llvm/llvm/lib/Target/SystemZ/SystemZTargetMachine.cpp

//===-- SystemZTargetMachine.cpp - Define TargetMachine for SystemZ -------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "SystemZTargetMachine.h"
#include "MCTargetDesc/SystemZMCTargetDesc.h"
#include "SystemZ.h"
#include "SystemZMachineFunctionInfo.h"
#include "SystemZMachineScheduler.h"
#include "SystemZTargetObjectFile.h"
#include "SystemZTargetTransformInfo.h"
#include "TargetInfo/SystemZTargetInfo.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Transforms/Scalar.h"
#include <memory>
#include <optional>
#include <string>

usingnamespacellvm;

static cl::opt<bool> EnableMachineCombinerPass(
    "systemz-machine-combiner",
    cl::desc("Enable the machine combiner pass"),
    cl::init(true), cl::Hidden);

// NOLINTNEXTLINE(readability-identifier-naming)
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeSystemZTarget() { … }

static std::string computeDataLayout(const Triple &TT) { … }

static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) { … }

static Reloc::Model getEffectiveRelocModel(std::optional<Reloc::Model> RM) { … }

// For SystemZ we define the models as follows:
//
// Small:  BRASL can call any function and will use a stub if necessary.
//         Locally-binding symbols will always be in range of LARL.
//
// Medium: BRASL can call any function and will use a stub if necessary.
//         GOT slots and locally-defined text will always be in range
//         of LARL, but other symbols might not be.
//
// Large:  Equivalent to Medium for now.
//
// Kernel: Equivalent to Medium for now.
//
// This means that any PIC module smaller than 4GB meets the
// requirements of Small, so Small seems like the best default there.
//
// All symbols bind locally in a non-PIC module, so the choice is less
// obvious.  There are two cases:
//
// - When creating an executable, PLTs and copy relocations allow
//   us to treat external symbols as part of the executable.
//   Any executable smaller than 4GB meets the requirements of Small,
//   so that seems like the best default.
//
// - When creating JIT code, stubs will be in range of BRASL if the
//   image is less than 4GB in size.  GOT entries will likewise be
//   in range of LARL.  However, the JIT environment has no equivalent
//   of copy relocs, so locally-binding data symbols might not be in
//   the range of LARL.  We need the Medium model in that case.
static CodeModel::Model
getEffectiveSystemZCodeModel(std::optional<CodeModel::Model> CM,
                             Reloc::Model RM, bool JIT) { … }

SystemZTargetMachine::SystemZTargetMachine(const Target &T, const Triple &TT,
                                           StringRef CPU, StringRef FS,
                                           const TargetOptions &Options,
                                           std::optional<Reloc::Model> RM,
                                           std::optional<CodeModel::Model> CM,
                                           CodeGenOptLevel OL, bool JIT)
    : … { … }

SystemZTargetMachine::~SystemZTargetMachine() = default;

const SystemZSubtarget *
SystemZTargetMachine::getSubtargetImpl(const Function &F) const { … }

namespace {

/// SystemZ Code Generator Pass Configuration Options.
class SystemZPassConfig : public TargetPassConfig { … };

} // end anonymous namespace

void SystemZPassConfig::addIRPasses() { … }

bool SystemZPassConfig::addInstSelector() { … }

bool SystemZPassConfig::addILPOpts() { … }

void SystemZPassConfig::addPreRegAlloc() { … }

void SystemZPassConfig::addPostRewrite() { … }

void SystemZPassConfig::addPostRegAlloc() { … }

void SystemZPassConfig::addPreSched2() { … }

void SystemZPassConfig::addPreEmitPass() { … }

TargetPassConfig *SystemZTargetMachine::createPassConfig(PassManagerBase &PM) { … }

TargetTransformInfo
SystemZTargetMachine::getTargetTransformInfo(const Function &F) const { … }

MachineFunctionInfo *SystemZTargetMachine::createMachineFunctionInfo(
    BumpPtrAllocator &Allocator, const Function &F,
    const TargetSubtargetInfo *STI) const { … }