maybe a bug in gcc 4.8 triggered with libdrm

[Andreas Radke]

I've bisected gcc from 4.7.3 to broken 4.8.1 and found this commit
braking libdrm/nouveau for me:
http://gcc.gnu.org/git/?p=gcc.git;a=commit;h=32b227ebedc3dde524cdbb3bfa7ccbca23e2a185

>From that commit on I see glitches on Firefox tabs and dmesg telling things like:

nouveau E[   PFIFO][0000:01:00.0] DMA_PUSHER - ch 1 [X[522]] get 0xbeef0200 put 0x00020dd4 state 0xc002018c ...0x00000000
nouveau E[  X[522]] reloc wait_idle failed: -16
nouveau E[  X[522]] reloc apply: -16

This quickly leads to desktop crashes.

Maybe someone knows more if this gcc commit does something wrong or if
code in libdrm is broken.

Later code in /gcc/gimplify.c changed a lot. A simple patch -R doesn't
work.

Any suggestions welcome.

CC'ing the patch author and some libdrm/nouveau people.

PS: I will soon replace that old nv44 card with a radeon card. Then I
won't be able to reproduce it anymore.

-Andy
ArchLinux