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Re: [PATCH] Fix extract_range_from_cond (PR tree-optimization/19060)
On Wed, Jan 05, 2005 at 11:49:45AM -0700, Jeffrey A Law wrote:
> > value of the second extract_range_from_cond. I haven't so far managed to
> > write a testcase that would prove that it is wrong, but I certainly don't
> > understand how that can be right.
>
>
> It works right now because we never record any ranges which need to be
> inverted. Thus we "know" that the inverted flag will never be set by
> the second call to extract_range_cond (for the same reason we can ignore
> the return value from the second call to extract_range_cond). It
> wouldn't hurt to put in a couple asserts.
Ok.
> Your change as it stands means we could need the inverted bit on
> stored ranges and thus I believe could introduce regressions.
>
> We're probably best off doing two things:
>
> 1. Fixing fold so that it handles x < TYPE_MIN_VALUE (TREE_TYPE (x))
> (I thought it did that already, so we need to figure out why it
> didn't trigger).
>
> 2. For GT TYPE_MAX_VALUE, don't record anything. Simliarly for
> LT TYPE_MIN_VALUE.
Ok, I'll handle 1. and 2. (plus add assert about dummy == 0).
Jakub