Reviewers: fschneider,
Description:
Prohibit moving instructions with side effects via 'EmitAtUses'.
It's not generally safe to decide to delay the evaluation of an expression
with side effects until it is used.
BUG=v8:1138
Please review this at http://codereview.chromium.org/6474035/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge/build/ia32
Affected files:
M src/hydrogen-instructions.h
Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index
d6d5cfb891f1dbffc7f85d7c82ef87b33f804811..701813133c4795807d4d070fe915fc0a074ece9b
100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -2208,7 +2208,11 @@ class HCompare: public HBinaryOperation {
}
void SetInputRepresentation(Representation r);
- virtual bool EmitAtUses() const { return uses()->length() <= 1; }
+
+ virtual bool EmitAtUses() const {
+ return !HasSideEffects() && (uses()->length() <= 1);
+ }
+
virtual Representation RequiredInputRepresentation(int index) const {
return input_representation_;
}
@@ -2246,7 +2250,10 @@ class HCompareJSObjectEq: public HBinaryOperation {
SetFlag(kUseGVN);
}
- virtual bool EmitAtUses() const { return uses()->length() <= 1; }
+ virtual bool EmitAtUses() const {
+ return !HasSideEffects() && (uses()->length() <= 1);
+ }
+
virtual Representation RequiredInputRepresentation(int index) const {
return Representation::Tagged();
}
@@ -2265,7 +2272,11 @@ class HUnaryPredicate: public HUnaryOperation {
set_representation(Representation::Tagged());
SetFlag(kUseGVN);
}
- virtual bool EmitAtUses() const { return uses()->length() <= 1; }
+
+ virtual bool EmitAtUses() const {
+ return !HasSideEffects() && (uses()->length() <= 1);
+ }
+
virtual Representation RequiredInputRepresentation(int index) const {
return Representation::Tagged();
}
@@ -2322,7 +2333,9 @@ class HIsConstructCall: public HInstruction {
SetFlag(kUseGVN);
}
- virtual bool EmitAtUses() const { return uses()->length() <= 1; }
+ virtual bool EmitAtUses() const {
+ return !HasSideEffects() && (uses()->length() <= 1);
+ }
DECLARE_CONCRETE_INSTRUCTION(IsConstructCall, "is_construct_call")
@@ -2427,7 +2440,9 @@ class HInstanceOf: public HInstruction {
HValue* left() const { return operands_[1]; }
HValue* right() const { return operands_[2]; }
- virtual bool EmitAtUses() const { return uses()->length() <= 1; }
+ virtual bool EmitAtUses() const {
+ return !HasSideEffects() && (uses()->length() <= 1);
+ }
virtual Representation RequiredInputRepresentation(int index) const {
return Representation::Tagged();
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
