llvm/llvm/lib/CodeGen/RegUsageInfoPropagate.cpp

//=--- RegUsageInfoPropagate.cpp - Register Usage Informartion Propagation --=//
//
// 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 pass is required to take advantage of the interprocedural register
/// allocation infrastructure.
///
/// This pass iterates through MachineInstrs in a given MachineFunction and at
/// each callsite queries RegisterUsageInfo for RegMask (calculated based on
/// actual register allocation) of the callee function, if the RegMask detail
/// is available then this pass will update the RegMask of the call instruction.
/// This updated RegMask will be used by the register allocator while allocating
/// the current MachineFunction.
///
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/RegisterUsageInfo.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"

usingnamespacellvm;

#define DEBUG_TYPE …

#define RUIP_NAME …

namespace {

class RegUsageInfoPropagation : public MachineFunctionPass { … };

} // end of anonymous namespace

INITIALIZE_PASS_BEGIN(RegUsageInfoPropagation, "reg-usage-propagation",
                      RUIP_NAME, false, false)
INITIALIZE_PASS_DEPENDENCY(PhysicalRegisterUsageInfo)
INITIALIZE_PASS_END(RegUsageInfoPropagation, "reg-usage-propagation",
                    RUIP_NAME, false, false)

char RegUsageInfoPropagation::ID = …;

// Assumes call instructions have a single reference to a function.
static const Function *findCalledFunction(const Module &M,
                                          const MachineInstr &MI) { … }

bool RegUsageInfoPropagation::runOnMachineFunction(MachineFunction &MF) { … }

FunctionPass *llvm::createRegUsageInfoPropPass() { … }