handle upcast instructions in statically initialized globals

This allows statically initialized multi-dimensional arrays in embedded swift.

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/Utilities/OptUtils.swift

@@ -370,6 +370,7 @@ extension Instruction {
          is VectorInst,
          is AllocVectorInst,
          is UncheckedRefCastInst,
+         is UpcastInst,
          is ValueToBridgeObjectInst,
          is ConvertFunctionInst,
          is ThinToThickFunctionInst,

include/swift/SIL/SILBuilder.h

@@ -1251,6 +1251,10 @@ class SILBuilder {
   UpcastInst *createUpcast(SILLocation Loc, SILValue Op, SILType Ty,
                            ValueOwnershipKind forwardingOwnershipKind) {
     assert(Ty.isObject());
+    if (isInsertingIntoGlobal()) {
+      return insert(UpcastInst::create(getSILDebugLocation(Loc), Op, Ty,
+                                       getModule(), forwardingOwnershipKind));
+    }
     return insert(UpcastInst::create(getSILDebugLocation(Loc), Op, Ty,
                                      getFunction(), forwardingOwnershipKind));
   }

include/swift/SIL/SILInstruction.h

@@ -5879,6 +5879,10 @@ class UpcastInst final : public UnaryInstructionWithTypeDependentOperandsBase<
                                                       forwardingOwnershipKind) {
   }
 
+  static UpcastInst *create(SILDebugLocation DebugLoc, SILValue Operand,
+                            SILType Ty, SILModule &Mod,
+                            ValueOwnershipKind forwardingOwnershipKind);
+
   static UpcastInst *create(SILDebugLocation DebugLoc, SILValue Operand,
                             SILType Ty, SILFunction &F,
                             ValueOwnershipKind forwardingOwnershipKind);

lib/IRGen/GenConstant.cpp

@@ -358,6 +358,9 @@ Explosion irgen::emitConstantValue(IRGenModule &IGM, SILValue operand,
   } else if (auto *URCI = dyn_cast<UncheckedRefCastInst>(operand)) {
     return emitConstantValue(IGM, URCI->getOperand(), flatten);
 
+  } else if (auto *UCI = dyn_cast<UpcastInst>(operand)) {
+    return emitConstantValue(IGM, UCI->getOperand(), flatten);
+
   } else if (auto *T2TFI = dyn_cast<ThinToThickFunctionInst>(operand)) {
     SILType type = operand->getType();
     auto *sTy = cast<llvm::StructType>(IGM.getTypeInfo(type).getStorageType());

lib/SIL/IR/SILInstructions.cpp

@@ -2714,6 +2714,15 @@ MetatypeInst *MetatypeInst::create(SILDebugLocation Loc, SILType Ty,
   return ::new (Buffer) MetatypeInst(Loc, Ty, TypeDependentOperands);
 }
 
+UpcastInst *UpcastInst::create(SILDebugLocation DebugLoc, SILValue Operand,
+                               SILType Ty, SILModule &Mod,
+                               ValueOwnershipKind forwardingOwnershipKind) {
+  unsigned size = totalSizeToAlloc<swift::Operand>(1);
+  void *Buffer = Mod.allocateInst(size, alignof(UpcastInst));
+  return ::new (Buffer) UpcastInst(DebugLoc, Operand, {}, Ty,
+                                   forwardingOwnershipKind);
+}
+
 UpcastInst *UpcastInst::create(SILDebugLocation DebugLoc, SILValue Operand,
                                SILType Ty, SILFunction &F,
                                ValueOwnershipKind forwardingOwnershipKind) {