Changeset 157209 in webkit for trunk/Source/JavaScriptCore/ftl/FTLCArgumentGetter.cpp

Timestamp:

Oct 9, 2013, 9:24:57 PM (12 years ago)

Author:

[email protected]

Message:

FTL should be able to do simple OSR exits using llvm.webkit.stackmap
​https://bugs.webkit.org/show_bug.cgi?id=122538

Reviewed by Oliver Hunt.

This gives the FTL the ability to OSR exit using the llvm.webkit.stackmap intrinsic.

• The FTL compiles all OSR exit calls as calls to llvm.webkit.stackmap with a unique ID, passing a requested size that is big enough for own jump replacement.

• After LLVM compilation, we parse the new LLVM stackmap section.

• For all llvm.webkit.stackmaps that we used for OSR exits, we do a jumpReplacement, which targets exit thunks that we generate.

• If an exit thunk fires, it causes JSC to compile an exit off-ramp that uses a combination of the JSC-internal OSR exit accounting (FTL::ExitValue and friends) and LLVM stackmap's accounting of where data actually ended up (register, indirect, constant) to reconstruct bytecode state.

This still has shortcomings; for example it cannot handle XMM or YMM registers. Handling
YMM registers will require adding some basic YMM support to our assemblers - really we
just need the ability to move a YMM's value into a GPR.

This patch preserves all of the old, intrinsic-less, FTL OSR exit support. Hence it
manages to pass all existing FTL tests even despite its incompleteness. I think that's
the right way to go since this is already a big patch, and anyway it would be great to
keep the intrinsic-less FTL OSR exit support so long as the LLVM side of this hasn't
landed.

• JavaScriptCore.xcodeproj/project.pbxproj:
• assembler/AbstractMacroAssembler.h:

(JSC::AbstractMacroAssembler::firstRegister):
(JSC::AbstractMacroAssembler::lastRegister):

• assembler/MacroAssembler.h:

(JSC::MacroAssembler::isStackRelated):
(JSC::MacroAssembler::firstRealRegister):
(JSC::MacroAssembler::nextRegister):
(JSC::MacroAssembler::secondRealRegister):

• assembler/MacroAssemblerX86Common.h:
• assembler/X86Assembler.h:

(JSC::X86Assembler::firstRegister):
(JSC::X86Assembler::lastRegister):

• dfg/DFGPlan.cpp:

(JSC::DFG::Plan::compileInThreadImpl):

• ftl/FTLCArgumentGetter.cpp:

(JSC::FTL::CArgumentGetter::loadNextAndBox):

• ftl/FTLCArgumentGetter.h:

(JSC::FTL::CArgumentGetter::loadNextDoubleIntoGPR):

• ftl/FTLCompile.cpp:

(JSC::FTL::mmAllocateCodeSection):
(JSC::FTL::mmAllocateDataSection):
(JSC::FTL::dumpDataSection):
(JSC::FTL::fixFunctionBasedOnStackMaps):
(JSC::FTL::compile):

• ftl/FTLExitThunkGenerator.cpp:

(JSC::FTL::ExitThunkGenerator::emitThunk):
(JSC::FTL::ExitThunkGenerator::emitThunks):

• ftl/FTLExitThunkGenerator.h:
• ftl/FTLExitValue.h:

(JSC::FTL::ExitValue::isInJSStackSomehow):
(JSC::FTL::ExitValue::valueFormat):

• ftl/FTLFail.cpp:

(JSC::FTL::fail):

• ftl/FTLIntrinsicRepository.h:
• ftl/FTLJITCode.h:
• ftl/FTLLowerDFGToLLVM.cpp:

(JSC::FTL::generateExitThunks):
(JSC::FTL::LowerDFGToLLVM::LowerDFGToLLVM):
(JSC::FTL::LowerDFGToLLVM::appendOSRExit):
(JSC::FTL::LowerDFGToLLVM::emitOSRExitCall):
(JSC::FTL::LowerDFGToLLVM::linkOSRExitsAndCompleteInitializationBlocks):

• ftl/FTLOSRExit.h:
• ftl/FTLOSRExitCompilationInfo.h:

(JSC::FTL::OSRExitCompilationInfo::OSRExitCompilationInfo):

• ftl/FTLOSRExitCompiler.cpp:

(JSC::FTL::compileStubWithOSRExitStackmap):
(JSC::FTL::compileStubWithoutOSRExitStackmap):
(JSC::FTL::compileFTLOSRExit):

• ftl/FTLSaveRestore.cpp: Added.

(JSC::FTL::bytesForGPRs):
(JSC::FTL::requiredScratchMemorySizeInBytes):
(JSC::FTL::offsetOfGPR):
(JSC::FTL::saveAllRegisters):
(JSC::FTL::restoreAllRegisters):

• ftl/FTLSaveRestore.h: Added.
• ftl/FTLStackMaps.cpp: Added.

(JSC::FTL::readObject):
(JSC::FTL::StackMaps::Constant::parse):
(JSC::FTL::StackMaps::Constant::dump):
(JSC::FTL::StackMaps::Location::parse):
(JSC::FTL::StackMaps::Location::dump):
(JSC::FTL::StackMaps::Location::involvesGPR):
(JSC::FTL::StackMaps::Location::isGPR):
(JSC::FTL::StackMaps::Location::gpr):
(JSC::FTL::StackMaps::Location::restoreInto):
(JSC::FTL::StackMaps::Record::parse):
(JSC::FTL::StackMaps::Record::dump):
(JSC::FTL::StackMaps::parse):
(JSC::FTL::StackMaps::dump):
(JSC::FTL::StackMaps::dumpMultiline):
(JSC::FTL::StackMaps::getRecordMap):
(WTF::printInternal):

• ftl/FTLStackMaps.h: Added.
• ftl/FTLState.h:
• ftl/FTLThunks.cpp:

(JSC::FTL::osrExitGenerationThunkGenerator):

• ftl/FTLValueFormat.cpp:

(JSC::FTL::reboxAccordingToFormat):

• ftl/FTLValueFormat.h:
• runtime/DataView.cpp:

(JSC::DataView::create):

• runtime/DataView.h:

(JSC::DataView::read):

• runtime/Options.h:

File:

• trunk/Source/JavaScriptCore/ftl/FTLCArgumentGetter.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/ftl/FTLCArgumentGetter.cpp

@@ -53 +53 @@
     
     switch (format) {
-    case ValueFormatInt32: {
+    case ValueFormatInt32:
+    case ValueFormatUInt32:
         loadNext32(destination);
-        m_jit.or64(GPRInfo::tagTypeNumberRegister, destination);
         break;
-    }
-            
-    case ValueFormatUInt32: {
-        loadNext32(destination);
-        m_jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
-        m_jit.boxInt52(destination, destination, scratch1, FPRInfo::fpRegT0);
-        m_jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
-        break;
-    }
         
-    case ValueFormatInt52: {
-        loadNext64(destination);
-        m_jit.rshift64(AssemblyHelpers::TrustedImm32(JSValue::int52ShiftAmount), destination);
-        m_jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
-        m_jit.boxInt52(destination, destination, scratch1, FPRInfo::fpRegT0);
-        m_jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
-        break;
-    }
-            
-    case ValueFormatStrictInt52: {
-        loadNext64(destination);
-        m_jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch2);
-        m_jit.boxInt52(destination, destination, scratch1, FPRInfo::fpRegT0);
-        m_jit.move64ToDouble(scratch2, FPRInfo::fpRegT0);
-        break;
-    }
-            
-    case ValueFormatBoolean: {
-        loadNext8(destination);
-        m_jit.or32(MacroAssembler::TrustedImm32(ValueFalse), destination);
-        break;
-    }
-            
-    case ValueFormatJSValue: {
+    case ValueFormatInt52:
+    case ValueFormatStrictInt52:
+    case ValueFormatJSValue:
         loadNext64(destination);
         break;
-    }
             
-    case ValueFormatDouble: {
-        m_jit.moveDoubleTo64(FPRInfo::fpRegT0, scratch1);
-        loadNextDouble(FPRInfo::fpRegT0);
-        m_jit.boxDouble(FPRInfo::fpRegT0, destination);
-        m_jit.move64ToDouble(scratch1, FPRInfo::fpRegT0);
+    case ValueFormatBoolean:
+        loadNext8(destination);
         break;
-    }
+            
+    case ValueFormatDouble:
+        loadNextDoubleIntoGPR(destination);
+        break;
             
     default:
@@ -107 +76 @@
         break;
     }
+    
+    reboxAccordingToFormat(format, m_jit, destination, scratch1, scratch2);
 }