document isl_{set,map}_set_tuple_name

Reported-by: Uday R Bondhugula <uday@csa.iisc.ernet.in>
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
isl_gmp.c: remove spurious include

The include appears to have been introduced by mistake in 0a83197
(try and avoid depending on mpz_gcdext internals,
Wed Jun 19 11:22:18 2013 +0200).

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
isl_val_gcdext: revert to open-coded version of isl_int_gcdext

In 10a7f8a (isl_ast_build.c: use isl_int_gcdext instead of open-coded version,
Wed Apr 17 17:51:55 2013 +0200), the open-coded version was replaced
by a call to the isl_int_gcdext macro introduced in e191579
(add isl_int_gcdext, Wed Apr 17 17:51:28 2013 +0200).
In 0a83197 (try and avoid depending on mpz_gcdext internals,
Wed Jun 19 11:22:18 2013 +0200), we introduced a isl_gmp_gcdext
to try and mask differences in the outcomes of the underlying
mpz_gcdext over different versions of GMP.

However, there is no guarantee that we caught all the differences.
Furthermore, we will be introducing an alternative to GMP soon and
the differences across libraries are likely to be even greater than
those between different versions of the same library.

We therefore revert back to our (slightly modified) original implementation.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
configure.ac: move gmp detection to a separate file

Move the code to detect the GMP lib to a separate file to simplify
the next commit.

Signed-off-by: Sebastian Pop <spop@codeaurora.org>
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
optionally use imath for arbitrary precision integers

Some projects such as LLVM and Polly prefer not to use any
LGPL licensed libraries such as GMP.  The optional use of
the MIT licensed IMath library allows them to avoid this.

IMath is included as a submodule to ensure that a single
version of IMath is used for any given version of isl.
The public symbols are prefixed with isl_ to avoid conflicts
with other copies of IMath that may independently be used by
the users of isl.

The deprecated isl_int functions are not supported when IMath is used
since they depend on GMP.  We rename them when IMath is used to ensure
that any attempt to use them in an IMath enabled isl results in
a linker error.

The subdir-objects automake option is turned on since this is the
first time we use source files in subdirectories and since this
option will become the default in future versions of automake.

Signed-off-by: David Peixotto <dpeixott@codeaurora.org>
Signed-off-by: Sebastian Pop <spop@codeaurora.org>
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>