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Microsoft Specific

Generates the x64 extended version of the Convert with Truncation Scalar Double-Precision Floating-Point Value to 64-Bit Integer (cvttsd2si) instruction, which takes the first double in the input structure of packed doubles, converts it to a 64-bit integer, and returns the result.

__int64 _mm_cvttsd_si64x( 
   __m128d value 


[in] value

An __m128d structure containing double-precision floating-point values.

The result of the conversion of the first double in the input to a 64-bit integer.

Intrinsic Architecture



Header file <intrin.h>

The function differs from _mm_cvtsd_si64x only in that inexact conversions are truncated toward zero. If the result overflows, the value 0x8000000000000000 (-9223372036854775808) is returned. Because the __m128d structure represents an XMM register, the instruction generated moves data from an XMM register into system memory.

This routine is only available as an intrinsic.

// _mm_cvttsd_si64x.cpp
// processor: x64
#include <intrin.h>
#include <stdio.h>

#pragma intrinsic(_mm_cvttsd_si64x)

int main()
    __m128d d;
    __int64 b;

    double adbl[2] = { 101.5, 200.5 };

    // store the double values into d
    // (moves data into the XMM registers)
    d = _mm_loadu_pd (adbl);

    // Extract the first element of d
    b = _mm_cvttsd_si64x(d);

    printf_s("%I64d\n", b );