From: Mike Stump <mikestump@comcast.net>
To: Richard Sandiford <rdsandiford@googlemail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: PR 61136: wide-int fallout in int_const_binop_1
Date: Sat, 10 May 2014 23:45:00 -0000 [thread overview]
Message-ID: <6FEE9EBD-0D0B-4033-8184-931D2B1D799D@comcast.net> (raw)
In-Reply-To: <87r4411mat.fsf@talisman.default>
On May 10, 2014, at 12:11 PM, Richard Sandiford <rdsandiford@googlemail.com> wrote:
> The new conversion can't be right because it loses overflow information.
> The question then is whether this function should be prepared to handle
> mismatched arguments (as the pre-wide-int version effectively did, since
> it did everything in double_int precision) or whether the operation
> should be strictly typed. If the former then the function should be
> doing the calculation in widest_int, which would make it a much more
> direct analogue of the original code. If the latter then we should be
> able to operate directly on arg2.
I think I caused this, but I don’t think I had a deep reason for doing it, just trying to bring them to a common type.
I think a fold person should weigh in.
> I tried making int_const_binop_1 strictly typed and the only thing
> that was needed to pass bootstrap was a fairly obvious-looking patch
> to the Ada frontend. But there's quite a bit of fallout in the testsuite
> itself (including the above).
> This patch therefore uses wi:: directly.
> I think this is worth doing independently of the eventual patches to fix
> the type incompatibilities elsewhere.
I think that seems fine.
> OK to install?
Ok.
next prev parent reply other threads:[~2014-05-10 23:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-10 19:11 Richard Sandiford
2014-05-10 23:45 ` Mike Stump [this message]
2014-05-11 12:23 ` Richard Biener
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