+++
title = "Problem with chaining in general"
date = "2022-05-17"
author = "Yann Herklotz"
tags = []
categories = []
backlinks = ["1c4"]
forwardlinks = ["1c4b"]
zettelid = "1c4a"
+++

The main problem with operation chaining in the current implementation
of scheduling is that intermediate instructions limits the use of
multiply and add (MAC) operations that are present in DSPs. This is
because the synthesis tool cannot know if the register is used again,
and therefore can't use a MAC operation directly, but instead has to do
a multiply, store the result in a register, and then do an add, which
will probably be in logic. This introduces a long delay and therefore
heavily slows down the clock.