alias.c (memrefs_conflict_p): If x and y are the same VALUE, don't call get_addr on both.

	* alias.c (memrefs_conflict_p): If x and y are the same VALUE,
	don't call get_addr on both.  If one expression is a VALUE and
	the other a REG, check VALUE's locs if the REG isn't among them.

From-SVN: r158401

gcc/ChangeLog

+2010-04-16  Jakub Jelinek  <jakub@redhat.com>
+
+	* alias.c (memrefs_conflict_p): If x and y are the same VALUE,
+	don't call get_addr on both.  If one expression is a VALUE and
+	the other a REG, check VALUE's locs if the REG isn't among them.
+
 2010-04-16  Christian Bruel  <christian.bruel@st.com>
 
 	* config/sh/sh.h (sh_frame_pointer_required): New function.

gcc/alias.c

@@ -1789,9 +1789,39 @@ static int
 memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
 {
   if (GET_CODE (x) == VALUE)
-    x = get_addr (x);
+    {
+      if (REG_P (y))
+	{
+	  struct elt_loc_list *l;
+	  for (l = CSELIB_VAL_PTR (x)->locs; l; l = l->next)
+	    if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y))
+	      break;
+	  if (l)
+	    x = y;
+	  else
+	    x = get_addr (x);
+	}
+      /* Don't call get_addr if y is the same VALUE.  */
+      else if (x != y)
+	x = get_addr (x);
+    }
   if (GET_CODE (y) == VALUE)
-    y = get_addr (y);
+    {
+      if (REG_P (x))
+	{
+	  struct elt_loc_list *l;
+	  for (l = CSELIB_VAL_PTR (y)->locs; l; l = l->next)
+	    if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x))
+	      break;
+	  if (l)
+	    y = x;
+	  else
+	    y = get_addr (y);
+	}
+      /* Don't call get_addr if x is the same VALUE.  */
+      else if (y != x)
+	y = get_addr (y);
+    }
   if (GET_CODE (x) == HIGH)
     x = XEXP (x, 0);
   else if (GET_CODE (x) == LO_SUM)