Andrew Trick 10bb82e54f Rewrite SCEV's backedge taken count computation. ... Patch by Michele Scandale! Rewrite of the functions used to compute the backedge taken count of a loop on LT and GT comparisons. I decided to split the handling of LT and GT cases becasue the trick "a > b == -a < -b" in some cases prevents the trip count computation due to the multiplication by -1 on the two operands of the comparison. This issue comes from the conservative computation of value range of SCEVs: taking the negative SCEV of an expression that have a small positive range (e.g. [0,31]), we would have a SCEV with a fullset as value range. Indeed, in the new rewritten function I tried to better handle the maximum backedge taken count computation when MAX/MIN expression are used to handle the cases where no entry guard is found. Some test have been modified in order to check the new value correctly (I manually check them and reasoning on possible overflow the new values seem correct). I finally added a new test case related to the multiplication by -1 issue on GT comparisons. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194116 91177308-0d34-0410-b5e6-96231b3b80d8		2013-11-06 02:08:26 +00:00
..
AliasAnalysis.h	Make BasicAliasAnalysis recognize the fact a noalias argument cannot alias another argument, even if the other argument is not itself marked noalias.	2013-05-28 08:17:48 +00:00
AliasSetTracker.h	Remove unneeded #includes.	2013-03-18 23:33:44 +00:00
BlockFrequencyImpl.h	Add some constantness.	2013-08-20 23:04:15 +00:00
BlockFrequencyInfo.h	Fixed 80+ violation and added C++ to header.	2013-07-12 23:09:43 +00:00
BranchProbabilityInfo.h	Add a new function attribute 'cold' to functions.	2013-05-24 12:26:52 +00:00
CallGraph.h	Merge CallGraph and BasicCallGraph.	2013-10-31 03:03:55 +00:00
CallGraphSCCPass.h
CallPrinter.h
CaptureTracking.h	Remove unneeded #includes. Use forward declarations instead.	2013-03-10 00:34:01 +00:00
CFG.h	Add some constantness.	2013-08-20 23:04:15 +00:00
CFGPrinter.h
CodeMetrics.h
ConstantFolding.h	Add missing -*- C++ -*- to headers	2013-05-17 21:43:39 +00:00
ConstantsScanner.h
DependenceAnalysis.h	Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.	2013-07-14 04:42:23 +00:00
DominanceFrontier.h
DominatorInternals.h
Dominators.h	Add function DominatorTree::getDescendants().	2013-09-19 17:18:35 +00:00
DomPrinter.h
DOTGraphTraitsPass.h
FindUsedTypes.h
InlineCost.h	Remove unneeded #include.	2013-06-06 23:34:11 +00:00
InstructionSimplify.h	Fix missing -*- C++ -*-s	2013-08-06 00:16:21 +00:00
Interval.h
IntervalIterator.h
IntervalPartition.h
IVUsers.h
LazyValueInfo.h
LibCallAliasAnalysis.h
LibCallSemantics.h
Lint.h
Loads.h
LoopInfo.h	Quick look-up for block in loop.	2013-10-26 03:08:02 +00:00
LoopInfoImpl.h	Quick look-up for block in loop.	2013-10-26 03:08:02 +00:00
LoopIterator.h
LoopPass.h
MemoryBuiltins.h	fix PR17635: false positive with packed structures	2013-10-24 09:17:24 +00:00
MemoryDependenceAnalysis.h	Memory Dependence Analysis (not mem-dep test) take advantage of "invariant.load" metadata.	2013-03-06 17:48:48 +00:00
Passes.h	Remove the very substantial, largely unmaintained legacy PGO	2013-10-02 15:42:23 +00:00
PHITransAddr.h
PostDominators.h	Add a const version of findNearestCommonDominator to PostDom for convenience.	2013-06-09 15:09:30 +00:00
PtrUseVisitor.h
RegionInfo.h	RegionInfo: Add helpers to replace entry/exit recursively	2013-04-10 06:54:49 +00:00
RegionIterator.h
RegionPass.h	Fix a typo (ouput => output)	2013-05-17 12:31:43 +00:00
RegionPrinter.h
ScalarEvolution.h	Rewrite SCEV's backedge taken count computation.	2013-11-06 02:08:26 +00:00
ScalarEvolutionExpander.h	Fix SCEVExpander: don't try to expand quadratic recurrences outside a loop.	2013-10-25 21:35:56 +00:00
ScalarEvolutionExpressions.h
ScalarEvolutionNormalization.h
SparsePropagation.h
TargetTransformInfo.h	Speling fixes.	2013-10-22 15:18:03 +00:00
Trace.h
ValueTracking.h	Teach MemoryBuiltins and InstructionSimplify that operator new never returns NULL.	2013-09-24 16:37:51 +00:00
Verifier.h