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[ARM64] Change TruncateInt64ToInt32 to a NOP.

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BUG=

Review-Url: https://codereview.chromium.org/2240803003
Cr-Commit-Position: refs/heads/master@{#38612}
This commit is contained in:
georgia.kouveli 2016-08-12 04:29:51 -07:00 committed by Commit bot
parent d252808011
commit 227353b76a
2 changed files with 9 additions and 16 deletions
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15
src/compiler/arm64/instruction-selector-arm64.cc
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@ -1671,18 +1671,9 @@ void InstructionSelector::VisitRoundFloat64ToInt32(Node* node) {
void InstructionSelector::VisitTruncateInt64ToInt32(Node* node) {
Arm64OperandGenerator g(this);
Node* value = node->InputAt(0);
if (CanCover(node, value) && value->InputCount() >= 2) {
Int64BinopMatcher m(value);
if ((m.IsWord64Sar() && m.right().HasValue() &&
(m.right().Value() == 32)) ||
(m.IsWord64Shr() && m.right().IsInRange(32, 63))) {
Emit(kArm64Lsr, g.DefineAsRegister(node), g.UseRegister(m.left().node()),
g.UseImmediate(m.right().node()));
return;
}
}
Emit(kArm64Mov32, g.DefineAsRegister(node), g.UseRegister(node->InputAt(0)));
// The top 32 bits in the 64-bit register will be undefined, and
// must not be used by a dependent node.
Emit(kArchNop, g.DefineSameAsFirst(node), g.UseRegister(value));
}

10
test/unittests/compiler/arm64/instruction-selector-arm64-unittest.cc
View File

@ -314,7 +314,7 @@ const Conversion kConversionInstructions[] = {
kArm64Mov32, MachineType::Uint64()},
MachineType::Uint32()},
{{&RawMachineAssembler::TruncateInt64ToInt32, "TruncateInt64ToInt32",
kArm64Mov32, MachineType::Int32()},
kArchNop, MachineType::Int32()},
MachineType::Int64()},
{{&RawMachineAssembler::ChangeInt32ToFloat64, "ChangeInt32ToFloat64",
kArm64Int32ToFloat64, MachineType::Float64()},
@ -1799,12 +1799,11 @@ TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithWord64Sar) {
m.Return(t);
Stream s = m.Build();
ASSERT_EQ(1U, s.size());
EXPECT_EQ(kArm64Lsr, s[0]->arch_opcode());
EXPECT_EQ(kArm64Asr, s[0]->arch_opcode());
ASSERT_EQ(2U, s[0]->InputCount());
EXPECT_EQ(s.ToVreg(p), s.ToVreg(s[0]->InputAt(0)));
EXPECT_EQ(32, s.ToInt64(s[0]->InputAt(1)));
ASSERT_EQ(1U, s[0]->OutputCount());
EXPECT_EQ(s.ToVreg(t), s.ToVreg(s[0]->OutputAt(0)));
}
@ -1821,7 +1820,6 @@ TEST_F(InstructionSelectorTest, TruncateInt64ToInt32WithWord64Shr) {
EXPECT_EQ(s.ToVreg(p), s.ToVreg(s[0]->InputAt(0)));
EXPECT_EQ(x, s.ToInt64(s[0]->InputAt(1)));
ASSERT_EQ(1U, s[0]->OutputCount());
EXPECT_EQ(s.ToVreg(t), s.ToVreg(s[0]->OutputAt(0)));
}
}
@ -2319,6 +2317,10 @@ TEST_P(InstructionSelectorConversionTest, Parameter) {
StreamBuilder m(this, conv.mi.machine_type, conv.src_machine_type);
m.Return((m.*conv.mi.constructor)(m.Parameter(0)));
Stream s = m.Build();
if (conv.mi.arch_opcode == kArchNop) {
ASSERT_EQ(0U, s.size());
return;
}
ASSERT_EQ(1U, s.size());
EXPECT_EQ(conv.mi.arch_opcode, s[0]->arch_opcode());
EXPECT_EQ(1U, s[0]->InputCount());