Changeset 149236 in webkit for trunk/Source/JavaScriptCore/runtime/JSCellInlines.h

Timestamp:

Apr 26, 2013, 11:43:33 PM (12 years ago)

Author:

[email protected]

Message:

Source/JavaScriptCore: Re-landing <​http://trac.webkit.org/changeset/148999>

Filled out more cases of branch folding in bytecode when emitting
expressions into a branching context
​https://bugs.webkit.org/show_bug.cgi?id=115057

Reviewed by Phil Pizlo.

We can't fold the number == 1 case to boolean because all non-zero numbers
down-cast to true, but only 1 is == to true.

Source/WTF: Filled out more cases of branch folding in bytecode when emitting expressions into a branching context
​https://bugs.webkit.org/show_bug.cgi?id=115057

Reviewed by Filip Pizlo.

Added a helper constructor for TriState so clients can make one without
branching or making assumptions about the integer values of TriStates.

• wtf/TriState.h:

(WTF::triState):
(WTF):

LayoutTests: Re-landing <​http://trac.webkit.org/changeset/148999>

Filled out more cases of branch folding in bytecode when emitting
expressions into a branching context
​https://bugs.webkit.org/show_bug.cgi?id=115057

Reviewed by Phil Pizlo.

Added a more exhaustive correctness test.

• fast/js/branch-fold-correctness-expected.txt: Added.
• fast/js/branch-fold-correctness.html: Added.

File:

• trunk/Source/JavaScriptCore/runtime/JSCellInlines.h (modified) (1 diff)

trunk/Source/JavaScriptCore/runtime/JSCellInlines.h

@@ -193 +193 @@
 }
 
+inline TriState JSCell::pureToBoolean() const
+{
+    if (isString()) 
+        return static_cast<const JSString*>(this)->toBoolean() ? TrueTriState : FalseTriState;
+    return MixedTriState;
+}
+
 } // namespace JSC