Re: [google/gcc-4_7] Backport arm hardfp patch from trunk

[Carrot Wei <carrot at google dot com>]

OK for google/gcc-4_7.

thanks
Carrot

On Tue, Aug 14, 2012 at 7:14 AM, Han Shen(ææ) <shenhan@google.com> wrote:
>
> Hi Carrot, could you take a look at this patch? Thanks!
>
> The modification is in upstream trunk patch revision - 186859.
>
> The same patch has been back ported to google/gcc-4_6
> (http://codereview.appspot.com/6206055/), this is to apply on
> google/gcc-4_7
>
> Regards,
> -Han
>
> 2012-08-13  Han Shen  <shenhan@google.com>
>
>         Backport from mainline.
>         2012-05-01  Richard Earnshaw  <rearnsha@arm.com>
>
>         * arm/linux-eabi.h (GLIBC_DYNAMIC_LINKER_DEFAULT): Avoid ifdef
>         comparing enumeration values.  Update comments.
>
>         2012-04-26  Michael Hope  <michael.hope@linaro.org>
>                     Richard Earnshaw  <rearnsha@arm.com>
>
>         * config/arm/linux-eabi.h (GLIBC_DYNAMIC_LINKER_SOFT_FLOAT):
> Define.
>         (GLIBC_DYNAMIC_LINKER_HARD_FLOAT): Define.
>         (GLIBC_DYNAMIC_LINKER_DEFAULT): Define.
>         (GLIBC_DYNAMIC_LINKER): Redefine to use the hard float path.
>
> diff --git a/gcc/config/arm/linux-eabi.h b/gcc/config/arm/linux-eabi.h
> index c0cfde3..142054f 100644
> --- a/gcc/config/arm/linux-eabi.h
> +++ b/gcc/config/arm/linux-eabi.h
> @@ -32,7 +32,8 @@
>    while (false)
>
>  /* We default to a soft-float ABI so that binaries can run on all
> -   target hardware.  */
> +   target hardware.  If you override this to use the hard-float ABI then
> +   change the setting of GLIBC_DYNAMIC_LINKER_DEFAULT as well.  */
>  #undef  TARGET_DEFAULT_FLOAT_ABI
>  #define TARGET_DEFAULT_FLOAT_ABI ARM_FLOAT_ABI_SOFT
>
> @@ -59,10 +60,25 @@
>  #undef  SUBTARGET_EXTRA_LINK_SPEC
>  #define SUBTARGET_EXTRA_LINK_SPEC " -m " TARGET_LINKER_EMULATION
>
> -/* Use ld-linux.so.3 so that it will be possible to run "classic"
> -   GNU/Linux binaries on an EABI system.  */
> +/* GNU/Linux on ARM currently supports three dynamic linkers:
> +   - ld-linux.so.2 - for the legacy ABI
> +   - ld-linux.so.3 - for the EABI-derived soft-float ABI
> +   - ld-linux-armhf.so.3 - for the EABI-derived hard-float ABI.
> +   All the dynamic linkers live in /lib.
> +   We default to soft-float, but this can be overridden by changing both
> +   GLIBC_DYNAMIC_LINKER_DEFAULT and TARGET_DEFAULT_FLOAT_ABI.  */
> +
>  #undef  GLIBC_DYNAMIC_LINKER
> -#define GLIBC_DYNAMIC_LINKER RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"
> +#define GLIBC_DYNAMIC_LINKER_SOFT_FLOAT \
> +  RUNTIME_ROOT_PREFIX "/lib/ld-linux.so.3"
> +#define GLIBC_DYNAMIC_LINKER_HARD_FLOAT \
> +  RUNTIME_ROOT_PREFIX "/lib/ld-linux-armhf.so.3"
> +#define GLIBC_DYNAMIC_LINKER_DEFAULT GLIBC_DYNAMIC_LINKER_SOFT_FLOAT
> +
> +#define GLIBC_DYNAMIC_LINKER \
> +   "%{mfloat-abi=hard:" GLIBC_DYNAMIC_LINKER_HARD_FLOAT "} \
> +    %{mfloat-abi=soft*:" GLIBC_DYNAMIC_LINKER_SOFT_FLOAT "} \
> +    %{!mfloat-abi=*:" GLIBC_DYNAMIC_LINKER_DEFAULT "}"
>
>  /* At this point, bpabi.h will have clobbered LINK_SPEC.  We want to
>     use the GNU/Linux version, not the generic BPABI version.  */