[webkit-changes] [WebKit/WebKit] d77ef3: [JSC] Convert GetByVal + StringIdent constant to G...

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: d77ef3a80e9c9809eb75d531ede8be8b95712ae5
      https://github.com/WebKit/WebKit/commit/d77ef3a80e9c9809eb75d531ede8be8b95712ae5
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-04-20 (Thu, 20 Apr 2023)

  Changed paths:
    A JSTests/microbenchmarks/megamorphic-dfg.js
    M Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h
    M Source/JavaScriptCore/dfg/DFGConstantFoldingPhase.cpp
    M Source/JavaScriptCore/dfg/DFGNode.cpp
    M Source/JavaScriptCore/dfg/DFGNode.h

  Log Message:
  -----------
  [JSC] Convert GetByVal + StringIdent constant to GetById to encourage megamorphic IC
https://bugs.webkit.org/show_bug.cgi?id=255709
rdar://108302994

Reviewed by Alexey Shvayka.

This patch converts DFG/FTL GetByVal + StringIdent constant to GetById. The main benefit of this is that
we can use megamorphic IC from GetById.

                                ToT                     Patched

    megamorphic-dfg       10.9843+-0.0357     ^      7.3780+-0.0332        ^ definitely 1.4888x faster

* JSTests/microbenchmarks/megamorphic-dfg.js: Added.
(test):
(test2):
* Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
* Source/JavaScriptCore/dfg/DFGConstantFoldingPhase.cpp:
(JSC::DFG::ConstantFoldingPhase::foldConstants):
* Source/JavaScriptCore/dfg/DFGNode.cpp:
(JSC::DFG::Node::convertToGetById):
* Source/JavaScriptCore/dfg/DFGNode.h:

Canonical link: https://commits.webkit.org/263200@main