llvm/lib/Analysis
Cong Hou 40288f7238 [BPI] Replace weights by probabilities in BPI.
This patch removes all weight-related interfaces from BPI and replace
them by probability versions. With this patch, we won't use edge weight
anymore in either IR or MC passes. Edge probabilitiy is a better
representation in terms of CFG update and validation.


Differential revision: http://reviews.llvm.org/D15519 




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@256263 91177308-0d34-0410-b5e6-96231b3b80d8
2015-12-22 18:56:14 +00:00
..
AliasAnalysis.cpp [AliasAnalysis] CatchPad and CatchRet can modify escaped memory 2015-11-17 08:15:14 +00:00
AliasAnalysisEvaluator.cpp Default SetVector to use a DenseSet. 2015-11-18 06:52:18 +00:00
AliasSetTracker.cpp Revert "r251451 - [AliasSetTracker] Use mod/ref information for UnknownInstr" 2015-10-28 22:13:41 +00:00
Analysis.cpp
AssumptionCache.cpp
BasicAliasAnalysis.cpp Fix a typo in BasicAliasAnalysis 2015-11-17 08:15:08 +00:00
BlockFrequencyInfo.cpp Recommit r250345, it was reverted in r250366 to investigate a bot failure. 2015-10-15 14:59:40 +00:00
BlockFrequencyInfoImpl.cpp Recommit r250345, it was reverted in r250366 to investigate a bot failure. 2015-10-15 14:59:40 +00:00
BranchProbabilityInfo.cpp [BPI] Replace weights by probabilities in BPI. 2015-12-22 18:56:14 +00:00
CallGraph.cpp [Analysis/CallGraph] Switch dump() definitions over to LLVM_DUMP_METHOD. 2015-11-23 02:58:42 +00:00
CallGraphSCCPass.cpp
CallPrinter.cpp
CaptureTracking.cpp [IR] Reformulate LLVM's EH funclet IR 2015-12-12 05:38:55 +00:00
CFG.cpp Add some constantness to GetSuccessorNumber(). 2015-11-20 23:02:06 +00:00
CFGPrinter.cpp
CFLAliasAnalysis.cpp
CGSCCPassManager.cpp
CMakeLists.txt Move EH-specific helper functions to a more appropriate place 2015-12-02 23:06:39 +00:00
CodeMetrics.cpp Use all_of to simplify control flow. NFC. 2015-10-24 19:30:37 +00:00
ConstantFolding.cpp
CostModel.cpp Refactor: Simplify boolean conditional return statements in llvm/lib/Analysis 2015-11-05 21:07:12 +00:00
Delinearization.cpp SCEV: Allow simple AddRec * Parameter products in delinearization 2015-10-12 08:02:00 +00:00
DemandedBits.cpp
DependenceAnalysis.cpp [SCEV] Add and use SCEVConstant::getAPInt; NFCI 2015-12-17 20:28:46 +00:00
DivergenceAnalysis.cpp [DivergenceAnalysis] fix a bug in computing influence regions 2015-12-18 21:44:26 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
EHPersonalities.cpp [IR] Remove terminatepad 2015-12-14 18:34:23 +00:00
GlobalsModRef.cpp GlobalsAA: Take advantage of ArgMemOnly, InaccessibleMemOnly and InaccessibleMemOrArgMemOnly attributes 2015-12-18 11:02:52 +00:00
InlineCost.cpp Use updated threshold for indirect call bonus 2015-12-07 21:21:20 +00:00
InstCount.cpp
InstructionSimplify.cpp [IR] Reformulate LLVM's EH funclet IR 2015-12-12 05:38:55 +00:00
Interval.cpp
IntervalPartition.cpp
IteratedDominanceFrontier.cpp
IVUsers.cpp Analysis: Remove implicit ilist iterator conversions 2015-10-10 00:53:03 +00:00
LazyCallGraph.cpp
LazyValueInfo.cpp [LazyValueInfo] Stop inserting overdefined values into ValueCache to 2015-12-11 00:49:47 +00:00
Lint.cpp Revert "Change memcpy/memset/memmove to have dest and source alignments." 2015-11-19 05:56:52 +00:00
LLVMBuild.txt
Loads.cpp Analysis: Remove implicit ilist iterator conversions 2015-10-10 00:53:03 +00:00
LoopAccessAnalysis.cpp [SCEV] Add and use SCEVConstant::getAPInt; NFCI 2015-12-17 20:28:46 +00:00
LoopInfo.cpp [WinEH] Update LCSSA to handle catchswitch with handlers inside and outside a loop 2015-12-18 18:12:35 +00:00
LoopPass.cpp LPM: Make callers of LPM.deleteLoopFromQueue update LoopInfo directly. NFC 2015-12-16 18:40:20 +00:00
Makefile
MemDepPrinter.cpp
MemDerefPrinter.cpp
MemoryBuiltins.cpp [Analysis] Become aware of MSVC's new/delete functions 2015-12-03 22:45:19 +00:00
MemoryDependenceAnalysis.cpp Analysis: Remove implicit ilist iterator conversions 2015-10-10 00:53:03 +00:00
MemoryLocation.cpp
ModuleDebugInfoPrinter.cpp
ObjCARCAliasAnalysis.cpp
ObjCARCAnalysisUtils.cpp
ObjCARCInstKind.cpp Analysis: Remove implicit ilist iterator conversions 2015-10-10 00:53:03 +00:00
OrderedBasicBlock.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp [SCEV] Add and use SCEVConstant::getAPInt; NFCI 2015-12-17 20:28:46 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp [SCEV] Add and use SCEVConstant::getAPInt; NFCI 2015-12-17 20:28:46 +00:00
ScalarEvolutionNormalization.cpp Analysis: Remove implicit ilist iterator conversions 2015-10-10 00:53:03 +00:00
ScopedNoAliasAA.cpp
SparsePropagation.cpp Analysis: Remove implicit ilist iterator conversions 2015-10-10 00:53:03 +00:00
StratifiedSets.h
TargetLibraryInfo.cpp AMDGPU: mark ldexp LibCalls as unavailable 2015-12-15 17:24:15 +00:00
TargetTransformInfo.cpp Revert r243347 "Add TargetTransformInfo::isZExtFree." 2015-11-12 20:51:52 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp [ValueTracking] Properly handle non-sized types in isAligned function. 2015-12-21 20:38:18 +00:00
VectorUtils.cpp [SCEV] Add and use SCEVConstant::getAPInt; NFCI 2015-12-17 20:28:46 +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))

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