Revision: 17912
Author: [email protected]
Date: Wed Nov 20 11:53:09 2013 UTC
Log: Don't generate useless string checks for string adds.
If we know that one side of a string add is definitely a string
(i.e. if it's a string constant), then we don't need to emit a
string check for the argument.
This adds a new BuildCheckString() method to the graph builder,
which does "the right thing".
TEST=mjsunit/string-add
[email protected]
Review URL: https://codereview.chromium.org/78063002
http://code.google.com/p/v8/source/detail?r=17912
Modified:
/branches/bleeding_edge/src/hydrogen.cc
/branches/bleeding_edge/src/hydrogen.h
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Tue Nov 19 16:41:07 2013 UTC
+++ /branches/bleeding_edge/src/hydrogen.cc Wed Nov 20 11:53:09 2013 UTC
@@ -1271,6 +1271,20 @@
HValue* HGraphBuilder::BuildCheckMap(HValue* obj, Handle<Map> map) {
return Add<HCheckMaps>(obj, map, top_info());
}
+
+
+HValue* HGraphBuilder::BuildCheckString(
+ HValue* object, const char* failure_reason) {
+ if (!object->type().IsString()) {
+ ASSERT(!object->IsConstant() ||
+ !HConstant::cast(object)->HasStringValue());
+ IfBuilder if_isstring(this);
+ if_isstring.If<HIsStringAndBranch>(object);
+ if_isstring.Then();
+ if_isstring.ElseDeopt(failure_reason);
+ }
+ return object;
+}
HValue* HGraphBuilder::BuildWrapReceiver(HValue* object, HValue* function)
{
@@ -8631,18 +8645,14 @@
(left_type->Is(Type::String()) || right_type->Is(Type::String()))) {
// Validate type feedback for left argument.
if (left_type->Is(Type::String())) {
- IfBuilder if_isstring(this);
- if_isstring.If<HIsStringAndBranch>(left);
- if_isstring.Then();
- if_isstring.ElseDeopt("Expected string for LHS of binary operation");
+ left = BuildCheckString(
+ left, "Expected string for LHS of binary operation");
}
// Validate type feedback for right argument.
if (right_type->Is(Type::String())) {
- IfBuilder if_isstring(this);
- if_isstring.If<HIsStringAndBranch>(right);
- if_isstring.Then();
- if_isstring.ElseDeopt("Expected string for RHS of binary operation");
+ right = BuildCheckString(
+ right, "Expected string for RHS of binary operation");
}
// Convert left argument as necessary.
=======================================
--- /branches/bleeding_edge/src/hydrogen.h Mon Nov 18 13:57:49 2013 UTC
+++ /branches/bleeding_edge/src/hydrogen.h Wed Nov 20 11:53:09 2013 UTC
@@ -1256,6 +1256,7 @@
HValue* BuildCheckHeapObject(HValue* object);
HValue* BuildCheckMap(HValue* obj, Handle<Map> map);
+ HValue* BuildCheckString(HValue* object, const char* failure_reason);
HValue* BuildWrapReceiver(HValue* object, HValue* function);
// Building common constructs
--
--
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