Changeset 249880 in webkit for trunk/Source/JavaScriptCore/dfg/DFGArrayMode.cpp

Timestamp:

Sep 14, 2019, 12:36:29 PM (6 years ago)

Author:

[email protected]

Message:

Retire x86 32bit JIT support
​https://bugs.webkit.org/show_bug.cgi?id=201790

Reviewed by Mark Lam.

Source/JavaScriptCore:

Now, Xcode no longer has ability to build 32bit binary, so we cannot even test it on macOS.
Fedora stops shipping x86 32bit kernel. Our x86/x86_64 JIT requires SSE2, and so such relatively modern CPUs
can use JIT by switching x86 to x86_64. And these CPUs are modern enough to run CLoop at high speed.
WebKit already disabled x86 JIT by default while the implementation exists. So literary, it is not tested.

While x86 32bit becomes less useful, x86 32bit JIT backend is very complicated and is being a major maintenance burden.
This is due to very few # of registers. Which scatters a lot of isX86 / CPU(X86) in Baseline, DFG, and Yarr.

This patch retires x86 JIT support from JavaScriptCore and CSS JIT. We still keep MacroAssembler and GPRInfo / FPRInfo,
MachineContext information since they are useful even though JIT is not supported.

• dfg/DFGArrayMode.cpp:

(JSC::DFG::ArrayMode::refine const):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::handleIntrinsicCall):
(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):

• dfg/DFGJITCompiler.cpp:

(JSC::DFG::JITCompiler::compileExceptionHandlers):

• dfg/DFGOSRExitCompilerCommon.cpp:

(JSC::DFG::osrWriteBarrier):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileArithDiv):
(JSC::DFG::SpeculativeJIT::compileArithMod):
(JSC::DFG::SpeculativeJIT::compileCreateRest):
(JSC::DFG::SpeculativeJIT::compileGetDirectPname):

• dfg/DFGSpeculativeJIT.h:
• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::emitCall):
(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGThunks.cpp:

(JSC::DFG::osrExitGenerationThunkGenerator):

• ftl/FTLThunks.cpp:

(JSC::FTL::slowPathCallThunkGenerator):

• jit/AssemblyHelpers.cpp:

(JSC::AssemblyHelpers::callExceptionFuzz):
(JSC::AssemblyHelpers::debugCall):

• jit/AssemblyHelpers.h:

(JSC::AssemblyHelpers::emitComputeButterflyIndexingMask):

• jit/CCallHelpers.h:

(JSC::CCallHelpers::setupArgumentsImpl):
(JSC::CCallHelpers::prepareForTailCallSlow):

• jit/CallFrameShuffler.cpp:

(JSC::CallFrameShuffler::prepareForTailCall):

• jit/JIT.cpp:

(JSC::JIT::privateCompileExceptionHandlers):

• jit/JITArithmetic32_64.cpp:

(JSC::JIT::emit_op_mod):
(JSC::JIT::emitSlow_op_mod):

• jit/SlowPathCall.h:

(JSC::JITSlowPathCall::call):

• jit/ThunkGenerators.cpp:

(JSC::nativeForGenerator):
(JSC::arityFixupGenerator):

• wasm/WasmAirIRGenerator.cpp:

(JSC::Wasm::AirIRGenerator::emitModOrDiv):

• yarr/YarrJIT.cpp:

(JSC::Yarr::YarrGenerator::generateDotStarEnclosure):
(JSC::Yarr::YarrGenerator::generateEnter):
(JSC::Yarr::YarrGenerator::generateReturn):
(JSC::Yarr::YarrGenerator::compile):

• yarr/YarrJIT.h:

Source/WebCore:

• cssjit/FunctionCall.h:

(WebCore::FunctionCall::callAndBranchOnBooleanReturnValue):
(WebCore::FunctionCall::swapArguments):

Source/WTF:

• wtf/Platform.h:

File:

• trunk/Source/JavaScriptCore/dfg/DFGArrayMode.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/dfg/DFGArrayMode.cpp

@@ -304 +304 @@
                 return ArrayMode(Array::Generic, action());
             }
-            if (isX86() && is32Bit() && isScopedArgumentsSpeculation(base))
-                return ArrayMode(Array::Generic, action());
             return withType(type);
         }