_mm512_roundscale_pd
Classification
AVX-512, Miscellaneous, CPUID Test: AVX512F
Header File
immintrin.h
Instruction
VRNDSCALEPD zmm, zmm, imm8
Synopsis
 _mm512_roundscale_pd(__m512d a, int imm8);
Description
Round packed double-precision (64-bit) floating-point elements in "a" to the number of fraction bits specified by "imm8", and store the results in "dst". [round_imm_note]
Operation
DEFINE RoundScaleFP64(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])
	IF IsInf(tmp[63:0])
		tmp[63:0] := src1[63:0]
	FI
	RETURN tmp[63:0]
}
FOR j := 0 to 7
	i := j*64
	dst[i+63:i] := RoundScaleFP64(a[i+63:i], imm8[7:0])
ENDFOR
dst[MAX:512] := 0