alias.c (find_base_term, get_addr): Do not dereference NULL pointer when all…

alias.c (find_base_term, get_addr): Do not dereference NULL pointer when all VALUE's locations has been invalidated.

	* alias.c (find_base_term, get_addr):  Do not dereference NULL
	pointer when all VALUE's locations has been invalidated.
	(rtx_equal_for_memref_p): Simplify checking of VALUEs.

From-SVN: r77201

gcc/ChangeLog

+2004-02-04  Jan Hubicka  <jh@suse.cz>
+
+	* alias.c (find_base_term, get_addr):  Do not dereference NULL
+	pointer when all VALUE's locations has been invalidated.
+	(rtx_equal_for_memref_p): Simplify checking of VALUEs.
+
 2004-02-03  Wolfgang Bangerth  <bangerth@dealii.org> 
 
 	* doc/invoke.texi (x86 options): Fix spelling/wording.

gcc/alias.c

@@ -1139,9 +1139,6 @@ rtx_equal_for_memref_p (rtx x, rtx y)
   /* Some RTL can be compared without a recursive examination.  */
   switch (code)
     {
-    case VALUE:
-      return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y);
-
     case REG:
       return REGNO (x) == REGNO (y);
 
@@ -1151,6 +1148,7 @@ rtx_equal_for_memref_p (rtx x, rtx y)
     case SYMBOL_REF:
       return XSTR (x, 0) == XSTR (y, 0);
 
+    case VALUE:
     case CONST_INT:
     case CONST_DOUBLE:
       /* There's no need to compare the contents of CONST_DOUBLEs or
@@ -1325,6 +1323,8 @@ find_base_term (rtx x)
 
     case VALUE:
       val = CSELIB_VAL_PTR (x);
+      if (!val)
+	return 0;
       for (l = val->locs; l; l = l->next)
 	if ((x = find_base_term (l->loc)) != 0)
 	  return x;
@@ -1502,14 +1502,17 @@ get_addr (rtx x)
   if (GET_CODE (x) != VALUE)
     return x;
   v = CSELIB_VAL_PTR (x);
-  for (l = v->locs; l; l = l->next)
-    if (CONSTANT_P (l->loc))
-      return l->loc;
-  for (l = v->locs; l; l = l->next)
-    if (GET_CODE (l->loc) != REG && GET_CODE (l->loc) != MEM)
-      return l->loc;
-  if (v->locs)
-    return v->locs->loc;
+  if (v)
+    {
+      for (l = v->locs; l; l = l->next)
+	if (CONSTANT_P (l->loc))
+	  return l->loc;
+      for (l = v->locs; l; l = l->next)
+	if (GET_CODE (l->loc) != REG && GET_CODE (l->loc) != MEM)
+	  return l->loc;
+      if (v->locs)
+	return v->locs->loc;
+    }
   return x;
 }