WebNov 6, 2024 · Investigate `gf2p8affineqb` for the shuffle step · Issue #117 · aklomp/base64 · GitHub This is a placeholder issue to make sure this gets noted somewhere. It looks like the gf2p8affineqb instruction can do arbitrary bit permutations on 8-bit characters. This could be very interesting to implement the bit shifts needed by t... WebDec 31, 2024 · Yeah, _mm256_movemask_epi8 is the key I think; use it to get the high bits (interleaved with garbage), then movemask_epi8( v<<15 ) to get the low bits. Packing those down to remove the garbage (or zeros) is trivial with BMI2 pext, but if you need this to be fast on Zen and Zen 2 (not just Intel), then that's harder.There's unfortunately no …
What are the AVX-512 Galois-field-related instructions for?
WebMay 29, 2024 · GF2P8AFFINEQB on the other hand is likely awesome. It takes each 8 bit value and ‘matrix multiplies’ it, in a carryless multiply sense, with a 8×8 bit matrix held in … WebDec 17, 2024 · Both require Ice Lake or Zen 4 or newer, and VGF2P8AFFINEQB is 5 cycle latency on port 0 or 1 on ICL (3c for on Zen 4, also 0.5c throughput), while VPMULTISHIFTQB is 3 cycle latency for port 5 on ICL. (Zen 4: 3c with 0.5c throughput). So the GFNI instruction is better, avoiding the VPAND. – Peter Cordes Dec 18, 2024 at 3:33 … mercury another name
LKML: Adrian Hunter: [PATCH 2/2] x86/insn: Add some more Intel ...
WebNov 25, 2024 · From: Adrian Hunter <> Subject [PATCH 2/2] x86/insn: Add some more Intel instructions to the opcode map: Date: Mon, 25 Nov 2024 14:50:44 +0200 Web*PATCH v2 01/10] x86emul: handle AVX512-FP16 insns encoded in 0f3a opcode map 2024-04-03 14:56 [PATCH v2 00/10] x86: support AVX512-FP16 Jan Beulich @ 2024-04-03 14:57 ` Jan Beulich 2024-04-03 14:57 ` [PATCH v2 02/10] x86emul: handle AVX512-FP16 Map5 arithmetic insns Jan Beulich ` (8 subsequent siblings) 9 siblings, 0 replies; 11 ... WebOct 2, 2024 · Galois Field New Instructions were intended for cryptography but the gf2p8affineqb can be used to do general purpose bit-shuffling within 8-bit elements of a simd vector for cases such as bit-reversal and bit-shifting. mercury anubis blue