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Commit f334f74575cb0d9463d39caf4a43483cfc3dd542

Authored by Herbert Xu
Committed by Greg Kroah-Hartman
1 parent 23cfecf979

crypto: sha512 - Use binary and instead of modulus 

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>

Showing 1 changed file with 2 additions and 2 deletions Side-by-side Diff

crypto/sha512_generic.c
Diff comments   View file @ f334f74
... ... @@ -78,7 +78,7 @@
78 78  
79 79 static inline void BLEND_OP(int I, u64 *W)
80 80 {
81   - W[I % 16] += s1(W[(I-2) % 16]) + W[(I-7) % 16] + s0(W[(I-15) % 16]);
  81 + W[I & 15] += s1(W[(I-2) & 15]) + W[(I-7) & 15] + s0(W[(I-15) & 15]);
82 82 }
83 83  
84 84 static void
... ... @@ -105,7 +105,7 @@
105 105  
106 106 #define SHA512_16_79(i, a, b, c, d, e, f, g, h) \
107 107 BLEND_OP(i, W); \
108   - t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[(i)%16]; \
  108 + t1 = h + e1(e) + Ch(e, f, g) + sha512_K[i] + W[(i)&15]; \
109 109 t2 = e0(a) + Maj(a, b, c); \
110 110 d += t1; \
111 111 h = t1 + t2