llvm-project/polly
Michael Kruse 7886bd7ca5 Add -polly-flatten-schedule pass.
The -polly-flatten-schedule pass reduces the number of scattering
dimensions in its isl_union_map form to make them easier to understand.
It is not meant to be used in production, only for debugging and
regression tests.

To illustrate, how it can make sets simpler, here is a lifetime set
used computed by the porposed DeLICM pass without flattening:

    { Stmt_reduction_for[0, 4] -> [0, 2, o2, o3] : o2 < 0;
      Stmt_reduction_for[0, 4] -> [0, 1, o2, o3] : o2 >= 5;
      Stmt_reduction_for[0, 4] -> [0, 1, 4, o3] : o3 > 0;
      Stmt_reduction_for[0, i1] -> [0, 1, i1, 1] : 0 <= i1 <= 3;
      Stmt_reduction_for[0, 4] -> [0, 2, 0, o3] : o3 <= 0 }

And here the same lifetime for a semantically identical one-dimensional
schedule:

    { Stmt_reduction_for[0, i1] -> [2 + 3i1] : 0 <= i1 <= 4 }

Differential Revision: https://reviews.llvm.org/D24310

llvm-svn: 280948
2016-09-08 15:02:36 +00:00
..
cmake Add missing words to wanrning. 2016-08-25 13:29:26 +00:00
docs docs: Remove reference to PoCC 2016-05-17 19:44:16 +00:00
include/polly Add -polly-flatten-schedule pass. 2016-09-08 15:02:36 +00:00
lib Add -polly-flatten-schedule pass. 2016-09-08 15:02:36 +00:00
test Add -polly-flatten-schedule pass. 2016-09-08 15:02:36 +00:00
tools GPGPU: Cache PTX kernels 2016-08-04 09:15:58 +00:00
unittests Add -polly-flatten-schedule pass. 2016-09-08 15:02:36 +00:00
utils Revise polly-{update|check}-format targets 2015-09-14 16:59:50 +00:00
www Add forgotten image 2016-08-30 12:41:29 +00:00
.arcconfig Upgrade all the .arcconfigs to https. 2016-07-14 13:15:37 +00:00
.arclint Adjusted arc linter config for modern version of arcanist 2015-08-12 09:01:16 +00:00
.gitattributes gitattributes: .png and .txt are no text files 2013-07-28 09:05:20 +00:00
.gitignore Add git patch files to .gitignore 2015-06-23 20:55:01 +00:00
CMakeLists.txt Query llvm-config to get system libs required for linking. 2016-08-25 14:58:29 +00:00
CREDITS.txt Add myself to the credits 2014-08-10 03:37:29 +00:00
LICENSE.txt Update copyright year to 2016. 2016-03-30 22:41:38 +00:00
README

README

Polly - Polyhedral optimizations for LLVM
-----------------------------------------
http://polly.llvm.org/

Polly uses a mathematical representation, the polyhedral model, to represent and
transform loops and other control flow structures. Using an abstract
representation it is possible to reason about transformations in a more general
way and to use highly optimized linear programming libraries to figure out the
optimal loop structure. These transformations can be used to do constant
propagation through arrays, remove dead loop iterations, optimize loops for
cache locality, optimize arrays, apply advanced automatic parallelization, drive
vectorization, or they can be used to do software pipelining.