https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83735
Bug ID: 83735 Summary: [8 Regression] generating unaligned store to stack with vmovaps Product: gcc Version: 8.0 Status: UNCONFIRMED Keywords: wrong-code Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: zsojka at seznam dot cz Target Milestone: --- Host: x86_64-pc-linux-gnu Target: x86_64-pc-linux-gnu Created attachment 43058 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=43058&action=edit reduced testcase Similar to PR78585 and PR83330, but this one is for different target and needs a very small set of flags to reproduce. This particular testcase does not fail in gcc-7, but it might be just a luck. Output: $ x86_64-pc-linux-gnu-gcc -O3 -mavx512bw testcase.c $ ./a.out Segmentation fault The failing instruction is: 0x00000000004003c4 <+52>: vmovdqu 0x200cb4(%rip),%xmm1 # 0x601080 <j> 0x00000000004003cc <+60>: vmovdqa 0x4ec(%rip),%ymm0 # 0x4008c0 => 0x00000000004003d4 <+68>: vmovaps %xmm1,-0x30(%rsp) 0x00000000004003da <+74>: vmovdqu 0x200cae(%rip),%xmm1 # 0x601090 <j+16> 0x00000000004003e2 <+82>: mov 0x200cb7(%rip),%rax # 0x6010a0 <j+32> (gdb) p $rsp $1 = (void *) 0x7fffffffd678 rsp-0x30 is not correctly aligned. $ x86_64-pc-linux-gnu-gcc -v Using built-in specs. COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-256323-checking-yes-rtl-df-extra-nographite-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/8.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++ --enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra --without-cloog --without-ppl --without-isl --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld --with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch --prefix=/repo/gcc-trunk//binary-trunk-256323-checking-yes-rtl-df-extra-nographite-amd64 Thread model: posix gcc version 8.0.0 20180107 (experimental) (GCC)