[PATCH 2/7] block-sha1: try to use rol/ror appropriately
- From
Linus Torvalds <torvalds@linux-foundation.org>
- Date
- Aug 6, 2009, 15:16 UTC
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- <alpine.LFD.2.01.0908060815430.3390@localhost.localdomain>
- In-Reply-To
- <alpine.LFD.2.01.0908060814050.3390@localhost.localdomain>
From: Linus Torvalds <torvalds@linux-foundation.org> Date: Wed, 5 Aug 2009 19:42:15 -0700 Subject: [PATCH 2/7] block-sha1: try to use rol/ror appropriately
Use the one with the smaller constant. It _can_ generate slightly smaller code (a constant of 1 is special), but perhaps more importantly it's possibly faster on any uarch that does a rotate with a loop.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> ---
Ok, this is the hackiest of the bunch. I considered dropping it. But I do suspect we want something like this, even if we might end up massaging the asm for different compilers etc.
block-sha1/sha1.c | 32 ++++++++++++++++++++++---------- 1 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/block-sha1/sha1.c b/block-sha1/sha1.c index eef32f7..a45a3de 100644 --- a/block-sha1/sha1.c +++ b/block-sha1/sha1.c @@ -80,7 +80,19 @@ void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx) ((unsigned int *)hashout)[i] = htonl(ctx->H[i]); } -#define SHA_ROT(X,n) (((X) << (n)) | ((X) >> (32-(n)))) +#if defined(__i386__) || defined(__x86_64__) + +#define SHA_ASM(op, x, n) ({ unsigned int __res; asm(op " %1,%0":"=r" (__res):"i" (n), "0" (x)); __res; }) +#define SHA_ROL(x,n) SHA_ASM("rol", x, n) +#define SHA_ROR(x,n) SHA_ASM("ror", x, n) + +#else + +#define SHA_ROT(X,n) (((X) << (l)) | ((X) >> (r))) +#define SHA_ROL(X,n) SHA_ROT(X,n,32-(n)) +#define SHA_ROR(X,n) SHA_ROT(X,32-(n),n) + +#endif static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) { @@ -93,7 +105,7 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) /* Unroll it? */ for (t = 16; t <= 79; t++) - W[t] = SHA_ROT(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1); + 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]; @@ -102,8 +114,8 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) E = ctx->H[4]; #define T_0_19(t) \ - TEMP = SHA_ROT(A,5) + (((C^D)&B)^D) + E + W[t] + 0x5a827999; \ - E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP; + 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); @@ -111,8 +123,8 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) T_0_19(15); T_0_19(16); T_0_19(17); T_0_19(18); T_0_19(19); #define T_20_39(t) \ - TEMP = SHA_ROT(A,5) + (B^C^D) + E + W[t] + 0x6ed9eba1; \ - E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP; + TEMP = SHA_ROL(A,5) + (B^C^D) + E + W[t] + 0x6ed9eba1; \ + E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; T_20_39(20); T_20_39(21); T_20_39(22); T_20_39(23); T_20_39(24); T_20_39(25); T_20_39(26); T_20_39(27); T_20_39(28); T_20_39(29); @@ -120,8 +132,8 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) T_20_39(35); T_20_39(36); T_20_39(37); T_20_39(38); T_20_39(39); #define T_40_59(t) \ - TEMP = SHA_ROT(A,5) + ((B&C)|(D&(B|C))) + E + W[t] + 0x8f1bbcdc; \ - E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP; + TEMP = SHA_ROL(A,5) + ((B&C)|(D&(B|C))) + E + W[t] + 0x8f1bbcdc; \ + E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; T_40_59(40); T_40_59(41); T_40_59(42); T_40_59(43); T_40_59(44); T_40_59(45); T_40_59(46); T_40_59(47); T_40_59(48); T_40_59(49); @@ -129,8 +141,8 @@ static void blk_SHA1Block(blk_SHA_CTX *ctx, const unsigned int *data) T_40_59(55); T_40_59(56); T_40_59(57); T_40_59(58); T_40_59(59); #define T_60_79(t) \ - TEMP = SHA_ROT(A,5) + (B^C^D) + E + W[t] + 0xca62c1d6; \ - E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP; + TEMP = SHA_ROL(A,5) + (B^C^D) + E + W[t] + 0xca62c1d6; \ + E = D; D = C; C = SHA_ROR(B, 2); B = A; A = TEMP; T_60_79(60); T_60_79(61); T_60_79(62); T_60_79(63); T_60_79(64); T_60_79(65); T_60_79(66); T_60_79(67); T_60_79(68); T_60_79(69);
-- 1.6.4.31.g154b2.dirty