diff --git a/flang/runtime/unit.h → FortranRuntime/lib/Runtime/unit.h b/flang/runtime/unit.h → FortranRuntime/lib/Runtime/unit.h
@@ -1,4 +1,4 @@
-//===-- runtime/unit.h ------------------------------------------*- C++ -*-===//
+//===-- lib/Runtime/unit.h --------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -8,21 +8,21 @@
 
 // Fortran external I/O units
 
-#ifndef FORTRAN_RUNTIME_IO_UNIT_H_
-#define FORTRAN_RUNTIME_IO_UNIT_H_
+#ifndef FORTRAN_RUNTIME_UNIT_H_
+#define FORTRAN_RUNTIME_UNIT_H_
 
 #include "buffer.h"
 #include "connection.h"
 #include "environment.h"
 #include "file.h"
+#include "flang/Common/constexpr-bitset.h"
+#include "flang/Common/optional.h"
+#include "flang/Runtime/memory.h"
 #include "format.h"
 #include "io-error.h"
 #include "io-stmt.h"
 #include "lock.h"
 #include "terminator.h"
-#include "flang/Common/constexpr-bitset.h"
-#include "flang/Common/optional.h"
-#include "flang/Runtime/memory.h"
 #include <cstdlib>
 #include <cstring>
 #include <flang/Common/variant.h>
@@ -291,4 +291,4 @@ class ChildIo {
 };
 
 } // namespace Fortran::runtime::io
-#endif // FORTRAN_RUNTIME_IO_UNIT_H_
+#endif /* FORTRAN_RUNTIME_UNIT_H_ */
diff --git a/flang/runtime/utf.cpp → FortranRuntime/lib/Runtime/utf.cpp b/flang/runtime/utf.cpp → FortranRuntime/lib/Runtime/utf.cpp
@@ -1,4 +1,4 @@
-//===-- runtime/utf.cpp ---------------------------------------------------===//
+//===-- lib/Runtime/utf.cpp -------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/runtime/utf.h → FortranRuntime/lib/Runtime/utf.h b/flang/runtime/utf.h → FortranRuntime/lib/Runtime/utf.h
@@ -1,4 +1,4 @@
-//===-- runtime/utf.h -----------------------------------------------------===//
+//===-- lib/Runtime/utf.h ---------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -70,4 +70,4 @@ RT_API_ATTRS Fortran::common::optional<char32_t> DecodeUTF8(const char *);
 RT_API_ATTRS std::size_t EncodeUTF8(char *, char32_t);
 
 } // namespace Fortran::runtime
-#endif // FORTRAN_RUNTIME_UTF_H_
+#endif /* FORTRAN_RUNTIME_UTF_H_ */
diff --git a/flang/unittests/Evaluate/fp-testing.cpp → FortranRuntime/lib/Testing/fp-testing.cpp b/flang/unittests/Evaluate/fp-testing.cpp → FortranRuntime/lib/Testing/fp-testing.cpp
@@ -1,4 +1,12 @@
-#include "fp-testing.h"
+//===-- lib/Testing/fp-testing.cpp ------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Testing/fp-testing.h"
 #include "llvm/Support/Errno.h"
 #include <cstdio>
 #include <cstdlib>
@@ -8,7 +16,7 @@
 #endif
 
 using Fortran::common::RoundingMode;
-using Fortran::evaluate::RealFlag;
+using Fortran::common::RealFlag;
 
 ScopedHostFloatingPointEnvironment::ScopedHostFloatingPointEnvironment(
 #if __x86_64__

diff --git a/flang/unittests/Evaluate/testing.cpp → FortranRuntime/lib/Testing/testing.cpp b/flang/unittests/Evaluate/testing.cpp → FortranRuntime/lib/Testing/testing.cpp
@@ -1,4 +1,12 @@
-#include "testing.h"
+//===-- lib/Testing/testing.cpp ---------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Testing/testing.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdarg>
 #include <cstdio>

diff --git a/flang/test/Driver/ctofortran.f90 → FortranRuntime/test/Driver/ctofortran.f90 b/flang/test/Driver/ctofortran.f90 → FortranRuntime/test/Driver/ctofortran.f90
diff --git a/flang/test/Driver/exec.f90 → FortranRuntime/test/Driver/exec.f90 b/flang/test/Driver/exec.f90 → FortranRuntime/test/Driver/exec.f90
diff --git a/flang/test/Runtime/no-cpp-dep.c → FortranRuntime/test/Runtime/no-cpp-dep.c b/flang/test/Runtime/no-cpp-dep.c → FortranRuntime/test/Runtime/no-cpp-dep.c
diff --git a/FortranRuntime/unittests/Common/CMakeLists.txt b/FortranRuntime/unittests/Common/CMakeLists.txt
@@ -0,0 +1,11 @@
+#===-- unittests/Common/CMakeLists.txt -------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
+add_flang_unittest(FlangCommonTests
+  FastIntSetTest.cpp
+)
diff --git a/flang/unittests/Common/FastIntSetTest.cpp → ...ntime/unittests/Common/FastIntSetTest.cpp b/flang/unittests/Common/FastIntSetTest.cpp → ...ntime/unittests/Common/FastIntSetTest.cpp
@@ -1,13 +1,13 @@
-//===-- flang/unittests/Common/FastIntSetTest.cpp ---------------*- C++ -*-===//
+//===-- unittests/Common/FastIntSetTest.cpp ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
 #include "flang/Common/fast-int-set.h"
+#include "gtest/gtest.h"
 #include <optional>
 
 TEST(FastIntSetTests, Sanity) {

diff --git a/FortranRuntime/unittests/Decimal/CMakeLists.txt b/FortranRuntime/unittests/Decimal/CMakeLists.txt
@@ -0,0 +1,18 @@
+#===-- unittests/Decimal/CMakeLists.txt ------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+add_flang_nongtest_unittest(quick-sanity-test
+  FortranDecimal
+)
+
+# This test is not run by default as it takes a long time to execute.
+add_flang_nongtest_unittest(thorough-test
+  SLOW_TEST
+  FortranDecimal
+)
diff --git a/...g/unittests/Decimal/quick-sanity-test.cpp → ...e/unittests/Decimal/quick-sanity-test.cpp b/...g/unittests/Decimal/quick-sanity-test.cpp → ...e/unittests/Decimal/quick-sanity-test.cpp
@@ -1,4 +1,12 @@
-#include "flang/Decimal/decimal.h"
+//===-- unittests/Decimal/quick-sanity-test.cpp -----------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Common/decimal.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cinttypes>
 #include <cstdio>

diff --git a/flang/unittests/Decimal/thorough-test.cpp → ...ntime/unittests/Decimal/thorough-test.cpp b/flang/unittests/Decimal/thorough-test.cpp → ...ntime/unittests/Decimal/thorough-test.cpp
@@ -1,4 +1,12 @@
-#include "flang/Decimal/decimal.h"
+//===-- unittests/Decimal/thorough-test.cpp ---------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Common/decimal.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cinttypes>
 #include <cstdio>

diff --git a/FortranRuntime/unittests/Evaluate/CMakeLists.txt b/FortranRuntime/unittests/Evaluate/CMakeLists.txt
@@ -0,0 +1,14 @@
+#===-- unittests/Evaluate/CMakeLists.txt -----------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
+add_flang_nongtest_unittest(reshape
+  FortranEvaluateTesting
+  FortranSemantics
+  FortranEvaluate
+  FortranRuntime
+)
diff --git a/...nittests/Evaluate/ISO-Fortran-binding.cpp → ...nittests/Evaluate/ISO-Fortran-binding.cpp b/...nittests/Evaluate/ISO-Fortran-binding.cpp → ...nittests/Evaluate/ISO-Fortran-binding.cpp
@@ -1,6 +1,14 @@
-#include "testing.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+//===-- unittests/Evaluate/ISO-Fortran-binding.cpp --------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor.h"
+#include "flang/Testing/testing.h"
 #include "llvm/Support/raw_ostream.h"
 #include <type_traits>
 

diff --git a/flang/unittests/Evaluate/reshape.cpp → ...ranRuntime/unittests/Evaluate/reshape.cpp b/flang/unittests/Evaluate/reshape.cpp → ...ranRuntime/unittests/Evaluate/reshape.cpp
@@ -1,6 +1,14 @@
-#include "testing.h"
+//===-- unittests/Evaluate/reshape.cpp --------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/transformational.h"
+#include "flang/Testing/testing.h"
 #include <cinttypes>
 
 using namespace Fortran::common;

diff --git a/flang/unittests/Runtime/AccessTest.cpp → ...nRuntime/unittests/Runtime/AccessTest.cpp b/flang/unittests/Runtime/AccessTest.cpp → ...nRuntime/unittests/Runtime/AccessTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/AccessTest.cpp ----------------------------===//
+//===-- unittests/Runtime/AccessTest.cpp ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,9 +10,9 @@
 #ifndef _WIN32
 
 #include "CrashHandlerFixture.h"
-#include "gtest/gtest.h"
 #include "flang/Runtime/extensions.h"
 #include "llvm/ADT/Twine.h"
+#include "gtest/gtest.h"
 
 #include <fcntl.h>
 #include <sys/stat.h>

diff --git a/flang/unittests/Runtime/Allocatable.cpp → ...Runtime/unittests/Runtime/Allocatable.cpp b/flang/unittests/Runtime/Allocatable.cpp → ...Runtime/unittests/Runtime/Allocatable.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Allocatable.cpp--------- ---------*- C++-*-===//
+//===-- unittests/Runtime/Allocatable.cpp -----------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,8 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/allocatable.h"
-#include "gtest/gtest.h"
 #include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 

diff --git a/flang/unittests/Runtime/ArrayConstructor.cpp → ...me/unittests/Runtime/ArrayConstructor.cpp b/flang/unittests/Runtime/ArrayConstructor.cpp → ...me/unittests/Runtime/ArrayConstructor.cpp
@@ -1,18 +1,18 @@
-//===-- flang/unittests/Runtime/ArrayConstructor.cpp-------------*- C++ -*-===//
+//===-- unittests/Runtime/ArrayConstructor.cpp ------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/array-constructor.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 #include <memory>
 

diff --git a/flang/unittests/Runtime/BufferTest.cpp → ...nRuntime/unittests/Runtime/BufferTest.cpp b/flang/unittests/Runtime/BufferTest.cpp → ...nRuntime/unittests/Runtime/BufferTest.cpp
@@ -1,12 +1,12 @@
-//===-- flang/unittests/Runtime/BufferTest.cpp ------------------*- C++ -*-===//
+//===-- unittests/Runtime/BufferTest.cpp ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "../../runtime/buffer.h"
+#include "../../lib/Runtime/buffer.h"
 #include "CrashHandlerFixture.h"
 #include "gtest/gtest.h"
 #include <algorithm>

diff --git a/flang/unittests/Runtime/CMakeLists.txt → ...nRuntime/unittests/Runtime/CMakeLists.txt b/flang/unittests/Runtime/CMakeLists.txt → ...nRuntime/unittests/Runtime/CMakeLists.txt
@@ -1,3 +1,11 @@
+#===-- unittests/Runtime/CMakeLists.txt ------------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
 add_flang_unittest(FlangRuntimeTests
   AccessTest.cpp
   Allocatable.cpp

diff --git a/...g/unittests/Runtime/CUDA/AllocatorCUF.cpp → ...e/unittests/Runtime/CUDA/AllocatorCUF.cpp b/...g/unittests/Runtime/CUDA/AllocatorCUF.cpp → ...e/unittests/Runtime/CUDA/AllocatorCUF.cpp
@@ -1,18 +1,18 @@
-//===-- flang/unittests/Runtime/AllocatableCUF.cpp ---------------*- C++-*-===//
+//===-- unittests/Runtime/CUDA/AllocatorCUF.cpp -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
 #include "../../../runtime/terminator.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Runtime/CUDA/allocator.h"
 #include "flang/Runtime/CUDA/descriptor.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/allocator-registry.h"
+#include "flang/Support/Fortran.h"
+#include "gtest/gtest.h"
 
 #include "cuda_runtime.h"
 

diff --git a/FortranRuntime/unittests/Runtime/CUDA/CMakeLists.txt b/FortranRuntime/unittests/Runtime/CUDA/CMakeLists.txt
@@ -0,0 +1,23 @@
+#===-- unittests/Runtime/CUDA/CMakeLists.txt -------------------------------===#
+#
+# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+#===------------------------------------------------------------------------===#
+
+if (FLANG_CUF_RUNTIME)
+
+add_flang_unittest(FlangCufRuntimeTests
+  AllocatorCUF.cpp
+)
+
+target_link_libraries(FlangCufRuntimeTests
+  PRIVATE
+  CufRuntime_cuda_${CUDAToolkit_VERSION_MAJOR}
+  FortranRuntime
+)
+
+target_include_directories(FlangCufRuntimeTests PRIVATE ${CUDAToolkit_INCLUDE_DIRS})
+
+endif()
diff --git a/flang/unittests/Runtime/CharacterTest.cpp → ...ntime/unittests/Runtime/CharacterTest.cpp b/flang/unittests/Runtime/CharacterTest.cpp → ...ntime/unittests/Runtime/CharacterTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/CharacterTest.cpp ---------------*- C++ -*-===//
+//===-- unittests/Runtime/CharacterTest.cpp ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,8 +10,8 @@
 // in Fortran.
 
 #include "flang/Runtime/character.h"
-#include "gtest/gtest.h"
 #include "flang/Runtime/descriptor.h"
+#include "gtest/gtest.h"
 #include <cstring>
 #include <functional>
 #include <tuple>

diff --git a/flang/unittests/Runtime/CommandTest.cpp → ...Runtime/unittests/Runtime/CommandTest.cpp b/flang/unittests/Runtime/CommandTest.cpp → ...Runtime/unittests/Runtime/CommandTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/CommandTest.cpp ---------------------------===//
+//===-- unittests/Runtime/CommandTest.cpp -----------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,12 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/command.h"
-#include "gmock/gmock.h"
-#include "gtest/gtest.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/execute.h"
 #include "flang/Runtime/extensions.h"
 #include "flang/Runtime/main.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
 #include <cstddef>
 #include <cstdlib>
 

diff --git a/flang/unittests/Runtime/Complex.cpp → FortranRuntime/unittests/Runtime/Complex.cpp b/flang/unittests/Runtime/Complex.cpp → FortranRuntime/unittests/Runtime/Complex.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Complex.cpp ---------------------*- C++ -*-===//
+//===-- unittests/Runtime/Complex.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -13,7 +13,7 @@
 #pragma clang diagnostic ignored "-Wc99-extensions"
 #endif
 
-#include "flang/Common/Fortran.h"
+#include "flang/Common/Fortran-consts.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/entry-names.h"
 

diff --git a/...unittests/Runtime/CrashHandlerFixture.cpp → ...unittests/Runtime/CrashHandlerFixture.cpp b/...unittests/Runtime/CrashHandlerFixture.cpp → ...unittests/Runtime/CrashHandlerFixture.cpp
@@ -1,12 +1,12 @@
-//===-- flang/unittests/Runtime/CrashHandlerFixture.cpp ---------*- C++ -*-===//
+//===-- unittests/Runtime/CrashHandlerFixture.cpp ---------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 #include "CrashHandlerFixture.h"
-#include "../../runtime/terminator.h"
+#include "../../lib/Runtime/terminator.h"
 #include <cstdarg>
 #include <cstdlib>
 

diff --git a/...g/unittests/Runtime/CrashHandlerFixture.h → ...e/unittests/Runtime/CrashHandlerFixture.h b/...g/unittests/Runtime/CrashHandlerFixture.h → ...e/unittests/Runtime/CrashHandlerFixture.h
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/CrashHandlerFixture.h -----------*- C++ -*-===//
+//===-- unittests/Runtime/CrashHandlerFixture.h -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,12 +10,12 @@
 /// with expected message.
 //
 //===----------------------------------------------------------------------===//
-#ifndef LLVM_FLANG_UNITTESTS_RUNTIMEGTEST_CRASHHANDLERFIXTURE_H
-#define LLVM_FLANG_UNITTESTS_RUNTIMEGTEST_CRASHHANDLERFIXTURE_H
+#ifndef FORTRAN_UNITTESTS_RUNTIME_CRASHHANDLERFIXTURE_H_
+#define FORTRAN_UNITTESTS_RUNTIME_CRASHHANDLERFIXTURE_H_
 #include <gtest/gtest.h>
 
 struct CrashHandlerFixture : testing::Test {
   void SetUp();
 };
 
-#endif
+#endif /* FORTRAN_UNITTESTS_RUNTIME_CRASHHANDLERFIXTURE_H_ */
diff --git a/flang/unittests/Runtime/Derived.cpp → FortranRuntime/unittests/Runtime/Derived.cpp b/flang/unittests/Runtime/Derived.cpp → FortranRuntime/unittests/Runtime/Derived.cpp
@@ -1,15 +1,15 @@
-//===-- flang/unittests/Runtime/Pointer.cpp--------- -------------*- C++-*-===//
+//===-- unittests/Runtime/Derived.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/derived-api.h"
 #include "flang/Runtime/descriptor.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 

diff --git a/flang/unittests/Runtime/ExternalIOTest.cpp → ...time/unittests/Runtime/ExternalIOTest.cpp b/flang/unittests/Runtime/ExternalIOTest.cpp → ...time/unittests/Runtime/ExternalIOTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/RuntimeGTest/ExternalIOTest.cpp ---------*- C++ -*-===//
+//===-- unittests/Runtime/ExternalIOTest.cpp --------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -11,12 +11,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "CrashHandlerFixture.h"
-#include "gtest/gtest.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/io-api.h"
 #include "flang/Runtime/main.h"
 #include "flang/Runtime/stop.h"
 #include "llvm/Support/raw_ostream.h"
+#include "gtest/gtest.h"
 #include <cstring>
 #include <string_view>
 

diff --git a/flang/unittests/Runtime/Format.cpp → FortranRuntime/unittests/Runtime/Format.cpp b/flang/unittests/Runtime/Format.cpp → FortranRuntime/unittests/Runtime/Format.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Format.cpp ----------------------*- C++ -*-===//
+//===-- unittests/Runtime/Format.cpp ----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,9 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "CrashHandlerFixture.h"
-#include "../runtime/connection.h"
-#include "../runtime/format-implementation.h"
-#include "../runtime/io-error.h"
+#include "../../lib/Runtime/connection.h"
+#include "../../lib/Runtime/format-implementation.h"
+#include "../../lib/Runtime/io-error.h"
 #include <optional>
 #include <string>
 #include <tuple>

diff --git a/flang/unittests/Runtime/Inquiry.cpp → FortranRuntime/unittests/Runtime/Inquiry.cpp b/flang/unittests/Runtime/Inquiry.cpp → FortranRuntime/unittests/Runtime/Inquiry.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Inquiry.cpp -------------------------------===//
+//===-- unittests/Runtime/Inquiry.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,9 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/inquiry.h"
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 using Fortran::common::TypeCategory;

diff --git a/flang/unittests/Runtime/ListInputTest.cpp → ...ntime/unittests/Runtime/ListInputTest.cpp b/flang/unittests/Runtime/ListInputTest.cpp → ...ntime/unittests/Runtime/ListInputTest.cpp
@@ -1,13 +1,13 @@
-//===-- flang/unittests/Runtime/ListInputTest.cpp ---------------*- C++ -*-===//
+//===-- unittests/Runtime/ListInputTest.cpp ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
+#include "../../lib/Runtime/io-error.h"
 #include "CrashHandlerFixture.h"
-#include "../../runtime/io-error.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/io-api.h"
 

diff --git a/...g/unittests/Runtime/LogicalFormatTest.cpp → ...e/unittests/Runtime/LogicalFormatTest.cpp b/...g/unittests/Runtime/LogicalFormatTest.cpp → ...e/unittests/Runtime/LogicalFormatTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/LogicalFormatTest.cpp -----------*- C++ -*-===//
+//===-- unittests/Runtime/LogicalFormatTest.cpp -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/unittests/Runtime/Matmul.cpp → FortranRuntime/unittests/Runtime/Matmul.cpp b/flang/unittests/Runtime/Matmul.cpp → FortranRuntime/unittests/Runtime/Matmul.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Matmul.cpp--------- -------------*- C++ -*-===//
+//===-- unittests/Runtime/Matmul.cpp ----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,12 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/matmul.h"
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 using Fortran::common::TypeCategory;

diff --git a/flang/unittests/Runtime/MatmulTranspose.cpp → ...ime/unittests/Runtime/MatmulTranspose.cpp b/flang/unittests/Runtime/MatmulTranspose.cpp → ...ime/unittests/Runtime/MatmulTranspose.cpp
@@ -1,18 +1,18 @@
-//===-- flang/unittests/Runtime/MatmulTranspose.cpp -------------*- C++ -*-===//
+//===-- unittests/Runtime/MatmulTranspose.cpp -------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/matmul-transpose.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 using Fortran::common::TypeCategory;

diff --git a/flang/unittests/Runtime/MiscIntrinsic.cpp → ...ntime/unittests/Runtime/MiscIntrinsic.cpp b/flang/unittests/Runtime/MiscIntrinsic.cpp → ...ntime/unittests/Runtime/MiscIntrinsic.cpp
@@ -1,17 +1,17 @@
-//===-- flang/unittests/Runtime/MiscIntrinsic.cpp ---------------*- C++ -*-===//
+//===-- unittests/Runtime/MiscIntrinsic.cpp ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime//misc-intrinsic.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 

diff --git a/flang/unittests/Runtime/Namelist.cpp → ...ranRuntime/unittests/Runtime/Namelist.cpp b/flang/unittests/Runtime/Namelist.cpp → ...ranRuntime/unittests/Runtime/Namelist.cpp
@@ -1,16 +1,16 @@
-//===-- flang/unittests/Runtime/Namelist.cpp --------------------*- C++ -*-===//
+//===-- unittests/Runtime/Namelist.cpp --------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "../../runtime/namelist.h"
+#include "../../lib/Runtime/namelist.h"
 #include "CrashHandlerFixture.h"
-#include "tools.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/io-api.h"
+#include "tools.h"
 #include <algorithm>
 #include <cinttypes>
 #include <complex>

diff --git a/flang/unittests/Runtime/Numeric.cpp → FortranRuntime/unittests/Runtime/Numeric.cpp b/flang/unittests/Runtime/Numeric.cpp → FortranRuntime/unittests/Runtime/Numeric.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Numeric.cpp ---------------------*- C++ -*-===//
+//===-- unittests/Runtime/Numeric.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,8 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/numeric.h"
-#include "gtest/gtest.h"
 #include "flang/Common/float128.h"
+#include "gtest/gtest.h"
 #include <cmath>
 #include <limits>
 

diff --git a/...unittests/Runtime/NumericalFormatTest.cpp → ...unittests/Runtime/NumericalFormatTest.cpp b/...unittests/Runtime/NumericalFormatTest.cpp → ...unittests/Runtime/NumericalFormatTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/NumericalFormatTest.cpp ---------*- C++ -*-===//
+//===-- unittests/Runtime/NumericalFormatTest.cpp ---------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/unittests/Runtime/Pointer.cpp → FortranRuntime/unittests/Runtime/Pointer.cpp b/flang/unittests/Runtime/Pointer.cpp → FortranRuntime/unittests/Runtime/Pointer.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Pointer.cpp--------- -------------*- C++-*-===//
+//===-- unittests/Runtime/Pointer.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,9 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/pointer.h"
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/descriptor.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 

diff --git a/flang/unittests/Runtime/Ragged.cpp → FortranRuntime/unittests/Runtime/Ragged.cpp b/flang/unittests/Runtime/Ragged.cpp → FortranRuntime/unittests/Runtime/Ragged.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Ragged.cpp ----------------------*- C++ -*-===//
+//===-- unittests/Runtime/Ragged.cpp ----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/unittests/Runtime/Random.cpp → FortranRuntime/unittests/Runtime/Random.cpp b/flang/unittests/Runtime/Random.cpp → FortranRuntime/unittests/Runtime/Random.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Random.cpp ----------------------*- C++ -*-===//
+//===-- unittests/Runtime/Random.cpp ----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,9 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime//random.h"
-#include "gtest/gtest.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/type-code.h"
+#include "gtest/gtest.h"
 #include <cmath>
 
 using namespace Fortran::runtime;

diff --git a/flang/unittests/Runtime/Reduction.cpp → ...anRuntime/unittests/Runtime/Reduction.cpp b/flang/unittests/Runtime/Reduction.cpp → ...anRuntime/unittests/Runtime/Reduction.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Reductions.cpp ----------------------------===//
+//===-- unittests/Runtime/Reduction.cpp -------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,14 +7,14 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/reduction.h"
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Common/float128.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/reduce.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 #include <cstdint>
 #include <cstring>
 #include <string>

diff --git a/flang/unittests/Runtime/RuntimeCrashTest.cpp → ...me/unittests/Runtime/RuntimeCrashTest.cpp b/flang/unittests/Runtime/RuntimeCrashTest.cpp → ...me/unittests/Runtime/RuntimeCrashTest.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/CrashHandlerFixture.cpp ---------*- C++ -*-===//
+//===-- unittests/Runtime/RuntimeCrashTest.cpp ------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,11 +10,11 @@
 /// runtime components and ensure the test fixture handles crashes as we expect.
 //
 //===----------------------------------------------------------------------===//
+#include "../../lib/Runtime/terminator.h"
 #include "CrashHandlerFixture.h"
-#include "tools.h"
-#include "../../runtime/terminator.h"
 #include "flang/Runtime/io-api.h"
 #include "flang/Runtime/transformational.h"
+#include "tools.h"
 #include <gtest/gtest.h>
 
 using namespace Fortran::runtime;

diff --git a/flang/unittests/Runtime/Stop.cpp → FortranRuntime/unittests/Runtime/Stop.cpp b/flang/unittests/Runtime/Stop.cpp → FortranRuntime/unittests/Runtime/Stop.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Stop.cpp ----------------------------------===//
+//===-- unittests/Runtime/Stop.cpp ------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,8 +10,8 @@
 //
 //===----------------------------------------------------------------------===//
 #include "flang/Runtime/stop.h"
+#include "../../lib/Runtime/environment.h"
 #include "CrashHandlerFixture.h"
-#include "../../runtime/environment.h"
 #include <cstdlib>
 #include <gtest/gtest.h>
 

diff --git a/flang/unittests/Runtime/Support.cpp → FortranRuntime/unittests/Runtime/Support.cpp b/flang/unittests/Runtime/Support.cpp → FortranRuntime/unittests/Runtime/Support.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Support.cpp ----------------------*- C++-*-===//
+//===-- unittests/Runtime/Support.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,9 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/support.h"
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Runtime/descriptor.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 
 using namespace Fortran::runtime;
 using Fortran::common::TypeCategory;

diff --git a/flang/unittests/Runtime/TemporaryStack.cpp → ...time/unittests/Runtime/TemporaryStack.cpp b/flang/unittests/Runtime/TemporaryStack.cpp → ...time/unittests/Runtime/TemporaryStack.cpp
@@ -1,19 +1,19 @@
-//===--- flang/unittests/Runtime/TemporaryStack.cpp -------------*- C++ -*-===//
+//===-- unittests/Runtime/TemporaryStack.cpp --------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
-#include "tools.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/temporary-stack.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 #include <vector>
 
 using namespace Fortran::runtime;

diff --git a/flang/unittests/Runtime/Time.cpp → FortranRuntime/unittests/Runtime/Time.cpp b/flang/unittests/Runtime/Time.cpp → FortranRuntime/unittests/Runtime/Time.cpp
@@ -1,13 +1,13 @@
-//===-- flang/unittests/Runtime/Time.cpp ----------------------------===//
+//===-- unittests/Runtime/Time.cpp ------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "gtest/gtest.h"
 #include "flang/Runtime/time-intrinsic.h"
+#include "gtest/gtest.h"
 #include <algorithm>
 #include <cctype>
 #include <cerrno>

diff --git a/flang/unittests/Runtime/Transformational.cpp → ...me/unittests/Runtime/Transformational.cpp b/flang/unittests/Runtime/Transformational.cpp → ...me/unittests/Runtime/Transformational.cpp
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/Transformational.cpp ----------------------===//
+//===-- unittests/Runtime/Transformational.cpp ------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -7,10 +7,10 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Runtime/transformational.h"
-#include "gtest/gtest.h"
-#include "tools.h"
 #include "flang/Common/float128.h"
 #include "flang/Runtime/type-code.h"
+#include "tools.h"
+#include "gtest/gtest.h"
 #include <vector>
 
 using namespace Fortran::runtime;

diff --git a/flang/unittests/Runtime/tools.h → FortranRuntime/unittests/Runtime/tools.h b/flang/unittests/Runtime/tools.h → FortranRuntime/unittests/Runtime/tools.h
@@ -1,4 +1,4 @@
-//===-- flang/unittests/Runtime/tools.h -------------------------*- C++ -*-===//
+//===-- unittests/Runtime/tools.h -------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -9,11 +9,11 @@
 #ifndef FORTRAN_UNITTESTS_RUNTIME_TOOLS_H_
 #define FORTRAN_UNITTESTS_RUNTIME_TOOLS_H_
 
-#include "gtest/gtest.h"
 #include "flang/Runtime/allocatable.h"
 #include "flang/Runtime/cpp-type.h"
 #include "flang/Runtime/descriptor.h"
 #include "flang/Runtime/type-code.h"
+#include "gtest/gtest.h"
 #include <cstdint>
 #include <cstring>
 #include <vector>
@@ -54,4 +54,4 @@ static OwningPtr<Descriptor> MakeArray(const std::vector<int> &shape,
 }
 
 } // namespace Fortran::runtime
-#endif // FORTRAN_UNITTESTS_RUNTIME_TOOLS_H_
+#endif /* FORTRAN_UNITTESTS_RUNTIME_TOOLS_H_ */
diff --git a/flang/CMakeLists.txt b/flang/CMakeLists.txt
@@ -257,7 +257,8 @@ set(LLVM_BUILD_TOOLS ON)
 
 include_directories(BEFORE
   ${FLANG_BINARY_DIR}/include
-  ${FLANG_SOURCE_DIR}/include)
+  ${FLANG_SOURCE_DIR}/include
+  ${FLANG_SOURCE_DIR}/../FortranRuntime/include)
 
 # Add Flang-centric modules to cmake path.
 list(INSERT CMAKE_MODULE_PATH 0
@@ -468,7 +469,7 @@ if (FLANG_CUF_RUNTIME)
   find_package(CUDAToolkit REQUIRED)
 endif()
 
-add_subdirectory(runtime)
+add_subdirectory(../FortranRuntime/lib/Runtime runtime)
 
 if (LLVM_INCLUDE_EXAMPLES)
   add_subdirectory(examples)

diff --git a/flang/include/flang/Evaluate/call.h b/flang/include/flang/Evaluate/call.h
@@ -13,11 +13,11 @@
 #include "constant.h"
 #include "formatting.h"
 #include "type.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/indirection.h"
-#include "flang/Common/reference.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/attr.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
+#include "flang/Support/reference.h"
 #include <optional>
 #include <vector>
 

diff --git a/flang/include/flang/Evaluate/characteristics.h b/flang/include/flang/Evaluate/characteristics.h
@@ -18,13 +18,13 @@
 #include "shape.h"
 #include "tools.h"
 #include "type.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include <optional>
 #include <string>
 #include <variant>

diff --git a/flang/include/flang/Evaluate/common.h b/flang/include/flang/Evaluate/common.h
@@ -9,15 +9,16 @@
 #ifndef FORTRAN_EVALUATE_COMMON_H_
 #define FORTRAN_EVALUATE_COMMON_H_
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
 #include "flang/Common/restorer.h"
+#include "flang/Common/target-rounding.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/default-kinds.h"
+#include "flang/Support/indirection.h"
 #include <cinttypes>
 #include <map>
 #include <set>
@@ -32,6 +33,8 @@ class IntrinsicProcTable;
 class TargetCharacteristics;
 
 using common::ConstantSubscript;
+using common::RealFlag;
+using common::RealFlags;
 using common::RelationalOperator;
 
 // Integers are always ordered; reals may not be.
@@ -128,11 +131,6 @@ static constexpr bool Satisfies(RelationalOperator op, Relation relation) {
   return false; // silence g++ warning
 }
 
-// These are ordered like the bits in a common fenv.h header file.
-ENUM_CLASS(RealFlag, InvalidArgument, Denorm, DivideByZero, Overflow, Underflow,
-    Inexact)
-using RealFlags = common::EnumSet<RealFlag, RealFlag_enumSize>;
-
 template <typename A> struct ValueWithRealFlags {
   A AccumulateFlags(RealFlags &f) {
     f |= flags;

diff --git a/flang/include/flang/Evaluate/constant.h b/flang/include/flang/Evaluate/constant.h
@@ -11,8 +11,8 @@
 
 #include "formatting.h"
 #include "type.h"
-#include "flang/Common/default-kinds.h"
-#include "flang/Common/reference.h"
+#include "flang/Support/default-kinds.h"
+#include "flang/Support/reference.h"
 #include <map>
 #include <vector>
 

diff --git a/flang/include/flang/Evaluate/expression.h b/flang/include/flang/Evaluate/expression.h
@@ -21,11 +21,11 @@
 #include "formatting.h"
 #include "type.h"
 #include "variable.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
-#include "flang/Common/template.h"
 #include "flang/Parser/char-block.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
+#include "flang/Support/template.h"
 #include <algorithm>
 #include <list>
 #include <tuple>

diff --git a/flang/include/flang/Evaluate/formatting.h b/flang/include/flang/Evaluate/formatting.h
@@ -19,7 +19,7 @@
 // This header is meant to be included by the headers that define the several
 // representational class templates that need it, not by external clients.
 
-#include "flang/Common/indirection.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <optional>
 #include <type_traits>

diff --git a/flang/include/flang/Evaluate/intrinsics.h b/flang/include/flang/Evaluate/intrinsics.h
@@ -12,9 +12,9 @@
 #include "call.h"
 #include "characteristics.h"
 #include "type.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
+#include "flang/Support/default-kinds.h"
 #include <memory>
 #include <optional>
 #include <string>

diff --git a/flang/include/flang/Evaluate/shape.h b/flang/include/flang/Evaluate/shape.h
@@ -15,8 +15,8 @@
 #include "expression.h"
 #include "traverse.h"
 #include "variable.h"
-#include "flang/Common/indirection.h"
 #include "flang/Evaluate/type.h"
+#include "flang/Support/indirection.h"
 #include <optional>
 #include <variant>
 

diff --git a/flang/include/flang/Evaluate/target.h b/flang/include/flang/Evaluate/target.h
@@ -12,27 +12,16 @@
 #ifndef FORTRAN_EVALUATE_TARGET_H_
 #define FORTRAN_EVALUATE_TARGET_H_
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-class.h"
 #include "flang/Common/enum-set.h"
+#include "flang/Common/target-rounding.h"
 #include "flang/Evaluate/common.h"
+#include "flang/Support/Fortran.h"
 #include <cstdint>
 
 namespace Fortran::evaluate {
 
-// Floating-point rounding control
-struct Rounding {
-  common::RoundingMode mode{common::RoundingMode::TiesToEven};
-  // When set, emulate status flag behavior peculiar to x86
-  // (viz., fail to set the Underflow flag when an inexact product of a
-  // multiplication is rounded up to a normal number from a subnormal
-  // in some rounding modes)
-#if __x86_64__ || __riscv || __loongarch__
-  bool x86CompatibleBehavior{true};
-#else
-  bool x86CompatibleBehavior{false};
-#endif
-};
+using common::Rounding;
 
 ENUM_CLASS(IeeeFeature, Denormal, Divide, Flags, Halting, Inf, Io, NaN,
     Rounding, Sqrt, Standard, Subnormal, UnderflowControl)

diff --git a/flang/include/flang/Evaluate/tools.h b/flang/include/flang/Evaluate/tools.h
@@ -11,8 +11,6 @@
 
 #include "traverse.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/template.h"
-#include "flang/Common/unwrap.h"
 #include "flang/Evaluate/constant.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/shape.h"
@@ -21,6 +19,8 @@
 #include "flang/Semantics/attr.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/template.h"
+#include "flang/Support/unwrap.h"
 #include <array>
 #include <optional>
 #include <set>

diff --git a/flang/include/flang/Evaluate/traverse.h b/flang/include/flang/Evaluate/traverse.h
@@ -38,9 +38,9 @@
 // expression of an ASSOCIATE (or related) construct entity.
 
 #include "expression.h"
-#include "flang/Common/indirection.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/indirection.h"
 #include <set>
 #include <type_traits>
 

diff --git a/flang/include/flang/Evaluate/type.h b/flang/include/flang/Evaluate/type.h
@@ -22,11 +22,11 @@
 #include "integer.h"
 #include "logical.h"
 #include "real.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/real.h"
-#include "flang/Common/template.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/template.h"
 #include <cinttypes>
 #include <optional>
 #include <string>

diff --git a/flang/include/flang/Evaluate/variable.h b/flang/include/flang/Evaluate/variable.h
@@ -21,9 +21,9 @@
 #include "static-data.h"
 #include "type.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/reference.h"
-#include "flang/Common/template.h"
 #include "flang/Parser/char-block.h"
+#include "flang/Support/reference.h"
+#include "flang/Support/template.h"
 #include <optional>
 #include <variant>
 #include <vector>

diff --git a/flang/include/flang/Frontend/FrontendOptions.h b/flang/include/flang/Frontend/FrontendOptions.h
@@ -13,10 +13,10 @@
 #ifndef FORTRAN_FRONTEND_FRONTENDOPTIONS_H
 #define FORTRAN_FRONTEND_FRONTENDOPTIONS_H
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Lower/EnvironmentDefault.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/unparse.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <cstdint>

diff --git a/flang/include/flang/ISO_Fortran_binding.h b/flang/include/flang/ISO_Fortran_binding.h
@@ -1,20 +1,19 @@
-/*===-- include/flang/ISO_Fortran_binding.h -----------------------*- C++ -*-===
+/*===-- include/flang/Common/ISO_Fortran_binding.h ------------------*- C -*-===
  *
  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  * See https://llvm.org/LICENSE.txt for license information.
  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  *
- * ===-----------------------------------------------------------------------===
- */
+ *===----------------------------------------------------------------------===*/
 
-#ifndef CFI_ISO_FORTRAN_BINDING_H_
-#define CFI_ISO_FORTRAN_BINDING_H_
+#ifndef FORTRAN_COMMON_ISO_FORTRAN_BINDING_H_
+#define FORTRAN_COMMON_ISO_FORTRAN_BINDING_H_
 
 /* When this header is included into the compiler and runtime implementations,
  * it does so by means of a wrapper header that establishes namespaces and
  * a macro for extra function attributes (RT_API_ATTRS).
  */
-#ifndef FORTRAN_ISO_FORTRAN_BINDING_WRAPPER_H_
+#ifndef FORTRAN_COMMON_ISO_FORTRAN_BINDING_WRAPPER_H_
 #include <stddef.h>
 #define FORTRAN_ISO_NAMESPACE_
 #endif
@@ -207,4 +206,4 @@ RT_API_ATTRS int CFI_setpointer(
 } // extern "C"
 #endif
 
-#endif /* CFI_ISO_FORTRAN_BINDING_H_ */
+#endif /* FORTRAN_COMMON_ISO_FORTRAN_BINDING_H_ */
diff --git a/flang/include/flang/Lower/AbstractConverter.h b/flang/include/flang/Lower/AbstractConverter.h
@@ -13,12 +13,12 @@
 #ifndef FORTRAN_LOWER_ABSTRACTCONVERTER_H
 #define FORTRAN_LOWER_ABSTRACTCONVERTER_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Lower/PFTDefs.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Dialect/FIRAttr.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/Operation.h"

diff --git a/flang/include/flang/Lower/Bridge.h b/flang/include/flang/Lower/Bridge.h
@@ -13,13 +13,13 @@
 #ifndef FORTRAN_LOWER_BRIDGE_H
 #define FORTRAN_LOWER_BRIDGE_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Lower/AbstractConverter.h"
 #include "flang/Lower/EnvironmentDefault.h"
 #include "flang/Lower/LoweringOptions.h"
 #include "flang/Lower/StatementContext.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinOps.h"
 #include <set>
 

diff --git a/flang/include/flang/Lower/CallInterface.h b/flang/include/flang/Lower/CallInterface.h
@@ -27,8 +27,8 @@
 #ifndef FORTRAN_LOWER_CALLINTERFACE_H
 #define FORTRAN_LOWER_CALLINTERFACE_H
 
-#include "flang/Common/reference.h"
 #include "flang/Evaluate/characteristics.h"
+#include "flang/Support/reference.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/IR/BuiltinOps.h"
 #include <memory>

diff --git a/flang/include/flang/Lower/ConvertType.h b/flang/include/flang/Lower/ConvertType.h
@@ -21,8 +21,8 @@
 #ifndef FORTRAN_LOWER_CONVERT_TYPE_H
 #define FORTRAN_LOWER_CONVERT_TYPE_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/type.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinTypes.h"
 
 namespace mlir {

diff --git a/flang/include/flang/Lower/LoweringOptions.h b/flang/include/flang/Lower/LoweringOptions.h
@@ -15,7 +15,7 @@
 #ifndef FLANG_LOWER_LOWERINGOPTIONS_H
 #define FLANG_LOWER_LOWERINGOPTIONS_H
 
-#include "flang/Common/MathOptionsBase.h"
+#include "flang/Support/MathOptionsBase.h"
 
 namespace Fortran::lower {
 

diff --git a/flang/include/flang/Lower/PFTBuilder.h b/flang/include/flang/Lower/PFTBuilder.h
@@ -17,15 +17,15 @@
 #ifndef FORTRAN_LOWER_PFTBUILDER_H
 #define FORTRAN_LOWER_PFTBUILDER_H
 
-#include "flang/Common/reference.h"
-#include "flang/Common/template.h"
 #include "flang/Lower/HostAssociations.h"
 #include "flang/Lower/PFTDefs.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/attr.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/reference.h"
+#include "flang/Support/template.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 

diff --git a/flang/include/flang/Lower/Support/Utils.h b/flang/include/flang/Lower/Support/Utils.h
@@ -13,9 +13,9 @@
 #ifndef FORTRAN_LOWER_SUPPORT_UTILS_H
 #define FORTRAN_LOWER_SUPPORT_UTILS_H
 
-#include "flang/Common/indirection.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/indirection.h"
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/IR/BuiltinAttributes.h"

diff --git a/flang/include/flang/Lower/SymbolMap.h b/flang/include/flang/Lower/SymbolMap.h
@@ -13,12 +13,12 @@
 #ifndef FORTRAN_LOWER_SYMBOLMAP_H
 #define FORTRAN_LOWER_SYMBOLMAP_H
 
-#include "flang/Common/reference.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Dialect/FortranVariableInterface.h"
 #include "flang/Optimizer/Support/Matcher.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/reference.h"
 #include "mlir/IR/Value.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"

diff --git a/flang/include/flang/Optimizer/Builder/FIRBuilder.h b/flang/include/flang/Optimizer/Builder/FIRBuilder.h
@@ -16,12 +16,12 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
 
-#include "flang/Common/MathOptionsBase.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
+#include "flang/Support/MathOptionsBase.h"
 #include "mlir/IR/Builders.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "llvm/ADT/DenseMap.h"

diff --git a/flang/include/flang/Optimizer/Builder/IntrinsicCall.h b/flang/include/flang/Optimizer/Builder/IntrinsicCall.h
@@ -397,6 +397,7 @@ struct IntrinsicLibrary {
   fir::ExtendedValue genUbound(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genUnpack(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genVerify(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
+    fir::ExtendedValue genNumericStorageSize(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
 
   /// Implement all conversion functions like DBLE, the first argument is
   /// the value to convert. There may be an additional KIND arguments that

diff --git a/flang/include/flang/Optimizer/Builder/PPCIntrinsicCall.h b/flang/include/flang/Optimizer/Builder/PPCIntrinsicCall.h
@@ -9,8 +9,8 @@
 #ifndef FORTRAN_LOWER_PPCINTRINSICCALL_H
 #define FORTRAN_LOWER_PPCINTRINSICCALL_H
 
-#include "flang/Common/static-multimap-view.h"
 #include "flang/Optimizer/Builder/IntrinsicCall.h"
+#include "flang/Support/static-multimap-view.h"
 #include "mlir/Dialect/Math/IR/Math.h"
 
 namespace fir {

diff --git a/flang/include/flang/Optimizer/Builder/Runtime/RTBuilder.h b/flang/include/flang/Optimizer/Builder/Runtime/RTBuilder.h
@@ -17,12 +17,12 @@
 #ifndef FORTRAN_OPTIMIZER_BUILDER_RUNTIME_RTBUILDER_H
 #define FORTRAN_OPTIMIZER_BUILDER_RUNTIME_RTBUILDER_H
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/uint128.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Runtime/reduce.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinTypes.h"
 #include "mlir/IR/MLIRContext.h"
 #include "llvm/ADT/SmallVector.h"

diff --git a/flang/include/flang/Optimizer/CodeGen/DescriptorModel.h b/flang/include/flang/Optimizer/CodeGen/DescriptorModel.h
@@ -22,7 +22,7 @@
 #ifndef OPTIMIZER_DESCRIPTOR_MODEL_H
 #define OPTIMIZER_DESCRIPTOR_MODEL_H
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Runtime/descriptor.h"
 #include "mlir/Dialect/LLVMIR/LLVMTypes.h"
 #include "mlir/IR/BuiltinTypes.h"

diff --git a/flang/include/flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h b/flang/include/flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h
@@ -13,7 +13,7 @@
 #ifndef FORTRAN_OPTIMIZER_DIALECT_CUF_CUFATTR_H
 #define FORTRAN_OPTIMIZER_DIALECT_CUF_CUFATTR_H
 
-#include "flang/Common/Fortran.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/BuiltinAttributes.h"
 
 namespace llvm {

diff --git a/flang/include/flang/Optimizer/Support/TypeCode.h b/flang/include/flang/Optimizer/Support/TypeCode.h
@@ -13,7 +13,7 @@
 #ifndef FORTRAN_OPTIMIZER_SUPPORT_TYPECODE_H
 #define FORTRAN_OPTIMIZER_SUPPORT_TYPECODE_H
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "llvm/Support/ErrorHandling.h"
 
 namespace fir {

diff --git a/flang/include/flang/Optimizer/Support/Utils.h b/flang/include/flang/Optimizer/Support/Utils.h
@@ -13,13 +13,13 @@
 #ifndef FORTRAN_OPTIMIZER_SUPPORT_UTILS_H
 #define FORTRAN_OPTIMIZER_SUPPORT_UTILS_H
 
-#include "flang/Common/default-kinds.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/CUF/Attributes/CUFAttr.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Support/FatalError.h"
+#include "flang/Support/default-kinds.h"
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/IR/BuiltinAttributes.h"

diff --git a/flang/include/flang/Parser/char-block.h b/flang/include/flang/Parser/char-block.h
@@ -11,7 +11,7 @@
 
 // Describes a contiguous block of characters; does not own their storage.
 
-#include "flang/Common/interval.h"
+#include "flang/Support/interval.h"
 #include <algorithm>
 #include <cstddef>
 #include <cstring>

diff --git a/flang/include/flang/Parser/dump-parse-tree.h b/flang/include/flang/Parser/dump-parse-tree.h
@@ -14,9 +14,9 @@
 #include "parse-tree.h"
 #include "tools.h"
 #include "unparse.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <string>
 #include <type_traits>

diff --git a/flang/include/flang/Parser/message.h b/flang/include/flang/Parser/message.h
@@ -16,8 +16,8 @@
 #include "char-set.h"
 #include "provenance.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/reference-counted.h"
 #include "flang/Common/restorer.h"
+#include "flang/Support/reference-counted.h"
 #include <cstddef>
 #include <cstring>
 #include <forward_list>

diff --git a/flang/include/flang/Parser/parse-state.h b/flang/include/flang/Parser/parse-state.h
@@ -16,11 +16,11 @@
 // and recovery during parsing!
 
 #include "user-state.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/provenance.h"
+#include "flang/Support/Fortran-features.h"
 #include <cstddef>
 #include <cstring>
 #include <list>

diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
@@ -22,9 +22,9 @@
 #include "format-specification.h"
 #include "message.h"
 #include "provenance.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Frontend/OpenACC/ACC.h.inc"
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
 #include <cinttypes>

diff --git a/flang/include/flang/Parser/parsing.h b/flang/include/flang/Parser/parsing.h
@@ -14,8 +14,8 @@
 #include "message.h"
 #include "parse-tree.h"
 #include "provenance.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Parser/preprocessor.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/Support/raw_ostream.h"
 #include <optional>
 #include <string>

diff --git a/flang/include/flang/Parser/provenance.h b/flang/include/flang/Parser/provenance.h
@@ -14,7 +14,7 @@
 #include "characters.h"
 #include "source.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/interval.h"
+#include "flang/Support/interval.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstddef>
 #include <list>

diff --git a/flang/include/flang/Parser/source.h b/flang/include/flang/Parser/source.h
@@ -15,7 +15,7 @@
 //  - A Unicode byte order mark is recognized if present.
 
 #include "characters.h"
-#include "flang/Common/reference.h"
+#include "flang/Support/reference.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstddef>

diff --git a/flang/include/flang/Parser/user-state.h b/flang/include/flang/Parser/user-state.h
@@ -14,10 +14,10 @@
 // parse tree construction so as to avoid any need for representing
 // state in static data.
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/parse-tree.h"
+#include "flang/Support/Fortran-features.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cinttypes>
 #include <optional>

diff --git a/flang/include/flang/Semantics/expression.h b/flang/include/flang/Semantics/expression.h
@@ -10,8 +10,6 @@
 #define FORTRAN_SEMANTICS_EXPRESSION_H_
 
 #include "semantics.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/indirection.h"
 #include "flang/Common/restorer.h"
 #include "flang/Common/visit.h"
 #include "flang/Evaluate/characteristics.h"
@@ -24,6 +22,8 @@
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include <map>
 #include <optional>
 #include <type_traits>

diff --git a/flang/include/flang/Semantics/runtime-type-info.h b/flang/include/flang/Semantics/runtime-type-info.h
@@ -14,8 +14,8 @@
 #ifndef FORTRAN_SEMANTICS_RUNTIME_TYPE_INFO_H_
 #define FORTRAN_SEMANTICS_RUNTIME_TYPE_INFO_H_
 
-#include "flang/Common/reference.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/reference.h"
 #include <map>
 #include <set>
 #include <string>

diff --git a/flang/include/flang/Semantics/scope.h b/flang/include/flang/Semantics/scope.h
@@ -11,11 +11,11 @@
 
 #include "attr.h"
 #include "symbol.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/reference.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/provenance.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/reference.h"
 #include <list>
 #include <map>
 #include <optional>

diff --git a/flang/include/flang/Semantics/semantics.h b/flang/include/flang/Semantics/semantics.h
@@ -11,12 +11,12 @@
 
 #include "scope.h"
 #include "symbol.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Evaluate/common.h"
 #include "flang/Evaluate/intrinsics.h"
 #include "flang/Evaluate/target.h"
 #include "flang/Parser/message.h"
 #include "flang/Semantics/module-dependences.h"
+#include "flang/Support/Fortran-features.h"
 #include <iosfwd>
 #include <set>
 #include <string>

diff --git a/flang/include/flang/Semantics/symbol.h b/flang/include/flang/Semantics/symbol.h
@@ -10,11 +10,11 @@
 #define FORTRAN_SEMANTICS_SYMBOL_H_
 
 #include "type.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
-#include "flang/Common/reference.h"
 #include "flang/Common/visit.h"
 #include "flang/Semantics/module-dependences.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/reference.h"
 #include "llvm/ADT/DenseMapInfo.h"
 
 #include <array>

diff --git a/flang/include/flang/Semantics/tools.h b/flang/include/flang/Semantics/tools.h
@@ -12,7 +12,6 @@
 // Simple predicates and look-up functions that are best defined
 // canonically for use in semantic checking.
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/visit.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/shape.h"
@@ -23,6 +22,7 @@
 #include "flang/Semantics/attr.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/Fortran.h"
 #include <functional>
 
 namespace Fortran::semantics {

diff --git a/flang/include/flang/Semantics/type.h b/flang/include/flang/Semantics/type.h
@@ -9,10 +9,10 @@
 #ifndef FORTRAN_SEMANTICS_TYPE_H_
 #define FORTRAN_SEMANTICS_TYPE_H_
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Parser/char-block.h"
+#include "flang/Support/Fortran.h"
 #include <algorithm>
 #include <iosfwd>
 #include <map>

diff --git a/...g/include/flang/Common/Fortran-features.h → .../include/flang/Support/Fortran-features.h b/...g/include/flang/Common/Fortran-features.h → .../include/flang/Support/Fortran-features.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/Fortran-features.h -----------------*- C++ -*-===//
+//===-- include/flang/Support/Fortran-features.h ----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -9,9 +9,9 @@
 #ifndef FORTRAN_COMMON_FORTRAN_FEATURES_H_
 #define FORTRAN_COMMON_FORTRAN_FEATURES_H_
 
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
+#include "flang/Support/Fortran.h"
 #include <vector>
 
 namespace Fortran::common {

diff --git a/flang/include/flang/Common/Fortran.h → flang/include/flang/Support/Fortran.h b/flang/include/flang/Common/Fortran.h → flang/include/flang/Support/Fortran.h
@@ -12,19 +12,16 @@
 // Fortran language concepts that are used in many phases are defined
 // once here to avoid redundancy and needless translation.
 
-#include "enum-set.h"
-#include "idioms.h"
+#include "flang/Common/Fortran-consts.h"
+#include "flang/Common/enum-set.h"
+#include "flang/Common/idioms.h"
 #include <cinttypes>
 #include <optional>
 #include <string>
 
 namespace Fortran::common {
 class LanguageFeatureControl;
 
-// Fortran has five kinds of intrinsic data types, plus the derived types.
-ENUM_CLASS(TypeCategory, Integer, Real, Complex, Character, Logical, Derived)
-ENUM_CLASS(VectorElementCategory, Integer, Unsigned, Real)
-
 constexpr bool IsNumericTypeCategory(TypeCategory category) {
   return category == TypeCategory::Integer || category == TypeCategory::Real ||
       category == TypeCategory::Complex;
@@ -47,9 +44,6 @@ const char *AsFortran(RelationalOperator);
 
 ENUM_CLASS(Intent, Default, In, Out, InOut)
 
-ENUM_CLASS(IoStmtKind, None, Backspace, Close, Endfile, Flush, Inquire, Open,
-    Print, Read, Rewind, Wait, Write)
-
 // Union of specifiers for all I/O statements.
 ENUM_CLASS(IoSpecKind, Access, Action, Advance, Asynchronous, Blank, Decimal,
     Delim, Direct, Encoding, End, Eor, Err, Exist, File, Fmt, Form, Formatted,
@@ -61,29 +55,11 @@ ENUM_CLASS(IoSpecKind, Access, Action, Advance, Asynchronous, Blank, Decimal,
     Dispose, // nonstandard
 )
 
-// Defined I/O variants
-ENUM_CLASS(
-    DefinedIo, ReadFormatted, ReadUnformatted, WriteFormatted, WriteUnformatted)
 const char *AsFortran(DefinedIo);
 
-// Floating-point rounding modes; these are packed into a byte to save
-// room in the runtime's format processing context structure.  These
-// enumerators are defined with the corresponding values returned from
-// llvm.get.rounding.
-enum class RoundingMode : std::uint8_t {
-  ToZero, // ROUND=ZERO, RZ - truncation
-  TiesToEven, // ROUND=NEAREST, RN - default IEEE rounding
-  Up, // ROUND=UP, RU
-  Down, // ROUND=DOWN, RD
-  TiesAwayFromZero, // ROUND=COMPATIBLE, RC - ties round away from zero
-};
-
 // Fortran label. Must be in [1..99999].
 using Label = std::uint64_t;
 
-// Fortran arrays may have up to 15 dimensions (See Fortran 2018 section 5.4.6).
-static constexpr int maxRank{15};
-
 // CUDA subprogram attribute combinations
 ENUM_CLASS(CUDASubprogramAttrs, Host, Device, HostDevice, Global, Grid_Global)
 

diff --git a/.../include/flang/Common/MathOptionsBase.def → ...include/flang/Support/MathOptionsBase.def b/.../include/flang/Common/MathOptionsBase.def → ...include/flang/Support/MathOptionsBase.def
diff --git a/flang/include/flang/Common/MathOptionsBase.h → ...g/include/flang/Support/MathOptionsBase.h b/flang/include/flang/Common/MathOptionsBase.h → ...g/include/flang/Support/MathOptionsBase.h
@@ -1,4 +1,4 @@
-//===- MathOptionsBase.h - Math options config ------------------*- C++ -*-===//
+//===-- include/flang/Support/MathOptionsBase.h -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -27,16 +27,16 @@ class MathOptionsBase {
     Name = static_cast<unsigned>(Value); \
     return *this; \
   }
-#include "flang/Common/MathOptionsBase.def"
+#include "flang/Support/MathOptionsBase.def"
 
   MathOptionsBase() {
 #define ENUM_MATHOPT(Name, Type, Bits, Default) set##Name(Default);
-#include "flang/Common/MathOptionsBase.def"
+#include "flang/Support/MathOptionsBase.def"
   }
 
 private:
 #define ENUM_MATHOPT(Name, Type, Bits, Default) unsigned Name : Bits;
-#include "flang/Common/MathOptionsBase.def"
+#include "flang/Support/MathOptionsBase.def"
 };
 
 } // namespace Fortran::common

diff --git a/flang/include/flang/Common/OpenMP-features.h → ...g/include/flang/Support/OpenMP-features.h b/flang/include/flang/Common/OpenMP-features.h → ...g/include/flang/Support/OpenMP-features.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/OpenMP-features.h -----------------*- C++ -*-====//
+//===-- include/flang/Support/OpenMP-features.h -----------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/include/flang/Common/Version.h → flang/include/flang/Support/Version.h b/flang/include/flang/Common/Version.h → flang/include/flang/Support/Version.h
@@ -1,4 +1,4 @@
-//===- Version.h - Flang Version Number ---------------------*- Fortran -*-===//
+//===-- include/flang/Support/Version.h -------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/include/flang/Common/default-kinds.h → flang/include/flang/Support/default-kinds.h b/flang/include/flang/Common/default-kinds.h → flang/include/flang/Support/default-kinds.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/default-kinds.h --------------------*- C++ -*-===//
+//===-- include/flang/Support/default-kinds.h -------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -9,7 +9,7 @@
 #ifndef FORTRAN_COMMON_DEFAULT_KINDS_H_
 #define FORTRAN_COMMON_DEFAULT_KINDS_H_
 
-#include "flang/Common/Fortran.h"
+#include "flang/Support/Fortran.h"
 #include <cstdint>
 
 namespace Fortran::common {

diff --git a/flang/include/flang/Common/indirection.h → flang/include/flang/Support/indirection.h b/flang/include/flang/Common/indirection.h → flang/include/flang/Support/indirection.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/indirection.h ----------------------*- C++ -*-===//
+//===-- include/flang/Support/indirection.h ---------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -20,7 +20,7 @@
 //    template class Fortran::common::Indirection<FORWARD_TYPE>;
 // in one C++ source file later where a definition of the type is visible.
 
-#include "idioms.h"
+#include "flang/Common/idioms.h"
 #include <memory>
 #include <type_traits>
 #include <utility>

diff --git a/flang/include/flang/Common/interval.h → flang/include/flang/Support/interval.h b/flang/include/flang/Common/interval.h → flang/include/flang/Support/interval.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/interval.h -------------------------*- C++ -*-===//
+//===-- include/flang/Support/interval.h ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -12,7 +12,7 @@
 // Defines a generalized template class Interval<A> to represent
 // the half-open interval [x .. x+n).
 
-#include "idioms.h"
+#include "flang/Common/idioms.h"
 #include <algorithm>
 #include <cstddef>
 #include <utility>

diff --git a/.../include/flang/Common/reference-counted.h → ...include/flang/Support/reference-counted.h b/.../include/flang/Common/reference-counted.h → ...include/flang/Support/reference-counted.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/reference-counted.h ----------------*- C++ -*-===//
+//===-- include/flang/Support/reference-counted.h ---------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/include/flang/Common/reference.h → flang/include/flang/Support/reference.h b/flang/include/flang/Common/reference.h → flang/include/flang/Support/reference.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/reference.h ------------------------*- C++ -*-===//
+//===-- include/flang/Support/reference.h -----------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/...clude/flang/Common/static-multimap-view.h → ...lude/flang/Support/static-multimap-view.h b/...clude/flang/Common/static-multimap-view.h → ...lude/flang/Support/static-multimap-view.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/static-multimap-view.h -------------*- C++ -*-===//
+//===-- include/flang/Support/static-multimap-view.h ------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/include/flang/Common/template.h → flang/include/flang/Support/template.h b/flang/include/flang/Common/template.h → flang/include/flang/Support/template.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/template.h -------------------------*- C++ -*-===//
+//===-- include/flang/Support/template.h ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -9,8 +9,8 @@
 #ifndef FORTRAN_COMMON_TEMPLATE_H_
 #define FORTRAN_COMMON_TEMPLATE_H_
 
-#include "variant.h"
 #include "flang/Common/idioms.h"
+#include "flang/Common/variant.h"
 #include <functional>
 #include <optional>
 #include <tuple>

diff --git a/flang/include/flang/Common/unwrap.h → flang/include/flang/Support/unwrap.h b/flang/include/flang/Common/unwrap.h → flang/include/flang/Support/unwrap.h
@@ -1,4 +1,4 @@
-//===-- include/flang/Common/unwrap.h ---------------------------*- C++ -*-===//
+//===-- include/flang/Support/unwrap.h --------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -12,8 +12,8 @@
 #include "indirection.h"
 #include "reference-counted.h"
 #include "reference.h"
-#include "variant.h"
-#include "visit.h"
+#include "flang/Common/variant.h"
+#include "flang/Common/visit.h"
 #include <memory>
 #include <optional>
 #include <type_traits>

diff --git a/flang/include/flang/Tools/CrossToolHelpers.h b/flang/include/flang/Tools/CrossToolHelpers.h
@@ -13,9 +13,9 @@
 #ifndef FORTRAN_TOOLS_CROSS_TOOL_HELPERS_H
 #define FORTRAN_TOOLS_CROSS_TOOL_HELPERS_H
 
-#include "flang/Common/MathOptionsBase.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/LangOptions.h"
+#include "flang/Support/MathOptionsBase.h"
 #include <cstdint>
 
 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"

diff --git a/flang/lib/Common/CMakeLists.txt b/flang/lib/Common/CMakeLists.txt
@@ -36,11 +36,11 @@ endif()
 
 
 add_flang_library(FortranCommon
-  Fortran.cpp
-  Fortran-features.cpp
-  default-kinds.cpp
-  idioms.cpp
-  Version.cpp
+  ../Support/Fortran.cpp
+  ../Support/Fortran-features.cpp
+  ../Support/default-kinds.cpp
+  ../Support/idioms.cpp
+  ../Support/Version.cpp
   ${version_inc}
 
   LINK_COMPONENTS

diff --git a/flang/lib/Decimal/CMakeLists.txt b/flang/lib/Decimal/CMakeLists.txt
@@ -37,7 +37,8 @@ if (CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
     add_compile_definitions(FLANG_LITTLE_ENDIAN=1)
   endif ()
   include_directories(BEFORE
-    ${FLANG_SOURCE_DIR}/include)
+    ${FLANG_SOURCE_DIR}/include
+    ${FLANG_SOURCE_DIR}/../FortranRuntime/include)
 endif()
 
 check_cxx_compiler_flag(-fno-lto FLANG_RUNTIME_HAS_FNO_LTO_FLAG)
@@ -50,8 +51,8 @@ endif()
 add_definitions(-U_GLIBCXX_ASSERTIONS)
 
 set(sources
-  binary-to-decimal.cpp
-  decimal-to-binary.cpp
+  ../../../FortranRuntime/lib/Common/binary-to-decimal.cpp
+  ../../../FortranRuntime/lib/Common/decimal-to-binary.cpp
 )
 
 include(AddFlangOffloadRuntime)
@@ -63,23 +64,23 @@ add_flang_library(FortranDecimal INSTALL_WITH_TOOLCHAIN ${sources})
 if (DEFINED MSVC)
   set(CMAKE_MSVC_RUNTIME_LIBRARY MultiThreaded)
   add_flang_library(FortranDecimal.static INSTALL_WITH_TOOLCHAIN
-          binary-to-decimal.cpp
-          decimal-to-binary.cpp
+          ../../../FortranRuntime/lib/Common/binary-to-decimal.cpp
+          ../../../FortranRuntime/lib/Common/decimal-to-binary.cpp
   )
   set(CMAKE_MSVC_RUNTIME_LIBRARY MultiThreadedDLL)
   add_flang_library(FortranDecimal.dynamic INSTALL_WITH_TOOLCHAIN
-    binary-to-decimal.cpp
-    decimal-to-binary.cpp
+    ../../../FortranRuntime/lib/Common/binary-to-decimal.cpp
+    ../../../FortranRuntime/lib/Common/decimal-to-binary.cpp
   )
   set(CMAKE_MSVC_RUNTIME_LIBRARY MultiThreadedDebug)
   add_flang_library(FortranDecimal.static_dbg INSTALL_WITH_TOOLCHAIN
-          binary-to-decimal.cpp
-          decimal-to-binary.cpp
+          ../../../FortranRuntime/lib/Common/binary-to-decimal.cpp
+          ../../../FortranRuntime/lib/Common/decimal-to-binary.cpp
   )
   set(CMAKE_MSVC_RUNTIME_LIBRARY MultiThreadedDebugDLL)
   add_flang_library(FortranDecimal.dynamic_dbg INSTALL_WITH_TOOLCHAIN
-    binary-to-decimal.cpp
-    decimal-to-binary.cpp
+    ../../../FortranRuntime/lib/Common/binary-to-decimal.cpp
+    ../../../FortranRuntime/lib/Common/decimal-to-binary.cpp
   )
   add_dependencies(FortranDecimal FortranDecimal.static FortranDecimal.dynamic
     FortranDecimal.static_dbg FortranDecimal.dynamic_dbg)

diff --git a/flang/lib/Evaluate/call.cpp b/flang/lib/Evaluate/call.cpp
@@ -7,13 +7,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/call.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/characteristics.h"
 #include "flang/Evaluate/check-expression.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/tools.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 
 namespace Fortran::evaluate {
 

diff --git a/flang/lib/Evaluate/characteristics.cpp b/flang/lib/Evaluate/characteristics.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/characteristics.h"
-#include "flang/Common/indirection.h"
 #include "flang/Evaluate/check-expression.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/intrinsics.h"
@@ -17,6 +16,7 @@
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <initializer_list>
 

diff --git a/flang/lib/Evaluate/common.cpp b/flang/lib/Evaluate/common.cpp
@@ -11,8 +11,11 @@
 
 using namespace Fortran::parser::literals;
 
+
+
 namespace Fortran::evaluate {
 
+
 void RealFlagWarnings(
     FoldingContext &context, const RealFlags &flags, const char *operation) {
   if (context.languageFeatures().ShouldWarn(

diff --git a/flang/lib/Evaluate/fold-implementation.h b/flang/lib/Evaluate/fold-implementation.h
@@ -12,9 +12,6 @@
 #include "character.h"
 #include "host.h"
 #include "int-power.h"
-#include "flang/Common/indirection.h"
-#include "flang/Common/template.h"
-#include "flang/Common/unwrap.h"
 #include "flang/Evaluate/characteristics.h"
 #include "flang/Evaluate/common.h"
 #include "flang/Evaluate/constant.h"
@@ -31,6 +28,9 @@
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/indirection.h"
+#include "flang/Support/template.h"
+#include "flang/Support/unwrap.h"
 #include <algorithm>
 #include <cmath>
 #include <complex>

diff --git a/flang/lib/Evaluate/fold-logical.cpp b/flang/lib/Evaluate/fold-logical.cpp
@@ -9,8 +9,8 @@
 #include "fold-implementation.h"
 #include "fold-matmul.h"
 #include "fold-reduction.h"
+#include "flang/Common/magic-numbers.h"
 #include "flang/Evaluate/check-expression.h"
-#include "flang/Runtime/magic-numbers.h"
 
 namespace Fortran::evaluate {
 

diff --git a/flang/lib/Evaluate/formatting.cpp b/flang/lib/Evaluate/formatting.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/formatting.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/call.h"
 #include "flang/Evaluate/constant.h"
 #include "flang/Evaluate/expression.h"
@@ -16,6 +15,7 @@
 #include "flang/Parser/characters.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace Fortran::evaluate {

diff --git a/flang/lib/Evaluate/intrinsics-library.cpp b/flang/lib/Evaluate/intrinsics-library.cpp
@@ -14,8 +14,8 @@
 #include "flang/Evaluate/intrinsics-library.h"
 #include "fold-implementation.h"
 #include "host.h"
-#include "flang/Common/static-multimap-view.h"
 #include "flang/Evaluate/expression.h"
+#include "flang/Support/static-multimap-view.h"
 #include <cfloat>
 #include <cmath>
 #include <complex>

diff --git a/flang/lib/Evaluate/intrinsics.cpp b/flang/lib/Evaluate/intrinsics.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/intrinsics.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/enum-set.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/check-expression.h"
@@ -19,6 +18,7 @@
 #include "flang/Evaluate/type.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cmath>

diff --git a/flang/lib/Evaluate/real.cpp b/flang/lib/Evaluate/real.cpp
@@ -8,8 +8,8 @@
 
 #include "flang/Evaluate/real.h"
 #include "int-power.h"
+#include "flang/Common/decimal.h"
 #include "flang/Common/idioms.h"
-#include "flang/Decimal/decimal.h"
 #include "flang/Parser/characters.h"
 #include "llvm/Support/raw_ostream.h"
 #include <limits>

diff --git a/flang/lib/Evaluate/shape.cpp b/flang/lib/Evaluate/shape.cpp
@@ -8,7 +8,6 @@
 
 #include "flang/Evaluate/shape.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/template.h"
 #include "flang/Evaluate/characteristics.h"
 #include "flang/Evaluate/check-expression.h"
 #include "flang/Evaluate/fold.h"
@@ -17,6 +16,7 @@
 #include "flang/Evaluate/type.h"
 #include "flang/Parser/message.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/template.h"
 #include <functional>
 
 using namespace std::placeholders; // _1, _2, &c. for std::bind()

diff --git a/flang/lib/Evaluate/target.cpp b/flang/lib/Evaluate/target.cpp
@@ -7,9 +7,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Evaluate/target.h"
-#include "flang/Common/template.h"
 #include "flang/Evaluate/common.h"
 #include "flang/Evaluate/type.h"
+#include "flang/Support/template.h"
 
 namespace Fortran::evaluate {
 

diff --git a/flang/lib/Frontend/CompilerInstance.cpp b/flang/lib/Frontend/CompilerInstance.cpp
@@ -11,12 +11,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/CompilerInstance.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Frontend/CompilerInvocation.h"
 #include "flang/Frontend/TextDiagnosticPrinter.h"
 #include "flang/Parser/parsing.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/Fortran-features.h"
 #include "clang/Basic/DiagnosticFrontend.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/MC/TargetRegistry.h"

diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -11,13 +11,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/CompilerInvocation.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/OpenMP-features.h"
-#include "flang/Common/Version.h"
 #include "flang/Frontend/CodeGenOptions.h"
 #include "flang/Frontend/PreprocessorOptions.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/OpenMP-features.h"
+#include "flang/Support/Version.h"
 #include "flang/Tools/TargetSetup.h"
 #include "flang/Version.inc"
 #include "clang/Basic/AllDiagnostics.h"

diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
@@ -11,7 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Frontend/FrontendActions.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Frontend/CompilerInstance.h"
 #include "flang/Frontend/CompilerInvocation.h"
 #include "flang/Frontend/FrontendOptions.h"
@@ -33,6 +32,7 @@
 #include "flang/Semantics/runtime-type-info.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/unparse-with-symbols.h"
+#include "flang/Support/default-kinds.h"
 #include "flang/Tools/CrossToolHelpers.h"
 
 #include "mlir/IR/Dialect.h"

diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
@@ -12,7 +12,6 @@
 
 #include "flang/Lower/Bridge.h"
 #include "DirectivesCommon.h"
-#include "flang/Common/Version.h"
 #include "flang/Lower/Allocatable.h"
 #include "flang/Lower/CallInterface.h"
 #include "flang/Lower/Coarray.h"
@@ -59,6 +58,7 @@
 #include "flang/Semantics/runtime-type-info.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Version.h"
 #include "mlir/Dialect/ControlFlow/IR/ControlFlowOps.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/IR/PatternMatch.h"

diff --git a/flang/lib/Lower/CallInterface.cpp b/flang/lib/Lower/CallInterface.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Lower/CallInterface.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Lower/Bridge.h"
 #include "flang/Lower/Mangler.h"
@@ -23,6 +22,7 @@
 #include "flang/Optimizer/Support/Utils.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 
 static mlir::FunctionType

diff --git a/flang/lib/Lower/ConvertExpr.cpp b/flang/lib/Lower/ConvertExpr.cpp
@@ -11,8 +11,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Lower/ConvertExpr.h"
-#include "flang/Common/default-kinds.h"
-#include "flang/Common/unwrap.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/real.h"
 #include "flang/Evaluate/traverse.h"
@@ -52,6 +50,8 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/default-kinds.h"
+#include "flang/Support/unwrap.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/Support/CommandLine.h"

diff --git a/flang/lib/Lower/Mangler.cpp b/flang/lib/Lower/Mangler.cpp
@@ -7,12 +7,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Lower/Mangler.h"
-#include "flang/Common/reference.h"
 #include "flang/Lower/Support/Utils.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/reference.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"

diff --git a/flang/lib/Optimizer/Builder/IntrinsicCall.cpp b/flang/lib/Optimizer/Builder/IntrinsicCall.cpp
@@ -14,7 +14,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Builder/IntrinsicCall.h"
-#include "flang/Common/static-multimap-view.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/Character.h"
 #include "flang/Optimizer/Builder/Complex.h"
@@ -42,6 +41,7 @@
 #include "flang/Optimizer/Support/Utils.h"
 #include "flang/Runtime/entry-names.h"
 #include "flang/Runtime/iostat.h"
+#include "flang/Support/static-multimap-view.h"
 #include "mlir/Dialect/Complex/IR/Complex.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/Dialect/Math/IR/Math.h"

diff --git a/flang/lib/Optimizer/CodeGen/TypeConverter.cpp b/flang/lib/Optimizer/CodeGen/TypeConverter.cpp
@@ -13,7 +13,6 @@
 #define DEBUG_TYPE "flang-type-conversion"
 
 #include "flang/Optimizer/CodeGen/TypeConverter.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/Todo.h" // remove when TODO's are done
 #include "flang/Optimizer/CodeGen/DescriptorModel.h"
 #include "flang/Optimizer/CodeGen/TBAABuilder.h"
@@ -22,6 +21,7 @@
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"
 #include "flang/Optimizer/Support/InternalNames.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Conversion/LLVMCommon/TypeConverter.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/Debug.h"

diff --git a/flang/lib/Optimizer/Dialect/FIRType.cpp b/flang/lib/Optimizer/Dialect/FIRType.cpp
@@ -11,7 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Optimizer/Dialect/FIRType.h"
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/Support/KindMapping.h"

diff --git a/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp b/flang/lib/Optimizer/Transforms/AddDebugInfo.cpp
@@ -12,7 +12,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "DebugTypeGenerator.h"
-#include "flang/Common/Version.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Todo.h"
 #include "flang/Optimizer/CodeGen/CGOps.h"
@@ -22,6 +21,7 @@
 #include "flang/Optimizer/Dialect/Support/FIRContext.h"
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Optimizer/Transforms/Passes.h"
+#include "flang/Support/Version.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Matchers.h"

diff --git a/flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp b/flang/lib/Optimizer/Transforms/AssumedRankOpConversion.cpp
@@ -6,7 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Lower/BuiltinModules.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Runtime/Support.h"
@@ -17,6 +16,7 @@
 #include "flang/Optimizer/Support/Utils.h"
 #include "flang/Optimizer/Transforms/Passes.h"
 #include "flang/Runtime/support.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Transforms/DialectConversion.h"

diff --git a/flang/lib/Optimizer/Transforms/CufOpConversion.cpp b/flang/lib/Optimizer/Transforms/CufOpConversion.cpp
@@ -6,7 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/Runtime/RTBuilder.h"
 #include "flang/Optimizer/CodeGen/TypeConverter.h"
 #include "flang/Optimizer/Dialect/CUF/CUFOps.h"
@@ -16,6 +15,7 @@
 #include "flang/Optimizer/Support/DataLayout.h"
 #include "flang/Runtime/CUDA/descriptor.h"
 #include "flang/Runtime/allocatable.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Pass/Pass.h"
 #include "mlir/Transforms/DialectConversion.h"
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"

diff --git a/flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp b/flang/lib/Optimizer/Transforms/ExternalNameConversion.cpp
@@ -6,12 +6,12 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Dialect/FIROpsSupport.h"
 #include "flang/Optimizer/Support/InternalNames.h"
 #include "flang/Optimizer/Transforms/Passes.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/IR/Attributes.h"
 #include "mlir/IR/SymbolTable.h"
 #include "mlir/Pass/Pass.h"

diff --git a/flang/lib/Optimizer/Transforms/LoopVersioning.cpp b/flang/lib/Optimizer/Transforms/LoopVersioning.cpp
@@ -40,7 +40,7 @@
 ///       could be part of the cost analysis above.
 //===----------------------------------------------------------------------===//
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Runtime/Inquiry.h"

diff --git a/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp b/flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp
@@ -22,7 +22,6 @@
 /// and small in size.
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/LowLevelIntrinsics.h"
@@ -34,6 +33,7 @@
 #include "flang/Optimizer/Transforms/Passes.h"
 #include "flang/Optimizer/Transforms/Utils.h"
 #include "flang/Runtime/entry-names.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/IR/Operation.h"

diff --git a/flang/lib/Optimizer/Transforms/StackReclaim.cpp b/flang/lib/Optimizer/Transforms/StackReclaim.cpp
@@ -6,10 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
 #include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
 #include "flang/Optimizer/Transforms/Passes.h"
+#include "flang/Support/Fortran.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/IR/Matchers.h"
 #include "mlir/Pass/Pass.h"

diff --git a/flang/lib/Optimizer/Transforms/VScaleAttr.cpp b/flang/lib/Optimizer/Transforms/VScaleAttr.cpp
@@ -14,7 +14,7 @@
 /// likely harmless to run it on something else, but it is also not valuable].
 //===----------------------------------------------------------------------===//
 
-#include "flang/ISO_Fortran_binding_wrapper.h"
+#include "flang/Common/ISO_Fortran_binding_wrapper.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
 #include "flang/Optimizer/Builder/Runtime/Inquiry.h"

diff --git a/flang/lib/Parser/basic-parsers.h b/flang/lib/Parser/basic-parsers.h
@@ -22,14 +22,14 @@
 // This header defines the fundamental parser class templates and helper
 // template functions.  See parser-combinators.txt for documentation.
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
 #include "flang/Parser/char-block.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/parse-state.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Parser/user-state.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/indirection.h"
 #include <cstring>
 #include <functional>
 #include <list>

diff --git a/flang/lib/Parser/parse-tree.cpp b/flang/lib/Parser/parse-tree.cpp
@@ -8,9 +8,9 @@
 
 #include "flang/Parser/parse-tree.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
 #include "flang/Parser/tools.h"
 #include "flang/Parser/user-state.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 

diff --git a/flang/lib/Parser/prescan.h b/flang/lib/Parser/prescan.h
@@ -16,11 +16,11 @@
 // fixed form character literals on truncated card images, file
 // inclusion, and driving the Fortran source preprocessor.
 
-#include "flang/Common/Fortran-features.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Parser/token-sequence.h"
+#include "flang/Support/Fortran-features.h"
 #include <bitset>
 #include <optional>
 #include <string>

diff --git a/flang/lib/Parser/unparse.cpp b/flang/lib/Parser/unparse.cpp
@@ -10,13 +10,13 @@
 // traversal templates in parse-tree-visitor.h.
 
 #include "flang/Parser/unparse.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cinttypes>

diff --git a/flang/lib/Semantics/assignment.h b/flang/lib/Semantics/assignment.h
@@ -9,9 +9,9 @@
 #ifndef FORTRAN_SEMANTICS_ASSIGNMENT_H_
 #define FORTRAN_SEMANTICS_ASSIGNMENT_H_
 
-#include "flang/Common/indirection.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/indirection.h"
 
 namespace Fortran::parser {
 class ContextualMessages;

diff --git a/flang/lib/Semantics/check-case.cpp b/flang/lib/Semantics/check-case.cpp
@@ -8,13 +8,13 @@
 
 #include "check-case.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/reference.h"
-#include "flang/Common/template.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/type.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/reference.h"
+#include "flang/Support/template.h"
 #include <tuple>
 
 namespace Fortran::semantics {

diff --git a/flang/lib/Semantics/check-coarray.cpp b/flang/lib/Semantics/check-coarray.cpp
@@ -7,13 +7,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-coarray.h"
-#include "flang/Common/indirection.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/indirection.h"
 
 namespace Fortran::semantics {
 

diff --git a/flang/lib/Semantics/check-cuda.cpp b/flang/lib/Semantics/check-cuda.cpp
@@ -7,7 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-cuda.h"
-#include "flang/Common/template.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/tools.h"
 #include "flang/Evaluate/traverse.h"
@@ -17,6 +16,7 @@
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/template.h"
 
 // Once labeled DO constructs have been canonicalized and their parse subtrees
 // transformed into parser::DoConstructs, scan the parser::Blocks of the program

diff --git a/flang/lib/Semantics/check-data.h b/flang/lib/Semantics/check-data.h
@@ -10,11 +10,11 @@
 #define FORTRAN_SEMANTICS_CHECK_DATA_H_
 
 #include "data-to-inits.h"
-#include "flang/Common/interval.h"
 #include "flang/Evaluate/fold-designator.h"
 #include "flang/Evaluate/initial-image.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/interval.h"
 #include <list>
 #include <map>
 #include <vector>

diff --git a/flang/lib/Semantics/check-do-forall.cpp b/flang/lib/Semantics/check-do-forall.cpp
@@ -8,7 +8,6 @@
 
 #include "check-do-forall.h"
 #include "definable.h"
-#include "flang/Common/template.h"
 #include "flang/Evaluate/call.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/tools.h"
@@ -22,6 +21,7 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/template.h"
 
 namespace Fortran::evaluate {
 using ActualArgumentRef = common::Reference<const ActualArgument>;

diff --git a/flang/lib/Semantics/check-return.cpp b/flang/lib/Semantics/check-return.cpp
@@ -7,11 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-return.h"
-#include "flang/Common/Fortran-features.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran-features.h"
 
 namespace Fortran::semantics {
 

diff --git a/flang/lib/Semantics/check-select-rank.cpp b/flang/lib/Semantics/check-select-rank.cpp
@@ -7,11 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-select-rank.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/tools.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include <list>
 #include <optional>
 #include <set>

diff --git a/flang/lib/Semantics/check-select-type.cpp b/flang/lib/Semantics/check-select-type.cpp
@@ -8,12 +8,12 @@
 
 #include "check-select-type.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/reference.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/type.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/reference.h"
 #include <optional>
 
 namespace Fortran::semantics {

diff --git a/flang/lib/Semantics/check-stop.cpp b/flang/lib/Semantics/check-stop.cpp
@@ -7,11 +7,11 @@
 //===----------------------------------------------------------------------===//
 
 #include "check-stop.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include <optional>
 
 namespace Fortran::semantics {

diff --git a/flang/lib/Semantics/data-to-inits.h b/flang/lib/Semantics/data-to-inits.h
@@ -9,10 +9,10 @@
 #ifndef FORTRAN_SEMANTICS_DATA_TO_INITS_H_
 #define FORTRAN_SEMANTICS_DATA_TO_INITS_H_
 
-#include "flang/Common/default-kinds.h"
-#include "flang/Common/interval.h"
 #include "flang/Evaluate/fold-designator.h"
 #include "flang/Evaluate/initial-image.h"
+#include "flang/Support/default-kinds.h"
+#include "flang/Support/interval.h"
 #include <list>
 #include <map>
 

diff --git a/flang/lib/Semantics/expression.cpp b/flang/lib/Semantics/expression.cpp
@@ -11,7 +11,6 @@
 #include "pointer-assignment.h"
 #include "resolve-names-utils.h"
 #include "resolve-names.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
 #include "flang/Evaluate/common.h"
 #include "flang/Evaluate/fold.h"
@@ -24,6 +23,7 @@
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <functional>

diff --git a/flang/lib/Semantics/pointer-assignment.cpp b/flang/lib/Semantics/pointer-assignment.cpp
@@ -10,7 +10,6 @@
 #include "definable.h"
 #include "flang/Common/idioms.h"
 #include "flang/Common/restorer.h"
-#include "flang/Common/template.h"
 #include "flang/Evaluate/characteristics.h"
 #include "flang/Evaluate/expression.h"
 #include "flang/Evaluate/fold.h"
@@ -21,6 +20,7 @@
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/template.h"
 #include "llvm/Support/raw_ostream.h"
 #include <optional>
 #include <set>

diff --git a/flang/lib/Semantics/resolve-labels.cpp b/flang/lib/Semantics/resolve-labels.cpp
@@ -8,9 +8,9 @@
 
 #include "resolve-labels.h"
 #include "flang/Common/enum-set.h"
-#include "flang/Common/template.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Semantics/semantics.h"
+#include "flang/Support/template.h"
 #include <cstdarg>
 #include <type_traits>
 

diff --git a/flang/lib/Semantics/resolve-names-utils.cpp b/flang/lib/Semantics/resolve-names-utils.cpp
@@ -7,10 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "resolve-names-utils.h"
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
 #include "flang/Common/idioms.h"
-#include "flang/Common/indirection.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/tools.h"
 #include "flang/Evaluate/traverse.h"
@@ -20,6 +17,9 @@
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include <initializer_list>
 #include <variant>
 

diff --git a/flang/lib/Semantics/resolve-names.cpp b/flang/lib/Semantics/resolve-names.cpp
@@ -14,9 +14,6 @@
 #include "resolve-directives.h"
 #include "resolve-names-utils.h"
 #include "rewrite-parse-tree.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/default-kinds.h"
-#include "flang/Common/indirection.h"
 #include "flang/Common/restorer.h"
 #include "flang/Common/visit.h"
 #include "flang/Evaluate/characteristics.h"
@@ -37,6 +34,9 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/default-kinds.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <list>
 #include <map>

diff --git a/flang/lib/Semantics/rewrite-parse-tree.cpp b/flang/lib/Semantics/rewrite-parse-tree.cpp
@@ -8,14 +8,14 @@
 
 #include "rewrite-parse-tree.h"
 #include "rewrite-directives.h"
-#include "flang/Common/indirection.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/parse-tree.h"
 #include "flang/Parser/tools.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
+#include "flang/Support/indirection.h"
 #include <list>
 
 namespace Fortran::semantics {

diff --git a/flang/lib/Semantics/semantics.cpp b/flang/lib/Semantics/semantics.cpp
@@ -37,12 +37,12 @@
 #include "resolve-labels.h"
 #include "resolve-names.h"
 #include "rewrite-parse-tree.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/parse-tree-visitor.h"
 #include "flang/Parser/tools.h"
 #include "flang/Semantics/expression.h"
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/symbol.h"
+#include "flang/Support/default-kinds.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TargetParser/Host.h"
 #include "llvm/TargetParser/Triple.h"

diff --git a/flang/lib/Semantics/tools.cpp b/flang/lib/Semantics/tools.cpp
@@ -7,8 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "flang/Parser/tools.h"
-#include "flang/Common/Fortran.h"
-#include "flang/Common/indirection.h"
 #include "flang/Parser/dump-parse-tree.h"
 #include "flang/Parser/message.h"
 #include "flang/Parser/parse-tree.h"
@@ -17,6 +15,8 @@
 #include "flang/Semantics/symbol.h"
 #include "flang/Semantics/tools.h"
 #include "flang/Semantics/type.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/indirection.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <set>

diff --git a/flang/lib/Common/Fortran-features.cpp → flang/lib/Support/Fortran-features.cpp b/flang/lib/Common/Fortran-features.cpp → flang/lib/Support/Fortran-features.cpp
@@ -1,14 +1,14 @@
-//===-- lib/Common/Fortran-features.cpp -----------------------------------===//
+//===-- lib/Support/Fortran-features.cpp ------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/Fortran.h"
+#include "flang/Support/Fortran-features.h"
 #include "flang/Common/idioms.h"
+#include "flang/Support/Fortran.h"
 
 namespace Fortran::common {
 

diff --git a/flang/lib/Common/Fortran.cpp → flang/lib/Support/Fortran.cpp b/flang/lib/Common/Fortran.cpp → flang/lib/Support/Fortran.cpp
@@ -1,13 +1,13 @@
-//===-- lib/Common/Fortran.cpp --------------------------------------------===//
+//===-- lib/Support/Fortran.cpp ---------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran.h"
-#include "flang/Common/Fortran-features.h"
+#include "flang/Support/Fortran.h"
+#include "flang/Support/Fortran-features.h"
 
 namespace Fortran::common {
 

diff --git a/flang/lib/Common/Version.cpp → flang/lib/Support/Version.cpp b/flang/lib/Common/Version.cpp → flang/lib/Support/Version.cpp
@@ -1,4 +1,4 @@
-//===- Version.cpp - Flang Version Number -------------------*- Fortran -*-===//
+//===-- lib/Support/Version.cpp ---------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -10,7 +10,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Version.h"
+#include "flang/Support/Version.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdlib>
 #include <cstring>

diff --git a/flang/lib/Common/default-kinds.cpp → flang/lib/Support/default-kinds.cpp b/flang/lib/Common/default-kinds.cpp → flang/lib/Support/default-kinds.cpp
@@ -1,12 +1,12 @@
-//===-- lib/Common/default-kinds.cpp --------------------------------------===//
+//===-- lib/Support/default-kinds.cpp ---------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/default-kinds.h"
+#include "flang/Support/default-kinds.h"
 #include "flang/Common/idioms.h"
 
 namespace Fortran::common {

diff --git a/flang/lib/Common/idioms.cpp → flang/lib/Support/idioms.cpp b/flang/lib/Common/idioms.cpp → flang/lib/Support/idioms.cpp
@@ -1,4 +1,4 @@
-//===-- lib/Common/idioms.cpp ---------------------------------------------===//
+//===-- lib/Support/idioms.cpp ----------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/module/__fortran_builtins.f90 b/flang/module/__fortran_builtins.f90
@@ -6,7 +6,7 @@
 !
 !===------------------------------------------------------------------------===!
 
-#include '../include/flang/Runtime/magic-numbers.h'
+#include '../../FortranRuntime/include/flang/Common/magic-numbers.h'
 
 ! These naming shenanigans prevent names from Fortran intrinsic modules
 ! from being usable on INTRINSIC statements, and force the program

diff --git a/flang/module/__fortran_ieee_exceptions.f90 b/flang/module/__fortran_ieee_exceptions.f90
@@ -11,7 +11,7 @@
 ! here under another name so that IEEE_ARITHMETIC can USE it and export its
 ! declarations without clashing with a non-intrinsic module in a program.
 
-#include '../include/flang/Runtime/magic-numbers.h'
+#include '../../FortranRuntime/include/flang/Common/magic-numbers.h'
 
 module __fortran_ieee_exceptions
   use __fortran_builtins, only: &

diff --git a/flang/module/cudadevice.f90 b/flang/module/cudadevice.f90
@@ -1,4 +1,4 @@
-!===-- module/cudedevice.f90 -----------------------------------------------===!
+!===-- module/cudadevice.f90 -----------------------------------------------===!
 !
 ! Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 ! See https://llvm.org/LICENSE.txt for license information.

diff --git a/flang/module/ieee_arithmetic.f90 b/flang/module/ieee_arithmetic.f90
@@ -8,7 +8,7 @@
 
 ! Fortran 2018 Clause 17
 
-#include '../include/flang/Runtime/magic-numbers.h'
+#include '../../FortranRuntime/include/flang/Common/magic-numbers.h'
 
 module ieee_arithmetic
   ! F18 Clause 17.1p1:

diff --git a/flang/module/iso_fortran_env.f90 b/flang/module/iso_fortran_env.f90
@@ -8,7 +8,7 @@
 
 ! See Fortran 2023, subclause 16.10.2
 
-#include '../include/flang/Runtime/magic-numbers.h'
+#include '../../FortranRuntime/include/flang/Common/magic-numbers.h'
 
 module iso_fortran_env
 

diff --git a/flang/module/mma.f90 b/flang/module/mma.f90
@@ -55,9 +55,18 @@ pure __vector_pair function func_vpi0vp(arg1, arg2); \
     !dir$ ignore_tkr(r) arg2; \
   end function;
 
-  FUNC_VPI0VI(1) FUNC_VPI0VI(2) FUNC_VPI0VI(4) FUNC_VPI0VI(8)
-  FUNC_VPI0VU(1) FUNC_VPI0VU(2) FUNC_VPI0VU(4) FUNC_VPI0VU(8)
-  FUNC_VPI0VR(4) FUNC_VPI0VR(8)
+! FIXME: Potential Flang bug: combining multiple of those on a single line breaks after preprocessing as an explicit step as done by CMake
+! Line counting is also wrong
+  FUNC_VPI0VI(1)
+  FUNC_VPI0VI(2)
+  FUNC_VPI0VI(4)
+  FUNC_VPI0VI(8)
+  FUNC_VPI0VU(1)
+  FUNC_VPI0VU(2)
+  FUNC_VPI0VU(4)
+  FUNC_VPI0VU(8)
+  FUNC_VPI0VR(4)
+  FUNC_VPI0VR(8)
   FUNC_VPI0VP
 
 #undef FUNC_VPI0VP
@@ -144,14 +153,26 @@ elemental subroutine sub_vpvr##VKIND##vr##VKIND(pair, arg1, arg2); \
     vector(real(VKIND)), intent(in) :: arg1, arg2; \
   end subroutine ;
 
-  ELEM_SUB_VPVIVI(1) ELEM_SUB_VPVIVI(2)
-  ELEM_SUB_VPVIVI(4) ELEM_SUB_VPVIVI(8)
-  ELEM_SUB_VPVUVU(1) ELEM_SUB_VPVUVU(2)
-  ELEM_SUB_VPVUVU(4) ELEM_SUB_VPVUVU(8)
-  ELEM_SUB_VPVRVR(4) ELEM_SUB_VPVRVR(8)
-  SUB_VPI0VI(1) SUB_VPI0VI(2) SUB_VPI0VI(4) SUB_VPI0VI(8)
-  SUB_VPI0VU(1) SUB_VPI0VU(2) SUB_VPI0VU(4) SUB_VPI0VU(8)
-  SUB_VPI0VR(4) SUB_VPI0VR(8)
+  ELEM_SUB_VPVIVI(1)
+  ELEM_SUB_VPVIVI(2)
+  ELEM_SUB_VPVIVI(4)
+  ELEM_SUB_VPVIVI(8)
+  ELEM_SUB_VPVUVU(1)
+  ELEM_SUB_VPVUVU(2)
+  ELEM_SUB_VPVUVU(4)
+  ELEM_SUB_VPVUVU(8)
+  ELEM_SUB_VPVRVR(4)
+  ELEM_SUB_VPVRVR(8)
+  SUB_VPI0VI(1)
+  SUB_VPI0VI(2)
+  SUB_VPI0VI(4)
+  SUB_VPI0VI(8)
+  SUB_VPI0VU(1)
+  SUB_VPI0VU(2)
+  SUB_VPI0VU(4)
+  SUB_VPI0VU(8)
+  SUB_VPI0VR(4)
+  SUB_VPI0VR(8)
 
 #undef ELEM_SUB_VPVIVI
 #undef ELEM_SUB_VPVUVU

diff --git a/flang/test/lit.cfg.py b/flang/test/lit.cfg.py
@@ -169,7 +169,7 @@
 if config.cc:
     libruntime = os.path.join(config.flang_lib_dir, "libFortranRuntime.a")
     libdecimal = os.path.join(config.flang_lib_dir, "libFortranDecimal.a")
-    include = os.path.join(config.flang_src_dir, "include")
+    include = os.path.join(config.flang_src_dir, "..", "FortranRuntime", "include")
 
     if (
         os.path.isfile(libruntime)

diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
@@ -14,10 +14,6 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/OpenMP-features.h"
-#include "flang/Common/Version.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Frontend/TargetOptions.h"
 #include "flang/Lower/Bridge.h"
 #include "flang/Lower/PFTBuilder.h"
@@ -40,6 +36,10 @@
 #include "flang/Semantics/runtime-type-info.h"
 #include "flang/Semantics/semantics.h"
 #include "flang/Semantics/unparse-with-symbols.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/OpenMP-features.h"
+#include "flang/Support/Version.h"
+#include "flang/Support/default-kinds.h"
 #include "flang/Tools/CrossToolHelpers.h"
 #include "flang/Tools/TargetSetup.h"
 #include "flang/Version.inc"

diff --git a/flang/tools/f18-parse-demo/f18-parse-demo.cpp b/flang/tools/f18-parse-demo/f18-parse-demo.cpp
@@ -21,8 +21,6 @@
 // scaffolding compiler driver that can test some semantic passes of the
 // F18 compiler under development.
 
-#include "flang/Common/Fortran-features.h"
-#include "flang/Common/default-kinds.h"
 #include "flang/Parser/characters.h"
 #include "flang/Parser/dump-parse-tree.h"
 #include "flang/Parser/message.h"
@@ -31,6 +29,8 @@
 #include "flang/Parser/parsing.h"
 #include "flang/Parser/provenance.h"
 #include "flang/Parser/unparse.h"
+#include "flang/Support/Fortran-features.h"
+#include "flang/Support/default-kinds.h"
 #include "llvm/Support/Errno.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Program.h"

diff --git a/flang/tools/f18/CMakeLists.txt b/flang/tools/f18/CMakeLists.txt
@@ -105,19 +105,21 @@ if (NOT CMAKE_CROSSCOMPILING)
     set(compile_with "-fsyntax-only")
     set(object_output "")
     set(include_in_link FALSE)
+    set(fullpath "${FLANG_SOURCE_DIR}/module/${filename}.f90")
     if(${filename} IN_LIST MODULES_WITH_IMPLEMENTATION)
       set(object_output "${CMAKE_CURRENT_BINARY_DIR}/${filename}${CMAKE_CXX_OUTPUT_EXTENSION}")
       set(compile_with -c -o ${object_output})
       set(include_in_link TRUE)
+      set(fullpath "${FLANG_SOURCE_DIR}/../FortranRuntime/lib/Runtime/${filename}.f90")
     endif()
 
     set(base ${FLANG_INTRINSIC_MODULES_DIR}/${filename})
     # TODO: We may need to flag this with conditional, in case Flang is built w/o OpenMP support
     add_custom_command(OUTPUT ${base}.mod ${object_output}
       COMMAND ${CMAKE_COMMAND} -E make_directory ${FLANG_INTRINSIC_MODULES_DIR}
       COMMAND flang-new ${opts} ${decls} -cpp ${compile_with} -module-dir ${FLANG_INTRINSIC_MODULES_DIR}
-        ${FLANG_SOURCE_DIR}/module/${filename}.f90
-      DEPENDS flang-new ${FLANG_SOURCE_DIR}/module/${filename}.f90 ${FLANG_SOURCE_DIR}/module/__fortran_builtins.f90 ${depends}
+        ${fullpath}
+      DEPENDS flang-new ${fullpath} ${FLANG_SOURCE_DIR}/module/__fortran_builtins.f90 ${depends}
     )
     list(APPEND MODULE_FILES ${base}.mod)
     install(FILES ${base}.mod DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/flang")

diff --git a/flang/unittests/CMakeLists.txt b/flang/unittests/CMakeLists.txt
@@ -72,8 +72,8 @@ function(add_flang_nongtest_unittest test_name)
 endfunction()
 
 add_subdirectory(Optimizer)
-add_subdirectory(Common)
-add_subdirectory(Decimal)
+add_subdirectory(../../FortranRuntime/unittests/Common Common)
+add_subdirectory(../../FortranRuntime/unittests/Decimal Decimal)
 add_subdirectory(Evaluate)
-add_subdirectory(Runtime)
+add_subdirectory(../../FortranRuntime/unittests/Runtime Runtime)
 add_subdirectory(Frontend)
diff --git a/flang/unittests/Common/CMakeLists.txt b/flang/unittests/Common/CMakeLists.txt
diff --git a/flang/unittests/Decimal/CMakeLists.txt b/flang/unittests/Decimal/CMakeLists.txt
diff --git a/flang/unittests/Evaluate/CMakeLists.txt b/flang/unittests/Evaluate/CMakeLists.txt
@@ -1,7 +1,7 @@
 set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 add_library(FortranEvaluateTesting
-  testing.cpp
-  fp-testing.cpp
+  ../../../FortranRuntime/lib/Testing/testing.cpp
+  ../../../FortranRuntime/lib/Testing/fp-testing.cpp
 )
 set_target_properties(FortranEvaluateTesting PROPERTIES FOLDER "Flang/Tests")
 if (LLVM_LINK_LLVM_DYLIB)
@@ -69,23 +69,11 @@ add_flang_nongtest_unittest(real
 )
 llvm_update_compile_flags(real.test)
 
-add_flang_nongtest_unittest(reshape
-  FortranEvaluateTesting
-  FortranSemantics
-  FortranEvaluate
-  FortranRuntime
-)
-
-add_flang_nongtest_unittest(ISO-Fortran-binding
-  FortranEvaluateTesting
-  FortranEvaluate
-  FortranSemantics
-  FortranRuntime
-)
-
 add_flang_nongtest_unittest(folding
   FortranCommon
   FortranEvaluateTesting
   FortranEvaluate
   FortranSemantics
 )
+
+add_subdirectory(../../../FortranRuntime/unittests/Evaluate runtime)
diff --git a/flang/unittests/Evaluate/bit-population-count.cpp b/flang/unittests/Evaluate/bit-population-count.cpp
@@ -1,5 +1,5 @@
 #include "flang/Common/bit-population-count.h"
-#include "testing.h"
+#include "flang/Testing/testing.h"
 
 using Fortran::common::BitPopulationCount;
 using Fortran::common::Parity;

diff --git a/flang/unittests/Evaluate/expression.cpp b/flang/unittests/Evaluate/expression.cpp
@@ -1,10 +1,10 @@
 #include "flang/Evaluate/expression.h"
-#include "testing.h"
 #include "flang/Evaluate/fold.h"
 #include "flang/Evaluate/intrinsics.h"
 #include "flang/Evaluate/target.h"
 #include "flang/Evaluate/tools.h"
 #include "flang/Parser/message.h"
+#include "flang/Testing/testing.h"
 #include <cstdio>
 #include <cstdlib>
 #include <string>

diff --git a/flang/unittests/Evaluate/folding.cpp b/flang/unittests/Evaluate/folding.cpp
@@ -1,4 +1,3 @@
-#include "testing.h"
 #include "../../lib/Evaluate/host.h"
 #include "flang/Evaluate/call.h"
 #include "flang/Evaluate/expression.h"
@@ -7,6 +6,7 @@
 #include "flang/Evaluate/intrinsics.h"
 #include "flang/Evaluate/target.h"
 #include "flang/Evaluate/tools.h"
+#include "flang/Testing/testing.h"
 #include <tuple>
 
 using namespace Fortran::evaluate;

diff --git a/flang/unittests/Evaluate/fp-testing.h b/flang/unittests/Evaluate/fp-testing.h