1874683 - Reimplement String.prototype.{codePointAt, at} in C++

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P1)

Description

[André Bargull [:anba]]

Re-implement String.prototype.{codePointAt, at} in C++ as an alternative to bug 1874373.

Comment 1

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 1: Clean-up and modernize String character access built-ins. r=jandem!

• Move jit::StringFromCharCode and jit::StringFromCodePoint to "builtin/String.cpp".
• Call js::StringFrom{CharCode,CodePoint} instead of str_from{CharCode,CodePoint}_one_arg
  to avoid unnecessary JS::Value boxing.
• Replace str_charCodeAt_impl by directly calling JSString::getChar in "jit/Recover.cpp",
  which allows to merge str_charCodeAt_impl and str_charCodeAt.
• Add ToStringIndex to use a single implementation for the character index computation, but
  mark it as MOZ_ALWAYS_INLINE to ensure we don't observe any calling overhead.
• Update spec references and step comments to match the latest spec draft.
• Add trailing comma after JS_FS_END for nicer clang-formatting.

Comment 2

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 2: Port String.prototype.codePointAt to C++. r=jandem!

Depends on D198557

Comment 3

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 3: Add MacroAssembler::add32 with three operands. r=jandem!

Used in part 5.

Depends on D198558

Comment 4

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 4: Add surrogate test methods to MacroAssembler. r=jandem!

Move the existing surrogate code point test code into MacroAssembler in
preparation for part 5.

Depends on D198559

Comment 5

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 5: Add MacroAssembler methods to load a code point. r=jandem!

Extend MacroAssembler::loadStringChar and the corresponding branch methods to
support loading code points from a string.

Depends on D198560

Comment 6

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 6: Inline String.prototype.codePointAt in CacheIR. r=jandem!

Depends on D198561

Comment 7

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 7: Transpile LoadStringCodePoint. r=jandem!

Transpile LoadStringCodePoint similar to how LoadStringCharCodeResult is processed.

Depends on D198562

Comment 8

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 8: Port String.prototype.at to C++. r=jandem!

Depends on D198563

Comment 9

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 9: Add MacroAssembler::cmp32Load32. r=jandem!

Used in part 10.

Depends on D198564

Comment 10

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 10: Inline String.prototype.at in CacheIR. r=jandem!

Depends on D198565

Comment 11

[André Bargull [:anba]]

Attachment: Bug 1874683 - Part 11: Transpile LoadStringAtResult. r=jandem!

Transpile LoadStringAtResult similar to how LoadStringCharResult is processed.

Depends on D198566

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8fd07a0373ed
Part 1: Clean-up and modernize String character access built-ins. r=jandem
https://hg.mozilla.org/integration/autoland/rev/167fa0e1edfc
Part 2: Port String.prototype.codePointAt to C++. r=jandem
https://hg.mozilla.org/integration/autoland/rev/041a4d1c5612
Part 3: Add MacroAssembler::add32 with three operands. r=jandem
https://hg.mozilla.org/integration/autoland/rev/3300300f9bcc
Part 4: Add surrogate test methods to MacroAssembler. r=jandem
https://hg.mozilla.org/integration/autoland/rev/018fe863b284
Part 5: Add MacroAssembler methods to load a code point. r=jandem
https://hg.mozilla.org/integration/autoland/rev/bfe3913d8912
Part 6: Inline String.prototype.codePointAt in CacheIR. r=jandem
https://hg.mozilla.org/integration/autoland/rev/e99e8882a3d7
Part 7: Transpile LoadStringCodePoint. r=jandem,nbp
https://hg.mozilla.org/integration/autoland/rev/6e500448d6a9
Part 8: Port String.prototype.at to C++. r=jandem
https://hg.mozilla.org/integration/autoland/rev/e267856d532c
Part 9: Add MacroAssembler::cmp32Load32. r=jandem
https://hg.mozilla.org/integration/autoland/rev/2098e0be66bf
Part 10: Inline String.prototype.at in CacheIR. r=jandem
https://hg.mozilla.org/integration/autoland/rev/3f41e0c8e5a1
Part 11: Transpile LoadStringAtResult. r=jandem

Comment 13

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/8fd07a0373ed
https://hg.mozilla.org/mozilla-central/rev/167fa0e1edfc
https://hg.mozilla.org/mozilla-central/rev/041a4d1c5612
https://hg.mozilla.org/mozilla-central/rev/3300300f9bcc
https://hg.mozilla.org/mozilla-central/rev/018fe863b284
https://hg.mozilla.org/mozilla-central/rev/bfe3913d8912
https://hg.mozilla.org/mozilla-central/rev/e99e8882a3d7
https://hg.mozilla.org/mozilla-central/rev/6e500448d6a9
https://hg.mozilla.org/mozilla-central/rev/e267856d532c
https://hg.mozilla.org/mozilla-central/rev/2098e0be66bf
https://hg.mozilla.org/mozilla-central/rev/3f41e0c8e5a1

Comment 14

[Mayank Bansal]

12% improvement on AWFY-Jetstream2-UniPoker-Average