maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/llvm/lib/Analysis
History
Arnold Schwaighofer 1a444489e9 PR15967 Fix in basicaa for faulty returning no alias. 
This commit consist of two parts.
The first part fix the PR15967. The wrong conclusion was made when the MaxLookup
limit was reached. The fix introduce a out parameter (MaxLookupReached) to
DecomposeGEPExpression that the function aliasGEP can act upon.
The second part is introducing the constant MaxLookupSearchDepth to make sure
that DecomposeGEPExpression and GetUnderlyingObject use the same search depth.
This is a small cleanup to clarify the original algorithm.

Patch by Karl-Johan Karlsson!

llvm-svn: 204859
 		2014-03-26 21:30:19 +00:00
..
IPA Consistent use of the noduplicate attribute. 2014-03-17 16:19:07 +00:00
AliasAnalysis.cpp IR: add a second ordering operand to cmpxhg for failure 2014-03-11 10:48:52 +00:00
AliasAnalysisCounter.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
AliasAnalysisEvaluator.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
AliasDebugger.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
AliasSetTracker.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
Analysis.cpp [cleanup] Re-sort all the includes with utils/sort_includes.py. 2014-03-04 10:07:28 +00:00
BasicAliasAnalysis.cpp PR15967 Fix in basicaa for faulty returning no alias. 2014-03-26 21:30:19 +00:00
BlockFrequencyInfo.cpp blockfreq: Implement Pass::releaseMemory() 2014-03-25 18:01:38 +00:00
BranchProbabilityInfo.cpp [Modules] Move CFG.h to the IR library as it defines graph traits over 2014-03-04 11:45:46 +00:00
CFG.cpp Simplify loop that worked around bugs in old GCC/Xcode. 2014-03-25 09:06:18 +00:00
CFGPrinter.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
CMakeLists.txt [PM] Add a new "lazy" call graph analysis pass for the new pass manager. 2014-02-06 04:37:03 +00:00
CaptureTracking.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
CodeMetrics.cpp Consistent use of the noduplicate attribute. 2014-03-17 16:19:07 +00:00
ConstantFolding.cpp Allow constant folding of ceil function whenever feasible 2014-03-24 04:36:06 +00:00
CostModel.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
Delinearization.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
DependenceAnalysis.cpp [Modules] Move InstIterator out of the Support library, where it had no 2014-03-04 10:30:26 +00:00
DomPrinter.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
DominanceFrontier.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
IVUsers.cpp PR17473: 2014-03-12 21:31:05 +00:00
InstCount.cpp [Layering] Move InstVisitor.h into the IR library as it is pretty 2014-03-06 03:23:41 +00:00
InstructionSimplify.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
Interval.cpp [Modules] Move CFG.h to the IR library as it defines graph traits over 2014-03-04 11:45:46 +00:00
IntervalPartition.cpp
…
LLVMBuild.txt LLVMBuild: Introduce a common section which currently has a list of the 2011-12-12 22:45:54 +00:00
LazyCallGraph.cpp [LCG] Ran clang-format over this too and it pointed out some fixes. 2014-03-10 02:14:14 +00:00
LazyValueInfo.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
LibCallAliasAnalysis.cpp Move all of the header files which are involved in modelling the LLVM IR 2013-01-02 11:36:10 +00:00
LibCallSemantics.cpp Move all of the header files which are involved in modelling the LLVM IR 2013-01-02 11:36:10 +00:00
Lint.cpp Teach lint about address spaces 2014-03-06 17:33:55 +00:00
Loads.cpp Change GetPointerBaseWithConstantOffset's DataLayout argument from a 2013-01-31 02:00:45 +00:00
LoopInfo.cpp Consistent use of the noduplicate attribute. 2014-03-17 16:19:07 +00:00
LoopPass.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
Makefile
…
MemDepPrinter.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
MemoryBuiltins.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
MemoryDependenceAnalysis.cpp Replace OwningPtr<T> with std::unique_ptr<T>. 2014-03-06 05:51:42 +00:00
ModuleDebugInfoPrinter.cpp [C++11] Change DebugInfoFinder to use range-based loops 2014-03-18 09:41:07 +00:00
NoAliasAnalysis.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
PHITransAddr.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
PostDominators.cpp [Modules] Move CFG.h to the IR library as it defines graph traits over 2014-03-04 11:45:46 +00:00
PtrUseVisitor.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
README.txt
…
RegionInfo.cpp [C++11] Add a basic block range view for RegionInfo 2014-03-03 13:00:39 +00:00
RegionPass.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
RegionPrinter.cpp [C++11] Add a basic block range view for RegionInfo 2014-03-03 13:00:39 +00:00
ScalarEvolution.cpp ScalarEvolution: Compute exit counts for loops with a power-of-2 step. 2014-03-25 16:25:12 +00:00
ScalarEvolutionAliasAnalysis.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
ScalarEvolutionExpander.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
ScalarEvolutionNormalization.cpp Add stride normalization to SCEV Normalize/Denormalize transformation. 2014-03-18 17:34:03 +00:00
SparsePropagation.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
TargetTransformInfo.cpp [Constant Hoisting] Make the constant materialization cost operand dependent 2014-03-21 06:04:45 +00:00
Trace.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
TypeBasedAliasAnalysis.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
ValueTracking.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00

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))

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