Reapply "[nfc][mlgo] Incrementally update DominatorTreeAnalysis in FunctionPropertiesAnalysis (#104867) #106309
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…nctionPropertiesAnalysis (llvm#104867) Reverts c992690. The problem is that if there is a sequence "{delete A->B} {delete A->B} {insert A->B}" the net result is "{delete A->B}", which is not what we want. The fix is to sanitize the list of deletes, just like we do for inserts.
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@llvm/pr-subscribers-mlgo @llvm/pr-subscribers-llvm-analysis Author: Mircea Trofin (mtrofin) ChangesReverts c992690. The problem is that if there is a sequence "{delete A->B} {delete A->B} {insert A->B}" the net result is "{delete A->B}", which is not what we want. The fix is to sanitize the list of deletes, just like we do for inserts. Full diff: https://github.com/llvm/llvm-project/pull/106309.diff 4 Files Affected:
diff --git a/llvm/include/llvm/Analysis/FunctionPropertiesAnalysis.h b/llvm/include/llvm/Analysis/FunctionPropertiesAnalysis.h
index ee447d3e4ebb6a..af72f6e0f90b11 100644
--- a/llvm/include/llvm/Analysis/FunctionPropertiesAnalysis.h
+++ b/llvm/include/llvm/Analysis/FunctionPropertiesAnalysis.h
@@ -15,6 +15,7 @@
#define LLVM_ANALYSIS_FUNCTIONPROPERTIESANALYSIS_H
#include "llvm/ADT/DenseSet.h"
+#include "llvm/IR/Dominators.h"
#include "llvm/IR/PassManager.h"
namespace llvm {
@@ -186,7 +187,12 @@ class FunctionPropertiesUpdater {
static bool isUpdateValid(Function &F, const FunctionPropertiesInfo &FPI,
FunctionAnalysisManager &FAM);
+ DominatorTree &getUpdatedDominatorTree(FunctionAnalysisManager &FAM) const;
+
DenseSet<const BasicBlock *> Successors;
+
+ // Edges we might potentially need to remove from the dominator tree.
+ SmallVector<DominatorTree::UpdateType, 2> DomTreeUpdates;
};
} // namespace llvm
#endif // LLVM_ANALYSIS_FUNCTIONPROPERTIESANALYSIS_H
diff --git a/llvm/lib/Analysis/FunctionPropertiesAnalysis.cpp b/llvm/lib/Analysis/FunctionPropertiesAnalysis.cpp
index 6d6ec6c7b1cc76..c2746e6cecb59b 100644
--- a/llvm/lib/Analysis/FunctionPropertiesAnalysis.cpp
+++ b/llvm/lib/Analysis/FunctionPropertiesAnalysis.cpp
@@ -326,6 +326,20 @@ FunctionPropertiesUpdater::FunctionPropertiesUpdater(
// with the CB BB ('Entry') between which the inlined callee will be pasted.
Successors.insert(succ_begin(&CallSiteBB), succ_end(&CallSiteBB));
+ // the outcome of the inlining may be that some edges get lost (DCEd BBs
+ // because inlining brought some constant, for example). We don't know which
+ // edges will be removed, so we list all of them as potentially removable.
+ // Some BBs have (at this point) duplicate edges. Remove duplicates, otherwise
+ // the DT updater will not apply changes correctly.
+ DenseSet<const BasicBlock *> Inserted;
+ for (auto *Succ : successors(&CallSiteBB))
+ if (Inserted.insert(Succ).second)
+ DomTreeUpdates.emplace_back(DominatorTree::UpdateKind::Delete,
+ const_cast<BasicBlock *>(&CallSiteBB),
+ const_cast<BasicBlock *>(Succ));
+ // Reuse Inserted (which has some allocated capacity at this point) below, if
+ // we have an invoke.
+ Inserted.clear();
// Inlining only handles invoke and calls. If this is an invoke, and inlining
// it pulls another invoke, the original landing pad may get split, so as to
// share its content with other potential users. So the edge up to which we
@@ -336,6 +350,12 @@ FunctionPropertiesUpdater::FunctionPropertiesUpdater(
if (const auto *II = dyn_cast<InvokeInst>(&CB)) {
const auto *UnwindDest = II->getUnwindDest();
Successors.insert(succ_begin(UnwindDest), succ_end(UnwindDest));
+ // Same idea as above, we pretend we lose all these edges.
+ for (auto *Succ : successors(UnwindDest))
+ if (Inserted.insert(Succ).second)
+ DomTreeUpdates.emplace_back(DominatorTree::UpdateKind::Delete,
+ const_cast<BasicBlock *>(UnwindDest),
+ const_cast<BasicBlock *>(Succ));
}
// Exclude the CallSiteBB, if it happens to be its own successor (1-BB loop).
@@ -356,6 +376,30 @@ FunctionPropertiesUpdater::FunctionPropertiesUpdater(
FPI.updateForBB(*BB, -1);
}
+DominatorTree &FunctionPropertiesUpdater::getUpdatedDominatorTree(
+ FunctionAnalysisManager &FAM) const {
+ auto &DT =
+ FAM.getResult<DominatorTreeAnalysis>(const_cast<Function &>(Caller));
+
+ SmallVector<DominatorTree::UpdateType, 2> FinalDomTreeUpdates;
+
+ for (auto &Upd : DomTreeUpdates)
+ FinalDomTreeUpdates.push_back(Upd);
+
+ DenseSet<const BasicBlock *> Inserted;
+ for (auto *Succ : successors(&CallSiteBB))
+ if (Inserted.insert(Succ).second)
+ FinalDomTreeUpdates.push_back({DominatorTree::UpdateKind::Insert,
+ const_cast<BasicBlock *>(&CallSiteBB),
+ const_cast<BasicBlock *>(Succ)});
+
+ DT.applyUpdates(FinalDomTreeUpdates);
+#ifdef EXPENSIVE_CHECKS
+ assert(DT.verify(DominatorTree::VerificationLevel::Full));
+#endif
+ return DT;
+}
+
void FunctionPropertiesUpdater::finish(FunctionAnalysisManager &FAM) const {
// Update feature values from the BBs that were copied from the callee, or
// might have been modified because of inlining. The latter have been
@@ -383,8 +427,7 @@ void FunctionPropertiesUpdater::finish(FunctionAnalysisManager &FAM) const {
// remove E.
SetVector<const BasicBlock *> Reinclude;
SetVector<const BasicBlock *> Unreachable;
- const auto &DT =
- FAM.getResult<DominatorTreeAnalysis>(const_cast<Function &>(Caller));
+ auto &DT = getUpdatedDominatorTree(FAM);
if (&CallSiteBB != &*Caller.begin())
Reinclude.insert(&*Caller.begin());
@@ -427,6 +470,9 @@ void FunctionPropertiesUpdater::finish(FunctionAnalysisManager &FAM) const {
const auto &LI = FAM.getResult<LoopAnalysis>(const_cast<Function &>(Caller));
FPI.updateAggregateStats(Caller, LI);
+#ifdef EXPENSIVE_CHECKS
+ assert(isUpdateValid(Caller, FPI, FAM));
+#endif
}
bool FunctionPropertiesUpdater::isUpdateValid(Function &F,
diff --git a/llvm/lib/Analysis/MLInlineAdvisor.cpp b/llvm/lib/Analysis/MLInlineAdvisor.cpp
index b59aa4810005bc..8bb5efcf1b2ecb 100644
--- a/llvm/lib/Analysis/MLInlineAdvisor.cpp
+++ b/llvm/lib/Analysis/MLInlineAdvisor.cpp
@@ -288,7 +288,6 @@ void MLInlineAdvisor::onSuccessfulInlining(const MLInlineAdvice &Advice,
{
PreservedAnalyses PA = PreservedAnalyses::all();
PA.abandon<FunctionPropertiesAnalysis>();
- PA.abandon<DominatorTreeAnalysis>();
PA.abandon<LoopAnalysis>();
FAM.invalidate(*Caller, PA);
}
diff --git a/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp b/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp
index 3b3823589437a8..d0eb397d6c2c07 100644
--- a/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp
+++ b/llvm/unittests/Analysis/FunctionPropertiesAnalysisTest.cpp
@@ -999,4 +999,71 @@ declare <4 x ptr> @f4()
EXPECT_EQ(DetailedF1Properties.CallReturnsVectorPointerCount, 1);
EnableDetailedFunctionProperties.setValue(false);
}
+
+TEST_F(FunctionPropertiesAnalysisTest, ReAddEdges) {
+ LLVMContext C;
+ std::unique_ptr<Module> M = makeLLVMModule(C, R"IR(
+define hidden void @f1(ptr noundef %destatep, i32 noundef %offset, i8 noundef zeroext %byte1) {
+entry:
+ %cmp = icmp eq i8 %byte1, 0
+ br i1 %cmp, label %if.then, label %if.else
+
+if.then: ; preds = %entry
+ call fastcc void @f2(ptr noundef %destatep, i32 noundef 37, i32 noundef 600)
+ %and = and i32 %offset, 3
+ switch i32 %and, label %default.unreachable [
+ i32 0, label %sw.bb
+ i32 1, label %sw.bb1
+ i32 2, label %sw.bb1
+ i32 3, label %if.end
+ ]
+
+sw.bb: ; preds = %if.then
+ call fastcc void @f2(ptr noundef %destatep, i32 noundef 57, i32 noundef 600)
+ br label %if.end
+
+sw.bb1: ; preds = %if.then, %if.then
+ call fastcc void @f2(ptr noundef %destatep, i32 noundef 56, i32 noundef 600) #34
+ br label %if.end
+
+default.unreachable: ; preds = %if.then
+ unreachable
+
+if.else: ; preds = %entry
+ call fastcc void @f2(ptr noundef %destatep, i32 noundef 56, i32 noundef 600)
+ br label %if.end
+
+if.end: ; preds = %sw.bb, %sw.bb1, %if.then, %if.else
+ ret void
+}
+
+define internal fastcc void @f2(ptr nocapture noundef %destatep, i32 noundef %r_enc, i32 noundef %whack) {
+entry:
+ %enc_prob = getelementptr inbounds nuw i8, ptr %destatep, i32 512
+ %arrayidx = getelementptr inbounds [67 x i32], ptr %enc_prob, i32 0, i32 %r_enc
+ %0 = load i32, ptr %arrayidx, align 4
+ %sub = sub nsw i32 %0, %whack
+ store i32 %sub, ptr %arrayidx, align 4
+ ret void
+}
+ )IR");
+ auto *F1 = M->getFunction("f1");
+ auto *F2 = M->getFunction("f2");
+ auto *CB = [&]() -> CallBase * {
+ for (auto &BB : *F1)
+ for (auto &I : BB)
+ if (auto *CB = dyn_cast<CallBase>(&I);
+ CB && CB->getCalledFunction() && CB->getCalledFunction() == F2)
+ return CB;
+ return nullptr;
+ }();
+ ASSERT_NE(CB, nullptr);
+ auto FPI = buildFPI(*F1);
+ FunctionPropertiesUpdater FPU(FPI, *CB);
+ InlineFunctionInfo IFI;
+ auto IR = llvm::InlineFunction(*CB, IFI);
+ EXPECT_TRUE(IR.isSuccess());
+ invalidate(*F1);
+ EXPECT_TRUE(FPU.finishAndTest(FAM));
+}
} // end anonymous namespace
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✅ With the latest revision this PR passed the C/C++ code formatter. |
mtrofin
deleted the
users/mtrofin/08-27-reapply_nfc_mlgo_incrementally_update_dominatortreeanalysis_in_functionpropertiesanalysis_104867_
branch
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/72/builds/2771 Here is the relevant piece of the build log for the reference |
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/66/builds/3247 Here is the relevant piece of the build log for the reference |
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Reverts c992690.
The problem is that if there is a sequence "{delete A->B} {delete A->B} {insert A->B}" the net result is "{delete A->B}", which is not what we want.
Duplicate successors may happen in cases like switch statements (as shown in the unit test).
The fix is to sanitize the list of deletes, just like we do for inserts.