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xtea: invert branch and loop precedence

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Should slightly improve performance depending on the compiler used.
This commit is contained in:
Luca Barbato
2012-07-05 09:52:04 +02:00
parent 669bbedfa8
commit f6687bf5f8
1 changed files with 12 additions and 7 deletions
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19
libavutil/xtea.c
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@ -71,8 +71,8 @@ void av_xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
{ {
int i; int i;
while (count > 0) { if (decrypt) {
if (decrypt) { while (count > 0) {
xtea_crypt_ecb(ctx, dst, src, decrypt); xtea_crypt_ecb(ctx, dst, src, decrypt);
if (iv) { if (iv) {
@ -80,7 +80,13 @@ void av_xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
dst[i] = dst[i] ^ iv[i]; dst[i] = dst[i] ^ iv[i];
memcpy(iv, src, 8); memcpy(iv, src, 8);
} }
} else {
src += 8;
dst += 8;
count -= 8;
}
} else {
while (count > 0) {
if (iv) { if (iv) {
for (i = 0; i < 8; i++) for (i = 0; i < 8; i++)
dst[i] = src[i] ^ iv[i]; dst[i] = src[i] ^ iv[i];
@ -89,11 +95,10 @@ void av_xtea_crypt(AVXTEA *ctx, uint8_t *dst, const uint8_t *src, int count,
} else { } else {
xtea_crypt_ecb(ctx, dst, src, decrypt); xtea_crypt_ecb(ctx, dst, src, decrypt);
} }
src += 8;
dst += 8;
count -= 8;
} }
src += 8;
dst += 8;
count -= 8;
} }
} }