_mm_maskz_gf2p8affineinv_epi64_epi8

Function _mm_maskz_gf2p8affineinv_epi64_epi8 

1.89.0 · Source
pub fn _mm_maskz_gf2p8affineinv_epi64_epi8(
    k: __mmask16,
    x: __m128i,
    a: __m128i,
    const B: i32,
) -> __m128i
Available on (x86 or x86-64) and target feature gfni and target feature avx512bw and target feature avx512vl and x86 only.
Expand description

Performs an affine transformation on the inverted packed bytes in x. That is computes a*inv(x)+b over the Galois Field 2^8 for each packed byte with a being a 8x8 bit matrix and b being a constant 8-bit immediate value. The inverse of a byte is defined with respect to the reduction polynomial x^8+x^4+x^3+x+1. The inverse of 0 is 0. Each pack of 8 bytes in x is paired with the 64-bit word at the same position in a.

Uses the writemask in k - elements are zeroed in the result if the corresponding mask bit is not set. Otherwise the computation result is written into the result.

Intel’s documentation