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[wasm][liftoff][arm] Record correct offset in StoreTaggedPointer

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The write barrier for storing a reference to an object requires the
destination offset as a parameter. The existing code only passed the
immediate offset, however, not the offset provided through a register.
With this CL, the correct offset is provided.

R=thibaudm@chromium.org

Bug: v8:7581
Change-Id: Ia2a1d90d822988a3ef0c27ce8227f28f0226c937
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2639766
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72194}
This commit is contained in:
Andreas Haas 2021-01-20 14:31:53 +01:00 committed by Commit Bot
parent 14ad529b46
commit a1616e6f7f
1 changed files with 15 additions and 8 deletions
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23
src/wasm/baseline/arm/liftoff-assembler-arm.h
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@ -703,13 +703,17 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
LiftoffRegister src,
LiftoffRegList pinned) {
STATIC_ASSERT(kTaggedSize == kInt32Size);
{
// Store the value.
UseScratchRegisterScope temps(this);
MemOperand dst_op =
liftoff::GetMemOp(this, &temps, dst_addr, offset_reg, offset_imm);
str(src.gp(), dst_op);
Register actual_offset_reg = offset_reg;
if (offset_reg != no_reg && offset_imm != 0) {
if (cache_state()->is_used(LiftoffRegister(offset_reg))) {
actual_offset_reg = GetUnusedRegister(kGpReg, pinned).gp();
}
add(actual_offset_reg, offset_reg, Operand(offset_imm));
}
MemOperand dst_op = actual_offset_reg == no_reg
? MemOperand(dst_addr, offset_imm)
: MemOperand(dst_addr, actual_offset_reg);
str(src.gp(), dst_op);
// The write barrier.
Label write_barrier;
Label exit;
@ -720,8 +724,11 @@ void LiftoffAssembler::StoreTaggedPointer(Register dst_addr,
JumpIfSmi(src.gp(), &exit);
CheckPageFlag(src.gp(), MemoryChunk::kPointersToHereAreInterestingMask, eq,
&exit);
CallRecordWriteStub(dst_addr, Operand(offset_imm), EMIT_REMEMBERED_SET,
kSaveFPRegs, wasm::WasmCode::kRecordWrite);
CallRecordWriteStub(dst_addr,
actual_offset_reg == no_reg ? Operand(offset_imm)
: Operand(actual_offset_reg),
EMIT_REMEMBERED_SET, kSaveFPRegs,
wasm::WasmCode::kRecordWrite);
bind(&exit);
}