Bug in loop optimize (invalid postinc to preinc transformation)

[Alexandre Oliva]

On Dec 27, 2000, Peter Osterlund <peter.osterlund@mailbox.swipnet.se> wrote:

> Compiling without optimization indicates that the compiler is
> transforming (p++ < x) into (++p < (x+1)), even when not optimizing.
> This transformation is incorrect because x+1 wraps around.

Overflow invokes undefined behavior.  Since incrementing p in this
case involves overflow, I think the transformation is ok, as far as
undefined behavior goes.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
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