binary_cmov is slower than binary?

[ltang666]

I tested it found that for 128 size array binary_cmov is slower than binary on my x86_64, 8 CPU cores, and CPU MHz: 2194.916 machine, which showed binary_cmov was slower than binary.

compile： g++ -o b binary_search.cc --std=c++11 -O3

output：
time binary_cmov : 1.46695
time binary: 1.01361

my test program：

#include <iostream>
#include <chrono>
#include <ctime>

static int
binary_cmov (const int *arr, int n, int key) {
        int min = 0, max = n;
        while (min < max) {
                int middle = (min + max) >> 1;
                asm ("cmpl %3, %2\n\tcmovg %4, %0\n\tcmovle %5, %1"
                     : "+r" (min),
                       "+r" (max)
                     : "r" (key), "g" (arr [middle]),
                       "g" (middle + 1), "g" (middle));
        }
        return min;
}

static int
binary (const int *arr, int n, int key) {
        int min = 0, max = n;
        while (min < max) {
                int middle = (min + max) >> 1;
                if (key > arr [middle])
                        min = middle + 1;
                else
                        max = middle;
        }
        return min;
}

int main() {
    int size = 128;
    int arr[size];
    for (int i = 0; i < 128; ++i) {
        arr[i] = i;
    }

    const int loop = 100000;

    auto t_start = std::chrono::high_resolution_clock::now();
    for (int i = 0; i < loop; i++) {
        binary_cmov(arr, size, 40);
    }
    auto t_end = std::chrono::high_resolution_clock::now();
    std::cout << "time binary_cmov: " << std::chrono::duration<double, std::milli>(t_end-t_start).count() << '\n';

    auto t_start1 = std::chrono::high_resolution_clock::now();
    for (int i = 0; i < loop; i++) {
        binary(arr, size, 40);
    }
    auto t_end1 = std::chrono::high_resolution_clock::now();
    std::cout << "time binary: " << std::chrono::duration<double, std::milli>(t_end1-t_start1).count() << '\n';
}