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powerpc: simplify csum_add(a, b) in case a or b is constant 0 

Simplify csum_add(a, b) in case a or b is constant 0

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <oss@buserror.net>
This commit is contained in:
Christophe Leroy 2015-09-22 16:34:34 +02:00 committed by Scott Wood
parent f867d556dd
commit 5a8847c83c
1 changed files with 6 additions and 0 deletions
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6
arch/powerpc/include/asm/checksum.h
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@ -119,7 +119,13 @@ static inline __wsum csum_add(__wsum csum, __wsum addend)
{ {
#ifdef __powerpc64__ #ifdef __powerpc64__
u64 res = (__force u64)csum; 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; res += (__force u64)addend;
return (__force __wsum)((u32)res + (res >> 32)); return (__force __wsum)((u32)res + (res >> 32));
#else #else