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authorDenys Vlasenko2014-07-30 14:18:57 +0200
committerDenys Vlasenko2014-07-30 14:18:57 +0200
commit4ff933c0e7895bd1ac1fe9793117f4d69de35514 (patch)
tree9d65877c7d29614b335b34164afb4eee57b3f4f7 /libbb
parent6c6d37ee4526f77fe07e46f05b0378ce43421e84 (diff)
downloadbusybox-4ff933c0e7895bd1ac1fe9793117f4d69de35514.zip
busybox-4ff933c0e7895bd1ac1fe9793117f4d69de35514.tar.gz
sha3: code shrink (and speedup for SHA3_SMALL=0)
function old new delta sha3_process_block72 1454 1359 -95 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'libbb')
-rw-r--r--libbb/hash_md5_sha.c82
1 files changed, 66 insertions, 16 deletions
diff --git a/libbb/hash_md5_sha.c b/libbb/hash_md5_sha.c
index dff583a..4cef2ab 100644
--- a/libbb/hash_md5_sha.c
+++ b/libbb/hash_md5_sha.c
@@ -1141,22 +1141,30 @@ static void sha3_process_block72(uint64_t *state)
#undef RhoPi
}
/* Chi */
- for (x = 0; x <= 20; x += 5) {
- /*
- * Can write this in terms of uint32 too,
- * but why? compiler does it automatically.
- */
- uint64_t BC0, BC1, BC2, BC3, BC4;
- BC0 = state[x + 0];
- BC1 = state[x + 1];
- BC2 = state[x + 2];
- state[x + 0] = BC0 ^ ((~BC1) & BC2);
- BC3 = state[x + 3];
- state[x + 1] = BC1 ^ ((~BC2) & BC3);
- BC4 = state[x + 4];
- state[x + 2] = BC2 ^ ((~BC3) & BC4);
- state[x + 3] = BC3 ^ ((~BC4) & BC0);
- state[x + 4] = BC4 ^ ((~BC0) & BC1);
+ for (x = 0; x <= 40;) {
+ uint32_t BC0, BC1, BC2, BC3, BC4;
+ BC0 = s32[x + 0*2];
+ BC1 = s32[x + 1*2];
+ BC2 = s32[x + 2*2];
+ s32[x + 0*2] = BC0 ^ ((~BC1) & BC2);
+ BC3 = s32[x + 3*2];
+ s32[x + 1*2] = BC1 ^ ((~BC2) & BC3);
+ BC4 = s32[x + 4*2];
+ s32[x + 2*2] = BC2 ^ ((~BC3) & BC4);
+ s32[x + 3*2] = BC3 ^ ((~BC4) & BC0);
+ s32[x + 4*2] = BC4 ^ ((~BC0) & BC1);
+ x++;
+ BC0 = s32[x + 0*2];
+ BC1 = s32[x + 1*2];
+ BC2 = s32[x + 2*2];
+ s32[x + 0*2] = BC0 ^ ((~BC1) & BC2);
+ BC3 = s32[x + 3*2];
+ s32[x + 1*2] = BC1 ^ ((~BC2) & BC3);
+ BC4 = s32[x + 4*2];
+ s32[x + 2*2] = BC2 ^ ((~BC3) & BC4);
+ s32[x + 3*2] = BC3 ^ ((~BC4) & BC0);
+ s32[x + 4*2] = BC4 ^ ((~BC0) & BC1);
+ x += 9;
}
/* Iota */
s32[0] ^= IOTA_CONST_0bits & 1;
@@ -1275,6 +1283,7 @@ static void sha3_process_block72(uint64_t *state)
#undef RhoPi_twice
}
/* Chi */
+#if LONG_MAX > 0x7fffffff
for (x = 0; x <= 20; x += 5) {
uint64_t BC0, BC1, BC2, BC3, BC4;
BC0 = state[x + 0];
@@ -1288,6 +1297,47 @@ static void sha3_process_block72(uint64_t *state)
state[x + 3] = BC3 ^ ((~BC4) & BC0);
state[x + 4] = BC4 ^ ((~BC0) & BC1);
}
+#else
+ /* Reduced register pressure version
+ * for register-starved 32-bit arches
+ * (i386: -95 bytes, and it is _faster_)
+ */
+ for (x = 0; x <= 40;) {
+ uint32_t BC0, BC1, BC2, BC3, BC4;
+ uint32_t *const s32 = (uint32_t*)state;
+# if SHA3_SMALL
+ do_half:
+#endif
+ BC0 = s32[x + 0*2];
+ BC1 = s32[x + 1*2];
+ BC2 = s32[x + 2*2];
+ s32[x + 0*2] = BC0 ^ ((~BC1) & BC2);
+ BC3 = s32[x + 3*2];
+ s32[x + 1*2] = BC1 ^ ((~BC2) & BC3);
+ BC4 = s32[x + 4*2];
+ s32[x + 2*2] = BC2 ^ ((~BC3) & BC4);
+ s32[x + 3*2] = BC3 ^ ((~BC4) & BC0);
+ s32[x + 4*2] = BC4 ^ ((~BC0) & BC1);
+ x++;
+# if SHA3_SMALL
+ if (x & 1)
+ goto do_half;
+ x += 8;
+# else
+ BC0 = s32[x + 0*2];
+ BC1 = s32[x + 1*2];
+ BC2 = s32[x + 2*2];
+ s32[x + 0*2] = BC0 ^ ((~BC1) & BC2);
+ BC3 = s32[x + 3*2];
+ s32[x + 1*2] = BC1 ^ ((~BC2) & BC3);
+ BC4 = s32[x + 4*2];
+ s32[x + 2*2] = BC2 ^ ((~BC3) & BC4);
+ s32[x + 3*2] = BC3 ^ ((~BC4) & BC0);
+ s32[x + 4*2] = BC4 ^ ((~BC0) & BC1);
+ x += 9;
+# endif
+ }
+#endif
/* Iota */
state[0] ^= IOTA_CONST[round]
| (uint32_t)((IOTA_CONST_bit31 << round) & 0x80000000)