llvm/lib/Analysis
Arnold Schwaighofer 2b475922e6 Optimistically analyse Phi cycles
Analyse Phis under the starting assumption that they are NoAlias. Recursively
look at their inputs.
If they MayAlias/MustAlias there must be an input that makes them so.

Addresses bug 14351.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169788 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-10 23:02:41 +00:00
..
IPA Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
AliasAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
AliasAnalysisCounter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
AliasAnalysisEvaluator.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
AliasDebugger.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
AliasSetTracker.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
Analysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
BasicAliasAnalysis.cpp Optimistically analyse Phi cycles 2012-12-10 23:02:41 +00:00
BlockFrequencyInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
BranchProbabilityInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
CaptureTracking.cpp Give CaptureTracker::shouldExplore a base implementation. Most users want to do 2012-10-08 22:12:48 +00:00
CFGPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
CMakeLists.txt Add a new visitor for walking the uses of a pointer value. 2012-12-10 08:28:39 +00:00
CodeMetrics.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ConstantFolding.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
CostModel.cpp constify the cost API 2012-12-03 22:47:12 +00:00
DbgInfoPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
DependenceAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
DominanceFrontier.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
DomPrinter.cpp remove the blank line from previous ci. 2012-02-04 03:18:47 +00:00
InlineCost.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
InstCount.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
InstructionSimplify.cpp Reorganize FastMathFlags to be a wrapper around unsigned, and streamline some interfaces. 2012-12-09 21:12:04 +00:00
Interval.cpp Revert 'Fix a typo 'iff' => 'if''. iff is an abreviation of if and only if. See: http://en.wikipedia.org/wiki/If_and_only_if Commit 164767 2012-09-27 10:14:43 +00:00
IntervalPartition.cpp Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
IVUsers.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
LazyValueInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
LibCallAliasAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
LibCallSemantics.cpp Thread const correctness through a bunch of AliasAnalysis interfaces and 2010-08-03 21:48:53 +00:00
Lint.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
LLVMBuild.txt LLVMBuild: Introduce a common section which currently has a list of the 2011-12-12 22:45:54 +00:00
Loads.cpp Move TargetData to DataLayout. 2012-10-08 16:38:25 +00:00
LoopInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
LoopPass.cpp Enable the new LoopInfo algorithm by default. 2012-06-26 04:11:38 +00:00
Makefile make -fno-rtti the default unless a directory builds with REQUIRES_RTTI. 2010-01-24 20:43:08 +00:00
MemDepPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
MemoryBuiltins.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
MemoryDependenceAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ModuleDebugInfoPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
NoAliasAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PathNumbering.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PathProfileInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PathProfileVerifier.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PHITransAddr.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PostDominators.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileDataLoader.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileDataLoaderPass.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileEstimatorPass.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileInfoLoader.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileInfoLoaderPass.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ProfileVerifierPass.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
PtrUseVisitor.cpp Add a new visitor for walking the uses of a pointer value. 2012-12-10 08:28:39 +00:00
README.txt When checking whether the special handling for an addrec increment which 2010-04-26 21:46:36 +00:00
RegionInfo.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
RegionPass.cpp Remove the the block_node_iterator of Region, replace it by the block_iterator. 2012-08-27 13:49:24 +00:00
RegionPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ScalarEvolution.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ScalarEvolutionAliasAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ScalarEvolutionExpander.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ScalarEvolutionNormalization.cpp More dead code removal (using -Wunreachable-code) 2012-01-20 21:51:11 +00:00
SparsePropagation.cpp Taken into account Duncan's comments for r149481 dated by 2nd Feb 2012: 2012-03-08 07:06:20 +00:00
Trace.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
TypeBasedAliasAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ValueTracking.cpp Add support to ValueTracking for determining that a pointer is non-null 2012-12-07 02:08:58 +00:00

Analysis Opportunities:

//===---------------------------------------------------------------------===//

In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the
ScalarEvolution expression for %r is this:

  {1,+,3,+,2}<loop>

Outside the loop, this could be evaluated simply as (%n * %n), however
ScalarEvolution currently evaluates it as

  (-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n))

In addition to being much more complicated, it involves i65 arithmetic,
which is very inefficient when expanded into code.

//===---------------------------------------------------------------------===//

In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll,

ScalarEvolution is forming this expression:

((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32)))

This could be folded to

(-1 * (trunc i64 undef to i32))

//===---------------------------------------------------------------------===//