Bug: GMP 4.2.1 will not build as x86 fat binary
tege at swox.com
Tue May 16 11:43:47 CEST 2006
A non-text attachment was scrubbed...
Size: 3865 bytes
Desc: not available
Url : http://gmplib.org/list-archives/gmp-bugs/attachments/20060516/67d258d5/foo.obj
-------------- next part --------------
<librik at panix.com> writes:
GMP 4.2.1 will not build as an x86 fat binary. It is missing the
functions mpn_add_nc and mpn_sub_nc, which mpn/generic/addsub_n.c
The "fat mpn" mechanism does not make mpn_add_nc() and mpn_sub_nc()
available, although mpn_add_n() and mpn_sub_n() are provided.
(Each of the CPU-specific *_add_n.asm/*_sub_n.asm files does provide
its own version of mpn_add_nc and mpn_sub_nc, but the fat.c system
doesn't pick them up and use them to make a "master" mpn_add_nc or
mpn_sub_nc. They're not in the CPUVEC. I don't know why not.)
When a "fat binary" is built, almost none of the HAVE_NATIVE macros
are defined in config.h:
/* Define to 1 each of the following for which a native (ie. CPU specific)
implementation of the corresponding routine exists. */
/* #undef HAVE_NATIVE_mpn_add_n */
/* #undef HAVE_NATIVE_mpn_add_nc */
.... etc. etc. ...
I suppose this ought to be fixed, but it seems difficult to ix it.
Maybe you're the right person to look into it?
For a fat build, one can only define HAVE_NATIVE_X if X is defined for
every identifiable processor, of course.
(1) Add mpn_add_nc and mpn_sub_nc to the list of functions made
available by fat.c. This means adding it to the CPUVEC.
(I think this is the right thing to do, because why should a
GMP operation available in every x86 CPU-specific binary not
be available in the x86 "fat binary"?)
However, this requires changes in fat.c, x86-defs.m4, and
something complicated inside configure. It's a bit beyond
my expertise, unfortunately.
Supposedly, one just needs to add add_nc whereever add_n is mentioned.
(2) Rewrite addsub_n.c so it uses mpn_add_n() and mpn_sub_n()
exclusively, not relying on mpn_add_nc() or mpn_sub_nc().
As per the patch above.
More information about the gmp-bugs