Duncan Sands 593faa53fa My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC ... benchmarks, and that it can be simplified to X/Y. (In general you can only simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the form "X/Y" then this is the case). This patch implements that transform and moves some Div logic out of instcombine and into InstructionSimplify. Unfortunately instcombine gets in the way somewhat, since it likes to change (X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too. Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y" does not overflow, because the flag says so, so I added that logic too. This eliminates a bunch of divisions and subtractions in 447.dealII, and has good effects on some other benchmarks too. It seems to have quite an effect on tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions changed, resulting in massive changes all over. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124487 91177308-0d34-0410-b5e6-96231b3b80d8		2011-01-28 16:51:11 +00:00
..
AliasAnalysis.h	fit in 80 cols	2011-01-08 20:53:41 +00:00
AliasSetTracker.h	Reapply r116831 and r116839, converting AliasAnalysis to use	2010-10-19 22:54:46 +00:00
CallGraph.h	Add spliceFunction to the CallGraph interface. This allows users to efficiently	2011-01-03 03:19:35 +00:00
CaptureTracking.h	80-columns	2010-07-13 05:50:08 +00:00
CFGPrinter.h	Remove tab characters and 80-col.	2010-07-12 05:26:37 +00:00
CodeMetrics.h	remove the partial specialization pass. It is unmaintained and has bugs.	2011-01-16 00:27:10 +00:00
ConstantFolding.h	Clarify that constant folding of instructions applies when all operands	2010-11-23 10:16:18 +00:00
ConstantsScanner.h
DebugInfo.h	Add support to create class type.	2010-12-08 20:18:20 +00:00
DIBuilder.h	Add support to create debug info for functions and methods.	2010-12-08 20:42:44 +00:00
DominanceFrontier.h	There is no point in verifying an analysis that is never updated.	2011-01-18 05:44:04 +00:00
DominatorInternals.h	Convert a std::vector to a SmallVector for another 5.4% speedup on domtree.	2011-01-23 06:54:22 +00:00
Dominators.h	In the simpler version of the link-eval data structure that we use in dominator	2011-01-23 06:16:06 +00:00
DomPrinter.h
DOTGraphTraitsPass.h	Remove WriteGraph's Name argument, which it didn't use, and	2010-09-27 15:34:19 +00:00
FindUsedTypes.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
InlineCost.h	Temporarily revert 124275 to see if it brings the dragonegg buildbot back.	2011-01-26 19:40:31 +00:00
InstructionSimplify.h	My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC	2011-01-28 16:51:11 +00:00
Interval.h
IntervalIterator.h
IntervalPartition.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
IVUsers.h	Revert 112442 and 112440 until the compile time problems introduced	2010-09-01 01:45:53 +00:00
LazyValueInfo.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LibCallAliasAnalysis.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LibCallSemantics.h	Remove the experimental AliasAnalysis::getDependency interface, which	2010-09-14 21:25:10 +00:00
Lint.h
LiveValues.h
Loads.h
LoopDependenceAnalysis.h	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LoopInfo.h	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
LoopPass.h	Make LoopPass::getContainedPass return a LoopPass* instead of a Pass*	2010-08-11 20:34:43 +00:00
MemoryBuiltins.h	clean up handling of 'free', detangling it from everything else.	2010-11-30 01:28:33 +00:00
MemoryDependenceAnalysis.h	Rewrite the main DSE loop to be written in terms of reasoning	2010-11-30 07:23:21 +00:00
Passes.h	Move NoAA out of BasicAliasAnalysis.cpp into its own file, now that	2010-10-19 23:09:08 +00:00
PHITransAddr.h
PostDominators.h	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
ProfileInfo.h
ProfileInfoLoader.h
ProfileInfoTypes.h
RegionInfo.h	Add single entry / single exit accessors.	2011-01-13 23:18:04 +00:00
RegionIterator.h	Add new RegionInfo pass.	2010-07-22 07:46:31 +00:00
RegionPass.h	Add RegionPass support.	2010-10-20 01:54:44 +00:00
RegionPrinter.h	Add new RegionInfo pass.	2010-07-22 07:46:31 +00:00
ScalarEvolution.h	some comment improvements.	2011-01-11 17:11:59 +00:00
ScalarEvolutionExpander.h	Introduce memoization for ScalarEvolution dominates and properlyDominates	2010-11-18 00:34:22 +00:00
ScalarEvolutionExpressions.h	Make SCEV::getType() and SCEV::print non-virtual. Move SCEV::hasOperand	2010-11-17 22:27:42 +00:00
ScalarEvolutionNormalization.h
SparsePropagation.h
Trace.h
ValueTracking.h	According to my auto-simplifier the most common missed simplifications in	2011-01-25 09:38:29 +00:00
Verifier.h