[webkit-reviews] review granted: [Bug 226984] Add a new pattern to instruction selector to utilize UBFX supported by ARM64 : [Attachment 431633] Patch

[bugzilla-daemon at webkit.org]

Filip Pizlo <fpizlo at apple.com> has granted Yijia Huang
<yijia_huang at apple.com>'s request for review:
Bug 226984: Add a new pattern to instruction selector to utilize UBFX supported
by ARM64
https://bugs.webkit.org/show_bug.cgi?id=226984

Attachment 431633: Patch

https://bugs.webkit.org/attachment.cgi?id=431633&action=review




--- Comment #8 from Filip Pizlo <fpizlo at apple.com> ---
Comment on attachment 431633
  --> https://bugs.webkit.org/attachment.cgi?id=431633
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=431633&action=review

It still looks good, but I would check that you're not missing an obvious
additional matching opportunity.

> Source/JavaScriptCore/b3/B3LowerToAir.cpp:2728
> +			   && lsb + width < (32 << (opcode == Ubfx64))

Is that right?

So, it's not possible to do, say, (src >> 16) & 0xFFFF?

It feels like this should be a <=, not a <.