[PATCH 29/50] loop-iv.c:altered_reg_used

[Richard Sandiford <rdsandiford at googlemail dot com>]

gcc/
	* loop-iv.c (altered_reg_used): Turn from being a for_each_rtx callback
	to being a function that examines each subrtx itself.
	(simplify_using_condition, simplify_using_initial_values): Update
	accordingly.

Index: gcc/loop-iv.c
===================================================================
--- gcc/loop-iv.c	2014-08-03 11:25:27.978132785 +0100
+++ gcc/loop-iv.c	2014-08-03 11:25:28.247135444 +0100
@@ -1327,15 +1327,19 @@ inverse (uint64_t x, int mod)
   return rslt;
 }
 
-/* Checks whether register *REG is in set ALT.  Callback for for_each_rtx.  */
+/* Checks whether any register in X is in set ALT.  */
 
-static int
-altered_reg_used (rtx *reg, void *alt)
+static bool
+altered_reg_used (const_rtx x, bitmap alt)
 {
-  if (!REG_P (*reg))
-    return 0;
-
-  return REGNO_REG_SET_P ((bitmap) alt, REGNO (*reg));
+  subrtx_iterator::array_type array;
+  FOR_EACH_SUBRTX (iter, array, x, NONCONST)
+    {
+      const_rtx x = *iter;
+      if (REG_P (x) && REGNO_REG_SET_P (alt, REGNO (x)))
+	return true;
+    }
+  return false;
 }
 
 /* Marks registers altered by EXPR in set ALT.  */
@@ -1771,8 +1775,7 @@ simplify_using_condition (rtx cond, rtx
 
   /* If some register gets altered later, we do not really speak about its
      value at the time of comparison.  */
-  if (altered
-      && for_each_rtx (&cond, altered_reg_used, altered))
+  if (altered && altered_reg_used (cond, altered))
     return;
 
   if (GET_CODE (cond) == EQ
@@ -2048,7 +2051,7 @@ simplify_using_initial_values (struct lo
 	      /* If we did not use this insn to make a replacement, any overlap
 		 between stores in this insn and our expression will cause the
 		 expression to become invalid.  */
-	      if (for_each_rtx (expr, altered_reg_used, this_altered))
+	      if (altered_reg_used (*expr, this_altered))
 		goto out;
 
 	      /* Likewise for the conditions.  */
@@ -2058,7 +2061,7 @@ simplify_using_initial_values (struct lo
 		  rtx old_cond = XEXP (note, 0);
 
 		  pnote_next = &XEXP (note, 1);
-		  if (for_each_rtx (&old_cond, altered_reg_used, this_altered))
+		  if (altered_reg_used (old_cond, this_altered))
 		    {
 		      *pnote = *pnote_next;
 		      pnote_next = pnote;
@@ -2076,7 +2079,7 @@ simplify_using_initial_values (struct lo
 	     can't return it to the caller.  However, it is still valid for
 	     further simplification, so keep searching to see if we can
 	     eventually turn it into a constant.  */
-	  if (for_each_rtx (expr, altered_reg_used, altered))
+	  if (altered_reg_used (*expr, altered))
 	    expression_valid = false;
 	  if (expression_valid)
 	    last_valid_expr = *expr;