Messages in this thread | | | Date | Mon, 14 Jan 2002 17:35:31 +1100 | From | Anton Blanchard <> | Subject | Re: results: Remove 8 bytes from struct page on 64bit archs |
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> The powerpc backend claims to have a fast divide instruction > (via RTX_COST if you care about such things). We'll replace > with shift when dividing by powers of 2, but won't try the > multiply by a constant inverse trick.
To follow up: Alan Modra found and fixed the bug, it seems we were only using the optimisation when the arguments were <= 32bit.
The target we use is RS64a which has a cost of 60 odd instructions for divide.
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