[Bug tree-optimization/93080] New: insert of an extraction on the same location is not optimized

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93080

            Bug ID: 93080
           Summary: insert of an extraction on the same location is not
                    optimized
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: missed-optimization, TREE
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: pinskia at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

testcase:
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
#define vector __attribute__((__vector_size__(16) ))


vector int g(vector int a)
{
  int b = a[0];
  a[0] = b;
  return a;
}

/* { dg-final { scan-tree-dump-times "BIT_INSERT_EXPR" 0 "optimized" } } */
/* { dg-final { scan-tree-dump-times "BIT_FIELD_REF" 0 "optimized" } } */
---- CUT ----