News for hackers. Stuff that matters.

A comment on Execution Units Are Often Pipelined. Parent comment

Re:Execution Units Are Often Pipelined by thesz on Monday December 30, 2024 @05:14PM (#42554126)
Adds are cheaper only for fixed-point computations. Floating point addition needs to denormalize one of its' arguments, perform an (integer) addition and then normalize the result.

Usually FP adds take a cycle or two longer than FP multiplication.

[ Parent | on HN ]
Re:Execution Units Are Often Pipelined by dahart on Monday December 30, 2024 @08:27PM (#42555473)
Depends on what you mean by ‘cheaper’. Multiplies are still more gates. The adds are slower due to longer dependency chains, not because they cost more gates.
[ Parent | on HN ]