llvm-6502/lib/Analysis
Michael Kuperstein a098c770e1 [ValueTracking] Move GlobalAlias handling to be after the max depth check in computeKnownBits()
GlobalAlias handling used to be after GlobalValue handling, which meant it was, in practice, dead code. r220165 moved GlobalAlias handling to be before GlobalValue handling, but also moved it to be before the max depth check, causing an assert due to a recursion depth limit violation. 

This moves GlobalAlias handling forward to where it's safe, and changes the GlobalValue handling to only look at GlobalObjects.

Differential Revision: http://reviews.llvm.org/D6758

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224765 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-23 11:33:41 +00:00
..
IPA Remove the unused FindUsedTypes pass. 2014-11-24 20:53:26 +00:00
AliasAnalysis.cpp Sink store based on alias analysis 2014-12-15 14:09:53 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp AliasSet: Simplify mergeSetIn 2014-11-19 19:36:18 +00:00
Analysis.cpp Revert "Don't make assumptions about the name of private global variables." 2014-11-15 02:03:53 +00:00
AssumptionTracker.cpp Clean up assume intrinsic pattern matching, no need to check that the argument is a value. 2014-10-25 18:09:01 +00:00
BasicAliasAnalysis.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp BFI: Saturate when combining edges to a successor 2014-12-05 19:13:42 +00:00
BranchProbabilityInfo.cpp IR: Split Metadata from Value 2014-12-09 18:38:53 +00:00
CaptureTracking.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
CFG.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
CFGPrinter.cpp Modernize raw_fd_ostream's constructor a bit. 2014-08-25 18:16:47 +00:00
CFLAliasAnalysis.cpp Remove redundant virtual on overriden functions. 2014-11-14 19:06:36 +00:00
CGSCCPassManager.cpp
CMakeLists.txt Add file to CMake build as well. 2014-09-18 00:39:20 +00:00
CodeMetrics.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
ConstantFolding.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp [DependenceAnalysis] Allow subscripts of different types 2014-11-16 16:52:44 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
FunctionTargetTransformInfo.cpp Add a new pass FunctionTargetTransformInfo. This pass serves as a 2014-09-18 00:34:14 +00:00
InstCount.cpp
InstructionSimplify.cpp InstSimplify: Don't bother if getScalarSizeInBits returns zero 2014-12-20 04:45:33 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
JumpInstrTableInfo.cpp Add Forward Control-Flow Integrity. 2014-11-11 21:08:02 +00:00
LazyCallGraph.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
LazyValueInfo.cpp LazyValueInfo: Actually re-visit partially solved block-values in solveBlockValue() 2014-11-25 17:23:05 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp remove function names from comments; NFC 2014-10-21 18:26:57 +00:00
Lint.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
LLVMBuild.txt
Loads.cpp Revert r220349 to re-instate r220277 with a fix for PR21330 -- quite 2014-11-25 08:20:27 +00:00
LoopInfo.cpp Revert "IR: MDNode => Value" 2014-11-11 21:30:22 +00:00
LoopPass.cpp Fix assertion in LICM doFinalization() 2014-09-24 16:48:31 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
MemoryDependenceAnalysis.cpp Remove redundant assignment. 2014-12-19 11:29:34 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp Simplify code. No functionality change. 2014-10-05 12:21:57 +00:00
PHITransAddr.cpp Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
PostDominators.cpp
PtrUseVisitor.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp Teach ScalarEvolution to exploit min and max expressions when proving 2014-12-15 22:50:15 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
ScalarEvolutionNormalization.cpp Fix typos in comments, NFC 2014-08-29 21:53:01 +00:00
ScopedNoAliasAA.cpp Revert "IR: MDNode => Value" 2014-11-11 21:30:22 +00:00
SparsePropagation.cpp
StratifiedSets.h Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
TargetTransformInfo.cpp Loop Vectorizer minor changes in the code - 2014-12-14 09:43:50 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp IR: Split Metadata from Value 2014-12-09 18:38:53 +00:00
ValueTracking.cpp [ValueTracking] Move GlobalAlias handling to be after the max depth check in computeKnownBits() 2014-12-23 11:33:41 +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))

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