llvm-6502/lib/Analysis
Karthik Bhat 5f9683f54f Fix a crash in Dependency Analysis.
This crash in Dependency analysis is because we assume here that in case of UsefulGEP
both source and destination have the same number of operands which may not be true.
This incorrect assumption results in crash while populating Pairs. Fix the same.

This crash was observed during lnt regression for code such as-
  struct s{
    int A[10][10];
    int C[10][10][10]; 
  } S;
  void dep_constraint_crash_test(int k,int N)  {
     for( int i=0;i<N;i++)
       for( int j=0;j<N;j++)
         S.A[0][0] = S.C[0][0][k];
  }
Review: http://reviews.llvm.org/D8162



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231784 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-10 13:31:03 +00:00
..
IPA removed function names from comments; NFC 2015-03-10 03:48:14 +00:00
AliasAnalysis.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
AliasAnalysisCounter.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasSetTracker.cpp
Analysis.cpp Remove the Forward Control Flow Integrity pass and its dependencies. 2015-02-27 19:03:38 +00:00
AssumptionCache.cpp
BasicAliasAnalysis.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CFLAliasAnalysis.cpp Added ConstantExpr support to CFLAA. 2015-03-10 02:58:15 +00:00
CGSCCPassManager.cpp
CMakeLists.txt Remove the Forward Control Flow Integrity pass and its dependencies. 2015-02-27 19:03:38 +00:00
CodeMetrics.cpp
ConstantFolding.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
CostModel.cpp [multiversion] Thread a function argument through all the callers of the 2015-02-01 12:01:35 +00:00
Delinearization.cpp
DependenceAnalysis.cpp Fix a crash in Dependency Analysis. 2015-03-10 13:31:03 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
Interval.cpp
IntervalPartition.cpp
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 DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
LibCallAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LibCallSemantics.cpp Unify the two EH personality classification routines I wrote 2015-02-14 00:21:02 +00:00
Lint.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +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 DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp MemDepPrinter: Fix some nits introduced in r228596 2015-02-25 23:55:00 +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 DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
ModuleDebugInfoPrinter.cpp DebugInfo: Move new hierarchy into place 2015-03-03 17:24:31 +00:00
NoAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp Avoid calls to dumpPassInfo and RegionBase<Tr>::getNameStr() in RGPassManager if 2015-03-06 16:15:04 +00:00
RegionPrinter.cpp
ScalarEvolution.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
ScalarEvolutionAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ScalarEvolutionExpander.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +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 Make static variables const if possible. Makes them go into a read-only section. 2015-03-08 16:07:39 +00:00
TargetTransformInfo.cpp Do not restrict interleaved unrolling to small loops, depending on the target. 2015-03-06 23:12:04 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ValueTracking.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +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))

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