SMHasher Sparse Test Failure

[SchrodingerZhu]

I am not an expert of SMHasher --- is this test suite stable? I found the issue when experimenting with the VAES patch, I remember it did pass all the tests but I re-run it several times and it gave a failure on Sparse now.

So I re-test it again with the master branch, I can still get the failure (BTW, I think the output is reasonable: I am not sure why SMHasher thought there was a failure) and the distribution is not the same as the results in the repo:

[schrodinger@schrodinger-superserver build]$ ./SMHasher --test Sparse ahash64
--- Testing ahash64 "ahash 64bit" GOOD

[[[ Keyset 'Sparse' Tests ]]]

Keyset 'Sparse' - 16-bit keys with up to 9 bits set - 50643 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected          0.3, actual      2 (6.70x) (2) !!!!!
Testing collisions (high 19-25 bits) - Worst is 19 bits: 2317/2368 (0.98x)
Testing collisions (low  32-bit) - Expected          0.3, actual      0 (0.00x)
Testing collisions (low  19-25 bits) - Worst is 25 bits: 45/38 (1.18x)
Testing distribution - Worst bias is the 13-bit window at bit 56 - 0.519%

Keyset 'Sparse' - 24-bit keys with up to 8 bits set - 1271626 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected        188.2, actual    176 (0.94x)
Testing collisions (high 24-35 bits) - Worst is 33 bits: 97/94 (1.03x)
Testing collisions (low  32-bit) - Expected        188.2, actual    190 (1.01x) (2)
Testing collisions (low  24-35 bits) - Worst is 34 bits: 52/47 (1.10x)
Testing distribution - Worst bias is the 17-bit window at bit 26 - 0.076%

Keyset 'Sparse' - 32-bit keys with up to 7 bits set - 4514873 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected       2372.2, actual   2418 (1.02x) (46)
Testing collisions (high 25-38 bits) - Worst is 37 bits: 89/74 (1.20x)
Testing collisions (low  32-bit) - Expected       2372.2, actual   2321 (0.98x)
Testing collisions (low  25-38 bits) - Worst is 38 bits: 47/37 (1.27x)
Testing distribution - Worst bias is the 19-bit window at bit 28 - 0.033%

Keyset 'Sparse' - 40-bit keys with up to 6 bits set - 4598479 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected       2460.8, actual   2496 (1.01x) (36)
Testing collisions (high 25-38 bits) - Worst is 36 bits: 166/153 (1.08x)
Testing collisions (low  32-bit) - Expected       2460.8, actual   2597 (1.06x) (137)
Testing collisions (low  25-38 bits) - Worst is 38 bits: 47/38 (1.22x)
Testing distribution - Worst bias is the 19-bit window at bit  2 - 0.061%

Keyset 'Sparse' - 48-bit keys with up to 6 bits set - 14196869 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected      23437.8, actual  23312 (0.99x) (-125)
Testing collisions (high 27-42 bits) - Worst is 41 bits: 48/45 (1.05x)
Testing collisions (low  32-bit) - Expected      23437.8, actual  23623 (1.01x) (186)
Testing collisions (low  27-42 bits) - Worst is 35 bits: 3028/2932 (1.03x)
Testing distribution - Worst bias is the 20-bit window at bit 25 - 0.021%

Keyset 'Sparse' - 56-bit keys with up to 5 bits set - 4216423 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected       2069.0, actual   2087 (1.01x) (19)
Testing collisions (high 25-38 bits) - Worst is 32 bits: 2087/2068 (1.01x)
Testing collisions (low  32-bit) - Expected       2069.0, actual   2171 (1.05x) (103)
Testing collisions (low  25-38 bits) - Worst is 36 bits: 149/129 (1.15x)
Testing distribution - Worst bias is the 19-bit window at bit 52 - 0.054%

Keyset 'Sparse' - 64-bit keys with up to 5 bits set - 8303633 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected       8021.7, actual   7959 (0.99x) (-62)
Testing collisions (high 26-40 bits) - Worst is 40 bits: 33/31 (1.05x)
Testing collisions (low  32-bit) - Expected       8021.7, actual   8031 (1.00x) (10)
Testing collisions (low  26-40 bits) - Worst is 40 bits: 36/31 (1.15x)
Testing distribution - Worst bias is the 20-bit window at bit 52 - 0.044%

Keyset 'Sparse' - 72-bit keys with up to 5 bits set - 15082603 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected      26451.8, actual  26517 (1.00x) (66)
Testing collisions (high 27-42 bits) - Worst is 38 bits: 429/413 (1.04x)
Testing collisions (low  32-bit) - Expected      26451.8, actual  26388 (1.00x) (-63)
Testing collisions (low  27-42 bits) - Worst is 42 bits: 30/25 (1.16x)
Testing distribution - Worst bias is the 20-bit window at bit 20 - 0.028%

Keyset 'Sparse' - 96-bit keys with up to 4 bits set - 3469497 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected       1401.0, actual   1394 (1.00x) (-6)
Testing collisions (high 25-38 bits) - Worst is 38 bits: 28/21 (1.28x)
Testing collisions (low  32-bit) - Expected       1401.0, actual   1402 (1.00x) (2)
Testing collisions (low  25-38 bits) - Worst is 38 bits: 23/21 (1.05x)
Testing distribution - Worst bias is the 19-bit window at bit 50 - 0.051%

Keyset 'Sparse' - 160-bit keys with up to 4 bits set - 26977161 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected      84546.1, actual  84600 (1.00x) (54)
Testing collisions (high 28-44 bits) - Worst is 38 bits: 1355/1323 (1.02x)
Testing collisions (low  32-bit) - Expected      84546.1, actual  84609 (1.00x) (63)
Testing collisions (low  28-44 bits) - Worst is 41 bits: 170/165 (1.03x)
Testing distribution - Worst bias is the 20-bit window at bit  1 - 0.011%

Keyset 'Sparse' - 256-bit keys with up to 3 bits set - 2796417 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected        910.2, actual    891 (0.98x)
Testing collisions (high 25-37 bits) - Worst is 37 bits: 34/28 (1.20x)
Testing collisions (low  32-bit) - Expected        910.2, actual    823 (0.90x)
Testing collisions (low  25-37 bits) - Worst is 37 bits: 36/28 (1.27x)
Testing distribution - Worst bias is the 19-bit window at bit 32 - 0.065%

Keyset 'Sparse' - 512-bit keys with up to 3 bits set - 22370049 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected      58155.4, actual  58078 (1.00x) (-77)
Testing collisions (high 28-43 bits) - Worst is 42 bits: 63/56 (1.11x)
Testing collisions (low  32-bit) - Expected      58155.4, actual  58143 (1.00x) (-12)
Testing collisions (low  28-43 bits) - Worst is 32 bits: 58143/58155 (1.00x)
Testing distribution - Worst bias is the 20-bit window at bit 51 - 0.016%

Keyset 'Sparse' - 1024-bit keys with up to 2 bits set - 524801 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected         32.1, actual     31 (0.97x)
Testing collisions (high 22-32 bits) - Worst is 23 bits: 16089/16079 (1.00x)
Testing collisions (low  32-bit) - Expected         32.1, actual     38 (1.19x) (6)
Testing collisions (low  22-32 bits) - Worst is 32 bits: 38/32 (1.19x)
Testing distribution - Worst bias is the 16-bit window at bit 14 - 0.147%

Keyset 'Sparse' - 2048-bit keys with up to 2 bits set - 2098177 keys
Testing collisions ( 64-bit) - Expected    0.0, actual      0 (0.00x)
Testing collisions (high 32-bit) - Expected        512.4, actual    516 (1.01x) (4)
Testing collisions (high 24-36 bits) - Worst is 36 bits: 37/32 (1.16x)
Testing collisions (low  32-bit) - Expected        512.4, actual    524 (1.02x) (12)
Testing collisions (low  24-36 bits) - Worst is 34 bits: 156/128 (1.22x)
Testing distribution - Worst bias is the 18-bit window at bit 47 - 0.080%

*********FAIL*********


Input vcode 0x00000001, Output vcode 0x00000001, Result vcode 0x00000001
Verification value is 0x00000001 - Testing took 33.405503 seconds

[tkaitchuck]

The test which is failing here is with inputs of 16 bits in length with 9 bits being 1s. (I am not sure why such short input would even be using the vectorized path). Never the less 32 or the 64bits are colliding. I suspect that the issue is one too few aes rounds is being run, and last input is only half defused

[tkaitchuck]

Resolved in 0.8.4