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IPA
IPA
 
 
AliasAnalysis.cpp
AliasAnalysis.cpp
 
 
AliasAnalysisCounter.cpp
AliasAnalysisCounter.cpp
 
 
AliasAnalysisEvaluator.cpp
AliasAnalysisEvaluator.cpp
 
 
AliasDebugger.cpp
AliasDebugger.cpp
 
 
AliasSetTracker.cpp
AliasSetTracker.cpp
 
 
Analysis.cpp
Analysis.cpp
 
 
BasicAliasAnalysis.cpp
BasicAliasAnalysis.cpp
 
 
BlockFrequencyInfo.cpp
BlockFrequencyInfo.cpp
 
 
BranchProbabilityInfo.cpp
BranchProbabilityInfo.cpp
 
 
CFG.cpp
CFG.cpp
 
 
CFGPrinter.cpp
CFGPrinter.cpp
 
 
CMakeLists.txt
CMakeLists.txt
 
 
CaptureTracking.cpp
CaptureTracking.cpp
 
 
CodeMetrics.cpp
CodeMetrics.cpp
 
 
ConstantFolding.cpp
ConstantFolding.cpp
 
 
CostModel.cpp
CostModel.cpp
 
 
Delinearization.cpp
Delinearization.cpp
 
 
DependenceAnalysis.cpp
DependenceAnalysis.cpp
 
 
DomPrinter.cpp
DomPrinter.cpp
 
 
DominanceFrontier.cpp
DominanceFrontier.cpp
 
 
IVUsers.cpp
IVUsers.cpp
 
 
InstCount.cpp
InstCount.cpp
 
 
InstructionSimplify.cpp
InstructionSimplify.cpp
 
 
Interval.cpp
Interval.cpp
 
 
IntervalPartition.cpp
IntervalPartition.cpp
 
 
LLVMBuild.txt
LLVMBuild.txt
 
 
LazyValueInfo.cpp
LazyValueInfo.cpp
 
 
LibCallAliasAnalysis.cpp
LibCallAliasAnalysis.cpp
 
 
LibCallSemantics.cpp
LibCallSemantics.cpp
 
 
Lint.cpp
Lint.cpp
 
 
Loads.cpp
Loads.cpp
 
 
LoopInfo.cpp
LoopInfo.cpp
 
 
LoopPass.cpp
LoopPass.cpp
 
 
Makefile
Makefile
 
 
MemDepPrinter.cpp
MemDepPrinter.cpp
 
 
MemoryBuiltins.cpp
MemoryBuiltins.cpp
 
 
MemoryDependenceAnalysis.cpp
MemoryDependenceAnalysis.cpp
 
 
ModuleDebugInfoPrinter.cpp
ModuleDebugInfoPrinter.cpp
 
 
NoAliasAnalysis.cpp
NoAliasAnalysis.cpp
 
 
PHITransAddr.cpp
PHITransAddr.cpp
 
 
PostDominators.cpp
PostDominators.cpp
 
 
PtrUseVisitor.cpp
PtrUseVisitor.cpp
 
 
README.txt
README.txt
 
 
RegionInfo.cpp
RegionInfo.cpp
 
 
RegionPass.cpp
RegionPass.cpp
 
 
RegionPrinter.cpp
RegionPrinter.cpp
 
 
ScalarEvolution.cpp
ScalarEvolution.cpp
 
 
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionAliasAnalysis.cpp
 
 
ScalarEvolutionExpander.cpp
ScalarEvolutionExpander.cpp
 
 
ScalarEvolutionNormalization.cpp
ScalarEvolutionNormalization.cpp
 
 
SparsePropagation.cpp
SparsePropagation.cpp
 
 
TargetTransformInfo.cpp
TargetTransformInfo.cpp
 
 
Trace.cpp
Trace.cpp
 
 
TypeBasedAliasAnalysis.cpp
TypeBasedAliasAnalysis.cpp
 
 
ValueTracking.cpp
ValueTracking.cpp
 
 

README.txt

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))

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