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64b906419e
If we have a caller that knows a particular argument can never be null, we can exploit this fact while simplifying values in the inline cost analysis. This has the effect of reducing the cost for inlining when a null check is present in the callee, but the value is known non null in the caller. In particular, any dependent control flow can be discounted from the cost estimate. Note that we use the parameter attributes at the call site to memoize the analysis within the caller's code. The setting of this attribute is done in InstCombine, the inline cost analysis just consumes it. This is intentional and important because we want the inline cost analysis results to be easily cachable themselves. We're not currently doing so, but initial results on LTO indicate this will quickly become important. Differential Revision: http://reviews.llvm.org/D9129 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240828 91177308-0d34-0410-b5e6-96231b3b80d8 |
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| .. | ||
| IPA | ||
| AliasAnalysis.cpp | ||
| AliasAnalysisCounter.cpp | ||
| AliasAnalysisEvaluator.cpp | ||
| AliasDebugger.cpp | ||
| AliasSetTracker.cpp | ||
| Analysis.cpp | ||
| AssumptionCache.cpp | ||
| BasicAliasAnalysis.cpp | ||
| BlockFrequencyInfo.cpp | ||
| BlockFrequencyInfoImpl.cpp | ||
| BranchProbabilityInfo.cpp | ||
| CaptureTracking.cpp | ||
| CFG.cpp | ||
| CFGPrinter.cpp | ||
| CFLAliasAnalysis.cpp | ||
| CGSCCPassManager.cpp | ||
| CMakeLists.txt | ||
| CodeMetrics.cpp | ||
| ConstantFolding.cpp | ||
| CostModel.cpp | ||
| Delinearization.cpp | ||
| DependenceAnalysis.cpp | ||
| DivergenceAnalysis.cpp | ||
| DominanceFrontier.cpp | ||
| DomPrinter.cpp | ||
| InstCount.cpp | ||
| InstructionSimplify.cpp | ||
| Interval.cpp | ||
| IntervalPartition.cpp | ||
| IteratedDominanceFrontier.cpp | ||
| IVUsers.cpp | ||
| LazyCallGraph.cpp | ||
| LazyValueInfo.cpp | ||
| LibCallAliasAnalysis.cpp | ||
| LibCallSemantics.cpp | ||
| Lint.cpp | ||
| LLVMBuild.txt | ||
| Loads.cpp | ||
| LoopAccessAnalysis.cpp | ||
| LoopInfo.cpp | ||
| LoopPass.cpp | ||
| Makefile | ||
| MemDepPrinter.cpp | ||
| MemDerefPrinter.cpp | ||
| MemoryBuiltins.cpp | ||
| MemoryDependenceAnalysis.cpp | ||
| MemoryLocation.cpp | ||
| ModuleDebugInfoPrinter.cpp | ||
| NoAliasAnalysis.cpp | ||
| PHITransAddr.cpp | ||
| PostDominators.cpp | ||
| PtrUseVisitor.cpp | ||
| README.txt | ||
| RegionInfo.cpp | ||
| RegionPass.cpp | ||
| RegionPrinter.cpp | ||
| ScalarEvolution.cpp | ||
| ScalarEvolutionAliasAnalysis.cpp | ||
| ScalarEvolutionExpander.cpp | ||
| ScalarEvolutionNormalization.cpp | ||
| ScopedNoAliasAA.cpp | ||
| SparsePropagation.cpp | ||
| StratifiedSets.h | ||
| TargetLibraryInfo.cpp | ||
| TargetTransformInfo.cpp | ||
| Trace.cpp | ||
| TypeBasedAliasAnalysis.cpp | ||
| ValueTracking.cpp | ||
| VectorUtils.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.
//===---------------------------------------------------------------------===//
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))
//===---------------------------------------------------------------------===//