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_mm_cvtepi16_epi64

Visual Studio 2010

Microsoft Specific

Emits the Streaming SIMD Extensions 4 (SSE4) instruction pmovsxwq. This instruction performs a conversion of signed integers from 16-bit to 64-bit.

Copy 
__m128i _mm_cvtepi16_epi64( 
   __m128i a
);
[in] a

A 128-bit parameter that contains two signed 16-bit integers in the lower 32 bits.

A 128-bit parameter that contains two 64-bit integers. These integers are sign-extended representations of the 16-bit integers that are supplied by a.

Intrinsic

Architecture

_mm_cvtepi16_epi64

x86, x64

Header file <smmintrin.h>

The result is defined as follows:

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r0 := a0
r1 := (a0 < 0) ? 0xffff : 0
r2 := (a0 < 0) ? 0xffff : 0
r3 := (a0 < 0) ? 0xffff : 0

r4 := a1
r5 := (a1 < 0) ? 0xffff : 0
r6 := (a1 < 0) ? 0xffff : 0
r7 := (a1 < 0) ? 0xffff : 0

r0-r7 and a0-a7 are the sequentially ordered 16-bit components of return value r and parameter a, respectively. r0 and a0 are the least significant 16 bits.

Before you use this intrinsic, software must ensure that the processor supports the instruction.

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#include <stdio.h>
#include <smmintrin.h>

int main ()
{
    __m128i a;

    a.m128i_i32[0] = 32767;
    a.m128i_i16[1] = -32768;

    __m128i res = _mm_cvtepi16_epi64(a);

    printf_s("Original lowest 16 bit integers:\n%i,\t%i\n\n",
        a.m128i_i16[1], a.m128i_i16[0]);

    printf_s("Resulting 64 bit integers:\n%I64i,\t%I64i\n",
        res.m128i_i64[1], res.m128i_i64[0]);

    return 0;
}

Original lowest 16 bit integers:
-32768, 32767

Resulting 64 bit integers:
-32768, 32767
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