_mm_cvt_pi2ps
Microsoft Specific
Generates the Convert Packed Doubleword Integers to Packed Single-Precision Floating-Point Values (cvtpi2ps) instruction, which converts the two packed 32-bit integers in b to single-precision floating-point values.
__m128 _mm_cvt_pi2ps(
__m128 a,
__m64 b
);
Parameters
[in] a
An __m128 structure containing four packed floating-point values.[in] b
An __m64 structure containing two packed 32-bit integers.
Return Value
An __m128 structure containing the result of the conversions as the first two elements; the third and fourth elements are copied from a.
Requirements
Intrinsic |
Architecture |
|---|---|
__mm_cvt_pi2ps |
x86 with SSE2 |
Header file <intrin.h>
Remarks
The results are stored in the first two elements of the __m128 structure returned; the other two elements of the return value are copied from the high quadword of a. The __m128 structure represents an XMM register and the __m64 structure represents an MMX register, so the instruction generated does not involve system memory.
This routine is only available as an intrinsic.
Example
// _mm_cvt_pi2ps.cpp
// processor: x86
#include <intrin.h>
#include <stdio.h>
#pragma intrinsic(_mm_cvt_pi2ps)
int main()
{
__m128 a;
__m64 b;
// Aligned because you are using _mm_load_ps to load these
// numbers into the XMM registers.
__declspec(align(16)) float af[4] = { 100.5, 200.5,300.5, 400.5 };
// Load a, which maps to the XMM registers, with the floating point
// values. _mm_load_ps requires a 16-byte aligned address.
a = _mm_load_ps(af);
// Load b with the two 32-bit signed integers.
b = _mm_set_pi32(32, 33);
// Copy the ints in a to the lower floating point slots of b.
a = _mm_cvt_pi2ps(a, b);
// Use the EMMS instruction to signal the transition from XMM
// registers to floating point registers (used to access the
// floating point values for printing to stdout).
_mm_empty();
// Print out the values in a.
printf_s("%lf %lf %lf %lf\n",
a.m128_f32[0], a.m128_f32[1],
a.m128_f32[2], a.m128_f32[3]);
}
33.000000 32.000000 300.500000 400.500000