[Bug optimization/15017] New: [tree-ssa] compare (equal) with casts are not removed

[pinskia at gcc dot gnu dot org]

On most targets where _Bool is of size 1 (everywhere except PPC-darwin), the following
code contains sign/zero extends which is bad code:

static _Bool as, bs;
_Bool foo3 (void) {
if (as != bs) return 1;
else  return 0;
}

Likewise for this code also:
static signed char as, bs;
_Bool foo3 (void) {
int as1 = as;
int bs1 = bs;
if (as1 != bs1) return 1;
else  return 0;
}

-- 
           Summary: [tree-ssa] compare (equal) with casts are not removed
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Keywords: pessimizes-code
          Severity: enhancement
          Priority: P2
         Component: optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pinskia at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15017