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[Patch, PR 57811] Wasted work in find_reloads()


Hi,

The problem appears in revision 201034 in version 4.9.  I attached
one-line patches that fixes it.  I also reported this problem
at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57811

Bootstrap and regression-tested on x86_64-linux.

In method "find_reloads()" in gcc/reload.c, the loop on line 3324  should
break immediately after "badop" is set to "1". Also, the loop on line 4641
 should break after "ok" is set to "0".


2013-07-22  Chang  <pchang9@cs.wisc.edu>

        * reload.c (find_reloads): Exit loop once we find this operand
          cannot be reloaded somehow for this alternative.

        * reload.c (find_reloads): Exit loop once we find a
          hard register.



Index: gcc/reload.c
===================================================================
--- gcc/reload.c	(revision 201034)
+++ gcc/reload.c	(working copy)
@@ -3324,7 +3324,10 @@
 		      for (j = 0; j < i; j++)
 			if (this_alternative_matches[j]
 			    == this_alternative_matches[i])
-			  badop = 1;
+			  {
+			    badop = 1;
+			    break;
+			  }
 		    break;

 		  case 'p':
Index: gcc/reload.c
===================================================================
--- gcc/reload.c	(revision 201034)
+++ gcc/reload.c	(working copy)
@@ -4640,7 +4640,10 @@

 	    for (nri = 1; nri < nr; nri ++)
 	      if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno
+ nri))
-		ok = 0;
+		{
+		  ok = 0;
+		  break;
+		}

 	    if (ok)
 	      rld[i].reg_rtx = dest;

-Chang

Attachment: pr57811_patch1.diff
Description: Text document

Attachment: pr57811_patch2.diff
Description: Text document


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