Speeding up constant division in SBCL

by Erik Krisztián Varga for Steel Bank Common Lisp

Integer division is known to be a lot slower than other arithmetic operations like multiplication or addition in computers. Because of this, many compilers try to transform divisions into faster operations whenever possible. In particular, integer division by a constant value can be reduced to faster sequence of operations like shifting and multiplication. The aim of this project is to improve this in SBCL.