Add XCore backend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58838 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/XCore/XCoreCallingConv.td

@@ -0,0 +1,33 @@
+//===- XCoreCallingConv.td - Calling Conventions for XCore -*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This describes the calling conventions for XCore architecture.
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// XCore Return Value Calling Convention
+//===----------------------------------------------------------------------===//
+def RetCC_XCore : CallingConv<[
+  // i32 are returned in registers R0, R1, R2, R3
+  CCIfType<[i32], CCAssignToReg<[R0, R1, R2, R3]>>
+]>;
+
+//===----------------------------------------------------------------------===//
+// XCore Argument Calling Conventions
+//===----------------------------------------------------------------------===//
+def CC_XCore : CallingConv<[
+  // Promote i8/i16 arguments to i32.
+  CCIfType<[i8, i16], CCPromoteToType<i32>>,
+
+  // The first 4 integer arguments are passed in integer registers.
+  CCIfType<[i32], CCAssignToReg<[R0, R1, R2, R3]>>,
+
+  // Integer values get stored in stack slots that are 4 bytes in
+  // size and 4-byte aligned.
+  CCIfType<[i32], CCAssignToStack<4, 4>>
+]>;