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08e322db8a
we have RefreshCallGraph detect when a function pass devirtualizes a call, and have CGSCCPassMgr iterate (up to a count) when this happens. This allows (in the example) GVN to devirtualize the call in foo, then the inliner to inline it away. This is not currently enabled because I haven't done any analysis on the (potentially substantial) code size or performance impact of doing this, and guess what, it exposes callgraph updating bugs in various passes. This is progress though, and you can play with it by passing -max-cg-scc-iterations=5 to opt. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101973 91177308-0d34-0410-b5e6-96231b3b80d8 |
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| .. | ||
| IPA | ||
| AliasAnalysis.cpp | ||
| AliasAnalysisCounter.cpp | ||
| AliasAnalysisEvaluator.cpp | ||
| AliasDebugger.cpp | ||
| AliasSetTracker.cpp | ||
| Analysis.cpp | ||
| BasicAliasAnalysis.cpp | ||
| CaptureTracking.cpp | ||
| CFGPrinter.cpp | ||
| CMakeLists.txt | ||
| ConstantFolding.cpp | ||
| DbgInfoPrinter.cpp | ||
| DebugInfo.cpp | ||
| DomPrinter.cpp | ||
| InlineCost.cpp | ||
| InstCount.cpp | ||
| InstructionSimplify.cpp | ||
| Interval.cpp | ||
| IntervalPartition.cpp | ||
| IVUsers.cpp | ||
| LazyValueInfo.cpp | ||
| LibCallAliasAnalysis.cpp | ||
| LibCallSemantics.cpp | ||
| Lint.cpp | ||
| LiveValues.cpp | ||
| LoopDependenceAnalysis.cpp | ||
| LoopInfo.cpp | ||
| LoopPass.cpp | ||
| Makefile | ||
| MemoryBuiltins.cpp | ||
| MemoryDependenceAnalysis.cpp | ||
| PHITransAddr.cpp | ||
| PointerTracking.cpp | ||
| PostDominators.cpp | ||
| ProfileEstimatorPass.cpp | ||
| ProfileInfo.cpp | ||
| ProfileInfoLoader.cpp | ||
| ProfileInfoLoaderPass.cpp | ||
| ProfileVerifierPass.cpp | ||
| README.txt | ||
| ScalarEvolution.cpp | ||
| ScalarEvolutionAliasAnalysis.cpp | ||
| ScalarEvolutionExpander.cpp | ||
| ScalarEvolutionNormalization.cpp | ||
| SparsePropagation.cpp | ||
| Trace.cpp | ||
| ValueTracking.cpp | ||
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.
//===---------------------------------------------------------------------===//