Merge pull request #3456 from swiftix/cse-of-open-existentials

swiftix · web-flow · commit 865b23a06208 · 2016-07-14T08:22:48.000-07:00
[sil-cse] Add CSE support for open_existential_ref
diff --git a/include/swift/SIL/SILInstruction.h b/include/swift/SIL/SILInstruction.h
@@ -178,6 +178,10 @@ class SILInstruction : public ValueBase,public llvm::ilist_node<SILInstruction>{
   /// Return the array of opened archetypes operands for this instruction.
   MutableArrayRef<Operand> getOpenedArchetypeOperands();
 
+  /// Returns true if a given kind of instruciton may have opened archetype
+  /// operands.
+  bool mayHaveOpenedArchetypeOperands() const;
+
   unsigned getNumOperands() const { return getAllOperands().size(); }
 
   unsigned getNumOpenedArchetypeOperands() const {
diff --git a/lib/SIL/SILInstruction.cpp b/lib/SIL/SILInstruction.cpp
@@ -620,6 +620,10 @@ namespace {
     }
 
     bool visitMarkDependenceInst(const MarkDependenceInst *RHS) {
+       return true;
+    }
+
+    bool visitOpenExistentialRefInst(const OpenExistentialRefInst *RHS) {
       return true;
     }
 
@@ -704,6 +708,23 @@ namespace {
         return {};                                                             \
       return I->getOpenedArchetypeOperands();                                 \
     }
+#include "swift/SIL/SILNodes.def"
+  };
+
+  class MayHaveOpenedArchetypeOperandsAccessor
+      : public SILVisitor<MayHaveOpenedArchetypeOperandsAccessor,
+                          bool> {
+  public:
+#define VALUE(CLASS, PARENT)                                                   \
+  bool visit##CLASS(const CLASS *I) {                                          \
+    llvm_unreachable("accessing non-instruction " #CLASS);                     \
+  }
+#define INST(CLASS, PARENT, MEMBEHAVIOR, RELEASINGBEHAVIOR)                    \
+  bool visit##CLASS(const CLASS *I) {                                          \
+    return IMPLEMENTS_METHOD(CLASS, SILInstruction,                            \
+                             getOpenedArchetypeOperands,                       \
+                             ArrayRef<Operand>() const);                       \
+  }
 #include "swift/SIL/SILNodes.def"
   };
 } // end anonymous namespace
@@ -725,6 +746,11 @@ MutableArrayRef<Operand> SILInstruction::getOpenedArchetypeOperands() {
   return OpenedArchetypeOperandsMutableAccessor().visit(this);
 }
 
+bool SILInstruction::mayHaveOpenedArchetypeOperands() const {
+  return MayHaveOpenedArchetypeOperandsAccessor().visit(
+      const_cast<SILInstruction *>(this));
+}
+
 /// getOperandNumber - Return which operand this is in the operand list of the
 /// using instruction.
 unsigned Operand::getOperandNumber() const {
diff --git a/lib/SILOptimizer/Transforms/CSE.cpp b/lib/SILOptimizer/Transforms/CSE.cpp
@@ -362,12 +362,21 @@ class HashVisitor : public SILInstructionVisitor<HashVisitor, llvm::hash_code> {
                               Operands.begin(),
                               Operands.end()));
   }
+
   hash_code visitMarkDependenceInst(MarkDependenceInst *X) {
     OperandValueArrayRef Operands(X->getAllOperands());
     return llvm::hash_combine(
         X->getKind(), X->getType(),
         llvm::hash_combine_range(Operands.begin(), Operands.end()));
   }
+
+  hash_code visitOpenExistentialRefInst(OpenExistentialRefInst *X) {
+    auto ArchetypeTy = cast<ArchetypeType>(X->getType().getSwiftRValueType());
+    auto ConformsTo = ArchetypeTy->getConformsTo();
+    return llvm::hash_combine(
+        X->getKind(), X->getOperand(),
+        llvm::hash_combine_range(ConformsTo.begin(), ConformsTo.end()));
+  }
 };
 } // end anonymous namespace
 
@@ -381,14 +390,33 @@ bool llvm::DenseMapInfo<SimpleValue>::isEqual(SimpleValue LHS,
   if (LHS.isSentinel() || RHS.isSentinel())
     return LHSI == RHSI;
 
+  if (isa<OpenExistentialRefInst>(LHSI) && isa<OpenExistentialRefInst>(RHSI)) {
+    if (LHSI->getNumOperands() != RHSI->getNumOperands())
+      return false;
+
+    // Check operands.
+    for (unsigned i = 0, e = LHSI->getNumOperands(); i != e; ++i)
+      if (LHSI->getOperand(i) !=  RHSI->getOperand(i))
+        return false;
+
+    // Consider the types of two open_existential_ref instructions to be equal,
+    // if the sets of protocols they conform to are equal.
+    auto LHSArchetypeTy =
+        cast<ArchetypeType>(LHSI->getType().getSwiftRValueType());
+    auto LHSConformsTo = LHSArchetypeTy->getConformsTo();
+    auto RHSArchetypeTy =
+        cast<ArchetypeType>(RHSI->getType().getSwiftRValueType());
+    auto RHSConformsTo = RHSArchetypeTy->getConformsTo();
+    return LHSConformsTo == RHSConformsTo;
+  }
   return LHSI->getKind() == RHSI->getKind() && LHSI->isIdenticalTo(RHSI);
 }
 
 //===----------------------------------------------------------------------===//
 //                               CSE Interface
 //===----------------------------------------------------------------------===//
 
-namespace {
+namespace swift {
 
 /// CSE - This pass does a simple depth-first walk over the dominator tree,
 /// eliminating trivially redundant instructions and using simplifyInstruction
@@ -476,6 +504,8 @@ class CSE {
   };
 
   bool processNode(DominanceInfoNode *Node);
+  bool processOpenExistentialRef(SILInstruction *Inst, ValueBase *V,
+                                 SILBasicBlock::iterator &I);
 };
 }  // end anonymous namespace
 
@@ -525,6 +555,95 @@ bool CSE::processFunction(SILFunction &Fm, DominanceInfo *DT) {
   return Changed;
 }
 
+namespace {
+  // A very simple cloner for cloning instructions inside
+  // the same function. The only interesting thing it does
+  // is remapping the archetypes when it is required.
+  class InstructionCloner : public SILCloner<InstructionCloner> {
+    friend class SILCloner<InstructionCloner>;
+    friend class SILVisitor<InstructionCloner>;
+    SILInstruction *Result = nullptr;
+  public:
+    InstructionCloner(SILFunction *F) : SILCloner(*F) {}
+
+    static SILInstruction *doIt(SILInstruction *I) {
+      InstructionCloner TC(I->getFunction());
+      return TC.clone(I);
+    }
+
+    SILInstruction *clone(SILInstruction *I) {
+      visit(I);
+      return Result;
+    }
+
+    void postProcess(SILInstruction *Orig, SILInstruction *Cloned) {
+      assert(Orig->getFunction() == &getBuilder().getFunction() &&
+             "cloning between functions is not supported");
+
+      Result = Cloned;
+      SILCloner<InstructionCloner>::postProcess(Orig, Cloned);
+    }
+    SILValue remapValue(SILValue Value) {
+      return Value;
+    }
+    SILBasicBlock *remapBasicBlock(SILBasicBlock *BB) { return BB; }
+  };
+}
+
+/// Handle CSE of open_existential_ref instructions.
+/// Returns true if uses of open_existential_ref can
+/// be replaced by a dominating instruction.
+/// \Inst is the open_existential_ref instruction
+/// \V is the dominating open_existential_ref instruction
+/// \I is the iterator referring to the current instruction.
+bool CSE::processOpenExistentialRef(SILInstruction *Inst, ValueBase *V,
+                                    SILBasicBlock::iterator &I) {
+  assert(isa<OpenExistentialRefInst>(Inst));
+  llvm::SmallSetVector<SILInstruction *, 16> Candidates;
+  // Collect all candidates that may contain opened archetypes
+  // that need to be replaced.
+  for (auto Use : Inst->getUses()) {
+    auto User = Use->getUser();
+    if (User->mayHaveOpenedArchetypeOperands()) {
+      if (canHandle(User)) {
+        auto It = AvailableValues->begin(User);
+        if (It != AvailableValues->end()) {
+          return false;
+        }
+      }
+      Candidates.insert(User);
+    }
+  }
+  // Now process candidates.
+  auto OldOpenedArchetype = getOpenedArchetypeOf(Inst);
+  auto NewOpenedArchetype = getOpenedArchetypeOf(dyn_cast<SILInstruction>(V));
+  // TODO: Move it to CSE instance to avoid recreating it every time?
+  SILOpenedArchetypesTracker OpenedArchetypesTracker(*Inst->getFunction());
+  // Register the new archetype to be used.
+  OpenedArchetypesTracker.registerOpenedArchetypes(dyn_cast<SILInstruction>(V));
+  // Use a cloner. It makes copying the instruction and remaping of
+  // opened archetypes trivial.
+  InstructionCloner Cloner(I->getFunction());
+  Cloner.registerOpenedExistentialRemapping(
+      OldOpenedArchetype->castTo<ArchetypeType>(), NewOpenedArchetype);
+  auto &Builder = Cloner.getBuilder();
+  Builder.setOpenedArchetypesTracker(&OpenedArchetypesTracker);
+
+  // Now clone each candidate and replace the opened archetype
+  // by a dominating one.
+  for (auto Candidate : Candidates) {
+    Builder.getOpenedArchetypes().addOpenedArchetypeOperands(
+        Candidate->getOpenedArchetypeOperands());
+    Builder.setInsertionPoint(Candidate);
+    auto NewI = Cloner.clone(Candidate);
+    Candidate->replaceAllUsesWith(NewI);
+    if (I == Candidate->getIterator())
+      I = NewI->getIterator();
+    eraseFromParentWithDebugInsts(Candidate, I);
+  }
+  return true;
+}
+
 bool CSE::processNode(DominanceInfoNode *Node) {
   SILBasicBlock *BB = Node->getBlock();
   bool Changed = false;
@@ -572,11 +691,17 @@ bool CSE::processNode(DominanceInfoNode *Node) {
     // instruction has an available value.  If so, use it.
     if (ValueBase *V = AvailableValues->lookup(Inst)) {
       DEBUG(llvm::dbgs() << "SILCSE CSE: " << *Inst << "  to: " << *V << '\n');
-      Inst->replaceAllUsesWith(V);
-      Inst->eraseFromParent();
-      Changed = true;
-      ++NumCSE;
-      continue;
+      // Instructions producing a new opened archetype need a special handling,
+      // because replacing these intructions may require a replacement
+      // of the opened archetype type operands in some of the uses.
+      if (!isa<OpenExistentialRefInst>(Inst) ||
+          processOpenExistentialRef(Inst, V, I)) {
+        Inst->replaceAllUsesWith(V);
+        Inst->eraseFromParent();
+        Changed = true;
+        ++NumCSE;
+        continue;
+      }
     }
 
     // Otherwise, just remember that this value is available.
@@ -687,6 +812,7 @@ bool CSE::canHandle(SILInstruction *Inst) {
     case ValueKind::ThinFunctionToPointerInst:
     case ValueKind::PointerToThinFunctionInst:
     case ValueKind::MarkDependenceInst:
+    case ValueKind::OpenExistentialRefInst:
       return true;
     default:
       return false;
diff --git a/lib/Serialization/SerializeSIL.cpp b/lib/Serialization/SerializeSIL.cpp
@@ -15,12 +15,14 @@
 #include "Serialization.h"
 #include "swift/Strings.h"
 #include "swift/AST/Module.h"
+#include "swift/SIL/CFG.h"
 #include "swift/SIL/SILArgument.h"
 #include "swift/SIL/SILModule.h"
 #include "swift/SIL/SILUndef.h"
 #include "swift/SILOptimizer/Utils/Generics.h"
 
 #include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
@@ -390,7 +392,10 @@ void SILSerializer::writeSILFunction(const SILFunction &F, bool DeclOnly) {
   // Assign a value ID to each SILInstruction that has value and to each basic
   // block argument.
   unsigned ValueID = 0;
-  for (const SILBasicBlock &BB : F) {
+  llvm::ReversePostOrderTraversal<SILFunction *> RPOT(
+      const_cast<SILFunction *>(&F));
+  for (auto Iter = RPOT.begin(), E = RPOT.end(); Iter != E; ++Iter) {
+    auto &BB = **Iter;
     BasicBlockMap.insert(std::make_pair(&BB, BasicID++));
 
     for (auto I = BB.bbarg_begin(), E = BB.bbarg_end(); I != E; ++I)
@@ -401,8 +406,17 @@ void SILSerializer::writeSILFunction(const SILFunction &F, bool DeclOnly) {
         ValueIDs[&SI] = ++ValueID;
   }
 
-  for (const SILBasicBlock &BB : F)
-    writeSILBasicBlock(BB);
+  // Write SIL basic blocks in the RPOT order
+  // to make sure that instructions defining open archetypes
+  // are serialized before instructions using those opened
+  // archetypes.
+  unsigned SerializedBBNum = 0;
+  for (auto Iter = RPOT.begin(), E = RPOT.end(); Iter != E; ++Iter) {
+    auto *BB = *Iter;
+    writeSILBasicBlock(*BB);
+    SerializedBBNum++;
+  }
+  assert(BasicID == SerializedBBNum && "Wrong number of BBs was serialized");
 }
 
 void SILSerializer::writeSILBasicBlock(const SILBasicBlock &BB) {
diff --git a/test/ClangModules/serialization-sil.swift b/test/ClangModules/serialization-sil.swift
@@ -10,36 +10,36 @@ public func testPartialApply(_ obj: Test) {
   // CHECK-LABEL: @_TF4Test16testPartialApplyFPSo4Test_T_ : $@convention(thin) (@owned Test) -> () {
   if let curried1 = obj.normalObject {
     // CHECK: dynamic_method_br [[CURRIED1_OBJ:%.+]] : $@opened([[CURRIED1_EXISTENTIAL:.+]]) Test, #Test.normalObject!1.foreign, [[CURRIED1_TRUE:[^,]+]], [[CURRIED1_FALSE:[^,]+]]
+    // CHECK: [[CURRIED1_FALSE]]:
     // CHECK: [[CURRIED1_TRUE]]([[CURRIED1_METHOD:%.+]] : $@convention(objc_method) (@opened([[CURRIED1_EXISTENTIAL]]) Test) -> @autoreleased AnyObject):
     // CHECK: [[CURRIED1_PARTIAL:%.+]] = partial_apply [[CURRIED1_METHOD]]([[CURRIED1_OBJ]]) : $@convention(objc_method) (@opened([[CURRIED1_EXISTENTIAL]]) Test) -> @autoreleased AnyObject
     // CHECK: [[CURRIED1_THUNK:%.+]] = function_ref @_TTRXFo__oPs9AnyObject__XFo_iT__iPS___ : $@convention(thin) (@in (), @owned @callee_owned () -> @owned AnyObject) -> @out AnyObject
     // CHECK: = partial_apply [[CURRIED1_THUNK]]([[CURRIED1_PARTIAL]]) : $@convention(thin) (@in (), @owned @callee_owned () -> @owned AnyObject) -> @out AnyObject
-    // CHECK: [[CURRIED1_FALSE]]:
     curried1()
   }
   if let curried2 = obj.innerPointer {
     // CHECK: dynamic_method_br [[CURRIED2_OBJ:%.+]] : $@opened([[CURRIED2_EXISTENTIAL:.+]]) Test, #Test.innerPointer!1.foreign, [[CURRIED2_TRUE:[^,]+]], [[CURRIED2_FALSE:[^,]+]]
+    // CHECK: [[CURRIED2_FALSE]]:
     // CHECK: [[CURRIED2_TRUE]]([[CURRIED2_METHOD:%.+]] : $@convention(objc_method) (@opened([[CURRIED2_EXISTENTIAL]]) Test) -> @unowned_inner_pointer UnsafeMutablePointer<()>):
     // CHECK: [[CURRIED2_PARTIAL:%.+]] = partial_apply [[CURRIED2_METHOD]]([[CURRIED2_OBJ]]) : $@convention(objc_method) (@opened([[CURRIED2_EXISTENTIAL]]) Test) -> @unowned_inner_pointer UnsafeMutablePointer<()>
     // CHECK: [[CURRIED2_THUNK:%.+]] = function_ref @_TTRXFo__dGSpT___XFo_iT__iGSpT___ : $@convention(thin) (@in (), @owned @callee_owned () -> UnsafeMutablePointer<()>) -> @out UnsafeMutablePointer<()>
     // CHECK: = partial_apply [[CURRIED2_THUNK]]([[CURRIED2_PARTIAL]]) : $@convention(thin) (@in (), @owned @callee_owned () -> UnsafeMutablePointer<()>) -> @out UnsafeMutablePointer<()>
-    // CHECK: [[CURRIED2_FALSE]]:
     curried2()
   }
   if let prop1 = obj.normalObjectProp {
     // CHECK: dynamic_method_br [[PROP1_OBJ:%.+]] : $@opened([[PROP1_EXISTENTIAL:.+]]) Test, #Test.normalObjectProp!getter.1.foreign, [[PROP1_TRUE:[^,]+]], [[PROP1_FALSE:[^,]+]]
+    // CHECK: [[PROP1_FALSE]]:
     // CHECK: [[PROP1_TRUE]]([[PROP1_METHOD:%.+]] : $@convention(objc_method) (@opened([[PROP1_EXISTENTIAL]]) Test) -> @autoreleased AnyObject):
     // CHECK: [[PROP1_PARTIAL:%.+]] = partial_apply [[PROP1_METHOD]]([[PROP1_OBJ]]) : $@convention(objc_method) (@opened([[PROP1_EXISTENTIAL]]) Test) -> @autoreleased AnyObject
     // CHECK: = apply [[PROP1_PARTIAL]]() : $@callee_owned () -> @owned AnyObject
-    // CHECK: [[PROP1_FALSE]]:
     _ = prop1
   }
   if let prop2 = obj.innerPointerProp {
     // CHECK: dynamic_method_br [[PROP2_OBJ:%.+]] : $@opened([[PROP2_EXISTENTIAL:.+]]) Test, #Test.innerPointerProp!getter.1.foreign, [[PROP2_TRUE:[^,]+]], [[PROP2_FALSE:[^,]+]]
+    // CHECK: [[PROP2_FALSE]]:
     // CHECK: [[PROP2_TRUE]]([[PROP2_METHOD:%.+]] : $@convention(objc_method) (@opened([[PROP2_EXISTENTIAL]]) Test) -> @unowned_inner_pointer UnsafeMutablePointer<()>):
     // CHECK: [[PROP2_PARTIAL:%.+]] = partial_apply [[PROP2_METHOD]]([[PROP2_OBJ]]) : $@convention(objc_method) (@opened([[PROP2_EXISTENTIAL]]) Test) -> @unowned_inner_pointer UnsafeMutablePointer<()>
     // CHECK: = apply [[PROP2_PARTIAL]]() : $@callee_owned () -> UnsafeMutablePointer<()>
-    // CHECK: [[PROP2_FALSE]]:
     _ = prop2
   }
 } // CHECK: {{^}$}}
diff --git a/test/SILOptimizer/cse.sil b/test/SILOptimizer/cse.sil
@@ -1319,3 +1319,51 @@ bb0(%0 : $*Builtin.Int64, %1 : $Builtin.NativeObject):
   %6 = tuple(%4 : $Builtin.Int64, %5 : $Builtin.Int64)
   return %6 : $(Builtin.Int64, Builtin.Int64)
 }
+
+protocol Proto : class {
+  func doThis()
+  func doThat()
+}
+
+// Check that all open_existential_ref instructions are CSEd 
+// CHECK-LABEL: sil @cse_open_existential : $@convention(thin) (@guaranteed Proto, Bool) -> ()
+// CHECK: bb0
+// CHECK: %[[OPENED_EXISTENTIAL:[0-9]+]] = open_existential_ref %{{[0-9]+}} : $Proto to $@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto
+// CHECK: %[[WM1:[0-9]+]] = witness_method $@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto, #Proto.doThis!1
+// CHECK: apply %[[WM1]]{{.*}}(%[[OPENED_EXISTENTIAL]])
+// CHECK: cond_br
+// CHECK: bb1:
+// CHECK-NEXT: %[[WM2:[0-9]+]] = witness_method $@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto, #Proto.doThat!1
+// CHECK-NEXT: apply %[[WM2]]{{.*}}(%[[OPENED_EXISTENTIAL]])
+// CHECK-NEXT: br
+// CHECK: bb2:
+// CHECK-NEXT: apply %[[WM1]]{{.*}}(%[[OPENED_EXISTENTIAL]])
+// CHECK-NEXT: br
+// CHECK: bb3:
+// CHECK-NEXT: tuple
+// CHECK-NEXT: return
+sil @cse_open_existential : $@convention(thin) (@guaranteed Proto, Bool) -> () {
+bb0(%0 : $Proto, %1 : $Bool):
+  %4 = open_existential_ref %0 : $Proto to $@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto
+  %5 = witness_method $@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto, #Proto.doThis!1, %4 : $@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto : $@convention(witness_method) <τ_0_0 where τ_0_0 : Proto> (@guaranteed τ_0_0) -> ()
+  %6 = apply %5<@opened("1B68354A-4796-11E6-B7DF-B8E856428C60") Proto>(%4) : $@convention(witness_method) <τ_0_0 where τ_0_0 : Proto> (@guaranteed τ_0_0) -> ()
+  %7 = struct_extract %1 : $Bool, #Bool._value
+  cond_br %7, bb1, bb2
+
+bb1:
+  %9 = open_existential_ref %0 : $Proto to $@opened("1B685052-4796-11E6-B7DF-B8E856428C60") Proto
+  %10 = witness_method $@opened("1B685052-4796-11E6-B7DF-B8E856428C60") Proto, #Proto.doThat!1, %9 : $@opened("1B685052-4796-11E6-B7DF-B8E856428C60") Proto : $@convention(witness_method) <τ_0_0 where τ_0_0 : Proto> (@guaranteed τ_0_0) -> ()
+  %11 = apply %10<@opened("1B685052-4796-11E6-B7DF-B8E856428C60") Proto>(%9) : $@convention(witness_method) <τ_0_0 where τ_0_0 : Proto> (@guaranteed τ_0_0) -> ()
+  br bb3
+
+bb2:                                              // Preds: bb0
+  %13 = open_existential_ref %0 : $Proto to $@opened("1B6851A6-4796-11E6-B7DF-B8E856428C60") Proto
+  %14 = witness_method $@opened("1B6851A6-4796-11E6-B7DF-B8E856428C60") Proto, #Proto.doThis!1, %13 : $@opened("1B6851A6-4796-11E6-B7DF-B8E856428C60") Proto : $@convention(witness_method) <τ_0_0 where τ_0_0 : Proto> (@guaranteed τ_0_0) -> ()
+  %15 = apply %14<@opened("1B6851A6-4796-11E6-B7DF-B8E856428C60") Proto>(%13) : $@convention(witness_method) <τ_0_0 where τ_0_0 : Proto> (@guaranteed τ_0_0) -> ()
+  br bb3
+
+bb3:
+  %17 = tuple ()
+  return %17 : $()
+}
+
diff --git a/test/Serialization/Inputs/def_basic.sil b/test/Serialization/Inputs/def_basic.sil
diff --git a/test/Serialization/transparent.swift b/test/Serialization/transparent.swift
