_mm512_mask_cmul_round_pch
Classification
AVX-512, Arithmetic, CPUID Test: AVX512_FP16
Header File
Instruction
VFCMULCPH zmm {k}, zmm, zmm {er}
Synopsis
_mm512_mask_cmul_round_pch(__m512h src, __mmask16 k, __m512h a, __m512h b, const int rounding);
Description
Multiply packed complex numbers in "a" by the complex conjugates of packed complex numbers in "b", and store the results in "dst" using writemask "k" (elements are copied from "src" when the corresponding mask bit is not set). Each complex number is composed of two adjacent half-precision (16-bit) floating-point elements, which defines the complex number "complex = vec.fp16[0] + i * vec.fp16[1]", or the complex conjugate "conjugate = vec.fp16[0] - i * vec.fp16[1]".
[round_note]
Operation
FOR i := 0 to 15
IF k[i]
dst.fp16[2*i+0] := (a.fp16[2*i+0] * b.fp16[2*i+0]) + (a.fp16[2*i+1] * b.fp16[2*i+1])
dst.fp16[2*i+1] := (a.fp16[2*i+1] * b.fp16[2*i+0]) - (a.fp16[2*i+0] * b.fp16[2*i+1])
ELSE
dst.fp16[2*i+0] := src.fp16[2*i+0]
dst.fp16[2*i+1] := src.fp16[2*i+1]
FI
ENDFOR
dst[MAX:512] := 0