Re-apply thunk generic signature optimization

lib/AST/ASTContext.cpp

@@ -2551,6 +2551,9 @@ void ASTContext::dumpArchetypeContext(ArchetypeType *archetype,
 void ASTContext::dumpArchetypeContext(ArchetypeType *archetype,
                                       llvm::raw_ostream &os,
                                       unsigned indent) const {
+  if (archetype->isOpenedExistential())
+    return;
+
   archetype = archetype->getPrimary();
   if (!archetype)
     return;

lib/SIL/SILInstructions.cpp

@@ -68,6 +68,7 @@ static void buildTypeDependentOperands(
   for (auto archetype : OpenedArchetypes) {
     auto Def = OpenedArchetypesState.getOpenedArchetypeDef(
         F.getModule().Types.getLoweredType(archetype).getSwiftRValueType());
+    assert(Def);
     assert(getOpenedArchetypeOf(Def->getType().getSwiftRValueType()) &&
            "Opened archetype operands should be of an opened existential type");
     TypeDependentOperands.push_back(Def);

lib/SILGen/SILGenBridging.cpp

@@ -350,22 +350,30 @@ ManagedValue SILGenFunction::emitFuncToBlock(SILLocation loc,
             blockInterfaceTy->getParameters().end(),
             std::back_inserter(params));
 
-  auto genericSig = F.getLoweredFunctionType()->getGenericSignature();
-  auto genericEnv = F.getGenericEnvironment();
   auto extInfo =
       SILFunctionType::ExtInfo()
         .withRepresentation(SILFunctionType::Representation::CFunctionPointer);
 
-  // The block invoke function must be pseudogeneric. This should be OK for now
-  // since a bridgeable function's parameters and returns should all be
-  // trivially representable in ObjC so not need to exercise the type metadata.
-  //
-  // Ultimately we may need to capture generic parameters in block storage, but
-  // that will require a redesign of the interface to support dependent-layout
-  // context. Currently we don't capture anything directly into a block but a
-  // Swift closure, but that's totally dumb.
-  if (genericSig)
-    extInfo = extInfo.withIsPseudogeneric();
+  CanGenericSignature genericSig;
+  GenericEnvironment *genericEnv = nullptr;
+  ArrayRef<Substitution> subs;
+  if (fnTy->hasArchetype() || blockTy->hasArchetype()) {
+    genericSig = F.getLoweredFunctionType()->getGenericSignature();
+    genericEnv = F.getGenericEnvironment();
+
+    subs = F.getForwardingSubstitutions();
+
+    // The block invoke function must be pseudogeneric. This should be OK for now
+    // since a bridgeable function's parameters and returns should all be
+    // trivially representable in ObjC so not need to exercise the type metadata.
+    //
+    // Ultimately we may need to capture generic parameters in block storage, but
+    // that will require a redesign of the interface to support dependent-layout
+    // context. Currently we don't capture anything directly into a block but a
+    // Swift closure, but that's totally dumb.
+    if (genericSig)
+      extInfo = extInfo.withIsPseudogeneric();
+  }
 
   auto invokeTy =
     SILFunctionType::get(genericSig,
@@ -404,7 +412,7 @@ ManagedValue SILGenFunction::emitFuncToBlock(SILLocation loc,
 
   auto stackBlock = B.createInitBlockStorageHeader(loc, storage, invokeFn,
                                       SILType::getPrimitiveObjectType(blockTy),
-                                      getForwardingSubstitutions());
+                                      subs);
 
   // Copy the block so we have an independent heap object we can hand off.
   auto heapBlock = B.createCopyBlock(loc, stackBlock);
@@ -622,10 +630,16 @@ SILGenFunction::emitBlockToFunc(SILLocation loc,
   CanSILFunctionType substFnTy;
   SmallVector<Substitution, 4> subs;
 
+  auto genericEnv = F.getGenericEnvironment();
+
   // Declare the thunk.
   auto blockTy = block.getType().castTo<SILFunctionType>();
+
   auto thunkTy = buildThunkType(block, funcTy, substFnTy, subs);
-  auto thunk = SGM.getOrCreateReabstractionThunk(F.getGenericEnvironment(),
+  if (!thunkTy->isPolymorphic())
+    genericEnv = nullptr;
+
+  auto thunk = SGM.getOrCreateReabstractionThunk(genericEnv,
                                                  thunkTy,
                                                  blockTy,
                                                  funcTy,
@@ -634,7 +648,7 @@ SILGenFunction::emitBlockToFunc(SILLocation loc,
   // Build it if necessary.
   if (thunk->empty()) {
     SILGenFunction thunkSGF(SGM, *thunk);
-    thunk->setGenericEnvironment(F.getGenericEnvironment());
+    thunk->setGenericEnvironment(genericEnv);
     auto loc = RegularLocation::getAutoGeneratedLocation();
     buildBlockToFuncThunkBody(thunkSGF, loc, blockTy, funcTy);
   }

lib/SILGen/SILGenPoly.cpp

@@ -2314,11 +2314,24 @@ CanSILFunctionType SILGenFunction::buildThunkType(
   // on the result type.
   assert(expectedType->getExtInfo().hasContext());
 
-  // Just use the generic signature from the context.
-  // This isn't necessarily optimal.
-  auto genericSig = F.getLoweredFunctionType()->getGenericSignature();
-  auto subsArray = F.getForwardingSubstitutions();
-  subs.append(subsArray.begin(), subsArray.end());
+  auto extInfo = expectedType->getExtInfo()
+    .withRepresentation(SILFunctionType::Representation::Thin);
+
+  // Use the generic signature from the context if the thunk involves
+  // generic parameters.
+  CanGenericSignature genericSig;
+  GenericEnvironment *genericEnv = nullptr;
+  if (expectedType->hasArchetype() || sourceType->hasArchetype()) {
+    genericSig = F.getLoweredFunctionType()->getGenericSignature();
+    genericEnv = F.getGenericEnvironment();
+    auto subsArray = F.getForwardingSubstitutions();
+    subs.append(subsArray.begin(), subsArray.end());
+
+    // If our parent function was pseudogeneric, this thunk must also be
+    // pseudogeneric, since we have no way to pass generic parameters.
+    if (F.getLoweredFunctionType()->isPseudogeneric())
+      extInfo = extInfo.withIsPseudogeneric();
+  }
 
   // Add the function type as the parameter.
   SmallVector<SILParameterInfo, 4> params;
@@ -2328,14 +2341,6 @@ CanSILFunctionType SILGenFunction::buildThunkType(
                     sourceType->getExtInfo().hasContext()
                       ? DefaultThickCalleeConvention
                       : ParameterConvention::Direct_Unowned});
-
-  auto extInfo = expectedType->getExtInfo()
-    .withRepresentation(SILFunctionType::Representation::Thin);
-
-  // If our parent function was pseudogeneric, this thunk must also be
-  // pseudogeneric, since we have no way to pass generic parameters.
-  if (F.getLoweredFunctionType()->isPseudogeneric())
-    extInfo = extInfo.withIsPseudogeneric();
 
   // Map the parameter and expected types out of context to get the interface
   // type of the thunk.
@@ -2406,10 +2411,15 @@ static ManagedValue createThunk(SILGenFunction &gen,
   // Declare the thunk.
   SmallVector<Substitution, 4> substitutions;
   CanSILFunctionType substFnType;
+
   auto thunkType = gen.buildThunkType(fn, expectedType,
                                   substFnType, substitutions);
+  auto genericEnv = gen.F.getGenericEnvironment();
+  if (!thunkType->isPolymorphic())
+    genericEnv = nullptr;
+
   auto thunk = gen.SGM.getOrCreateReabstractionThunk(
-                                       gen.F.getGenericEnvironment(),
+                                       genericEnv,
                                        thunkType,
                                        fn.getType().castTo<SILFunctionType>(),
                                        expectedType,
@@ -2418,7 +2428,7 @@ static ManagedValue createThunk(SILGenFunction &gen,
   // Build it if necessary.
   if (thunk->empty()) {
     // Borrow the context archetypes from the enclosing function.
-    thunk->setGenericEnvironment(gen.F.getGenericEnvironment());
+    thunk->setGenericEnvironment(genericEnv);
     SILGenFunction thunkSGF(gen.SGM, *thunk);
     auto loc = RegularLocation::getAutoGeneratedLocation();
     buildThunkBody(thunkSGF, loc,

lib/SILOptimizer/Analysis/EscapeAnalysis.cpp

@@ -561,8 +561,10 @@ bool EscapeAnalysis::ConnectionGraph::isReachable(CGNode *From, CGNode *To) {
   From->isInWorkList = true;
   for (unsigned Idx = 0; Idx < WorkList.size(); ++Idx) {
     CGNode *Reachable = WorkList[Idx];
-    if (Reachable == To)
+    if (Reachable == To) {
+      clearWorkListFlags(WorkList);
       return true;
+    }
     for (Predecessor Pred : Reachable->Preds) {
       CGNode *PredNode = Pred.getPointer();
       if (!PredNode->isInWorkList) {

lib/SILOptimizer/SILCombiner/SILCombinerApplyVisitors.cpp

@@ -91,22 +91,6 @@ SILInstruction *SILCombiner::visitPartialApplyInst(PartialApplyInst *PAI) {
   return nullptr;
 }
 
-static bool canCombinePartialApply(const PartialApplyInst *PAI) {
-  // Only process partial apply if the callee is a known function.
-  auto *FRI = dyn_cast<FunctionRefInst>(PAI->getCallee());
-  if (!FRI)
-    return false;
-
-  // Make sure that the substitution list of the PAI does not contain any
-  // archetypes.
-  ArrayRef<Substitution> Subs = PAI->getSubstitutions();
-  for (Substitution S : Subs)
-    if (S.getReplacement()->getCanonicalType()->hasArchetype())
-      return false;
-
-  return true;
-}
-
 // Helper class performing the apply{partial_apply(x,y)}(z) -> apply(z,x,y)
 // peephole.
 class PartialApplyCombiner {
@@ -132,9 +116,6 @@ class PartialApplyCombiner {
 
   SILBuilder &Builder;
 
-  // Function referenced by partial_apply.
-  FunctionRefInst *FRI;
-
   SILCombiner *SilCombiner;
 
   bool processSingleApply(FullApplySite AI);
@@ -146,7 +127,7 @@ class PartialApplyCombiner {
   PartialApplyCombiner(PartialApplyInst *PAI, SILBuilder &Builder,
                        SILCombiner *SilCombiner)
       : isFirstTime(true), PAI(PAI), Builder(Builder),
-        FRI(nullptr), SilCombiner(SilCombiner) {}
+        SilCombiner(SilCombiner) {}
   SILInstruction *combine();
 };
 
@@ -280,10 +261,8 @@ bool PartialApplyCombiner::processSingleApply(FullApplySite AI) {
   for (auto Op : PAI->getArguments()) {
     auto Arg = Op;
     // If there is new temporary for this argument, use it instead.
-    if (isa<AllocStackInst>(Arg)) {
-      if (ArgToTmp.count(Arg)) {
-        Op = ArgToTmp.lookup(Arg);
-      }
+    if (ArgToTmp.count(Arg)) {
+      Op = ArgToTmp.lookup(Arg);
     }
     Args.push_back(Op);
   }
@@ -314,24 +293,23 @@ bool PartialApplyCombiner::processSingleApply(FullApplySite AI) {
     }
   }
 
-  auto *F = FRI->getReferencedFunction();
-  SILType FnType = F->getLoweredType();
-  SILType ResultTy = F->getLoweredFunctionType()->getSILResult();
+  auto Callee = PAI->getCallee();
+  auto FnType = PAI->getSubstCalleeSILType();
+  SILType ResultTy = PAI->getSubstCalleeType()->getSILResult();
   ArrayRef<Substitution> Subs = PAI->getSubstitutions();
-  if (!Subs.empty()) {
-    FnType = FnType.substGenericArgs(PAI->getModule(), Subs);
-    ResultTy = FnType.getAs<SILFunctionType>()->getSILResult();
-  }
+
+  // The partial_apply might be substituting in an open existential type.
+  Builder.addOpenedArchetypeOperands(PAI);
 
   FullApplySite NAI;
   if (auto *TAI = dyn_cast<TryApplyInst>(AI))
     NAI =
-      Builder.createTryApply(AI.getLoc(), FRI, FnType, Subs, Args,
+      Builder.createTryApply(AI.getLoc(), Callee, FnType, Subs, Args,
                               TAI->getNormalBB(), TAI->getErrorBB());
   else
     NAI =
-      Builder.createApply(AI.getLoc(), FRI, FnType, ResultTy, Subs, Args,
-                           cast<ApplyInst>(AI)->isNonThrowing());
+      Builder.createApply(AI.getLoc(), Callee, FnType, ResultTy, Subs, Args,
+                          cast<ApplyInst>(AI)->isNonThrowing());
 
   // We also need to release the partial_apply instruction itself because it
   // is consumed by the apply_instruction.
@@ -365,11 +343,11 @@ bool PartialApplyCombiner::processSingleApply(FullApplySite AI) {
 /// by iterating over all uses of the partial_apply and searching
 /// for the pattern to transform.
 SILInstruction *PartialApplyCombiner::combine() {
-  if (!canCombinePartialApply(PAI))
-    return nullptr;
-
-  // Only process partial apply if the callee is a known function.
-  FRI = dyn_cast<FunctionRefInst>(PAI->getCallee());
+  // We need to model @unowned_inner_pointer better before we can do the
+  // peephole here.
+  for (auto R : PAI->getSubstCalleeType()->getAllResults())
+    if (R.getConvention() == ResultConvention::UnownedInnerPointer)
+      return nullptr;
 
   // Iterate over all uses of the partial_apply
   // and look for applies that use it as a callee.

test/SILGen/generic_closures.swift

@@ -109,8 +109,8 @@ class NestedGeneric<U> {
   }
 
   // CHECK-LABEL: sil hidden @_TFC16generic_closures13NestedGeneric20nested_reabstraction{{.*}}
-  //   CHECK:       [[REABSTRACT:%.*]] = function_ref @_TTRG__rXFo___XFo_iT__iT__
-  //   CHECK:       partial_apply [[REABSTRACT]]<U, T>
+  //   CHECK:       [[REABSTRACT:%.*]] = function_ref @_TTRXFo___XFo_iT__iT__
+  //   CHECK:       partial_apply [[REABSTRACT]]
   func nested_reabstraction<T>(_ x: T) -> Optionable<() -> ()> {
     return .some({})
   }
@@ -213,8 +213,8 @@ func outer_generic<T>(t: T, i: Int) {
   let _: () -> () = inner_generic_nocapture
   // CHECK: [[FN:%.*]] = function_ref @_TFF16generic_closures13outer_genericurFT1tx1iSi_T_L_23inner_generic_nocaptureu__rFT1uqd___qd__ : $@convention(thin) <τ_0_0><τ_1_0> (@in τ_1_0) -> @out τ_1_0
   // CHECK: [[CLOSURE:%.*]] = partial_apply [[FN]]<T, ()>() : $@convention(thin) <τ_0_0><τ_1_0> (@in τ_1_0) -> @out τ_1_0
-  // CHECK: [[THUNK:%.*]] = function_ref @_TTRGrXFo_iT__iT__XFo___
-  // CHECK: [[THUNK_CLOSURE:%.*]] = partial_apply [[THUNK]]<T>([[CLOSURE]])
+  // CHECK: [[THUNK:%.*]] = function_ref @_TTRXFo_iT__iT__XFo___
+  // CHECK: [[THUNK_CLOSURE:%.*]] = partial_apply [[THUNK]]([[CLOSURE]])
   // CHECK: strong_release [[THUNK_CLOSURE]]
 
   // CHECK: [[FN:%.*]] = function_ref @_TFF16generic_closures13outer_genericurFT1tx1iSi_T_L_23inner_generic_nocaptureu__rFT1uqd___qd__ : $@convention(thin) <τ_0_0><τ_1_0> (@in τ_1_0) -> @out τ_1_0
@@ -223,8 +223,8 @@ func outer_generic<T>(t: T, i: Int) {
 
   // CHECK: [[FN:%.*]] = function_ref @_TFF16generic_closures13outer_genericurFT1tx1iSi_T_L_14inner_generic1u__rfT1uqd___Si : $@convention(thin) <τ_0_0><τ_1_0> (@in τ_1_0, Int) -> Int
   // CHECK: [[CLOSURE:%.*]] = partial_apply [[FN]]<T, ()>(%1) : $@convention(thin) <τ_0_0><τ_1_0> (@in τ_1_0, Int) -> Int
-  // CHECK: [[THUNK:%.*]] = function_ref @_TTRGrXFo_iT__dSi_XFo__dSi_
-  // CHECK: [[THUNK_CLOSURE:%.*]] = partial_apply [[THUNK]]<T>([[CLOSURE]])
+  // CHECK: [[THUNK:%.*]] = function_ref @_TTRXFo_iT__dSi_XFo__dSi_
+  // CHECK: [[THUNK_CLOSURE:%.*]] = partial_apply [[THUNK]]([[CLOSURE]])
   // CHECK: strong_release [[THUNK_CLOSURE]]
   let _: () -> Int = inner_generic1
 

test/SILGen/generic_objc_block_bridge.swift

@@ -14,4 +14,4 @@ class Tubb<GenericParamName>: Butt {
   }
 }
 
-// CHECK-LABEL: sil shared [transparent] [reabstraction_thunk] @_TTRGrXFdCb_dSi_dSi_XFo_dSi_dSi_ : $@convention(thin) <GenericParamName> (Int, @owned @convention(block) (Int) -> Int) -> Int {
+// CHECK-LABEL: sil shared [transparent] [reabstraction_thunk] @_TTRXFdCb_dSi_dSi_XFo_dSi_dSi_ : $@convention(thin) (Int, @owned @convention(block) (Int) -> Int) -> Int {

test/SILGen/objc_blocks_bridging.swift

@@ -150,6 +150,6 @@ struct GenericStruct<T> {
   }
 }
 
-// CHECK-LABEL: sil shared [transparent] [reabstraction_thunk] @_TTRgrXFo_oXFo_____XFdCb_dXFdCb_____ : $@convention(c) @pseudogeneric <T> (@inout_aliasable @block_storage @callee_owned (@owned @callee_owned () -> ()) -> (), @convention(block) () -> ()) -> ()
-// CHECK-LABEL: sil shared [transparent] [reabstraction_thunk] @_TTRgrXFdCb___XFo___ : $@convention(thin) @pseudogeneric <T> (@owned @convention(block) () -> ()) -> ()
+// CHECK-LABEL: sil shared [transparent] [reabstraction_thunk] @_TTRXFo_oXFo_____XFdCb_dXFdCb_____ : $@convention(c) (@inout_aliasable @block_storage @callee_owned (@owned @callee_owned () -> ()) -> (), @convention(block) () -> ()) -> ()
+// CHECK-LABEL: sil shared [transparent] [reabstraction_thunk] @_TTRXFdCb___XFo___ : $@convention(thin) (@owned @convention(block) () -> ()) -> ()
 

test/SILGen/property_abstraction.swift

@@ -128,5 +128,5 @@ func setBuilder<F: Factory where F.Product == MyClass>(_ factory: inout F) {
 // CHECK:   [[F1:%.*]] = thin_to_thick_function [[F0]]
 // CHECK:   [[SETTER:%.*]] = witness_method $F, #Factory.builder!setter.1
 // CHECK:   [[REABSTRACTOR:%.*]] = function_ref @_TTR
-// CHECK:   [[F2:%.*]] = partial_apply [[REABSTRACTOR]]<F>([[F1]])
+// CHECK:   [[F2:%.*]] = partial_apply [[REABSTRACTOR]]([[F1]])
 // CHECK:   apply [[SETTER]]<F, MyClass>([[F2]], [[PB]])