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Updated: July 2008

Microsoft Specific

Generates the Convert with Truncation Scalar Single-Precision Floating-Point Value to Doubleword Integer (cvttss2si) instruction.

int _mm_cvtt_ss2si( 
   __m128 value 

[in] value

An __m128 structure containing two single-precision floating-point values.

An integer representing the result of the conversion.




x86 with SSE, x64

Header file <intrin.h>

The first element of the input structure value is converted to an integer and returned. Because the __m128 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_cvtt_ss2si.cpp
// processor: x86, x64
#include <intrin.h>
#include <stdio.h>

#pragma intrinsic(_mm_cvtt_ss2si)

int main()
    __m128 a;
    int b;

    float af[4] = { 101.25, 200.75,300.5, 400.5 };

    // Load a with the floating point values.
    // The values will be copied to the XMM registers.
    a = _mm_loadu_ps(af);

    // Extract the first element of a
    b = _mm_cvtt_ss2si(a);

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




July 2008

Revised availability from SSE2 to SSE.

Content bug fix.