[U-Boot] [PATCH v2] config.mk: use memoization in cc-option macro to speed up compilation

[Aneesh V]

On Friday 04 November 2011 06:15 PM, Daniel Schwierzeck wrote:
> Apply memoization to cc-option macro by caching the results of the
> gcc calls. This macro is called very often so using cached results
> leads to faster compilation times.

This one gives even better results compared to your
previous version.

Tested-by: Aneesh V <aneesh at ti.com>

br,
Aneesh


>
> Signed-off-by: Daniel Schwierzeck<daniel.schwierzeck at googlemail.com>
> ---
> Changes for v2:
>   - move cache file to $(obj)/include/generated
>   - reworked completely
>   - cache also non-working gcc options
>   - remove CACHE_CC_OPTIONS config switch and enable this optimization
>     by default
>
>   config.mk |   23 +++++++++++++++++++++--
>   1 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/config.mk b/config.mk
> index 918cffe..0da961a 100644
> --- a/config.mk
> +++ b/config.mk
> @@ -107,8 +107,27 @@ HOSTCFLAGS	+= -pedantic
>   # Option checker (courtesy linux kernel) to ensure
>   # only supported compiler options are used
>   #
> -cc-option = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
> -		>  /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
> +CC_OPTIONS_CACHE_FILE := $(OBJTREE)/include/generated/cc_options.mk
> +
> +$(if $(wildcard $(CC_OPTIONS_CACHE_FILE)),,\
> +	$(shell mkdir -p $(dir $(CC_OPTIONS_CACHE_FILE))))
> +
> +sinclude $(CC_OPTIONS_CACHE_FILE)
> +
> +_ccopt_sys = $(shell if $(CC) $(CFLAGS) $(1) -S -o /dev/null -xc /dev/null \
> +		>  /dev/null 2>&1; then \
> +		echo 'CC_OPTIONS += $(strip $1)'>>  $(CC_OPTIONS_CACHE_FILE); \
> +		echo "$(1)"; else \
> +		[ "x$(strip $2)" != "x" ]&&  \
> +			echo 'CC_OPTIONS_NOP += $(strip $2)'>>  $(CC_OPTIONS_CACHE_FILE); \
> +		echo "$(2)"; fi)
> +
> +_ccopt_cached = $(if $(filter $1,$(CC_OPTIONS)),$1,)
> +_ccopt_nop_cached = $(if $(filter $1,$(CC_OPTIONS_NOP)),$1,)
> +
> +cc-option = $(if $(call _ccopt_cached,$1),$1,\
> +		$(if $(call _ccopt_nop_cached,$2),$2,\
> +		$(call _ccopt_sys,$1,$2)))
>
>   #
>   # Include the make variables (CC, etc...)