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avutil/md5: fix misaligned reads 

This makes ubsan happy and also considerably increases performance on
big endian systems.

Tested on an IBM POWER7 3.55 GHz

Before:

2.24user 0.14system 0:02.39elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
2.26user 0.11system 0:02.38elapsed 99%CPU (0avgtext+0avgdata 2688maxresident)k
2.23user 0.15system 0:02.38elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
2.25user 0.12system 0:02.38elapsed 100%CPU (0avgtext+0avgdata 2624maxresident)k
2.20user 0.15system 0:02.36elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k

After:

1.86user 0.13system 0:02.00elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.89user 0.11system 0:02.01elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.85user 0.14system 0:02.00elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.84user 0.15system 0:01.99elapsed 99%CPU (0avgtext+0avgdata 2624maxresident)k
1.89user 0.13system 0:02.02elapsed 99%CPU (0avgtext+0avgdata 2688maxresident)k

Tested-by: Nicolas George <george@nsup.org>
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer 2017-03-03 00:25:54 -03:00
parent d8094a303b
commit e2b7ae4b19
1 changed files with 5 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
libavutil/md5.c
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@ -86,14 +86,14 @@ static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
\
if (i < 32) { \
if (i < 16) \
a += (d ^ (b & (c ^ d))) + X[ i & 15]; \
a += (d ^ (b & (c ^ d))) + AV_RL32(X+( i & 15));\
else \
a += ((d & b) | (~d & c)) + X[(1 + 5*i) & 15]; \
a += ((d & b) | (~d & c)) + AV_RL32(X+((1 + 5*i) & 15));\
} else { \
if (i < 48) \
a += (b ^ c ^ d) + X[(5 + 3*i) & 15]; \
a += (b ^ c ^ d) + AV_RL32(X+((5 + 3*i) & 15));\
else \
a += (c ^ (b | ~d)) + X[( 7*i) & 15]; \
a += (c ^ (b | ~d)) + AV_RL32(X+(( 7*i) & 15));\
} \
a = b + (a << t | a >> (32 - t)); \
} while (0)
@ -112,11 +112,6 @@ static void body(uint32_t ABCD[4], uint32_t *src, int nblocks)
X = src + n * 16;
#if HAVE_BIGENDIAN
for (i = 0; i < 16; i++)
X[i] = av_bswap32(X[i]);
#endif
#if CONFIG_SMALL
for (i = 0; i < 64; i++) {
CORE(i, a, b, c, d);
@ -173,7 +168,7 @@ void av_md5_update(AVMD5 *ctx, const uint8_t *src, int len)
}
end = src + (len & ~63);
if (HAVE_BIGENDIAN || (!HAVE_FAST_UNALIGNED && ((intptr_t)src & 3))) {
if (!HAVE_FAST_UNALIGNED && ((intptr_t)src & 3)) {
while (src < end) {
memcpy(ctx->block, src, 64);
body(ctx->ABCD, (uint32_t *) ctx->block, 1);