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From: Jason Merrill <jason@redhat.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Andreas Schwab <schwab@suse.de>,
	gcc-patches List <gcc-patches@gcc.gnu.org>
Subject: Re: C++ PATCH to add __integer_pack built-in for std::make_integer_sequence (c++/80396)
Date: Wed, 24 May 2017 18:50:00 -0000	[thread overview]
Message-ID: <CADzB+2mLdxBk2Hw9Gw4S-GjM9ZmaT+u+cKStMD=nk0eFc29daQ@mail.gmail.com> (raw)
In-Reply-To: <20170524150823.GK8499@tucnak>

On Wed, May 24, 2017 at 11:08 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Wed, May 24, 2017 at 04:16:30PM +0200, Andreas Schwab wrote:
>> FAIL: g++.dg/ext/integer-pack2.C  -std=gnu++11 (test for excess errors)
>> Excess errors:
>> /daten/aranym/gcc/gcc-20170524/gcc/testsuite/g++.dg/ext/integer-pack2.C:10:48: error: overflow in constant expression [-fpermissive]
>> /daten/aranym/gcc/gcc-20170524/gcc/testsuite/g++.dg/ext/integer-pack2.C:10:48: error: overflow in constant expression [-fpermissive]
>
> To be precise, it fails only on 32-bit targets.

> If we at that point want some wider integer that when cast to int
> is 0 (or small enough positive number?), shall we use something like
> this, or say 1LL << (sizeof (int) * __CHAR_BIT__), or 2LL * INT_MIN,
> something else?

This is fine.

> Do we need to include <limits.h>?  Or can we replace
> INT_MAX with __INT_MAX__?

__INT_MAX__ sounds good.

> Not sure about that -2147483650 for 16-bit int targets (perhaps the test can
> be guarded with int32 effective target).

Yes, restricting the test to int32 seems like the easiest fix.

Jason

  reply	other threads:[~2017-05-24 18:47 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-23 20:27 Jason Merrill
2017-05-24 14:18 ` Andreas Schwab
2017-05-24 15:17   ` Jakub Jelinek
2017-05-24 18:50     ` Jason Merrill [this message]
2017-05-24 19:13       ` Jakub Jelinek

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