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oliver@apple.com authored
https://bugs.webkit.org/show_bug.cgi?id=116793 Source/JavaScriptCore: Reviewed by Mark Hahnenberg. This makes ArithDiv and ArithMod behave similarly, and moves both of their implementations entirely into DFGSpeculativeJIT.cpp into methods named like the ones for ArithSub/ArithMul. Specifically, ArithMod now uses the wrap-in-conversion-nodes idiom that ArithDiv used for platforms that don't support integer division. Previously ArithMod had its own int-to-double and double-to-int conversions for this purpose. As well, this gets rid of confusing methods like compileSoftModulo() (which did no such thing, there wasn't anything "soft" about it) and compileIntegerArithDivForX86() (which is accurately named but we don't use the platform-specific method convention anywhere else). Finally, this takes the optimized power-of-two modulo operation that was previously only for ARMv7s, and makes it available for all platforms. Well, sort of: I actually rewrote it to do what latest LLVM appears to do, which is a crazy straight-line power-of-2 modulo based on a combination of shifts, ands, additions, and subtractions. I can kind of understand it well enough to see that it complies with both C and JS power-of-2 modulo semantics. I've also confirmed that it does by testing (hence the corresponding improvements to one of the division tests). But, I don't claim to know exactly how this code works other than to observe that it is super leet. Overall, this patch has the effect of killing some code (no more hackish int-to-double conversions in ArithMod), making some optimization work on more platforms, and making the compiler less confusing by doing more things with the same idiom. * dfg/DFGAbstractState.cpp: (JSC::DFG::AbstractState::executeEffects): * dfg/DFGFixupPhase.cpp: (JSC::DFG::FixupPhase::fixupNode): * dfg/DFGSpeculativeJIT.cpp: (DFG): (JSC::DFG::SpeculativeJIT::compileArithDiv): (JSC::DFG::SpeculativeJIT::compileArithMod): * dfg/DFGSpeculativeJIT.h: (SpeculativeJIT): * dfg/DFGSpeculativeJIT32_64.cpp: (JSC::DFG::SpeculativeJIT::compile): * dfg/DFGSpeculativeJIT64.cpp: (JSC::DFG::SpeculativeJIT::compile): LayoutTests: Reviewed by Mark Hahnenberg. * fast/js/script-tests/integer-division-neg2tothe32-by-neg1.js: (myModBy2): (myModBy1073741824): git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153186 268f45cc-cd09-0410-ab3c-d52691b4dbfc
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