Mark __builtin_constant_p as constant [patch]

[Diego Novillo]

Since __builtin_constant_p is not marked constant, the tree ssa
optimizers were getting confused when calls to
__builtin_constant_p were being folded away.  I don't think the
patch affects anything in mainline but it's needed for tree-ssa.

Bootstrapped and tested on x86.  It also works on ppc and x86-64
on the ssa branch.  OK for mainline?


Diego.



	* builtins.def (BUILTIN_CONSTANT_P): Mark as constant.

Index: builtins.def
===================================================================
RCS file: /cvs/gcc/gcc/gcc/builtins.def,v
retrieving revision 1.49
diff -d -u -p -r1.49 builtins.def
--- builtins.def	28 Apr 2003 12:10:30 -0000	1.49
+++ builtins.def	29 Apr 2003 19:05:09 -0000
@@ -689,7 +689,7 @@ DEF_GCC_BUILTIN(BUILT_IN_ARGS_INFO,
 DEF_GCC_BUILTIN(BUILT_IN_CONSTANT_P, 
 		"__builtin_constant_p", 
 		BT_FN_INT_VAR,
-		ATTR_NULL)
+		ATTR_CONST_NOTHROW_LIST)
 DEF_GCC_BUILTIN(BUILT_IN_FRAME_ADDRESS,
 		"__builtin_frame_address",
 		BT_FN_PTR_UNSIGNED,