ARM, AArch64: support `__attribute__((__swiftcall__))`

Support the Swift calling convention on Windows ARM and AArch64.  Both
of these conform to the AAPCS, AAPCS64 calling convention, and LLVM has
been adjusted to account for the register usage.  Ensure that the
frontend passes this into the backend.  This allows the swift runtime to
be built for Windows.

llvm-svn: 348454

2 files changed, 2 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index e64eb21a49f..376cba6e455 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -514,6 +514,7 @@ WindowsARM64TargetInfo::checkCallingConvention(CallingConv CC) const {
   case CC_OpenCLKernel:
   case CC_PreserveMost:
   case CC_PreserveAll:
+  case CC_Swift:
   case CC_Win64:
     return CCCR_OK;
   default:
diff --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
index 5345d1f8e9d..cb202eac985 100644
--- a/clang/lib/Basic/Targets/ARM.cpp
+++ b/clang/lib/Basic/Targets/ARM.cpp
@@ -996,6 +996,7 @@ WindowsARMTargetInfo::checkCallingConvention(CallingConv CC) const {
   case CC_OpenCLKernel:
   case CC_PreserveMost:
   case CC_PreserveAll:
+  case CC_Swift:
     return CCCR_OK;
   default:
     return CCCR_Warning;