Bug 291568 - Fix 3DNOW-related crashes with baseline x86_64 CPU
Summary: Fix 3DNOW-related crashes with baseline x86_64 CPU
Status: RESOLVED FIXED
Alias: None
Product: valgrind
Classification: Developer tools
Component: vex (other bugs)
Version First Reported In: 3.7 SVN
Platform: Debian unstable Linux
: NOR normal
Target Milestone: ---
Assignee: Julian Seward
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-01-15 10:36 UTC by Reimar Döffinger
Modified: 2012-02-21 08:59 UTC (History)
0 users

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:

Attachments
Remove 3dnow support bits from CPUID (682 bytes, patch)
2012-01-15 10:36 UTC, Reimar Döffinger 		Details
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Description Reimar Döffinger 2012-01-15 10:36:17 UTC 
Created attachment 67842 [details]
Remove 3dnow support bits from CPUID

Currently the CPUID values for this are based on a real CPU.
Unfortunately, it is an AMD CPU.
This means that CPUID claims to support 3DNOW while it actually doesn't.
As a result, any program doing audio decoding with FFmpeg crashes in valgrind in x86_64 mode.
Attached patch just hacks the CPUID a bit to remove the 3DNOW flags.
That is not perfect since it now matches no real CPU but claiming to support a feature that will certainly crash is surely worse.
Comment 1 Reimar Döffinger 2012-02-20 20:41:09 UTC 
Sorry to be impatient, but I'd appreciate if someone could have a look. This is a really old issue I got finally annoyed enough about to debug (as a MPlayer/FFmpeg developer using an AMD CPU it is really annoying when valgrind crashes the program you're debugging half the time).
Comment 2 Julian Seward 2012-02-21 08:59:11 UTC 
Committed w/ extra comments, r2259.  Thanks.