fix fold_builtin wrt rtl-level state

[Richard Henderson <rth at redhat dot com>]

cse_not_expected is an rtl-level concept; we have no business 
checking it here.  With some changes that I'm working on, it
isn't necessarily initialized when fold_builtin is called.


r~


        * builtins.c (expand_builtin_constant_p): Check cse_not_expected here,
        (fold_builtin_constant_p) ... not here.

Index: builtins.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/builtins.c,v
retrieving revision 1.245
diff -c -p -d -u -r1.245 builtins.c
--- builtins.c	29 Aug 2003 17:03:13 -0000	1.245
+++ builtins.c	29 Aug 2003 22:06:05 -0000
@@ -1462,7 +1462,11 @@ expand_builtin_constant_p (tree arglist,
 
   /* We have taken care of the easy cases during constant folding.  This
      case is not obvious, so emit (constant_p_rtx (ARGLIST)) and let CSE
-     get a chance to see if it can deduce whether ARGLIST is constant.  */
+     get a chance to see if it can deduce whether ARGLIST is constant.
+     If CSE isn't going to run, of course, don't bother waiting.  */
+
+  if (cse_not_expected)
+    return const0_rtx;
 
   current_function_calls_constant_p = 1;
 
@@ -5470,15 +5474,14 @@ fold_builtin_constant_p (tree arglist)
 	  && TREE_CODE (TREE_OPERAND (arglist, 0)) == STRING_CST))
     return integer_one_node;
 
-  /* If we aren't going to be running CSE or this expression
-     has side effects, show we don't know it to be a constant.
-     Likewise if it's a pointer or aggregate type since in those
-     case we only want literals, since those are only optimized
+  /* If this expression has side effects, show we don't know it to be a
+     constant.  Likewise if it's a pointer or aggregate type since in
+     those case we only want literals, since those are only optimized
      when generating RTL, not later.
      And finally, if we are compiling an initializer, not code, we
      need to return a definite result now; there's not going to be any
      more optimization done.  */
-  if (TREE_SIDE_EFFECTS (arglist) || cse_not_expected
+  if (TREE_SIDE_EFFECTS (arglist)
       || AGGREGATE_TYPE_P (TREE_TYPE (arglist))
       || POINTER_TYPE_P (TREE_TYPE (arglist))
       || cfun == 0)