mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-30 21:29:28 +00:00
MSVC always places the 'this' parameter for a method first. The implicit 'sret' pointer for methods always comes second. We already implement this for __thiscall by putting sret parameters on the stack, but __cdecl methods require putting both parameters on the stack in opposite order. Using a special calling convention allows frontends to keep the sret parameter first, which avoids breaking lots of assumptions in LLVM and Clang. Fixes PR15768 with the corresponding change in Clang. Reviewers: ributzka, majnemer Differential Revision: http://llvm-reviews.chandlerc.com/D2663 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200561 91177308-0d34-0410-b5e6-96231b3b80d8
63 lines
2.2 KiB
C++
63 lines
2.2 KiB
C++
//=== X86CallingConv.h - X86 Custom Calling Convention Routines -*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file contains the custom routines for the X86 Calling Convention that
|
|
// aren't done by tablegen.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef X86CALLINGCONV_H
|
|
#define X86CALLINGCONV_H
|
|
|
|
#include "llvm/CodeGen/CallingConvLower.h"
|
|
#include "llvm/IR/CallingConv.h"
|
|
|
|
namespace llvm {
|
|
|
|
inline bool CC_X86_AnyReg_Error(unsigned &, MVT &, MVT &,
|
|
CCValAssign::LocInfo &, ISD::ArgFlagsTy &,
|
|
CCState &) {
|
|
llvm_unreachable("The AnyReg calling convention is only supported by the " \
|
|
"stackmap and patchpoint intrinsics.");
|
|
// gracefully fallback to X86 C calling convention on Release builds.
|
|
return false;
|
|
}
|
|
|
|
inline bool CC_X86_CDeclMethod_SRet(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
|
|
CCValAssign::LocInfo &LocInfo,
|
|
ISD::ArgFlagsTy &ArgFlags, CCState &State) {
|
|
// Swap the order of the first two parameters if the first parameter is sret.
|
|
if (ArgFlags.isSRet()) {
|
|
assert(ValNo == 0);
|
|
assert(ValVT == MVT::i32);
|
|
State.AllocateStack(8, 4);
|
|
State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT, 4, LocVT, LocInfo));
|
|
|
|
// Indicate that we need to swap the order of the first and second
|
|
// parameters by "allocating" register zero. There are no register
|
|
// parameters with cdecl methods, so we can use this to communicate to the
|
|
// next call.
|
|
State.AllocateReg(1);
|
|
return true;
|
|
} else if (ValNo == 1 && State.isAllocated(1)) {
|
|
assert(ValVT == MVT::i32 && "non-i32-sized this param unsupported");
|
|
// Stack was already allocated while processing sret.
|
|
State.addLoc(CCValAssign::getCustomMem(ValNo, ValVT, 0, LocVT, LocInfo));
|
|
return true;
|
|
}
|
|
|
|
// All other args use the C calling convention.
|
|
return false;
|
|
}
|
|
|
|
} // End llvm namespace
|
|
|
|
#endif
|
|
|