Revision: 10370
Author: [email protected]
Date: Tue Jan 10 08:06:32 2012
Log: 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
http://code.google.com/p/v8/source/detail?r=10370
Modified:
/branches/bleeding_edge/src/arm/lithium-arm.cc
/branches/bleeding_edge/src/ia32/lithium-ia32.cc
/branches/bleeding_edge/src/mips/lithium-mips.cc
/branches/bleeding_edge/src/runtime.cc
/branches/bleeding_edge/src/x64/lithium-x64.cc
=======================================
--- /branches/bleeding_edge/src/arm/lithium-arm.cc Thu Dec 22 08:23:47 2011
+++ /branches/bleeding_edge/src/arm/lithium-arm.cc Tue Jan 10 08:06:32 2012
@@ -1038,14 +1038,23 @@
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 @@
} 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::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 @@
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);
}
=======================================
--- /branches/bleeding_edge/src/ia32/lithium-ia32.cc Thu Dec 22 08:23:47
2011
+++ /branches/bleeding_edge/src/ia32/lithium-ia32.cc Tue Jan 10 08:06:32
2012
@@ -1047,22 +1047,31 @@
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 @@
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::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 @@
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);
}
=======================================
--- /branches/bleeding_edge/src/mips/lithium-mips.cc Thu Dec 22 08:23:47
2011
+++ /branches/bleeding_edge/src/mips/lithium-mips.cc Tue Jan 10 08:06:32
2012
@@ -1038,14 +1038,23 @@
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 @@
} 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::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 @@
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);
}
=======================================
--- /branches/bleeding_edge/src/runtime.cc Tue Jan 10 06:52:41 2012
+++ /branches/bleeding_edge/src/runtime.cc Tue Jan 10 08:06:32 2012
@@ -431,7 +431,6 @@
static const int kSmiOnlyLiteralMinimumLength = 1024;
-// static
Handle<Object> Runtime::CreateArrayLiteralBoilerplate(
Isolate* isolate,
Handle<FixedArray> literals,
=======================================
--- /branches/bleeding_edge/src/x64/lithium-x64.cc Thu Dec 22 08:23:47 2011
+++ /branches/bleeding_edge/src/x64/lithium-x64.cc Tue Jan 10 08:06:32 2012
@@ -1033,16 +1033,25 @@
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 @@
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::DoValueOf(HValueOf* instr) {
LOperand* object = UseRegister(instr->value());
LValueOf* result = new LValueOf(object);
- return AssignEnvironment(DefineSameAsFirst(result));
+ return DefineSameAsFirst(result);
}
@@ -1866,7 +1879,8 @@
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);
}
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