[Buildroot] [PATCH v2] xtensa: add config option to enable longcalls option

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Dear Chris Zankel,

On Mon, 3 Dec 2012 00:58:46 -0800, Chris Zankel wrote:
> The longcalls option allows calls across a greater range of addresses.
> 
> This option should be used when call targets can potentially be
> out of range. It may degrade both code size and performance, but
> the linker can generally optimize away the unnecessary overhead
> when a call ends up within range.
> 
> This option is enabled by default.
> 
> Signed-off-by: Chris Zankel <chris@zankel.net>
> ---
>  arch/Config.in.xtensa |   17 +++++++++++++++++
>  package/Makefile.in   |    6 ++++++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/arch/Config.in.xtensa b/arch/Config.in.xtensa
> index 60c03f5..a979108 100644
> --- a/arch/Config.in.xtensa
> +++ b/arch/Config.in.xtensa
> @@ -35,3 +35,20 @@ config BR2_XTENSA_OVERLAY_DIR
>  
>  config BR2_ARCH
>  	default "xtensa"	if BR2_xtensa
> +
> +menu "Target build options"
> +
> +config BR2_XTENSA_LONGCALLS
> +	bool "Enable longcalls option"
> +	default y
> +	help
> +	  Enable or disable transformation of call instructions to allow
> +	  calls across a greater range of addresses.
> +	  This option should be used when call targets can potentially be
> +	  out of range. It may degrade both code size and performance, but
> +	  the linker can generally optimize away the unnecessary overhead
> +	  when a call ends up within range. 
> +
> +	  Should be enabled by default.
> +
> +endmenu

Do we really want that as a configurable option? Isn't it possible
instead to always generate longcalls, or to fix this on a per-package
basis, when needed?

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com