llvm-project/polly
Michael Kruse f4e201e09f [Support] Remove NonowningIslPtr. NFC.
NonowningIslPtr<isl_X> was used as types of function parameters when the
function does not consume the isl object, i.e. an __isl_keep parameter.

The alternatives are:

1. IslPtr<isl_X>
   This has additional calls to isl_X_copy and isl_X_free to
   increase/decrease the reference counter even though not needed. The
   caller already owns a reference to the isl object.

2. const IslPtr<isl_X>&
   This does not change the reference counter, but requires an
   additional load to get the pointer to the isl object (instead of just
   passing the pointer itself).
   Moreover, the compiler cannot rely on the constness of the pointer
   and has to reload the pointer every time it writes to memory (unless
   alias analysis such as TBAA says it is not possible).

The isl C++ bindings currently in development do not have an equivalent
to NonowningIslPtr and adding one would make the binding more
complicated and its advantage in performance is small. In order to
simplify the transition to these C++ bindings, remove NonowningIslPtr.
Change every former use of it to alternative 2 mentioned aboce
(const IslPtr<isl_X>&).

llvm-svn: 295998
2017-02-23 17:57:27 +00:00
..
cmake Remove -fvisibility=hidden and FORCE_STATIC. 2016-09-12 18:25:00 +00:00
docs Porting the example illustrating Polly from HTML to reStructuredText 2017-02-10 11:46:57 +00:00
include/polly [Support] Remove NonowningIslPtr. NFC. 2017-02-23 17:57:27 +00:00
lib [Support] Remove NonowningIslPtr. NFC. 2017-02-23 17:57:27 +00:00
test Make optimizations based on pattern matching be enabled by default 2017-02-23 11:44:12 +00:00
tools GPURuntime: ensure compilation with C99 2016-09-11 07:32:50 +00:00
unittests [Support] Remove NonowningIslPtr. NFC. 2017-02-23 17:57:27 +00:00
utils Revise polly-{update|check}-format targets 2015-09-14 16:59:50 +00:00
www Porting the example illustrating Polly from HTML to reStructuredText 2017-02-10 11:46:57 +00:00
.arcconfig Upgrade all the .arcconfigs to https. 2016-07-14 13:15:37 +00:00
.arclint [External] Move lib/JSON to lib/External/JSON. NFC. 2017-02-05 15:26:56 +00:00
.gitattributes
.gitignore Do not track the isl PDF manual in SVN 2017-01-16 11:48:03 +00:00
CMakeLists.txt [Cmake] Bump required cmake version to 3.4.3. 2017-02-20 17:06:31 +00:00
CREDITS.txt Add myself to the credits 2014-08-10 03:37:29 +00:00
LICENSE.txt [External] Move lib/JSON to lib/External/JSON. NFC. 2017-02-05 15:26:56 +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.