Re: [PATCH v3 4/4] amdgpu/dc/calcs: Support clang option for stack alignment

[Harry Wentland <harry.wentland@amd.com>]

On 2018-02-08 03:53 PM, Matthias Kaehlcke wrote:
> calcs uses the compiler option -mpreferred-stack-boundary=4 to configure
> a stack alignment of 16 bytes. Clang uses the option -mstack-alignment
> instead, which expects as parameter the alignment in bytes, and not a
> power of two like -mpreferred-stack-boundary.
> 
> Probe for both compiler options and use the correct one, similar to
> what is done in arch/x86/Makefile.
> 
> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>

Series is
Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
> Changes in v3:
> - patch added
> 
> Note to self: if this patterns proliferates further we probably want to
> put the evaluation of the correct compiler flag in some common place.
> 
>  drivers/gpu/drm/amd/display/dc/calcs/Makefile | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/calcs/Makefile b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> index af0f452f3c9f..95f332ee3e7e 100644
> --- a/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> +++ b/drivers/gpu/drm/amd/display/dc/calcs/Makefile
> @@ -24,7 +24,13 @@
>  # It calculates Bandwidth and Watermarks values for HW programming
>  #
>  
> -calcs_ccflags := -mhard-float -msse -mpreferred-stack-boundary=4
> +ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
> +	cc_stack_align := -mpreferred-stack-boundary=4
> +else ifneq ($(call cc-option, -mstack-alignment=16),)
> +	cc_stack_align := -mstack-alignment=16
> +endif
> +
> +calcs_ccflags := -mhard-float -msse $(cc_stack_align)
>  
>  CFLAGS_dcn_calcs.o := $(calcs_ccflags)
>  CFLAGS_dcn_calc_auto.o := $(calcs_ccflags)
>