Bug 698058

Summary:	media-libs/libsdl2 USE=cpu_flags_ppc_altivec on ppc64le results in color corruption
Product:	Gentoo Linux	Reporter:	Robert Bridge <robert>
Component:	Current packages	Assignee:	Gentoo Games <games>
Status:	UNCONFIRMED ---
Severity:	normal	CC:	jstein
Priority:	Normal
Version:	unspecified
Hardware:	PPC64
OS:	Linux
See Also:	https://bugzilla.libsdl.org/show_bug.cgi?id=4834 https://github.com/libsdl-org/SDL/issues/3428
Whiteboard:
Package list:		Runtime testing required:	---

Description Robert Bridge 2019-10-19 22:00:13 UTC

When media-libs/libsdl-1.2.15-r9 is compiled with the altivec use-flag set on ppc64le, color corruption is observed in wesnoth (and presumably other libsdl2 consumers). When it is compiled with -altivec, the color corruption goes away.

Reproducible: Always

Steps to Reproduce:
1. Compile media-libs/libsdl2 with altivec set on ppc64le
2. Run Wesnoth
3. Observe the corrupted colors
Actual Results:  
Corrupted colors observed in wesnoth

Expected Results:  
No corrupted colors

No corrupted colors observed on same platform with only media-libs/libsdl2 recompiled without altivec.

Comment 1 Robert Bridge 2019-10-20 00:07:21 UTC

Ok, I was pulling wrong information when I posted the report... It should have been media-libs/libsdl2-2.0.10 listed, not the libsdl1 version. My apologies.

Comment 2 James Le Cuirot gentoo-dev

2019-10-20 11:36:03 UTC

Being somewhat obscure hardware, I can't easily test this myself and it is almost certainly an upstream bug anyway. Could you please report it there and link it here?

Comment 3 Robert Bridge 2019-10-20 12:12:32 UTC

Would it be practical to package.use.mask altivec for ppc64le as a temporary workaround?

Comment 4 Robert Bridge 2019-10-20 12:37:00 UTC

Reported upstream https://bugzilla.libsdl.org/show_bug.cgi?id=4834