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Re: An unusual Performance approach using Synthetic registers
- From: Andy Walker <ja_walker at earthlink dot net>
- To: dewar at gnat dot com (Robert Dewar),lord at emf dot net
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 6 Jan 2003 23:19:00 -0600
- Subject: Re: An unusual Performance approach using Synthetic registers
- References: <20030106202439.01801F2CB6@nile.gnat.com>
On Monday 06 January 2003 02:24 pm, Robert Dewar wrote:
> > In other words, with synthregs, the CPU can ship some value off to
> > memory and not care how long it takes to get there or to get back from
> > there -- because it also ships it off to the synthreg, which it
> > hypothetically has faster access to.
>
> But this "hypothesis" is wrong. memory used for spills or locals is exactly
> the same as memory used for "synthetic registers" [this fancy term is
> nothing more than a fancy name for a local temporary]. So there is no issue
> of having faster access to one or the other. It may of course be the case
> that in one case you get more competent code than the other, but if so, the
> fix is to fix incompetent code :-)
An interesting proposition that I had not considered. After Synthetic
registers get running well enough to be rationally evaluated, I may be
interested in revisiting this idea.
Andy