[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 Uroš Bizjak changed: What|Removed |Added Status|NEW |RESOLVED Resolution|---

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #11 from Allan Jensen --- The think the issue I noted is completely separate from this one, so I opened https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78762 to deal with it. I think this one could probably be closed though.

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #10 from Allan Jensen --- No I mean it triggers when you compile with -mavx2, it is solved with -march=haswell. It appears the issue is the tune flag X86_TUNE_AVX256_UNALIGNED_LOAD_OPTIMAL is set for all processors that support avx2,

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #9 from Marc Glisse --- (In reply to Allan Jensen from comment #7) > This is significantly worse with integer operands. > > _mm256_storeu_si256((__m256i *)[3], > _mm256_add_epi32(_mm256_loadu_si256((const __m256i *)[0]), >

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #8 from Allan Jensen --- Note this happens with -mavx2, but not with -march=haswell. It appears the tuning is a bit too pessimistic when avx2 is enabled on generic x64.

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 Allan Jensen changed: What|Removed |Added CC||linux at carewolf dot com --- Comment #7

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #6 from Jakub Jelinek jakub at gcc dot gnu.org --- Author: jakub Date: Wed Oct 30 17:59:44 2013 New Revision: 204219 URL: http://gcc.gnu.org/viewcvs?rev=204219root=gccview=rev Log: PR target/47754 * config/i386/i386.c

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 xiaoyuanbo xiaoyuanbo at yeah dot net changed: What|Removed |Added CC||xiaoyuanbo at yeah

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added CC||rth at gcc

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Keywords|

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #2 from Matthias Kretz kretz at kde dot org 2011-02-15 16:31:39 UTC --- True, the Optimization Reference Manual and AVX Docs are not very specific about the performance impact of this. But as far as I understood the docs it will

[Bug target/47754] [missed optimization] AVX allows unaligned memory operands but GCC uses unaligned load and register operand

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47754 --- Comment #3 from Matthias Kretz kretz at kde dot org 2011-02-15 16:40:38 UTC --- ICC??? Whatever, I stopped to trust that compiler long ago: unaligned(): vmovups 0x2039b8(%rip),%xmm0 vmovups 0x2039b4(%rip),%xmm1 vinsertf128