用C语言在Arm RVCT编译器上将double转换为int

Question

I need to get last four bytes out of a double variable .The platform is Arm and compiler is RVCT.Programming language used is C.What is the safest way.

Thanks

Answer 1

double dval = 3.14159;

// as an int
uint32_t ival = *(uint32_t*)&dval;

// as bytes
uint8_t *all_bytes = (uint8_t*)&dval;

uint8_t *last_four_bytes = all_bytes + 4;

Answer 2

int lastFour = *(((char*) &origDouble) + sizeof(double) - 4)