From 505091a8f2ae676838dc33e429d81e3d2555edf4 Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Wed, 14 Nov 2018 10:04:30 +0000 Subject: [PATCH] Recommit r346483: [CallSiteSplitting] Only record conditions up to the IDom(call site). The underlying problem causing the expensive-check failure was fixed in rL346769. llvm-svn: 346843 --- llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp | 39 ++++++++++++------- llvm/test/Other/new-pm-lto-defaults.ll | 4 +- llvm/test/Other/opt-O3-pipeline.ll | 1 + .../CallSiteSplitting/callsite-split-or-phi.ll | 45 +++++++++++++++++----- 4 files changed, 64 insertions(+), 25 deletions(-) diff --git a/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp b/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp index fc7450a..2be4160 100644 --- a/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp +++ b/llvm/lib/Transforms/Scalar/CallSiteSplitting.cpp @@ -149,14 +149,14 @@ static void recordCondition(CallSite CS, BasicBlock *From, BasicBlock *To, /// Record ICmp conditions relevant to any argument in CS following Pred's /// single predecessors. If there are conflicting conditions along a path, like -/// x == 1 and x == 0, the first condition will be used. +/// x == 1 and x == 0, the first condition will be used. We stop once we reach +/// an edge to StopAt. static void recordConditions(CallSite CS, BasicBlock *Pred, - ConditionsTy &Conditions) { - recordCondition(CS, Pred, CS.getInstruction()->getParent(), Conditions); + ConditionsTy &Conditions, BasicBlock *StopAt) { BasicBlock *From = Pred; BasicBlock *To = Pred; SmallPtrSet Visited; - while (!Visited.count(From->getSinglePredecessor()) && + while (To != StopAt && !Visited.count(From->getSinglePredecessor()) && (From = From->getSinglePredecessor())) { recordCondition(CS, From, To, Conditions); Visited.insert(From); @@ -453,15 +453,27 @@ static PredsWithCondsTy shouldSplitOnPHIPredicatedArgument(CallSite CS) { // Checks if any of the arguments in CS are predicated in a predecessor and // returns a list of predecessors with the conditions that hold on their edges // to CS. -static PredsWithCondsTy shouldSplitOnPredicatedArgument(CallSite CS) { +static PredsWithCondsTy shouldSplitOnPredicatedArgument(CallSite CS, + DomTreeUpdater &DTU) { auto Preds = getTwoPredecessors(CS.getInstruction()->getParent()); if (Preds[0] == Preds[1]) return {}; + // We can stop recording conditions once we reached the immediate dominator + // for the block containing the call site. Conditions in predecessors of the + // that node will be the same for all paths to the call site and splitting + // is not beneficial. + assert(DTU.hasDomTree() && "We need a DTU with a valid DT!"); + auto *CSDTNode = DTU.getDomTree().getNode(CS.getInstruction()->getParent()); + BasicBlock *StopAt = CSDTNode ? CSDTNode->getIDom()->getBlock() : nullptr; + SmallVector, 2> PredsCS; for (auto *Pred : make_range(Preds.rbegin(), Preds.rend())) { ConditionsTy Conditions; - recordConditions(CS, Pred, Conditions); + // Record condition on edge BB(CS) <- Pred + recordCondition(CS, Pred, CS.getInstruction()->getParent(), Conditions); + // Record conditions following Pred's single predecessors. + recordConditions(CS, Pred, Conditions, StopAt); PredsCS.push_back({Pred, Conditions}); } @@ -479,7 +491,7 @@ static bool tryToSplitCallSite(CallSite CS, TargetTransformInfo &TTI, if (!CS.arg_size() || !canSplitCallSite(CS, TTI)) return false; - auto PredsWithConds = shouldSplitOnPredicatedArgument(CS); + auto PredsWithConds = shouldSplitOnPredicatedArgument(CS, DTU); if (PredsWithConds.empty()) PredsWithConds = shouldSplitOnPHIPredicatedArgument(CS); if (PredsWithConds.empty()) @@ -490,9 +502,9 @@ static bool tryToSplitCallSite(CallSite CS, TargetTransformInfo &TTI, } static bool doCallSiteSplitting(Function &F, TargetLibraryInfo &TLI, - TargetTransformInfo &TTI, DominatorTree *DT) { + TargetTransformInfo &TTI, DominatorTree &DT) { - DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy); + DomTreeUpdater DTU(&DT, DomTreeUpdater::UpdateStrategy::Lazy); bool Changed = false; for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE;) { BasicBlock &BB = *BI++; @@ -537,6 +549,7 @@ struct CallSiteSplittingLegacyPass : public FunctionPass { void getAnalysisUsage(AnalysisUsage &AU) const override { AU.addRequired(); AU.addRequired(); + AU.addRequired(); AU.addPreserved(); FunctionPass::getAnalysisUsage(AU); } @@ -547,9 +560,8 @@ struct CallSiteSplittingLegacyPass : public FunctionPass { auto &TLI = getAnalysis().getTLI(); auto &TTI = getAnalysis().getTTI(F); - auto *DTWP = getAnalysisIfAvailable(); - return doCallSiteSplitting(F, TLI, TTI, - DTWP ? &DTWP->getDomTree() : nullptr); + auto &DT = getAnalysis().getDomTree(); + return doCallSiteSplitting(F, TLI, TTI, DT); } }; } // namespace @@ -559,6 +571,7 @@ INITIALIZE_PASS_BEGIN(CallSiteSplittingLegacyPass, "callsite-splitting", "Call-site splitting", false, false) INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass) INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass) +INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) INITIALIZE_PASS_END(CallSiteSplittingLegacyPass, "callsite-splitting", "Call-site splitting", false, false) FunctionPass *llvm::createCallSiteSplittingPass() { @@ -569,7 +582,7 @@ PreservedAnalyses CallSiteSplittingPass::run(Function &F, FunctionAnalysisManager &AM) { auto &TLI = AM.getResult(F); auto &TTI = AM.getResult(F); - auto *DT = AM.getCachedResult(F); + auto &DT = AM.getResult(F); if (!doCallSiteSplitting(F, TLI, TTI, DT)) return PreservedAnalyses::all(); diff --git a/llvm/test/Other/new-pm-lto-defaults.ll b/llvm/test/Other/new-pm-lto-defaults.ll index 03f4804..ee2f041 100644 --- a/llvm/test/Other/new-pm-lto-defaults.ll +++ b/llvm/test/Other/new-pm-lto-defaults.ll @@ -38,13 +38,13 @@ ; CHECK-O2-NEXT: Running pass: CallSiteSplittingPass on foo ; CHECK-O2-NEXT: Running analysis: TargetLibraryAnalysis on foo ; CHECK-O2-NEXT: Running analysis: TargetIRAnalysis on foo +; CHECK-O2-NEXT: Running analysis: DominatorTreeAnalysis on foo ; CHECK-O2-NEXT: Finished llvm::Function pass manager run. ; CHECK-O2-NEXT: PGOIndirectCallPromotion ; CHECK-O2-NEXT: Running analysis: ProfileSummaryAnalysis ; CHECK-O2-NEXT: Running analysis: OptimizationRemarkEmitterAnalysis ; CHECK-O2-NEXT: Running pass: IPSCCPPass -; CHECK-O2-DAG: Running analysis: AssumptionAnalysis on foo -; CHECK-O2-DAG: Running analysis: DominatorTreeAnalysis on foo +; CHECK-O2-NEXT: Running analysis: AssumptionAnalysis on foo ; CHECK-O2-NEXT: Running pass: CalledValuePropagationPass ; CHECK-O-NEXT: Running pass: ModuleToPostOrderCGSCCPassAdaptor<{{.*}}PostOrderFunctionAttrsPass> ; CHECK-O-NEXT: Running analysis: InnerAnalysisManagerProxy<{{.*}}SCC diff --git a/llvm/test/Other/opt-O3-pipeline.ll b/llvm/test/Other/opt-O3-pipeline.ll index 33033fe..51b6a6d 100644 --- a/llvm/test/Other/opt-O3-pipeline.ll +++ b/llvm/test/Other/opt-O3-pipeline.ll @@ -28,6 +28,7 @@ ; CHECK-NEXT: Force set function attributes ; CHECK-NEXT: Infer set function attributes ; CHECK-NEXT: FunctionPass Manager +; CHECK-NEXT: Dominator Tree Construction ; CHECK-NEXT: Call-site splitting ; CHECK-NEXT: Interprocedural Sparse Conditional Constant Propagation ; CHECK-NEXT: Unnamed pass: implement Pass::getPassName() diff --git a/llvm/test/Transforms/CallSiteSplitting/callsite-split-or-phi.ll b/llvm/test/Transforms/CallSiteSplitting/callsite-split-or-phi.ll index d5f31f9..cd2edb1 100644 --- a/llvm/test/Transforms/CallSiteSplitting/callsite-split-or-phi.ll +++ b/llvm/test/Transforms/CallSiteSplitting/callsite-split-or-phi.ll @@ -37,9 +37,9 @@ End: ;CHECK-LABEL: @test_eq_eq_eq ;CHECK-LABEL: Header2.split: -;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* null, i32 %v, i32 10) +;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* %a, i32 %v, i32 10) ;CHECK-LABEL: TBB.split: -;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* null, i32 1, i32 %p) +;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* %a, i32 1, i32 %p) ;CHECK-LABEL: Tail ;CHECK: %[[MERGED:.*]] = phi i32 [ %[[CALL1]], %Header2.split ], [ %[[CALL2]], %TBB.split ] ;CHECK: ret i32 %[[MERGED]] @@ -123,14 +123,14 @@ End: ;CHECK-LABEL: Header2.split: ;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* nonnull %a, i32 %v, i32 10) ;CHECK-LABEL: TBB.split: -;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* nonnull %a, i32 %v, i32 %p) +;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* %a, i32 %v, i32 %p) ;CHECK-LABEL: Tail ;CHECK: %[[MERGED:.*]] = phi i32 [ %[[CALL1]], %Header2.split ], [ %[[CALL2]], %TBB.split ] ;CHECK: ret i32 %[[MERGED]] define i32 @test_ne_eq_ne(i32* %a, i32 %v, i32 %p) { Header: %tobool1 = icmp ne i32* %a, null - br i1 %tobool1, label %Header2, label %End + br i1 %tobool1, label %Header2, label %TBB Header2: %tobool2 = icmp eq i32 %p, 10 @@ -178,14 +178,14 @@ End: ;CHECK-LABEL: Header2.split: ;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* nonnull %a, i32 %v, i32 %p) ;CHECK-LABEL: TBB.split: -;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* nonnull %a, i32 %v, i32 %p) +;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* %a, i32 %v, i32 %p) ;CHECK-LABEL: Tail ;CHECK: %[[MERGED:.*]] = phi i32 [ %[[CALL1]], %Header2.split ], [ %[[CALL2]], %TBB.split ] ;CHECK: ret i32 %[[MERGED]] define i32 @test_ne_ne_ne_constrain_same_pointer_arg(i32* %a, i32 %v, i32 %p, i32* %a2, i32* %a3) { Header: %tobool1 = icmp ne i32* %a, null - br i1 %tobool1, label %Header2, label %End + br i1 %tobool1, label %Header2, label %TBB Header2: %tobool2 = icmp ne i32* %a, %a2 @@ -235,14 +235,14 @@ End: ;CHECK-LABEL: Header2.split: ;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* nonnull %a, i32 %v, i32 10) ;CHECK-LABEL: TBB.split: -;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* nonnull %a, i32 1, i32 %p) +;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* %a, i32 1, i32 %p) ;CHECK-LABEL: Tail ;CHECK: %[[MERGED:.*]] = phi i32 [ %[[CALL1]], %Header2.split ], [ %[[CALL2]], %TBB.split ] ;CHECK: ret i32 %[[MERGED]] define i32 @test_eq_eq_eq_untaken(i32* %a, i32 %v, i32 %p) { Header: %tobool1 = icmp eq i32* %a, null - br i1 %tobool1, label %End, label %Header2 + br i1 %tobool1, label %TBB, label %Header2 Header2: %tobool2 = icmp eq i32 %p, 10 @@ -290,14 +290,14 @@ End: ;CHECK-LABEL: Header2.split: ;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* null, i32 %v, i32 10) ;CHECK-LABEL: TBB.split: -;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* null, i32 %v, i32 %p) +;CHECK: %[[CALL2:.*]] = call i32 @callee(i32* %a, i32 %v, i32 %p) ;CHECK-LABEL: Tail ;CHECK: %[[MERGED:.*]] = phi i32 [ %[[CALL1]], %Header2.split ], [ %[[CALL2]], %TBB.split ] ;CHECK: ret i32 %[[MERGED]] define i32 @test_ne_eq_ne_untaken(i32* %a, i32 %v, i32 %p) { Header: %tobool1 = icmp ne i32* %a, null - br i1 %tobool1, label %End, label %Header2 + br i1 %tobool1, label %TBB, label %Header2 Header2: %tobool2 = icmp eq i32 %p, 10 @@ -489,6 +489,31 @@ End: ret i32 %v } +;CHECK-LABEL: @test_cond_no_effect +;CHECK-NOT: Header.split: +;CHECK-NOT: TBB.split: +;CHECK-LABEL: Tail: +;CHECK: %r = call i32 @callee(i32* %a, i32 %v, i32 0) +;CHECK: ret i32 %r +define i32 @test_cond_no_effect(i32* %a, i32 %v) { +Entry: + %tobool1 = icmp eq i32* %a, null + br i1 %tobool1, label %Header, label %End + +Header: + br i1 undef, label %Tail, label %TBB + +TBB: + br i1 undef, label %Tail, label %End + +Tail: + %r = call i32 @callee(i32* %a, i32 %v, i32 0) + ret i32 %r + +End: + ret i32 %v +} + ;CHECK-LABEL: @test_unreachable ;CHECK-LABEL: Header.split: ;CHECK: %[[CALL1:.*]] = call i32 @callee(i32* %a, i32 %v, i32 10) -- 2.7.4