summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/asm
diff options
context:
space:
mode:
authorChristophe Leroy <christophe.leroy@c-s.fr>2015-09-22 16:34:34 +0200
committerScott Wood <oss@buserror.net>2016-03-05 06:04:00 +0100
commit5a8847c83ce6072d6fdf0d15d9aa060c0b83537f (patch)
treee45ad68b2205e70108faa4ece40f35a315ea973b /arch/powerpc/include/asm
parentpowerpc32: optimise csum_partial() loop (diff)
downloadlinux-5a8847c83ce6072d6fdf0d15d9aa060c0b83537f.tar.xz
linux-5a8847c83ce6072d6fdf0d15d9aa060c0b83537f.zip
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>
Diffstat (limited to 'arch/powerpc/include/asm')
-rw-r--r--arch/powerpc/include/asm/checksum.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/checksum.h b/arch/powerpc/include/asm/checksum.h
index 1778f75bf769..74cd8d82628a 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