llvm/lib/Analysis
Brendon Cahoon 3188534401 [DependenceAnalysis] Check if result of getConstantPart is null
A seg-fault occurs due to a reference of a null pointer, which is
the value returned by getConstantPart. This function returns
null if the constant part is not found. The code that calls this
function needs to check for the null return value.

Differential Revision: http://reviews.llvm.org/D18718


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265319 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-04 18:13:18 +00:00
..
AliasAnalysis.cpp [PM] Implement the final conclusion as to how the analysis IDs should 2016-03-11 10:22:49 +00:00
AliasAnalysisEvaluator.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
AliasSetTracker.cpp [AliasSetTracker] Do not strip pointer casts when processing MemSetInst 2016-03-14 18:34:29 +00:00
Analysis.cpp [CG] Actually hoist up the generic CallGraphPrinter pass from a weird 2016-03-10 11:08:44 +00:00
AssumptionCache.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
BasicAliasAnalysis.cpp [AA] Make BasicAA just require domtree. 2016-03-11 13:53:18 +00:00
BlockFrequencyInfo.cpp Add getBlockProfileCount method to BlockFrequencyInfo 2016-03-23 18:18:26 +00:00
BlockFrequencyInfoImpl.cpp Fix Clang-tidy readability-redundant-control-flow warnings; other minor fixes. 2016-02-02 18:20:45 +00:00
BranchProbabilityInfo.cpp [BPI] Fix two potential divide-by-zero operations that are introduced in r256263. 2015-12-22 23:45:55 +00:00
CallGraph.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
CallGraphSCCPass.cpp Recommit r256952 "Filtering IR printing for print-after-all/print-before-all" 2016-01-06 22:55:03 +00:00
CallPrinter.cpp [CG] Rename the DOT printing pass to actually reference "DOT". 2016-03-10 11:04:40 +00:00
CaptureTracking.cpp [CaptureTracking] Support atomicrmw and cmpxchg 2016-02-18 19:23:27 +00:00
CFG.cpp Avoid overly large SmallPtrSet/SmallSet 2016-01-30 01:24:31 +00:00
CFGPrinter.cpp
CFLAliasAnalysis.cpp Rename DenseMap::resize() into DenseMap::reserve() (NFC) 2016-03-22 07:20:00 +00:00
CGSCCPassManager.cpp [PM] Implement the final conclusion as to how the analysis IDs should 2016-03-11 10:22:49 +00:00
CMakeLists.txt PM: Implement a basic loop pass manager 2016-02-25 07:23:08 +00:00
CodeMetrics.cpp use range-based for loop; NFCI 2016-03-08 20:53:48 +00:00
ConstantFolding.cpp Fix Clang-tidy modernize-deprecated-headers warnings in some files; other minor fixes. 2016-03-28 17:40:08 +00:00
CostModel.cpp Implemented cost model for masked gather and scatter operations 2015-12-28 20:10:59 +00:00
Delinearization.cpp
DemandedBits.cpp [DemandedBits] Revert r249687 due to PR26071 2016-02-03 15:05:06 +00:00
DependenceAnalysis.cpp [DependenceAnalysis] Check if result of getConstantPart is null 2016-04-04 18:13:18 +00:00
DivergenceAnalysis.cpp Introduce analysis pass to compute PostDominators in the new pass manager. NFC 2016-02-25 17:54:07 +00:00
DominanceFrontier.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
DomPrinter.cpp Introduce analysis pass to compute PostDominators in the new pass manager. NFC 2016-02-25 17:54:07 +00:00
EHPersonalities.cpp Add Rust's personality function to the list of known personality functions 2016-03-15 20:35:45 +00:00
GlobalsModRef.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
InlineCost.cpp Revert revisions 262636, 262643, 262679, and 262682. 2016-03-08 00:36:35 +00:00
InstCount.cpp
InstructionSimplify.cpp [InstSimplify] Restore fsub 0.0, (fsub 0.0, X) ==> X optzn 2016-02-29 12:18:25 +00:00
Interval.cpp
IntervalPartition.cpp
IteratedDominanceFrontier.cpp
IVUsers.cpp Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment. 2016-01-29 20:50:44 +00:00
LazyCallGraph.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
LazyValueInfo.cpp [LVI] Fix a bug which prevented use of !range metadata within a query 2016-03-04 22:27:39 +00:00
Lint.cpp [opaque pointer types] [NFC] FindAvailableLoadedValue: take LoadInst instead of just the pointer. 2016-01-22 01:51:51 +00:00
LLVMBuild.txt
Loads.cpp NFC. Move isDereferenceable to Loads.h/cpp 2016-02-24 12:49:04 +00:00
LoopAccessAnalysis.cpp [LAA] Formatting fix in previous change 2016-03-24 05:15:24 +00:00
LoopInfo.cpp IR: Reserve an MDKind for !llvm.loop; NFC 2016-03-25 00:35:38 +00:00
LoopPass.cpp LoopInfo: Simplify ownership of Loop objects 2016-01-08 19:08:53 +00:00
LoopPassManager.cpp [PM] Implement the final conclusion as to how the analysis IDs should 2016-03-11 10:22:49 +00:00
LoopUnrollAnalyzer.cpp [LoopUnrollAnalyzer] Check that we're using SCEV for the same loop we're simulating. 2016-02-26 02:57:05 +00:00
MemDepPrinter.cpp [PM] Port memdep to the new pass manager. 2016-03-10 00:55:30 +00:00
MemDerefPrinter.cpp NFC. Move isDereferenceable to Loads.h/cpp 2016-02-24 12:49:04 +00:00
MemoryBuiltins.cpp [MemoryBuiltins] Fix an issue with hasNoAliasAttr 2016-02-09 21:54:18 +00:00
MemoryDependenceAnalysis.cpp Fix "warning: variabl 'XX’ set but not used" in release build (variable used in assertion, NFC) 2016-04-02 05:34:19 +00:00
MemoryLocation.cpp
ModuleDebugInfoPrinter.cpp
ObjCARCAliasAnalysis.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
ObjCARCAnalysisUtils.cpp
ObjCARCInstKind.cpp Add support for objc_unsafeClaimAutoreleasedReturnValue to the 2016-01-27 19:05:08 +00:00
OrderedBasicBlock.cpp
PHITransAddr.cpp Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment. 2016-01-29 20:50:44 +00:00
PostDominators.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp [SCEV] Track NoWrap properties using MatchBinaryOp, NFC 2016-03-31 05:14:26 +00:00
ScalarEvolutionAliasAnalysis.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
ScalarEvolutionExpander.cpp [IndVars] Fix PR26974: make sure replaceCongruentIVs doesn't break LCSSA 2016-03-21 12:44:29 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
SparsePropagation.cpp
StratifiedSets.h
TargetLibraryInfo.cpp [NVPTX] Infer __nvvm_reflect as nounwind, readnone 2016-03-31 21:29:57 +00:00
TargetTransformInfo.cpp [LoopDataPrefetch] Add TTI to limit the number of iterations to prefetch ahead 2016-03-18 00:27:43 +00:00
Trace.cpp Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment. 2016-01-29 20:50:44 +00:00
TypeBasedAliasAnalysis.cpp [PM] Make the AnalysisManager parameter to run methods a reference. 2016-03-11 11:05:24 +00:00
ValueTracking.cpp Mark some FP intrinsics as safe to speculatively execute 2016-04-03 12:30:46 +00:00
VectorUtils.cpp [VectorUtils] Don't try and truncate PHIs to a smaller bitwidth 2016-03-30 10:11:43 +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))

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