tree b7671a6f46ca603b266206fc4f3c61280a689126
parent 00eb52fc4d5e82cc9089a905ca2103f42783913d
author utatane.tea@gmail.com <utatane.tea@gmail.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1456799446 +0000
committer utatane.tea@gmail.com <utatane.tea@gmail.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1456799446 +0000

[DFG][FTL][B3] Support floor and ceil
https://bugs.webkit.org/show_bug.cgi?id=154683

Reviewed by Filip Pizlo.

Source/JavaScriptCore:

This patch implements and fixes the following things.

1. Implement Ceil and Floor in DFG, FTL and B3

x86 SSE 4.2 and ARM64 have round instructions that can directly perform Ceil or Floor.
This patch leverages this functionality. We introduce ArithFloor and ArithCeil.
During DFG phase, these nodes attempt to convert itself to Identity (in Fixup phase).
As the same to ArithRound, it tracks arith rounding mode.
And if these nodes are required to emit machine codes, we emit rounding machine code
if it is supported in the current machine. For example, in x86, we emit `round`.

This `Floor` functionality is nice for @toInteger in builtin.
That is used for Array.prototype.{forEach, map, every, some, reduce...}
And according to the benchmark results, Kraken audio-oscillator is slightly improved
due to its frequent Math.round and Math.floor calls.

2. Implement Floor in B3 and Air

As the same to Ceil in B3, we add a new B3 IR and Air opcode, Floor.
This Floor is leveraged to implement ArithFloor in DFG.

3. Fix ArithRound operation

Currently, we used cvtsd2si (in x86) to convert double value to int32.
And we also used this to implement Math.round, like, cvtsd2si(value + 0.5).
However, this implementation is not correct. Because cvtsd2si is not floor operation.
It is trucate operation. This is OK for positive numbers. But NG for negative numbers.
For example, the current implementation accidentally rounds `-0.6` to `-0.0`. This should be `-1.0`.
Using Ceil and Floor instructions, we implement correct ArithRound.

* assembler/MacroAssemblerARM.h:
(JSC::MacroAssemblerARM::supportsFloatingPointRounding):
(JSC::MacroAssemblerARM::ceilDouble):
(JSC::MacroAssemblerARM::floorDouble):
(JSC::MacroAssemblerARM::supportsFloatingPointCeil): Deleted.
* assembler/MacroAssemblerARM64.h:
(JSC::MacroAssemblerARM64::supportsFloatingPointRounding):
(JSC::MacroAssemblerARM64::floorFloat):
(JSC::MacroAssemblerARM64::supportsFloatingPointCeil): Deleted.
* assembler/MacroAssemblerARMv7.h:
(JSC::MacroAssemblerARMv7::supportsFloatingPointRounding):
(JSC::MacroAssemblerARMv7::ceilDouble):
(JSC::MacroAssemblerARMv7::floorDouble):
(JSC::MacroAssemblerARMv7::supportsFloatingPointCeil): Deleted.
* assembler/MacroAssemblerMIPS.h:
(JSC::MacroAssemblerMIPS::ceilDouble):
(JSC::MacroAssemblerMIPS::floorDouble):
(JSC::MacroAssemblerMIPS::supportsFloatingPointRounding):
(JSC::MacroAssemblerMIPS::supportsFloatingPointCeil): Deleted.
* assembler/MacroAssemblerSH4.h:
(JSC::MacroAssemblerSH4::supportsFloatingPointRounding):
(JSC::MacroAssemblerSH4::ceilDouble):
(JSC::MacroAssemblerSH4::floorDouble):
(JSC::MacroAssemblerSH4::supportsFloatingPointCeil): Deleted.
* assembler/MacroAssemblerX86Common.h:
(JSC::MacroAssemblerX86Common::floorDouble):
(JSC::MacroAssemblerX86Common::floorFloat):
(JSC::MacroAssemblerX86Common::supportsFloatingPointRounding):
(JSC::MacroAssemblerX86Common::supportsFloatingPointCeil): Deleted.
* b3/B3ConstDoubleValue.cpp:
(JSC::B3::ConstDoubleValue::floorConstant):
* b3/B3ConstDoubleValue.h:
* b3/B3ConstFloatValue.cpp:
(JSC::B3::ConstFloatValue::floorConstant):
* b3/B3ConstFloatValue.h:
* b3/B3LowerMacrosAfterOptimizations.cpp:
* b3/B3LowerToAir.cpp:
(JSC::B3::Air::LowerToAir::lower):
* b3/B3Opcode.cpp:
(WTF::printInternal):
* b3/B3Opcode.h:
* b3/B3ReduceDoubleToFloat.cpp:
* b3/B3ReduceStrength.cpp:
* b3/B3Validate.cpp:
* b3/B3Value.cpp:
(JSC::B3::Value::floorConstant):
(JSC::B3::Value::isRounded):
(JSC::B3::Value::effects):
(JSC::B3::Value::key):
(JSC::B3::Value::typeFor):
* b3/B3Value.h:
* b3/air/AirFixPartialRegisterStalls.cpp:
* b3/air/AirOpcode.opcodes:
* b3/testb3.cpp:
(JSC::B3::testFloorCeilArg):
(JSC::B3::testFloorArg):
(JSC::B3::testFloorImm):
(JSC::B3::testFloorMem):
(JSC::B3::testFloorFloorArg):
(JSC::B3::testCeilFloorArg):
(JSC::B3::testFloorIToD64):
(JSC::B3::testFloorIToD32):
(JSC::B3::testFloorArgWithUselessDoubleConversion):
(JSC::B3::testFloorArgWithEffectfulDoubleConversion):
(JSC::B3::run):
* dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
* dfg/DFGArithMode.cpp:
(WTF::printInternal):
* dfg/DFGArithMode.h:
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::handleIntrinsicCall):
* dfg/DFGClobberize.h:
(JSC::DFG::clobberize):
* dfg/DFGDoesGC.cpp:
(JSC::DFG::doesGC):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
* dfg/DFGGraph.cpp:
(JSC::DFG::Graph::dump):
* dfg/DFGGraph.h:
(JSC::DFG::Graph::roundShouldSpeculateInt32):
* dfg/DFGNode.h:
(JSC::DFG::Node::arithNodeFlags):
(JSC::DFG::Node::hasHeapPrediction):
(JSC::DFG::Node::hasArithRoundingMode):
* dfg/DFGNodeType.h:
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
* dfg/DFGSafeToExecute.h:
(JSC::DFG::safeToExecute):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compileArithRounding):
(JSC::DFG::SpeculativeJIT::compileArithRound): Deleted.
* dfg/DFGSpeculativeJIT.h:
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* ftl/FTLCapabilities.cpp:
(JSC::FTL::canCompile):
* ftl/FTLLowerDFGToB3.cpp:
(JSC::FTL::DFG::LowerDFGToB3::compileNode):
(JSC::FTL::DFG::LowerDFGToB3::compileArithRound):
(JSC::FTL::DFG::LowerDFGToB3::compileArithFloor):
(JSC::FTL::DFG::LowerDFGToB3::compileArithCeil):
* ftl/FTLOutput.h:
(JSC::FTL::Output::doubleFloor):
* jit/ThunkGenerators.cpp:
(JSC::ceilThunkGenerator):
* tests/stress/math-ceil-arith-rounding-mode.js: Added.
(firstCareAboutZeroSecondDoesNot):
(firstDoNotCareAboutZeroSecondDoes):
(warmup):
(verifyNegativeZeroIsPreserved):
* tests/stress/math-ceil-basics.js: Added.
(mathCeilOnIntegers):
(mathCeilOnDoubles):
(mathCeilOnBooleans):
(uselessMathCeil):
(mathCeilWithOverflow):
(mathCeilConsumedAsDouble):
(mathCeilDoesNotCareAboutMinusZero):
(mathCeilNoArguments):
(mathCeilTooManyArguments):
(testMathCeilOnConstants):
(mathCeilStructTransition):
(Math.ceil):
* tests/stress/math-floor-arith-rounding-mode.js: Added.
(firstCareAboutZeroSecondDoesNot):
(firstDoNotCareAboutZeroSecondDoes):
(warmup):
(verifyNegativeZeroIsPreserved):
* tests/stress/math-floor-basics.js: Added.
(mathFloorOnIntegers):
(mathFloorOnDoubles):
(mathFloorOnBooleans):
(uselessMathFloor):
(mathFloorWithOverflow):
(mathFloorConsumedAsDouble):
(mathFloorDoesNotCareAboutMinusZero):
(mathFloorNoArguments):
(mathFloorTooManyArguments):
(testMathFloorOnConstants):
(mathFloorStructTransition):
(Math.floor):
* tests/stress/math-round-should-not-use-truncate.js: Added.
(mathRoundDoesNotCareAboutMinusZero):
* tests/stress/math-rounding-infinity.js: Added.
(shouldBe):
(testRound):
(testFloor):
(testCeil):
* tests/stress/math-rounding-nan.js: Added.
(shouldBe):
(testRound):
(testFloor):
(testCeil):
* tests/stress/math-rounding-negative-zero.js: Added.
(shouldBe):
(testRound):
(testFloor):
(testCeil):
(testRoundNonNegativeZero):
(testRoundNonNegativeZero2):

Websites/webkit.org:

* docs/b3/intermediate-representation.html:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@197380 268f45cc-cd09-0410-ab3c-d52691b4dbfc