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android / toolchain / jdk / jdk11 / refs/heads/main / . / src / hotspot / cpu / aarch64 / gc / shenandoah / shenandoahBarrierSetAssembler_aarch64.cpp
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/*
* Copyright (c) 2018, 2020, Red Hat, Inc. All rights reserved.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "gc/shenandoah/shenandoahBarrierSet.hpp"
#include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
#include "gc/shenandoah/shenandoahForwarding.hpp"
#include "gc/shenandoah/shenandoahHeap.hpp"
#include "gc/shenandoah/shenandoahHeapRegion.hpp"
#include "gc/shenandoah/shenandoahRuntime.hpp"
#include "gc/shenandoah/shenandoahThreadLocalData.hpp"
#include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp"
#include "interpreter/interpreter.hpp"
#include "interpreter/interp_masm.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/thread.hpp"
#ifdef COMPILER1
#include "c1/c1_LIRAssembler.hpp"
#include "c1/c1_MacroAssembler.hpp"
#include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
#endif
#define __ masm->
address ShenandoahBarrierSetAssembler::_shenandoah_lrb = NULL;
void ShenandoahBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
Register src, Register dst, Register count, RegSet saved_regs) {
if (is_oop) {
bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
if ((ShenandoahSATBBarrier && !dest_uninitialized) || ShenandoahIUBarrier || ShenandoahLoadRefBarrier) {
Label done;
// Avoid calling runtime if count == 0
__ cbz(count, done);
// Is GC active?
Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ ldrb(rscratch1, gc_state);
if (ShenandoahSATBBarrier && dest_uninitialized) {
__ tbz(rscratch1, ShenandoahHeap::HAS_FORWARDED_BITPOS, done);
} else {
__ mov(rscratch2, ShenandoahHeap::HAS_FORWARDED | ShenandoahHeap::MARKING);
__ tst(rscratch1, rscratch2);
__ br(Assembler::EQ, done);
}
__ push(saved_regs, sp);
if (UseCompressedOops) {
__ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::arraycopy_barrier_narrow_oop_entry), src, dst, count);
} else {
__ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::arraycopy_barrier_oop_entry), src, dst, count);
}
__ pop(saved_regs, sp);
__ bind(done);
}
}
}
void ShenandoahBarrierSetAssembler::shenandoah_write_barrier_pre(MacroAssembler* masm,
Register obj,
Register pre_val,
Register thread,
Register tmp,
bool tosca_live,
bool expand_call) {
if (ShenandoahSATBBarrier) {
satb_write_barrier_pre(masm, obj, pre_val, thread, tmp, tosca_live, expand_call);
}
}
void ShenandoahBarrierSetAssembler::satb_write_barrier_pre(MacroAssembler* masm,
Register obj,
Register pre_val,
Register thread,
Register tmp,
bool tosca_live,
bool expand_call) {
// If expand_call is true then we expand the call_VM_leaf macro
// directly to skip generating the check by
// InterpreterMacroAssembler::call_VM_leaf_base that checks _last_sp.
assert(thread == rthread, "must be");
Label done;
Label runtime;
assert_different_registers(obj, pre_val, tmp, rscratch1);
assert(pre_val != noreg && tmp != noreg, "expecting a register");
Address in_progress(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()));
Address index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
// Is marking active?
if (in_bytes(ShenandoahSATBMarkQueue::byte_width_of_active()) == 4) {
__ ldrw(tmp, in_progress);
} else {
assert(in_bytes(ShenandoahSATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
__ ldrb(tmp, in_progress);
}
__ cbzw(tmp, done);
// Do we need to load the previous value?
if (obj != noreg) {
__ load_heap_oop(pre_val, Address(obj, 0), noreg, noreg, AS_RAW);
}
// Is the previous value null?
__ cbz(pre_val, done);
// Can we store original value in the thread's buffer?
// Is index == 0?
// (The index field is typed as size_t.)
__ ldr(tmp, index); // tmp := *index_adr
__ cbz(tmp, runtime); // tmp == 0?
// If yes, goto runtime
__ sub(tmp, tmp, wordSize); // tmp := tmp - wordSize
__ str(tmp, index); // *index_adr := tmp
__ ldr(rscratch1, buffer);
__ add(tmp, tmp, rscratch1); // tmp := tmp + *buffer_adr
// Record the previous value
__ str(pre_val, Address(tmp, 0));
__ b(done);
__ bind(runtime);
// save the live input values
RegSet saved = RegSet::of(pre_val);
if (tosca_live) saved += RegSet::of(r0);
if (obj != noreg) saved += RegSet::of(obj);
__ push(saved, sp);
// Calling the runtime using the regular call_VM_leaf mechanism generates
// code (generated by InterpreterMacroAssember::call_VM_leaf_base)
// that checks that the *(rfp+frame::interpreter_frame_last_sp) == NULL.
//
// If we care generating the pre-barrier without a frame (e.g. in the
// intrinsified Reference.get() routine) then ebp might be pointing to
// the caller frame and so this check will most likely fail at runtime.
//
// Expanding the call directly bypasses the generation of the check.
// So when we do not have have a full interpreter frame on the stack
// expand_call should be passed true.
if (expand_call) {
assert(pre_val != c_rarg1, "smashed arg");
__ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
} else {
__ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
}
__ pop(saved, sp);
__ bind(done);
}
void ShenandoahBarrierSetAssembler::resolve_forward_pointer(MacroAssembler* masm, Register dst, Register tmp) {
assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled");
Label is_null;
__ cbz(dst, is_null);
resolve_forward_pointer_not_null(masm, dst, tmp);
__ bind(is_null);
}
// IMPORTANT: This must preserve all registers, even rscratch1 and rscratch2, except those explicitely
// passed in.
void ShenandoahBarrierSetAssembler::resolve_forward_pointer_not_null(MacroAssembler* masm, Register dst, Register tmp) {
assert(ShenandoahLoadRefBarrier || ShenandoahCASBarrier, "Should be enabled");
// The below loads the mark word, checks if the lowest two bits are
// set, and if so, clear the lowest two bits and copy the result
// to dst. Otherwise it leaves dst alone.
// Implementing this is surprisingly awkward. I do it here by:
// - Inverting the mark word
// - Test lowest two bits == 0
// - If so, set the lowest two bits
// - Invert the result back, and copy to dst
bool borrow_reg = (tmp == noreg);
if (borrow_reg) {
// No free registers available. Make one useful.
tmp = rscratch1;
if (tmp == dst) {
tmp = rscratch2;
}
__ push(RegSet::of(tmp), sp);
}
assert_different_registers(tmp, dst);
Label done;
__ ldr(tmp, Address(dst, oopDesc::mark_offset_in_bytes()));
__ eon(tmp, tmp, zr);
__ ands(zr, tmp, markOop::lock_mask_in_place);
__ br(Assembler::NE, done);
__ orr(tmp, tmp, markOop::marked_value);
__ eon(dst, tmp, zr);
__ bind(done);
if (borrow_reg) {
__ pop(RegSet::of(tmp), sp);
}
}
void ShenandoahBarrierSetAssembler::load_reference_barrier_not_null(MacroAssembler* masm, Register dst, Address load_addr) {
assert(ShenandoahLoadRefBarrier, "Should be enabled");
assert(dst != rscratch2, "need rscratch2");
assert_different_registers(load_addr.base(), load_addr.index(), rscratch1, rscratch2);
Label done;
__ enter();
Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ ldrb(rscratch2, gc_state);
// Check for heap stability
__ tbz(rscratch2, ShenandoahHeap::HAS_FORWARDED_BITPOS, done);
// use r1 for load address
Register result_dst = dst;
if (dst == r1) {
__ mov(rscratch1, dst);
dst = rscratch1;
}
// Save r0 and r1, unless it is an output register
RegSet to_save = RegSet::of(r0, r1) - result_dst;
__ push(to_save, sp);
__ lea(r1, load_addr);
__ mov(r0, dst);
__ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_lrb())));
__ mov(result_dst, r0);
__ pop(to_save, sp);
__ bind(done);
__ leave();
}
void ShenandoahBarrierSetAssembler::iu_barrier(MacroAssembler* masm, Register dst, Register tmp) {
if (ShenandoahIUBarrier) {
__ push_call_clobbered_registers();
satb_write_barrier_pre(masm, noreg, dst, rthread, tmp, true, false);
__ pop_call_clobbered_registers();
}
}
void ShenandoahBarrierSetAssembler::load_reference_barrier(MacroAssembler* masm, Register dst, Address load_addr) {
if (ShenandoahLoadRefBarrier) {
Label is_null;
__ cbz(dst, is_null);
load_reference_barrier_not_null(masm, dst, load_addr);
__ bind(is_null);
}
}
//
// Arguments:
//
// Inputs:
// src: oop location to load from, might be clobbered
//
// Output:
// dst: oop loaded from src location
//
// Kill:
// rscratch1 (scratch reg)
//
// Alias:
// dst: rscratch1 (might use rscratch1 as temporary output register to avoid clobbering src)
//
void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
Register dst, Address src, Register tmp1, Register tmp_thread) {
// 1: non-reference load, no additional barrier is needed
if (!is_reference_type(type)) {
BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
return;
}
// 2: load a reference from src location and apply LRB if needed
if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) {
Register result_dst = dst;
// Preserve src location for LRB
if (dst == src.base() || dst == src.index()) {
dst = rscratch1;
}
assert_different_registers(dst, src.base(), src.index());
BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
load_reference_barrier(masm, dst, src);
if (dst != result_dst) {
__ mov(result_dst, dst);
dst = result_dst;
}
} else {
BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
}
// 3: apply keep-alive barrier if needed
if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
__ enter();
__ push_call_clobbered_registers();
satb_write_barrier_pre(masm /* masm */,
noreg /* obj */,
dst /* pre_val */,
rthread /* thread */,
tmp1 /* tmp */,
true /* tosca_live */,
true /* expand_call */);
__ pop_call_clobbered_registers();
__ leave();
}
}
void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
Address dst, Register val, Register tmp1, Register tmp2) {
bool on_oop = type == T_OBJECT || type == T_ARRAY;
if (!on_oop) {
BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2);
return;
}
// flatten object address if needed
if (dst.index() == noreg && dst.offset() == 0) {
if (dst.base() != r3) {
__ mov(r3, dst.base());
}
} else {
__ lea(r3, dst);
}
shenandoah_write_barrier_pre(masm,
r3 /* obj */,
tmp2 /* pre_val */,
rthread /* thread */,
tmp1 /* tmp */,
val != noreg /* tosca_live */,
false /* expand_call */);
if (val == noreg) {
BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), noreg, noreg, noreg);
} else {
iu_barrier(masm, val, tmp1);
// G1 barrier needs uncompressed oop for region cross check.
Register new_val = val;
if (UseCompressedOops) {
new_val = rscratch2;
__ mov(new_val, val);
}
BarrierSetAssembler::store_at(masm, decorators, type, Address(r3, 0), val, noreg, noreg);
}
}
void ShenandoahBarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
Register obj, Register tmp, Label& slowpath) {
Label done;
// Resolve jobject
BarrierSetAssembler::try_resolve_jobject_in_native(masm, jni_env, obj, tmp, slowpath);
// Check for null.
__ cbz(obj, done);
assert(obj != rscratch2, "need rscratch2");
Address gc_state(jni_env, ShenandoahThreadLocalData::gc_state_offset() - JavaThread::jni_environment_offset());
__ lea(rscratch2, gc_state);
__ ldrb(rscratch2, Address(rscratch2));
// Check for heap in evacuation phase
__ tbnz(rscratch2, ShenandoahHeap::EVACUATION_BITPOS, slowpath);
__ bind(done);
}
// Special Shenandoah CAS implementation that handles false negatives due
// to concurrent evacuation. The service is more complex than a
// traditional CAS operation because the CAS operation is intended to
// succeed if the reference at addr exactly matches expected or if the
// reference at addr holds a pointer to a from-space object that has
// been relocated to the location named by expected. There are two
// races that must be addressed:
// a) A parallel thread may mutate the contents of addr so that it points
// to a different object. In this case, the CAS operation should fail.
// b) A parallel thread may heal the contents of addr, replacing a
// from-space pointer held in addr with the to-space pointer
// representing the new location of the object.
// Upon entry to cmpxchg_oop, it is assured that new_val equals NULL
// or it refers to an object that is not being evacuated out of
// from-space, or it refers to the to-space version of an object that
// is being evacuated out of from-space.
//
// By default the value held in the result register following execution
// of the generated code sequence is 0 to indicate failure of CAS,
// non-zero to indicate success. If is_cae, the result is the value most
// recently fetched from addr rather than a boolean success indicator.
//
// Clobbers rscratch1, rscratch2
void ShenandoahBarrierSetAssembler::cmpxchg_oop(MacroAssembler* masm,
Register addr,
Register expected,
Register new_val,
bool acquire, bool release,
bool is_cae,
Register result) {
Register tmp1 = rscratch1;
Register tmp2 = rscratch2;
bool is_narrow = UseCompressedOops;
Assembler::operand_size size = is_narrow ? Assembler::word : Assembler::xword;
assert_different_registers(addr, expected, tmp1, tmp2);
assert_different_registers(addr, new_val, tmp1, tmp2);
Label step4, done;
// There are two ways to reach this label. Initial entry into the
// cmpxchg_oop code expansion starts at step1 (which is equivalent
// to label step4). Additionally, in the rare case that four steps
// are required to perform the requested operation, the fourth step
// is the same as the first. On a second pass through step 1,
// control may flow through step 2 on its way to failure. It will
// not flow from step 2 to step 3 since we are assured that the
// memory at addr no longer holds a from-space pointer.
//
// The comments that immediately follow the step4 label apply only
// to the case in which control reaches this label by branch from
// step 3.
__ bind (step4);
// Step 4. CAS has failed because the value most recently fetched
// from addr is no longer the from-space pointer held in tmp2. If a
// different thread replaced the in-memory value with its equivalent
// to-space pointer, then CAS may still be able to succeed. The
// value held in the expected register has not changed.
//
// It is extremely rare we reach this point. For this reason, the
// implementation opts for smaller rather than potentially faster
// code. Ultimately, smaller code for this rare case most likely
// delivers higher overall throughput by enabling improved icache
// performance.
// Step 1. Fast-path.
//
// Try to CAS with given arguments. If successful, then we are done.
//
// No label required for step 1.
__ cmpxchg(addr, expected, new_val, size, acquire, release, false, tmp2);
// EQ flag set iff success. tmp2 holds value fetched.
// If expected equals null but tmp2 does not equal null, the
// following branches to done to report failure of CAS. If both
// expected and tmp2 equal null, the following branches to done to
// report success of CAS. There's no need for a special test of
// expected equal to null.
__ br(Assembler::EQ, done);
// if CAS failed, fall through to step 2
// Step 2. CAS has failed because the value held at addr does not
// match expected. This may be a false negative because the value fetched
// from addr (now held in tmp2) may be a from-space pointer to the
// original copy of same object referenced by to-space pointer expected.
//
// To resolve this, it suffices to find the forward pointer associated
// with fetched value. If this matches expected, retry CAS with new
// parameters. If this mismatches, then we have a legitimate
// failure, and we're done.
//
// No need for step2 label.
// overwrite tmp1 with from-space pointer fetched from memory
__ mov(tmp1, tmp2);
if (is_narrow) {
// Decode tmp1 in order to resolve its forward pointer
__ decode_heap_oop(tmp1, tmp1);
}
resolve_forward_pointer(masm, tmp1);
// Encode tmp1 to compare against expected.
__ encode_heap_oop(tmp1, tmp1);
// Does forwarded value of fetched from-space pointer match original
// value of expected? If tmp1 holds null, this comparison will fail
// because we know from step1 that expected is not null. There is
// no need for a separate test for tmp1 (the value originally held
// in memory) equal to null.
__ cmp(tmp1, expected);
// If not, then the failure was legitimate and we're done.
// Branching to done with NE condition denotes failure.
__ br(Assembler::NE, done);
// Fall through to step 3. No need for step3 label.
// Step 3. We've confirmed that the value originally held in memory
// (now held in tmp2) pointed to from-space version of original
// expected value. Try the CAS again with the from-space expected
// value. If it now succeeds, we're good.
//
// Note: tmp2 holds encoded from-space pointer that matches to-space
// object residing at expected. tmp2 is the new "expected".
// Note that macro implementation of __cmpxchg cannot use same register
// tmp2 for result and expected since it overwrites result before it
// compares result with expected.
__ cmpxchg(addr, tmp2, new_val, size, acquire, release, false, noreg);
// EQ flag set iff success. tmp2 holds value fetched, tmp1 (rscratch1) clobbered.
// If fetched value did not equal the new expected, this could
// still be a false negative because some other thread may have
// newly overwritten the memory value with its to-space equivalent.
__ br(Assembler::NE, step4);
if (is_cae) {
// We're falling through to done to indicate success. Success
// with is_cae is denoted by returning the value of expected as
// result.
__ mov(tmp2, expected);
}
__ bind(done);
// At entry to done, the Z (EQ) flag is on iff if the CAS
// operation was successful. Additionally, if is_cae, tmp2 holds
// the value most recently fetched from addr. In this case, success
// is denoted by tmp2 matching expected.
if (is_cae) {
__ mov(result, tmp2);
} else {
__ cset(result, Assembler::EQ);
}
}
#undef __
#ifdef COMPILER1
#define __ ce->masm()->
void ShenandoahBarrierSetAssembler::gen_pre_barrier_stub(LIR_Assembler* ce, ShenandoahPreBarrierStub* stub) {
ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
// At this point we know that marking is in progress.
// If do_load() is true then we have to emit the
// load of the previous value; otherwise it has already
// been loaded into _pre_val.
__ bind(*stub->entry());
assert(stub->pre_val()->is_register(), "Precondition.");
Register pre_val_reg = stub->pre_val()->as_register();
if (stub->do_load()) {
ce->mem2reg(stub->addr(), stub->pre_val(), T_OBJECT, stub->patch_code(), stub->info(), false /*wide*/, false /*unaligned*/);
}
__ cbz(pre_val_reg, *stub->continuation());
ce->store_parameter(stub->pre_val()->as_register(), 0);
__ far_call(RuntimeAddress(bs->pre_barrier_c1_runtime_code_blob()->code_begin()));
__ b(*stub->continuation());
}
void ShenandoahBarrierSetAssembler::gen_load_reference_barrier_stub(LIR_Assembler* ce, ShenandoahLoadReferenceBarrierStub* stub) {
ShenandoahBarrierSetC1* bs = (ShenandoahBarrierSetC1*)BarrierSet::barrier_set()->barrier_set_c1();
__ bind(*stub->entry());
Register obj = stub->obj()->as_register();
Register res = stub->result()->as_register();
Register addr = stub->addr()->as_pointer_register();
Register tmp1 = stub->tmp1()->as_register();
Register tmp2 = stub->tmp2()->as_register();
assert(res == r0, "result must arrive in r0");
if (res != obj) {
__ mov(res, obj);
}
// Check for null.
__ cbz(res, *stub->continuation());
// Check for object in cset.
__ mov(tmp2, ShenandoahHeap::in_cset_fast_test_addr());
__ lsr(tmp1, res, ShenandoahHeapRegion::region_size_bytes_shift_jint());
__ ldrb(tmp2, Address(tmp2, tmp1));
__ cbz(tmp2, *stub->continuation());
// Check if object is already forwarded.
Label slow_path;
__ ldr(tmp1, Address(res, oopDesc::mark_offset_in_bytes()));
__ eon(tmp1, tmp1, zr);
__ ands(zr, tmp1, markOop::lock_mask_in_place);
__ br(Assembler::NE, slow_path);
// Decode forwarded object.
__ orr(tmp1, tmp1, markOop::marked_value);
__ eon(res, tmp1, zr);
__ b(*stub->continuation());
__ bind(slow_path);
ce->store_parameter(res, 0);
ce->store_parameter(addr, 1);
__ far_call(RuntimeAddress(bs->load_reference_barrier_rt_code_blob()->code_begin()));
__ b(*stub->continuation());
}
#undef __
#define __ sasm->
void ShenandoahBarrierSetAssembler::generate_c1_pre_barrier_runtime_stub(StubAssembler* sasm) {
__ prologue("shenandoah_pre_barrier", false);
// arg0 : previous value of memory
BarrierSet* bs = BarrierSet::barrier_set();
const Register pre_val = r0;
const Register thread = rthread;
const Register tmp = rscratch1;
Address queue_index(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()));
Address buffer(thread, in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()));
Label done;
Label runtime;
// Is marking still active?
Address gc_state(thread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
__ ldrb(tmp, gc_state);
__ tbz(tmp, ShenandoahHeap::MARKING_BITPOS, done);
// Can we store original value in the thread's buffer?
__ ldr(tmp, queue_index);
__ cbz(tmp, runtime);
__ sub(tmp, tmp, wordSize);
__ str(tmp, queue_index);
__ ldr(rscratch2, buffer);
__ add(tmp, tmp, rscratch2);
__ load_parameter(0, rscratch2);
__ str(rscratch2, Address(tmp, 0));
__ b(done);
__ bind(runtime);
__ push_call_clobbered_registers();
__ load_parameter(0, pre_val);
__ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), pre_val, thread);
__ pop_call_clobbered_registers();
__ bind(done);
__ epilogue();
}
void ShenandoahBarrierSetAssembler::generate_c1_load_reference_barrier_runtime_stub(StubAssembler* sasm) {
__ prologue("shenandoah_load_reference_barrier", false);
// arg0 : object to be resolved
__ push_call_clobbered_registers();
__ load_parameter(0, r0);
__ load_parameter(1, r1);
if (UseCompressedOops) {
__ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow));
} else {
__ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier));
}
__ blr(lr);
__ mov(rscratch1, r0);
__ pop_call_clobbered_registers();
__ mov(r0, rscratch1);
__ epilogue();
}
#undef __
#endif // COMPILER1
address ShenandoahBarrierSetAssembler::shenandoah_lrb() {
assert(_shenandoah_lrb != NULL, "need load reference barrier stub");
return _shenandoah_lrb;
}
#define __ cgen->assembler()->
// Shenandoah load reference barrier.
//
// Input:
// r0: OOP to evacuate. Not null.
// r1: load address
//
// Output:
// r0: Pointer to evacuated OOP.
//
// Trash rscratch1, rscratch2. Preserve everything else.
address ShenandoahBarrierSetAssembler::generate_shenandoah_lrb(StubCodeGenerator* cgen) {
__ align(6);
StubCodeMark mark(cgen, "StubRoutines", "shenandoah_lrb");
address start = __ pc();
Label slow_path;
__ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr());
__ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint());
__ ldrb(rscratch2, Address(rscratch2, rscratch1));
__ tbnz(rscratch2, 0, slow_path);
__ ret(lr);
__ bind(slow_path);
__ enter(); // required for proper stackwalking of RuntimeStub frame
__ push_call_clobbered_registers();
if (UseCompressedOops) {
__ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_narrow));
} else {
__ mov(lr, CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier));
}
__ blr(lr);
__ mov(rscratch1, r0);
__ pop_call_clobbered_registers();
__ mov(r0, rscratch1);
__ leave(); // required for proper stackwalking of RuntimeStub frame
__ ret(lr);
return start;
}
#undef __
void ShenandoahBarrierSetAssembler::barrier_stubs_init() {
if (ShenandoahLoadRefBarrier) {
int stub_code_size = 2048;
ResourceMark rm;
BufferBlob* bb = BufferBlob::create("shenandoah_barrier_stubs", stub_code_size);
CodeBuffer buf(bb);
StubCodeGenerator cgen(&buf);
_shenandoah_lrb = generate_shenandoah_lrb(&cgen);
}
}