Re: [PATCH] use all same precision in wide_int arguments (PR 93986)

[Martin Sebor <msebor at gmail dot com>]

On 3/3/20 2:42 AM, Richard Biener wrote:
> On Tue, Mar 3, 2020 at 12:04 AM Martin Sebor <msebor@gmail.com> wrote:
> > The wide_int APIs expect operands to have the same precision and
> > abort when they don't.  This is especially insidious in code where
> > the operands normally do have the same precision but where mixed
> > precision arguments can come up as a result of unusual combinations
> > optimization options.  That is also what precipitated pr93986.
>
> If you want sth like (signed) arbitrary precision arithmetic then you can
> use widest_int instead.  Or, since you're working with offsets, offset_int
> is another good choice.

Yes, I would much prefer not to have to do all this myself (and
risk getting it wrong).  Unfortunately, the APIs that obtain
the ranges all use wide_int, so I'd have to convert them one way
or the other.  I could change some of the APIs but not all of
them (e.g., get_range_info).

Martin


> > The attached patch adjusts the code to extend all wide_int operands
> > to the same precision to avoid the ICE.
> >
> > Besides the usual bootstrap/testing I also compiled all string tests
> > in gcc.dg with the same options as in the test case in pr93986 in
> > an effort to weed out any lingering bugs like it (found none).
> >
> > Martin