[Bug target/62642] [4.8/4.9/5 Regression] x86 rdtsc is moved through barrier
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62642 Jakub Jelinek jakub at gcc dot gnu.org changed: What|Removed |Added Target Milestone|4.8.4 |4.8.5 --- Comment #6 from Jakub Jelinek jakub at gcc dot gnu.org --- GCC 4.8.4 has been released.
[Bug target/62642] [4.8/4.9/5 Regression] x86 rdtsc is moved through barrier
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62642 --- Comment #5 from M8R-ynb11d at mailinator dot com --- I originally put the barriers there in a futile attempt to work around the bug. Can anyone tell me whether I actually need them, or whether the intrinsic carries with it an implicit built-in barrier to prevent reordering? Ideally I'd like to write portable code using only intrinsics and not gcc-specific asm() stuff, so I hope that it's the latter.
[Bug target/62642] [4.8/4.9/5 Regression] x86 rdtsc is moved through barrier
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62642 --- Comment #4 from Vladimir Makarov vmakarov at gcc dot gnu.org --- Author: vmakarov Date: Mon Dec 15 20:04:04 2014 New Revision: 218761 URL: https://gcc.gnu.org/viewcvs?rev=218761root=gccview=rev Log: 2014-12-15 Vladimir Makarov vmaka...@redhat.com PR target/62642 * ira.c (rtx_moveable_p): Prevent UNSPEC_VOLATILE moves. Modified: trunk/gcc/ChangeLog trunk/gcc/ira.c
[Bug target/62642] [4.8/4.9/5 Regression] x86 rdtsc is moved through barrier
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62642 --- Comment #3 from Vladimir Makarov vmakarov at gcc dot gnu.org --- The problem is in a live range splitting optimization to reduce register pressure. It was introduced by https://gcc.gnu.org/ml/gcc-patches/2011-12/msg01531.html It is easy to switch off for this kind of insns. I'll submit the patch on Monday.
[Bug target/62642] [4.8/4.9/5 Regression] x86 rdtsc is moved through barrier
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62642 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Keywords||ra Target||i?86-*-* Priority|P3 |P2 CC||vmakarov at gcc dot gnu.org Summary|[4.8/4.9 Regression] x86|[4.8/4.9/5 Regression] x86 |rdtsc is moved through |rdtsc is moved through |barrier |barrier --- Comment #2 from Richard Biener rguenth at gcc dot gnu.org --- Confirmed on trunk.
