Swift 5.6 patched for RISCV64

swift-5.6-riscv64.patch

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bc9b6790922..6cc8149e184 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -724,6 +724,8 @@ else()
     set(SWIFT_HOST_VARIANT_ARCH_default "i686")
   elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "wasm32")
     set(SWIFT_HOST_VARIANT_ARCH_default "wasm32")
+  elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "riscv64")
+    set(SWIFT_HOST_VARIANT_ARCH_default "riscv64")
   else()
     message(FATAL_ERROR "Unrecognized architecture on host system: ${CMAKE_SYSTEM_PROCESSOR}")
   endif()
diff --git a/cmake/modules/SwiftConfigureSDK.cmake b/cmake/modules/SwiftConfigureSDK.cmake
index 3c866f2e65c..21d325c07c7 100644
--- a/cmake/modules/SwiftConfigureSDK.cmake
+++ b/cmake/modules/SwiftConfigureSDK.cmake
@@ -325,7 +325,7 @@ macro(configure_sdk_unix name architectures)
       if("${prefix}" STREQUAL "LINUX")
         if(arch MATCHES "(armv6|armv7)")
           set(SWIFT_SDK_LINUX_ARCH_${arch}_TRIPLE "${arch}-unknown-linux-gnueabihf")
-        elseif(arch MATCHES "(aarch64|i686|powerpc64|powerpc64le|s390x|x86_64)")
+        elseif(arch MATCHES "(aarch64|i686|powerpc64|powerpc64le|s390x|x86_64|riscv64)")
           set(SWIFT_SDK_LINUX_ARCH_${arch}_TRIPLE "${arch}-unknown-linux-gnu")
         else()
           message(FATAL_ERROR "unknown arch for ${prefix}: ${arch}")
diff --git a/cmake/modules/SwiftSetIfArchBitness.cmake b/cmake/modules/SwiftSetIfArchBitness.cmake
index fa29d77fe26..d43050d2a6e 100644
--- a/cmake/modules/SwiftSetIfArchBitness.cmake
+++ b/cmake/modules/SwiftSetIfArchBitness.cmake
@@ -23,7 +23,8 @@ function(set_if_arch_bitness var_name)
          "${SIA_ARCH}" STREQUAL "aarch64" OR
          "${SIA_ARCH}" STREQUAL "powerpc64" OR
          "${SIA_ARCH}" STREQUAL "powerpc64le" OR
-         "${SIA_ARCH}" STREQUAL "s390x")
+         "${SIA_ARCH}" STREQUAL "s390x" OR
+         "${SIA_ARCH}" STREQUAL "riscv64")
     set("${var_name}" "${SIA_CASE_64_BIT}" PARENT_SCOPE)
   else()
     message(FATAL_ERROR "Unknown architecture: ${SIA_ARCH}")
diff --git a/lib/Basic/LangOptions.cpp b/lib/Basic/LangOptions.cpp
index b9e8b488d9c..04ce2b64444 100644
--- a/lib/Basic/LangOptions.cpp
+++ b/lib/Basic/LangOptions.cpp
@@ -66,6 +66,7 @@ static const SupportedConditionalValue SupportedConditionalCompilationArches[] =
   "powerpc64le",
   "s390x",
   "wasm32",
+  "riscv64",
 };
 
 static const SupportedConditionalValue SupportedConditionalCompilationEndianness[] = {
@@ -312,6 +313,9 @@ std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
       addPlatformConditionValue(PlatformConditionKind::Arch, "arm64");
     }
     break;
+  case llvm::Triple::ArchType::riscv64:
+    addPlatformConditionValue(PlatformConditionKind::Arch, "riscv64");
+    break;
   case llvm::Triple::ArchType::ppc64:
     addPlatformConditionValue(PlatformConditionKind::Arch, "powerpc64");
     break;
@@ -346,6 +350,7 @@ std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
   case llvm::Triple::ArchType::aarch64_32:
   case llvm::Triple::ArchType::ppc64le:
   case llvm::Triple::ArchType::wasm32:
+  case llvm::Triple::ArchType::riscv64:
   case llvm::Triple::ArchType::x86:
   case llvm::Triple::ArchType::x86_64:
     addPlatformConditionValue(PlatformConditionKind::Endianness, "little");
diff --git a/stdlib/cmake/modules/SwiftSource.cmake b/stdlib/cmake/modules/SwiftSource.cmake
index 4bc312f7f89..322e7829578 100644
--- a/stdlib/cmake/modules/SwiftSource.cmake
+++ b/stdlib/cmake/modules/SwiftSource.cmake
@@ -520,6 +520,10 @@ function(_compile_swift_files
 
   list(APPEND swift_flags ${SWIFT_STDLIB_EXTRA_SWIFT_COMPILE_FLAGS})
 
+  if(CFLAGS_ARCH STREQUAL "riscv64")
+     list(APPEND swift_flags "-Xcc" "-mno-relax")
+  endif()
+
   list(APPEND swift_flags ${SWIFT_EXPERIMENTAL_EXTRA_FLAGS})
 
   if(SWIFTFILE_OPT_FLAGS)
diff --git a/stdlib/public/core/AtomicInt.swift.gyb b/stdlib/public/core/AtomicInt.swift.gyb
index a66212f4b35..1910009c996 100644
--- a/stdlib/public/core/AtomicInt.swift.gyb
+++ b/stdlib/public/core/AtomicInt.swift.gyb
@@ -68,7 +68,7 @@ internal func _swift_stdlib_atomicCompareExchangeStrongInt(
 #if arch(i386) || arch(arm) || arch(arm64_32) || arch(wasm32)
   let (oldValue, won) = Builtin.cmpxchg_seqcst_seqcst_Int32(
     target._rawValue, expected.pointee._value, desired._value)
-#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x)
+#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x) || arch(riscv64)
   let (oldValue, won) = Builtin.cmpxchg_seqcst_seqcst_Int64(
     target._rawValue, expected.pointee._value, desired._value)
 #endif
@@ -85,7 +85,7 @@ func _swift_stdlib_atomicLoadInt(
 #if arch(i386) || arch(arm) || arch(arm64_32) || arch(wasm32)
   let value = Builtin.atomicload_seqcst_Int32(target._rawValue)
   return Int(value)
-#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x)
+#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x) || arch(riscv64)
   let value = Builtin.atomicload_seqcst_Int64(target._rawValue)
   return Int(value)
 #endif
@@ -97,7 +97,7 @@ internal func _swift_stdlib_atomicStoreInt(
   desired: Int) {
 #if arch(i386) || arch(arm) || arch(arm64_32) || arch(wasm32)
   Builtin.atomicstore_seqcst_Int32(target._rawValue, desired._value)
-#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x)
+#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x) || arch(riscv64)
   Builtin.atomicstore_seqcst_Int64(target._rawValue, desired._value)
 #endif
 }
@@ -115,7 +115,7 @@ func _swift_stdlib_atomicFetch${operation}Int(
   let value = _swift_stdlib_atomicFetch${operation}Int32(
     object: rawTarget.assumingMemoryBound(to: Int32.self),
     operand: Int32(operand))
-#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x)
+#elseif arch(x86_64) || arch(arm64) || arch(powerpc64) || arch(powerpc64le) || arch(s390x) || arch(riscv64)
   let value = _swift_stdlib_atomicFetch${operation}Int64(
     object: rawTarget.assumingMemoryBound(to: Int64.self),
     operand: Int64(operand))
diff --git a/stdlib/public/core/Builtin.swift b/stdlib/public/core/Builtin.swift
index 8a7bb33243a..f74f5c7b769 100644
--- a/stdlib/public/core/Builtin.swift
+++ b/stdlib/public/core/Builtin.swift
@@ -389,7 +389,7 @@ internal var _objectPointerLowSpareBitShift: UInt {
 }
 
 #if arch(i386) || arch(arm) || arch(wasm32) || arch(powerpc64) || arch(
-  powerpc64le) || arch(s390x) || arch(arm64_32)
+  powerpc64le) || arch(s390x) || arch(arm64_32) || arch(riscv64)
 @inlinable
 internal var _objectPointerIsObjCBit: UInt {
     @inline(__always) get { return 0x0000_0002 }
diff --git a/stdlib/public/runtime/Float16Support.cpp b/stdlib/public/runtime/Float16Support.cpp
index 817739d4cdf..acc4cb93811 100644
--- a/stdlib/public/runtime/Float16Support.cpp
+++ b/stdlib/public/runtime/Float16Support.cpp
@@ -29,8 +29,8 @@
 
 // Android NDK <r21 do not provide `__aeabi_d2h` in the compiler runtime,
 // provide shims in that case.
-#if (defined(__ANDROID__) && defined(__ARM_ARCH_7A__) && defined(__ARM_EABI__)) || \
-  ((defined(__i386__) || defined(__i686__) || defined(__x86_64__)) && !defined(__APPLE__))
+#if ((defined(__ANDROID__) || defined(__linux__)) && defined(__arm__)) || \
+  ((defined(__i386__) || defined(__i686__) || defined(__x86_64__) || defined(__riscv)) && !defined(__APPLE__))
 
 #include "../SwiftShims/Visibility.h"
 
diff --git a/stdlib/public/runtime/HeapObject.cpp b/stdlib/public/runtime/HeapObject.cpp
index 0a276206225..74589177170 100644
--- a/stdlib/public/runtime/HeapObject.cpp
+++ b/stdlib/public/runtime/HeapObject.cpp
@@ -66,7 +66,7 @@ static inline bool isValidPointerForNativeRetain(const void *p) {
   // arm64_32 is special since it has 32-bit pointers but __arm64__ is true.
   // Catch it early since __POINTER_WIDTH__ is generally non-portable.
   return p != nullptr;
-#elif defined(__x86_64__) || defined(__arm64__) || defined(__aarch64__) || defined(_M_ARM64) || defined(__s390x__) || (defined(__powerpc64__) && defined(__LITTLE_ENDIAN__))
+#elif defined(__x86_64__) || defined(__arm64__) || defined(__aarch64__) || defined(_M_ARM64) || defined(__s390x__) || (defined(__powerpc64__) && defined(__LITTLE_ENDIAN__)) || defined(__riscv)
   // On these platforms, except s390x, the upper half of address space is reserved for the
   // kernel, so we can assume that pointer values in this range are invalid.
   // On s390x it is theoretically possible to have high bit set but in practice
diff --git a/stdlib/public/stubs/MathStubs.cpp b/stdlib/public/stubs/MathStubs.cpp
index 8d0617089ca..7ff97bc3687 100644
--- a/stdlib/public/stubs/MathStubs.cpp
+++ b/stdlib/public/stubs/MathStubs.cpp
@@ -64,6 +64,7 @@ extern "C" {
     (defined(__linux__) && defined(__aarch64__)) || \
     (defined(__linux__) && defined(__powerpc64__)) || \
     (defined(__linux__) && defined(__s390x__)) || \
+    (defined(__linux__) && defined(__riscv)) || \
     (defined(__ANDROID__) && defined(__aarch64__))
 
 SWIFT_RUNTIME_STDLIB_API
diff --git a/utils/build-presets.ini b/utils/build-presets.ini
index 64ba12b1e04..c2827b1212b 100644
--- a/utils/build-presets.ini
+++ b/utils/build-presets.ini
@@ -864,6 +864,7 @@ relocate-xdg-cache-home-under-build-subdir
 mixin-preset=
     mixin_linux_installation
 build-subdir=buildbot_linux
+llvm-targets-to-build=X86;ARM;AArch64;PowerPC;SystemZ;Mips;RISCV
 lldb
 release
 test
@@ -1481,7 +1482,7 @@ mixin-preset=
 [preset: LLDB_Nested]
 skip-build-benchmarks
 install-destdir=%(swift_install_destdir)s
-llvm-targets-to-build=X86;ARM;AArch64;PowerPC;SystemZ;Mips
+llvm-targets-to-build=X86;ARM;AArch64;PowerPC;SystemZ;Mips;RISCV
 
 [preset: LLDB_Swift_DebugAssert]
 mixin-preset=