[clug] assembly performance

Martin Pool mbp at sourcefrog.net
Fri Jun 10 01:32:18 GMT 2005

On  8 Jun 2005, Adrian Blake <A.Blake at physics.usyd.edu.au> wrote:
> This is a question about microprocessor architecture.
> 10 or 20 years ago assembly code addressed physical hardware, registers 
> ALUs and alike with an underlying simple microcode.
> This has changed. but to what extent?
> Does assembly code still operate on the physical hardware or is it  a 
> virtual machine with one or more layers of microcode? 

I think any modern large processor has some degree of microcoding.
Whether that makes it a virtual machine or not rather depends on which
definition you choose to use.

> What are the performance penalties if any?

Penalties compared to what?  One could presumably always make chips
faster by adding more gates and/or spending more time on low-level
design rather than using microcode, but at what price?


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