llvm-6502/lib/Analysis
Cong Hou 1dd3d83c5e Add new constructors for LoopInfo/DominatorTree/BFI/BPI
Those new constructors make it more natural to construct an object for a function. For example, previously to build a LoopInfo for a function, we need four statements:

DominatorTree DT;
LoopInfo LI;
DT.recalculate(F);
LI.analyze(DT);

Now we only need one statement:

LoopInfo LI(DominatorTree(F));

http://reviews.llvm.org/D11274



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242486 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 23:23:35 +00:00
..
IPA [PM/AA] Fix *numerous* serious bugs in GlobalsModRef found by 2015-07-15 08:53:29 +00:00
AliasAnalysis.cpp [PM/AA] Completely remove the AliasAnalysis::copyValue interface. 2015-07-11 04:39:00 +00:00
AliasAnalysisCounter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
AliasAnalysisEvaluator.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
AliasDebugger.cpp [PM/AA] Completely remove the AliasAnalysis::copyValue interface. 2015-07-11 04:39:00 +00:00
AliasSetTracker.cpp [PM/AA] Completely remove the AliasAnalysis::copyValue interface. 2015-07-11 04:39:00 +00:00
Analysis.cpp Create a wrapper pass for BranchProbabilityInfo. 2015-07-15 22:48:29 +00:00
AssumptionCache.cpp
BasicAliasAnalysis.cpp Analyze recursive PHI nodes in BasicAA 2015-07-15 19:32:22 +00:00
BlockFrequencyInfo.cpp Add new constructors for LoopInfo/DominatorTree/BFI/BPI 2015-07-16 23:23:35 +00:00
BlockFrequencyInfoImpl.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
BranchProbabilityInfo.cpp Create a wrapper pass for BranchProbabilityInfo. 2015-07-15 22:48:29 +00:00
CaptureTracking.cpp [CaptureTracking] Avoid long compilation time on large basic blocks 2015-06-24 17:53:17 +00:00
CFG.cpp [CaptureTracking] Avoid long compilation time on large basic blocks 2015-06-24 17:53:17 +00:00
CFGPrinter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
CFLAliasAnalysis.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
CGSCCPassManager.cpp
CMakeLists.txt Move VectorUtils from Transforms to Analysis to correct layering violation 2015-06-26 18:02:52 +00:00
CodeMetrics.cpp
ConstantFolding.cpp Allow constfolding of llvm.sin.* and llvm.cos.* intrinsics 2015-07-08 03:55:47 +00:00
CostModel.cpp
Delinearization.cpp Move delinearization from SCEVAddRecExpr to ScalarEvolution 2015-06-29 14:42:48 +00:00
DependenceAnalysis.cpp Move delinearization from SCEVAddRecExpr to ScalarEvolution 2015-06-29 14:42:48 +00:00
DivergenceAnalysis.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
DominanceFrontier.cpp
DomPrinter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +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 [InstSimplify] Teach InstSimplify how to simplify extractelement 2015-07-13 01:15:53 +00:00
Interval.cpp
IntervalPartition.cpp
IteratedDominanceFrontier.cpp
IVUsers.cpp [LSR] don't attempt to promote ephemeral values to indvars 2015-07-13 03:28:53 +00:00
LazyCallGraph.cpp
LazyValueInfo.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
LLVMBuild.txt
Loads.cpp Take alignment into account in isSafeToLoadUnconditionally 2015-06-25 12:18:43 +00:00
LoopAccessAnalysis.cpp Fix memcheck interval ends for pointers with negative strides 2015-07-16 14:02:58 +00:00
LoopInfo.cpp Add new constructors for LoopInfo/DominatorTree/BFI/BPI 2015-07-16 23:23:35 +00:00
LoopPass.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
Makefile
MemDepPrinter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
MemDerefPrinter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
MemoryLocation.cpp
ModuleDebugInfoPrinter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
NoAliasAnalysis.cpp [PM/AA] Completely remove the AliasAnalysis::copyValue interface. 2015-07-11 04:39:00 +00:00
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
ScalarEvolution.cpp Move delinearization from SCEVAddRecExpr to ScalarEvolution 2015-06-29 14:42:48 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp [LSR] canonicalize Prod*(1<<C) to Prod<<C 2015-06-24 19:28:40 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
TargetLibraryInfo.cpp
TargetTransformInfo.cpp Make TargetTransformInfo keeping a reference to the Module DataLayout 2015-07-09 02:08:42 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC) 2015-06-23 09:49:53 +00:00
ValueTracking.cpp IR: Do not consider available_externally linkage to be linker-weak. 2015-07-05 20:52:35 +00:00
VectorUtils.cpp [InstSimplify] Teach InstSimplify how to simplify extractelement 2015-07-13 01:15:53 +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))

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