_mm512_maskz_reduce_round_pd
Classification
AVX-512, Miscellaneous, CPUID Test: AVX512DQ
Header File
immintrin.h
Instruction
VREDUCEPD zmm {z}, zmm {sae}, imm8
Synopsis
 _mm512_maskz_reduce_round_pd(__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 zeromask "k" (elements are zeroed out 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] := 0
	FI
ENDFOR
dst[MAX:512] := 0