LLVM miscompiles more functions from Wine

[llvmbot]

Bugzilla Link	9694
Resolution	INVALID
Resolved on	Apr 13, 2011 12:37
Version	trunk
OS	Linux
Reporter	LLVM Bugzilla Contributor
CC	@echristo

Extended Description

Austin English on freenode#winehackers reported yet another LLVM miscompilation of Wine, this time in dlls/comctl32/imagelist.c. It resulted in an AV (this time, after Wine has initialized its signal handlers). A .ll file will be attached (I don't have it on hand at the moment). This happens at all optimization levels, so it has nothing to do with the optimization passes. This also has nothing to do with the integrated assembler, since the resulting code crashes even with it turned off.

The backtrace attached to Wine bug 26754 shows it happens in ImageList_DrawEx(), so I suspect that that is the function that is miscompiled. I wish I had more information, but I don't.

[llvmbot]

imagelist.ll, bzip2 -9'ed
This was with clang 2.9, though I get the same with trunk. This is a regression from 2.8, where this works.

Running wine test suite shows around 62 similar crashes.

[llvmbot]

Regression testing indicates:
ee477b3c6116361d352643cb92b9ccfb92baf8d6 is the first bad commit
commit ee477b3c6116361d352643cb92b9ccfb92baf8d6
Author: Eric Christopher echristo@apple.com
Date: Thu Jan 13 06:47:10 2011 +0000

Experiment with changing the default 32-bit linux stack alignment to
16 bytes for llvm/llvm-project#9341 . Update all testcases accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123367 91177308-0d34-0410-b5e6-96231b3b80d8

:040000 040000 7c40b9f3a90480b44f1ff453cccea3c9d5e8dd33 bb6337de0f51d8cbc7565a40c6d9efd8657be00a M lib
:040000 040000 33a6541f957d0013c11141940ea0f005b1c1f365 2f9f28bc203bbe57f1fc1a1018d95d5d8f518c56 M test

[echristo]

Undoubtedly due to the fact that Windows defaults to 4-byte alignment for their stack frames. If you default wine to 4-byte frames it'll probably work?

[llvmbot]

Actually, defaulting Wine to 16-byte aligned frames works. Austin added the force_align_arg_pointer attribute to Wine's exported functions, and this fixed the crashes. (Well, as of this writing, it fixed the comctl32 crash. Still waiting for him to see if it fixed the other 62 crashes.)

[llvmbot]

Yeah, force_align_arg_pointer fixed about 50 of the other crashes.

[echristo]

Or defaulting that direction... :)

[llvmbot]

Well, since most of the crashes were fixed with a small change to Wine, I'm closing the bug.