[v8] r8709 committed - Fix deopts caused by misplaced COW checks....

[codesite...@google.com]

Revision: 8709
Author: jkum...@chromium.org
Date: Thu Jul 21 05:01:51 2011
Log: Fix deopts caused by misplaced COW checks.

TEST=Performance of pixel-array-blur back to normal.

Review URL: http://codereview.chromium.org/7471034
http://code.google.com/p/v8/source/detail?r=8709

Modified:
/branches/bleeding_edge/src/hydrogen-instructions.h
/branches/bleeding_edge/src/hydrogen.cc

=======================================
--- /branches/bleeding_edge/src/hydrogen-instructions.h Wed Jul 20 07:43:10
2011
+++ /branches/bleeding_edge/src/hydrogen-instructions.h Thu Jul 21 05:01:51
2011
@@ -1898,10 +1898,14 @@
};

-class HCheckMap: public HUnaryOperation {
+class HCheckMap: public HTemplateInstruction<2> {
public:
- HCheckMap(HValue* value, Handle<Map> map)
- : HUnaryOperation(value), map_(map) {
+ HCheckMap(HValue* value, Handle<Map> map, HValue* typecheck = NULL)
+ : map_(map) {
+ SetOperandAt(0, value);
+ // If callers don't depend on a typecheck, they can pass in NULL. In
that
+ // case we use a copy of the |value| argument as a dummy value.
+ SetOperandAt(1, typecheck != NULL ? typecheck : value);
set_representation(Representation::Tagged());
SetFlag(kUseGVN);
SetFlag(kDependsOnMaps);
@@ -1913,6 +1917,7 @@
virtual void PrintDataTo(StringStream* stream);
virtual HType CalculateInferredType();

+ HValue* value() { return OperandAt(0); }
Handle<Map> map() const { return map_; }

DECLARE_CONCRETE_INSTRUCTION(CheckMap)
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Wed Jul 20 07:43:10 2011
+++ /branches/bleeding_edge/src/hydrogen.cc Thu Jul 21 05:01:51 2011
@@ -3911,7 +3911,7 @@
HInstruction* mapcheck = AddInstruction(new(zone()) HCheckMap(object,
map));
HInstruction* elements = AddInstruction(new(zone())
HLoadElements(object));
bool fast_double_elements = map->has_fast_double_elements();
- if (is_store && !fast_double_elements) {
+ if (is_store && map->has_fast_elements()) {
AddInstruction(new(zone()) HCheckMap(
elements, isolate()->factory()->fixed_array_map()));
}
@@ -4022,9 +4022,10 @@
elements_kind == JSObject::FAST_DOUBLE_ELEMENTS) {
bool fast_double_elements =
elements_kind == JSObject::FAST_DOUBLE_ELEMENTS;
- if (is_store && !fast_double_elements) {
+ if (is_store && elements_kind == JSObject::FAST_ELEMENTS) {
AddInstruction(new(zone()) HCheckMap(
- elements, isolate()->factory()->fixed_array_map()));
+ elements, isolate()->factory()->fixed_array_map(),
+ elements_kind_branch));
}
HBasicBlock* if_jsarray = graph()->CreateBasicBlock();
HBasicBlock* if_fastobject = graph()->CreateBasicBlock();