[SILOptimizer] Open existential actors for hop_to_executor as part of the

LowerHopToActor pass instead of during SILGen.

Author: hborla

lib/SILGen/SILGenProlog.cpp

@@ -1507,15 +1507,6 @@ SILValue SILGenFunction::emitLoadActorExecutor(SILLocation loc,
   else
     actorV = actor.borrow(*this, loc).getValue();
 
-  // Open an existential actor type.
-  CanType actorType = actor.getType().getASTType();
-  if (actorType->isExistentialType()) {
-    actorType = OpenedArchetypeType::get(
-        actorType, F.getGenericSignature())->getCanonicalType();
-    SILType loweredActorType = getLoweredType(actorType);
-    actorV = B.createOpenExistentialRef(loc, actorV, loweredActorType);
-  }
-
   // For now, we just want to emit a hop_to_executor directly to the
   // actor; LowerHopToActor will add the emission logic necessary later.
   return actorV;

lib/SILOptimizer/Mandatory/LowerHopToActor.cpp

@@ -204,6 +204,16 @@ SILValue LowerHopToActor::emitGetExecutor(SILBuilderWithScope &B,
     assert(req && "Concurrency library broken");
     SILDeclRef fn(req, SILDeclRef::Kind::Func);
 
+    // FIXME: Handle optional
+
+    // Open an existential actor type.
+    if (actorType->isExistentialType()) {
+      actorType = OpenedArchetypeType::get(
+          actorType, F->getGenericSignature())->getCanonicalType();
+      SILType loweredActorType = F->getLoweredType(actorType);
+      actor = B.createOpenExistentialRef(loc, actor, loweredActorType);
+    }
+
     auto actorConf = module->lookupConformance(actorType, actorProtocol);
     assert(actorConf &&
            "hop_to_executor with actor that doesn't conform to Actor or DistributedActor");

test/SILGen/isolated_parameters.swift

@@ -31,7 +31,6 @@ public func testClosureWithIsolatedParam() {
 public func testIsolatedExistential(_ a: isolated Actor) async {
   // CHECK: [[ACTOR_COPY:%.*]] = copy_value [[ACTOR]] : $any Actor
   // CHECK: [[ACTOR_BORROW:%.*]] = begin_borrow [[ACTOR_COPY]] : $any Actor
-  // CHECK: [[ACTOR_OPENED:%.*]] = open_existential_ref [[ACTOR_BORROW]] : $any Actor to $@opened("{{.*}}", any Actor) Self
-  // CHECK: hop_to_executor [[ACTOR_OPENED]] : $@opened("{{.*}}", any Actor) Self
+  // CHECK: hop_to_executor [[ACTOR_BORROW]] : $any Actor
   // CHECK: return
 }