[PATCH] ARCv2: update memset() so it could be used without double load/stores

Vineet Gupta Vineet.Gupta1 at synopsys.com
Tue Oct 20 09:03:34 UTC 2015


On Monday 20 July 2015 07:42 PM, Alexey Brodkin wrote:
> From: Claudiu Zissulescu <claziss at synopsys.com>
> 
> Existing version of memset() relies on existence of 64-bit load/stores.
> While ARC HS38 may not have those instructions implemented in SoC.
> 
> Proposed implementation checks if "-mno-ll64" option was passed to gcc
> (for ARCv2 "-mll64" is set implicitly by default) by checking __LL64__
> definition and if it is not defined uses 32-bit load/stores.
> 
> Signed-off-by: Claudiu Zissulescu <claziss at synopsys.com>
> Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
> Cc: Vineet Gupta <vgupta at synopsys.com>


Ping ! Could this patch be applied please !

Thx,
-Vineet

> ---
>  libc/string/arc/arcv2/memset.S | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/libc/string/arc/arcv2/memset.S b/libc/string/arc/arcv2/memset.S
> index d076ad1..0918d37 100644
> --- a/libc/string/arc/arcv2/memset.S
> +++ b/libc/string/arc/arcv2/memset.S
> @@ -52,6 +52,7 @@ ENTRY(memset)
>  	lpnz	@.Lset64bytes
>  	;; LOOP START
>  	PREWRITE(r3, 64)	;Prefetch the next write location
> +#ifdef __LL64__
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
> @@ -60,16 +61,45 @@ ENTRY(memset)
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
> +#else
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +#endif
>  .Lset64bytes:
>  
>  	lsr.f	lp_count, r2, 5 ;Last remaining  max 124 bytes
>  	lpnz	.Lset32bytes
>  	;; LOOP START
>  	prefetchw [r3, 32]	;Prefetch the next write location
> +#ifdef __LL64__
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
>  	std.ab	r4, [r3, 8]
> +#else
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +	st.ab	r4, [r3, 4]
> +#endif
>  .Lset32bytes:
>  
>  	and.f	lp_count, r2, 0x1F ;Last remaining 31 bytes
> 



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