The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at _mm_stream_ss.

Microsoft Specific**

Writes 32-bit data to a memory location without polluting the caches.


void _mm_stream_ss(  
   float * Dest,  
   __m128 Source  


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

[in] Source
A 128-bit number that contains the float value to be written in its bottom 32 bits..

Return Value



Intrinsic Architecture
_mm_stream_ss SSE4a

Header file <intrin.h>


This intrinsic generates the movntss instruction. To determine hardware support for this instruction, call the __cpuid intrinsic with InfoType=0x80000001and check bit 6 of CPUInfo[2] (ECX). This bit is 1 when the instruction is supported, and 0 otherwise.

If you run code that uses the _mm_stream_ss intrinsic on hardware that does not support the movntss instruction, the results are unpredictable.


// Compile this sample with: /EHsc  
#include <iostream>  
#include <intrin.h>  
using namespace std;  
int main()  
    __m128 vals;  
    float f[4];  
    f[0] = -1.;  
    f[1] = -2.;  
    f[2] = -3.;  
    f[3] = -4.;  
    vals.m128_f32[0] = 0.;  
    vals.m128_f32[1] = 1.;  
    vals.m128_f32[2] = 2.;  
    vals.m128_f32[3] = 3.;  
    _mm_stream_ss(&f[3], vals);  
    cout << "f[0] = " << f[0] << ", f[1] = " << f[1] << endl;  
    cout << "f[1] = " << f[1] << ", f[3] = " << f[3] << endl;  
f[0] = -1, f[1] = -2  
f[2] = -3, f[3] = 3  

END Microsoft Specific

Copyright 2007 by Advanced Micro Devices, Inc. All rights reserved. Reproduced with permission from Advanced Micro Devices, Inc.

See Also

Streaming SIMD Extensions that Support the Cache
Compiler Intrinsics