[PATCH] Fix __builtin_expect folding (PR c/38700)

Jakub Jelinek jakub@redhat.com
Fri Jan 2 23:50:00 GMT 2009


Hi!

DECL_WEAK can only be used with VAR_DECL, FUNCTION_DECL, TYPE_DECL
and TRANSLATION_UNIT_DECL, the latter 2 IMHO can't occur inside of
ADDR_EXPR.  DECL_P also matches LABEL_DECL, PARM_DECL etc.

Fixed thusly, bootstrapped/regtested on x86_64-linux.  Ok for trunk?

2009-01-03  Jakub Jelinek  <jakub@redhat.com>

	PR c/38700
	* builtins.c (fold_builtin_expect): Only check DECL_WEAK for VAR_DECLs
	and FUNCTION_DECLs.

	* gcc.dg/pr38700.c: New test.

--- gcc/builtins.c.jj	2008-12-27 10:12:25.000000000 +0100
+++ gcc/builtins.c	2009-01-02 16:06:03.000000000 +0100
@@ -1,6 +1,6 @@
 /* Expand builtin functions.
    Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -7324,7 +7324,9 @@ fold_builtin_expect (tree arg0, tree arg
 	}
       while (TREE_CODE (inner) == COMPONENT_REF
 	     || TREE_CODE (inner) == ARRAY_REF);
-      if (DECL_P (inner) && DECL_WEAK (inner))
+      if ((TREE_CODE (inner) == VAR_DECL
+           || TREE_CODE (inner) == FUNCTION_DECL)
+	  && DECL_WEAK (inner))
 	return NULL_TREE;
     }
 
--- gcc/testsuite/gcc.dg/pr38700.c.jj	2009-01-02 16:05:19.000000000 +0100
+++ gcc/testsuite/gcc.dg/pr38700.c	2009-01-02 16:05:05.000000000 +0100
@@ -0,0 +1,11 @@
+/* PR c/38700 */
+/* { dg-do compile } */
+/* { dg-options "-O0" } */
+
+int
+foo ()
+{
+  __SIZE_TYPE__ s = __builtin_expect ((__SIZE_TYPE__)&&L, 0);
+L:
+  return 0;
+}

	Jakub



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