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[liftoff][arm] GetUnusedRegister before Acquire

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Ensure that GetUnusedRegister is always called before
acquiring the scratch register in case it is needed
for spilling the value of the used register.

Bug: v8:6600, chromium:910824
Change-Id: I93ae684ad504584807dfa6227b6af14609c6bcf5
Reviewed-on: https://chromium-review.googlesource.com/c/1387498
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58442}
This commit is contained in:
George Wort 2018-12-21 14:02:37 +00:00 committed by Commit Bot
parent 37273c5aac
commit 491eff86b5
2 changed files with 64 additions and 32 deletions
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59
src/wasm/baseline/arm/liftoff-assembler-arm.h
View File

@ -316,12 +316,8 @@ void LiftoffAssembler::Load(LiftoffRegister dst, Register src_addr,
} else {
// TODO(arm): Use vld1 for f32 when implemented in simulator as used for
// f64. It supports unaligned access.
Register scratch = no_reg;
if (temps.CanAcquire()) {
scratch = temps.Acquire();
} else {
scratch = GetUnusedRegister(kGpReg, pinned).gp();
}
Register scratch =
(actual_src_addr == src_addr) ? temps.Acquire() : actual_src_addr;
ldr(scratch, MemOperand(actual_src_addr));
vmov(liftoff::GetFloatRegister(dst.fp()), scratch);
}
@ -400,26 +396,25 @@ void LiftoffAssembler::Store(Register dst_addr, Register offset_reg,
return;
}
UseScratchRegisterScope temps(this);
if (type.value() == StoreType::kF64Store ||
type.value() == StoreType::kF32Store) {
if (type.value() == StoreType::kF64Store) {
Register actual_dst_addr = liftoff::CalculateActualAddress(
this, &temps, dst_addr, offset_reg, offset_imm);
if (type.value() == StoreType::kF64Store) {
// Armv6 is not supported so Neon can be used to avoid alignment issues.
CpuFeatureScope scope(this, NEON);
vst1(Neon64, NeonListOperand(src.fp()), NeonMemOperand(actual_dst_addr));
} else {
// TODO(arm): Use vst1 for f32 when implemented in simulator as used for
// f64. It supports unaligned access.
Register scratch = no_reg;
if (temps.CanAcquire()) {
scratch = temps.Acquire();
} else {
scratch = GetUnusedRegister(kGpReg, pinned).gp();
}
vmov(scratch, liftoff::GetFloatRegister(src.fp()));
str(scratch, MemOperand(actual_dst_addr));
}
// Armv6 is not supported so Neon can be used to avoid alignment issues.
CpuFeatureScope scope(this, NEON);
vst1(Neon64, NeonListOperand(src.fp()), NeonMemOperand(actual_dst_addr));
} else if (type.value() == StoreType::kF32Store) {
// TODO(arm): Use vst1 for f32 when implemented in simulator as used for
// f64. It supports unaligned access.
// CalculateActualAddress will only not use a scratch register if the
// following condition holds, otherwise another register must be
// retrieved.
Register scratch = (offset_reg == no_reg && offset_imm == 0)
? temps.Acquire()
: GetUnusedRegister(kGpReg, pinned).gp();
Register actual_dst_addr = liftoff::CalculateActualAddress(
this, &temps, dst_addr, offset_reg, offset_imm);
vmov(scratch, liftoff::GetFloatRegister(src.fp()));
str(scratch, MemOperand(actual_dst_addr));
} else {
MemOperand dst_op =
liftoff::GetMemOp(this, &temps, dst_addr, offset_reg, offset_imm);
@ -671,13 +666,13 @@ bool LiftoffAssembler::emit_i32_ctz(Register dst, Register src) {
bool LiftoffAssembler::emit_i32_popcnt(Register dst, Register src) {
{
UseScratchRegisterScope temps(this);
Register scratch = temps.Acquire();
LiftoffRegList pinned;
pinned.set(dst);
Register scratch = GetUnusedRegister(kGpReg, pinned).gp();
Register scratch_2 = temps.Acquire();
// x = x - ((x & (0x55555555 << 1)) >> 1)
and_(scratch, src, Operand(0xaaaaaaaa));
sub(dst, src, Operand(scratch, LSR, 1));
LiftoffRegList pinned;
pinned.set(dst);
Register scratch_2 = GetUnusedRegister(kGpReg, pinned).gp();
// x = (x & 0x33333333) + ((x & (0x33333333 << 2)) >> 2)
mov(scratch, Operand(0x33333333));
and_(scratch_2, dst, Operand(scratch, LSL, 2));
@ -970,8 +965,8 @@ void LiftoffAssembler::emit_f32_copysign(DoubleRegister dst, DoubleRegister lhs,
DoubleRegister rhs) {
constexpr uint32_t kF32SignBit = uint32_t{1} << 31;
UseScratchRegisterScope temps(this);
Register scratch = temps.Acquire();
Register scratch2 = GetUnusedRegister(kGpReg).gp();
Register scratch = GetUnusedRegister(kGpReg).gp();
Register scratch2 = temps.Acquire();
VmovLow(scratch, lhs);
// Clear sign bit in {scratch}.
bic(scratch, scratch, Operand(kF32SignBit));
@ -989,8 +984,8 @@ void LiftoffAssembler::emit_f64_copysign(DoubleRegister dst, DoubleRegister lhs,
// On arm, we cannot hold the whole f64 value in a gp register, so we just
// operate on the upper half (UH).
UseScratchRegisterScope temps(this);
Register scratch = temps.Acquire();
Register scratch2 = GetUnusedRegister(kGpReg).gp();
Register scratch = GetUnusedRegister(kGpReg).gp();
Register scratch2 = temps.Acquire();
VmovHigh(scratch, lhs);
// Clear sign bit in {scratch}.
bic(scratch, scratch, Operand(kF64SignBitHighWord));

37
test/mjsunit/regress/wasm/regress-910824.js Normal file
View File

@ -0,0 +1,37 @@
// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
load('test/mjsunit/wasm/wasm-constants.js');
load('test/mjsunit/wasm/wasm-module-builder.js');
const builder = new WasmModuleBuilder();
builder.addGlobal(kWasmI32, 1);
builder.addGlobal(kWasmF32, 1);
builder.addType(makeSig([kWasmI32, kWasmF32, kWasmF32, kWasmF64], [kWasmI32]));
builder.addFunction(undefined, 0 /* sig */)
.addLocals({i32_count: 504})
.addBody([
kExprGetGlobal, 0x00,
kExprSetLocal, 0x04,
kExprGetLocal, 0x04,
kExprI32Const, 0x01,
kExprI32Sub,
kExprGetGlobal, 0x00,
kExprI32Const, 0x00,
kExprI32Eqz,
kExprGetGlobal, 0x00,
kExprI32Const, 0x01,
kExprI32Const, 0x01,
kExprI32Sub,
kExprGetGlobal, 0x00,
kExprI32Const, 0x00,
kExprI32Eqz,
kExprGetGlobal, 0x00,
kExprI32Const, 0x00,
kExprI32Const, 0x01,
kExprI32Sub,
kExprGetGlobal, 0x01,
kExprUnreachable,
]);
builder.instantiate();