xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AVR/AVRCallingConv.td (revision ec0ea6efa1ad229d75c394c1a9b9cac33af2b1d3)
1//===-- AVRCallingConv.td - Calling Conventions for AVR ----*- tablegen -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// This describes the calling conventions for AVR architecture.
9// Normal functions use a special calling convention, solved in code.
10//===----------------------------------------------------------------------===//
11
12//===----------------------------------------------------------------------===//
13// AVR Return Value Calling Convention
14//===----------------------------------------------------------------------===//
15
16// Special return value calling convention for runtime functions.
17def RetCC_AVR_BUILTIN : CallingConv
18<[
19  CCIfType<[i8], CCAssignToReg<[R24,R25]>>,
20  CCIfType<[i16], CCAssignToReg<[R23R22, R25R24]>>
21]>;
22
23//===----------------------------------------------------------------------===//
24// AVR Argument Calling Conventions
25//===----------------------------------------------------------------------===//
26
27// The calling conventions are implemented in custom C++ code
28
29// Calling convention for variadic functions.
30def ArgCC_AVR_Vararg : CallingConv
31<[
32  // i16 are always passed through the stack with an alignment of 1.
33  CCAssignToStack<2, 1>
34]>;
35
36//===----------------------------------------------------------------------===//
37// Callee-saved register lists.
38//===----------------------------------------------------------------------===//
39
40def CSR_Normal : CalleeSavedRegs<(add R29, R28, (sequence "R%u", 17, 2))>;
41def CSR_Interrupts : CalleeSavedRegs<(add (sequence "R%u", 31, 0))>;
42