[Bug tree-optimization/99504] New: Missing memmove detection

[crazylht at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99504

            Bug ID: 99504
           Summary: Missing memmove detection
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: crazylht at gmail dot com
                CC: hjl.tools at gmail dot com
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu

cat test.c

typedef struct
{
    unsigned char r,g,b,c;
}pixel;

void
foo_memmov (pixel* p, pixel* q, int n)
{
    for (int i = 0; i != n; i++)
      *p++ = *q++; 
}

void
foo_int (int* p, int* q, int n)
{
    for (int i = 0; i != n; i++)
      *p++ = *q++; 
}

gcc -Ofast -march=skylake

https://godbolt.org/z/hbnTfM

1. Not memmov optimization
2. Why didn't vectorizer optimize foo_memmov like foo_int did.