Query the isl_config.h macros recently added to ISL. One of it looks for
the ffs (find first set), whose functionality is available in Visual
Studio with _BitScanForward. Also add isl_ffs.c to the source files
which contains the implementation of ffs using _BitScanForward.
Reviewers: grosser
llvm-svn: 242770
Currently the Polly repository contains the ISL sources with bogus
isl_config.h and gitversion.h. This is problematic. In this state a
macro
#define __attribute__(x)
becomes active in the source, leading to various problems e.g. when
included before system header files. This patch will instead generate
the two files specific to the host system at configure-time.
For CMake, we replicate the tests that ISL's configure performs using
try_compile(). In autotools build, we just invoke ISL's configure to
generate the two files. This consequently required regenerating
autoconf/configure.
'make dist' distributions of ISL contain a file GIT_HEAD_ID which
contains the version the distribution is derived from. The repository
files themselves do not contain such a hint. In a later commit we will
replace the isl directory by the contents of such a .tar.gz. It does
not contain the files imdrover.c iprime.c pi.c and rsamath.c currently
compiled into Polly, but not used and therefore are removed by this
patch.
In the long term we plan to generate a dedicated library for ISL instead
of adding its files to Polly.
This also does not yet include the switch to small-integer optimized ISL
nor enabling C99 mode required for the former. Those will come as well
in separate patches.
Differential version: http://reviews.llvm.org/D10603
Reviewers: grosser
llvm-svn: 240301
Michael Kruse