llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 04:30:23 +00:00

History

Chris Lattner 79fa3cf451 constant fold nasty constant expressions formed by llvm-gcc, wrapping up PR3351. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92410 91177308-0d34-0410-b5e6-96231b3b80d8		2010-01-02 01:22:23 +00:00
..
IPA	Change dbgs() back to errs() for assert messages as Chris requested.	2009-12-23 23:14:41 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp	Change dbgs() back to errs() as Chris requested.	2009-12-23 22:49:57 +00:00
AliasAnalysisEvaluator.cpp	Change dbgs() back to errs() as Chris requested.	2009-12-23 22:49:57 +00:00
AliasDebugger.cpp
AliasSetTracker.cpp	Change dbgs() back to errs() as Chris requested.	2009-12-23 22:49:57 +00:00
Analysis.cpp
BasicAliasAnalysis.cpp	move DecomposeGEPExpression out into ValueTracking.cpp	2009-11-26 17:12:50 +00:00
CaptureTracking.cpp	Reuse the Threshold value to size these containers because it's	2009-12-09 18:48:53 +00:00
CFGPrinter.cpp
CMakeLists.txt	add to cmake	2009-12-04 04:15:36 +00:00
ConstantFolding.cpp	constant fold nasty constant expressions formed by llvm-gcc,	2010-01-02 01:22:23 +00:00
DbgInfoPrinter.cpp	fix Analysis/DebugInfo.h to not include Metadata.h. Do this	2009-12-31 03:02:08 +00:00
DebugInfo.cpp	fix Analysis/DebugInfo.h to not include Metadata.h. Do this	2009-12-31 03:02:08 +00:00
DomPrinter.cpp	Remove ShortNames from getNodeLabel in DOTGraphTraits	2009-11-30 12:38:47 +00:00
InlineCost.cpp
InstCount.cpp	Change dbgs() back to errs() as Chris requested.	2009-12-23 23:29:28 +00:00
InstructionSimplify.cpp	factor some logic out of instcombine into a new SimplifyAddInst method.	2009-11-27 17:42:22 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 20:20:46 +00:00
LazyValueInfo.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 20:43:58 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
LiveValues.cpp
LoopDependenceAnalysis.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 20:52:41 +00:00
LoopInfo.cpp	Add Loop contains utility methods for testing whether a loop	2009-12-18 01:24:09 +00:00
LoopPass.cpp
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	The phi translated pointer can be computed when returning a partially cached result	2009-12-22 04:25:02 +00:00
PHITransAddr.cpp	Change dbgs() back to errs() as Chris requested.	2009-12-23 23:27:15 +00:00
PointerTracking.cpp
PostDominators.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 21:16:54 +00:00
ProfileEstimatorPass.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 21:27:29 +00:00
ProfileInfo.cpp	Change dbgs() back to errs() for assert messages as Chris requested.	2009-12-23 22:59:29 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp	Change dbgs() back to errs() for assert messages as Chris requested.	2009-12-23 23:00:50 +00:00
ProfileVerifierPass.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 22:10:20 +00:00
README.txt
ScalarEvolution.cpp	Remove dump routine and the associated Debug.h from a header. Patch up	2009-12-23 22:58:38 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Fix a comment typo.	2009-12-04 01:33:04 +00:00
SparsePropagation.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 22:28:01 +00:00
Trace.cpp	Convert debug messages to use dbgs(). Generally this means	2009-12-23 22:35:10 +00:00
ValueTracking.cpp	Fix GetConstantStringInfo to not look into MDString (it works on	2009-12-15 19:34:20 +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.

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