[webkit-reviews] review requested: [Bug 126985] Source/WTF/wtf/Atomics.h:300: Error: bad register name `%bpl' : [Attachment 221366] Patch

[bugzilla-daemon at webkit.org]

Alberto Garcia <berto at igalia.com> has asked  for review:
Bug 126985: Source/WTF/wtf/Atomics.h:300: Error: bad register name `%bpl'
https://bugs.webkit.org/show_bug.cgi?id=126985

Attachment 221366: Patch
https://bugs.webkit.org/attachment.cgi?id=221366&action=review

------- Additional Comments from Alberto Garcia <berto at igalia.com>
The problem is that with the "r" constraint we are telling gcc to put
'newValue' into any general register, which is then used as an operand
for cmpxchgb.

However in i386 not all registers allow access to their lower byte,
which is what we need here.

The "q" constraint ensures that in 32-bit mode only the a, b, c and d
registers are used.