llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-02 22:04:55 +00:00

History

Andreas Neustifter 1640f7e033 Do not create negative edge weights in ProfileEstimator. Use integer values for weights to prevent rounding errors. Make ProfileEstimator more robust in general CFGs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90449 91177308-0d34-0410-b5e6-96231b3b80d8		2009-12-03 12:41:14 +00:00
..
IPA
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp	fix PR5673 by being more careful about pointers to functions.	2009-12-03 01:05:45 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Add utility routine to create subprogram definition entry from subprogram declaration entry.	2009-12-01 23:09:02 +00:00
DomPrinter.cpp	Remove ShortNames from getNodeLabel in DOTGraphTraits	2009-11-30 12:38:47 +00:00
InlineCost.cpp
InstCount.cpp
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
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
LiveValues.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	Silence compiler warnings.	2009-12-02 15:33:44 +00:00
PointerTracking.cpp
PostDominators.cpp
ProfileEstimatorPass.cpp	Do not create negative edge weights in ProfileEstimator.	2009-12-03 12:41:14 +00:00
ProfileInfo.cpp	Converted ProfileInfo to template, added more API for ProfileInfo-preserving.	2009-12-03 09:30:12 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp	Use ProfileInfo-API in ProfileInfo Loader and do more assertions.	2009-12-03 11:00:37 +00:00
ProfileVerifierPass.cpp
README.txt
ScalarEvolution.cpp
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	improve portability to avoid conflicting with std::next in c++'0x.	2009-12-03 00:50:42 +00:00
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp	Fixed an assertion failure for tracking sext of a vector of integers	2009-12-02 04:59:58 +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.

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