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Nikita Popov ed3ca9272f [ValueTracking] Known bits support for unsigned saturating add/sub 
We have two sources of known bits:

1. For adds leading ones of either operand are preserved. For sub
leading zeros of LHS and leading ones of RHS become leading zeros in
the result.

2. The saturating math is a select between add/sub and an all-ones/
zero value. As such we can carry out the add/sub known bits
calculation, and only preseve the known one/zero bits respectively.

Differential Revision: https://reviews.llvm.org/D58329

llvm-svn: 355223
2019-03-01 20:07:04 +00:00
..
AliasAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
AliasAnalysisEvaluator.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
AliasAnalysisSummary.cpp
Move CFLGraph and the AA summary code over to the new CallBase
2019-02-11 09:25:41 +00:00
AliasAnalysisSummary.h
Move CFLGraph and the AA summary code over to the new CallBase
2019-02-11 09:25:41 +00:00
AliasSetTracker.cpp
[LICM/MSSA] Add promotion to scalars by building an AliasSetTracker with MemorySSA.
2019-02-06 20:25:17 +00:00
Analysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
AssumptionCache.cpp
[CodeExtractor] Update function's assumption cache after extracting blocks from it
2019-02-08 06:55:18 +00:00
BasicAliasAnalysis.cpp
[BasicAA] Cache nonEscapingLocalObjects for alias() calls.
2019-02-05 23:52:08 +00:00
BlockFrequencyInfo.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
BlockFrequencyInfoImpl.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
BranchProbabilityInfo.cpp
[BPI] Look through bitcasts in calcZeroHeuristic
2019-02-15 11:50:21 +00:00
CallGraph.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
CallGraphSCCPass.cpp
Fix IR/Analysis layering issue with OptBisect
2019-02-28 04:00:55 +00:00
CallPrinter.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
CaptureTracking.cpp
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2019-01-19 08:50:56 +00:00
CFG.cpp
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2019-01-19 08:50:56 +00:00
CFGPrinter.cpp
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2019-01-19 08:50:56 +00:00
CFLAndersAliasAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
CFLGraph.h
Move CFLGraph and the AA summary code over to the new CallBase
2019-02-11 09:25:41 +00:00
CFLSteensAliasAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
CGSCCPassManager.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
CMakeLists.txt
Move DomTreeUpdater from IR to Analysis
2019-02-06 02:52:52 +00:00
CmpInstAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
CodeMetrics.cpp
Remove CallSite from the CodeMetrics analysis, moving it to the new
2019-02-11 09:03:32 +00:00
ConstantFolding.cpp
[CallSite removal] Migrate ConstantFolding APIs and implementation to
2019-02-11 07:51:44 +00:00
CostModel.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
Delinearization.cpp
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2019-01-19 08:50:56 +00:00
DemandedBits.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
DependenceAnalysis.cpp
[DA][NewPM] Handle transitive dependencies in the new-pm version of DA
2019-02-03 12:25:41 +00:00
DivergenceAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
DominanceFrontier.cpp
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2019-01-19 08:50:56 +00:00
DomPrinter.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
DomTreeUpdater.cpp
[DTU] Refine the interface and logic of applyUpdates
2019-02-22 13:48:38 +00:00
EHPersonalities.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
GlobalsModRef.cpp
[NFC] fix trivial typos in comments
2019-02-05 08:30:48 +00:00
GuardUtils.cpp
[NFC] Add function to parse widenable conditional branches
2019-01-22 11:21:32 +00:00
IndirectCallPromotionAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
InlineCost.cpp
Revert "[INLINER] allow inlining of address taken blocks"
2019-02-14 23:42:21 +00:00
InstCount.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
InstructionPrecedenceTracking.cpp
Make widenable condition transparent for MemoryWriteTracking
2019-02-14 11:10:29 +00:00
InstructionSimplify.cpp
[InstSimplify] remove zero-shift-guard fold for general funnel shift
2019-02-26 18:26:56 +00:00
Interval.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
IntervalPartition.cpp
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2019-01-19 08:50:56 +00:00
IteratedDominanceFrontier.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
IVDescriptors.cpp
Move DomTreeUpdater from IR to Analysis
2019-02-06 02:52:52 +00:00
IVUsers.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
LazyBlockFrequencyInfo.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
LazyBranchProbabilityInfo.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
LazyCallGraph.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
LazyValueInfo.cpp
[NFC] fix trivial typos in comments
2019-02-05 08:30:48 +00:00
LegacyDivergenceAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
Lint.cpp
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2019-01-19 08:50:56 +00:00
LLVMBuild.txt
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
Loads.cpp
[Analysis] Fix isSafeToLoadUnconditionally handling of volatile.
2019-01-24 21:31:13 +00:00
LoopAccessAnalysis.cpp
[NFC] fix trivial typos in comments
2019-02-05 08:30:48 +00:00
LoopAnalysisManager.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
LoopInfo.cpp
Refactor setAlreadyUnrolled() and setAlreadyVectorized().
2019-02-11 19:45:44 +00:00
LoopPass.cpp
Fix IR/Analysis layering issue with OptBisect
2019-02-28 04:00:55 +00:00
LoopUnrollAnalyzer.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
MemDepPrinter.cpp
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2019-01-19 08:50:56 +00:00
MemDerefPrinter.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
MemoryBuiltins.cpp
Add a 'dynamic' parameter to the objectsize intrinsic
2019-01-30 20:34:35 +00:00
MemoryDependenceAnalysis.cpp
[NFC] Fix typos: preceeding -> preceding
2019-02-23 01:28:32 +00:00
MemoryLocation.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
MemorySSA.cpp
[MemorySSA] Remove verifyClobberSanity.
2019-02-11 19:51:21 +00:00
MemorySSAUpdater.cpp
[MemorySSA] Make insertDef insert corresponding phi nodes.
2019-02-27 22:20:22 +00:00
ModuleDebugInfoPrinter.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ModuleSummaryAnalysis.cpp
[ThinLTO] Add option to dump per-module summary dot graph
2019-01-28 23:43:26 +00:00
MustExecute.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ObjCARCAliasAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ObjCARCAnalysisUtils.cpp
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2019-01-19 08:50:56 +00:00
ObjCARCInstKind.cpp
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2019-01-19 08:50:56 +00:00
OptimizationRemarkEmitter.cpp
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2019-01-19 08:50:56 +00:00
OrderedBasicBlock.cpp
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2019-01-19 08:50:56 +00:00
OrderedInstructions.cpp
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2019-01-19 08:50:56 +00:00
PHITransAddr.cpp
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2019-01-19 08:50:56 +00:00
PhiValues.cpp
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2019-01-19 08:50:56 +00:00
PostDominators.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ProfileSummaryInfo.cpp
[PGO] Context sensitive PGO (part 2)
2019-02-28 19:55:07 +00:00
PtrUseVisitor.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
README.txt
…
RegionInfo.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
RegionPass.cpp
Fix IR/Analysis layering issue with OptBisect
2019-02-28 04:00:55 +00:00
RegionPrinter.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ScalarEvolution.cpp
[NFC] Simplify code & reduce nest slightly
2019-02-12 11:31:46 +00:00
ScalarEvolutionAliasAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ScalarEvolutionExpander.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ScalarEvolutionNormalization.cpp
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2019-01-19 08:50:56 +00:00
ScopedNoAliasAA.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
StackSafetyAnalysis.cpp
Hide two unused debugging methods, NFCI.
2019-03-01 17:15:21 +00:00
StratifiedSets.h
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
SyncDependenceAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
SyntheticCountsUtils.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
TargetLibraryInfo.cpp
[TargetLibraryInfo] Update run time support for Windows
2019-02-11 22:12:01 +00:00
TargetTransformInfo.cpp
[LSR] Generate cross iteration indexes
2019-02-07 13:32:54 +00:00
Trace.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
TypeBasedAliasAnalysis.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
TypeMetadataUtils.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ValueLattice.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ValueLatticeUtils.cpp
Update the file headers across all of the LLVM projects in the monorepo
2019-01-19 08:50:56 +00:00
ValueTracking.cpp
[ValueTracking] Known bits support for unsigned saturating add/sub
2019-03-01 20:07:04 +00:00
VectorUtils.cpp
[Vectorizer] Add vectorization support for fixed smul/umul intrinsics
2019-02-25 15:42:02 +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))

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