[Patch, PR 57787] Wasted work in ix86_pad_returns()

[pchang9]

Hi,

The problem appears in revision 201034 in version 4.9. I also reported
this problem at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57787.

Bootstrap and regression-tested on x86_64-linux.

In method "ix86_pad_returns()" in i386.c, the loop on line 35723 should
break immediately after "replace" is set to "true".


2013-07-22  Chang  <pcha...@cs.wisc.edu>

        * i386.c (ix86_pad_returns): Exit loop after setting replace.


Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c      (revision 201034)
+++ gcc/config/i386/i386.c      (working copy)
@@ -35723,7 +35723,10 @@
          FOR_EACH_EDGE (e, ei, bb->preds)
            if (EDGE_FREQUENCY (e) && e->src->index >= 0
                && !(e->flags & EDGE_FALLTHRU))
-             replace = true;
+             {
+               replace = true;
+               break;
+             }
        }
       if (!replace)
        {


-Chang