[webkit-dev] Proposal: Using LLInt Asm in major architectures even if JIT is disabled
guijemont at igalia.com
Wed Sep 19 03:12:02 PDT 2018
I did not run benchmarks with CLoop recently, but that has been my
observation on MIPS in the past as well, and I would therefore expect to
see similar results on Armv7, so I think it would make sense to do that
on these platforms too. Obviously, in all cases we would want to have a
cmake option to compile with CLoop, as that can be useful for
Quoting Yusuke Suzuki (2018-09-19 08:23:43)
> Hi WebKittens!
> Recently, node-jsc is announced. When I read the documents of that project,
> I found that they use LLInt ASM interpreter instead of CLoop in non-JIT
> So I had one question in my mind: How fast the LLInt ASM interpreter when
> comparing to CLoop?
> I've set up two builds. One is CLoop build (-DENABLE_JIT=OFF) and another is
> JIT build JSC with `JSC_useJIT=false`.
> And I've ran kraken benchmarks with these two builds in x64 Linux machine. The
> results are the followings.
> Benchmark report for Kraken on sakura-trick.
> VMs tested:
> "baseline" at /home/yusukesuzuki/dev/WebKit/WebKitBuild/nojit/Release/bin/jsc
> "patched" at /home/yusukesuzuki/dev/WebKit/WebKitBuild/nojit-llint/Release/bin/
> Collected 10 samples per benchmark/VM, with 10 VM invocations per benchmark.
> Emitted a call to gc() between sample
> measurements. Used 1 benchmark iteration per VM invocation for warm-up. Used
> the jsc-specific preciseTime()
> function to get microsecond-level timing. Reporting benchmark execution times
> with 95% confidence intervals in
> ai-astar 3619.974+-57.095 ^
> 2014.835+-59.016 ^ definitely 1.7967x faster
> audio-beat-detection 1762.085+-24.853 ^
> 1030.902+-19.743 ^ definitely 1.7093x faster
> audio-dft 1822.426+-28.704 ^
> 909.262+-16.640 ^ definitely 2.0043x faster
> audio-fft 1651.070+-9.994 ^
> 865.203+-7.912 ^ definitely 1.9083x faster
> audio-oscillator 1853.697+-26.539 ^
> 992.406+-12.811 ^ definitely 1.8679x faster
> imaging-darkroom 2118.737+-23.219 ^
> 1303.729+-8.071 ^ definitely 1.6251x faster
> imaging-desaturate 3133.654+-28.545 ^
> 1759.738+-18.182 ^ definitely 1.7808x faster
> imaging-gaussian-blur 16321.090+-154.893 ^
> 7228.017+-58.508 ^ definitely 2.2580x faster
> json-parse-financial 57.256+-2.876
> 56.101+-4.265 might be 1.0206x faster
> json-stringify-tinderbox 38.470+-2.788 ?
> 38.771+-0.935 ?
> stanford-crypto-aes 851.341+-7.738 ^
> 485.438+-13.904 ^ definitely 1.7538x faster
> stanford-crypto-ccm 556.133+-6.606 ^
> 264.161+-3.970 ^ definitely 2.1053x faster
> stanford-crypto-pbkdf2 1945.718+-15.968 ^
> 1075.013+-13.337 ^ definitely 1.8099x faster
> stanford-crypto-sha256-iterative 623.203+-7.604 ^
> 349.782+-12.810 ^ definitely 1.7817x faster
> <arithmetic> 2596.775+-14.857 ^
> 1312.383+-8.840 ^ definitely 1.9787x faster
> Surprisingly, LLInt ASM interpreter is significantly faster than CLoop. I
> expected it would be fast, but it would show around 10% performance win.
> But the reality is that it is 2x faster. It is too much number to me to
> consider enabling LLInt ASM interpreter for non-JIT build configuration.
> As a bonus, LLInt ASM interpreter offers sampling profiler support even in
> non-JIT environment.
> So my proposal is, how about enabling LLInt ASM interpreter in non-JIT
> configuration environment in major architectures (x64 and ARM64)?
> Best regards,
> Yusuke Suzuki
> : https://lists.webkit.org/pipermail/webkit-dev/2018-September/030140.html
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