_mm_cvttsd_si64
Microsoft Specific
Emits the Streaming SIMD Extensions 2 (SSE2) instruction cvttsd2si. This instruction extracts a 64-bit floating point value and converts it to a signed 64-bit integer using truncation.
__int64 _mm_cvttsd_si64(
__m128d a
);
Parameters
- [in] a
A 128-bit parameter that contains a floating point value in the lowest 64 bits.
Return value
The result can be expressed with the following equation:
r := CVT(TRUNCATE(a0))
Requirements
Intrinsic |
Architecture |
|---|---|
_mm_cvttsd_si64 |
x64 |
Header file <emmintrin.h>
Remarks
r is the 64-bit signed integer result. a0 is the lower 64 bits of parameter a. The upper 64 bits of a are ignored.
Before you use this intrinsic, software must ensure that the processor supports the instruction.
Example
#include <stdio.h>
#include <emmintrin.h>
int main ()
{
__m128d a;
a.m128d_f64[0] = 3.5;
__int64 res = _mm_cvttsd_si64(a);
printf_s("Original a: %I64f\n", a.m128d_f64[0]);
printf_s("Result res: %I64d\n", res);
return 0;
}
Original a: 3.500000 Result res: 3