llvm-project/polly
Michael Kruse 2dab88e652 [OpTree] Introduce shortcut for computing the def->target mapping. NFCI.
In case the schedule has not changed and the operand tree root uses a
value defined in an ancestor loop, the def-to-target mapping is trivial.
For instance, the SCoP

    for (int i < 0; i < N; i+=1) {
    DefStmt:
      D = ...;
      for (int j < 0; j < N; j+=1) {
    TargetStmt:
        use(D);
      }
    }

has DefStmt-to-TargetStmt mapping of

    { DefStmt[i] -> TargetStmt[i,j] }

This should apply on the majority of def-to-target mappings.
This patch detects this case and directly constructs the expected
mapping. It assumes that the mapping never crosses the loop header
DefStmt is in, which ForwardOpTree does not support at the moment
anyway.

Differential Revision: https://reviews.llvm.org/D47752

llvm-svn: 334134
2018-06-06 21:37:35 +00:00
..
cmake [CMake] Use only keyword-version of target_link_library. NFC. 2018-01-12 16:09:18 +00:00
docs [doc] Overhaul doc on preparing IR for processing by Polly. 2018-04-06 19:24:18 +00:00
include/polly [OpTree] Introduce shortcut for computing the def->target mapping. NFCI. 2018-06-06 21:37:35 +00:00
lib [OpTree] Introduce shortcut for computing the def->target mapping. NFCI. 2018-06-06 21:37:35 +00:00
test [Acc] Followup for r333105: Fix one additional testcase 2018-05-24 10:18:09 +00:00
tools [GPUJIT] Improved temporary file handling. 2017-09-19 10:41:29 +00:00
unittests Remove the last uses of isl::give and isl::take 2018-04-29 00:28:26 +00:00
utils [arc] Remove unittesting from arcconfig 2018-05-15 13:43:42 +00:00
www [Polly] Information about generalized matrix multiplication 2017-09-24 19:00:25 +00:00
.arcconfig [arc] Remove unittesting from arcconfig 2018-05-15 13:43:42 +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] Use only keyword-version of target_link_library. NFC. 2018-01-12 16:09:18 +00:00
CREDITS.txt
LICENSE.txt [External] Move lib/JSON to lib/External/JSON. NFC. 2017-02-05 15:26:56 +00:00
README Test commit 2017-06-28 12:58:44 +00:00

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.