_mm512_mask_reduce_round_pd
Classification
AVX-512, Miscellaneous, CPUID Test: AVX512DQ
Header File
Instruction
VREDUCEPD zmm {k}, zmm {sae}, imm8
Synopsis
_mm512_mask_reduce_round_pd(__m512d src, __mmask8 k, __m512d a, int imm8, int sae);
Description
Extract the reduced argument of packed double-precision (64-bit) floating-point elements in "a" by the number of bits specified by "imm8", and store the results in "dst" using writemask "k" (elements are copied from "src" when the corresponding mask bit is not set). [round_imm_note][sae_note]
Operation
DEFINE ReduceArgumentPD(src1[63:0], imm8[7:0]) {
m[63:0] := FP64(imm8[7:4]) // number of fraction bits after the binary point to be preserved
tmp[63:0] := POW(2.0, -m) * ROUND(POW(2.0, m) * src1[63:0], imm8[3:0])
tmp[63:0] := src1[63:0] - tmp[63:0]
IF IsInf(tmp[63:0])
tmp[63:0] := FP64(0.0)
FI
RETURN tmp[63:0]
}
FOR j := 0 to 7
i := j*64
IF k[j]
dst[i+63:i] := ReduceArgumentPD(a[i+63:i], imm8[7:0])
ELSE
dst[i+63:i] := src[i+63:i]
FI
ENDFOR
dst[MAX:512] := 0