https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109982
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Uroš Bizjak from comment #1) > Also fails with "-mtune=znver1 -mavx": > > Program received signal SIGSEGV, Segmentation fault. > 0x00000000004048ef in func_21 (p_22=0x41b330 <g_277>, p_23=0, p_24=8) at > runData/keep/in.11.c:597 > 597 in runData/keep/in.11.c > (gdb) disass $pc-10, $pc+10 > Dump of assembler code from 0x4048e5 to 0x4048f9: > 0x00000000004048e5 <func_21+8160>: mov (%rax),%rdx > 0x00000000004048e8 <func_21+8163>: mov -0x1378(%rbp),%rax > => 0x00000000004048ef <func_21+8170>: vmovdqa (%rdx),%ymm0 > 0x00000000004048f3 <func_21+8174>: vmovdqa %ymm0,(%rax) > 0x00000000004048f7 <func_21+8178>: vmovdqa 0x20(%rdx),%ymm0 > End of assembler dump. > (gdb) p/x $rdx > $3 = 0x41a824 > > Unaligned access. After some more analysis, the above *IS* unaligned access. At the end of func_21, we have: => 0x00000000004048ef <+8170>: vmovdqa (%rdx),%ymm0 0x00000000004048f3 <+8174>: vmovdqa %ymm0,(%rax) 0x00000000004048f7 <+8178>: vmovdqa 0x20(%rdx),%ymm0 0x00000000004048fc <+8183>: vmovdqa %ymm0,0x20(%rax) 0x0000000000404901 <+8188>: vmovdqa 0x40(%rdx),%ymm0 0x0000000000404906 <+8193>: vmovdqa %ymm0,0x40(%rax) 0x000000000040490b <+8198>: vmovdqa 0x60(%rdx),%ymm0 0x0000000000404910 <+8203>: vmovdqa %ymm0,0x60(%rax) which looks like a memory copy to me. Unfortunately, the address is unaligned: (gdb) p/x $rdx $2 = 0x41a824 Changing the above vmovdqa insns to vmovdqu results in a successful run.
