[Bug tree-optimization/15743] New: Fold index() at tree level.

[kazu at cs dot umass dot edu]

char *
foo (void)
{
  const char *s = "abcd";
  int c = 'p';
  return index (s, c);
}

I get:

foo ()
{
  int c;
  const char * s;
  char * T.0;

<bb 0>:
  T.0_3 = index ("abcd", 112) [tail call];
  return T.0_3;

}

The fix is pretty easy.

Index: builtins.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/builtins.c,v
retrieving revision 1.328
diff -u -r1.328 builtins.c
--- builtins.c  30 May 2004 21:05:20 -0000      1.328
+++ builtins.c  31 May 2004 06:44:31 -0000
@@ -7837,6 +7837,7 @@
     case BUILT_IN_STRNCPY:
       return fold_builtin_strncpy (exp);
                                                                               
                              
+    case BUILT_IN_INDEX:
     case BUILT_IN_STRCHR:
       return fold_builtin_strchr (exp, false);
                                                                               
                              

I'll post the patch to gcc-patches after testing it.

-- 
           Summary: Fold index() at tree level.
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kazu at cs dot umass dot edu
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15743