[lanai] Add Lanai backend.

Add the Lanai backend to lib/Target.

General Lanai backend discussion on llvm-dev thread "[RFC] Lanai backend" (http://lists.llvm.org/pipermail/llvm-dev/2016-February/095118.html).

Differential Revision: http://reviews.llvm.org/D17011



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264578 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 50 insertions, 0 deletions

diff --git a/lib/Target/Lanai/LanaiCallingConv.td b/lib/Target/Lanai/LanaiCallingConv.td
new file mode 100644
index 00000000000..056b329c33c
--- /dev/null
+++ b/lib/Target/Lanai/LanaiCallingConv.td
@@ -0,0 +1,50 @@
+//===- LanaiCallingConv.td - Calling Conventions Lanai -------*- 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 the Lanai architectures.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Return Value Calling Conventions
+//===----------------------------------------------------------------------===//
+
+// Lanai 32-bit C Calling convention.
+def CC_Lanai32 : CallingConv<[
+  // Promote i8/i16 args to i32
+  CCIfType<[i8, i16], CCPromoteToType<i32>>,
+
+  // Put argument in registers if marked 'inreg' and not a vararg call.
+  CCIfNotVarArg<CCIfInReg<CCIfType<[i32],
+                                   CCAssignToReg<[R6, R7, R18, R19]>>>>,
+
+  // Otherwise they are assigned to the stack in 4-byte aligned units.
+  CCAssignToStack<4, 4>
+]>;
+
+// Lanai 32-bit Fast Calling convention.
+def CC_Lanai32_Fast : CallingConv<[
+  // Promote i8/i16 args to i32
+  CCIfType<[ i8, i16 ], CCPromoteToType<i32>>,
+
+  // Put arguments in registers.
+  CCIfNotVarArg<CCIfType<[i32], CCAssignToReg<[ R6, R7, R18, R19 ]>>>,
+
+  // Otherwise they are assigned to the stack in 4-byte aligned units.
+  CCAssignToStack<4, 4>
+]>;
+
+// Lanai 32-bit C return-value convention.
+def RetCC_Lanai32 : CallingConv<[
+  // Specify two registers to allow returning 64-bit results that have already
+  // been lowered to 2 32-bit values.
+  CCIfType<[i32], CCAssignToReg<[RV, R9]>>
+]>;
+
+def CSR: CalleeSavedRegs<(add)>;