Delete OperandOwnership::GuaranteedForwardingPhi

Use OperandOwnership::GuaranteedForwarding instead.

Author: meg-gupta

include/swift/SIL/SILValue.h

@@ -833,8 +833,6 @@ struct OperandOwnership {
     /// borrow scope.
     /// (tuple_extract, struct_extract, cast, switch)
     GuaranteedForwarding,
-    /// A GuaranteedForwarding value passed as a phi operand.
-    GuaranteedForwardingPhi,
     /// End Borrow. End the borrow scope opened directly by the operand.
     /// The operand must be a begin_borrow, begin_apply, or function argument.
     /// (end_borrow, end_apply)
@@ -927,7 +925,6 @@ inline OwnershipConstraint OperandOwnership::getOwnershipConstraint() {
     return {OwnershipKind::Owned, UseLifetimeConstraint::LifetimeEnding};
   case OperandOwnership::InteriorPointer:
   case OperandOwnership::GuaranteedForwarding:
-  case OperandOwnership::GuaranteedForwardingPhi:
     return {OwnershipKind::Guaranteed,
             UseLifetimeConstraint::NonLifetimeEnding};
   case OperandOwnership::EndBorrow:
@@ -956,7 +953,6 @@ inline bool canAcceptUnownedValue(OperandOwnership operandOwnership) {
   case OperandOwnership::ForwardingConsume:
   case OperandOwnership::InteriorPointer:
   case OperandOwnership::GuaranteedForwarding:
-  case OperandOwnership::GuaranteedForwardingPhi:
   case OperandOwnership::EndBorrow:
   case OperandOwnership::Reborrow:
     return false;

lib/SIL/IR/OperandOwnership.cpp

@@ -431,7 +431,7 @@ OperandOwnership OperandOwnershipClassifier::visitBranchInst(BranchInst *bi) {
 
   if (destBlockArgOwnershipKind == OwnershipKind::Guaranteed) {
     return isGuaranteedForwarding(getValue())
-               ? OperandOwnership::GuaranteedForwardingPhi
+               ? OperandOwnership::GuaranteedForwarding
                : OperandOwnership::Reborrow;
   }
   return destBlockArgOwnershipKind.getForwardingOperandOwnership(

lib/SIL/IR/SILValue.cpp

@@ -432,8 +432,6 @@ StringRef OperandOwnership::asString() const {
     return "interior-pointer";
   case OperandOwnership::GuaranteedForwarding:
     return "guaranteed-forwarding";
-  case OperandOwnership::GuaranteedForwardingPhi:
-    return "guaranteed-forwarding-phi";
   case OperandOwnership::EndBorrow:
     return "end-borrow";
   case OperandOwnership::Reborrow:

lib/SIL/Utils/OwnershipUtils.cpp

@@ -53,8 +53,6 @@ bool swift::hasPointerEscape(BorrowedValue value) {
     case OperandOwnership::InteriorPointer:
     case OperandOwnership::BitwiseEscape:
       break;
-
-    case OperandOwnership::GuaranteedForwardingPhi:
     case OperandOwnership::Reborrow: {
       SILArgument *phi = cast<BranchInst>(op->getUser())
                              ->getDestBB()
@@ -225,6 +223,12 @@ bool swift::findInnerTransitiveGuaranteedUses(
         // Do not include transitive uses with 'none' ownership
         if (result->getOwnershipKind() == OwnershipKind::None)
           return true;
+        auto *phi = dyn_cast<SILPhiArgument>(result);
+        if (phi && phi->isPhi()) {
+          leafUse(use);
+          foundPointerEscape = true;
+          return true;
+        }
         for (auto *resultUse : result->getUses()) {
           if (resultUse->getOperandOwnership() != OperandOwnership::NonUse) {
             nonLeaf = true;
@@ -240,11 +244,6 @@ bool swift::findInnerTransitiveGuaranteedUses(
       }
       break;
     }
-    case OperandOwnership::GuaranteedForwardingPhi: {
-      leafUse(use);
-      foundPointerEscape = true;
-      break;
-    }
     case OperandOwnership::Borrow:
       // FIXME: Use visitExtendedScopeEndingUses and audit all clients to handle
       // reborrows.
@@ -342,17 +341,6 @@ bool swift::findExtendedUsesOfSimpleBorrowedValue(
       }
       recordUse(use);
       break;
-    // \p borrowedValue will dominate this GuaranteedForwardingPhi, because we
-    // return false in the case of Reborrow.
-    case OperandOwnership::GuaranteedForwardingPhi: {
-      SILArgument *phi = PhiOperand(use).getValue();
-      for (auto *use : phi->getUses()) {
-        if (use->getOperandOwnership() != OperandOwnership::NonUse)
-          worklist.insert(use);
-      }
-      recordUse(use);
-      break;
-    }
     case OperandOwnership::GuaranteedForwarding: {
       ForwardingOperand(use).visitForwardedValues([&](SILValue result) {
         // Do not include transitive uses with 'none' ownership
@@ -425,15 +413,12 @@ bool swift::visitGuaranteedForwardingPhisForSSAValue(
   // GuaranteedForwardingPhi uses.
   for (auto *use : value->getUses()) {
     if (use->getOperandOwnership() == OperandOwnership::GuaranteedForwarding) {
-      guaranteedForwardingOps.insert(use);
-      continue;
-    }
-    if (use->getOperandOwnership() ==
-        OperandOwnership::GuaranteedForwardingPhi) {
-      if (!visitor(use)) {
-        return false;
+      if (isa<BranchInst>(use->getUser())) {
+        if (!visitor(use)) {
+          return false;
+        }
       }
-      continue;
+      guaranteedForwardingOps.insert(use);
     }
   }
 
@@ -443,15 +428,12 @@ bool swift::visitGuaranteedForwardingPhisForSSAValue(
       for (auto *valUse : val->getUses()) {
         if (valUse->getOperandOwnership() ==
             OperandOwnership::GuaranteedForwarding) {
-          guaranteedForwardingOps.insert(valUse);
-          continue;
-        }
-        if (valUse->getOperandOwnership() ==
-            OperandOwnership::GuaranteedForwardingPhi) {
-          if (!visitor(valUse)) {
-            return false;
+          if (isa<BranchInst>(valUse->getUser())) {
+            if (!visitor(valUse)) {
+              return false;
+            }
           }
-          continue;
+          guaranteedForwardingOps.insert(valUse);
         }
       }
     }
@@ -1438,10 +1420,6 @@ ForwardingOperand::ForwardingOperand(Operand *use) {
   if (use->isTypeDependent())
     return;
 
-  if (!OwnershipForwardingMixin::isa(use->getUser())) {
-    return;
-  }
-#ifndef NDEBUG
   switch (use->getOperandOwnership()) {
   case OperandOwnership::ForwardingUnowned:
   case OperandOwnership::ForwardingConsume:
@@ -1456,12 +1434,12 @@ ForwardingOperand::ForwardingOperand(Operand *use) {
   case OperandOwnership::Borrow:
   case OperandOwnership::DestroyingConsume:
   case OperandOwnership::InteriorPointer:
-  case OperandOwnership::GuaranteedForwardingPhi:
   case OperandOwnership::EndBorrow:
   case OperandOwnership::Reborrow:
-    llvm_unreachable("this isn't the operand being forwarding!");
+    this->use = nullptr;
+    return;
   }
-#endif
+
   this->use = use;
 }
 
@@ -1668,15 +1646,23 @@ bool ForwardingOperand::visitForwardedValues(
   // "transforming terminators"... We know that this means that we should at
   // most have a single phi argument.
   auto *ti = cast<TermInst>(user);
-  return llvm::all_of(ti->getSuccessorBlocks(), [&](SILBasicBlock *succBlock) {
-    // If we do not have any arguments, then continue.
-    if (succBlock->args_empty())
-      return true;
+  if (ti->isTransformationTerminator()) {
+    return llvm::all_of(
+        ti->getSuccessorBlocks(), [&](SILBasicBlock *succBlock) {
+          // If we do not have any arguments, then continue.
+          if (succBlock->args_empty())
+            return true;
 
-    auto args = succBlock->getSILPhiArguments();
-    assert(args.size() == 1 && "Transforming terminator with multiple args?!");
-    return visitor(args[0]);
-  });
+          auto args = succBlock->getSILPhiArguments();
+          assert(args.size() == 1 &&
+                 "Transforming terminator with multiple args?!");
+          return visitor(args[0]);
+        });
+  }
+
+  auto *bi = cast<BranchInst>(ti);
+  auto *succArg = bi->getDestBB()->getArgument(use->getOperandNumber());
+  return visitor(succArg);
 }
 
 void swift::visitExtendedReborrowPhiBaseValuePairs(

lib/SIL/Utils/PrunedLiveness.cpp

@@ -318,10 +318,6 @@ PrunedLiveRange<LivenessWithDefs>::updateForDef(SILValue def) {
       updateForUse(use->getUser(), /*lifetimeEnding*/false);
       break;
     }
-    case OperandOwnership::GuaranteedForwardingPhi: {
-      updateForDef(PhiOperand(use).getValue());
-      break;
-    }
     default:
       updateForUse(use->getUser(), use->isLifetimeEnding());
       break;

lib/SIL/Verifier/LinearLifetimeChecker.cpp

@@ -317,7 +317,7 @@ void State::checkForSameBlockUseAfterFree(Operand *consumingUse,
     } else if (nonConsumingUse->getOperandOwnership() ==
                    OperandOwnership::Reborrow ||
                nonConsumingUse->getOperandOwnership() ==
-                   OperandOwnership::GuaranteedForwardingPhi) {
+                   OperandOwnership::GuaranteedForwarding) {
       continue;
     }
 

lib/SIL/Verifier/SILOwnershipVerifier.cpp

@@ -311,8 +311,8 @@ bool SILValueOwnershipChecker::gatherUsers(
       continue;
     }
 
-    if (op->getOperandOwnership() ==
-        OperandOwnership::GuaranteedForwardingPhi) {
+    if (PhiOperand(op) &&
+        op->getOperandOwnership() == OperandOwnership::GuaranteedForwarding) {
       LLVM_DEBUG(llvm::dbgs() << "Regular User: " << *user);
       nonLifetimeEndingUsers.push_back(op);
       continue;

lib/SILOptimizer/Mandatory/DiagnoseLifetimeIssues.cpp

@@ -215,7 +215,6 @@ visitUses(SILValue def, bool updateLivenessAndWeakStores, int callDepth) {
           liveness.updateForUse(user, /*lifetimeEnding*/ false);
         break;
       case OperandOwnership::GuaranteedForwarding:
-      case OperandOwnership::GuaranteedForwardingPhi:
       case OperandOwnership::ForwardingConsume:
         // TermInst includes ReturnInst, which is generally an escape.
         // If this is called as part of getArgumentState, then it is not really

lib/SILOptimizer/Mandatory/MoveKillsCopyableValuesChecker.cpp

@@ -164,10 +164,11 @@ bool CheckerLivenessInfo::compute() {
         // A forwarding borrow is validated as part of its parent borrow. So
         // just mark it as extending liveness and look through it.
         liveness.updateForUse(user, /*lifetimeEnding*/ false);
-        for (SILValue result : user->getResults()) {
+        ForwardingOperand(use).visitForwardedValues([&](SILValue result) {
           if (result->getOwnershipKind() == OwnershipKind::Guaranteed)
             defUseWorklist.insert(result);
-        }
+          return true;
+        });
         break;
       case OperandOwnership::InteriorPointer: {
         // An interior pointer user extends liveness until the end of the
@@ -191,7 +192,6 @@ bool CheckerLivenessInfo::compute() {
       case OperandOwnership::EndBorrow:
         // Don't care about this use.
         break;
-      case OperandOwnership::GuaranteedForwardingPhi:
       case OperandOwnership::Reborrow:
         // Reborrows do not occur this early in the pipeline.
         llvm_unreachable(

lib/SILOptimizer/Utils/CanonicalizeBorrowScope.cpp

@@ -275,7 +275,6 @@ bool CanonicalizeBorrowScope::visitBorrowScopeUses(SILValue innerValue,
         break;
 
       case OperandOwnership::GuaranteedForwarding:
-      case OperandOwnership::GuaranteedForwardingPhi:
       case OperandOwnership::ForwardingConsume:
         if (CanonicalizeBorrowScope::isRewritableOSSAForward(user)) {
           if (!visitor.visitForwardingUse(use)) {

lib/SILOptimizer/Utils/CanonicalizeOSSALifetime.cpp

@@ -192,7 +192,6 @@ bool CanonicalizeOSSALifetime::computeCanonicalLiveness() {
         // reborrow of such.
         liveness.updateForUse(user, /*lifetimeEnding*/ false);
         break;
-      case OperandOwnership::GuaranteedForwardingPhi:
       case OperandOwnership::Reborrow:
         BranchInst *branch;
         if (!(branch = dyn_cast<BranchInst>(user))) {