[Bug target/67322] New: [Aarch64] Exploit Wide Add operations when appropriate

["michael.collison at linaro dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67322

            Bug ID: 67322
           Summary: [Aarch64] Exploit Wide Add operations when appropriate
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: michael.collison at linaro dot org
  Target Milestone: ---

Wide add operations are not always being generated for mixed mode adds as shown
by the following test case:

int wadd_test(int len, void * dummy, short * __restrict x)
{
  len = len & ~31;
  int result = 0;
  __asm volatile ("");
  for (int i = 0; i < len; i++)
    result += x[i];
  return result;
}