297604 - don't use regparm on Mac OS X

Status: RESOLVED FIXED

(Core :: General, defect)

Description

[Josh Aas]

We can't use regparm now that Mac OS X can be on ppc or x86.  Exclude Mac OS X from using regparm. 
Patch by Apple Computer, Inc. <- no guarantees from them, however

Comment 1

[Josh Aas]

Attachment: patch v1.0

Comment 2

[Brian Ryner (not reading)]

Comment on attachment 186165 [details] [diff] [review]
patch v1.0

Maybe it would be better to move this logic to configure, and have it define
HAVE_REGPARM_ATTRIBUTE?

Comment 3

[Josh Aas]

Ronnie - can you give your explanation for this patch on the bug? You said it best at WWDC.

Comment 4

[Ronnie Misra]

Currently, Mac OS X on Intel doesn't properly handle regparm calls between different libraries -- the dyld 
stub tramples registers eax and edx. We'll hopefully fix this in a later release, but until then, regparm calls 
will get garbage parameters.

The problem is not that regparm is not defined, but rather that it behaves poorly. My hope is that this is 
just a temporary work-around, so I personally wouldn't invest the time in detecting this at autoconf time.

Comment 5

[Josh Aas]

Ronnie - what releases of Mac OS X in particular have regparm issues? Just the
x86 developer release? If that is the case, then we should land the #ifdef fix
with a comment explaining the situation.

Comment 6

[Ronnie Misra]

I do consider this to be a bug and will be pushing to get this bug fixed. That being said, I don't know when 
it will be fixed.

Comment 7

[Josh Aas]

Ronnie - but what versions of Mac OS X is this a bug in?

Comment 8

[Ronnie Misra]

Josh - Well, there's only one version of OS X on Intel currently, the release that came with the transition 
kits. :)

Comment 9

[Josh Aas]

I just wanted to make sure there was no badness in any ppc versions of Mac OS X.

Comment 10

[Ronnie Misra]

Josh - gcc doesn't support a regparm directive on ppc. This fix is in x86-specific code.

Comment 11

[Josh Aas]

I missed reading the #ifdef (__i386__)... I was just looking at the file names
for arch specificity. My bad.

Comment 12

[Simon Fraser [no longer active]]

Comment on attachment 186165 [details] [diff] [review]
patch v1.0

What about these other uses of __i386__ ?
http://lxr.mozilla.org/mozilla/search?string=__i386__

Comment 13

[Josh Aas]

In most cases we can be considered i386, but it so happens that regparm is
broken on mactel right now so we need to special case it.

Comment 14

[Benjamin Smedberg]

Comment on attachment 186165 [details] [diff] [review]
patch v1.0

bah

Comment 15

[Josh Aas]

landed on trunk

Comment 16

[Ronnie Misra]

regparm can be turned back on for the OS X Intel builds -- we support regparm properly in 10.4.4 on Intel.

Comment 17

[Mark Mentovai]

Bug 323337 turned it back on.