[U-Boot] [PATCH] powerpc/mpc85xx:Add GCC flag -fno-delete-null-pointer-checks

[York Sun <yorksun@freescale.com>]

Scott,

Please comment on this patch.

York

On 05/06/2015 11:07 PM, Prabhakar Kushwaha wrote:
>  -fdelete-null-pointer-checks flag controls global dataflow analyses and
>  eliminate useless checks for null pointers; It assume that if a pointer is
>  checked after it has already been dereferenced, it cannot be null.
>  This flag is enabled by default.
> 
>  gcc v4.9 has more optimizations added to this option. Hence it is very
>  aggressive with GCC v4.9 series. Add -fno-delete-null-pointer-checks to
>  disable the optimization
> 
> Signed-off-by: Rohit Dharmakan <rohitarulraj@freescale.com>
> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
> ---
>  arch/powerpc/cpu/mpc85xx/config.mk | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/cpu/mpc85xx/config.mk b/arch/powerpc/cpu/mpc85xx/config.mk
> index 72c964c..2aedd24 100644
> --- a/arch/powerpc/cpu/mpc85xx/config.mk
> +++ b/arch/powerpc/cpu/mpc85xx/config.mk
> @@ -5,7 +5,8 @@
>  # SPDX-License-Identifier:	GPL-2.0+
>  #
>  
> -PLATFORM_CPPFLAGS += -Wa,-me500 -msoft-float -mno-string
> +PLATFORM_CPPFLAGS += -Wa,-me500 -msoft-float -mno-string \
> +					-fno-delete-null-pointer-checks
>  
>  # -mspe=yes is needed to have -mno-spe accepted by a buggy GCC;
>  # see "[PATCH,rs6000] make -mno-spe work as expected" on
>