From 9e0be36948831146ca9a830fd5f4cf6876cf8827 Mon Sep 17 00:00:00 2001 From: "fschneider@chromium.org" Date: Tue, 10 Jan 2012 16:06:32 +0000 Subject: [PATCH] Avoid recording unnecessary deoptimization environments in a couple of places. This reduces the number of uses and potentially shortens live ranges. Review URL: http://codereview.chromium.org/8983018 git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10370 ce2b1a6d-e550-0410-aec6-3dcde31c8c00 --- src/arm/lithium-arm.cc | 29 ++++++++++++++++++++++------- src/ia32/lithium-ia32.cc | 32 +++++++++++++++++++++++--------- src/mips/lithium-mips.cc | 29 ++++++++++++++++++++++------- src/runtime.cc | 1 - src/x64/lithium-x64.cc | 32 +++++++++++++++++++++++--------- 5 files changed, 90 insertions(+), 33 deletions(-) diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc index b001eca..7b66311 100644 --- a/src/arm/lithium-arm.cc +++ b/src/arm/lithium-arm.cc @@ -1038,14 +1038,23 @@ LInstruction* LChunkBuilder::DoGoto(HGoto* instr) { LInstruction* LChunkBuilder::DoBranch(HBranch* instr) { - HValue* v = instr->value(); - if (v->EmitAtUses()) { - HBasicBlock* successor = HConstant::cast(v)->ToBoolean() + HValue* value = instr->value(); + if (value->EmitAtUses()) { + HBasicBlock* successor = HConstant::cast(value)->ToBoolean() ? instr->FirstSuccessor() : instr->SecondSuccessor(); return new LGoto(successor->block_id()); } - return AssignEnvironment(new LBranch(UseRegister(v))); + + LBranch* result = new LBranch(UseRegister(value)); + // Tagged values that are not known smis or booleans require a + // deoptimization environment. + Representation rep = value->representation(); + HType type = value->type(); + if (rep.IsTagged() && !type.IsSmi() && !type.IsBoolean()) { + return AssignEnvironment(result); + } + return result; } @@ -1344,7 +1353,12 @@ LInstruction* LChunkBuilder::DoMul(HMul* instr) { } else { left = UseRegisterAtStart(instr->LeastConstantOperand()); } - return AssignEnvironment(DefineAsRegister(new LMulI(left, right, temp))); + LMulI* mul = new LMulI(left, right, temp); + if (instr->CheckFlag(HValue::kCanOverflow) || + instr->CheckFlag(HValue::kBailoutOnMinusZero)) { + AssignEnvironment(mul); + } + return DefineAsRegister(mul); } else if (instr->representation().IsDouble()) { return DoArithmeticD(Token::MUL, instr); @@ -1556,7 +1570,7 @@ LInstruction* LChunkBuilder::DoElementsKind(HElementsKind* instr) { LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) { LOperand* object = UseRegister(instr->value()); LValueOf* result = new LValueOf(object, TempRegister()); - return AssignEnvironment(DefineAsRegister(result)); + return DefineAsRegister(result); } @@ -1874,7 +1888,8 @@ LInstruction* LChunkBuilder::DoLoadKeyedFastElement( LOperand* obj = UseRegisterAtStart(instr->object()); LOperand* key = UseRegisterAtStart(instr->key()); LLoadKeyedFastElement* result = new LLoadKeyedFastElement(obj, key); - return AssignEnvironment(DefineAsRegister(result)); + if (instr->RequiresHoleCheck()) AssignEnvironment(result); + return DefineAsRegister(result); } diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc index 5cd276f..6ecb29f 100644 --- a/src/ia32/lithium-ia32.cc +++ b/src/ia32/lithium-ia32.cc @@ -1047,22 +1047,31 @@ LInstruction* LChunkBuilder::DoGoto(HGoto* instr) { LInstruction* LChunkBuilder::DoBranch(HBranch* instr) { - HValue* v = instr->value(); - if (v->EmitAtUses()) { - ASSERT(v->IsConstant()); - ASSERT(!v->representation().IsDouble()); - HBasicBlock* successor = HConstant::cast(v)->ToBoolean() + HValue* value = instr->value(); + if (value->EmitAtUses()) { + ASSERT(value->IsConstant()); + ASSERT(!value->representation().IsDouble()); + HBasicBlock* successor = HConstant::cast(value)->ToBoolean() ? instr->FirstSuccessor() : instr->SecondSuccessor(); return new(zone()) LGoto(successor->block_id()); } + + // Untagged integers or doubles, smis and booleans don't require a + // deoptimization environment nor a temp register. + Representation rep = value->representation(); + HType type = value->type(); + if (!rep.IsTagged() || type.IsSmi() || type.IsBoolean()) { + return new(zone()) LBranch(UseRegister(value), NULL); + } + ToBooleanStub::Types expected = instr->expected_input_types(); // We need a temporary register when we have to access the map *or* we have // no type info yet, in which case we handle all cases (including the ones // involving maps). bool needs_temp = expected.NeedsMap() || expected.IsEmpty(); LOperand* temp = needs_temp ? TempRegister() : NULL; - return AssignEnvironment(new(zone()) LBranch(UseRegister(v), temp)); + return AssignEnvironment(new(zone()) LBranch(UseRegister(value), temp)); } @@ -1388,7 +1397,11 @@ LInstruction* LChunkBuilder::DoMul(HMul* instr) { temp = TempRegister(); } LMulI* mul = new(zone()) LMulI(left, right, temp); - return AssignEnvironment(DefineSameAsFirst(mul)); + if (instr->CheckFlag(HValue::kCanOverflow) || + instr->CheckFlag(HValue::kBailoutOnMinusZero)) { + AssignEnvironment(mul); + } + return DefineSameAsFirst(mul); } else if (instr->representation().IsDouble()) { return DoArithmeticD(Token::MUL, instr); } else { @@ -1616,7 +1629,7 @@ LInstruction* LChunkBuilder::DoElementsKind(HElementsKind* instr) { LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) { LOperand* object = UseRegister(instr->value()); LValueOf* result = new(zone()) LValueOf(object, TempRegister()); - return AssignEnvironment(DefineSameAsFirst(result)); + return DefineSameAsFirst(result); } @@ -1956,7 +1969,8 @@ LInstruction* LChunkBuilder::DoLoadKeyedFastElement( LOperand* obj = UseRegisterAtStart(instr->object()); LOperand* key = UseRegisterOrConstantAtStart(instr->key()); LLoadKeyedFastElement* result = new(zone()) LLoadKeyedFastElement(obj, key); - return AssignEnvironment(DefineAsRegister(result)); + if (instr->RequiresHoleCheck()) AssignEnvironment(result); + return DefineAsRegister(result); } diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc index 634b706..90e1024 100644 --- a/src/mips/lithium-mips.cc +++ b/src/mips/lithium-mips.cc @@ -1038,14 +1038,23 @@ LInstruction* LChunkBuilder::DoGoto(HGoto* instr) { LInstruction* LChunkBuilder::DoBranch(HBranch* instr) { - HValue* v = instr->value(); - if (v->EmitAtUses()) { - HBasicBlock* successor = HConstant::cast(v)->ToBoolean() + HValue* value = instr->value(); + if (value->EmitAtUses()) { + HBasicBlock* successor = HConstant::cast(value)->ToBoolean() ? instr->FirstSuccessor() : instr->SecondSuccessor(); return new LGoto(successor->block_id()); } - return AssignEnvironment(new LBranch(UseRegister(v))); + + LBranch* result = new LBranch(UseRegister(value)); + // Tagged values that are not known smis or booleans require a + // deoptimization environment. + Representation rep = value->representation(); + HType type = value->type(); + if (rep.IsTagged() && !type.IsSmi() && !type.IsBoolean()) { + return AssignEnvironment(result); + } + return result; } @@ -1345,7 +1354,12 @@ LInstruction* LChunkBuilder::DoMul(HMul* instr) { } else { left = UseRegisterAtStart(instr->LeastConstantOperand()); } - return AssignEnvironment(DefineAsRegister(new LMulI(left, right, temp))); + LMulI* mul = new LMulI(left, right, temp); + if (instr->CheckFlag(HValue::kCanOverflow) || + instr->CheckFlag(HValue::kBailoutOnMinusZero)) { + AssignEnvironment(mul); + } + return DefineAsRegister(mul); } else if (instr->representation().IsDouble()) { return DoArithmeticD(Token::MUL, instr); @@ -1558,7 +1572,7 @@ LInstruction* LChunkBuilder::DoElementsKind(HElementsKind* instr) { LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) { LOperand* object = UseRegister(instr->value()); LValueOf* result = new LValueOf(object, TempRegister()); - return AssignEnvironment(DefineAsRegister(result)); + return DefineAsRegister(result); } @@ -1877,7 +1891,8 @@ LInstruction* LChunkBuilder::DoLoadKeyedFastElement( LOperand* obj = UseRegisterAtStart(instr->object()); LOperand* key = UseRegisterAtStart(instr->key()); LLoadKeyedFastElement* result = new LLoadKeyedFastElement(obj, key); - return AssignEnvironment(DefineAsRegister(result)); + if (instr->RequiresHoleCheck()) AssignEnvironment(result); + return DefineAsRegister(result); } diff --git a/src/runtime.cc b/src/runtime.cc index 90697b6..163c066 100644 --- a/src/runtime.cc +++ b/src/runtime.cc @@ -431,7 +431,6 @@ static Handle CreateObjectLiteralBoilerplate( static const int kSmiOnlyLiteralMinimumLength = 1024; -// static Handle Runtime::CreateArrayLiteralBoilerplate( Isolate* isolate, Handle literals, diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc index 5bae14b..d0a5a41 100644 --- a/src/x64/lithium-x64.cc +++ b/src/x64/lithium-x64.cc @@ -1033,16 +1033,25 @@ LInstruction* LChunkBuilder::DoGoto(HGoto* instr) { LInstruction* LChunkBuilder::DoBranch(HBranch* instr) { - HValue* v = instr->value(); - if (v->EmitAtUses()) { - ASSERT(v->IsConstant()); - ASSERT(!v->representation().IsDouble()); - HBasicBlock* successor = HConstant::cast(v)->ToBoolean() + HValue* value = instr->value(); + if (value->EmitAtUses()) { + ASSERT(value->IsConstant()); + ASSERT(!value->representation().IsDouble()); + HBasicBlock* successor = HConstant::cast(value)->ToBoolean() ? instr->FirstSuccessor() : instr->SecondSuccessor(); return new LGoto(successor->block_id()); } - return AssignEnvironment(new LBranch(UseRegister(v))); + + LBranch* result = new LBranch(UseRegister(value)); + // Tagged values that are not known smis or booleans require a + // deoptimization environment. + Representation rep = value->representation(); + HType type = value->type(); + if (rep.IsTagged() && !type.IsSmi() && !type.IsBoolean()) { + return AssignEnvironment(result); + } + return result; } @@ -1329,7 +1338,11 @@ LInstruction* LChunkBuilder::DoMul(HMul* instr) { LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand()); LOperand* right = UseOrConstant(instr->MostConstantOperand()); LMulI* mul = new LMulI(left, right); - return AssignEnvironment(DefineSameAsFirst(mul)); + if (instr->CheckFlag(HValue::kCanOverflow) || + instr->CheckFlag(HValue::kBailoutOnMinusZero)) { + AssignEnvironment(mul); + } + return DefineSameAsFirst(mul); } else if (instr->representation().IsDouble()) { return DoArithmeticD(Token::MUL, instr); } else { @@ -1553,7 +1566,7 @@ LInstruction* LChunkBuilder::DoElementsKind(HElementsKind* instr) { LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) { LOperand* object = UseRegister(instr->value()); LValueOf* result = new LValueOf(object); - return AssignEnvironment(DefineSameAsFirst(result)); + return DefineSameAsFirst(result); } @@ -1866,7 +1879,8 @@ LInstruction* LChunkBuilder::DoLoadKeyedFastElement( LOperand* obj = UseRegisterAtStart(instr->object()); LOperand* key = UseRegisterOrConstantAtStart(instr->key()); LLoadKeyedFastElement* result = new LLoadKeyedFastElement(obj, key); - return AssignEnvironment(DefineAsRegister(result)); + if (instr->RequiresHoleCheck()) AssignEnvironment(result); + return DefineAsRegister(result); } -- 2.7.4