_mm256_reduce_pd
Classification
AVX-512, Miscellaneous, CPUID Test: AVX512DQ
Header File
Instruction
VREDUCEPD ymm, ymm, imm8
Synopsis
_mm256_reduce_pd(__m256d a, int imm8);
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". [round_imm_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 3
i := j*64
dst[i+63:i] := ReduceArgumentPD(a[i+63:i], imm8[7:0])
ENDFOR
dst[MAX:256] := 0