Reviewers: fschneider,
Description:
Optimization: Do not assign an environment to LBranch when are sure that we
will
never deopt later.
Please review this at http://codereview.chromium.org/7524025/
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/ia32/lithium-ia32.cc
Index: src/ia32/lithium-ia32.cc
===================================================================
--- src/ia32/lithium-ia32.cc (revision 8758)
+++ src/ia32/lithium-ia32.cc (working copy)
@@ -1042,9 +1042,15 @@
return new LGoto(successor->block_id());
}
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 LBranch(UseRegister(v), temp));
+ LInstruction* branch = new LBranch(UseRegister(v), temp);
+ // When we handle all cases, we never deopt, so we don't need to assign
the
+ // environment then.
+ return expected.IsAll() ? branch : AssignEnvironment(branch);
}
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
