llvm-6502/lib/Target/XCore/XCoreCallingConv.td
Richard Osborne cc331c8f40 [XCore] Support functions returning more than 4 words.
If a function returns a large struct by value return the first 4 words
in registers and the rest on the stack in a location reserved by the
caller. This is needed to support the xC language which supports
functions returning an arbitrary number of return values. This is
r202397 reapplied with a fix to avoid an uninitialized read of a member.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202414 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-27 17:47:54 +00:00

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TableGen

//===- 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]>>,
// 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>>
]>;