Re: Block reording.
10 Mar 2007 21:34:31 -0500

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Related articles
Block reording. (2007-03-08)
Re: Block reording. (2007-03-10)
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Newsgroups: comp.compilers
Date: 10 Mar 2007 21:34:31 -0500
Organization: Compilers Central
References: 07-03-034
Keywords: analysis
Posted-Date: 10 Mar 2007 21:34:31 EST

On Mar 8, 5:52 pm, wrote:

> The code is simple to generate if I only use long distance jumps for
> je, since then every block is the same size and every jump is more
> or less equal in cost. However, a jump to an arbitrary point is 6
> bytes of machine code, where as a jump to a nearby point can be sone
> in only 2 bytes. Naturally, I'd rather use as many short jumps as
> possible, but this requires some strategy to reorder the blocks and
> switching from a 6 byte jump to a 2 byte has the potential to affect
> the distances of a large number of the other jumps. And the
> shrinking of the code size may allow other short jumps to be used,
> etc...

Just to clarify, I have a simple scheme scans through the blocks,
inserting short jumps if possible (noting that the switch to a short
jump may make it possible). This process is repeated until it can't


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