buf_set_u64() function
Sets @c num bits in @c _buffer, starting at the @c first bit, using the bits in @c value. This routine fast-paths writes of little-endian, byte-aligned, 64-bit words.
Arguments
_buffer
The buffer whose bits will be set. Do not use uninitialized buffer or clang static analyzer emits a warning.
first
The bit offset in @c _buffer to start writing (0-63).
num
The number of bits from @c value to copy (1-64).
value
Up to 64 bits that will be copied to _buffer.