From c4f1b3144184e4c276a7e7c801cbcd4ac3c573ba Mon Sep 17 00:00:00 2001 From: Florian Hahn Date: Mon, 14 Sep 2020 15:51:17 +0100 Subject: [PATCH] [MemorySSA] Make sure PerformedPhiTrans is updated for each visited def. 1ce82015f6d0 added a fix to restrict phi optimizations after phi translations. But the current use of performedPhiTranslation only checked whether phi translation happened for the first iterator and missed cases where phi translations happens at subsequent iterators/upwards defs. This patch changes upward_defs_iteartor to take a pointer to a bool, so we can easily ensure the final value includes all visited defs, while still being able to conveniently use it with make_range & co. --- llvm/include/llvm/Analysis/MemorySSA.h | 20 ++++++++++--------- llvm/lib/Analysis/MemorySSA.cpp | 4 ++-- .../Analysis/MemorySSA/phi-translation.ll | 7 +++---- 3 files changed, 16 insertions(+), 15 deletions(-) diff --git a/llvm/include/llvm/Analysis/MemorySSA.h b/llvm/include/llvm/Analysis/MemorySSA.h index 3ec09e8c0a45..5878b53fa372 100644 --- a/llvm/include/llvm/Analysis/MemorySSA.h +++ b/llvm/include/llvm/Analysis/MemorySSA.h @@ -1181,9 +1181,11 @@ class upward_defs_iterator using BaseT = upward_defs_iterator::iterator_facade_base; public: - upward_defs_iterator(const MemoryAccessPair &Info, DominatorTree *DT) + upward_defs_iterator(const MemoryAccessPair &Info, DominatorTree *DT, + bool *PerformedPhiTranslation = nullptr) : DefIterator(Info.first), Location(Info.second), - OriginalAccess(Info.first), DT(DT) { + OriginalAccess(Info.first), DT(DT), + PerformedPhiTranslation(PerformedPhiTranslation) { CurrentPair.first = nullptr; WalkingPhi = Info.first && isa(Info.first); @@ -1214,8 +1216,6 @@ public: BasicBlock *getPhiArgBlock() const { return DefIterator.getPhiArgBlock(); } - bool performedPhiTranslation() const { return PerformedPhiTranslation; } - private: void fillInCurrentPair() { CurrentPair.first = *DefIterator; @@ -1228,7 +1228,8 @@ private: false)) { if (Translator.getAddr() != Location.Ptr) { CurrentPair.second = Location.getWithNewPtr(Translator.getAddr()); - PerformedPhiTranslation = true; + if (PerformedPhiTranslation) + *PerformedPhiTranslation = true; return; } } else { @@ -1245,12 +1246,13 @@ private: MemoryAccess *OriginalAccess = nullptr; DominatorTree *DT = nullptr; bool WalkingPhi = false; - bool PerformedPhiTranslation = false; + bool *PerformedPhiTranslation = nullptr; }; -inline upward_defs_iterator upward_defs_begin(const MemoryAccessPair &Pair, - DominatorTree &DT) { - return upward_defs_iterator(Pair, &DT); +inline upward_defs_iterator +upward_defs_begin(const MemoryAccessPair &Pair, DominatorTree &DT, + bool *PerformedPhiTranslation = nullptr) { + return upward_defs_iterator(Pair, &DT, PerformedPhiTranslation); } inline upward_defs_iterator upward_defs_end() { return upward_defs_iterator(); } diff --git a/llvm/lib/Analysis/MemorySSA.cpp b/llvm/lib/Analysis/MemorySSA.cpp index f54f04460a4d..14fa11988362 100644 --- a/llvm/lib/Analysis/MemorySSA.cpp +++ b/llvm/lib/Analysis/MemorySSA.cpp @@ -603,13 +603,13 @@ template class ClobberWalker { void addSearches(MemoryPhi *Phi, SmallVectorImpl &PausedSearches, ListIndex PriorNode) { - auto UpwardDefsBegin = upward_defs_begin({Phi, Paths[PriorNode].Loc}, DT); + auto UpwardDefsBegin = upward_defs_begin({Phi, Paths[PriorNode].Loc}, DT, + &PerformedPhiTranslation); auto UpwardDefs = make_range(UpwardDefsBegin, upward_defs_end()); for (const MemoryAccessPair &P : UpwardDefs) { PausedSearches.push_back(Paths.size()); Paths.emplace_back(P.second, P.first, PriorNode); } - PerformedPhiTranslation |= UpwardDefsBegin.performedPhiTranslation(); } /// Represents a search that terminated after finding a clobber. This clobber diff --git a/llvm/test/Analysis/MemorySSA/phi-translation.ll b/llvm/test/Analysis/MemorySSA/phi-translation.ll index 0844760327b1..1274e365066d 100644 --- a/llvm/test/Analysis/MemorySSA/phi-translation.ll +++ b/llvm/test/Analysis/MemorySSA/phi-translation.ll @@ -384,10 +384,9 @@ define void @dont_merge_noalias_complex_2(i32 %arg, i32 %arg1) { ; CHECK-NEXT: call void @init([32 x i32]* %tmp) ; CHECK-LABEL: loop.1.header: -; CHECK-NEXT: ; 4 = MemoryPhi({entry,1},{loop.1.latch,3}) -; NOLIMIT: ; MemoryUse(1) MayAlias -; LIMIT: ; MemoryUse(4) MayAlias -; CHECK-NEXT: %l.1 = load i32, i32* %p.1, align 4 +; CHECK-NEXT: ; 4 = MemoryPhi({entry,1},{loop.1.latch,3}) +; CHECK: ; MemoryUse(4) MayAlias +; CHECK-NEXT: %l.1 = load i32, i32* %p.1, align 4 ; CHECK-LABEL: loop.1.latch: ; CHECK-NEXT: ; 3 = MemoryPhi({loop.1.header,4},{storebb,2})