Instead of flat schedules, we now use so-called schedule trees to represent the
execution order of the statements in a SCoP. Schedule trees make it a lot easier
to analyze, understand and modify properties of a schedule, as specific nodes
in the tree can be choosen and possibly replaced.
This patch does not yet fully move our DependenceInfo pass to schedule trees,
as some additional performance analysis is needed here. (In general schedule
trees should be faster in compile-time, as the more structured representation
is generally easier to analyze and work with). We also can not yet perform the
reduction analysis on schedule trees.
For more information regarding schedule trees, please see Section 6 of
https://lirias.kuleuven.be/handle/123456789/497238
llvm-svn: 242130
Named isl sets can generally have any name if they remain within Polly, but only
certain strings can be parsed by isl. The new names we create ensure that we
can always copy-past isl strings from Polly to other isl tools, e.g. for
debugging.
llvm-svn: 241787
This updated contains various changes to isl, including improvements to the
AST generator. For Polly, the most important change is a fix that unbreaks
builds on darwin (reported by: Jack Howard)
llvm-svn: 241048
Summary: Adding the flag to C++ source files emits a warning, hence we set the compile flag depending on the file's language.
Reviewers: grosser
Subscribers: Meinersbur, pollydev, llvm-commits
Projects: #polly
Differential Revision: http://reviews.llvm.org/D10809
llvm-svn: 240986
This is very preliminary support, but it seems to work for the most common case.
When observing more/different test cases, we can work on generalizing this.
llvm-svn: 240955
As Polly got a lot faster after the small-integer-optimization imath
patch, we now increase the compute out to optimize larger kernels. This
should also expose additional slow-downs for us to address.
In LNT this gives us a 3.4x speedup on 3mm, at a cost of a 2x increase in
compile time (now 0.77s). reg_detect, oorafft and adi also show some compile
time increases. This compile time cost is divided between more time in isl and
more time in LLVM's backends due to increased code size (versioning and tiling).
llvm-svn: 240840
In case we have modulo operations in the access function (supported since
r240518), the assumptions generated to ensure array accesses remain within
bounds can contain existentially quantified dimensions which results in more
complex and more difficult to handle integer sets. As a result LNT's linpack
benchmark started to fail due to excessive compile time.
We now just drop the existentially quantified dimensions. This should be
generally save, but may result in less precise assumptions which may
consequently make us fall back to the original (unoptimized) code more often. In
practice, these cases probably do not appear to often.
I had difficulties to extract a good test case, but fortunately our LNT bots
cover this one well.
llvm-svn: 240775
This removes old code that has been disabled since several weeks and was hidden
behind the flags -disable-polly-intra-scop-scalar-to-array=false and
-polly-model-phi-nodes=false. Earlier, Polly used to translate scalars and
PHI nodes to single element arrays, as this avoided the need for their special
handling in Polly. With Johannes' patches adding native support for such scalar
references to Polly, this code is not needed any more. After this commit both
-polly-prepare and -polly-independent are now mostly no-ops. Only a couple of
simple transformations still remain, but they are scheduled for removal too.
Thanks again to Johannes Doerfert for his nice work in making all this code
obsolete.
llvm-svn: 240766
Summary:
With small integer optimization (short: sio) enabled, ISL uses 32 bit
integers for its arithmetic and only falls back to a big integer library
(in the case of Polly: IMath) if an operation's result is too large.
This gives a massive performance boost for most application using ISL.
For instance, experiments with ppcg (polyhedral source-to-source
compiler) show speed-ups of 5.8 (compared to plain IMath), respectively
2.7 (compared to GMP).
In Polly, a smaller fraction of the total compile time is taken by ISL,
but the speed-ups are still very significant. The buildbots measure
compilation speed-up up to 1.8 (oourafft, floyd-warshall, symm). All
Polybench benchmarks compile in at least 9% less time, and about 20%
less on average.
Detailed Polybench compile time results (median of 10):
correlation -25.51%
covariance -24.82%
2mm -26.64%
3mm -28.69%
atax -13.70%
bicg -10.78%
cholesky -40.67%
doitgen -11.60%
gemm -11.54%
gemver -10.63%
gesummv -11.54%
mvt -9.43%
symm -41.25%
syr2k -14.71%
syrk -14.52%
trisolv -17.65%
trmm -9.78%
durbin -19.32%
dynprog -9.09%
gramschmidt -15.38%
lu -21.77%
floyd-warshall -42.71%
reg_detect -41.17%
adi -36.69%
fdtd-2d -32.61%
fdtd-apml -21.90%
jacobi-1d-imper -9.41%
jacobi-2d-imper -27.65%
seidel-2d -31.00%
Reviewers: grosser
Reviewed By: grosser
Subscribers: Meinersbur, llvm-commits, pollydev
Projects: #polly
Differential Revision: http://reviews.llvm.org/D10506
llvm-svn: 240689
There were two issues:
* ISL's configure generates include/isl/stdint.h, not isl/stdint.h as
assumed. This is also changed in the CMake build.
* Need to pass --with-int=imath to ISL's configure; the default is gmp.
Polly's configure has been regenerated due to changing configure.ac
llvm-svn: 240657
Remainder operations with constant divisor can be modeled as quasi-affine
expression. This patch adds support for detecting and modeling them. We also
add a test that ensures they are correctly code generated.
This patch was extracted from a larger patch contributed by Johannes Doerfert
in http://reviews.llvm.org/D5293
llvm-svn: 240518
This makes the test cases nonaffine even if Polly some days gains support for
the srem instruction, an instruction which is currently not modeled but which
can clearly be modeled statically. A call to a function without definition
will always remain non-affine, as there is just insufficient static information
for it to be modeled more precisely.
llvm-svn: 240458
ISL with small integer optimization requires C99 to compile. gcc < 5.0
still uses C89 as default, so we need to enable the options to compile
in C99 mode.
This patch is preparing the actual activation of small integer
optimization.
Differential version: http://reviews.llvm.org/D10610
Reviewers: grosser
llvm-svn: 240322
ISL's ./configure examines the system for the stdint.h to include and
creates a header file that points to it. On C99-compatible system
#include <stdint.h>
is always valid such there no need for system introspection. This should
unbreak the build bots.
llvm-svn: 240315
The 'make dist' archive is not dependent on ./configure output and
contains a GIT_HEAD_ID file that identifies the version of ISL used.
None of the files added or removed are used part of Polly's build
process (except of GIT_HEAD_ID since the previous revision r240301). No
functional change intended.
llvm-svn: 240306
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
This was meant to committed in r240027, but was left behind because
svn, in contrast to git, only commits the changes in the directory you
are currently in.
llvm-svn: 240034
This version adds small integer optimization, but is not active by
default. It will be enabled in a later commit.
The schedule-fuse=min/max option has been replaced by the
serialize-sccs option. Adapting Polly was necessary, but retaining the
name polly-opt-fusion=min/max.
Differential Revision: http://reviews.llvm.org/D10505
Reviewers: grosser
llvm-svn: 240027
LLVM's instcombine already translates power-of-two sdivs that are known to be
exact to fast ashr instructions. Hence, there is no need to add this logic
ourselves.
Pointed-out-by: Johannes Doerfert
llvm-svn: 239025
We now verify that memory access functions imported via JSON are indeed defined
for the full iteration domain. Before this change we accidentally imported
memory mappings such as i -> i / 127, which only defined a mapped for values of
i that are evenly divisible by 127, but which did not define any mapping for the
remaining values, with the result that isl just generated an access expression
that had undefined behavior for all the unmapped values.
In the incorrect test cases, we now either use floor(i/127) or we use p/127 and
provide the information that p is indeed a multiple of 127.
llvm-svn: 239024
floord(a,b) === a ashr log_2 (b) holds for positive and negative a's, but
shifting only makes sense for positive values of b. The previous patch did
not consider this as isl currently always produces postive b's. To avoid future
surprises, we check that b is positive and only then apply the optimization.
We also now correctly check the return value of the dyn-cast.
No additional test case, as isl currently does not produce negative
denominators.
Reported-by: David Majnemer <david.majnemer@gmail.com>
llvm-svn: 238927
Tobias Grosser