kernel
/
git
mirror of https://git.kernel.org/pub/scm/git/git.git
1
0
Fork 0
Code Releases Activity

block-sha1: make the 'ntohl()' part of the first SHA1 loop 

This helps a teeny bit.  But what I -really- want to do is to avoid the
whole 80-array loop, and do the xor updates as I go along..

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
maint
Linus Torvalds 2009-08-05 20:28:07 -07:00 committed by Junio C Hamano
parent fd536d3439
commit 139e3456ec
1 changed files with 16 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
block-sha1/sha1.c
View File

@ -100,27 +100,31 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data)
unsigned int A,B,C,D,E,TEMP;
unsigned int W[80];

for (t = 0; t < 16; t++)
W[t] = htonl(data[t]);

/* Unroll it? */
for (t = 16; t <= 79; t++)
W[t] = SHA_ROL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

A = ctx->H[0];
B = ctx->H[1];
C = ctx->H[2];
D = ctx->H[3];
E = ctx->H[4];

#define T_0_19(t) \
#define T_0_15(t) \
TEMP = htonl(data[t]); W[t] = TEMP; \
TEMP += SHA_ROL(A,5) + (((C^D)&B)^D) + E + 0x5a827999; \
E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; \

T_0_15( 0); T_0_15( 1); T_0_15( 2); T_0_15( 3); T_0_15( 4);
T_0_15( 5); T_0_15( 6); T_0_15( 7); T_0_15( 8); T_0_15( 9);
T_0_15(10); T_0_15(11); T_0_15(12); T_0_15(13); T_0_15(14);
T_0_15(15);

/* Unroll it? */
for (t = 16; t <= 79; t++)
W[t] = SHA_ROL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

#define T_16_19(t) \
TEMP = SHA_ROL(A,5) + (((C^D)&B)^D) + E + W[t] + 0x5a827999; \
E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP;

T_0_19( 0); T_0_19( 1); T_0_19( 2); T_0_19( 3); T_0_19( 4);
T_0_19( 5); T_0_19( 6); T_0_19( 7); T_0_19( 8); T_0_19( 9);
T_0_19(10); T_0_19(11); T_0_19(12); T_0_19(13); T_0_19(14);
T_0_19(15); T_0_19(16); T_0_19(17); T_0_19(18); T_0_19(19);
T_16_19(16); T_16_19(17); T_16_19(18); T_16_19(19);

#define T_20_39(t) \
TEMP = SHA_ROL(A,5) + (B^C^D) + E + W[t] + 0x6ed9eba1; \