tree-ssa-operands.c (get_expr_operands): Do not treat malloc attributed functions as pure or const.

	* tree-ssa-operands.c (get_expr_operands): Do not treat malloc
	attributed functions as pure or const.

From-SVN: r81951

gcc/ChangeLog

+2004-05-17  Steven Bosscher  <stevenb@suse.de>
+
+	* tree-ssa-operands.c (get_expr_operands): Do not treat malloc
+	attributed functions as pure or const.
+
 2004-05-17  Frank Ch. Eigler  <fche@redhat.com>
 
 	* tree-mudflap.c (mx_register_decls): Tolerate decl trees resulting

gcc/testsuite/ChangeLog

+2004-05-17  Steven Bosscher  <stevenb@suse.de>
+
+	* gcc.dg/tree-ssa/20040517-1.c: New test.
+
 2004-05-15  Andrew Pinski  <pinskia@physics.uc.edu>
 
 	* gcc.dg/tree-ssa/20040514-1.c: Add '}' that was forgotten.

gcc/testsuite/gcc.dg/tree-ssa/20040517-1.c

+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-ssa-vops" } */
+int a; 
+ 
+extern void __attribute__ ((malloc)) *foo ();
+ 
+void bar (void) 
+{ 
+  a = 1; 
+  foo (); 
+  if (a) 
+    abort (); 
+} 
+
+/* We used to treat malloc functions like pure and const functions, but
+   malloc functions may clobber global memory.  Only the function result
+   does not alias any other pointer.
+   Hence, we must have a VDEF for a before and after the call to foo().  */
+/* { dg-final { scan-tree-dump-times "VDEF" 2 "ssa"} } */
+

gcc/tree-ssa-operands.c

@@ -1023,12 +1023,11 @@ get_expr_operands (tree stmt, tree *expr_p, int flags, voperands_t prev_vops)
 
       if (bitmap_first_set_bit (call_clobbered_vars) >= 0)
 	{
+	  /* A 'pure' or a 'const' functions never call clobber anything. 
+	     A 'noreturn' function might, but since we don't return anyway 
+	     there is no point in recording that.  */ 
 	  if (!(call_flags
-		& (ECF_PURE
-		   | ECF_CONST
-		   | ECF_NORETURN
-		   | ECF_MALLOC
-		   | ECF_MAY_BE_ALLOCA)))
+		& (ECF_PURE | ECF_CONST | ECF_NORETURN)))
 	    add_call_clobber_ops (stmt, prev_vops);
 	  else if (!(call_flags & (ECF_CONST | ECF_NORETURN)))
 	    add_call_read_ops (stmt, prev_vops);