https://bugs.webkit.org/show_bug.cgi?id=69717

Patch by Yuqiang Xian <yuqiang.xian@intel.com> on 2011-10-09
Reviewed by Filip Pizlo.

Current value profiling for 32_64 JIT is broken and cannot record
correct predicated types, which results in many speculation failures
in the 32_64 DFG JIT, fallbacks to baseline JIT, and re-optimizations
again and again.
With this fix 32_64 DFG JIT can demonstrate real performance gains.

* bytecode/ValueProfile.cpp:
(JSC::ValueProfile::computeStatistics):
* bytecode/ValueProfile.h:
(JSC::ValueProfile::classInfo):
(JSC::ValueProfile::numberOfSamples):
(JSC::ValueProfile::isLive):
(JSC::ValueProfile::numberOfInt32s):
(JSC::ValueProfile::numberOfDoubles):
(JSC::ValueProfile::numberOfBooleans):
(JSC::ValueProfile::dump):
    Empty value check should be performed on decoded JSValue,
    as for 32_64 empty value is not identical to encoded 0.
* jit/JIT.cpp:
(JSC::JIT::privateCompile):
* jit/JITInlineMethods.h:
(JSC::JIT::emitValueProfilingSite):
* jit/JITStubCall.h:
(JSC::JITStubCall::callWithValueProfiling):
    Record the right profiling result for 32_64.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@97025 268f45cc-cd09-0410-ab3c-d52691b4dbfc