We recently learned our Simon and Speck implementation was wrong. The removal will stop harm until we can loop back and fix the issue.
The issue is, the paper, the test vectors and the ref-impl do not align. Each produces slightly different result. We followed the test vectors but they turned out to be wrong for the ciphers.
We have one kernel test vector but we don't have a working implementation to observe it to fix our implementation. Ugh...
This also fixes the SPECK64 bug where CTR mode self tests fail. It was an odd failure because it only affected 64-bit SPECK. SIMON was fine and it used nearly the same code. We tracked it down through trial and error to the table based rotates.
It looks like the delay was due to some GCC 7 issue. We had to disable parallel blocks on Aarch64 with GCC 7. We may be running out of registers and that could be causing problems. It looks like GCC uses up to v30.
For Simon-64 and Speck-64 this means we are effectively using 12x-4x-1x. We are mostly at the threshold for IA-32 and parallelization. At any time 10 to 13 XMM registers are being used.
Prefer movsd by way of _mm_load_sd and _mm_store_sd.
Fix "error C3861: _mm_cvtsi128_si64x identifier not found".
The folding of statements helps GCC elimate some of the intermediate stores it was performing. The elimination saved about 1.0 cpb. SIMON-128 is now running around 10 cpb, but it is still off the Simon and Speck team's numbers of 3.5 cpb
Louis Wingers and Bryan Weeks from the Simon and Speck team offered the suggestion. The change save 0.7 cpb for Speck, and 5 cpb for Simon on x86_64.
Speck is now running very close to the Team's time sor SSE4. Simon is still off, but we know the root cause. For Simon, the Team used a fast bit-sliced implementation
Fabrice Fontaine
Jeffrey Walton