llvm-6502/lib/Analysis
Eli Friedman 9055ccdb6b PR9604; try to deal with RAUW updates correctly in the AST. I'm not convinced
it's completely safe to cache the AST across LICM runs even with this fix,
but this fix can't hurt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129198 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-09 06:55:46 +00:00
..
IPA
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp PR9604; try to deal with RAUW updates correctly in the AST. I'm not convinced 2011-04-09 06:55:46 +00:00
Analysis.cpp remove postdom frontiers, because it is dead. Forward dom frontiers are 2011-04-05 21:57:17 +00:00
BasicAliasAnalysis.cpp Revert r128140 for now. 2011-03-23 15:51:12 +00:00
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp Constant folding support for calls to umul.with.overflow(), basically identical to the smul.with.overflow() code. 2011-03-27 14:26:13 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp
DIBuilder.cpp Add support to encode function's template parameters. 2011-04-05 22:52:06 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InlineCost.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Avoid creating canonical induction variables for non-native types. 2011-03-18 16:50:32 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
Loads.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp Add comments for the demanglings. Correct mangled form of operator delete! 2011-03-17 05:20:12 +00:00
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp
PathProfileInfo.cpp
PathProfileVerifier.cpp
PHITransAddr.cpp
PostDominators.cpp remove postdom frontiers, because it is dead. Forward dom frontiers are 2011-04-05 21:57:17 +00:00
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp Region: Allow user control the printing style of the print function. 2011-04-04 07:19:18 +00:00
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp Added isValidRewrite() to check the result of ScalarEvolutionExpander. 2011-03-17 23:51:11 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp Remove PHINode::reserveOperandSpace(). Instead, add a parameter to 2011-03-30 11:28:46 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp Don't assume something which might be a constant expression is an instruction. 2011-04-02 22:11:56 +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.

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

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))

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