This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: Reversing bitfields on solaris

From: Jim Wilson <wilson at tuliptree dot org>
To: Samaresh Pradhan <samaresh_pradhan at filemaker dot com>
Cc: gcc at gcc dot gnu dot org
Date: Tue, 10 Jun 2003 10:55:25 -0700
Subject: Re: Reversing bitfields on solaris
References: <NEBBLEIBINIHLEOMHNFLCEAHCFAA.samaresh_pradhan@filemaker.com>

Samaresh Pradhan wrote:

I am porting an app from Windows (Visual C++) to Solaris (g++). This
application has encryption and decryption algorithm based on bit position
for given values.

x86 Windows is little-endian, and sparc Solaris is big-endian, so yes the bit positions for bit-fields are reversed.

We don't have any support for reversing bit-fields. It might be reasonable to add an attribute for this, but it is unlikely anyone will volunteer to do the work for you.

A common way of doing this is to have two structure definitions with their bitfields reversed, and then use #ifdef to choose the right one for the target.

Jim

References:
- Reversing bitfields on solaris
  - From: Samaresh Pradhan

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]