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//===-- PPCCallLowering.h - Call lowering for GlobalISel -------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements the lowering of LLVM calls to machine code calls for
/// GlobalISel.
///
//===----------------------------------------------------------------------===//
#include "PPCCallLowering.h"
#include "PPCCallingConv.h"
#include "PPCISelLowering.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "llvm/CodeGen/CallingConvLower.h"
#include "llvm/CodeGen/GlobalISel/CallLowering.h"
#include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/TargetCallingConv.h"
#include "llvm/Support/Debug.h"
#define DEBUG_TYPE "ppc-call-lowering"
using namespace llvm;
namespace {
struct OutgoingArgHandler : public CallLowering::OutgoingValueHandler {
OutgoingArgHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
MachineInstrBuilder MIB)
: OutgoingValueHandler(MIRBuilder, MRI), MIB(MIB) {}
void assignValueToReg(Register ValVReg, Register PhysReg,
CCValAssign VA) override;
void assignValueToAddress(Register ValVReg, Register Addr, LLT MemTy,
MachinePointerInfo &MPO, CCValAssign &VA) override;
Register getStackAddress(uint64_t Size, int64_t Offset,
MachinePointerInfo &MPO,
ISD::ArgFlagsTy Flags) override;
MachineInstrBuilder MIB;
};
} // namespace
void OutgoingArgHandler::assignValueToReg(Register ValVReg, Register PhysReg,
CCValAssign VA) {
MIB.addUse(PhysReg, RegState::Implicit);
Register ExtReg = extendRegister(ValVReg, VA);
MIRBuilder.buildCopy(PhysReg, ExtReg);
}
void OutgoingArgHandler::assignValueToAddress(Register ValVReg, Register Addr,
LLT MemTy,
MachinePointerInfo &MPO,
CCValAssign &VA) {
llvm_unreachable("unimplemented");
}
Register OutgoingArgHandler::getStackAddress(uint64_t Size, int64_t Offset,
MachinePointerInfo &MPO,
ISD::ArgFlagsTy Flags) {
llvm_unreachable("unimplemented");
}
PPCCallLowering::PPCCallLowering(const PPCTargetLowering &TLI)
: CallLowering(&TLI) {}
bool PPCCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
const Value *Val, ArrayRef<Register> VRegs,
FunctionLoweringInfo &FLI,
Register SwiftErrorVReg) const {
auto MIB = MIRBuilder.buildInstrNoInsert(PPC::BLR8);
bool Success = true;
MachineFunction &MF = MIRBuilder.getMF();
const Function &F = MF.getFunction();
MachineRegisterInfo &MRI = MF.getRegInfo();
auto &DL = F.getParent()->getDataLayout();
if (!VRegs.empty()) {
// Setup the information about the return value.
ArgInfo OrigArg{VRegs, Val->getType(), 0};
setArgFlags(OrigArg, AttributeList::ReturnIndex, DL, F);
// Split the return value into consecutive registers if needed.
SmallVector<ArgInfo, 8> SplitArgs;
splitToValueTypes(OrigArg, SplitArgs, DL, F.getCallingConv());
// Use the calling convention callback to determine type and location of
// return value.
OutgoingValueAssigner ArgAssigner(RetCC_PPC);
// Handler to move the return value into the correct location.
OutgoingArgHandler ArgHandler(MIRBuilder, MRI, MIB);
// Iterate over all return values, and move them to the assigned location.
Success = determineAndHandleAssignments(ArgHandler, ArgAssigner, SplitArgs,
MIRBuilder, F.getCallingConv(),
F.isVarArg());
}
MIRBuilder.insertInstr(MIB);
return Success;
}
bool PPCCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
CallLoweringInfo &Info) const {
return false;
}
bool PPCCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
const Function &F,
ArrayRef<ArrayRef<Register>> VRegs,
FunctionLoweringInfo &FLI) const {
MachineFunction &MF = MIRBuilder.getMF();
MachineRegisterInfo &MRI = MF.getRegInfo();
const auto &DL = F.getParent()->getDataLayout();
auto &TLI = *getTLI<PPCTargetLowering>();
// Loop over each arg, set flags and split to single value types
SmallVector<ArgInfo, 8> SplitArgs;
unsigned I = 0;
for (const auto &Arg : F.args()) {
if (DL.getTypeStoreSize(Arg.getType()).isZero())
continue;
ArgInfo OrigArg{VRegs[I], Arg, I};
setArgFlags(OrigArg, I + AttributeList::FirstArgIndex, DL, F);
splitToValueTypes(OrigArg, SplitArgs, DL, F.getCallingConv());
++I;
}
CCAssignFn *AssignFn =
TLI.ccAssignFnForCall(F.getCallingConv(), false, F.isVarArg());
IncomingValueAssigner ArgAssigner(AssignFn);
FormalArgHandler ArgHandler(MIRBuilder, MRI);
return determineAndHandleAssignments(ArgHandler, ArgAssigner, SplitArgs,
MIRBuilder, F.getCallingConv(),
F.isVarArg());
}
void PPCIncomingValueHandler::assignValueToReg(Register ValVReg,
Register PhysReg,
CCValAssign VA) {
markPhysRegUsed(PhysReg);
IncomingValueHandler::assignValueToReg(ValVReg, PhysReg, VA);
}
void PPCIncomingValueHandler::assignValueToAddress(Register ValVReg,
Register Addr, LLT MemTy,
MachinePointerInfo &MPO,
CCValAssign &VA) {
// define a lambda expression to load value
auto BuildLoad = [](MachineIRBuilder &MIRBuilder, MachinePointerInfo &MPO,
LLT MemTy, const DstOp &Res, Register Addr) {
MachineFunction &MF = MIRBuilder.getMF();
auto *MMO = MF.getMachineMemOperand(MPO, MachineMemOperand::MOLoad, MemTy,
inferAlignFromPtrInfo(MF, MPO));
return MIRBuilder.buildLoad(Res, Addr, *MMO);
};
BuildLoad(MIRBuilder, MPO, MemTy, ValVReg, Addr);
}
Register PPCIncomingValueHandler::getStackAddress(uint64_t Size, int64_t Offset,
MachinePointerInfo &MPO,
ISD::ArgFlagsTy Flags) {
auto &MFI = MIRBuilder.getMF().getFrameInfo();
const bool IsImmutable = !Flags.isByVal();
int FI = MFI.CreateFixedObject(Size, Offset, IsImmutable);
MPO = MachinePointerInfo::getFixedStack(MIRBuilder.getMF(), FI);
// Build Frame Index based on whether the machine is 32-bit or 64-bit
llvm::LLT FramePtr = LLT::pointer(
0, MIRBuilder.getMF().getDataLayout().getPointerSizeInBits());
MachineInstrBuilder AddrReg = MIRBuilder.buildFrameIndex(FramePtr, FI);
StackUsed = std::max(StackUsed, Size + Offset);
return AddrReg.getReg(0);
}
void FormalArgHandler::markPhysRegUsed(unsigned PhysReg) {
MIRBuilder.getMRI()->addLiveIn(PhysReg);
MIRBuilder.getMBB().addLiveIn(PhysReg);
}
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