commit 497f6b0cdd443c0d21373b4e2949e791073f3c13
author yusukesuzuki@slowstart.org <yusukesuzuki@slowstart.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Wed Oct 17 15:48:57 2018 +0000
committer yusukesuzuki@slowstart.org <yusukesuzuki@slowstart.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Wed Oct 17 15:48:57 2018 +0000
tree c68dbfbfc9c8b47b197529b98e1eb33e68a51a2f
parent 71d2888ed7b2b1de5431558219a271ffcc5e5e95

[JSC] More aggressively use `constexpr` in LowLevelInterpreter.asm for constant values
https://bugs.webkit.org/show_bug.cgi?id=190659

Reviewed by Keith Miller.

Asking the actual constant value to the JSC binary is always the best way to get the correct value.
The value is correctly updated once the original value is changed. We would like to encourage this
approach more in LowLevelInterpreter.asm.

This patch expands the coverage of this approach. We make ObservedType, ResultType, and ArithProfile
constexpr-friendly to produce the magic value used in LowLevelInterpreter.asm at compiling time.
This change allows us to easily extend ArithProfile in the future to adopt BigInt efficiently.

We additionally use `constexpr` for several constant values in LowLevelInterpreter.asm.

* assembler/MaxFrameExtentForSlowPathCall.h:
Use this value in LowLevelInterpreter.asm directly. We also make them constexpr. And we add CPU(ARM64E).

* bytecode/ArithProfile.h:
(JSC::ObservedType::ObservedType):
(JSC::ObservedType::sawInt32 const):
(JSC::ObservedType::isOnlyInt32 const):
(JSC::ObservedType::sawNumber const):
(JSC::ObservedType::isOnlyNumber const):
(JSC::ObservedType::sawNonNumber const):
(JSC::ObservedType::isOnlyNonNumber const):
(JSC::ObservedType::isEmpty const):
(JSC::ObservedType::bits const):
(JSC::ObservedType::withInt32 const):
(JSC::ObservedType::withNumber const):
(JSC::ObservedType::withNonNumber const):
(JSC::ObservedType::withoutNonNumber const):
(JSC::ObservedType::operator== const):
(JSC::ArithProfile::ArithProfile):
(JSC::ArithProfile::fromInt):
(JSC::ArithProfile::observedUnaryInt):
(JSC::ArithProfile::observedUnaryNumber):
(JSC::ArithProfile::observedBinaryIntInt):
(JSC::ArithProfile::observedBinaryNumberInt):
(JSC::ArithProfile::observedBinaryIntNumber):
(JSC::ArithProfile::observedBinaryNumberNumber):
(JSC::ArithProfile::lhsObservedType const):
(JSC::ArithProfile::rhsObservedType const):
(JSC::ArithProfile::bits const):
Make ObservedType and ArithProfile constexpr-friendly.

* llint/LLIntData.cpp:
(JSC::LLInt::Data::performAssertions):
Make several ASSERTs to STATIC_ASSERTs. Remove some unnecessary checks.
* llint/LLIntOffsetsExtractor.cpp:
* llint/LowLevelInterpreter.asm:
Remove unused constant values. Use constexpr more and more aggressively.

* parser/ResultType.h:
(JSC::ResultType::ResultType):
(JSC::ResultType::isInt32 const):
(JSC::ResultType::definitelyIsNumber const):
(JSC::ResultType::definitelyIsString const):
(JSC::ResultType::definitelyIsBoolean const):
(JSC::ResultType::definitelyIsBigInt const):
(JSC::ResultType::mightBeNumber const):
(JSC::ResultType::isNotNumber const):
(JSC::ResultType::mightBeBigInt const):
(JSC::ResultType::isNotBigInt const):
(JSC::ResultType::nullType):
(JSC::ResultType::booleanType):
(JSC::ResultType::numberType):
(JSC::ResultType::numberTypeIsInt32):
(JSC::ResultType::stringOrNumberType):
(JSC::ResultType::addResultType):
(JSC::ResultType::stringType):
(JSC::ResultType::bigIntType):
(JSC::ResultType::unknownType):
(JSC::ResultType::forAdd):
(JSC::ResultType::forLogicalOp):
(JSC::ResultType::forBitOp):
(JSC::ResultType::bits const):
Make ResultType constexpr-friendly.

* runtime/JSCJSValue.h:
Use offsetof instead of OBJECT_OFFSETOF. It is OK since EncodedValueDescriptor is POD.
This change makes TagOffset and PayloadOffset macros constexpr-friendly while OBJECT_OFFSETOF
cannot be used in constexpr since it uses reinterpret_cast.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@237220 268f45cc-cd09-0410-ab3c-d52691b4dbfc