llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-16 12:24:44 +00:00

History

Chris Lattner c8e14b3d37 fix incorrect folding of icmp with undef, PR6481. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97659 91177308-0d34-0410-b5e6-96231b3b80d8		2010-03-03 19:46:03 +00:00
..
IPA	Update CMake build.	2010-03-01 19:42:47 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp	Fix a missing newline in debug output.	2010-03-01 17:42:55 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp	Remove the code which constant-folded ptrtoint(inttoptr(x)+c) to	2010-02-23 16:35:41 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Use line and column number to distinguish two lexical blocks at the same level.	2010-02-16 21:39:34 +00:00
DomPrinter.cpp
InlineCost.cpp
InstCount.cpp
InstructionSimplify.cpp	fix incorrect folding of icmp with undef, PR6481.	2010-03-03 19:46:03 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	Spelling fixes.	2010-03-01 17:49:51 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
LiveValues.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	Reapply r97010, the speculative revert failed.	2010-02-24 08:48:04 +00:00
PHITransAddr.cpp	Reapply r97010, the speculative revert failed.	2010-02-24 08:48:04 +00:00
PointerTracking.cpp
PostDominators.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
ScalarEvolution.cpp	Spelling fixes.	2010-03-01 17:49:51 +00:00
ScalarEvolutionAliasAnalysis.cpp	Add a comment.	2010-03-01 17:56:04 +00:00
ScalarEvolutionExpander.cpp	Make SCEVExpander and LSR more aggressive about hoisting expressions out	2010-03-03 05:29:13 +00:00
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp

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.

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