[webkit-changes] [WebKit/WebKit] 70f665: [JSC] Optimize 3~ parameter Math.min / Math.max

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 70f665155e30119d679eaca988e5e26ad70832d1
      https://github.com/WebKit/WebKit/commit/70f665155e30119d679eaca988e5e26ad70832d1
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2022-10-07 (Fri, 07 Oct 2022)

  Changed paths:
    A JSTests/stress/arith-min-max-multiple-constant-fold.js
    A JSTests/stress/arith-min-max-multiple.js
    M Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h
    M Source/JavaScriptCore/dfg/DFGArgumentsUtilities.cpp
    M Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp
    M Source/JavaScriptCore/dfg/DFGClobberize.h
    M Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
    M Source/JavaScriptCore/dfg/DFGGraph.h
    M Source/JavaScriptCore/dfg/DFGNodeType.h
    M Source/JavaScriptCore/dfg/DFGOperations.cpp
    M Source/JavaScriptCore/dfg/DFGOperations.h
    M Source/JavaScriptCore/dfg/DFGPredictionPropagationPhase.cpp
    M Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp
    M Source/JavaScriptCore/dfg/DFGValidate.cpp
    M Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp

  Log Message:
  -----------
  [JSC] Optimize 3~ parameter Math.min / Math.max
https://bugs.webkit.org/show_bug.cgi?id=246202
rdar://100884179

Reviewed by Mark Lam.

We found that JetStream2/chai-wtb is using Math.min(a, b, c) with three parameters,
and DFG / FTL gave up optimization for that right now. This patch changes ArithMin / ArithMax
to take variadic parameters so that we can emit code efficiently.

For Int32, we emit sequence of cmp and cmov, which should be compact and fast. For Double,
if the # of parameters are 3~, we call a runtime function which does max / min efficiently,
since double min/max are more complicated and this avoids bloating code.

This change offers 5-10% improvement in JetStream2/chai-wtb.

* Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
* Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::handleMinMax):
(JSC::DFG::ByteCodeParser::handleIntrinsicCall):
* Source/JavaScriptCore/dfg/DFGClobberize.h:
(JSC::DFG::clobberize):
* Source/JavaScriptCore/dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
* Source/JavaScriptCore/dfg/DFGGraph.h:
* Source/JavaScriptCore/dfg/DFGNodeType.h:
* Source/JavaScriptCore/dfg/DFGOperations.cpp:
(JSC::DFG::JSC_DEFINE_JIT_OPERATION):
* Source/JavaScriptCore/dfg/DFGOperations.h:
* Source/JavaScriptCore/dfg/DFGPredictionPropagationPhase.cpp:
* Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp:
* Source/JavaScriptCore/dfg/DFGValidate.cpp:
* Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp:
(JSC::FTL::DFG::LowerDFGToB3::compileArithMinOrMax):

Canonical link: https://commits.webkit.org/255288@main