Changeset 38369 in webkit for trunk/JavaScriptCore/VM/CodeBlock.h

Timestamp:

Nov 13, 2008, 4:53:35 AM (17 years ago)

Author:

[email protected]

Message:

2008-11-13 Maciej Stachowiak <​[email protected]>

Reviewed by Cameron Zwarich.

• remove immediate checks from native codegen for known non-immediate cases like "this"

~.5% speedup on v8 benchmarks

In the future we can extend this model to remove all sorts of
typechecks based on local type info or type inference.

I also added an assertion to verify that all slow cases linked as
many slow case jumps as the corresponding fast case generated, and
fixed the pre-existing cases where this was not true.

• VM/CTI.cpp: (JSC::CTI::emitJumpSlowCaseIfNotJSCell): (JSC::CTI::linkSlowCaseIfNotJSCell): (JSC::CTI::compileBinaryArithOp): (JSC::CTI::compileBinaryArithOpSlowCase): (JSC::CTI::privateCompileMainPass): (JSC::CTI::privateCompileSlowCases):
• VM/CTI.h:
• VM/CodeBlock.h: (JSC::CodeBlock::isKnownNotImmediate):

File:

• trunk/JavaScriptCore/VM/CodeBlock.h (modified) (1 diff)

trunk/JavaScriptCore/VM/CodeBlock.h

@@ -256 +256 @@
         }
 
+        inline bool isKnownNotImmediate(int index)
+        {
+            if (index == thisRegister)
+                return true;
+
+            if (isConstantRegisterIndex(index))
+                return !JSImmediate::isImmediate(getConstant(index));
+
+            return false;
+        }
+
         ALWAYS_INLINE bool isConstantRegisterIndex(int index)
         {