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Re: Loop unrolling


mrs@wrs.com (Mike Stump) said:

[...]

> Well, this wasn't the result of the consersation when last we agreed
> on what to do and what the doc meant and what the compiler should do.
> The decision whether or not a loop could be removed was to be decided
> by the source input tokens to the lexer.  Not by the existing rtl
> codes.

That is a horribly broken idea. That way you have to get non-standard
lexical information down to the loop-optimizer. The data paths for that
surely aren't in place, and would just add gratuitous complexity. All just
for supporting a broken feature.

There are non-intrusive solutions, like the asm volatile ("" : : : "r(i)")
idea. If somebody wants to do something like this, they deserve to have to
write it this way, IMHO.
-- 
Horst von Brand                             vonbrand@sleipnir.valparaiso.cl
Casilla 9G, Viņa del Mar, Chile                               +56 32 672616


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