hanchenye-llvm-project/llvm/lib/Analysis
Hal Finkel b035621720 Move the CapturesBefore tracker from AA into CaptureTracking
There were two generally-useful CaptureTracker classes defined in LLVM: the
simple tracker defined in CaptureTracking (and made available via the
PointerMayBeCaptured utility function), and the CapturesBefore tracker
available only inside of AA. This change moves the CapturesBefore tracker into
CaptureTracking, generalizes it slightly (by adding a ReturnCaptures
parameter), and makes it generally available via a PointerMayBeCapturedBefore
utility function.

This logic will be needed, for example, to perform noalias function parameter
attribute inference.

No functionality change intended.

llvm-svn: 213519
2014-07-21 13:15:48 +00:00
..
IPA Remove uses of the redundant ".reset(nullptr)" of unique_ptr, in favor of ".reset()" 2014-07-19 01:05:11 +00:00
AliasAnalysis.cpp Move the CapturesBefore tracker from AA into CaptureTracking 2014-07-21 13:15:48 +00:00
AliasAnalysisCounter.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
Analysis.cpp Templatify RegionInfo so it works on MachineBasicBlocks 2014-07-19 18:29:29 +00:00
BasicAliasAnalysis.cpp Move isIdentifiedFunctionLocal from BasicAA to AA 2014-07-21 12:27:23 +00:00
BlockFrequencyInfo.cpp Revert "Introduce a string_ostream string builder facilty" 2014-06-26 22:52:05 +00:00
BlockFrequencyInfoImpl.cpp BFI: Add constructor for Weight 2014-07-12 00:26:00 +00:00
BranchProbabilityInfo.cpp Remove braces around single-statement block and rangify outer loop. 2014-07-20 09:20:47 +00:00
CFG.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
CFGPrinter.cpp Clean up language and grammar. 2014-05-20 17:11:11 +00:00
CGSCCPassManager.cpp [PM] Add a new-PM-style CGSCC pass manager using the newly added 2014-04-21 11:12:00 +00:00
CMakeLists.txt Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute. 2014-06-05 19:29:43 +00:00
CaptureTracking.cpp Move the CapturesBefore tracker from AA into CaptureTracking 2014-07-21 13:15:48 +00:00
CodeMetrics.cpp
ConstantFolding.cpp Look through addrspacecast in IsConstantOffsetFromGlobal 2014-07-14 22:39:26 +00:00
CostModel.cpp [CostModel][x86] Improved cost model for alternate shuffles. 2014-07-03 22:24:18 +00:00
Delinearization.cpp remove BasePointer before delinearizing 2014-05-27 22:41:51 +00:00
DependenceAnalysis.cpp remove BasePointer before delinearizing 2014-05-27 22:41:51 +00:00
DomPrinter.cpp
DominanceFrontier.cpp Templatify DominanceFrontier. 2014-07-12 21:59:52 +00:00
IVUsers.cpp Add back functionality removed in r210497. 2014-06-21 02:43:02 +00:00
InstCount.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
InstructionSimplify.cpp Rectify r213231. Use proper version of 'ComputeNumSignBits'. 2014-07-17 19:07:00 +00:00
Interval.cpp [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges. 2014-07-20 09:10:11 +00:00
IntervalPartition.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
JumpInstrTableInfo.cpp Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute. 2014-06-05 19:29:43 +00:00
LLVMBuild.txt
LazyCallGraph.cpp Fix typos 2014-05-15 01:52:21 +00:00
LazyValueInfo.cpp [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges. 2014-07-20 09:10:11 +00:00
LibCallAliasAnalysis.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
LibCallSemantics.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
Lint.cpp Revert "Introduce a string_ostream string builder facilty" 2014-06-26 22:52:05 +00:00
Loads.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
LoopInfo.cpp [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges. 2014-07-20 09:10:11 +00:00
LoopPass.cpp Add back functionality removed in r210497. 2014-06-21 02:43:02 +00:00
Makefile
MemDepPrinter.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
MemoryBuiltins.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
MemoryDependenceAnalysis.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
ModuleDebugInfoPrinter.cpp [C++11] Change DebugInfoFinder to use range-based loops 2014-03-18 09:41:07 +00:00
NoAliasAnalysis.cpp Improve BasicAA CS-CS queries (redux) 2014-07-17 01:28:25 +00:00
PHITransAddr.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
PostDominators.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp Fix msc17 build. RegionInfo::RegionInfo::recalculate() doesn't make sense. 2014-07-20 03:57:51 +00:00
RegionPass.cpp Templatify RegionInfo so it works on MachineBasicBlocks 2014-07-19 18:29:29 +00:00
RegionPrinter.cpp Templatify RegionInfo so it works on MachineBasicBlocks 2014-07-19 18:29:29 +00:00
ScalarEvolution.cpp [C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges. 2014-07-20 09:10:11 +00:00
ScalarEvolutionAliasAnalysis.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
ScalarEvolutionExpander.cpp SCEVExpander: Fold constant PHIs harder. The logic below only understands proper IVs. 2014-06-21 11:47:18 +00:00
ScalarEvolutionNormalization.cpp test check-in: added missing parenthesis in comment 2014-05-28 19:03:33 +00:00
SparsePropagation.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
TargetTransformInfo.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp [TBAA] Fix handling of mixed TBAA (path-aware and non-path-aware TBAA). 2014-05-03 22:32:52 +00:00
ValueTracking.cpp Add a dereferenceable attribute 2014-07-18 15:51:28 +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))

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