SPIRVCallLowering.h

//===--- SPIRVCallLowering.h - Call lowering --------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file describes how to lower LLVM calls to machine code calls.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_SPIRV_SPIRVCALLLOWERING_H
#define LLVM_LIB_TARGET_SPIRV_SPIRVCALLLOWERING_H

#include "SPIRVGlobalRegistry.h"
#include "llvm/CodeGen/GlobalISel/CallLowering.h"

namespace llvm {

class SPIRVGlobalRegistry;
class SPIRVTargetLowering;

class SPIRVCallLowering : public CallLowering {
private:
  // Used to create and assign function, argument, and return type information.
  SPIRVGlobalRegistry *GR;

  // Used to postpone producing of indirect function pointer types
  // after all indirect calls info is collected
  struct SPIRVIndirectCall {
    const Type *RetTy = nullptr;
    SmallVector<Type *> ArgTys;
    SmallVector<Register> ArgRegs;
    Register Callee;
  };
  void produceIndirectPtrTypes(MachineIRBuilder &MIRBuilder) const;
  mutable SmallVector<SPIRVIndirectCall> IndirectCalls;

public:
  SPIRVCallLowering(const SPIRVTargetLowering &TLI, SPIRVGlobalRegistry *GR);

  // Built OpReturn or OpReturnValue.
  bool lowerReturn(MachineIRBuilder &MIRBuiler, const Value *Val,
                   ArrayRef<Register> VRegs, FunctionLoweringInfo &FLI,
                   Register SwiftErrorVReg) const override;

  // Build OpFunction, OpFunctionParameter, and any EntryPoint or Linkage data.
  bool lowerFormalArguments(MachineIRBuilder &MIRBuilder, const Function &F,
                            ArrayRef<ArrayRef<Register>> VRegs,
                            FunctionLoweringInfo &FLI) const override;

  // Build OpCall, or replace with a builtin function.
  bool lowerCall(MachineIRBuilder &MIRBuilder,
                 CallLoweringInfo &Info) const override;
};
} // end namespace llvm

#endif // LLVM_LIB_TARGET_SPIRV_SPIRVCALLLOWERING_H