llvm-6502/lib/Analysis
Philip Reames ce0e12f0b4 [REFACTOR] Push logic from MemDepPrinter into getNonLocalPointerDependency
Previously, MemDepPrinter handled volatile and unordered accesses without involving MemoryDependencyAnalysis.  By making a slight tweak to the documented interface - which is respected by both callers - we can move this responsibility to MDA for the benefit of any future callers.  This is basically just cleanup.

In the future, we may decide to extend MDA's non local dependency analysis to return useful results for ordered or volatile loads.  I believe (but have not really checked in detail) that local dependency analyis does get useful results for ordered, but not volatile, loads.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225483 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-09 00:26:45 +00:00
..
IPA [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
AliasAnalysis.cpp Sink store based on alias analysis 2014-12-15 14:09:53 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp AliasSet: Simplify mergeSetIn 2014-11-19 19:36:18 +00:00
Analysis.cpp
AssumptionCache.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
BasicAliasAnalysis.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp BFI: Saturate when combining edges to a successor 2014-12-05 19:13:42 +00:00
BranchProbabilityInfo.cpp IR: Split Metadata from Value 2014-12-09 18:38:53 +00:00
CaptureTracking.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
CFG.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
CFGPrinter.cpp
CFLAliasAnalysis.cpp
CGSCCPassManager.cpp [PM] Fix a pretty nasty bug where the new pass manager would invalidate 2015-01-07 01:58:35 +00:00
CMakeLists.txt [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
CodeMetrics.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ConstantFolding.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
FunctionTargetTransformInfo.cpp
InstCount.cpp
InstructionSimplify.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
JumpInstrTableInfo.cpp
LazyCallGraph.cpp [PM] Switch the new pass manager to use a reference-based API for IR 2015-01-05 02:47:05 +00:00
LazyValueInfo.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
LLVMBuild.txt
Loads.cpp Revert r220349 to re-instate r220277 with a fix for PR21330 -- quite 2014-11-25 08:20:27 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp [REFACTOR] Push logic from MemDepPrinter into getNonLocalPointerDependency 2015-01-09 00:26:45 +00:00
MemoryBuiltins.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
MemoryDependenceAnalysis.cpp [REFACTOR] Push logic from MemDepPrinter into getNonLocalPointerDependency 2015-01-09 00:26:45 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
PostDominators.cpp
PtrUseVisitor.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
TargetTransformInfo.cpp Remove empty statement. No functionality change. 2015-01-08 00:47:03 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp IR: Split Metadata from Value 2014-12-09 18:38:53 +00:00
ValueTracking.cpp Analysis: Reformulate WillNotOverflowUnsignedAdd for reusability 2015-01-07 00:39:50 +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))

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