| use super::operand::{OperandRef, OperandValue}; |
| use super::place::PlaceRef; |
| use super::{FunctionCx, LocalRef}; |
| |
| use crate::base; |
| use crate::common::{self, IntPredicate}; |
| use crate::traits::*; |
| use crate::MemFlags; |
| |
| use rustc_middle::mir; |
| use rustc_middle::mir::Operand; |
| use rustc_middle::ty::cast::{CastTy, IntTy}; |
| use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout}; |
| use rustc_middle::ty::{self, adjustment::PointerCoercion, Instance, Ty, TyCtxt}; |
| use rustc_session::config::OptLevel; |
| use rustc_span::source_map::{Span, DUMMY_SP}; |
| use rustc_target::abi::{self, FIRST_VARIANT}; |
| |
| impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { |
| #[instrument(level = "trace", skip(self, bx))] |
| pub fn codegen_rvalue( |
| &mut self, |
| bx: &mut Bx, |
| dest: PlaceRef<'tcx, Bx::Value>, |
| rvalue: &mir::Rvalue<'tcx>, |
| ) { |
| match *rvalue { |
| mir::Rvalue::Use(ref operand) => { |
| let cg_operand = self.codegen_operand(bx, operand); |
| // FIXME: consider not copying constants through stack. (Fixable by codegen'ing |
| // constants into `OperandValue::Ref`; why don’t we do that yet if we don’t?) |
| cg_operand.val.store(bx, dest); |
| } |
| |
| mir::Rvalue::Cast( |
| mir::CastKind::PointerCoercion(PointerCoercion::Unsize), |
| ref source, |
| _, |
| ) => { |
| // The destination necessarily contains a fat pointer, so if |
| // it's a scalar pair, it's a fat pointer or newtype thereof. |
| if bx.cx().is_backend_scalar_pair(dest.layout) { |
| // Into-coerce of a thin pointer to a fat pointer -- just |
| // use the operand path. |
| let temp = self.codegen_rvalue_operand(bx, rvalue); |
| temp.val.store(bx, dest); |
| return; |
| } |
| |
| // Unsize of a nontrivial struct. I would prefer for |
| // this to be eliminated by MIR building, but |
| // `CoerceUnsized` can be passed by a where-clause, |
| // so the (generic) MIR may not be able to expand it. |
| let operand = self.codegen_operand(bx, source); |
| match operand.val { |
| OperandValue::Pair(..) | OperandValue::Immediate(_) => { |
| // Unsize from an immediate structure. We don't |
| // really need a temporary alloca here, but |
| // avoiding it would require us to have |
| // `coerce_unsized_into` use `extractvalue` to |
| // index into the struct, and this case isn't |
| // important enough for it. |
| debug!("codegen_rvalue: creating ugly alloca"); |
| let scratch = PlaceRef::alloca(bx, operand.layout); |
| scratch.storage_live(bx); |
| operand.val.store(bx, scratch); |
| base::coerce_unsized_into(bx, scratch, dest); |
| scratch.storage_dead(bx); |
| } |
| OperandValue::Ref(llref, None, align) => { |
| let source = PlaceRef::new_sized_aligned(llref, operand.layout, align); |
| base::coerce_unsized_into(bx, source, dest); |
| } |
| OperandValue::Ref(_, Some(_), _) => { |
| bug!("unsized coercion on an unsized rvalue"); |
| } |
| OperandValue::ZeroSized => { |
| bug!("unsized coercion on a ZST rvalue"); |
| } |
| } |
| } |
| |
| mir::Rvalue::Cast(mir::CastKind::Transmute, ref operand, _ty) => { |
| let src = self.codegen_operand(bx, operand); |
| self.codegen_transmute(bx, src, dest); |
| } |
| |
| mir::Rvalue::Repeat(ref elem, count) => { |
| let cg_elem = self.codegen_operand(bx, elem); |
| |
| // Do not generate the loop for zero-sized elements or empty arrays. |
| if dest.layout.is_zst() { |
| return; |
| } |
| |
| if let OperandValue::Immediate(v) = cg_elem.val { |
| let zero = bx.const_usize(0); |
| let start = dest.project_index(bx, zero).llval; |
| let size = bx.const_usize(dest.layout.size.bytes()); |
| |
| // Use llvm.memset.p0i8.* to initialize all zero arrays |
| if bx.cx().const_to_opt_u128(v, false) == Some(0) { |
| let fill = bx.cx().const_u8(0); |
| bx.memset(start, fill, size, dest.align, MemFlags::empty()); |
| return; |
| } |
| |
| // Use llvm.memset.p0i8.* to initialize byte arrays |
| let v = bx.from_immediate(v); |
| if bx.cx().val_ty(v) == bx.cx().type_i8() { |
| bx.memset(start, v, size, dest.align, MemFlags::empty()); |
| return; |
| } |
| } |
| |
| let count = self |
| .monomorphize(count) |
| .eval_target_usize(bx.cx().tcx(), ty::ParamEnv::reveal_all()); |
| |
| bx.write_operand_repeatedly(cg_elem, count, dest); |
| } |
| |
| mir::Rvalue::Aggregate(ref kind, ref operands) => { |
| let (variant_index, variant_dest, active_field_index) = match **kind { |
| mir::AggregateKind::Adt(_, variant_index, _, _, active_field_index) => { |
| let variant_dest = dest.project_downcast(bx, variant_index); |
| (variant_index, variant_dest, active_field_index) |
| } |
| _ => (FIRST_VARIANT, dest, None), |
| }; |
| if active_field_index.is_some() { |
| assert_eq!(operands.len(), 1); |
| } |
| for (i, operand) in operands.iter_enumerated() { |
| let op = self.codegen_operand(bx, operand); |
| // Do not generate stores and GEPis for zero-sized fields. |
| if !op.layout.is_zst() { |
| let field_index = active_field_index.unwrap_or(i); |
| let field = if let mir::AggregateKind::Array(_) = **kind { |
| let llindex = bx.cx().const_usize(field_index.as_u32().into()); |
| variant_dest.project_index(bx, llindex) |
| } else { |
| variant_dest.project_field(bx, field_index.as_usize()) |
| }; |
| op.val.store(bx, field); |
| } |
| } |
| dest.codegen_set_discr(bx, variant_index); |
| } |
| |
| _ => { |
| assert!(self.rvalue_creates_operand(rvalue, DUMMY_SP)); |
| let temp = self.codegen_rvalue_operand(bx, rvalue); |
| temp.val.store(bx, dest); |
| } |
| } |
| } |
| |
| fn codegen_transmute( |
| &mut self, |
| bx: &mut Bx, |
| src: OperandRef<'tcx, Bx::Value>, |
| dst: PlaceRef<'tcx, Bx::Value>, |
| ) { |
| // The MIR validator enforces no unsized transmutes. |
| debug_assert!(src.layout.is_sized()); |
| debug_assert!(dst.layout.is_sized()); |
| |
| if let Some(val) = self.codegen_transmute_operand(bx, src, dst.layout) { |
| val.store(bx, dst); |
| return; |
| } |
| |
| match src.val { |
| OperandValue::Ref(..) | OperandValue::ZeroSized => { |
| span_bug!( |
| self.mir.span, |
| "Operand path should have handled transmute \ |
| from {src:?} to place {dst:?}" |
| ); |
| } |
| OperandValue::Immediate(..) | OperandValue::Pair(..) => { |
| // When we have immediate(s), the alignment of the source is irrelevant, |
| // so we can store them using the destination's alignment. |
| src.val.store(bx, PlaceRef::new_sized_aligned(dst.llval, src.layout, dst.align)); |
| } |
| } |
| } |
| |
| /// Attempts to transmute an `OperandValue` to another `OperandValue`. |
| /// |
| /// Returns `None` for cases that can't work in that framework, such as for |
| /// `Immediate`->`Ref` that needs an `alloc` to get the location. |
| fn codegen_transmute_operand( |
| &mut self, |
| bx: &mut Bx, |
| operand: OperandRef<'tcx, Bx::Value>, |
| cast: TyAndLayout<'tcx>, |
| ) -> Option<OperandValue<Bx::Value>> { |
| // Check for transmutes that are always UB. |
| if operand.layout.size != cast.size |
| || operand.layout.abi.is_uninhabited() |
| || cast.abi.is_uninhabited() |
| { |
| if !operand.layout.abi.is_uninhabited() { |
| // Since this is known statically and the input could have existed |
| // without already having hit UB, might as well trap for it. |
| bx.abort(); |
| } |
| |
| // Because this transmute is UB, return something easy to generate, |
| // since it's fine that later uses of the value are probably UB. |
| return Some(OperandValue::poison(bx, cast)); |
| } |
| |
| let operand_kind = self.value_kind(operand.layout); |
| let cast_kind = self.value_kind(cast); |
| |
| match operand.val { |
| OperandValue::Ref(ptr, meta, align) => { |
| debug_assert_eq!(meta, None); |
| debug_assert!(matches!(operand_kind, OperandValueKind::Ref)); |
| let fake_place = PlaceRef::new_sized_aligned(ptr, cast, align); |
| Some(bx.load_operand(fake_place).val) |
| } |
| OperandValue::ZeroSized => { |
| let OperandValueKind::ZeroSized = operand_kind else { |
| bug!("Found {operand_kind:?} for operand {operand:?}"); |
| }; |
| if let OperandValueKind::ZeroSized = cast_kind { |
| Some(OperandValue::ZeroSized) |
| } else { |
| None |
| } |
| } |
| OperandValue::Immediate(imm) => { |
| let OperandValueKind::Immediate(in_scalar) = operand_kind else { |
| bug!("Found {operand_kind:?} for operand {operand:?}"); |
| }; |
| if let OperandValueKind::Immediate(out_scalar) = cast_kind |
| && in_scalar.size(self.cx) == out_scalar.size(self.cx) |
| { |
| let operand_bty = bx.backend_type(operand.layout); |
| let cast_bty = bx.backend_type(cast); |
| Some(OperandValue::Immediate(self.transmute_immediate( |
| bx, |
| imm, |
| in_scalar, |
| operand_bty, |
| out_scalar, |
| cast_bty, |
| ))) |
| } else { |
| None |
| } |
| } |
| OperandValue::Pair(imm_a, imm_b) => { |
| let OperandValueKind::Pair(in_a, in_b) = operand_kind else { |
| bug!("Found {operand_kind:?} for operand {operand:?}"); |
| }; |
| if let OperandValueKind::Pair(out_a, out_b) = cast_kind |
| && in_a.size(self.cx) == out_a.size(self.cx) |
| && in_b.size(self.cx) == out_b.size(self.cx) |
| { |
| let in_a_ibty = bx.scalar_pair_element_backend_type(operand.layout, 0, false); |
| let in_b_ibty = bx.scalar_pair_element_backend_type(operand.layout, 1, false); |
| let out_a_ibty = bx.scalar_pair_element_backend_type(cast, 0, false); |
| let out_b_ibty = bx.scalar_pair_element_backend_type(cast, 1, false); |
| Some(OperandValue::Pair( |
| self.transmute_immediate(bx, imm_a, in_a, in_a_ibty, out_a, out_a_ibty), |
| self.transmute_immediate(bx, imm_b, in_b, in_b_ibty, out_b, out_b_ibty), |
| )) |
| } else { |
| None |
| } |
| } |
| } |
| } |
| |
| /// Transmutes one of the immediates from an [`OperandValue::Immediate`] |
| /// or an [`OperandValue::Pair`] to an immediate of the target type. |
| /// |
| /// `to_backend_ty` must be the *non*-immediate backend type (so it will be |
| /// `i8`, not `i1`, for `bool`-like types.) |
| fn transmute_immediate( |
| &self, |
| bx: &mut Bx, |
| mut imm: Bx::Value, |
| from_scalar: abi::Scalar, |
| from_backend_ty: Bx::Type, |
| to_scalar: abi::Scalar, |
| to_backend_ty: Bx::Type, |
| ) -> Bx::Value { |
| debug_assert_eq!(from_scalar.size(self.cx), to_scalar.size(self.cx)); |
| |
| use abi::Primitive::*; |
| imm = bx.from_immediate(imm); |
| |
| // When scalars are passed by value, there's no metadata recording their |
| // valid ranges. For example, `char`s are passed as just `i32`, with no |
| // way for LLVM to know that they're 0x10FFFF at most. Thus we assume |
| // the range of the input value too, not just the output range. |
| self.assume_scalar_range(bx, imm, from_scalar, from_backend_ty); |
| |
| imm = match (from_scalar.primitive(), to_scalar.primitive()) { |
| (Int(..) | F32 | F64, Int(..) | F32 | F64) => bx.bitcast(imm, to_backend_ty), |
| (Pointer(..), Pointer(..)) => bx.pointercast(imm, to_backend_ty), |
| (Int(..), Pointer(..)) => bx.inttoptr(imm, to_backend_ty), |
| (Pointer(..), Int(..)) => bx.ptrtoint(imm, to_backend_ty), |
| (F32 | F64, Pointer(..)) => { |
| let int_imm = bx.bitcast(imm, bx.cx().type_isize()); |
| bx.inttoptr(int_imm, to_backend_ty) |
| } |
| (Pointer(..), F32 | F64) => { |
| let int_imm = bx.ptrtoint(imm, bx.cx().type_isize()); |
| bx.bitcast(int_imm, to_backend_ty) |
| } |
| }; |
| self.assume_scalar_range(bx, imm, to_scalar, to_backend_ty); |
| imm = bx.to_immediate_scalar(imm, to_scalar); |
| imm |
| } |
| |
| fn assume_scalar_range( |
| &self, |
| bx: &mut Bx, |
| imm: Bx::Value, |
| scalar: abi::Scalar, |
| backend_ty: Bx::Type, |
| ) { |
| if matches!(self.cx.sess().opts.optimize, OptLevel::No | OptLevel::Less) |
| // For now, the critical niches are all over `Int`eger values. |
| // Should floating-point values or pointers ever get more complex |
| // niches, then this code will probably want to handle them too. |
| || !matches!(scalar.primitive(), abi::Primitive::Int(..)) |
| || scalar.is_always_valid(self.cx) |
| { |
| return; |
| } |
| |
| let abi::WrappingRange { start, end } = scalar.valid_range(self.cx); |
| |
| if start <= end { |
| if start > 0 { |
| let low = bx.const_uint_big(backend_ty, start); |
| let cmp = bx.icmp(IntPredicate::IntUGE, imm, low); |
| bx.assume(cmp); |
| } |
| |
| let type_max = scalar.size(self.cx).unsigned_int_max(); |
| if end < type_max { |
| let high = bx.const_uint_big(backend_ty, end); |
| let cmp = bx.icmp(IntPredicate::IntULE, imm, high); |
| bx.assume(cmp); |
| } |
| } else { |
| let low = bx.const_uint_big(backend_ty, start); |
| let cmp_low = bx.icmp(IntPredicate::IntUGE, imm, low); |
| |
| let high = bx.const_uint_big(backend_ty, end); |
| let cmp_high = bx.icmp(IntPredicate::IntULE, imm, high); |
| |
| let or = bx.or(cmp_low, cmp_high); |
| bx.assume(or); |
| } |
| } |
| |
| pub fn codegen_rvalue_unsized( |
| &mut self, |
| bx: &mut Bx, |
| indirect_dest: PlaceRef<'tcx, Bx::Value>, |
| rvalue: &mir::Rvalue<'tcx>, |
| ) { |
| debug!( |
| "codegen_rvalue_unsized(indirect_dest.llval={:?}, rvalue={:?})", |
| indirect_dest.llval, rvalue |
| ); |
| |
| match *rvalue { |
| mir::Rvalue::Use(ref operand) => { |
| let cg_operand = self.codegen_operand(bx, operand); |
| cg_operand.val.store_unsized(bx, indirect_dest); |
| } |
| |
| _ => bug!("unsized assignment other than `Rvalue::Use`"), |
| } |
| } |
| |
| pub fn codegen_rvalue_operand( |
| &mut self, |
| bx: &mut Bx, |
| rvalue: &mir::Rvalue<'tcx>, |
| ) -> OperandRef<'tcx, Bx::Value> { |
| assert!( |
| self.rvalue_creates_operand(rvalue, DUMMY_SP), |
| "cannot codegen {rvalue:?} to operand", |
| ); |
| |
| match *rvalue { |
| mir::Rvalue::Cast(ref kind, ref source, mir_cast_ty) => { |
| let operand = self.codegen_operand(bx, source); |
| debug!("cast operand is {:?}", operand); |
| let cast = bx.cx().layout_of(self.monomorphize(mir_cast_ty)); |
| |
| let val = match *kind { |
| mir::CastKind::PointerExposeAddress => { |
| assert!(bx.cx().is_backend_immediate(cast)); |
| let llptr = operand.immediate(); |
| let llcast_ty = bx.cx().immediate_backend_type(cast); |
| let lladdr = bx.ptrtoint(llptr, llcast_ty); |
| OperandValue::Immediate(lladdr) |
| } |
| mir::CastKind::PointerCoercion(PointerCoercion::ReifyFnPointer) => { |
| match *operand.layout.ty.kind() { |
| ty::FnDef(def_id, args) => { |
| let instance = ty::Instance::resolve_for_fn_ptr( |
| bx.tcx(), |
| ty::ParamEnv::reveal_all(), |
| def_id, |
| args, |
| ) |
| .unwrap() |
| .polymorphize(bx.cx().tcx()); |
| OperandValue::Immediate(bx.get_fn_addr(instance)) |
| } |
| _ => bug!("{} cannot be reified to a fn ptr", operand.layout.ty), |
| } |
| } |
| mir::CastKind::PointerCoercion(PointerCoercion::ClosureFnPointer(_)) => { |
| match *operand.layout.ty.kind() { |
| ty::Closure(def_id, args) => { |
| let instance = Instance::resolve_closure( |
| bx.cx().tcx(), |
| def_id, |
| args, |
| ty::ClosureKind::FnOnce, |
| ) |
| .expect("failed to normalize and resolve closure during codegen") |
| .polymorphize(bx.cx().tcx()); |
| OperandValue::Immediate(bx.cx().get_fn_addr(instance)) |
| } |
| _ => bug!("{} cannot be cast to a fn ptr", operand.layout.ty), |
| } |
| } |
| mir::CastKind::PointerCoercion(PointerCoercion::UnsafeFnPointer) => { |
| // This is a no-op at the LLVM level. |
| operand.val |
| } |
| mir::CastKind::PointerCoercion(PointerCoercion::Unsize) => { |
| assert!(bx.cx().is_backend_scalar_pair(cast)); |
| let (lldata, llextra) = match operand.val { |
| OperandValue::Pair(lldata, llextra) => { |
| // unsize from a fat pointer -- this is a |
| // "trait-object-to-supertrait" coercion. |
| (lldata, Some(llextra)) |
| } |
| OperandValue::Immediate(lldata) => { |
| // "standard" unsize |
| (lldata, None) |
| } |
| OperandValue::Ref(..) => { |
| bug!("by-ref operand {:?} in `codegen_rvalue_operand`", operand); |
| } |
| OperandValue::ZeroSized => { |
| bug!("zero-sized operand {:?} in `codegen_rvalue_operand`", operand); |
| } |
| }; |
| let (lldata, llextra) = |
| base::unsize_ptr(bx, lldata, operand.layout.ty, cast.ty, llextra); |
| OperandValue::Pair(lldata, llextra) |
| } |
| mir::CastKind::PointerCoercion(PointerCoercion::MutToConstPointer) |
| | mir::CastKind::PtrToPtr |
| if bx.cx().is_backend_scalar_pair(operand.layout) => |
| { |
| if let OperandValue::Pair(data_ptr, meta) = operand.val { |
| if bx.cx().is_backend_scalar_pair(cast) { |
| OperandValue::Pair(data_ptr, meta) |
| } else { |
| // Cast of fat-ptr to thin-ptr is an extraction of data-ptr. |
| OperandValue::Immediate(data_ptr) |
| } |
| } else { |
| bug!("unexpected non-pair operand"); |
| } |
| } |
| mir::CastKind::DynStar => { |
| let (lldata, llextra) = match operand.val { |
| OperandValue::Ref(_, _, _) => todo!(), |
| OperandValue::Immediate(v) => (v, None), |
| OperandValue::Pair(v, l) => (v, Some(l)), |
| OperandValue::ZeroSized => bug!("ZST -- which is not PointerLike -- in DynStar"), |
| }; |
| let (lldata, llextra) = |
| base::cast_to_dyn_star(bx, lldata, operand.layout, cast.ty, llextra); |
| OperandValue::Pair(lldata, llextra) |
| } |
| mir::CastKind::PointerCoercion( |
| PointerCoercion::MutToConstPointer | PointerCoercion::ArrayToPointer, |
| ) |
| | mir::CastKind::IntToInt |
| | mir::CastKind::FloatToInt |
| | mir::CastKind::FloatToFloat |
| | mir::CastKind::IntToFloat |
| | mir::CastKind::PtrToPtr |
| | mir::CastKind::FnPtrToPtr |
| |
| // Since int2ptr can have arbitrary integer types as input (so we have to do |
| // sign extension and all that), it is currently best handled in the same code |
| // path as the other integer-to-X casts. |
| | mir::CastKind::PointerFromExposedAddress => { |
| assert!(bx.cx().is_backend_immediate(cast)); |
| let ll_t_out = bx.cx().immediate_backend_type(cast); |
| if operand.layout.abi.is_uninhabited() { |
| let val = OperandValue::Immediate(bx.cx().const_poison(ll_t_out)); |
| return OperandRef { val, layout: cast }; |
| } |
| let r_t_in = |
| CastTy::from_ty(operand.layout.ty).expect("bad input type for cast"); |
| let r_t_out = CastTy::from_ty(cast.ty).expect("bad output type for cast"); |
| let ll_t_in = bx.cx().immediate_backend_type(operand.layout); |
| let llval = operand.immediate(); |
| |
| let newval = match (r_t_in, r_t_out) { |
| (CastTy::Int(i), CastTy::Int(_)) => { |
| bx.intcast(llval, ll_t_out, i.is_signed()) |
| } |
| (CastTy::Float, CastTy::Float) => { |
| let srcsz = bx.cx().float_width(ll_t_in); |
| let dstsz = bx.cx().float_width(ll_t_out); |
| if dstsz > srcsz { |
| bx.fpext(llval, ll_t_out) |
| } else if srcsz > dstsz { |
| bx.fptrunc(llval, ll_t_out) |
| } else { |
| llval |
| } |
| } |
| (CastTy::Int(i), CastTy::Float) => { |
| if i.is_signed() { |
| bx.sitofp(llval, ll_t_out) |
| } else { |
| bx.uitofp(llval, ll_t_out) |
| } |
| } |
| (CastTy::Ptr(_) | CastTy::FnPtr, CastTy::Ptr(_)) => { |
| bx.pointercast(llval, ll_t_out) |
| } |
| (CastTy::Int(i), CastTy::Ptr(_)) => { |
| let usize_llval = |
| bx.intcast(llval, bx.cx().type_isize(), i.is_signed()); |
| bx.inttoptr(usize_llval, ll_t_out) |
| } |
| (CastTy::Float, CastTy::Int(IntTy::I)) => { |
| bx.cast_float_to_int(true, llval, ll_t_out) |
| } |
| (CastTy::Float, CastTy::Int(_)) => { |
| bx.cast_float_to_int(false, llval, ll_t_out) |
| } |
| _ => bug!("unsupported cast: {:?} to {:?}", operand.layout.ty, cast.ty), |
| }; |
| OperandValue::Immediate(newval) |
| } |
| mir::CastKind::Transmute => { |
| self.codegen_transmute_operand(bx, operand, cast).unwrap_or_else(|| { |
| bug!("Unsupported transmute-as-operand of {operand:?} to {cast:?}"); |
| }) |
| } |
| }; |
| OperandRef { val, layout: cast } |
| } |
| |
| mir::Rvalue::Ref(_, bk, place) => { |
| let mk_ref = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| { |
| Ty::new_ref( |
| tcx, |
| tcx.lifetimes.re_erased, |
| ty::TypeAndMut { ty, mutbl: bk.to_mutbl_lossy() }, |
| ) |
| }; |
| self.codegen_place_to_pointer(bx, place, mk_ref) |
| } |
| |
| mir::Rvalue::CopyForDeref(place) => self.codegen_operand(bx, &Operand::Copy(place)), |
| mir::Rvalue::AddressOf(mutability, place) => { |
| let mk_ptr = move |tcx: TyCtxt<'tcx>, ty: Ty<'tcx>| { |
| Ty::new_ptr(tcx, ty::TypeAndMut { ty, mutbl: mutability }) |
| }; |
| self.codegen_place_to_pointer(bx, place, mk_ptr) |
| } |
| |
| mir::Rvalue::Len(place) => { |
| let size = self.evaluate_array_len(bx, place); |
| OperandRef { |
| val: OperandValue::Immediate(size), |
| layout: bx.cx().layout_of(bx.tcx().types.usize), |
| } |
| } |
| |
| mir::Rvalue::BinaryOp(op, box (ref lhs, ref rhs)) => { |
| let lhs = self.codegen_operand(bx, lhs); |
| let rhs = self.codegen_operand(bx, rhs); |
| let llresult = match (lhs.val, rhs.val) { |
| ( |
| OperandValue::Pair(lhs_addr, lhs_extra), |
| OperandValue::Pair(rhs_addr, rhs_extra), |
| ) => self.codegen_fat_ptr_binop( |
| bx, |
| op, |
| lhs_addr, |
| lhs_extra, |
| rhs_addr, |
| rhs_extra, |
| lhs.layout.ty, |
| ), |
| |
| (OperandValue::Immediate(lhs_val), OperandValue::Immediate(rhs_val)) => { |
| self.codegen_scalar_binop(bx, op, lhs_val, rhs_val, lhs.layout.ty) |
| } |
| |
| _ => bug!(), |
| }; |
| OperandRef { |
| val: OperandValue::Immediate(llresult), |
| layout: bx.cx().layout_of(op.ty(bx.tcx(), lhs.layout.ty, rhs.layout.ty)), |
| } |
| } |
| mir::Rvalue::CheckedBinaryOp(op, box (ref lhs, ref rhs)) => { |
| let lhs = self.codegen_operand(bx, lhs); |
| let rhs = self.codegen_operand(bx, rhs); |
| let result = self.codegen_scalar_checked_binop( |
| bx, |
| op, |
| lhs.immediate(), |
| rhs.immediate(), |
| lhs.layout.ty, |
| ); |
| let val_ty = op.ty(bx.tcx(), lhs.layout.ty, rhs.layout.ty); |
| let operand_ty = Ty::new_tup(bx.tcx(), &[val_ty, bx.tcx().types.bool]); |
| OperandRef { val: result, layout: bx.cx().layout_of(operand_ty) } |
| } |
| |
| mir::Rvalue::UnaryOp(op, ref operand) => { |
| let operand = self.codegen_operand(bx, operand); |
| let lloperand = operand.immediate(); |
| let is_float = operand.layout.ty.is_floating_point(); |
| let llval = match op { |
| mir::UnOp::Not => bx.not(lloperand), |
| mir::UnOp::Neg => { |
| if is_float { |
| bx.fneg(lloperand) |
| } else { |
| bx.neg(lloperand) |
| } |
| } |
| }; |
| OperandRef { val: OperandValue::Immediate(llval), layout: operand.layout } |
| } |
| |
| mir::Rvalue::Discriminant(ref place) => { |
| let discr_ty = rvalue.ty(self.mir, bx.tcx()); |
| let discr_ty = self.monomorphize(discr_ty); |
| let discr = self.codegen_place(bx, place.as_ref()).codegen_get_discr(bx, discr_ty); |
| OperandRef { |
| val: OperandValue::Immediate(discr), |
| layout: self.cx.layout_of(discr_ty), |
| } |
| } |
| |
| mir::Rvalue::NullaryOp(ref null_op, ty) => { |
| let ty = self.monomorphize(ty); |
| let layout = bx.cx().layout_of(ty); |
| let val = match null_op { |
| mir::NullOp::SizeOf => { |
| assert!(bx.cx().type_is_sized(ty)); |
| layout.size.bytes() |
| } |
| mir::NullOp::AlignOf => { |
| assert!(bx.cx().type_is_sized(ty)); |
| layout.align.abi.bytes() |
| } |
| mir::NullOp::OffsetOf(fields) => { |
| layout.offset_of_subfield(bx.cx(), fields.iter().map(|f| f.index())).bytes() |
| } |
| }; |
| let val = bx.cx().const_usize(val); |
| let tcx = self.cx.tcx(); |
| OperandRef { |
| val: OperandValue::Immediate(val), |
| layout: self.cx.layout_of(tcx.types.usize), |
| } |
| } |
| |
| mir::Rvalue::ThreadLocalRef(def_id) => { |
| assert!(bx.cx().tcx().is_static(def_id)); |
| let layout = bx.layout_of(bx.cx().tcx().static_ptr_ty(def_id)); |
| let static_ = if !def_id.is_local() && bx.cx().tcx().needs_thread_local_shim(def_id) |
| { |
| let instance = ty::Instance { |
| def: ty::InstanceDef::ThreadLocalShim(def_id), |
| args: ty::GenericArgs::empty(), |
| }; |
| let fn_ptr = bx.get_fn_addr(instance); |
| let fn_abi = bx.fn_abi_of_instance(instance, ty::List::empty()); |
| let fn_ty = bx.fn_decl_backend_type(&fn_abi); |
| let fn_attrs = if bx.tcx().def_kind(instance.def_id()).has_codegen_attrs() { |
| Some(bx.tcx().codegen_fn_attrs(instance.def_id())) |
| } else { |
| None |
| }; |
| bx.call(fn_ty, fn_attrs, Some(fn_abi), fn_ptr, &[], None) |
| } else { |
| bx.get_static(def_id) |
| }; |
| OperandRef { val: OperandValue::Immediate(static_), layout } |
| } |
| mir::Rvalue::Use(ref operand) => self.codegen_operand(bx, operand), |
| mir::Rvalue::Repeat(..) | mir::Rvalue::Aggregate(..) => { |
| // According to `rvalue_creates_operand`, only ZST |
| // aggregate rvalues are allowed to be operands. |
| let ty = rvalue.ty(self.mir, self.cx.tcx()); |
| OperandRef::zero_sized(self.cx.layout_of(self.monomorphize(ty))) |
| } |
| mir::Rvalue::ShallowInitBox(ref operand, content_ty) => { |
| let operand = self.codegen_operand(bx, operand); |
| let val = operand.immediate(); |
| |
| let content_ty = self.monomorphize(content_ty); |
| let box_layout = bx.cx().layout_of(Ty::new_box(bx.tcx(), content_ty)); |
| |
| OperandRef { val: OperandValue::Immediate(val), layout: box_layout } |
| } |
| } |
| } |
| |
| fn evaluate_array_len(&mut self, bx: &mut Bx, place: mir::Place<'tcx>) -> Bx::Value { |
| // ZST are passed as operands and require special handling |
| // because codegen_place() panics if Local is operand. |
| if let Some(index) = place.as_local() { |
| if let LocalRef::Operand(op) = self.locals[index] { |
| if let ty::Array(_, n) = op.layout.ty.kind() { |
| let n = n.eval_target_usize(bx.cx().tcx(), ty::ParamEnv::reveal_all()); |
| return bx.cx().const_usize(n); |
| } |
| } |
| } |
| // use common size calculation for non zero-sized types |
| let cg_value = self.codegen_place(bx, place.as_ref()); |
| cg_value.len(bx.cx()) |
| } |
| |
| /// Codegen an `Rvalue::AddressOf` or `Rvalue::Ref` |
| fn codegen_place_to_pointer( |
| &mut self, |
| bx: &mut Bx, |
| place: mir::Place<'tcx>, |
| mk_ptr_ty: impl FnOnce(TyCtxt<'tcx>, Ty<'tcx>) -> Ty<'tcx>, |
| ) -> OperandRef<'tcx, Bx::Value> { |
| let cg_place = self.codegen_place(bx, place.as_ref()); |
| |
| let ty = cg_place.layout.ty; |
| |
| // Note: places are indirect, so storing the `llval` into the |
| // destination effectively creates a reference. |
| let val = if !bx.cx().type_has_metadata(ty) { |
| OperandValue::Immediate(cg_place.llval) |
| } else { |
| OperandValue::Pair(cg_place.llval, cg_place.llextra.unwrap()) |
| }; |
| OperandRef { val, layout: self.cx.layout_of(mk_ptr_ty(self.cx.tcx(), ty)) } |
| } |
| |
| pub fn codegen_scalar_binop( |
| &mut self, |
| bx: &mut Bx, |
| op: mir::BinOp, |
| lhs: Bx::Value, |
| rhs: Bx::Value, |
| input_ty: Ty<'tcx>, |
| ) -> Bx::Value { |
| let is_float = input_ty.is_floating_point(); |
| let is_signed = input_ty.is_signed(); |
| match op { |
| mir::BinOp::Add => { |
| if is_float { |
| bx.fadd(lhs, rhs) |
| } else { |
| bx.add(lhs, rhs) |
| } |
| } |
| mir::BinOp::AddUnchecked => { |
| if is_signed { |
| bx.unchecked_sadd(lhs, rhs) |
| } else { |
| bx.unchecked_uadd(lhs, rhs) |
| } |
| } |
| mir::BinOp::Sub => { |
| if is_float { |
| bx.fsub(lhs, rhs) |
| } else { |
| bx.sub(lhs, rhs) |
| } |
| } |
| mir::BinOp::SubUnchecked => { |
| if is_signed { |
| bx.unchecked_ssub(lhs, rhs) |
| } else { |
| bx.unchecked_usub(lhs, rhs) |
| } |
| } |
| mir::BinOp::Mul => { |
| if is_float { |
| bx.fmul(lhs, rhs) |
| } else { |
| bx.mul(lhs, rhs) |
| } |
| } |
| mir::BinOp::MulUnchecked => { |
| if is_signed { |
| bx.unchecked_smul(lhs, rhs) |
| } else { |
| bx.unchecked_umul(lhs, rhs) |
| } |
| } |
| mir::BinOp::Div => { |
| if is_float { |
| bx.fdiv(lhs, rhs) |
| } else if is_signed { |
| bx.sdiv(lhs, rhs) |
| } else { |
| bx.udiv(lhs, rhs) |
| } |
| } |
| mir::BinOp::Rem => { |
| if is_float { |
| bx.frem(lhs, rhs) |
| } else if is_signed { |
| bx.srem(lhs, rhs) |
| } else { |
| bx.urem(lhs, rhs) |
| } |
| } |
| mir::BinOp::BitOr => bx.or(lhs, rhs), |
| mir::BinOp::BitAnd => bx.and(lhs, rhs), |
| mir::BinOp::BitXor => bx.xor(lhs, rhs), |
| mir::BinOp::Offset => { |
| let pointee_type = input_ty |
| .builtin_deref(true) |
| .unwrap_or_else(|| bug!("deref of non-pointer {:?}", input_ty)) |
| .ty; |
| let pointee_layout = bx.cx().layout_of(pointee_type); |
| if pointee_layout.is_zst() { |
| // `Offset` works in terms of the size of pointee, |
| // so offsetting a pointer to ZST is a noop. |
| lhs |
| } else { |
| let llty = bx.cx().backend_type(pointee_layout); |
| bx.inbounds_gep(llty, lhs, &[rhs]) |
| } |
| } |
| mir::BinOp::Shl => common::build_masked_lshift(bx, lhs, rhs), |
| mir::BinOp::ShlUnchecked => { |
| let rhs = base::cast_shift_expr_rhs(bx, lhs, rhs); |
| bx.shl(lhs, rhs) |
| } |
| mir::BinOp::Shr => common::build_masked_rshift(bx, input_ty, lhs, rhs), |
| mir::BinOp::ShrUnchecked => { |
| let rhs = base::cast_shift_expr_rhs(bx, lhs, rhs); |
| if is_signed { bx.ashr(lhs, rhs) } else { bx.lshr(lhs, rhs) } |
| } |
| mir::BinOp::Ne |
| | mir::BinOp::Lt |
| | mir::BinOp::Gt |
| | mir::BinOp::Eq |
| | mir::BinOp::Le |
| | mir::BinOp::Ge => { |
| if is_float { |
| bx.fcmp(base::bin_op_to_fcmp_predicate(op.to_hir_binop()), lhs, rhs) |
| } else { |
| bx.icmp(base::bin_op_to_icmp_predicate(op.to_hir_binop(), is_signed), lhs, rhs) |
| } |
| } |
| } |
| } |
| |
| pub fn codegen_fat_ptr_binop( |
| &mut self, |
| bx: &mut Bx, |
| op: mir::BinOp, |
| lhs_addr: Bx::Value, |
| lhs_extra: Bx::Value, |
| rhs_addr: Bx::Value, |
| rhs_extra: Bx::Value, |
| _input_ty: Ty<'tcx>, |
| ) -> Bx::Value { |
| match op { |
| mir::BinOp::Eq => { |
| let lhs = bx.icmp(IntPredicate::IntEQ, lhs_addr, rhs_addr); |
| let rhs = bx.icmp(IntPredicate::IntEQ, lhs_extra, rhs_extra); |
| bx.and(lhs, rhs) |
| } |
| mir::BinOp::Ne => { |
| let lhs = bx.icmp(IntPredicate::IntNE, lhs_addr, rhs_addr); |
| let rhs = bx.icmp(IntPredicate::IntNE, lhs_extra, rhs_extra); |
| bx.or(lhs, rhs) |
| } |
| mir::BinOp::Le | mir::BinOp::Lt | mir::BinOp::Ge | mir::BinOp::Gt => { |
| // a OP b ~ a.0 STRICT(OP) b.0 | (a.0 == b.0 && a.1 OP a.1) |
| let (op, strict_op) = match op { |
| mir::BinOp::Lt => (IntPredicate::IntULT, IntPredicate::IntULT), |
| mir::BinOp::Le => (IntPredicate::IntULE, IntPredicate::IntULT), |
| mir::BinOp::Gt => (IntPredicate::IntUGT, IntPredicate::IntUGT), |
| mir::BinOp::Ge => (IntPredicate::IntUGE, IntPredicate::IntUGT), |
| _ => bug!(), |
| }; |
| let lhs = bx.icmp(strict_op, lhs_addr, rhs_addr); |
| let and_lhs = bx.icmp(IntPredicate::IntEQ, lhs_addr, rhs_addr); |
| let and_rhs = bx.icmp(op, lhs_extra, rhs_extra); |
| let rhs = bx.and(and_lhs, and_rhs); |
| bx.or(lhs, rhs) |
| } |
| _ => { |
| bug!("unexpected fat ptr binop"); |
| } |
| } |
| } |
| |
| pub fn codegen_scalar_checked_binop( |
| &mut self, |
| bx: &mut Bx, |
| op: mir::BinOp, |
| lhs: Bx::Value, |
| rhs: Bx::Value, |
| input_ty: Ty<'tcx>, |
| ) -> OperandValue<Bx::Value> { |
| let (val, of) = match op { |
| // These are checked using intrinsics |
| mir::BinOp::Add | mir::BinOp::Sub | mir::BinOp::Mul => { |
| let oop = match op { |
| mir::BinOp::Add => OverflowOp::Add, |
| mir::BinOp::Sub => OverflowOp::Sub, |
| mir::BinOp::Mul => OverflowOp::Mul, |
| _ => unreachable!(), |
| }; |
| bx.checked_binop(oop, input_ty, lhs, rhs) |
| } |
| _ => bug!("Operator `{:?}` is not a checkable operator", op), |
| }; |
| |
| OperandValue::Pair(val, of) |
| } |
| } |
| |
| impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { |
| pub fn rvalue_creates_operand(&self, rvalue: &mir::Rvalue<'tcx>, span: Span) -> bool { |
| match *rvalue { |
| mir::Rvalue::Cast(mir::CastKind::Transmute, ref operand, cast_ty) => { |
| let operand_ty = operand.ty(self.mir, self.cx.tcx()); |
| let cast_layout = self.cx.layout_of(self.monomorphize(cast_ty)); |
| let operand_layout = self.cx.layout_of(self.monomorphize(operand_ty)); |
| |
| match (self.value_kind(operand_layout), self.value_kind(cast_layout)) { |
| // Can always load from a pointer as needed |
| (OperandValueKind::Ref, _) => true, |
| |
| // ZST-to-ZST is the easiest thing ever |
| (OperandValueKind::ZeroSized, OperandValueKind::ZeroSized) => true, |
| |
| // But if only one of them is a ZST the sizes can't match |
| (OperandValueKind::ZeroSized, _) | (_, OperandValueKind::ZeroSized) => false, |
| |
| // Need to generate an `alloc` to get a pointer from an immediate |
| (OperandValueKind::Immediate(..) | OperandValueKind::Pair(..), OperandValueKind::Ref) => false, |
| |
| // When we have scalar immediates, we can only convert things |
| // where the sizes match, to avoid endianness questions. |
| (OperandValueKind::Immediate(a), OperandValueKind::Immediate(b)) => |
| a.size(self.cx) == b.size(self.cx), |
| (OperandValueKind::Pair(a0, a1), OperandValueKind::Pair(b0, b1)) => |
| a0.size(self.cx) == b0.size(self.cx) && a1.size(self.cx) == b1.size(self.cx), |
| |
| // Send mixings between scalars and pairs through the memory route |
| // FIXME: Maybe this could use insertvalue/extractvalue instead? |
| (OperandValueKind::Immediate(..), OperandValueKind::Pair(..)) | |
| (OperandValueKind::Pair(..), OperandValueKind::Immediate(..)) => false, |
| } |
| } |
| mir::Rvalue::Ref(..) | |
| mir::Rvalue::CopyForDeref(..) | |
| mir::Rvalue::AddressOf(..) | |
| mir::Rvalue::Len(..) | |
| mir::Rvalue::Cast(..) | // (*) |
| mir::Rvalue::ShallowInitBox(..) | // (*) |
| mir::Rvalue::BinaryOp(..) | |
| mir::Rvalue::CheckedBinaryOp(..) | |
| mir::Rvalue::UnaryOp(..) | |
| mir::Rvalue::Discriminant(..) | |
| mir::Rvalue::NullaryOp(..) | |
| mir::Rvalue::ThreadLocalRef(_) | |
| mir::Rvalue::Use(..) => // (*) |
| true, |
| mir::Rvalue::Repeat(..) | |
| mir::Rvalue::Aggregate(..) => { |
| let ty = rvalue.ty(self.mir, self.cx.tcx()); |
| let ty = self.monomorphize(ty); |
| self.cx.spanned_layout_of(ty, span).is_zst() |
| } |
| } |
| |
| // (*) this is only true if the type is suitable |
| } |
| |
| /// Gets which variant of [`OperandValue`] is expected for a particular type. |
| fn value_kind(&self, layout: TyAndLayout<'tcx>) -> OperandValueKind { |
| if layout.is_zst() { |
| OperandValueKind::ZeroSized |
| } else if self.cx.is_backend_immediate(layout) { |
| debug_assert!(!self.cx.is_backend_scalar_pair(layout)); |
| OperandValueKind::Immediate(match layout.abi { |
| abi::Abi::Scalar(s) => s, |
| abi::Abi::Vector { element, .. } => element, |
| x => span_bug!(self.mir.span, "Couldn't translate {x:?} as backend immediate"), |
| }) |
| } else if self.cx.is_backend_scalar_pair(layout) { |
| let abi::Abi::ScalarPair(s1, s2) = layout.abi else { |
| span_bug!( |
| self.mir.span, |
| "Couldn't translate {:?} as backend scalar pair", |
| layout.abi, |
| ); |
| }; |
| OperandValueKind::Pair(s1, s2) |
| } else { |
| OperandValueKind::Ref |
| } |
| } |
| } |
| |
| /// The variants of this match [`OperandValue`], giving details about the |
| /// backend values that will be held in that other type. |
| #[derive(Debug, Copy, Clone)] |
| enum OperandValueKind { |
| Ref, |
| Immediate(abi::Scalar), |
| Pair(abi::Scalar, abi::Scalar), |
| ZeroSized, |
| } |
