Bug 374019 – qt-gui-4.7.2-r1 does not compile on x86 with mstackrealign CFLAG and gcc-4.4

• Status: RESOLVED NEEDINFO
• Product: Gentoo Linux

[Description Till Korten 2011-07-04 09:25:34 UTC]

Created attachment 279025 [details]
compile log

trying to compile qt-gui-4.7.2 on x86 with the following CFLAGS on an Athlon 330:
CFLAGS="-O2 -march=native -msse3 -mfpmath=sse -mstackrealign -pipe"

with these cflags it works nicely:
CFLAGS="-O2 -march=native -msse3 -mfpmath=sse -pipe"

however if I permanently disable mstackrealign, I get the infamous mozilla segfaults due to misaligned stacks (see bug #270120 and http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40838 ).

In these bugs it is also suggested that this error only occurs with the sse CFLAGS enabled, however I think for performance reasons it is better to disable mstackrealign than sse.

Therefore, I suggest to disable the mstackrealign flag in the qt-gui ebuild.
I also had the same problem with qt-scripts-4.6.3.

I attached the compile log and emerge --info

[Comment 1 Till Korten 2011-07-04 09:28:04 UTC]

Created attachment 279029 [details]
emerge --info

[Comment 2 Davide Pesavento (RETIRED) 2011-11-13 15:29:45 UTC]

Can you try with a more recent gcc please (e.g. 4.5.3-r1)?

[Comment 3 Till Korten 2011-11-13 16:15:37 UTC]

unfortunately, I migrated to new hardware (Core i3) and amd64 in the meantime. Therefore, I cannot test on the x86 platform. With 64 bit gcc 4.5.3-r1, qt-gui compiles fine (provided I use make -j1).

I hope someone else can test with a newer gcc and x86.

[Comment 4 Davide Pesavento (RETIRED) 2011-11-13 20:52:24 UTC]

Ok, I'm closing then. If someone else can reproduce this bug on x86 with a newer gcc, please leave a comment here and I'll reopen. Thanks.