Most of mul/div was implemented in hardware since the 80186 (and the more or less compatible NEC V30 too). The microcode only loaded the operands into internal

Most of mul/div was implemented in hardware since the 80186 (and the more or less compatible NEC V30 too). The microcode only loaded the operands into internal ALU registers, and did some final adjustment at the end. But it was still done as a sequence of single bit shifts with add/sub, taking one clock cycle per bit.