diff options
| author | Jussi Kivilinna <jussi.kivilinna@mbnet.fi> | 2012-06-09 18:25:46 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2012-06-14 10:07:23 +0800 |
| commit | d366db605c8c4a9878589bc4a87e55f6063184ac (patch) | |
| tree | a4984fee60973f52676ab9d9def30476ea0968bd /crypto/arc4.c | |
| parent | ce6dd368984068c8938e8d3fba8e292ef63cee97 (diff) | |
| download | lwn-d366db605c8c4a9878589bc4a87e55f6063184ac.tar.gz lwn-d366db605c8c4a9878589bc4a87e55f6063184ac.zip | |
crypto: arc4 - improve performance by using u32 for ctx and variables
This patch changes u8 in struct arc4_ctx and variables to u32 (as AMD seems
to have problem with u8 array). Below are tcrypt results of old 1-byte block
cipher versus ecb(arc4) with u8 and ecb(arc4) with u32.
tcrypt results, x86-64 (speed ratios: new-u32/old, new-u8/old):
u32 u8
AMD Phenom II : x3.6 x2.7
Intel Core 2 : x2.0 x1.9
tcrypt results, i386 (speed ratios: new-u32/old, new-u8/old):
u32 u8
Intel Atom N260 : x1.5 x1.4
Cc: Jon Oberheide <jon@oberheide.org>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/arc4.c')
| -rw-r--r-- | crypto/arc4.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/crypto/arc4.c b/crypto/arc4.c index 07913fc52c4e..5a772c3657d5 100644 --- a/crypto/arc4.c +++ b/crypto/arc4.c @@ -22,8 +22,8 @@ #define ARC4_BLOCK_SIZE 1 struct arc4_ctx { - u8 S[256]; - u8 x, y; + u32 S[256]; + u32 x, y; }; static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key, @@ -39,7 +39,7 @@ static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key, ctx->S[i] = i; for (i = 0; i < 256; i++) { - u8 a = ctx->S[i]; + u32 a = ctx->S[i]; j = (j + in_key[k] + a) & 0xff; ctx->S[i] = ctx->S[j]; ctx->S[j] = a; @@ -53,9 +53,9 @@ static int arc4_set_key(struct crypto_tfm *tfm, const u8 *in_key, static void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int len) { - u8 *const S = ctx->S; - u8 x, y, a, b; - u8 ty, ta, tb; + u32 *const S = ctx->S; + u32 x, y, a, b; + u32 ty, ta, tb; if (len == 0) return; |