c - Is there memset() that accepts integers larger than char?

Question

Is there a version of memset() which sets a value that is larger than 1 byte (char)? For example, let's say we have a memset32() function, so using it we can do the following:

int32_t array[10];
memset32(array, 0xDEADBEEF, sizeof(array));

This will set the value 0xDEADBEEF in all the elements of array. Currently it seems to me this can only be done with a loop.

Specifically, I am interested in a 64 bit version of memset(). Know anything like that?

Answer 1

void memset64( void * dest, uint64_t value, uintptr_t size )
{
  uintptr_t i;
  for( i = 0; i < (size & (~7)); i+=8 )
  {
    memcpy( ((char*)dest) + i, &value, 8 );
  }  
  for( ; i < size; i++ )
  {
    ((char*)dest)[i] = ((char*)&value)[i&7];
  }  
}

(Explanation, as requested in the comments: when you assign to a pointer, the compiler assumes that the pointer is aligned to the type's natural alignment; for uint64_t, that is 8 bytes. memcpy() makes no such assumption. On some hardware unaligned accesses are impossible, so assignment is not a suitable solution unless you know unaligned accesses work on the hardware with small or no penalty, or know that they will never occur, or both. The compiler will replace small memcpy()s and memset()s with more suitable code so it is not as horrible is it looks; but if you do know enough to guarantee assignment will always work and your profiler tells you it is faster, you can replace the memcpy with an assignment. The second for() loop is present in case the amount of memory to be filled is not a multiple of 64 bits. If you know it always will be, you can simply drop that loop.)