avx512-vaes: improved comment for pshufb based shift look-up table
@@ -109,9 +109,16 @@ rk7:
align 16
pshufb_shf_table:
- ;; use these values for shift registers with the pshufb instruction
- dq 0x8786858483828100, 0x8f8e8d8c8b8a8988
- dq 0x0706050403020100, 0x000e0d0c0b0a0908
+ ;; Values for shifting XMM registers with the pshufb instruction.
+ ;; Some usages of this table:
+ ;; - pshufb with pattern from [pshufb_shf_table + <index>]
+ ;; results with shifting <index> bytes from LSB to MSB
+ ;; - pshufb with pattern from [pshufb_shf_table pointer + 16 - <index]
+ ;; results in shifting XMM left by <index> bytes
+ ;; - pshufb with pattern from [pshufb_shf_table + <index>] xor'ed with 0x80 pattern
+ ;; results with shifting XMM right by <index> bytes
+ dq 0x8786858483828180, 0x8f8e8d8c8b8a8988
+ dq 0x0706050403020100, 0x0f0e0d0c0b0a0908
align 16
init_crc_value:
