[semantic-arc-opts] Extract out the conversion of owned -> guaranteed forwarding insts into a general utility.

I am going to use this to handle converting from guaranteed -> owned in a
different context.

Author: gottesmm

lib/SILOptimizer/Transforms/SemanticARCOpts.cpp

@@ -505,63 +505,69 @@ void OwnershipLiveRange::insertEndBorrowsAtDestroys(
   }
 }
 
-void OwnershipLiveRange::convertOwnedGeneralForwardingUsesToGuaranteed() && {
-  while (!ownershipForwardingUses.empty()) {
-    auto *i = ownershipForwardingUses.back()->getUser();
-    ownershipForwardingUses = ownershipForwardingUses.drop_back();
-
-    // If this is a term inst, just convert all of its incoming values that are
-    // owned to be guaranteed.
-    if (auto *ti = dyn_cast<TermInst>(i)) {
-      for (auto &succ : ti->getSuccessors()) {
-        auto *succBlock = succ.getBB();
+static void convertInstructionOwnership(SILInstruction *i,
+                                        ValueOwnershipKind oldOwnership,
+                                        ValueOwnershipKind newOwnership) {
+  // If this is a term inst, just convert all of its incoming values that are
+  // owned to be guaranteed.
+  if (auto *ti = dyn_cast<TermInst>(i)) {
+    for (auto &succ : ti->getSuccessors()) {
+      auto *succBlock = succ.getBB();
 
-        // If we do not have any arguments, then continue.
-        if (succBlock->args_empty())
-          continue;
+      // If we do not have any arguments, then continue.
+      if (succBlock->args_empty())
+        continue;
 
-        for (auto *succArg : succBlock->getSILPhiArguments()) {
-          // If we have an any value, just continue.
-          if (succArg->getOwnershipKind() == ValueOwnershipKind::Owned) {
-            succArg->setOwnershipKind(ValueOwnershipKind::Guaranteed);
-          }
+      for (auto *succArg : succBlock->getSILPhiArguments()) {
+        // If we have an any value, just continue.
+        if (succArg->getOwnershipKind() == oldOwnership) {
+          succArg->setOwnershipKind(newOwnership);
         }
       }
-      continue;
     }
+    return;
+  }
 
-    assert(i->hasResults());
-    for (SILValue result : i->getResults()) {
-      if (auto *svi = dyn_cast<OwnershipForwardingSingleValueInst>(result)) {
-        if (svi->getOwnershipKind() == ValueOwnershipKind::Owned) {
-          svi->setOwnershipKind(ValueOwnershipKind::Guaranteed);
-        }
-        continue;
+  assert(i->hasResults());
+  for (SILValue result : i->getResults()) {
+    if (auto *svi = dyn_cast<OwnershipForwardingSingleValueInst>(result)) {
+      if (svi->getOwnershipKind() == oldOwnership) {
+        svi->setOwnershipKind(newOwnership);
       }
+      continue;
+    }
 
-      if (auto *ofci = dyn_cast<OwnershipForwardingConversionInst>(result)) {
-        if (ofci->getOwnershipKind() == ValueOwnershipKind::Owned) {
-          ofci->setOwnershipKind(ValueOwnershipKind::Guaranteed);
-        }
-        continue;
+    if (auto *ofci = dyn_cast<OwnershipForwardingConversionInst>(result)) {
+      if (ofci->getOwnershipKind() == oldOwnership) {
+        ofci->setOwnershipKind(newOwnership);
       }
+      continue;
+    }
 
-      if (auto *sei = dyn_cast<OwnershipForwardingSelectEnumInstBase>(result)) {
-        if (sei->getOwnershipKind() == ValueOwnershipKind::Owned) {
-          sei->setOwnershipKind(ValueOwnershipKind::Guaranteed);
-        }
-        continue;
+    if (auto *sei = dyn_cast<OwnershipForwardingSelectEnumInstBase>(result)) {
+      if (sei->getOwnershipKind() == oldOwnership) {
+        sei->setOwnershipKind(newOwnership);
       }
+      continue;
+    }
 
-      if (auto *mvir = dyn_cast<MultipleValueInstructionResult>(result)) {
-        if (mvir->getOwnershipKind() == ValueOwnershipKind::Owned) {
-          mvir->setOwnershipKind(ValueOwnershipKind::Guaranteed);
-        }
-        continue;
+    if (auto *mvir = dyn_cast<MultipleValueInstructionResult>(result)) {
+      if (mvir->getOwnershipKind() == oldOwnership) {
+        mvir->setOwnershipKind(newOwnership);
       }
-
-      llvm_unreachable("unhandled forwarding instruction?!");
+      continue;
     }
+
+    llvm_unreachable("unhandled forwarding instruction?!");
+  }
+}
+
+void OwnershipLiveRange::convertOwnedGeneralForwardingUsesToGuaranteed() && {
+  while (!ownershipForwardingUses.empty()) {
+    auto *i = ownershipForwardingUses.back()->getUser();
+    ownershipForwardingUses = ownershipForwardingUses.drop_back();
+    convertInstructionOwnership(i, ValueOwnershipKind::Owned,
+                                ValueOwnershipKind::Guaranteed);
   }
 }