Visual Studio 2010

Microsoft Specific

Extracts the lower order floating point value from the parameter.

double _mm_cvtsd_f64( 
   __m128d a

[in] a

A 128-bit parameter that contains a floating point value in the lowest 64 bits.

The result can be expressed with the following equation:

r := a0




x86, x64

Header file <emmintrin.h>

r is the 64-bit floating point result. a0 is the lower 64 bits of parameter a. The upper 64 bits of a are ignored.

This intrinsic does not map to any specific machine instruction.

#include <stdio.h>
#include <emmintrin.h>

int main ()
    __m128d a;

    a.m128d_f64[0] = -200.5;

    double res = _mm_cvtsd_f64(a);

    printf_s("Original a: %I64f\n", a.m128d_f64[0]);
    printf_s("Result res: %I64f\n", res);

    return 0;
Original a: -200.500000
Result res: -200.500000

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