Reveal array bounds checks in DFG IR
https://bugs.webkit.org/show_bug.cgi?id=125253

Reviewed by Oliver Hunt and Mark Hahnenberg.
        
In SSA mode, this reveals array bounds checks and the load of array length in DFG IR,
making this a candidate for LICM.

This also fixes a long-standing performance bug where the JSObject slow paths would
always create contiguous storage, rather than type-specialized storage, when doing a
"storage creating" storage, like:
        
    var o = {};
    o[0] = 42;

* CMakeLists.txt:
* GNUmakefile.list.am:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
* JavaScriptCore.xcodeproj/project.pbxproj:
* bytecode/ExitKind.cpp:
(JSC::exitKindToString):
(JSC::exitKindIsCountable):
* bytecode/ExitKind.h:
* dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::::executeEffects):
* dfg/DFGArrayMode.cpp:
(JSC::DFG::permitsBoundsCheckLowering):
(JSC::DFG::ArrayMode::permitsBoundsCheckLowering):
* dfg/DFGArrayMode.h:
(JSC::DFG::ArrayMode::lengthNeedsStorage):
* dfg/DFGClobberize.h:
(JSC::DFG::clobberize):
* dfg/DFGConstantFoldingPhase.cpp:
(JSC::DFG::ConstantFoldingPhase::foldConstants):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
* dfg/DFGNodeType.h:
* dfg/DFGPlan.cpp:
(JSC::DFG::Plan::compileInThreadImpl):
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
* dfg/DFGSSALoweringPhase.cpp: Added.
(JSC::DFG::SSALoweringPhase::SSALoweringPhase):
(JSC::DFG::SSALoweringPhase::run):
(JSC::DFG::SSALoweringPhase::handleNode):
(JSC::DFG::SSALoweringPhase::lowerBoundsCheck):
(JSC::DFG::performSSALowering):
* dfg/DFGSSALoweringPhase.h: Added.
* dfg/DFGSafeToExecute.h:
(JSC::DFG::safeToExecute):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compileDoublePutByVal):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compileContiguousPutByVal):
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* ftl/FTLCapabilities.cpp:
(JSC::FTL::canCompile):
* ftl/FTLLowerDFGToLLVM.cpp:
(JSC::FTL::LowerDFGToLLVM::compileNode):
(JSC::FTL::LowerDFGToLLVM::compileCheckInBounds):
(JSC::FTL::LowerDFGToLLVM::compileGetByVal):
(JSC::FTL::LowerDFGToLLVM::compilePutByVal):
(JSC::FTL::LowerDFGToLLVM::contiguousPutByValOutOfBounds):
* runtime/JSObject.cpp:
(JSC::JSObject::convertUndecidedForValue):
(JSC::JSObject::createInitialForValueAndSet):
(JSC::JSObject::putByIndexBeyondVectorLength):
(JSC::JSObject::putDirectIndexBeyondVectorLength):
* runtime/JSObject.h:
* tests/stress/float32array-out-of-bounds.js: Added.
(make):
(foo):
(test):
* tests/stress/int32-object-out-of-bounds.js: Added.
(make):
(foo):
(test):
* tests/stress/int32-out-of-bounds.js: Added.
(foo):
(test):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@160347 268f45cc-cd09-0410-ab3c-d52691b4dbfc