LargeTypesReg2Mem: Don't ignore BuiltinFixedArrayType

rdar://139457907

Author: aschwaighofer

lib/IRGen/LoadableByAddress.cpp

@@ -123,7 +123,7 @@ static bool isLargeLoadableType(GenericEnvironment *GenericEnv, SILType t,
     canType = GenericEnv->mapTypeIntoContext(canType)->getCanonicalType();
   }
 
-  if (canType.getAnyGeneric()) {
+  if (canType.getAnyGeneric() || t.is<BuiltinFixedArrayType>()) {
     assert(t.isObject() && "Expected only two categories: address and object");
     assert(!canType->hasTypeParameter());
     const TypeInfo &TI = Mod.getTypeInfoForLowered(canType);
@@ -3514,7 +3514,7 @@ class LargeLoadableHeuristic {
       canType = genEnv->mapTypeIntoContext(canType)->getCanonicalType();
     }
 
-    if (canType.getAnyGeneric() || isa<TupleType>(canType)) {
+    if (canType.getAnyGeneric() || isa<TupleType>(canType) || ty.is<BuiltinFixedArrayType>()) {
       assert(ty.isObject() &&
              "Expected only two categories: address and object");
       assert(!canType->hasTypeParameter());

lib/SIL/IR/TypeLowering.cpp

@@ -5264,6 +5264,16 @@ static void countNumberOfInnerFields(unsigned &fieldsCount, TypeConverter &TC,
     }
     return;
   }
+
+  if (auto fixedArrayTy = Ty.getAs<BuiltinFixedArrayType>()) {
+    auto fixedSize = fixedArrayTy->getFixedInhabitedSize();
+    if (fixedSize.has_value() && !fixedArrayTy->isFixedNegativeSize() )
+      fieldsCount += *fixedSize;
+    else
+      fieldsCount += 1;
+    return;
+  }
+
   if (auto *enumDecl = Ty.getEnumOrBoundGenericEnum()) {
     if (enumDecl->isIndirect()) {
       return;

test/IRGen/loadable_by_address_reg2mem_fixed_array.sil

@@ -0,0 +1,36 @@
+// %target-swift-frontend %s  -Xllvm -sil-print-after=loadable-address -import-objc-header %S/Inputs/large_c.h -c -o %t/t.o 2>&1 | %FileCheck %s
+
+// RUN: %target-swift-frontend %s -disable-availability-checking -enable-experimental-feature ValueGenerics -enable-experimental-feature BuiltinModule  -Xllvm -sil-print-after=loadable-address -c -o %t/t.o 2>&1 | %FileCheck %s
+
+// REQUIRES: swift_feature_BuiltinModule
+// REQUIRES: swift_feature_ValueGenerics
+
+import Builtin
+import Swift
+
+
+sil_stage canonical
+
+// CHECK: sil @test1 : $@convention(thin) (@in_guaranteed Builtin.FixedArray<16, Builtin.Int64>) -> () {
+// CHECK-NOT: load
+// CHECK-NOT: store
+// CHECK:   alloc_stack $Builtin.FixedArray<16, Builtin.Int64>
+// CHECK-NOT: load
+// CHECK-NOT: store
+// CHECK:   copy_addr [take] {{.*}} to [init] {{.*}} : $*Builtin.FixedArray<16, Builtin.Int64>
+// CHECK-NOT: load
+// CHECK-NOT: store
+// CHECK: } // end sil function 'test1'
+
+sil @test1 : $@convention(thin) (Builtin.FixedArray<16, Builtin.Int64>) -> () {
+bb0(%0 : $Builtin.FixedArray<16, Builtin.Int64>):
+  %1 = alloc_stack $Builtin.FixedArray<16, Builtin.Int64>
+  %2 = alloc_stack $Builtin.FixedArray<16, Builtin.Int64>
+  store %0 to %1 : $*Builtin.FixedArray<16, Builtin.Int64>
+  %3 = load %1 : $*Builtin.FixedArray<16, Builtin.Int64>
+  store %3 to %2 : $*Builtin.FixedArray<16, Builtin.Int64>
+  dealloc_stack %2 : $*Builtin.FixedArray<16, Builtin.Int64>
+  dealloc_stack %1 : $*Builtin.FixedArray<16, Builtin.Int64>
+  %t = tuple ()
+  return %t : $()
+}