[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
diff --git a/Source/JavaScriptCore/assembler/MaxFrameExtentForSlowPathCall.h b/Source/JavaScriptCore/assembler/MaxFrameExtentForSlowPathCall.h
index 4321305..6dac09c 100644
--- a/Source/JavaScriptCore/assembler/MaxFrameExtentForSlowPathCall.h
+++ b/Source/JavaScriptCore/assembler/MaxFrameExtentForSlowPathCall.h
@@ -36,44 +36,44 @@
// from JS code.
#if !ENABLE(ASSEMBLER)
-static const size_t maxFrameExtentForSlowPathCall = 0;
+static constexpr size_t maxFrameExtentForSlowPathCall = 0;
#elif CPU(X86_64) && OS(WINDOWS)
// 4 args in registers, but stack space needs to be allocated for all args.
-static const size_t maxFrameExtentForSlowPathCall = 64;
+static constexpr size_t maxFrameExtentForSlowPathCall = 64;
#elif CPU(X86_64)
// All args in registers.
-static const size_t maxFrameExtentForSlowPathCall = 0;
+static constexpr size_t maxFrameExtentForSlowPathCall = 0;
#elif CPU(X86)
// 7 args on stack (28 bytes).
-static const size_t maxFrameExtentForSlowPathCall = 40;
+static constexpr size_t maxFrameExtentForSlowPathCall = 40;
-#elif CPU(ARM64)
+#elif CPU(ARM64) || CPU(ARM64E)
// All args in registers.
-static const size_t maxFrameExtentForSlowPathCall = 0;
+static constexpr size_t maxFrameExtentForSlowPathCall = 0;
#elif CPU(ARM)
// First four args in registers, remaining 4 args on stack.
-static const size_t maxFrameExtentForSlowPathCall = 24;
+static constexpr size_t maxFrameExtentForSlowPathCall = 24;
#elif CPU(MIPS)
// Though args are in registers, there need to be space on the stack for all args.
-static const size_t maxFrameExtentForSlowPathCall = 40;
+static constexpr size_t maxFrameExtentForSlowPathCall = 40;
#else
#error "Unsupported CPU: need value for maxFrameExtentForSlowPathCall"
#endif
-COMPILE_ASSERT(!(maxFrameExtentForSlowPathCall % sizeof(Register)), extent_must_be_in_multiples_of_registers);
+static_assert(!(maxFrameExtentForSlowPathCall % sizeof(Register)), "Extent must be in multiples of registers");
#if ENABLE(ASSEMBLER)
// Make sure that cfr - maxFrameExtentForSlowPathCall bytes will make the stack pointer aligned
-COMPILE_ASSERT((maxFrameExtentForSlowPathCall % 16) == 16 - sizeof(CallerFrameAndPC), extent_must_align_stack_from_callframe_pointer);
+static_assert((maxFrameExtentForSlowPathCall % 16) == 16 - sizeof(CallerFrameAndPC), "Extent must align stack from callframe pointer");
#endif
-static const size_t maxFrameExtentForSlowPathCallInRegisters = maxFrameExtentForSlowPathCall / sizeof(Register);
+static constexpr size_t maxFrameExtentForSlowPathCallInRegisters = maxFrameExtentForSlowPathCall / sizeof(Register);
} // namespace JSC
