_mm_stream_sd

Artikkel
01/07/2022
2 minutter å lese

Microsoft Specific

Writes 64-bit data to a memory location without polluting the caches.

Syntax

void _mm_stream_sd(
   double * Dest,
   __m128d Source
);

Parameters

Dest
[out] A pointer to the location where the source data will be written.

Source
[in] A 128-bit value containing the double value to be written in its bottom 64 bits.

Return value

None.

Requirements

Intrinsic	Architecture
`_mm_stream_sd`	SSE4a

Header file <intrin.h>

Remarks

The intrinsic generates the movntsd instruction. To determine hardware support for this instruction, call the __cpuid intrinsic with InfoType=0x80000001 and check bit 6 of CPUInfo[2] (ECX). This bit is 1 if the hardware supports this instruction, and 0 otherwise.

If you run code that uses the _mm_stream_sd intrinsic on hardware that doesn't support the movntsd instruction, the results are unpredictable.

Example

// Compile this sample with: /EHsc
#include <iostream>
#include <intrin.h>
using namespace std;

int main()
{
    __m128d vals;
    double d[2];

    d[0] = -1.;
    d[1] = -2.;
    vals.m128d_f64[0] = 0.;
    vals.m128d_f64[1] = 1.;
    _mm_stream_sd(&d[1], vals);
    cout << "d[0] = " << d[0] << ", d[1] = " << d[1] << endl;
}

d[0] = -1, d[1] = 1

END Microsoft Specific