From: Robert Lipe <robertlipe@usa.net>
To: "David A. Greene" <greened@eecs.umich.edu>
Cc: "Martin v. Loewis" <martin@mira.isdn.cs.tu-berlin.de>,
egcs@egcs.cygnus.com
Subject: Re: egcs and bitfields
Date: Fri, 12 Mar 1999 08:48:00 -0000 [thread overview]
Message-ID: <19990312104540.D1570@rjlhome.sco.com> (raw)
In-Reply-To: < 36E92F61.5951621@eecs.umich.edu >; from David A. Greene on Fri, Mar 12, 1999 at 10:14:41AM -0500
> #include <stdio.h>
>
> struct foo { int c:3; } x = { 7 };
>
> int main(void)
> {
> printf("%d\n", x.c);
>
> return(0);
> }
>
> >>-drakh-> egcc fieldinit.c
> >>-drakh-> ./a.out
> -1
>
> I think the output should be 7, since an "int"
> bitfield is supposed
> to be unsigned according to the i386 SysV ABI.
While I can't comment on any correctness issues in the example or
pertinence of various ABI specs, I can confirm that your example behaves
differently on different System V/386's.
On OpenServer:
/bin/cc -1
egcs 1.1.1 -1
icc 7
udk cc 7
On UnixWare 7.0.1
/bin/cc 7
egcs 1.1.1 -1
Note that /bin/cc on SVR5 is essentially the same as UDK on OSR5. Since
/bin/cc on OpenServer had parentage in the code that became those two
compilers, I'm guessing that it was an intentional ABI change between
the OpenServer lineage (more iBCS2-ish) and the SVR4 lineage.
RJL
WARNING: multiple messages have this Message-ID
From: Robert Lipe <robertlipe@usa.net>
To: "David A. Greene" <greened@eecs.umich.edu>
Cc: "Martin v. Loewis" <martin@mira.isdn.cs.tu-berlin.de>,
egcs@egcs.cygnus.com
Subject: Re: egcs and bitfields
Date: Wed, 31 Mar 1999 23:46:00 -0000 [thread overview]
Message-ID: <19990312104540.D1570@rjlhome.sco.com> (raw)
Message-ID: <19990331234600.NYp7-MJpgxwoRAgYVhSsbEIOcryWCvUUpRJNdvjzY8M@z> (raw)
In-Reply-To: <36E92F61.5951621@eecs.umich.edu>
> #include <stdio.h>
>
> struct foo { int c:3; } x = { 7 };
>
> int main(void)
> {
> printf("%d\n", x.c);
>
> return(0);
> }
>
> >>-drakh-> egcc fieldinit.c
> >>-drakh-> ./a.out
> -1
>
> I think the output should be 7, since an "int"
> bitfield is supposed
> to be unsigned according to the i386 SysV ABI.
While I can't comment on any correctness issues in the example or
pertinence of various ABI specs, I can confirm that your example behaves
differently on different System V/386's.
On OpenServer:
/bin/cc -1
egcs 1.1.1 -1
icc 7
udk cc 7
On UnixWare 7.0.1
/bin/cc 7
egcs 1.1.1 -1
Note that /bin/cc on SVR5 is essentially the same as UDK on OSR5. Since
/bin/cc on OpenServer had parentage in the code that became those two
compilers, I'm guessing that it was an intentional ABI change between
the OpenServer lineage (more iBCS2-ish) and the SVR4 lineage.
RJL
next prev parent reply other threads:[~1999-03-12 8:48 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-03-11 14:33 David A. Greene
[not found] ` < 36E844B2.8DAEFAAF@eecs.umich.edu >
1999-03-11 15:14 ` Martin v. Loewis
[not found] ` < 199903112300.AAA19947@mira.isdn.cs.tu-berlin.de >
1999-03-11 15:41 ` Robert Lipe
1999-03-31 23:46 ` Robert Lipe
1999-03-12 7:16 ` David A. Greene
[not found] ` < 36E92F61.5951621@eecs.umich.edu >
1999-03-12 8:48 ` Robert Lipe [this message]
[not found] ` < 19990312104540.D1570@rjlhome.sco.com >
1999-03-12 9:41 ` Doug Semler
[not found] ` < 199903121741.JAA24401@vortex.seaspace.com >
1999-03-12 9:59 ` Robert Lipe
1999-03-31 23:46 ` Robert Lipe
1999-03-12 13:26 ` Martin v. Loewis
[not found] ` < 199903122118.WAA00520@mira.isdn.cs.tu-berlin.de >
1999-03-12 13:52 ` Doug Semler
1999-03-31 23:46 ` Doug Semler
1999-03-31 23:46 ` Martin v. Loewis
1999-03-31 23:46 ` Doug Semler
1999-03-31 23:46 ` Robert Lipe
1999-03-12 9:27 ` Martin v. Loewis
1999-03-12 10:47 ` David A. Greene
1999-03-31 23:46 ` David A. Greene
1999-03-31 23:46 ` Martin v. Loewis
1999-03-31 23:46 ` David A. Greene
1999-03-31 23:46 ` Martin v. Loewis
1999-03-31 23:46 ` David A. Greene
1999-03-12 7:20 David A. Greene
1999-03-31 23:46 ` David A. Greene
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