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Re: An unusual Performance approach using Synthetic registers, and a request for guidance.
- From: Andy Walker <ja_walker at earthlink dot net>
- To: Dave Hudson <dave at cyclicode dot net>
- Cc: gcc at gcc dot gnu dot org
- Date: Sat, 28 Dec 2002 23:35:09 -0600
- Subject: Re: An unusual Performance approach using Synthetic registers, and a request for guidance.
- References: <000701c2ad9e$a85adbc0$ec111897@bonz> <3E0CC555.9080108@cyclicode.net>
On Friday 27 December 2002 03:25 pm, Dave Hudson wrote:
<snip>
>
> This strategy is exactly what the IP2k port of gcc does. We use 32
> directly addressable memory locations as our common "registers" and
> expose the two pointer and stack pointer regs. We completely hide the
> accumulator register W and the partial multiply result MULH. All of our
> normal insn patterns start off not understanding anything about the
> hidden regs and then in the machine-dependent reorg we split insn
> patterns into ones that explicitly use the previously hidden regs and
> run a series of processor-specific passes to eliminate any redundancy.
>
> It's not pretty, but it does work very well.
Then this approach is not completely insane. Thank you.
Andy
>
> Regards,
> Dave