Add new apis to OwnershipLifetimeExtender

Author: meg-gupta

lib/SILOptimizer/Utils/OwnershipOptUtils.cpp

@@ -643,6 +643,12 @@ struct OwnershipLifetimeExtender {
                                SILBasicBlock::iterator borrowPoint,
                                RangeTy guaranteedUsePoints);
 
+  template <typename RangeTy>
+  BeginBorrowInst *
+  borrowCopyOverGuaranteedUsers(SILValue newValue,
+                                SILBasicBlock::iterator borrowPoint,
+                                RangeTy guaranteedUsers);
+
   /// Borrow \p newValue over the lifetime of \p guaranteedValue. Return the
   /// new guaranteed value.
   SILValue borrowOverValue(SILValue newValue, SILValue guaranteedValue);
@@ -654,6 +660,10 @@ struct OwnershipLifetimeExtender {
   /// the BorrowedValue that begins the scope.
   SILValue borrowOverSingleUse(SILValue newValue,
                                Operand *singleGuaranteedUse);
+
+  SILValue
+  borrowOverSingleNonLifetimeEndingUser(SILValue newValue,
+                                        SILInstruction *nonLifetimeEndingUser);
 };
 
 } // end anonymous namespace
@@ -780,9 +790,9 @@ OwnershipLifetimeExtender::borrowCopyOverScope(SILValue newValue,
 ///
 /// Precondition: None of \p guaranteedUses are lifetime ending.
 template <typename RangeTy>
-BeginBorrowInst *OwnershipLifetimeExtender::borrowCopyOverGuaranteedUses(
+BeginBorrowInst *OwnershipLifetimeExtender::borrowCopyOverGuaranteedUsers(
     SILValue newValue, SILBasicBlock::iterator borrowPoint,
-    RangeTy guaranteedUsePoints) {
+    RangeTy guaranteedUsers) {
 
   auto loc = RegularLocation::getAutoGeneratedLocation(borrowPoint->getLoc());
 
@@ -794,12 +804,11 @@ BeginBorrowInst *OwnershipLifetimeExtender::borrowCopyOverGuaranteedUses(
 
   // Create end_borrows at the end of the borrow's lifetime.
   {
-    // We don't expect an empty guaranteedUsePoints. If it happens, then the
+    // We don't expect an empty guaranteedUsers. If it happens, then the
     // newly created copy will never be destroyed.
-    assert(!guaranteedUsePoints.empty());
+    assert(!guaranteedUsers.empty());
 
-    auto opRange = makeUserRange(guaranteedUsePoints);
-    ValueLifetimeAnalysis lifetimeAnalysis(borrow, opRange);
+    ValueLifetimeAnalysis lifetimeAnalysis(borrow, guaranteedUsers);
     ValueLifetimeBoundary borrowBoundary;
     lifetimeAnalysis.computeLifetimeBoundary(borrowBoundary);
 
@@ -834,6 +843,14 @@ BeginBorrowInst *OwnershipLifetimeExtender::borrowCopyOverGuaranteedUses(
   return borrow;
 }
 
+template <typename RangeTy>
+BeginBorrowInst *OwnershipLifetimeExtender::borrowCopyOverGuaranteedUses(
+    SILValue newValue, SILBasicBlock::iterator borrowPoint,
+    RangeTy guaranteedUsePoints) {
+  return borrowCopyOverGuaranteedUsers(newValue, borrowPoint,
+                                       makeUserRange(guaranteedUsePoints));
+}
+
 // Return the borrow position when replacing guaranteedValue with newValue.
 //
 // Precondition: newValue's block dominates and reaches guaranteedValue's block.
@@ -944,6 +961,18 @@ OwnershipLifetimeExtender::borrowOverSingleUse(SILValue newValue,
   return newBeginBorrow;
 }
 
+SILValue OwnershipLifetimeExtender::borrowOverSingleNonLifetimeEndingUser(
+    SILValue newValue, SILInstruction *nonLifetimeEndingUser) {
+  // Avoid borrowing guaranteed function arguments.
+  if (isa<SILFunctionArgument>(newValue) &&
+      newValue.getOwnershipKind() == OwnershipKind::Guaranteed) {
+    return newValue;
+  }
+  auto borrowPt = newValue->getNextInstruction()->getIterator();
+  return borrowCopyOverGuaranteedUsers(
+      newValue, borrowPt, ArrayRef<SILInstruction *>(nonLifetimeEndingUser));
+}
+
 //===----------------------------------------------------------------------===//
 //                OwnershipRAUWUtility - RAUW + fix ownership
 //===----------------------------------------------------------------------===//