Merge pull request swiftlang#20819 from gottesmm/pr-f46c6ad2fee1ea70f7b25a8f6a89ab7af28c1404

[ownership] Ban ValueOwnershipKind::Any in preparation for eliminated ValueOwnershipKind::Trivial

Author: gottesmm

include/swift/SIL/SILUndef.h

@@ -17,25 +17,29 @@
 #include "swift/SIL/SILValue.h"
 
 namespace swift {
+
 class SILArgument;
 class SILInstruction;
 class SILModule;
 
 class SILUndef : public ValueBase {
-  void operator=(const SILArgument &) = delete;
-
-  void operator delete(void *Ptr, size_t) SWIFT_DELETE_OPERATOR_DELETED;
+  ValueOwnershipKind ownershipKind;
 
-  SILUndef(SILType Ty)
-      : ValueBase(ValueKind::SILUndef, Ty, IsRepresentative::Yes) {}
+  SILUndef(SILType type, SILModule &m);
 
 public:
+  void operator=(const SILArgument &) = delete;
+  void operator delete(void *, size_t) SWIFT_DELETE_OPERATOR_DELETED;
+
+  static SILUndef *get(SILType ty, SILModule &m);
+  static SILUndef *get(SILType ty, SILModule *m) { return get(ty, *m); }
 
-  static SILUndef *get(SILType Ty, SILModule *M);
-  static SILUndef *get(SILType Ty, SILModule &M) { return get(Ty, &M); }
+  template <class OwnerTy>
+  static SILUndef *getSentinelValue(SILType type, SILModule &m, OwnerTy owner) {
+    return new (*owner) SILUndef(type, m);
+  }
 
-  template<class OwnerTy>
-  static SILUndef *getSentinelValue(SILType Ty, OwnerTy Owner) { return new (*Owner) SILUndef(Ty); }
+  ValueOwnershipKind getOwnershipKind() const { return ownershipKind; }
 
   static bool classof(const SILArgument *) = delete;
   static bool classof(const SILInstruction *) = delete;

include/swift/SILOptimizer/Utils/SILSSAUpdater.h

@@ -51,12 +51,15 @@ class SILSSAUpdater {
   // If not null updated with inserted 'phi' nodes (SILArgument).
   SmallVectorImpl<SILPhiArgument *> *InsertedPHIs;
 
+  SILModule &M;
+
   // Not copyable.
   void operator=(const SILSSAUpdater &) = delete;
   SILSSAUpdater(const SILSSAUpdater &) = delete;
 
 public:
   explicit SILSSAUpdater(
+      SILModule &M,
       SmallVectorImpl<SILPhiArgument *> *InsertedPHIs = nullptr);
   ~SILSSAUpdater();
 

lib/SIL/CMakeLists.txt

@@ -37,6 +37,7 @@ add_swift_host_library(swiftSIL STATIC
   SILProfiler.cpp
   SILSuccessor.cpp
   SILType.cpp
+  SILUndef.cpp
   SILValue.cpp
   SILVerifier.cpp
   SILOwnershipVerifier.cpp

lib/SIL/SIL.cpp

@@ -30,14 +30,6 @@
 
 using namespace swift;
 
-SILUndef *SILUndef::get(SILType Ty, SILModule *M) {
-  // Unique these.
-  SILUndef *&Entry = M->UndefValues[Ty];
-  if (Entry == nullptr)
-    Entry = new (*M) SILUndef(Ty);
-  return Entry;
-}
-
 FormalLinkage swift::getDeclLinkage(const ValueDecl *D) {
   const DeclContext *fileContext = D->getDeclContext()->getModuleScopeContext();
 

lib/SIL/SILOwnershipVerifier.cpp

@@ -669,9 +669,6 @@ void SILInstruction::verifyOperandOwnership() const {
       continue;
     SILValue opValue = op.get();
 
-    // Skip any SILUndef that we see.
-    if (isa<SILUndef>(opValue))
-      continue;
     auto operandOwnershipKindMap = op.getOwnershipKindMap();
     auto valueOwnershipKind = opValue.getOwnershipKind();
     if (operandOwnershipKindMap.canAcceptKind(valueOwnershipKind))
@@ -702,11 +699,6 @@ void SILValue::verifyOwnership(SILModule &mod,
   if (DisableOwnershipVerification)
     return;
 
-  // If we are SILUndef, just bail. SILUndef can pair with anything. Any uses of
-  // the SILUndef will make sure that the matching checks out.
-  if (isa<SILUndef>(*this))
-    return;
-
   // Since we do not have SILUndef, we now know that getFunction() should return
   // a real function. Assert in case this assumption is no longer true.
   SILFunction *f = (*this)->getFunction();
@@ -717,6 +709,8 @@ void SILValue::verifyOwnership(SILModule &mod,
   if (!f->hasQualifiedOwnership() || !f->shouldVerifyOwnership())
     return;
 
+  assert(getOwnershipKind() != ValueOwnershipKind::Any &&
+         "No values should have any ownership anymore");
   ErrorBehaviorKind errorBehavior;
   if (IsSILOwnershipVerifierTestingEnabled) {
     errorBehavior = ErrorBehaviorKind::PrintMessageAndReturnFalse;
@@ -743,11 +737,6 @@ bool OwnershipChecker::checkValue(SILValue value) {
   lifetimeEndingUsers.clear();
   liveBlocks.clear();
 
-  // If we are SILUndef, just bail. SILUndef can pair with anything. Any uses of
-  // the SILUndef will make sure that the matching checks out.
-  if (isa<SILUndef>(value))
-    return false;
-
   // Since we do not have SILUndef, we now know that getFunction() should return
   // a real function. Assert in case this assumption is no longer true.
   SILFunction *f = value->getFunction();

lib/SIL/SILUndef.cpp

@@ -0,0 +1,34 @@
+//===--- SILUndef.cpp -----------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#include "swift/SIL/SILUndef.h"
+#include "swift/SIL/SILModule.h"
+
+using namespace swift;
+
+static ValueOwnershipKind getOwnershipKindForUndef(SILType type, SILModule &m) {
+  if (type.isTrivial(m))
+    return ValueOwnershipKind::Trivial;
+  return ValueOwnershipKind::Owned;
+}
+
+SILUndef::SILUndef(SILType type, SILModule &m)
+    : ValueBase(ValueKind::SILUndef, type, IsRepresentative::Yes),
+      ownershipKind(getOwnershipKindForUndef(type, m)) {}
+
+SILUndef *SILUndef::get(SILType ty, SILModule &m) {
+  // Unique these.
+  SILUndef *&entry = m.UndefValues[ty];
+  if (entry == nullptr)
+    entry = new (m) SILUndef(ty, m);
+  return entry;
+}

lib/SIL/ValueOwnership.cpp

@@ -280,8 +280,8 @@ ValueOwnershipKindClassifier::visitUncheckedOwnershipConversionInst(
   return I->getConversionOwnershipKind();
 }
 
-ValueOwnershipKind ValueOwnershipKindClassifier::visitSILUndef(SILUndef *Arg) {
-  return ValueOwnershipKind::Any;
+ValueOwnershipKind ValueOwnershipKindClassifier::visitSILUndef(SILUndef *arg) {
+  return arg->getOwnershipKind();
 }
 
 ValueOwnershipKind

lib/SILOptimizer/LoopTransforms/COWArrayOpt.cpp

@@ -1619,7 +1619,7 @@ class RegionCloner : public SILCloner<RegionCloner> {
   }
 
   void updateSSAForm() {
-    SILSSAUpdater SSAUp;
+    SILSSAUpdater SSAUp(StartBB->getParent()->getModule());
     for (auto *origBB : originalPreorderBlocks()) {
       // Update outside used phi values.
       for (auto *arg : origBB->getArguments())

lib/SILOptimizer/LoopTransforms/LoopRotate.cpp

@@ -174,7 +174,7 @@ rewriteNewLoopEntryCheckBlock(SILBasicBlock *Header,
                               SILBasicBlock *EntryCheckBlock,
                         const llvm::DenseMap<ValueBase *, SILValue> &ValueMap) {
   SmallVector<SILPhiArgument *, 4> InsertedPHIs;
-  SILSSAUpdater Updater(&InsertedPHIs);
+  SILSSAUpdater Updater(Header->getParent()->getModule(), &InsertedPHIs);
 
   // Fix PHIs (incoming arguments).
   for (auto *Arg : Header->getArguments())

lib/SILOptimizer/LoopTransforms/LoopUnroll.cpp

@@ -305,9 +305,9 @@ void LoopCloner::collectLoopLiveOutValues(
 }
 
 static void
-updateSSA(SILLoop *Loop,
+updateSSA(SILModule &M, SILLoop *Loop,
           DenseMap<SILValue, SmallVector<SILValue, 8>> &LoopLiveOutValues) {
-  SILSSAUpdater SSAUp;
+  SILSSAUpdater SSAUp(M);
   for (auto &MapEntry : LoopLiveOutValues) {
     // Collect out of loop uses of this value.
     auto OrigValue = MapEntry.first;
@@ -335,6 +335,7 @@ static bool tryToUnrollLoop(SILLoop *Loop) {
   auto *Preheader = Loop->getLoopPreheader();
   if (!Preheader)
     return false;
+  SILModule &M = Preheader->getParent()->getModule();
 
   auto *Latch = Loop->getLoopLatch();
   if (!Latch)
@@ -409,7 +410,7 @@ static bool tryToUnrollLoop(SILLoop *Loop) {
   }
 
   // Fixup SSA form for loop values used outside the loop.
-  updateSSA(Loop, LoopLiveOutValues);
+  updateSSA(M, Loop, LoopLiveOutValues);
   return true;
 }