864265 - Check for integer exponent in ecmaPow instead of js_math_pow

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jan de Mooij [:jandem]]

Attachment: Patch

Math.pow is often called with an exponent that's either int32 or double. js_math_pow already has a check for integer-valued doubles, but Ion code calls ecmaPow directly so we should just move the check there.

This is a noticeable win on Kraken imaging-darkroom and Octane-raytrace.

Comment 1

[Hannes Verschore [:h4writer]]

Comment on attachment 740216 [details] [diff] [review]
Patch

Review of attachment 740216 [details] [diff] [review]:
-----------------------------------------------------------------

Nice catch! Didn't see this one when investigating raytrace.

::: js/src/jsmath.cpp
@@ +498,5 @@
>  #endif
>  JSBool
>  js_math_pow(JSContext *cx, unsigned argc, Value *vp)
>  {
> +    double x, y;

I think you can leave the definition "z" here at the top.
(This is just to have at least 1 comment :P)

Comment 2

[Jan de Mooij [:jandem]]

Thanks for the quick review! Convention is to declare vars as close as possible to their first use, so I left the "double z" there.

https://hg.mozilla.org/integration/mozilla-inbound/rev/ebb2d369bad2

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/ebb2d369bad2