* alias.c (nonlocal_reference_p): Take a care for

	CALL_INSNS's fusage field.
	* calls.c (ECF_PURE): New flag.
	(emit_call_1): Handle ECF_PURE calls.
	(initialize_argument_information): Unset ECF_PURE flag too.
	(precompute_arguments): Precompute for ECF_PURE too.
	(expand_call): Handle ECF_PURE calls too.
	(emit_library_call_value_1): Rename no_queue argument to
	fn_type, accept value of 2 as pure function.
	(emit_library_call_value, emit_library_call): Rename no_queue argument
	to fn_type.
	* optabs.c (prepare_cmp_insn): Pass fn_type 2 to memcmp call.

	* tree.h (DECL_IS_PURE): New macro.
	(struct tree_decl): Add pure_flag.
	* c-common.c (enum attrs): Add attribute "pure".
	(init_attributes): Initialize attribute "pure"
	(decl_attributes): Handle attribute "pure".
	* extend.texi (Attribute "pure"): Document.
	* calls.c (expand_call): Add (mem:BLK (scratch)) to "equal from"
	in pure function.
	(flags_from_decl_or_type): Support attribute "pure".


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@33138 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 9 insertions, 4 deletions

diff --git a/gcc/alias.c b/gcc/alias.c
index db89ecc173e..fb493f8e7b0 100644
--- a/gcc/alias.c
+++ b/gcc/alias.c
@@ -1424,10 +1424,15 @@ nonlocal_reference_p (x)
 
   if (GET_RTX_CLASS (code) == 'i')
     {
-      /* Constant functions are constant.  */
+      /* Constant functions can be constant if they don't use
+         scratch memory used to mark function w/o side effects.  */
       if (code == CALL_INSN && CONST_CALL_P (x))
-	return 0;
-      x = PATTERN (x);
+        {
+	  x = CALL_INSN_FUNCTION_USAGE (x);
+	  if (!x) return 0;
+        }
+      else
+        x = PATTERN (x);
       code = GET_CODE (x);
     }
 
@@ -1520,7 +1525,7 @@ nonlocal_reference_p (x)
     
     for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
       {
-	if (fmt[i] == 'e')
+	if (fmt[i] == 'e' && XEXP (x, i))
 	  {
 	    if (nonlocal_reference_p (XEXP (x, i)))
 	      return 1;