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authorJussi Kivilinna <jussi.kivilinna@mbnet.fi>2012-06-09 18:25:46 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2012-06-14 10:07:23 +0800
commitd366db605c8c4a9878589bc4a87e55f6063184ac (patch)
treea4984fee60973f52676ab9d9def30476ea0968bd /crypto/arc4.c
parentce6dd368984068c8938e8d3fba8e292ef63cee97 (diff)
downloadlwn-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.c12
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;