好丢人啊改改编译参数手工汇编优化的代码就被甩出好多改天认真研究一下编译器的写法好像我的写法有点问题 - C语言论坛

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好丢人啊改改编译参数手工汇编优化的代码就被甩出好多改天认真研究一下编译器的写法好像我的写法有点问题

先上结论

C Elapsed 2218 ms
C(with complex) Elapsed 2125 ms
ASM Elapsed 2156 ms

程序欢迎测试

c+c_99+asm.zip (17.52 KB)

两个C代码依次是

程序代码：

// 代码来自 <span style="color: #008000; text-decoration: underline;">https://bbs.bccn.net/thread-365456-1-1.html[/color]
// gcc -Wall -O3 fenxing.c -msse3 -march=core2 -mfpmath=sse -ffast-math -o c.exe

#include <stdio.h>
#include <time.h>
#include <stdlib.h>

#define BAILOUT 16
#define MAX_ITERATIONS 1000

#define SIZE (1024*1024*1)

char *pnow = NULL;

inline int put(char ch)
{
    *pnow++ = ch;
    return 0;
}

inline int mandelbrot(double x, double y)
{
    double cr = y - 0.5;
    double ci = x;
    double zi = 0.0;
    double zr = 0.0;
    int i = 0;

    while(1)
    {
        i++;
        double temp = zr * zi;
        double zr2 = zr * zr;
        double zi2 = zi * zi;
        zr = zr2 - zi2 + cr;
        zi = temp + temp + ci;
        if (zi2 + zr2 > BAILOUT)
            return i;
        if (i > MAX_ITERATIONS)
            return 0;
    }
}

int main()
{
    long t1 = 0, t2 = 0;
    char *pbuf = calloc(1, SIZE);
    pnow = pbuf;

    t1 = clock();

    int x,y;
    for (y = -399; y < 399; y++) {
        put('\n');
        for (x = -399; x < 399; x++) {
            int i = mandelbrot(x/400.0, y/400.0);
            if (i == 0)
                put('*');
            else
                put(' ');
        }
    }
    put('\n');

    t2 = clock();
    printf("C Elapsed %ld ms\n", (t2 - t1));
    printf("%s\n", pbuf);
    free(pbuf);

    return 0;
}

程序代码：

// 代码来自 <span style="color: #008000; text-decoration: underline;">https://bbs.bccn.net/thread-365456-1-1.html[/color]
// gcc -Wall fenxing_C99.c -O3 -msse3 -march=core2 -mfpmath=sse -ffast-math -o c_c99.exe

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <complex.h>

#define BAILOUT 16
#define MAX_ITERATIONS 1000

#define SIZE (1024*1024*10)

char *pnow = NULL;

inline void my_put(char ch)
{
    *pnow++ = ch;
}

inline int mandelbrot(double x, double y)
{
    double _Complex c = y - 0.5 + x * I;
    double _Complex z = 0.0;
    int i = 0;

    while(1)
    {
        i++;
        if (creal(z)*creal(z)+cimag(z)*cimag(z) > BAILOUT)
            return i;
        if (i > MAX_ITERATIONS)
            return 0;
        z = z * z + c;
    }
}

int main()
{
    long t1 = 0, t2 = 0;
    char *pbuf = calloc(1, SIZE);
    pnow = pbuf;

    t1 = clock();
    int x,y;
    for (y = -399; y < 399; y++) {
        my_put('\n');
        for (x = -399; x < 399; x++) {
            if (mandelbrot(x/400.0, y/400.0) == 0)
                my_put('*');
            else
                my_put(' ');
        }
    }
    my_put('\n');

    t2 = clock();
    printf("C(with complex) Elapsed %ld ms\n", (t2 - t1));
    printf("%s\n", pbuf);
    free(pbuf);

    return 0;
}

一个收获是写直接的代码这里采用C里面带的复数的特性就比自己实现的复数运算效率要高因为这时候优化的程序更容易理解编程者的意思还有一个收获是我的SSE水平有待提高啊呵呵

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