[webkit-changes] [WebKit/WebKit] 7202c5: [JSC] Use JumpTable in WasmBBQJIT

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 7202c59d1d29bec2ad6994e6c59aa4e27bf60f85
      https://github.com/WebKit/WebKit/commit/7202c59d1d29bec2ad6994e6c59aa4e27bf60f85
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-03-07 (Tue, 07 Mar 2023)

  Changed paths:
    M Source/JavaScriptCore/wasm/WasmBBQJIT.cpp
    M Source/JavaScriptCore/wasm/WasmBBQJIT.h
    M Source/JavaScriptCore/wasm/WasmBBQPlan.cpp
    M Source/JavaScriptCore/wasm/WasmBBQPlan.h
    M Source/JavaScriptCore/wasm/WasmCallee.h

  Log Message:
  -----------
  [JSC] Use JumpTable in WasmBBQJIT
https://bugs.webkit.org/show_bug.cgi?id=253472
rdar://106330476

Reviewed by Justin Michaud.

This patch implements JumpTable in WasmBBQJIT to implement wasm BrTable efficiently.
Currently, we are always doing binary-switch, which significantly bloats the code size.
Fortunately, wasm BrTable is super simple: targets are 0-N, and taking default if it exceeds N.
This is pretty easy to generate JumpTable for that.

We generate JumpTable in the link task, and put it in BBQCallee. It improves JetStream2/tsf-wasm's Runtime by 7~10%.

Before:
    Running tsf-wasm:
        Startup: 833.333
        Run time: 3.415
        Score: 53.349

After:
    Running tsf-wasm:
        Startup: 833.333
        Run time: 3.652
        Score: 55.169

* Source/JavaScriptCore/wasm/WasmBBQJIT.cpp:
(JSC::Wasm::BBQJIT::BBQJIT):
(JSC::Wasm::BBQJIT::addSwitch):
(JSC::Wasm::parseAndCompileBBQ):
* Source/JavaScriptCore/wasm/WasmBBQJIT.h:
* Source/JavaScriptCore/wasm/WasmBBQPlan.cpp:
(JSC::Wasm::BBQPlan::compileFunction):
* Source/JavaScriptCore/wasm/WasmBBQPlan.h:
* Source/JavaScriptCore/wasm/WasmCallee.h:

Canonical link: https://commits.webkit.org/261345@main