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From: Richard Sandiford <richard.sandiford@arm.com>
To: Andreas Schwab <schwab@suse.de>
Cc: "David Sherwood" <david.sherwood@arm.com>,
	 <gcc-patches@gcc.gnu.org>,  <vmakarov@redhat.com>
Subject: Re: Fix for "FAIL: tmpdir-gcc.dg-struct-layout-1/t028 c_compat_x_tst.o compile, (internal compiler error)"
Date: Tue, 30 Sep 2014 11:09:00 -0000	[thread overview]
Message-ID: <87y4t1jreq.fsf@e105548-lin.cambridge.arm.com> (raw)
In-Reply-To: <mvmwq8liky8.fsf@hawking.suse.de> (Andreas Schwab's message of	"Tue, 30 Sep 2014 10:14:39 +0200")

Andreas Schwab <schwab@suse.de> writes:
> Richard Sandiford <richard.sandiford@arm.com> writes:
>
>> @@ -315,7 +318,7 @@ struct ira_allocno
>>       number (0, ...) - 2.  Value -1 is used for allocnos spilled by the
>>       reload (at this point pseudo-register has only one allocno) which
>>       did not get stack slot yet.  */
>> -  short int hard_regno;
>> +  int hard_regno : 16;
>
> If you want negative numbers you need to make that explicitly signed.

Are you sure?  In:

  struct { int i : 16; unsigned int j : 1; } x = { -1, 0 };
  int foo (void) { return x.i; }

foo returns -1 rather than 65535.  I can't see any precedent in gcc/*.[hc]
for explicitly marking bitfields as signed.

Thanks,
Richard

  reply	other threads:[~2014-09-30 11:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-26 14:26 David Sherwood
2014-09-30  8:05 ` Richard Sandiford
2014-09-30  8:14   ` Andreas Schwab
2014-09-30 11:09     ` Richard Sandiford [this message]
2014-09-30 11:51       ` Andreas Schwab
2014-09-30 13:53         ` Richard Earnshaw
2014-09-30 16:15           ` Joseph S. Myers
2014-09-30 19:34             ` Mike Stump
2014-10-01  8:50               ` Richard Earnshaw
2014-10-01 12:18                 ` Mike Stump
2014-10-01  7:26             ` Andreas Schwab
2014-10-01  7:28               ` David Sherwood
2014-10-03 10:18                 ` Richard Sandiford
  -- strict thread matches above, loose matches on Subject: below --
2014-09-08 11:48 David Sherwood
2014-09-05 14:52 David Sherwood
2014-09-09 20:18 ` Vladimir Makarov

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