[llvm-commits] [PATCH] MCAssembler Performance: Lazy invalidation

[David Meyer]

I retract this patch at the moment...  I forgot to fix a problem with it.

Will submit a new one shortly.

- David Meyer


On Tue, Dec 14, 2010 at 9:29 AM, David Meyer <pdox at google.com> wrote:

> This patch moves invalidation of the layout until after all relaxations
> have occurred.
>
> This prevents wasting time recomputing portions of the layout over and
> over. Computing the layout is expensive, so we want to use as much of the
> information generated each time as possible, instead of throwing it away
> each  time a relaxation happens.
>
> This removes a hidden O(n^2) runtime factor (where n is the number of
> fragments) which causes terrifying performance problems when assembling
> really large .s file with lots of relaxable instructions.
>
> - David Meyer
>
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