Re: Code optimization <LEA Instruction>

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Fri Jan 28 2000 - 09:37:52 EST


> The test shows that LEA should not be arbitrarily used for arithmetic on
> an index register. It clearly shows that addition is faster.

Arbitarily no, general case it should be.

> It was written to demonstrate this. It demonstrates this. Alan assumed

You wrote a demo for AGI generation stalls not for lea performance when
compiler scheduled. Most x86 chips have a single AGI generator so you
just stalled your cpu a lot.

Alan

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