 0xe8) 0xe8))
(y_evens Xmm (x64_pshufd (x64_pshufhw (x64_pshuflw y 0xe8) 0xe8) 0xe8))
(evens Xmm (x64_punpcklqdq x_evens y_evens))
;; Shuffle the odd-numbered 16-bit lanes into the low 8 lanes by
;; performing `sshr` operation on 32-bit lanes, effectively moving the
;; odd lanes into even lanes while leaving their sign bits in the
;; odd lanes. The `packssdw` instruction then conveniently will
;; put everything into one vector for us.
(x_shifted Xmm (x64_psrad x (xmi_imm 16)))
(y_shifted Xmm (x64_psrad y (xmi_imm 16)))
(odds Xmm (x64_packssdw x_shifted y_shifted))
)
(x64_paddw evens odds)))
(rule 1 (lower (has_type $I32X4 (iadd_pairwise x y)))
(if-let $true (use_ssse3))
(x64_phaddd x y))
(rule (lower (has_type $I32X4 (iadd_pairwise x y)))
(let (
(x Xmm x)
(y Xmm y)
;; evens = [ x[0] x[2] y[0] y[2] ]
(evens Xmm (x64_shufps x y 0b10_00_10_00))
;; odds = [ x[1] x[3] y[1] y[3] ]
(odds Xmm (x64_shufps x y 0b11_01_11_01))
)
(x64_paddd evens odds)))
;; special case for the `i16x8.extadd_pairwise_i8x16_s` wasm instruction
(rule 2 (lower
(has_type $I16X8 (iadd_pairwise
(swiden_low val @ (value_type $I8X16))
(swiden_high val))))
(if-let $true (use_ssse3))
(let ((mul_const Xmm (x64_xmm_load_const $I8X16
(emit_u128_le_const 0x01010101010101010101010101010101))))
(x64_pmaddubsw mul_const val)))
;; special case for the `i32x4.extadd_pairwise_i16x8_s` wasm instruction
(rule 2 (lower
(has_type $I32X4 (iadd_pairwise
(swiden_low val @ (value_type $I16X8))
(swiden_high val))))
(let ((mul_const XmmMem (emit_u128_le_const 0x0001_0001_0001_0001_0001_0001_0001_0001)))
(x64_pmaddwd val mul_const)))
;; special case for the `i16x8.extadd_pairwise_i8x16_u` wasm instruction
(rule 2 (lower
(has_type $I16X8 (iadd_pairwise
(uwiden_low val @ (value_type $I8X16))
(uwiden_high val))))
(if-let $true (use_ssse3))
(let ((mul_const XmmMem (emit_u128_le_const 0x01010101010101010101010101010101)))
(x64_pmaddubsw val mul_const)))
;; special case for the `i32x4.extadd_pairwise_i16x8_u` wasm instruction
(rule 2 (lower
(has_type $I32X4 (iadd_pairwise
(uwiden_low val @ (value_type $I16X8))
(uwiden_high val))))
(let ((xor_const XmmMem (emit_u128_le_const 0x8000_8000_8000_8000_8000_8000_8000_8000))
(dst Xmm (x64_pxor val xor_const))
(madd_const XmmMem (emit_u128_le_const 0x0001_0001_0001_0001_0001_0001_0001_0001))
(dst Xmm (x64_pmaddwd dst madd_const))
(addd_const XmmMem (emit_u128_le_const 0x00010000_00010000_00010000_00010000)))
(x64_paddd dst addd_const)))
;; special case for the `i32x4.dot_i16x8_s` wasm instruction
(rule 2 (lower
(has_type $I32X4 (iadd_pairwise
(imul (swiden_low x) (swiden_low y))
(imul (swiden_high x) (swiden_high y)))))
(x64_pmaddwd x y))
;; Rules for `swiden_low` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; With SSE4.1 use the `pmovsx*` instructions for this
(rule 1 (lower (has_type $I16X8 (swiden_low val @ (value_type $I8X16))))
(if-let $true (use_sse41))
(x64_pmovsxbw val))
(rule 1 (lower (has_type $I32X4 (swiden_low val @ (value_type $I16X8))))
(if-let $true (use_sse41))
(x64_pmovsxwd val))
(rule 1 (lower (has_type $I64X2 (swiden_low val @ (value_type $I32X4))))
(if-let $true (use_sse41))
(x64_pmovsxdq val))
(rule (lower (has_type ty (swiden_low val))) (lower_swiden_low ty val))
(decl lower_swiden_low (Type Xmm) Xmm)
;; Duplicate the low lanes next to each other, then perform a wider shift-right
;; by the low lane width to move the upper of each pair back into the lower lane
;; of each pair, achieving the widening of the lower lanes.
(rule (lower_swiden_low $I16X8 val)
(x64_psraw (x64_punpcklbw val val) (xmi_imm 8)))
(rule (lower_swiden_low $I32X4 val)
(x64_psrad (x64_punpcklwd val val) (xmi_imm 16)))
;; Generate the sign-extended halves with a `val < 0` comparison (expressed
;; reversed here), then interleave the low 32-bit halves to create the full
;; 64-bit results.
(rule (lower_swiden_low $I64X2 val)
(let ((tmp Xmm (x64_pcmpgtd (xmm_zero $I32X4) val)))
(x64_punpckldq val tmp)))
;; Rules for `swiden_high` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Similar to `swiden_low` with SSE4.1 except that the upper lanes are moved
;; to the lower lanes first.
(rule 1 (lower (has_type $I16X8 (swiden_high val @ (value_type $I8X16))))
(if-let $true (use_sse41))
(if-let $true (use_ssse3))
(let ((x Xmm val))
(x64_pmovsxbw (x64_palignr x x 8))))
(rule 1 (lower (has_type $I32X4 (swiden_high val @ (value_type $I16X8))))
(if-let $true (use_sse41))
(if-let $true (use_ssse3))
(let ((x Xmm val))
(x64_pmovsxwd (x64_palignr x x 8))))
(rule 1 (lower (has_type $I64X2 (swiden_high val @ (value_type $I32X4))))
(if-let $true (use_sse41))
(x64_pmovsxdq (x64_pshufd val 0b11_10_11_10)))
;; Similar to `swiden_low` versions but using `punpckh*` instructions to
;; pair the high lanes next to each other.
(rule (lower (has_type $I16X8 (swiden_high val @ (value_type $I8X16))))
(let ((val Xmm val))
(x64_psraw (x64_punpckhbw val val) (xmi_imm 8))))
(rule (lower (has_type $I32X4 (swiden_high val @ (value_type $I16X8))))
(let ((val Xmm val))
(x64_psrad (x64_punpckhwd val val) (xmi_imm 16))))
;; Same as `swiden_low`, but `val` has its high lanes moved down.
(rule (lower (has_type $I64X2 (swiden_high val @ (value_type $I32X4))))
(let ((val Xmm (x64_pshufd val 0b00_00_11_10))
(tmp Xmm (x64_pcmpgtd (xmm_zero $I32X4) val)))
(x64_punpckldq val tmp)))
;; Rules for `uwiden_low` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; With SSE4.1 use the `pmovzx*` instructions for this
(rule 1 (lower (has_type $I16X8 (uwiden_low val @ (value_type $I8X16))))
(if-let $true (use_sse41))
(x64_pmovzxbw val))
(rule 1 (lower (has_type $I32X4 (uwiden_low val @ (value_type $I16X8))))
(if-let $true (use_sse41))
(x64_pmovzxwd val))
(rule 1 (lower (has_type $I64X2 (uwiden_low val @ (value_type $I32X4))))
(if-let $true (use_sse41))
(x64_pmovzxdq val))
(rule (lower (has_type ty (uwiden_low val))) (lower_uwiden_low ty val))
;; Interleave an all-zero register with the low lanes to produce zero-extended
;; results.
(decl lower_uwiden_low (Type Xmm) Xmm)
(rule (lower_uwiden_low $I16X8 val) (x64_punpcklbw val (xmm_zero $I8X16)))
(rule (lower_uwiden_low $I32X4 val) (x64_punpcklwd val (xmm_zero $I8X16)))
(rule (lower_uwiden_low $I64X2 val) (x64_unpcklps val (xmm_zero $F32X4)))
;; Rules for `uwiden_high` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Same as `uwiden_high`, but interleaving high lanes instead.
;;
;; Note that according to `llvm-mca` at least these instructions are faster
;; than using `pmovzx*` in terms of cycles, even if SSE4.1 is available.
(rule (lower (has_type $I16X8 (uwiden_high val @ (value_type $I8X16))))
(x64_punpckhbw val (xmm_zero $I8X16)))
(rule (lower (has_type $I32X4 (uwiden_high val @ (value_type $I16X8))))
(x64_punpckhwd val (xmm_zero $I8X16)))
(rule (lower (has_type $I64X2 (uwiden_high val @ (value_type $I32X4))))
(x64_unpckhps val (xmm_zero $F32X4)))
;; Rules for `snarrow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16 (snarrow a @ (value_type $I16X8) b)))
(x64_packsswb a b))
(rule (lower (has_type $I16X8 (snarrow a @ (value_type $I32X4) b)))
(x64_packssdw a b))
;; We're missing a `snarrow` case for $I64X2
;; https://github.com/bytecodealliance/wasmtime/issues/4734
;; This rule is a special case for handling the translation of the wasm op
;; `i32x4.trunc_sat_f64x2_s_zero`. It can be removed once we have an
;; implementation of `snarrow` for `I64X2`.
(rule (lower (has_type $I32X4 (snarrow (has_type $I64X2 (fcvt_to_sint_sat val))
(vconst (u128_from_constant 0)))))
(let ((a Xmm val)
;; y = i32x4.trunc_sat_f64x2_s_zero(x) is lowered to:
;; MOVE xmm_tmp, xmm_x
;; CMPEQPD xmm_tmp, xmm_x
;; MOVE xmm_y, xmm_x
;; ANDPS xmm_tmp, [wasm_f64x2_splat(2147483647.0)]
;; MINPD xmm_y, xmm_tmp
;; CVTTPD2DQ xmm_y, xmm_y
(tmp1 Xmm (x64_cmppd a a (FcmpImm.Equal)))
;; 2147483647.0 is equivalent to 0x41DFFFFFFFC00000
(umax_mask XmmMem (emit_u128_le_const 0x41DFFFFFFFC00000_41DFFFFFFFC00000))
;; ANDPD xmm_y, [wasm_f64x2_splat(2147483647.0)]
(tmp1 Xmm (x64_andps tmp1 umax_mask))
(dst Xmm (x64_minpd a tmp1)))
(x64_cvttpd2dq dst)))
;; This rule is a special case for handling the translation of the wasm op
;; `i32x4.relaxed_trunc_f64x2_s_zero`.
(rule (lower (has_type $I32X4 (snarrow (has_type $I64X2 (x86_cvtt2dq val))
(vconst (u128_from_constant 0)))))
(x64_cvttpd2dq val))
;; Rules for `unarrow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I8X16 (unarrow a @ (value_type $I16X8) b)))
(x64_packuswb a b))
(rule 1 (lower (has_type $I16X8 (unarrow a @ (value_type $I32X4) b)))
(if-let $true (use_sse41))
(x64_packusdw a b))
;; For each input `a` and `b` take the four 32-bit lanes and compress them to
;; the low 64-bits of the vector as four 16-bit lanes. Then these are woven
;; into one final vector with a `punpcklqdq`.
;;
;; If this is performance sensitive then it's probably best to upgrade the CPU
;; to get the above single-instruction lowering.
(rule (lower (has_type $I16X8 (unarrow a @ (value_type $I32X4) b)))
(let (
(a Xmm (unarrow_i32x4_lanes_to_low_u16_lanes a))
(b Xmm (unarrow_i32x4_lanes_to_low_u16_lanes b))
)
(x64_punpcklqdq a b)))
(decl unarrow_i32x4_lanes_to_low_u16_lanes (Xmm) Xmm)
(rule (unarrow_i32x4_lanes_to_low_u16_lanes val)
(let (
;; First convert all negative values in `val` to zero lanes.
(val_gt_zero Xmm (x64_pcmpgtd val (xmm_zero $I32X4)))
(val Xmm (x64_pand val val_gt_zero))
;; Next clamp all larger-than-u16-max lanes to u16::MAX.
(max Xmm (x64_movdqu_load (emit_u128_le_const 0x0000ffff_0000ffff_0000ffff_0000ffff)))
(cmp Xmm (x64_pcmpgtd max val))
(valid_lanes Xmm (x64_pand val cmp))
(clamped_lanes Xmm (x64_pandn cmp max))
(val Xmm (x64_por valid_lanes clamped_lanes))
;; Within each 64-bit half of the 32x4 vector move the first 16 bits
;; and the third 16 bits to the bottom of the half. Afterwards
;; for the 32x4 vector move the first and third lanes to the bottom
;; lanes, which finishes up the conversion here as all the lanes
;; are now converted to 16-bit values in the low 4 lanes.
(val Xmm (x64_pshuflw val 0b00_00_10_00))
(val Xmm (x64_pshufhw val 0b00_00_10_00))
)
(x64_pshufd val 0b00_00_10_00)))
;; We're missing a `unarrow` case for $I64X2
;; https://github.com/bytecodealliance/wasmtime/issues/4734
;; Rules for `bitcast` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $I32 (bitcast _ src @ (value_type $F32))))
(bitcast_xmm_to_gpr $F32 src))
(rule (lower (has_type $F32 (bitcast _ src @ (value_type $I32))))
(bitcast_gpr_to_xmm $I32 src))
(rule (lower (has_type $I64 (bitcast _ src @ (value_type $F64))))
(bitcast_xmm_to_gpr $F64 src))
(rule (lower (has_type $F64 (bitcast _ src @ (value_type $I64))))
(bitcast_gpr_to_xmm $I64 src))
;; Bitcast between types residing in GPR registers is a no-op.
(rule 1 (lower (has_type (is_gpr_type _)
(bitcast _ x @ (value_type (is_gpr_type _))))) x)
;; Bitcast between types residing in XMM registers is a no-op.
(rule 2 (lower (has_type (is_xmm_type _)
(bitcast _ x @ (value_type (is_xmm_type _))))) x)
;; Rules for `fcopysign` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type $F32 (fcopysign a @ (value_type $F32) b)))
(let ((sign_bit Xmm (imm $F32 0x80000000)))
(x64_orps
(x64_andnps sign_bit a)
(x64_andps sign_bit b))))
(rule (lower (has_type $F64 (fcopysign a @ (value_type $F64) b)))
(let ((sign_bit Xmm (imm $F64 0x8000000000000000)))
(x64_orpd
(x64_andnpd sign_bit a)
(x64_andpd sign_bit b))))
;; Helper for the `ceil`/`floor`/`nearest`/`trunc` instructions ;;;;;;;;;;;;;;;;
;; Emits either a `round{ss,sd,ps,pd}` instruction, as appropriate, or generates
;; the appropriate libcall and sequence to call that.
(decl x64_round (Type RegMem RoundImm) Xmm)
(rule 1 (x64_round $F32 a imm)
(if-let $true (use_sse41))
(x64_roundss a imm))
(rule 1 (x64_round $F64 a imm)
(if-let $true (use_sse41))
(x64_roundsd a imm))
(rule 1 (x64_round $F32X4 a imm)
(if-let $true (use_sse41))
(x64_roundps a imm))
(rule 1 (x64_round $F64X2 a imm)
(if-let $true (use_sse41))
(x64_roundpd a imm))
(rule (x64_round $F32 (RegMem.Reg a) imm) (libcall_1 (round_libcall $F32 imm) a))
(rule (x64_round $F64 (RegMem.Reg a) imm) (libcall_1 (round_libcall $F64 imm) a))
(rule (x64_round $F32X4 (RegMem.Reg a) imm)
(let (
(libcall LibCall (round_libcall $F32 imm))
(result Xmm (libcall_1 libcall a))
(a1 Xmm (libcall_1 libcall (x64_pshufd a 1)))
(result Xmm (vec_insert_lane $F32X4 result a1 1))
(a2 Xmm (libcall_1 libcall (x64_pshufd a 2)))
(result Xmm (vec_insert_lane $F32X4 result a2 2))
(a3 Xmm (libcall_1 libcall (x64_pshufd a 3)))
(result Xmm (vec_insert_lane $F32X4 result a3 3))
)
result))
(rule (x64_round $F64X2 (RegMem.Reg a) imm)
(let (
(libcall LibCall (round_libcall $F64 imm))
(result Xmm (libcall_1 libcall a))
(a1 Xmm (libcall_1 libcall (x64_pshufd a 0b00_00_11_10)))
(result Xmm (vec_insert_lane $F64X2 result a1 1))
)
result))
(rule (x64_round ty (RegMem.Mem addr) imm)
(x64_round ty (RegMem.Reg (x64_load ty addr (ExtKind.ZeroExtend))) imm))
(decl round_libcall (Type RoundImm) LibCall)
(rule (round_libcall $F32 (RoundImm.RoundUp)) (LibCall.CeilF32))
(rule (round_libcall $F64 (RoundImm.RoundUp)) (LibCall.CeilF64))
(rule (round_libcall $F32 (RoundImm.RoundDown)) (LibCall.FloorF32))
(rule (round_libcall $F64 (RoundImm.RoundDown)) (LibCall.FloorF64))
(rule (round_libcall $F32 (RoundImm.RoundNearest)) (LibCall.NearestF32))
(rule (round_libcall $F64 (RoundImm.RoundNearest)) (LibCall.NearestF64))
(rule (round_libcall $F32 (RoundImm.RoundZero)) (LibCall.TruncF32))
(rule (round_libcall $F64 (RoundImm.RoundZero)) (LibCall.TruncF64))
;; Rules for `ceil` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (ceil a @ (value_type ty)))
(x64_round ty a (RoundImm.RoundUp)))
;; Rules for `floor` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (floor a @ (value_type ty)))
(x64_round ty a (RoundImm.RoundDown)))
;; Rules for `nearest` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (nearest a @ (value_type ty)))
(x64_round ty a (RoundImm.RoundNearest)))
;; Rules for `trunc` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (trunc a @ (value_type ty)))
(x64_round ty a (RoundImm.RoundZero)))
;; Rules for `stack_addr` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (stack_addr stack_slot offset))
(stack_addr_impl stack_slot offset))
;; Rules for `udiv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; NB: a `RegMem` divisor, while allowed in the instruction encoding, isn't
;; used right now to prevent a possibly-trapping load getting folded into the
;; `div` instruction. Ideally non-trapping loads would get folded, however, or
;; alternatively Wasmtime/Cranelift would grow support for multiple traps on
;; a single opcode and the signal kind would differentiate at runtime.
;; The inputs to the `div` instruction are different for 8-bit division so
;; it needs a special case here since the instruction being crafted has a
;; different shape.
(rule 2 (lower (udiv a @ (value_type $I8) b))
(x64_div8 (extend_to_gpr a $I32 (ExtendKind.Zero))
(put_in_gpr b)
(DivSignedness.Unsigned)
(TrapCode.IntegerDivisionByZero)))
;; 16-to-64-bit division is all done with a similar instruction and the only
;; tricky requirement here is that when div traps are disallowed the divisor
;; must not be zero.
(rule 1 (lower (udiv a @ (value_type (fits_in_64 ty)) b))
(x64_div_quotient a
(imm $I64 0)
(put_in_gpr b)
(raw_operand_size_of_type ty)
(DivSignedness.Unsigned)
(TrapCode.IntegerDivisionByZero)))
;; Rules for `sdiv` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 2 (lower (sdiv a @ (value_type $I8) b))
(x64_div8 (x64_sign_extend_data a (OperandSize.Size8))
(nonzero_sdiv_divisor $I8 b)
(DivSignedness.Signed)
(TrapCode.IntegerOverflow)))
(rule 1 (lower (sdiv a @ (value_type (fits_in_64 ty)) b))
(let (
(a Gpr a)
(size OperandSize (raw_operand_size_of_type ty))
)
(x64_div_quotient a
(x64_sign_extend_data a size)
(nonzero_sdiv_divisor ty b)
size
(DivSignedness.Signed)
(TrapCode.IntegerOverflow))))
;; Checks to make sure that the input `Value` is a non-zero value for `sdiv`.
;;
;; This is required to differentiate the divide-by-zero trap from the
;; integer-overflow trap, the two trapping conditions of signed division.
(decl nonzero_sdiv_divisor (Type Value) Reg)
(rule 1 (nonzero_sdiv_divisor ty (iconst imm))
(if-let n (safe_divisor_from_imm64 ty imm))
(imm ty n))
(rule 0 (nonzero_sdiv_divisor ty val)
(let (
(val Reg val)
(_ InstOutput (side_effect (with_flags_side_effect
(x64_test (raw_operand_size_of_type ty) val val)
(trap_if (CC.Z) (TrapCode.IntegerDivisionByZero)))))
)
val))
;; Rules for `urem` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The remainder is in AH, so take the result of the division and right-shift
;; by 8.
(rule 2 (lower (urem a @ (value_type $I8) b))
(let (
(result Gpr (x64_div8 (extend_to_gpr a $I32 (ExtendKind.Zero))
(put_in_gpr b) ;; see `udiv` for why not `gpr_mem`
(DivSignedness.Unsigned)
(TrapCode.IntegerDivisionByZero)))
)
(x64_shr $I64 result (Imm8Reg.Imm8 8))))
(rule 1 (lower (urem a @ (value_type (fits_in_64 ty)) b))
(x64_div_remainder a
(imm $I64 0)
(put_in_gpr b) ;; see `udiv` for why not `gpr_mem`
(raw_operand_size_of_type ty)
(DivSignedness.Unsigned)
(TrapCode.IntegerDivisionByZero)))
;; Rules for `srem` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Special-cases first for constant `srem` where the checks for 0 and -1 aren't
;; applicable.
;;
;; Note that like `urem` for i8 types the result is in AH so to get the result
;; it's right-shifted down.
(rule 3 (lower (srem a @ (value_type $I8) (iconst imm)))
(if-let n (safe_divisor_from_imm64 $I8 imm))
(let (
(a Gpr (x64_sign_extend_data a (OperandSize.Size8)))
(result Gpr (x64_div8 a (imm $I8 n) (DivSignedness.Signed) (TrapCode.IntegerDivisionByZero)))
)
(x64_shr $I64 result (Imm8Reg.Imm8 8))))
;; Same as the above rule but for 16-to-64 bit types.
(rule 2 (lower (srem a @ (value_type ty) (iconst imm)))
(if-let n (safe_divisor_from_imm64 ty imm))
(let (
(a Gpr a)
(size OperandSize (raw_operand_size_of_type ty))
)
(x64_div_remainder a
(x64_sign_extend_data a size)
(imm ty n)
size
(DivSignedness.Signed)
(TrapCode.IntegerDivisionByZero))))
(rule 1 (lower (srem a @ (value_type $I8) b))
(let (
(a Gpr (x64_sign_extend_data a (OperandSize.Size8)))
)
(x64_shr $I64 (x64_checked_srem_seq8 a b) (Imm8Reg.Imm8 8))))
(rule (lower (srem a @ (value_type ty) b))
(let (
(a Gpr a)
(size OperandSize (raw_operand_size_of_type ty))
(hi Gpr (x64_sign_extend_data a size))
(tmp ValueRegs (x64_checked_srem_seq size a hi b))
)
(value_regs_get tmp 1)))
;; Rules for `umulhi` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (umulhi a @ (value_type $I16) b))
(let ((res ValueRegs (mul_hi $I16 $false a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (umulhi a @ (value_type $I32) b))
(let ((res ValueRegs (mul_hi $I32 $false a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (umulhi a @ (value_type $I64) b))
(let ((res ValueRegs (mul_hi $I64 $false a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
;; Rules for `smulhi` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (smulhi a @ (value_type $I16) b))
(let ((res ValueRegs (mul_hi $I16 $true a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (smulhi a @ (value_type $I32) b))
(let ((res ValueRegs (mul_hi $I32 $true a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
(rule (lower (smulhi a @ (value_type $I64) b))
(let ((res ValueRegs (mul_hi $I64 $true a b))
(hi Gpr (value_regs_get_gpr res 1)))
hi))
;; Rules for `get_pinned_reg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (get_pinned_reg))
(read_pinned_gpr))
;; Rules for `set_pinned_reg` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (set_pinned_reg a @ (value_type ty)))
(side_effect (write_pinned_gpr a)))
;; Rules for `vconst` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type ty (vconst const)))
;; TODO use Inst::gen_constant() instead.
(x64_xmm_load_const ty (const_to_vconst const)))
;; Rules for `shuffle` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Special case for `pblendw` which takes an 8-bit immediate where each bit
;; indicates which lane of the two operands is chosen for the output. A bit of
;; 0 chooses the corresponding 16-it lane from `a` and a bit of 1 chooses the
;; corresponding 16-bit lane from `b`.
(rule 14 (lower (shuffle a b (pblendw_imm n)))
(if-let $true (use_sse41))
(x64_pblendw a b n))
(decl pblendw_imm (u8) Immediate)
(extern extractor pblendw_imm pblendw_imm)
;; When the shuffle looks like "concatenate `a` and `b` and shift right by n*8
;; bytes", that's a `palignr` instruction. Note that the order of operands are
;; swapped in the instruction here. The `palignr` instruction uses the second
;; operand as the low-order bytes and the first operand as high-order bytes,
;; so put `a` second.
(rule 13 (lower (shuffle a b (palignr_imm_from_immediate n)))
(if-let $true (use_ssse3))
(x64_palignr b a n))
(decl palignr_imm_from_immediate (u8) Immediate)
(extern extractor palignr_imm_from_immediate palignr_imm_from_immediate)
;; Special case the `pshuf{l,h}w` instruction which shuffles four 16-bit
;; integers within one value, preserving the other four 16-bit integers in that
;; value (either the high or low half). The complicated logic is in the
;; extractors here implemented in Rust and note that there's two cases for each
;; instruction here to match when either the first or second shuffle operand is
;; used.
(rule 12 (lower (shuffle x y (pshuflw_lhs_imm imm)))
(x64_pshuflw x imm))
(rule 11 (lower (shuffle x y (pshuflw_rhs_imm imm)))
(x64_pshuflw y imm))
(rule 10 (lower (shuffle x y (pshufhw_lhs_imm imm)))
(x64_pshufhw x imm))
(rule 9 (lower (shuffle x y (pshufhw_rhs_imm imm)))
(x64_pshufhw y imm))
(decl pshuflw_lhs_imm (u8) Immediate)
(extern extractor pshuflw_lhs_imm pshuflw_lhs_imm)
(decl pshuflw_rhs_imm (u8) Immediate)
(extern extractor pshuflw_rhs_imm pshuflw_rhs_imm)
(decl pshufhw_lhs_imm (u8) Immediate)
(extern extractor pshufhw_lhs_imm pshufhw_lhs_imm)
(decl pshufhw_rhs_imm (u8) Immediate)
(extern extractor pshufhw_rhs_imm pshufhw_rhs_imm)
;; Special case for the `pshufd` instruction which will permute 32-bit values
;; within a single register. This is only applicable if the `imm` specified
;; selects 32-bit values from either `x` or `y`, but not both. This means
;; there's one rule for selecting from `x` and another rule for selecting from
;; `y`.
(rule 8 (lower (shuffle x y (pshufd_lhs_imm imm)))
(x64_pshufd x imm))
(rule 7 (lower (shuffle x y (pshufd_rhs_imm imm)))
(x64_pshufd y imm))
(decl pshufd_lhs_imm (u8) Immediate)
(extern extractor pshufd_lhs_imm pshufd_lhs_imm)
(decl pshufd_rhs_imm (u8) Immediate)
(extern extractor pshufd_rhs_imm pshufd_rhs_imm)
;; Special case for i8-level interleaving of upper/low bytes.
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1f0f_1e0e_1d0d_1c0c_1b0b_1a0a_1909_1808)))
(x64_punpckhbw a b))
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1707_1606_1505_1404_1303_1202_1101_1000)))
(x64_punpcklbw a b))
;; Special case for i16-level interleaving of upper/low bytes.
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1f1e_0f0e_1d1c_0d0c_1b1a_0b0a_1918_0908)))
(x64_punpckhwd a b))
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1716_0706_1514_0504_1312_0302_1110_0100)))
(x64_punpcklwd a b))
;; Special case for i32-level interleaving of upper/low bytes.
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1f1e1d1c_0f0e0d0c_1b1a1918_0b0a0908)))
(x64_punpckhdq a b))
(rule 6 (lower (shuffle a b (u128_from_immediate 0x17161514_07060504_13121110_03020100)))
(x64_punpckldq a b))
;; Special case for i64-level interleaving of upper/low bytes.
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1f1e1d1c1b1a1918_0f0e0d0c0b0a0908)))
(x64_punpckhqdq a b))
(rule 6 (lower (shuffle a b (u128_from_immediate 0x1716151413121110_0706050403020100)))
(x64_punpcklqdq a b))
;; If the vector shift mask is all 0s then that means the first byte of the
;; first operand is broadcast to all bytes. Falling through would load an
;; all-zeros constant from a rip-relative location but it should be slightly
;; more efficient to execute the `pshufb` here-and-now with an xor'd-to-be-zero
;; register.
(rule 6 (lower (shuffle a _ (u128_from_immediate 0)))
(if-let $true (use_ssse3))
(x64_pshufb a (xmm_zero $I8X16)))
;; Special case for the `shufps` instruction which will select two 32-bit values
;; from the first operand and two 32-bit values from the second operand. Note
;; that there is a second case here as well for when the operands can be
;; swapped.
;;
;; Note that the priority of this instruction is currently lower than the above
;; special cases since `shufps` handles many of them and for now it's
;; hypothesized that the dedicated instructions are better than `shufps`.
;; Someone with more knowledge about x86 timings should perhaps reorder the
;; rules here eventually though.
(rule 5 (lower (shuffle x y (shufps_imm imm)))
(x64_shufps x y imm))
(rule 4 (lower (shuffle x y (shufps_rev_imm imm)))
(x64_shufps y x imm))
(decl shufps_imm(u8) Immediate)
(extern extractor shufps_imm shufps_imm)
(decl shufps_rev_imm(u8) Immediate)
(extern extractor shufps_rev_imm shufps_rev_imm)
;; If `lhs` and `rhs` are the same we can use a single PSHUFB to shuffle the XMM
;; register. We statically build `constructed_mask` to zero out any unknown lane
;; indices (may not be completely necessary: verification could fail incorrect
;; mask values) and fix the indexes to all point to the `dst` vector.
(rule 3 (lower (shuffle a a (vec_mask_from_immediate mask)))
(if-let $true (use_ssse3))
(x64_pshufb a (shuffle_0_31_mask mask)))
;; For the case where the shuffle mask contains out-of-bounds values (values
;; greater than 31) we must mask off those resulting values in the result of
;; `vpermi2b`.
(rule 2 (lower (shuffle a b (vec_mask_from_immediate (perm_from_mask_with_zeros mask zeros))))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512vbmi))
(x64_andps (x64_vpermi2b (x64_xmm_load_const $I8X16 mask) a b) zeros))
;; However, if the shuffle mask contains no out-of-bounds values, we can use
;; `vpermi2b` without any masking.
(rule 1 (lower (shuffle a b (vec_mask_from_immediate mask)))
(if-let $true (use_avx512vl))
(if-let $true (use_avx512vbmi))
(x64_vpermi2b (x64_xmm_load_const $I8X16 (perm_from_mask mask)) a b))
;; If `lhs` and `rhs` are different, we must shuffle each separately and then OR
;; them together. This is necessary due to PSHUFB semantics. As in the case
;; above, we build the `constructed_mask` for each case statically.
(rule (lower (shuffle a b (vec_mask_from_immediate mask)))
(x64_por
(lower_pshufb a (shuffle_0_15_mask mask))
(lower_pshufb b (shuffle_16_31_mask mask))))
;; Rules for `swizzle` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; SIMD swizzle; the following inefficient implementation is due to the Wasm
;; SIMD spec requiring mask indexes greater than 15 to have the same semantics
;; as a 0 index. For the spec discussion, see
;; https://github.com/WebAssembly/simd/issues/93. The CLIF semantics match the
;; Wasm SIMD semantics for this instruction. The instruction format maps to
;; variables like: %dst = swizzle %src, %mask
(rule (lower (swizzle src mask))
(let ((mask Xmm (x64_paddusb mask (emit_u128_le_const 0x70707070707070707070707070707070))))
(lower_pshufb src mask)))
;; Rules for `x86_pshufb` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (x86_pshufb src mask))
(if-let $true (use_ssse3))
(x64_pshufb src mask))
;; A helper function to generate either the `pshufb` instruction or a libcall to
;; the `X86Pshufb` libcall. Note that the libcall is not exactly the most
;; performant thing in the world so this is primarily here for completeness
;; of lowerings on all x86 cpus but if rules are ideally gated on the presence
;; of SSSE3 to use the `pshufb` instruction itself.
(decl lower_pshufb (Xmm RegMem) Xmm)
(rule 1 (lower_pshufb src mask)
(if-let $true (use_ssse3))
(x64_pshufb src mask))
(rule (lower_pshufb src (RegMem.Reg mask))
(libcall_2 (LibCall.X86Pshufb) src mask))
(rule (lower_pshufb src (RegMem.Mem addr))
(lower_pshufb src (x64_movdqu_load addr)))
;; Rules for `extractlane` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Remove the extractlane instruction, leaving the float where it is. The upper
;; bits will remain unchanged; for correctness, this relies on Cranelift type
;; checking to avoid using those bits.
(rule 3 (lower (has_type (ty_scalar_float _) (extractlane val 0)))
val)
;; `f32x4.extract_lane N` where `N != 0`
(rule 1 (lower (extractlane val @ (value_type $F32X4) (u8_from_uimm8 lane)))
(x64_pshufd val lane))
;; `f64x2.extract_lane N` where `N != 0` (aka N == 1)
(rule (lower (extractlane val @ (value_type $F64X2) 1))
(x64_pshufd val 0b11_10_11_10))
;; `i8x16.extract_lane N`
;;
;; Note that without SSE4.1 a 16-bit lane extraction is performed and then
;; the result is updated if the desired index is either odd or even.
(rule 2 (lower (extractlane val @ (value_type ty @ $I8X16) (u8_from_uimm8 lane)))
(if-let $true (use_sse41))
(x64_pextrb val lane))
;; extracting an odd lane has an extra shift-right
(rule 1 (lower (extractlane val @ (value_type ty @ $I8X16) (u8_from_uimm8 lane)))
(if-let 1 (u8_and lane 1))
(x64_shr $I16 (x64_pextrw val (u8_shr lane 1)) (Imm8Reg.Imm8 8)))
;; Extracting an even lane already has the desired lane in the lower bits. Note
;; that having arbitrary upper bits in the returned register should be ok since
;; all operators on the resulting `i8` type should work correctly regardless of
;; the bits in the rest of the register.
(rule (lower (extractlane val @ (value_type ty @ $I8X16) (u8_from_uimm8 lane)))
(if-let 0 (u8_and lane 1))
(x64_pextrw val (u8_shr lane 1)))
;; `i16x8.extract_lane N`
(rule (lower (extractlane val @ (value_type ty @ $I16X8) (u8_from_uimm8 lane)))
(x64_pextrw val lane))
;; `i32x4.extract_lane N`
(rule 2 (lower (extractlane val @ (value_type ty @ $I32X4) (u8_from_uimm8 lane)))
(if-let $true (use_sse41))
(x64_pextrd val lane))
(rule 1 (lower (extractlane val @ (value_type $I32X4) 0))
(x64_movd_to_gpr val))
(rule (lower (extractlane val @ (value_type $I32X4) (u8_from_uimm8 n)))
(x64_movd_to_gpr (x64_pshufd val n)))
;; `i64x2.extract_lane N`
(rule 1 (lower (extractlane val @ (value_type $I64X2) (u8_from_uimm8 lane)))
(if-let $true (use_sse41))
(x64_pextrq val lane))
(rule (lower (extractlane val @ (value_type $I64X2) 0))
(x64_movq_to_gpr val))
(rule (lower (extractlane val @ (value_type $I64X2) 1))
(x64_movq_to_gpr (x64_pshufd val 0b00_00_11_10)))
;; Rules for `scalar_to_vector` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Case 1: when moving a scalar float, we simply move from one XMM register
;; to another, expecting the register allocator to elide this. Here we
;; assume that the upper bits of a scalar float have not been munged with
;; (the same assumption the old backend makes).
(rule 1 (lower (scalar_to_vector src @ (value_type (ty_scalar_float _))))
src)
;; Case 2: when moving a scalar value of any other type, use MOVD to zero
;; the upper lanes.
(rule (lower (scalar_to_vector src @ (value_type ty)))
(bitcast_gpr_to_xmm ty src))
;; Case 3: when presented with `load + scalar_to_vector`, coalesce into a single
;; MOVSS/MOVSD instruction.
(rule 2 (lower (scalar_to_vector (and (sinkable_load src) (value_type (ty_32 _)))))
(x64_movss_load src))
(rule 3 (lower (scalar_to_vector (and (sinkable_load src) (value_type (ty_64 _)))))
(x64_movsd_load src))
;; Rules for `splat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; For all the splat rules below one of the goals is that splatting a value
;; doesn't end up accidentally depending on the previous value in a register.
;; This means that instructions are chosen to avoid false dependencies where
;; new values are created fresh or otherwise overwrite previous register
;; contents where possible.
;;
;; Additionally splats are specialized to special-case load-and-splat which
;; has a number of micro-optimizations available.
;; i8x16 splats: use `vpbroadcastb` on AVX2 and otherwise `pshufb` broadcasts
;; with a mask of zero which is calculated with an xor-against-itself register.
(rule 0 (lower (has_type $I8X16 (splat src)))
(let ((src Xmm (x64_movd_to_xmm src)))
(x64_pshufd (x64_pshuflw (x64_punpcklbw src src) 0) 0)))
(rule 1 (lower (has_type $I8X16 (splat src)))
(if-let $true (use_ssse3))
(x64_pshufb (bitcast_gpr_to_xmm $I32 src) (xmm_zero $I8X16)))
(rule 2 (lower (has_type $I8X16 (splat src)))
(if-let $true (use_avx2))
(x64_vpbroadcastb (bitcast_gpr_to_xmm $I32 src)))
(rule 3 (lower (has_type $I8X16 (splat (sinkable_load_exact addr))))
(if-let $true (use_sse41))
(if-let $true (use_ssse3))
(x64_pshufb (x64_pinsrb (xmm_uninit_value) addr 0) (xmm_zero $I8X16)))
(rule 4 (lower (has_type $I8X16 (splat (sinkable_load_exact addr))))
(if-let $true (use_avx2))
(x64_vpbroadcastb addr))
;; i16x8 splats: use `vpbroadcastw` on AVX2 and otherwise a 16-bit value is
;; loaded into an xmm register, `pshuflw` broadcasts the low 16-bit lane
;; to the low four lanes, and `pshufd` broadcasts the low 32-bit lane (which
;; at that point is two of the 16-bit values we want to broadcast) to all the
;; lanes.
(rule 0 (lower (has_type $I16X8 (splat src)))
(x64_pshufd (x64_pshuflw (bitcast_gpr_to_xmm $I32 src) 0) 0))
(rule 1 (lower (has_type $I16X8 (splat src)))
(if-let $true (use_avx2))
(x64_vpbroadcastw (bitcast_gpr_to_xmm $I32 src)))
(rule 2 (lower (has_type $I16X8 (splat (sinkable_load_exact addr))))
(x64_pshufd (x64_pshuflw (x64_pinsrw (xmm_uninit_value) addr 0) 0) 0))
(rule 3 (lower (has_type $I16X8 (splat (sinkable_load_exact addr))))
(if-let $true (use_avx2))
(x64_vpbroadcastw addr))
;; i32x4.splat - use `vpbroadcastd` on AVX2 and otherwise `pshufd` can be
;; used to broadcast the low lane to all other lanes.
;;
;; Note that sinkable-load cases come later
(rule 0 (lower (has_type $I32X4 (splat src)))
(x64_pshufd (bitcast_gpr_to_xmm $I32 src) 0))
(rule 1 (lower (has_type $I32X4 (splat src)))
(if-let $true (use_avx2))
(x64_vpbroadcastd (bitcast_gpr_to_xmm $I32 src)))
;; f32x4.splat - the source is already in an xmm register so `shufps` is all
;; that's necessary to complete the splat. This is specialized to `vbroadcastss`
;; on AVX2 to leverage that specific instruction for this operation.
(rule 0 (lower (has_type $F32X4 (splat src)))
(let ((tmp Xmm src))
(x64_shufps src src 0)))
(rule 1 (lower (has_type $F32X4 (splat src)))
(if-let $true (use_avx2))
(x64_vbroadcastss src))
;; t32x4.splat of a load - use a `movss` to load into an xmm register and then
;; `shufps` broadcasts to the other lanes. Note that this is used for both i32
;; and f32 splats.
;;
;; With AVX the `vbroadcastss` instruction suits this purpose precisely. Note
;; that the memory-operand encoding of `vbroadcastss` is usable with AVX, but
;; the register-based encoding is only available with AVX2. With the
;; `sinkable_load` extractor this should be guaranteed to use the memory-based
;; encoding hence the `use_avx` test.
(rule 5 (lower (has_type (multi_lane 32 4) (splat (sinkable_load addr))))
(let ((tmp Xmm (x64_movss_load addr)))
(x64_shufps tmp tmp 0)))
(rule 6 (lower (has_type (multi_lane 32 4) (splat (sinkable_load addr))))
(if-let $true (use_avx))
(x64_vbroadcastss addr))
;; t64x2.splat - use `pshufd` to broadcast the lower 64-bit lane to the upper
;; lane. A minor specialization for sinkable loads to avoid going through a gpr
;; for i64 splats is used as well when `movddup` is available.
(rule 0 (lower (has_type $I64X2 (splat src)))
(x64_pshufd (bitcast_gpr_to_xmm $I64 src) 0b01_00_01_00))
(rule 0 (lower (has_type $F64X2 (splat src)))
(x64_pshufd src 0b01_00_01_00))
(rule 6 (lower (has_type (multi_lane 64 2) (splat (sinkable_load addr))))
(if-let $true (use_ssse3))
(x64_movddup addr))
;; Rules for `vany_true` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (vany_true val))
(if-let $true (use_sse41))
(let ((val Xmm val))
(with_flags (x64_ptest val val) (x64_setcc (CC.NZ)))))
;; Any nonzero byte in `val` means that any lane is true. Compare `val` with a
;; zeroed register and extract the high bits to a gpr mask. If the mask is
;; 0xffff then every byte was equal to zero, so test if the comparison is
;; not-equal or NZ.
(rule (lower (vany_true val))
(let (
(any_byte_zero Xmm (x64_pcmpeqb val (xmm_zero $I8X16)))
(mask Gpr (x64_pmovmskb (OperandSize.Size32) any_byte_zero))
)
(with_flags (x64_cmp (OperandSize.Size32) (RegMemImm.Imm 0xffff) mask)
(x64_setcc (CC.NZ)))))
;; Rules for `vall_true` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (vall_true val @ (value_type ty)))
(if-let $true (use_sse41))
(let ((src Xmm val)
(zeros Xmm (xmm_zero ty))
(cmp Xmm (x64_pcmpeq (vec_int_type ty) src zeros)))
(with_flags (x64_ptest cmp cmp) (x64_setcc (CC.Z)))))
;; Perform an appropriately-sized lane-wise comparison with zero. If the
;; result is all 0s then all of them are true because nothing was equal to
;; zero.
(rule (lower (vall_true val @ (value_type ty)))
(let ((lanes_with_zero Xmm (x64_pcmpeq (vec_int_type ty) val (xmm_zero ty)))
(mask Gpr (x64_pmovmskb (OperandSize.Size32) lanes_with_zero)))
(with_flags (x64_test (OperandSize.Size32) mask mask)
(x64_setcc (CC.Z)))))
;; Rules for `vhigh_bits` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; The Intel specification allows using both 32-bit and 64-bit GPRs as
;; destination for the "move mask" instructions. This is controlled by the REX.R
;; bit: "In 64-bit mode, the instruction can access additional registers when
;; used with a REX.R prefix. The default operand size is 64-bit in 64-bit mode"
;; (PMOVMSKB in IA Software Development Manual, vol. 2). This being the case, we
;; will always clear REX.W since its use is unnecessary (`OperandSize` is used
;; for setting/clearing REX.W) as we need at most 16 bits of output for
;; `vhigh_bits`.
(rule (lower (vhigh_bits val @ (value_type (multi_lane 8 16))))
(x64_pmovmskb (OperandSize.Size32) val))
(rule (lower (vhigh_bits val @ (value_type (multi_lane 32 4))))
(x64_movmskps (OperandSize.Size32) val))
(rule (lower (vhigh_bits val @ (value_type (multi_lane 64 2))))
(x64_movmskpd (OperandSize.Size32) val))
;; There is no x86 instruction for extracting the high bit of 16-bit lanes so
;; here we:
;; - duplicate the 16-bit lanes of `src` into 8-bit lanes:
;; PACKSSWB([x1, x2, ...], [x1, x2, ...]) = [x1', x2', ..., x1', x2', ...]
;; - use PMOVMSKB to gather the high bits; now we have duplicates, though
;; - shift away the bottom 8 high bits to remove the duplicates.
(rule (lower (vhigh_bits val @ (value_type (multi_lane 16 8))))
(let ((src Xmm val)
(tmp Xmm (x64_packsswb src src))
(tmp Gpr (x64_pmovmskb (OperandSize.Size32) tmp)))
(x64_shr $I64 tmp (Imm8Reg.Imm8 8))))
;; Rules for `iconcat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (iconcat lo @ (value_type $I64) hi))
(value_regs lo hi))
;; Rules for `isplit` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (isplit val @ (value_type $I128)))
(let ((regs ValueRegs val)
(lo Reg (value_regs_get regs 0))
(hi Reg (value_regs_get regs 1)))
(output_pair lo hi)))
;; Rules for `tls_value` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (has_type (tls_model (TlsModel.ElfGd)) (tls_value (symbol_value_data name _ _))))
(elf_tls_get_addr name))
(rule (lower (has_type (tls_model (TlsModel.Macho)) (tls_value (symbol_value_data name _ _))))
(macho_tls_get_addr name))
(rule (lower (has_type (tls_model (TlsModel.Coff)) (tls_value (symbol_value_data name _ _))))
(coff_tls_get_addr name))
;; Rules for `sqmul_round_sat` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule 1 (lower (sqmul_round_sat qx @ (value_type $I16X8) qy))
(if-let $true (use_ssse3))
(let ((src1 Xmm qx)
(src2 Xmm qy)
(mask XmmMem (emit_u128_le_const 0x8000_8000_8000_8000_8000_8000_8000_8000))
(dst Xmm (x64_pmulhrsw src1 src2))
(cmp Xmm (x64_pcmpeqw dst mask)))
(x64_pxor dst cmp)))
;; This operation is defined in wasm as:
;;
;; S.SignedSaturate((x * y + 0x4000) >> 15)
;;
;; so perform all those operations here manually with a lack of the native
;; instruction.
(rule (lower (sqmul_round_sat qx @ (value_type $I16X8) qy))
(let (
(qx Xmm qx)
(qy Xmm qy)
;; Multiply `qx` and `qy` generating 32-bit intermediate results. The
;; 32-bit results have their low-halves stored in `mul_lsb` and the
;; high halves are stored in `mul_msb`. These are then shuffled into
;; `mul_lo` and `mul_hi` which represent the low 4 multiplications
;; and the upper 4 multiplications.
(mul_lsb Xmm (x64_pmullw qx qy))
(mul_msb Xmm (x64_pmulhw qx qy))
(mul_lo Xmm (x64_punpcklwd mul_lsb mul_msb))
(mul_hi Xmm (x64_punpckhwd mul_lsb mul_msb))
;; Add the 0x4000 constant to all multiplications
(val Xmm (x64_movdqu_load (emit_u128_le_const 0x00004000_00004000_00004000_00004000)))
(mul_lo Xmm (x64_paddd mul_lo val))
(mul_hi Xmm (x64_paddd mul_hi val))
;; Perform the right-shift by 15 to all multiplications
(lo Xmm (x64_psrad mul_lo (xmi_imm 15)))
(hi Xmm (x64_psrad mul_hi (xmi_imm 15)))
)
;; And finally perform a saturating 32-to-16-bit conversion.
(x64_packssdw lo hi)))
;; Rules for `x86_pmulhrsw` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (x86_pmulhrsw qx @ (value_type $I16X8) qy))
(if-let $true (use_ssse3))
(x64_pmulhrsw qx qy))
;; Rules for `uunarrow` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; TODO: currently we only lower a special case of `uunarrow` needed to support
;; the translation of wasm's i32x4.trunc_sat_f64x2_u_zero operation.
;; https://github.com/bytecodealliance/wasmtime/issues/4791
;;
;; y = i32x4.trunc_sat_f64x2_u_zero(x) is lowered to:
;; MOVAPD xmm_y, xmm_x
;; XORPD xmm_tmp, xmm_tmp
;; MAXPD xmm_y, xmm_tmp
;; MINPD xmm_y, [wasm_f64x2_splat(4294967295.0)]
;; ROUNDPD xmm_y, xmm_y, 0x0B
;; ADDPD xmm_y, [wasm_f64x2_splat(0x1.0p+52)]
;; SHUFPS xmm_y, xmm_xmp, 0x88
(rule (lower (uunarrow (fcvt_to_uint_sat src @ (value_type $F64X2))
(vconst (u128_from_constant 0))))
(let ((src Xmm src)
;; MOVAPD xmm_y, xmm_x
;; XORPD xmm_tmp, xmm_tmp
(zeros Xmm (xmm_zero $F64X2))
(dst Xmm (x64_maxpd src zeros))
;; 4294967295.0 is equivalent to 0x41EFFFFFFFE00000
(umax_mask XmmMem (emit_u128_le_const 0x41EFFFFFFFE00000_41EFFFFFFFE00000))
;; MINPD xmm_y, [wasm_f64x2_splat(4294967295.0)]
(dst Xmm (x64_minpd dst umax_mask))
;; ROUNDPD xmm_y, xmm_y, 0x0B
(dst Xmm (x64_round $F64X2 dst (RoundImm.RoundZero)))
;; ADDPD xmm_y, [wasm_f64x2_splat(0x1.0p+52)]
(uint_mask XmmMem (emit_u128_le_const 0x4330000000000000_4330000000000000))
(dst Xmm (x64_addpd dst uint_mask)))
;; SHUFPS xmm_y, xmm_xmp, 0x88
(x64_shufps dst zeros 0x88)))
;; Rules for `nop` ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(rule (lower (nop))
(invalid_reg))