[webkit-changes] [WebKit/WebKit] 57a776: [JSC] String and Number multiplication should be o...

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 57a7762336eea989764e026e58f1e3a5e845f652
      https://github.com/WebKit/WebKit/commit/57a7762336eea989764e026e58f1e3a5e845f652
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2024-01-14 (Sun, 14 Jan 2024)

  Changed paths:
    A JSTests/microbenchmarks/string-number-mul-int32.js
    A JSTests/microbenchmarks/string-number-mul.js
    M Source/JavaScriptCore/dfg/DFGFixupPhase.cpp

  Log Message:
  -----------
  [JSC] String and Number multiplication should be optimized
https://bugs.webkit.org/show_bug.cgi?id=267507
rdar://120930167

Reviewed by Justin Michaud.

We observed that `string * number` pattern in the wild. This patch optimizes it in DFG / FTL layer
by converting ValueMul(String, Number) to ArithMul(ToNumber(String), Number).

                                        ToT                     Patched

    string-number-mul-int32       15.3303+-0.0371     ^     12.2364+-0.0633        ^ definitely 1.2528x faster
    string-number-mul             16.4883+-0.0731     ^     13.9290+-0.0953        ^ definitely 1.1837x faster

* JSTests/microbenchmarks/string-number-mul.js: Added.
(test):
* Source/JavaScriptCore/dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):

Canonical link: https://commits.webkit.org/273024@main