1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-21 20:12:56 +02:00
llvm-mirror/lib/Transforms/Vectorize
Silviu Baranga ab8c77a47d [SCEV][LV] Add SCEV Predicates and use them to re-implement stride versioning
Summary:
SCEV Predicates represent conditions that typically cannot be derived from
static analysis, but can be used to reduce SCEV expressions to forms which are
usable for different optimizers.

ScalarEvolution now has the rewriteUsingPredicate method which can simplify a
SCEV expression using a SCEVPredicateSet. The normal workflow of a pass using
SCEVPredicates would be to hold a SCEVPredicateSet and every time assumptions
need to be made a new SCEV Predicate would be created and added to the set.
Each time after calling getSCEV, the user will call the rewriteUsingPredicate
method.

We add two types of predicates
SCEVPredicateSet - implements a set of predicates
SCEVEqualPredicate - tests for equality between two SCEV expressions

We use the SCEVEqualPredicate to re-implement stride versioning. Every time we
version a stride, we will add a SCEVEqualPredicate to the context.
Instead of adding specific stride checks, LoopVectorize now adds a more
generic SCEV check.

We only need to add support for this in the LoopVectorizer since this is the
only pass that will do stride versioning.

Reviewers: mzolotukhin, anemet, hfinkel, sanjoy

Subscribers: sanjoy, hfinkel, rengolin, jmolloy, llvm-commits

Differential Revision: http://reviews.llvm.org/D13595

llvm-svn: 251800
2015-11-02 14:41:02 +00:00
..
BBVectorize.cpp Vectorize: Remove implicit ilist iterator conversions, NFC 2015-10-19 22:06:09 +00:00
CMakeLists.txt Use ADDITIONAL_HEADER_DIRS in all LLVM CMake projects. 2015-02-11 03:28:02 +00:00
LLVMBuild.txt Update libdeps since TLI was moved from Target to Analysis in r226078. 2015-01-15 05:21:00 +00:00
LoopVectorize.cpp [SCEV][LV] Add SCEV Predicates and use them to re-implement stride versioning 2015-11-02 14:41:02 +00:00
Makefile
SLPVectorizer.cpp [SLP] Be more aggressive about reduction width selection. 2015-10-27 17:59:03 +00:00
Vectorize.cpp [PM] Remove the old 'PassManager.h' header file at the top level of 2015-02-13 10:01:29 +00:00