LUA : An easy way to separate an int64 into two int32 ?

[admin]

@Erwin, you example splits 32 bits into two 16 bit values. Lua bit operations work only with 32 bit numbers. FFI can be used to convert between different types:

Code:

function u64_to_u32(value)
  local ffi = require('ffi')
  local u64 = ffi.new('uint64_t[1]', value)
  local u32 = ffi.new('uint32_t[2]')
  ffi.copy(u32, u64, 8)
  return u32[0], u32[1]
end

value = math.pow(2, 53) - 1 -- some large value

u32_l, u32_h = u64_to_u32(value)
log(u32_l, u32_h)