| From 58d7d18b5268febb8b1391c6dffc8e2aaa751fcd Mon Sep 17 00:00:00 2001 |
| From: Herbert Xu <herbert@gondor.apana.org.au> |
| Date: Thu, 26 Jan 2012 15:03:16 +1100 |
| Subject: crypto: sha512 - Use binary and instead of modulus |
| |
| From: Herbert Xu <herbert@gondor.apana.org.au> |
| |
| commit 58d7d18b5268febb8b1391c6dffc8e2aaa751fcd upstream. |
| |
| The previous patch used the modulus operator over a power of 2 |
| unnecessarily which may produce suboptimal binary code. This |
| patch changes changes them to binary ands instead. |
| |
| Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| crypto/sha512_generic.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/crypto/sha512_generic.c |
| +++ b/crypto/sha512_generic.c |
| @@ -78,7 +78,7 @@ static inline void LOAD_OP(int I, u64 *W |
| |
| static inline void BLEND_OP(int I, u64 *W) |
| { |
| - W[I % 16] += s1(W[(I-2) % 16]) + W[(I-7) % 16] + s0(W[(I-15) % 16]); |
| + W[I & 15] += s1(W[(I-2) & 15]) + W[(I-7) & 15] + s0(W[(I-15) & 15]); |
| } |
| |
| static void |
| @@ -105,7 +105,7 @@ sha512_transform(u64 *state, const u8 *i |
| |
| #define SHA512_16_79(i, a, b, c, d, e, f, g, h) \ |
| BLEND_OP(i, W); \ |
| - t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[(i)%16]; \ |
| + t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[(i)&15]; \ |
| t2 = e0(a) + Maj(a, b, c); \ |
| d += t1; \ |
| h = t1 + t2 |