llvm-6502/lib/Analysis
Daniel Berlin 29dbbd73de Move IDF Calculation to a separate file, expose an interface to it.
Summary:
MemorySSA uses this algorithm as well, and this enables us to reuse the code in both places.

There are no actual algorithm or datastructure changes in here, just code movement.

Reviewers: qcolombet, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9118

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235406 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-21 19:13:02 +00:00
..
IPA [Inliner] Don't inline functions with frameescape calls 2015-04-14 20:38:14 +00:00
AliasAnalysis.cpp Add new getModRefInfo API to determine whether an Instruction and a call modify the same memory 2015-04-13 23:25:41 +00:00
AliasAnalysisCounter.cpp Use 'override/final' instead of 'virtual' for overridden methods 2015-04-11 02:11:45 +00:00
AliasAnalysisEvaluator.cpp [CallSite] Make construction from Value* (or Instruction*) explicit. 2015-04-10 14:50:08 +00:00
AliasDebugger.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasSetTracker.cpp [CallSite] Make construction from Value* (or Instruction*) explicit. 2015-04-10 14:50:08 +00:00
Analysis.cpp Divergence analysis for GPU programs 2015-04-10 05:03:50 +00:00
AssumptionCache.cpp
BasicAliasAnalysis.cpp [opaque pointer type] Change GetElementPtrInst::getIndexedType to take the pointee type 2015-03-30 21:41:43 +00:00
BlockFrequencyInfo.cpp Remove superfluous .str() and replace std::string concatenation with Twine. 2015-03-27 17:51:30 +00:00
BlockFrequencyInfoImpl.cpp Remove 4,096 loop scale limitation. 2015-04-01 17:42:27 +00:00
BranchProbabilityInfo.cpp Add range iterators for post order and inverse post order. Use them 2015-04-15 17:41:42 +00:00
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp Remove superfluous .str() and replace std::string concatenation with Twine. 2015-03-27 17:51:30 +00:00
CFLAliasAnalysis.cpp Use 'override/final' instead of 'virtual' for overridden methods 2015-04-11 02:11:45 +00:00
CGSCCPassManager.cpp
CMakeLists.txt Move IDF Calculation to a separate file, expose an interface to it. 2015-04-21 19:13:02 +00:00
CodeMetrics.cpp Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used. 2015-03-23 19:32:43 +00:00
ConstantFolding.cpp [opaque pointer type] API migration for GEP constant factories 2015-04-02 18:55:32 +00:00
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp Fix a memory corruption in Dependency Analysis. 2015-03-10 14:32:02 +00:00
DivergenceAnalysis.cpp Divergence analysis for GPU programs 2015-04-10 05:03:50 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp [opaque pointer type] API migration for GEP constant factories 2015-04-02 18:55:32 +00:00
Interval.cpp
IntervalPartition.cpp
IteratedDominanceFrontier.cpp Move IDF Calculation to a separate file, expose an interface to it. 2015-04-21 19:13:02 +00:00
IVUsers.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
LazyCallGraph.cpp
LazyValueInfo.cpp [ConstantRange] Split makeICmpRegion in two. 2015-03-18 00:41:24 +00:00
LibCallAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LibCallSemantics.cpp Stop calling DwarfEHPrepare from WinEHPrepare 2015-03-12 00:36:20 +00:00
Lint.cpp Fix doxygen comments from r232268 2015-03-16 17:49:03 +00:00
LLVMBuild.txt
Loads.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
LoopAccessAnalysis.cpp [LoopAccesses] Improve debug output 2015-04-17 22:43:10 +00:00
LoopInfo.cpp Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used. 2015-03-23 19:32:43 +00:00
LoopPass.cpp Purge unused includes throughout libSupport. 2015-03-23 18:07:13 +00:00
Makefile
MemDepPrinter.cpp [CallSite] Make construction from Value* (or Instruction*) explicit. 2015-04-10 14:50:08 +00:00
MemDerefPrinter.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
MemoryBuiltins.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
MemoryDependenceAnalysis.cpp Common some code from MemoryDependenceAnalysis that will be used in MemorySSA 2015-04-13 23:20:13 +00:00
ModuleDebugInfoPrinter.cpp DebugInfo: Drop rest of DIDescriptor subclasses 2015-04-21 18:44:06 +00:00
NoAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
PHITransAddr.cpp [opaque pointer type] more gep API migration 2015-03-14 19:53:33 +00:00
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp Change range-based for-loops to be -Wrange-loop-analysis clean. 2015-04-15 01:21:15 +00:00
RegionPrinter.cpp One more -Wrange-loop-analysis cleanup. 2015-04-15 21:40:50 +00:00
ScalarEvolution.cpp Recognize n/1 in the SCEV divide function 2015-04-20 16:03:28 +00:00
ScalarEvolutionAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ScalarEvolutionExpander.cpp [SCEV] Strengthen SCEVExpander::isHighCostExpansion. 2015-04-14 03:20:32 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
SparsePropagation.cpp
StratifiedSets.h
TargetLibraryInfo.cpp [WinEH] Run cleanup handlers when an exception is thrown 2015-03-30 22:58:10 +00:00
TargetTransformInfo.cpp Divergence analysis for GPU programs 2015-04-10 05:03:50 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp Teach TBAA analysis to report errors on cyclic TBAA metadata rather than hanging. 2015-03-13 07:09:33 +00:00
ValueTracking.cpp [CallSite] Make construction from Value* (or Instruction*) explicit. 2015-04-10 14:50:08 +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))

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