diff options
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp | 25 | ||||
| -rw-r--r-- | llvm/test/Transforms/LoopLoadElim/pr47457.ll | 2 |
2 files changed, 21 insertions, 6 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp b/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp index 3b706956..e8473d6 100644 --- a/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp +++ b/llvm/lib/Transforms/Scalar/LoopLoadElimination.cpp @@ -486,7 +486,6 @@ public: // Filter the candidates further. SmallVector<StoreToLoadForwardingCandidate, 4> Candidates; - unsigned NumForwarding = 0; for (const StoreToLoadForwardingCandidate &Cand : StoreToLoadDependences) { LLVM_DEBUG(dbgs() << "Candidate " << Cand); @@ -506,12 +505,17 @@ public: if (!Cand.isDependenceDistanceOfOne(PSE, L)) continue; - ++NumForwarding; + assert(isa<SCEVAddRecExpr>(PSE.getSCEV(Cand.Load->getPointerOperand())) && + "Loading from something other than indvar?"); + assert( + isa<SCEVAddRecExpr>(PSE.getSCEV(Cand.Store->getPointerOperand())) && + "Storing to something other than indvar?"); + + Candidates.push_back(Cand); LLVM_DEBUG( dbgs() - << NumForwarding + << Candidates.size() << ". Valid store-to-load forwarding across the loop backedge\n"); - Candidates.push_back(Cand); } if (Candidates.empty()) return false; @@ -563,6 +567,17 @@ public: LV.setAliasChecks(std::move(Checks)); LV.setSCEVChecks(LAI.getPSE().getUnionPredicate()); LV.versionLoop(); + + // After versioning, some of the candidates' pointers could stop being + // SCEVAddRecs. We need to filter them out. + auto NoLongerGoodCandidate = [this]( + const StoreToLoadForwardingCandidate &Cand) { + return !isa<SCEVAddRecExpr>( + PSE.getSCEV(Cand.Load->getPointerOperand())) || + !isa<SCEVAddRecExpr>( + PSE.getSCEV(Cand.Store->getPointerOperand())); + }; + llvm::erase_if(Candidates, NoLongerGoodCandidate); } // Next, propagate the value stored by the store to the users of the load. @@ -571,7 +586,7 @@ public: "storeforward"); for (const auto &Cand : Candidates) propagateStoredValueToLoadUsers(Cand, SEE); - NumLoopLoadEliminted += NumForwarding; + NumLoopLoadEliminted += Candidates.size(); return true; } diff --git a/llvm/test/Transforms/LoopLoadElim/pr47457.ll b/llvm/test/Transforms/LoopLoadElim/pr47457.ll index 1b10294..a58be5a 100644 --- a/llvm/test/Transforms/LoopLoadElim/pr47457.ll +++ b/llvm/test/Transforms/LoopLoadElim/pr47457.ll @@ -1,11 +1,11 @@ ; RUN: opt -loop-load-elim -S %s | FileCheck %s ; RUN: opt -passes=loop-load-elim -S %s | FileCheck %s ; REQUIRES: asserts -; XFAIL: * target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128-ni:1-p2:32:8:8:32-ni:2" target triple = "x86_64-unknown-linux-gnu" +; Make sure it does not crash with assert. define void @test() { ; CHECK-LABEL: test |