llvm-6502/lib/Analysis
Sanjoy Das da5f3a3ca5 [ConstantRange] Split makeICmpRegion in two.
Summary:
This change splits `makeICmpRegion` into `makeAllowedICmpRegion` and
`makeSatisfyingICmpRegion` with slightly different contracts.  The first
one is useful for determining what values some expression //may// take,
given that a certain `icmp` evaluates to true.  The second one is useful
for determining what values are guaranteed to //satisfy// a given
`icmp`.

Reviewers: nlewycky

Reviewed By: nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8345

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232575 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-18 00:41:24 +00:00
..
IPA removed function names from comments; NFC 2015-03-10 03:48:14 +00:00
AliasAnalysis.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
AliasAnalysisCounter.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasSetTracker.cpp AliasSet: Simplify mergeSetIn 2014-11-19 19:36:18 +00:00
Analysis.cpp Remove the Forward Control Flow Integrity pass and its dependencies. 2015-02-27 19:03:38 +00:00
AssumptionCache.cpp [PM] Actually add the new pass manager support for the assumption cache. 2015-01-22 21:53:09 +00:00
BasicAliasAnalysis.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
BlockFrequencyInfo.cpp [PM] Split the LoopInfo object apart from the legacy pass, creating 2015-01-17 14:16:18 +00:00
BlockFrequencyInfoImpl.cpp BFI: Saturate when combining edges to a successor 2014-12-05 19:13:42 +00:00
BranchProbabilityInfo.cpp [PM] Split the LoopInfo object apart from the legacy pass, creating 2015-01-17 14:16:18 +00:00
CaptureTracking.cpp [cleanup] Re-sort all the #include lines in LLVM using 2015-01-14 11:23:27 +00:00
CFG.cpp Standardize {pred,succ,use,user}_empty() 2015-01-13 03:46:47 +00:00
CFGPrinter.cpp
CFLAliasAnalysis.cpp Made CFLAA agree with clang-format. NFC. 2015-03-15 00:52:21 +00:00
CGSCCPassManager.cpp [PM] Remove the defunt CGSCC-specific debug flag. 2015-01-13 22:45:13 +00:00
CMakeLists.txt Remove the Forward Control Flow Integrity pass and its dependencies. 2015-02-27 19:03:38 +00:00
CodeMetrics.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ConstantFolding.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
CostModel.cpp [multiversion] Thread a function argument through all the callers of the 2015-02-01 12:01:35 +00:00
Delinearization.cpp [PM] Split the LoopInfo object apart from the legacy pass, creating 2015-01-17 14:16:18 +00:00
DependenceAnalysis.cpp Fix a memory corruption in Dependency Analysis. 2015-03-10 14:32:02 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
LazyCallGraph.cpp Revert r225854: [PM] Move the LazyCallGraph printing functionality to 2015-01-14 00:27:45 +00:00
LazyValueInfo.cpp [ConstantRange] Split makeICmpRegion in two. 2015-03-18 00:41:24 +00:00
LibCallAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LibCallSemantics.cpp Stop calling DwarfEHPrepare from WinEHPrepare 2015-03-12 00:36:20 +00:00
Lint.cpp Fix doxygen comments from r232268 2015-03-16 17:49:03 +00:00
LLVMBuild.txt Update libdeps since TLI was moved from Target to Analysis in r226078. 2015-01-15 05:21:00 +00:00
Loads.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
LoopAccessAnalysis.cpp LoopVectorize: teach loop vectorizer to vectorize calls. 2015-03-17 19:46:50 +00:00
LoopInfo.cpp [PM] Port LoopInfo to the new pass manager, adding both a LoopAnalysis 2015-01-20 10:58:50 +00:00
LoopPass.cpp [PM] Split the LoopInfo object apart from the legacy pass, creating 2015-01-17 14:16:18 +00:00
Makefile
MemDepPrinter.cpp MemDepPrinter: Fix some nits introduced in r228596 2015-02-25 23:55:00 +00:00
MemDerefPrinter.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
MemoryBuiltins.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
MemoryDependenceAnalysis.cpp DataLayout is mandatory, update the API to reflect it with references. 2015-03-10 02:37:25 +00:00
ModuleDebugInfoPrinter.cpp DebugInfo: Move new hierarchy into place 2015-03-03 17:24:31 +00:00
NoAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
PHITransAddr.cpp [opaque pointer type] more gep API migration 2015-03-14 19:53:33 +00:00
PostDominators.cpp
PtrUseVisitor.cpp Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
README.txt
RegionInfo.cpp [cleanup] Re-sort all the #include lines in LLVM using 2015-01-14 11:23:27 +00:00
RegionPass.cpp Avoid calls to dumpPassInfo and RegionBase<Tr>::getNameStr() in RGPassManager if 2015-03-06 16:15:04 +00:00
RegionPrinter.cpp
ScalarEvolution.cpp When forming an addrec out of a phi don't just look at the last computation and steal its flags for our own, there may be other computations in the middle. Check whether the LHS of the computation is the phi itself and then we know it's safe to steal the flags. Fixes PR22795. 2015-03-13 01:37:52 +00:00
ScalarEvolutionAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ScalarEvolutionExpander.cpp [SCEV] Fix PR22856. 2015-03-13 18:31:19 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
SparsePropagation.cpp
StratifiedSets.h Update SetVector to rely on the underlying set's insert to return a pair<iterator, bool> 2014-11-19 07:49:26 +00:00
TargetLibraryInfo.cpp TLI: Add addVectorizableFunctionsFromVecLib. 2015-03-17 19:50:55 +00:00
TargetTransformInfo.cpp TTI: Add getCallInstrCost. 2015-03-17 19:26:23 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp Teach TBAA analysis to report errors on cyclic TBAA metadata rather than hanging. 2015-03-13 07:09:33 +00:00
ValueTracking.cpp Infer known bits from dominating conditions 2015-03-10 22:43:20 +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))

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