[m-rev.] diff: fix GCC labels with GCC 4.9 on x86_64

[Julien Fischer]

Actually, it turns out that I fixed this bug on the master
branch several months ago, but didn't apply the fix to the release
branch.

Cheers,
Julien.


On Thu, 19 Feb 2015, Julien Fischer wrote:

>
> Branches 14.01, master
>
> ---------------------------
>
> Fix GCC labels with GCC 4.9 on x86_64.
>
> configure.ac:
>    Disable GCC's -ftree-dominator-opts optimization when using
>    GCC 4.9 on the x86_64 and x86.  As with GCC 4.8, its use seems
>    incompatible with our use of GCC labels.
>
> diff --git a/configure.ac b/configure.ac
> index da28e43..78159b6 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -2553,11 +2553,12 @@ case "$ac_cv_prog_gcc" in yes)
>             CFLAGS_FOR_GOTOS="$CFLAGS_FOR_GOTOS -fomit-frame-pointer"
>             ;;
>         i*86-*|x86_64*)
> -            # On x86-64 with GCC 4.8, gcc labels do not work correctly with
> -            # -ftree-dominator-opts -- we disable it for x86 in this case 
> too.
> +            # On x86-64 with GCC 4.8 and 4.9, gcc labels do not work 
> correctly
> +            # with -ftree-dominator-opts -- we disable it for x86 in this 
> case
> +            # too.
>             #
>             case "$C_COMPILER_TYPE" in
> -                gcc_4_8_*)
> +                gcc_4_8_*|gcc_4_9_*)
>                   CFLAGS_FOR_GOTOS="$CFLAGS_FOR_GOTOS 
> -fno-tree-dominator-opts"
>                 ;;
>             esac
>