llvm-6502/lib/Analysis
Chandler Carruth 17395fa733 [PM] Add a utility pass template that synthesizes the invalidation of
a specific analysis result.

This is quite handy to test things, and will also likely be very useful
for debugging issues. You could narrow down pass validation failures by
walking these invalidate pass runs up and down the pass pipeline, etc.
I've added support to the pass pipeline parsing to be able to create one
of these for any analysis pass desired.

Just adding this class uncovered one latent bug where the
AnalysisManager CRTP base class had a hard-coded Module type rather than
using IRUnitT.

I've also added tests for invalidation and caching of analyses in
a basic way across all the pass managers. These in turn uncovered two
more bugs where we failed to correctly invalidate an analysis -- its
results were invalidated but the key for re-running the pass was never
cleared and so it was never re-run. Quite nasty. I'm very glad to debug
this here rather than with a full system.

Also, yes, the naming here is horrid. I'm going to update some of the
names to be slightly less awful shortly. But really, I've no "good"
ideas for naming. I'll be satisfied if I can get it to "not bad".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225246 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-06 04:49:44 +00:00
..
IPA [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
AliasAnalysis.cpp Sink store based on alias analysis 2014-12-15 14:09:53 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
AssumptionCache.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
BasicAliasAnalysis.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CFLAliasAnalysis.cpp
CGSCCPassManager.cpp [PM] Add a utility pass template that synthesizes the invalidation of 2015-01-06 04:49:44 +00:00
CMakeLists.txt [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
CodeMetrics.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ConstantFolding.cpp
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
FunctionTargetTransformInfo.cpp
InstCount.cpp
InstructionSimplify.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
JumpInstrTableInfo.cpp
LazyCallGraph.cpp [PM] Switch the new pass manager to use a reference-based API for IR 2015-01-05 02:47:05 +00:00
LazyValueInfo.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp [PM] Split the AssumptionTracker immutable pass into two separate APIs: 2015-01-04 12:03:27 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h
TargetTransformInfo.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp [PM] Cleanup a const_cast and other machinery left over in this code 2015-01-04 23:13:57 +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))

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