Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | [PATCH 8/9] powerpc: simplify csum_add(a, b) in case a or b is constant 0 | Date | Tue, 22 Sep 2015 16:34:34 +0200 (CEST) |
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Simplify csum_add(a, b) in case a or b is constant 0
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/include/asm/checksum.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h index 56deea8..f8a9704 100644 --- a/arch/powerpc/include/asm/checksum.h +++ b/arch/powerpc/include/asm/checksum.h @@ -119,7 +119,13 @@ static inline __wsum csum_add(__wsum csum, __wsum addend) { #ifdef __powerpc64__ u64 res = (__force u64)csum; +#endif + if (__builtin_constant_p(csum) && csum == 0) + return addend; + if (__builtin_constant_p(addend) && addend == 0) + return csum; +#ifdef __powerpc64__ res += (__force u64)addend; return (__force __wsum)((u32)res + (res >> 32)); #else -- 2.1.0
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