关于浮点数转换为整数的测试

#include <stdio.h>int main(void) {    float flt = 1.116533e24f;    printf("%e\n", flt);    printf("%ld\n", (long)flt); /* wrong */    printf("%u\n", *(unsigned long * const)&flt);   /* 将浮点数理解为整数 */    return 0;}

/* * 浮点数和整数强制类型转换的模拟测试 */#include <stdio.h>typedef int int32_t;typedef unsigned uint32_t;typedef unsigned char uint8_t;static int32_t float_to_int32(float flt) {    uint32_t ret;    uint8_t e;    ret = (*(uint32_t * const)&flt) & 0x007FFFFF; /* 取23位尾数 */    e = (uint8_t)((*(uint32_t * const)&flt) >> 23); /* 取8位阶码 */    if (ret == 0u) {        if (e == 0u)            return 0;        else if (e == 0xFF) {            puts("inf");            return 0xFFFFFFFF;        }    } else {        if (e == 0xFF) {            puts("NaN");            return 0;        }    }    ret |= 0x00800000; /* 写入隐藏位1 */    if (e >= 150u)        ret <<= e - 150u;    else        ret >>= 150u - e;    if ((*(uint32_t * const)&flt) >> 31)  /* 判断符号位 */        ret = -ret; /* 使用一元运算符 */    return (int32_t)ret;}static float int32_to_float(int32_t s32) {    uint32_t tmp;    uint8_t cnt;    if (s32 == 0)        return 0.0f;    if ((uint32_t)s32 >> 31)        tmp = -s32;    else        tmp = s32;    while (tmp) {        tmp >>= 1;        cnt++;    }    if ((uint32_t)s32 >> 31)        tmp = -s32;    else        tmp = s32;    if (cnt > 24u)        tmp >>= cnt - 24u;    else        tmp <<= 24u - cnt;    tmp &= 0xFF7FFFFF;    tmp |= (uint32_t)(cnt - 1u + 127u) << 23u;    if ((uint32_t)s32 >> 31) /* 写入符号位 */        tmp |= 0x80000000;    return *(float * const)&tmp;}int main(void) {    float f = -3451.987f; /* 不要超过int32_t的表示范围 */    int32_t s32 = -1234567; /* 不要超过float的7位精度 */    printf("%d\n", (int32_t)f);    printf("%d\n", float_to_int32(f));    printf("%f\n", (float)s32);    printf("%f\n", int32_to_float(s32));    return 0;}