llvm-project

History

Dehao Chen 22ce5eb051 Do not widen load for different variable in GVN.

Summary:
Widening load in GVN is too early because it will block other optimizations like PRE, LICM.

https://llvm.org/bugs/show_bug.cgi?id=29110

The SPECCPU2006 benchmark impact of this patch:

Reference: o2_nopatch
(1): o2_patched

           Benchmark             Base:Reference   (1)  
-------------------------------------------------------
spec/2006/fp/C++/444.namd                  25.2  -0.08%
spec/2006/fp/C++/447.dealII               45.92  +1.05%
spec/2006/fp/C++/450.soplex                41.7  -0.26%
spec/2006/fp/C++/453.povray               35.65  +1.68%
spec/2006/fp/C/433.milc                   23.79  +0.42%
spec/2006/fp/C/470.lbm                    41.88  -1.12%
spec/2006/fp/C/482.sphinx3                47.94  +1.67%
spec/2006/int/C++/471.omnetpp             22.46  -0.36%
spec/2006/int/C++/473.astar               21.19  +0.24%
spec/2006/int/C++/483.xalancbmk           36.09  -0.11%
spec/2006/int/C/400.perlbench             33.28  +1.35%
spec/2006/int/C/401.bzip2                 22.76  -0.04%
spec/2006/int/C/403.gcc                   32.36  +0.12%
spec/2006/int/C/429.mcf                   41.04  -0.41%
spec/2006/int/C/445.gobmk                 26.94  +0.04%
spec/2006/int/C/456.hmmer                  24.5  -0.20%
spec/2006/int/C/458.sjeng                    28  -0.46%
spec/2006/int/C/462.libquantum            55.25  +0.27%
spec/2006/int/C/464.h264ref               45.87  +0.72%

geometric mean                                   +0.23%

For most benchmarks, it's a wash, but we do see stable improvements on some benchmarks, e.g. 447,453,482,400.

Reviewers: davidxl, hfinkel, dberlin, sanjoy, reames

Subscribers: gberry, junbuml

Differential Revision: https://reviews.llvm.org/D24096

llvm-svn: 281074

2016-09-09 18:42:35 +00:00

AliasAnalysis.cpp

[AliasAnalysis] Give back AA results for fence instructions

2016-07-15 17:19:24 +00:00

AliasAnalysisEvaluator.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

AliasAnalysisSummary.cpp

Update a comment.

2016-08-25 01:29:55 +00:00

AliasAnalysisSummary.h

Make some LLVM_CONSTEXPR variables const. NFC.

2016-08-25 01:05:08 +00:00

AliasSetTracker.cpp

[AliasSetTracker] Degrade AliasSetTracker when may-alias sets get too large.

2016-08-19 17:05:22 +00:00

Analysis.cpp

[BPI] Add new LazyBPI analysis

2016-07-28 23:31:12 +00:00

AssumptionCache.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

BasicAliasAnalysis.cpp

Replace a few more "fall through" comments with LLVM_FALLTHROUGH

2016-08-17 20:30:52 +00:00

BlockFrequencyInfo.cpp

s/static inline/static/ for headers I have changed in r279475. NFC.

2016-08-31 16:48:13 +00:00

BlockFrequencyInfoImpl.cpp

[GraphTraits] Replace all NodeType usage with NodeRef

2016-08-22 21:09:30 +00:00

BranchProbabilityInfo.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

CallGraph.cpp

Consistently use ModuleAnalysisManager

2016-08-09 00:28:38 +00:00

CallGraphSCCPass.cpp

RefreshCallGraph does not modify the SCC, adding "const" to make it clear (NFC)

2016-08-08 18:51:05 +00:00

CallPrinter.cpp

[CG] Rename the DOT printing pass to actually reference "DOT".

2016-03-10 11:04:40 +00:00

CaptureTracking.cpp

[CaptureTracking] Volatile operations capture their memory location

2016-05-26 17:36:22 +00:00

CFG.cpp

Avoid overly large SmallPtrSet/SmallSet

2016-01-30 01:24:31 +00:00

CFGPrinter.cpp

Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)

2015-06-23 09:49:53 +00:00

CFLAndersAliasAnalysis.cpp

Make some LLVM_CONSTEXPR variables const. NFC.

2016-08-25 01:05:08 +00:00

CFLGraph.h

[CFLAA] Check for pointer types in more places.

2016-07-29 01:23:45 +00:00

CFLSteensAliasAnalysis.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

CGSCCPassManager.cpp

Fixup r279618, instantiate *AnalysisManagerProxy<*AnalysisManager,LazyCallGraph::SCC>, instead of *AnalysisManagerProxy<*AnalysisManager,LazyCallGraph::SCC,LazyCallGraph&>, for PassID.

2016-08-30 15:47:13 +00:00

CMakeLists.txt

[BPI] Add new LazyBPI analysis

2016-07-28 23:31:12 +00:00

CodeMetrics.cpp

[Assumptions] Make collecting ephemeral values not quadratic in the

2016-08-18 17:51:24 +00:00

ConstantFolding.cpp

Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes.

2016-08-25 00:45:04 +00:00

CostModel.cpp

[LV, X86] Be more optimistic about vectorizing shifts.

2016-08-04 22:48:03 +00:00

Delinearization.cpp

[NFC] Header cleanup

2016-04-18 09:17:29 +00:00

DemandedBits.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

DependenceAnalysis.cpp

Apply clang-tidy's modernize-loop-convert to lib/Analysis.

2016-06-26 17:27:42 +00:00

DivergenceAnalysis.cpp

DivergenceAnalysis: Fix crash with no return blocks

2016-05-09 16:57:08 +00:00

DominanceFrontier.cpp

[PM] Make the AnalysisManager parameter to run methods a reference.

2016-03-11 11:05:24 +00:00

DomPrinter.cpp

Introduce analysis pass to compute PostDominators in the new pass manager. NFC

2016-02-25 17:54:07 +00:00

EHPersonalities.cpp

Use the range variant of find instead of unpacking begin/end

2016-08-11 22:21:41 +00:00

GlobalsModRef.cpp

Use the range variant of find instead of unpacking begin/end

2016-08-11 22:21:41 +00:00

IndirectCallPromotionAnalysis.cpp

Remove another unused variable from r275216

2016-07-12 23:49:17 +00:00

InlineCost.cpp

Fix a thinko in r278189.

2016-08-29 20:45:51 +00:00

InstCount.cpp

Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)

2015-06-23 09:49:53 +00:00

InstructionSimplify.cpp

Simplify code a bit. No functional change intended.

2016-09-02 15:55:25 +00:00

Interval.cpp

Apply clang-tidy's modernize-loop-convert to lib/Analysis.

2016-06-26 17:27:42 +00:00

IntervalPartition.cpp

Apply clang-tidy's modernize-loop-convert to lib/Analysis.

2016-06-26 17:27:42 +00:00

IteratedDominanceFrontier.cpp

Normalize file docs. NFC.

2016-07-21 20:52:35 +00:00

IVUsers.cpp

Consistently use LoopAnalysisManager

2016-08-09 00:28:52 +00:00

LazyBlockFrequencyInfo.cpp

[BPI] Add new LazyBPI analysis

2016-07-28 23:31:12 +00:00

LazyBranchProbabilityInfo.cpp

[BPI] Add new LazyBPI analysis

2016-07-28 23:31:12 +00:00

LazyCallGraph.cpp

[LCG] Clean up and make NDEBUG verify calls more rigorous with

2016-09-04 08:34:31 +00:00

LazyValueInfo.cpp

[LVI] Take guards into account

2016-08-12 15:52:23 +00:00

Lint.cpp

Fix some Clang-tidy modernize-use-using and Include What You Use warnings.

2016-08-13 00:50:41 +00:00

LLVMBuild.txt

Refactor indirect call promotion profitability analysis (NFC)

2016-07-12 21:13:44 +00:00

Loads.cpp

[Loads] Properly populate the visited set in isDereferenceableAndAlignedPointer

2016-08-31 03:22:32 +00:00

LoopAccessAnalysis.cpp

Fix indent. NFC.

2016-08-31 18:37:52 +00:00

LoopInfo.cpp

[LoopInfo] Add verification by recomputation.

2016-08-31 19:26:19 +00:00

LoopPass.cpp

Consistently use LoopAnalysisManager

2016-08-09 00:28:52 +00:00

LoopPassManager.cpp

PM: Check that loop passes preserve a basic set of analyses

2016-05-03 21:35:08 +00:00

LoopUnrollAnalyzer.cpp

[LoopUnrollAnalyzer] Handle out of bounds accesses in visitLoad

2016-07-23 02:56:49 +00:00

MemDepPrinter.cpp

Apply clang-tidy's modernize-loop-convert to lib/Analysis.

2016-06-26 17:27:42 +00:00

MemDerefPrinter.cpp

NFC. Move isDereferenceable to Loads.h/cpp

2016-02-24 12:49:04 +00:00

MemoryBuiltins.cpp

Make some LLVM_CONSTEXPR variables const. NFC.

2016-08-25 01:05:08 +00:00

MemoryDependenceAnalysis.cpp

Do not widen load for different variable in GVN.

2016-09-09 18:42:35 +00:00

MemoryLocation.cpp

[TLI] Unify LibFunc signature checking. NFCI.

2016-04-27 19:04:35 +00:00

ModuleDebugInfoPrinter.cpp

Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)

2015-06-23 09:49:53 +00:00

ModuleSummaryAnalysis.cpp

NFC: add early exit in ModuleSummaryAnalysis

2016-08-30 00:46:26 +00:00

ObjCARCAliasAnalysis.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

ObjCARCAnalysisUtils.cpp

[ARC] Pull the ObjC ARC components that really serve the role of

2015-08-20 08:06:03 +00:00

ObjCARCInstKind.cpp

ObjCARC: Don't increment or dereference end() when scanning args

2016-08-17 01:02:18 +00:00

OptimizationDiagnosticInfo.cpp

[Inliner] Report when inlining fails because callee's def is unavailable

2016-08-26 20:21:05 +00:00

OrderedBasicBlock.cpp

[CaptureTracker] Provide an ordered basic block to PointerMayBeCapturedBefore

2015-07-31 14:31:35 +00:00

PHITransAddr.cpp

Use the range variant of find instead of unpacking begin/end

2016-08-11 22:21:41 +00:00

PostDominators.cpp

[PM] Remove support for omitting the AnalysisManager argument to new

2016-06-17 00:11:01 +00:00

ProfileSummaryInfo.cpp

Consistently use ModuleAnalysisManager

2016-08-09 00:28:38 +00:00

PtrUseVisitor.cpp

…

README.txt

…

RegionInfo.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

RegionPass.cpp

[RegionPass] Some minor cleanups

2016-07-19 17:50:27 +00:00

RegionPrinter.cpp

Apply clang-tidy's modernize-loop-convert to lib/Analysis.

2016-06-26 17:27:42 +00:00

ScalarEvolution.cpp

SCEV: Don't assert about non-SCEV-able value in isSCEVExprNeverPoison() (PR28932)

2016-08-17 22:50:18 +00:00

ScalarEvolutionAliasAnalysis.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

ScalarEvolutionExpander.cpp

Use range algorithms instead of unpacking begin/end

2016-08-11 21:15:00 +00:00

ScalarEvolutionNormalization.cpp

Remove emacs mode markers from .cpp files. NFC

2016-04-24 17:55:41 +00:00

ScopedNoAliasAA.cpp

[ScopedNoAliasAA] collectMDInDomain should be a free function

2016-08-15 03:56:06 +00:00

SparsePropagation.cpp

Apply clang-tidy's modernize-loop-convert to lib/Analysis.

2016-06-26 17:27:42 +00:00

StratifiedSets.h

[CFLAA] Simplify CFLGraphBuilder. NFC.

2016-07-11 22:59:09 +00:00

TargetLibraryInfo.cpp

Replace a few more "fall through" comments with LLVM_FALLTHROUGH

2016-08-17 20:30:52 +00:00

TargetTransformInfo.cpp

[LoopStrenghtReduce] Refactoring and addition of a new target cost function.

2016-08-17 13:24:19 +00:00

Trace.cpp

Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment.

2016-01-29 20:50:44 +00:00

TypeBasedAliasAnalysis.cpp

Consistently use FunctionAnalysisManager

2016-08-09 00:28:15 +00:00

TypeMetadataUtils.cpp

[IR] Make getIndexedOffsetInType return a signed result

2016-07-13 03:42:38 +00:00

ValueTracking.cpp

The patch improves ValueTracking on left shift with nsw flag.

2016-08-24 23:01:33 +00:00

VectorUtils.cpp

SLPVectorizer: Move propagateMetadata to VectorUtils

2016-06-30 21:17:59 +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))

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