search for: extrv

Displaying 2 results from an estimated 2 matches for "extrv".

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2018 Jul 02
2
Rotates, once again
...t distances must be literal constants. EXTR with both source registers equal disassembles as ROR and is often special-cased in implementations. (EXTR with source 1 != source 2 often has an extra cycle of latency). There is RORV which is right rotate by a variable (register) amount; there is no EXTRV. - NVPTX has SHF (https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#logic-and-shift-instructions-shf) with both left/right shift variants and with both "clamp" (clamps shift count at 32) and "wrap" (shift count taken mod 32) modes. - GCN has v_alignbit_b32 w...
2018 Jul 02
2
Rotates, once again
1. I'm not sure what you mean by "full vector" here - using the same shift distance for all lanes (as opposed to per-lane distances), or doing a treat-the-vector-as-bag-of-bits shift that doesn't have any internal lane boundaries? If the latter, that doesn't really help you much with implementing a per-lane rotate. I think the most useful generalization of a vector