[Bug c++/97642] New: Incorrect replacement of vmovdqu32 with vpblendd can cause fault

[goldstein.w.n at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97642

            Bug ID: 97642
           Summary: Incorrect replacement of vmovdqu32 with vpblendd can
                    cause fault
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: goldstein.w.n at gmail dot com
  Target Milestone: ---

GCC sometimes replaces 

_mm256_mask_loadu_epi32(__m256i src, __mask8 k, void const * mem_addr) //
vmovdqu32

With

vpblendd

If mem_addr points to a memory region with less than 32 bytes of accessible
memory and k is a mask that would prevent reading the inaccessible bytes from
mem_addr the replacement will cause a fault.

See: https://godbolt.org/z/Y5cTxz