Home | History | Annotate | Line # | Download | only in M68k 
      1 //===-- M68kCallingConv.h - M68k Custom CC Routines ---------*- C++ -*-===//
      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 ///
      9 /// \file
     10 /// This file contains the custom routines for the M68k Calling Convention
     11 /// that aren't done by tablegen.
     12 ///
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_LIB_TARGET_M68K_M68KCALLINGCONV_H
     16 #define LLVM_LIB_TARGET_M68K_M68KCALLINGCONV_H
     17 
     18 #include "MCTargetDesc/M68kMCTargetDesc.h"
     19 
     20 #include "llvm/CodeGen/CallingConvLower.h"
     21 #include "llvm/IR/CallingConv.h"
     22 #include "llvm/IR/Function.h"
     23 
     24 namespace llvm {
     25 
     26 /// Custom state to propagate llvm type info to register CC assigner
     27 class M68kCCState : public CCState {
     28 public:
     29   const llvm::Function &F;
     30 
     31   M68kCCState(const llvm::Function &F, CallingConv::ID CC, bool IsVarArg,
     32               MachineFunction &MF, SmallVectorImpl<CCValAssign> &Locs,
     33               LLVMContext &C)
     34       : CCState(CC, IsVarArg, MF, Locs, C), F(F) {}
     35 };
     36 
     37 /// NOTE this function is used to select registers for formal arguments and call
     38 /// FIXME: Handling on pointer arguments is not complete
     39 inline bool CC_M68k_Any_AssignToReg(unsigned &ValNo, MVT &ValVT, MVT &LocVT,
     40                                     CCValAssign::LocInfo &LocInfo,
     41                                     ISD::ArgFlagsTy &ArgFlags, CCState &State) {
     42   M68kCCState CCInfo = static_cast<M68kCCState &>(State);
     43 
     44   static const MCPhysReg DataRegList[] = {M68k::D0, M68k::D1, M68k::A0,
     45                                           M68k::A1};
     46 
     47   // Address registers have %a register priority
     48   static const MCPhysReg AddrRegList[] = {
     49       M68k::A0,
     50       M68k::A1,
     51       M68k::D0,
     52       M68k::D1,
     53   };
     54 
     55   auto I = CCInfo.F.arg_begin();
     56   int No = ValNo;
     57   while (No > 0) {
     58     No -= I->getType()->isIntegerTy(64) ? 2 : 1;
     59     I++;
     60   }
     61 
     62   bool IsPtr = I != CCInfo.F.arg_end() && I->getType()->isPointerTy();
     63 
     64   unsigned Reg =
     65       IsPtr ? State.AllocateReg(AddrRegList) : State.AllocateReg(DataRegList);
     66 
     67   if (Reg) {
     68     State.addLoc(CCValAssign::getReg(ValNo, ValVT, Reg, LocVT, LocInfo));
     69     return true;
     70   }
     71 
     72   return false;
     73 }
     74 
     75 } // namespace llvm
     76 
     77 #endif
     78