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that can have a big effect :). The first is to enable the iterative SCC passmanager juice that kicks in when the scc passmgr detects that a function pass has devirtualized a call. In this case, it will rerun all the passes it manages on the SCC, up to the iteration count limit (4). This is useful because a function pass may devirualize a call, and we want the inliner to inline it, or pruneeh to infer stuff about it, etc. The second patch is to add *all* call sites to the DevirtualizedCalls list the inliner uses. This list is about to get renamed, but the jist of this is that the inliner now reconsiders *all* inlined call sites as candidates for further inlining. The intuition is this that in cases like this: f() { g(1); } g(int x) { h(x); } We analyze this bottom up, and may decide that it isn't profitable to inline H into G. Next step, we decide that it is profitable to inline G into F, and do so, which means that F now calls H. Even though the call from G -> H may not have been profitable to inline, the call from F -> H may be (in this case because a constant allows folding etc). In my spot checks, this doesn't have a big impact on code. For example, the LLC output for 252.eon grew from 0.02% (from 317252 to 317308) and 176.gcc actually shrunk by .3% (from 1525612 to 1520964 bytes). 252.eon never iterated in the SCC Passmgr, 176.gcc iterated at most 1 time. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@102823 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. //===---------------------------------------------------------------------===// 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)) //===---------------------------------------------------------------------===//