Feb 8 14:56:03 1998 Richard Kenner <kenner@vlsi1.ultra.nyu.edu>

Feb  8 14:56:03 1998  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
        * loop.c (strength_reduce): When placing increment for auto-inc
        case, do comparison in loop order.

From-SVN: r17781

gcc/ChangeLog

+Sun Feb  8 14:56:03 1998  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
+
+	* loop.c (strength_reduce): When placing increment for auto-inc
+	case, do comparison in loop order.
+	
 Sun Feb  8 13:21:38 1998  John Carr  <jfc@mit.edu>
 
 	* bitmap.c (bitmap_debug_file): HOST_PTR_PRINTF converts a pointer,

gcc/loop.c

@@ -4114,8 +4114,14 @@ strength_reduce (scan_start, end, loop_top, insn_count,
 			auto_inc_opt = 1;
 		    }
 		  /* Check for case where increment is before the the address
-		     giv.  */
-		  else if (INSN_LUID (v->insn) > INSN_LUID (bl->biv->insn))
+		     giv.  Do this test in "loop order".  */
+		  else if ((INSN_LUID (v->insn) > INSN_LUID (bl->biv->insn)
+			    && (INSN_LUID (v->insn) < INSN_LUID (scan_start)
+				|| (INSN_LUID (bl->biv->insn)
+				    > INSN_LUID (scan_start))))
+			   || (INSN_LUID (v->insn) < INSN_LUID (scan_start)
+			       && (INSN_LUID (scan_start)
+				   < INSN_LUID (bl->biv->insn))))
 		    auto_inc_opt = -1;
 		  else
 		    auto_inc_opt = 1;