Microsoft Specific
Emits the Streaming SIMD Extensions 4 (SSE4) instruction pcmpgtq. This instruction compares 64-bit integers that are passed in as 128-bit parameters.
__m128i _mm_cmpgt_epi64 (
     m128i a,
     m128i b
);
Parameters
| Parameter | Description | 
| [in] a | A 128-bit parameter that contains two 64-bit integers. | 
| [in] b | A 128-bit parameter that contains two 64-bit integers. | 
Return value
r0 := (a0 > b0) ? 0xffffffffffffffff : 0x0
r1 := (a1 > b1) ? 0xffffffffffffffff : 0x0
Requirements
| Intrinsic | Architecture | 
| _mm_cmpgt_epi64 | x86, x64 | 
Header file <nmmintrin.h>
Remarks
r0, a0, and b0 are the lower 64 bits of the return value and input parameters a and b.
r1, a1, and b1 are higher 64 bits of the return value and input parameters a and b.
Before using this intrinsic, software must ensure that the processor supports the instruction.
Example
#include <stdio.h>
#include <nmmintrin.h>
int main ()
{
    __m128i a, b;
    a.m128i_i64[1] = 0;
    a.m128i_i64[0] = -1;
    b.m128i_i64[1] = 0;
    b.m128i_i64[0] = -2;
    __m128i res = _mm_cmpgt_epi64(a, b);
    printf_s("Result res: 0x%016I64x 0x%016I64x\n",
                res.m128i_i64[1], res.m128i_i64[0]);
    return 0;
}
Result res: 0x0000000000000000 0xffffffffffffffff