diff --git a/include/swift/SIL/SILInstruction.h b/include/swift/SIL/SILInstruction.h
index 8ae478342f3..92d94f57cc7 100644
--- a/include/swift/SIL/SILInstruction.h
+++ b/include/swift/SIL/SILInstruction.h
@@ -6741,13 +6741,12 @@ public:
 };
 
 /// A switch on a value of a builtin type.
-class SwitchValueInst
-    : public InstructionBase<SILInstructionKind::SwitchValueInst,
-                             TermInst> {
+class SwitchValueInst final
+    : public InstructionBaseWithTrailingOperands<
+                                      SILInstructionKind::SwitchValueInst,
+                                      SwitchValueInst, TermInst, SILSuccessor> {
   friend SILBuilder;
 
-  TailAllocatedOperandList<1> Operands;
-
   SwitchValueInst(SILDebugLocation DebugLoc, SILValue Operand,
                   SILBasicBlock *DefaultBB, ArrayRef<SILValue> Cases,
                   ArrayRef<SILBasicBlock *> BBs);
@@ -6759,16 +6758,15 @@ class SwitchValueInst
   //   destinations for each case, ending with the default destination if
   //   present.
 
-
   OperandValueArrayRef getCaseBuf() const {
-    return Operands.getDynamicValuesAsArray();
+    return OperandValueArrayRef(getAllOperands().slice(1));
   }
 
   SILSuccessor *getSuccessorBuf() {
-    return reinterpret_cast<SILSuccessor*>(Operands.asArray().end());
+    return getTrailingObjects<SILSuccessor>();
   }
   const SILSuccessor *getSuccessorBuf() const {
-    return reinterpret_cast<const SILSuccessor *>(Operands.asArray().end());
+    return getTrailingObjects<SILSuccessor>();
   }
 
   static SwitchValueInst *
@@ -6780,10 +6778,7 @@ public:
   /// Clean up tail-allocated successor records for the switch cases.
   ~SwitchValueInst();
 
-  SILValue getOperand() const { return Operands[0].get(); }
-
-  ArrayRef<Operand> getAllOperands() const { return Operands.asArray(); }
-  MutableArrayRef<Operand> getAllOperands() { return Operands.asArray(); }
+  SILValue getOperand() const { return getAllOperands()[0].get(); }
 
   SuccessorListTy getSuccessors() {
     return MutableArrayRef<SILSuccessor>{getSuccessorBuf(),
@@ -6791,7 +6786,7 @@ public:
   }
 
   unsigned getNumCases() const {
-    return SILInstruction::Bits.SwitchValueInst.NumCases;
+    return getAllOperands().size() - 1;
   }
   std::pair<SILValue, SILBasicBlock*>
   getCase(unsigned i) const {
diff --git a/include/swift/SIL/SILNode.h b/include/swift/SIL/SILNode.h
index 978a4fa96e4..e527e9399bd 100644
--- a/include/swift/SIL/SILNode.h
+++ b/include/swift/SIL/SILNode.h
@@ -307,10 +307,8 @@ protected:
   IBWTO_BITFIELD(BranchInst, TermInst, 0, : NumPadBits);
   // Ensure that YieldInst bitfield does not overflow.
   IBWTO_BITFIELD(YieldInst, TermInst, 0, : NumPadBits);
-  SWIFT_INLINE_BITFIELD_FULL(SwitchValueInst, TermInst, 1+32,
-    HasDefault : 1,
-    : NumPadBits,
-    NumCases : 32
+  IBWTO_BITFIELD(SwitchValueInst, TermInst, 1,
+    HasDefault : 1
   );
   SWIFT_INLINE_BITFIELD_FULL(SwitchEnumInstBase, TermInst, 1+32,
     HasDefault : 1,
diff --git a/lib/SIL/SILInstructions.cpp b/lib/SIL/SILInstructions.cpp
index a9d7153822c..b348d323db9 100644
--- a/lib/SIL/SILInstructions.cpp
+++ b/lib/SIL/SILInstructions.cpp
@@ -1262,9 +1262,8 @@ SwitchValueInst::SwitchValueInst(SILDebugLocation Loc, SILValue Operand,
                                  SILBasicBlock *DefaultBB,
                                  ArrayRef<SILValue> Cases,
                                  ArrayRef<SILBasicBlock *> BBs)
-    : InstructionBase(Loc), Operands(this, Cases, Operand) {
+    : InstructionBaseWithTrailingOperands(Operand, Cases, Loc) {
   SILInstruction::Bits.SwitchValueInst.HasDefault = bool(DefaultBB);
-  SILInstruction::Bits.SwitchValueInst.NumCases = Cases.size();
   // Initialize the successor array.
   auto *succs = getSuccessorBuf();
   unsigned OperandBitWidth = 0;
@@ -1324,10 +1323,9 @@ SwitchValueInst *SwitchValueInst::create(
     Cases.push_back(pair.first);
     BBs.push_back(pair.second);
   }
-  size_t bufSize = sizeof(SwitchValueInst) +
-                   decltype(Operands)::getExtraSize(Cases.size()) +
-                   sizeof(SILSuccessor) * numSuccessors;
-  void *buf = F.getModule().allocateInst(bufSize, alignof(SwitchValueInst));
+  auto size = totalSizeToAlloc<swift::Operand, SILSuccessor>(numCases + 1,
+                                                             numSuccessors);
+  auto buf = F.getModule().allocateInst(size, alignof(SwitchValueInst));
   return ::new (buf) SwitchValueInst(Loc, Operand, DefaultBB, Cases, BBs);
 }