llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 20:32:21 +00:00

History

Duncan Sands 163a84bbce Add an m_Div pattern for matching either a udiv or an sdiv and use it to simplify the "(X/Y)*Y->X when the division is exact" transform. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125004 91177308-0d34-0410-b5e6-96231b3b80d8		2011-02-07 09:36:32 +00:00
..
IPA	Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment,	2011-01-03 23:51:43 +00:00
AliasAnalysis.cpp	Stub out a new updating interface to AliasAnalysis, allowing stateful analyses to be informed when	2011-01-03 21:38:41 +00:00
AliasAnalysisCounter.cpp	Teach AliasAnalysisCounter about PartialAlias.	2010-12-10 19:53:05 +00:00
AliasAnalysisEvaluator.cpp	Teach AliasAnalysisEvaluator about PartialAlias.	2010-12-10 19:52:40 +00:00
AliasDebugger.cpp	Extend the AliasAnalysis::pointsToConstantMemory interface to allow it	2010-11-08 16:45:26 +00:00
AliasSetTracker.cpp	Update this code to handle PartialAlias as MayAlias.	2010-12-10 19:40:47 +00:00
Analysis.cpp	Implementation of path profiling.	2011-01-29 01:09:53 +00:00
BasicAliasAnalysis.cpp	Give GetUnderlyingObject a TargetData, to keep it in sync	2011-01-24 18:53:32 +00:00
CaptureTracking.cpp	VAArg doesn't capture its operand.	2010-11-09 20:09:35 +00:00
CFGPrinter.cpp
CMakeLists.txt	Implementation of path profiling.	2011-01-29 01:09:53 +00:00
ConstantFolding.cpp	Simplify test, as suggested by Chris.	2011-02-06 20:22:49 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Fix typo in comment.	2011-02-03 00:13:47 +00:00
DIBuilder.cpp	Add support to describe template value parameter in debug info.	2011-02-02 22:35:53 +00:00
DominanceFrontier.cpp	Move DominanceFrontier from VMCore to Analysis.	2011-01-18 06:06:27 +00:00
DomPrinter.cpp	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
InlineCost.cpp	Remove premature optimization that avoided calculating argument weights	2011-02-06 21:27:46 +00:00
InstCount.cpp
InstructionSimplify.cpp	Add an m_Div pattern for matching either a udiv or an sdiv and use it	2011-02-07 09:36:32 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
LazyValueInfo.cpp	Teach LazyValueInfo that allocas aren't NULL. Over all of llvm-test, this saves	2011-01-15 09:16:12 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Give GetUnderlyingObject a TargetData, to keep it in sync	2011-01-24 18:53:32 +00:00
LiveValues.cpp	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
Loads.cpp	Move Value::getUnderlyingObject to be a standalone	2010-12-15 20:02:24 +00:00
LoopDependenceAnalysis.cpp	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
LoopInfo.cpp	Fix typo pointed out by Trevor Harmon.	2010-11-13 12:16:27 +00:00
LoopPass.cpp
Makefile
MemDepPrinter.cpp	Add helper functions for computing the Location of load, store,	2010-11-11 21:50:19 +00:00
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	Give GetUnderlyingObject a TargetData, to keep it in sync	2011-01-24 18:53:32 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp	Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment,	2011-01-03 23:51:43 +00:00
PathNumbering.cpp	Implementation of path profiling.	2011-01-29 01:09:53 +00:00
PathProfileInfo.cpp	Implementation of path profiling.	2011-01-29 01:09:53 +00:00
PathProfileVerifier.cpp	Implementation of path profiling.	2011-01-29 01:09:53 +00:00
PHITransAddr.cpp	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
PostDominators.cpp	split dom frontier handling stuff out to its own DominanceFrontier header,	2011-01-02 22:09:33 +00:00
ProfileEstimatorPass.cpp	fix PR8928 by clearing a stale map, patch by Jakub Staszak!	2011-01-24 18:36:51 +00:00
ProfileInfo.cpp	Null initialize a few variables flagged by	2011-01-23 17:05:06 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp	Add single entry / single exit accessors.	2011-01-13 23:18:04 +00:00
RegionPass.cpp	Remove useless dynamic_cast<>().	2010-12-12 21:58:28 +00:00
RegionPrinter.cpp
ScalarEvolution.cpp	Fix memory corruption. If one of the SCEV creation functions calls another but	2011-01-26 08:40:22 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Introduce memoization for ScalarEvolution dominates and properlyDominates	2010-11-18 00:34:22 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp	Update a comment.	2010-12-16 02:55:10 +00:00
ValueTracking.cpp	Add a m_SignBit pattern for convenience.	2011-02-01 08:50:33 +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))

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