llvm-mirror/lib/Analysis
Dan Gohman c40eb525ad Reapply the new LoopStrengthReduction code, with compile time and
bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.

llvm-svn: 95975
2010-02-12 10:34:29 +00:00
..
IPA Fix "the the" and similar typos. 2010-02-10 16:03:48 +00:00
AliasAnalysis.cpp Partially address a README by having functionattrs consider calls to 2010-01-06 08:45:52 +00:00
AliasAnalysisCounter.cpp drop the pass name from the output. 2010-01-22 05:52:51 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp adopt getAdjustedAnalysisPointer in a few more passes. 2010-01-20 20:09:02 +00:00
AliasSetTracker.cpp
Analysis.cpp "In order to ease automatic bindings generation, it would be helpful if boolean values were distinguishable from integers. The attached patch introduces "typedef int LLVMBool;", and uses LLVMBool instead of int throughout the C API, wherever a boolean value is called for." 2010-01-09 22:27:07 +00:00
BasicAliasAnalysis.cpp add some new methods to adjust this pointers. Not used yet. 2010-01-20 19:26:14 +00:00
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp Add const qualifiers. 2010-02-08 22:00:06 +00:00
DbgInfoPrinter.cpp Remove dead debug info intrinsics. 2010-01-05 01:10:40 +00:00
DebugInfo.cpp Set DW_AT_artificial only if argument is marked as artificial. 2010-02-06 01:02:37 +00:00
DomPrinter.cpp Create Generic DOTGraphTraits Printer/Viewer 2010-01-16 10:56:41 +00:00
InlineCost.cpp Update CodeMetrics to count 'big' function calls explicitly. 2010-02-05 23:21:18 +00:00
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Reapply the new LoopStrengthReduction code, with compile time and 2010-02-12 10:34:29 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
LiveValues.cpp Fix "the the" and similar typos. 2010-02-10 16:03:48 +00:00
LoopDependenceAnalysis.cpp
LoopInfo.cpp Restore dump() methods to Loop and MachineLoop. 2010-01-05 21:08:02 +00:00
LoopPass.cpp eliminate a bunch more unneeded dynamic_cast's. 2010-01-22 05:37:10 +00:00
Makefile make -fno-rtti the default unless a directory builds with REQUIRES_RTTI. 2010-01-24 20:43:08 +00:00
MemoryBuiltins.cpp Fix "the the" and similar typos. 2010-02-10 16:03:48 +00:00
MemoryDependenceAnalysis.cpp
PHITransAddr.cpp
PointerTracking.cpp
PostDominators.cpp
ProfileEstimatorPass.cpp adopt getAdjustedAnalysisPointer in a few more passes. 2010-01-20 20:09:02 +00:00
ProfileInfo.cpp adopt getAdjustedAnalysisPointer in a few more passes. 2010-01-20 20:09:02 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp adopt getAdjustedAnalysisPointer in a few more passes. 2010-01-20 20:09:02 +00:00
ProfileVerifierPass.cpp
README.txt
ScalarEvolution.cpp Fix "the the" and similar typos. 2010-02-10 16:03:48 +00:00
ScalarEvolutionAliasAnalysis.cpp adopt getAdjustedAnalysisPointer in a few more passes. 2010-01-20 20:09:02 +00:00
ScalarEvolutionExpander.cpp Reapply the new LoopStrengthReduction code, with compile time and 2010-02-12 10:34:29 +00:00
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp It looks like the changes to the SRem logic of SimplifyDemandedUseBits 2010-01-29 06:18:37 +00:00

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.

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