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

Richard Guenther richard.guenther@gmail.com
Sat Jan 3 00:22:00 GMT 2009


On Sat, Jan 3, 2009 at 12:49 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> 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?

Ok.

Thanks,
Richard.

> 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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