llvm/lib/Target/XCore/XCoreCallingConv.td

//===- XCoreCallingConv.td - Calling Conventions for XCore -*- tablegen -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
// 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]>>,

  // Integer values get stored in stack slots that are 4 bytes in
  // size and 4-byte aligned.
  CCIfType<[i32], CCAssignToStack<4, 4>>
]>;

//===----------------------------------------------------------------------===//
// XCore Argument Calling Conventions
//===----------------------------------------------------------------------===//
def CC_XCore : CallingConv<[
  // Promote i8/i16 arguments to i32.
  CCIfType<[i8, i16], CCPromoteToType<i32>>,

  // The 'nest' parameter, if any, is passed in R11.
  CCIfNest<CCAssignToReg<[R11]>>,

  // 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>>
]>;