function S64
clamp_top_s64(S64 val, S64 max){
  if(val>max)return max;
  return val;
}

function SizeU
clamp_top_sizeu(SizeU val, SizeU max){
  if(val>max)return max;
  return val;
}

function SizeU
get_align_offset(SizeU size, SizeU align){
  SizeU mask = align - 1;
  SizeU val = size & mask;
  if(val){
    val = align - val;
  }
  return val;
}

function SizeU
align_up(SizeU size, SizeU align){
  SizeU result = size + get_align_offset(size, align);
  return result;
}

function U64 
hash_fnv(String string) {
  U64 hash = (U64)14695981039346656037ULL;
  for (U64 i = 0; i < string.len; i++) {
    hash = hash ^ (U64)(string.str[i]);
    hash = hash * (U64)1099511628211ULL;
  }
  return hash;
}

function U64
is_pow2(U64 x) {
  assert(x != 0);
  B32 result = (x & (x - 1llu)) == 0;
  return result;
}

function U64 
wrap_around_pow2(U64 x, U64 power_of_2) {
  assert(is_pow2(power_of_2));
  U64 r = (((x)&((power_of_2)-1llu)));
  return r;
}

function B32
string_compare(String a, String b){
  if(a.len != b.len)
    return false;
  for(S64 i = 0; i < a.len; i++){
    if(a.str[i] != b.str[i])
      return false;
  }
  return true;
}

function U8
char_to_lower(U8 c){
  if(c >= 'A' && c <= 'Z')
    c += 32;
  return c;
}

function U8
char_to_upper(U8 c){
  if(c >= 'a' && c <= 'z')
    c -= 32;
  return c;
}

function String
string_to_lower(Arena *arena, String string){
  String result = arena_push_string_copy(arena, string);
  for(S64 i = 0; i < string.len; i++){
    result.str[i] = char_to_lower(result.str[i]);
  }
  return result;
}