On 29 November 2017 at 13:42, Laurent Vivier <laur...@vivier.eu> wrote: > these functions come from: > > http://previous.alternative-system.com/ > > http://svn.code.sf.net/p/previous/code/trunk/src/softfloat/softfloat.c > > This is also a modified softfloat, release 2b > which is BSD license if I'm correct.
We can't use softfloat2b code (the part of the license that goes "USE OF THIS SOFTWARE IS RESTRICTED TO PERSONS AND ORGANIZATIONS [...] WHO FURTHERMORE EFFECTIVELY INDEMNIFY JOHN HAUSER AND THE INTERNATIONAL COMPUTER SCIENCE INSTITUTE" isn't GPL compatible). We can use softfloat2a code, which doesn't have that indemnity clause. > http://svn.code.sf.net/p/previous/code/trunk/src/softfloat/README.txt > > and MAME is GPL: > http://mamedev.org/legal.html > > and Previous is a fork of Hatari (GPL), a fork of UAE (GPL) > https://hatari.tuxfamily.org/index.html > > This code has also been copied to WinUAE (GPL), where softfloat has been > copied from QEMU: > https://github.com/tonioni/WinUAE/blob/master/softfloat/softfloat.cpp Yes, lots of projects used the softfloat2b code without realising it wasn't GPL compatible (including QEMU -- we had a painful job to fix things up and convert to the 2a codebase a while back). > But I think the bad news comes later: > > all the other functions (sin, cos, tan, log, exp, ...) found in previous > (softfloat_fpsp.c) are "derived" from NeXT library FPSP: > > http://svn.code.sf.net/p/previous/code/trunk/src/softfloat/softfloat_fpsp.c > > /*============================================================================ > > This C source file is an extension to the SoftFloat IEC/IEEE Floating-point > Arithmetic Package, Release 2a. > > Written by Andreas Grabher for Previous, NeXT Computer Emulator. > > =============================================================================*/ > ... > /*---------------------------------------------------------------------------- > | Algorithms for transcendental functions supported by MC68881 and MC68882 > | mathematical coprocessors. The functions are derived from FPSP library. > *----------------------------------------------------------------------------*/ > > FPSP library can be found: > > https://ftp.nice.ch/pub/next/developer/hardware/m68k/ > > And the assembly source code is not free at all: > > https://ftp.nice.ch/pub/next/developer/hardware/m68k/_libFPSP.1.p2.N.s/l_fpsp.h > > > | Copyright (C) Motorola, Inc. 1991 > | All Rights Reserved > | > | THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA > | The copyright notice above does not evidence any > | actual or intended publication of such source code. > > > So I'm wondering what license apply to the C version found in "Previous". Good question. It's clearly not copied code (since the FPSP library is all native m68k assembly), but presumably it's the same algorithms transliterated into C... thanks -- PMM