llvm-project/llvm/lib/Target/RISCV/RISCVSubtarget.h
lewis-revill 07f7c00208 [RISCV] Add support for save/restore of callee-saved registers via libcalls
This patch adds the support required for using the __riscv_save and
__riscv_restore libcalls to implement a size-optimization for prologue
and epilogue code, whereby the spill and restore code of callee-saved
registers is implemented by common functions to reduce code duplication.

Logic is also included to ensure that if both this optimization and
shrink wrapping are enabled then the prologue and epilogue code can be
safely inserted into the basic blocks chosen by shrink wrapping.

Differential Revision: https://reviews.llvm.org/D62686
2020-02-11 21:23:03 +00:00

120 lines
4.4 KiB
C++

//===-- RISCVSubtarget.h - Define Subtarget for the RISCV -------*- 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 declares the RISCV specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_RISCV_RISCVSUBTARGET_H
#define LLVM_LIB_TARGET_RISCV_RISCVSUBTARGET_H
#include "RISCVFrameLowering.h"
#include "RISCVISelLowering.h"
#include "RISCVInstrInfo.h"
#include "Utils/RISCVBaseInfo.h"
#include "llvm/CodeGen/GlobalISel/CallLowering.h"
#include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
#include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
#include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
#include "llvm/CodeGen/SelectionDAGTargetInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/Target/TargetMachine.h"
#define GET_SUBTARGETINFO_HEADER
#include "RISCVGenSubtargetInfo.inc"
namespace llvm {
class StringRef;
class RISCVSubtarget : public RISCVGenSubtargetInfo {
virtual void anchor();
bool HasStdExtM = false;
bool HasStdExtA = false;
bool HasStdExtF = false;
bool HasStdExtD = false;
bool HasStdExtC = false;
bool HasRV64 = false;
bool IsRV32E = false;
bool EnableLinkerRelax = false;
bool EnableRVCHintInstrs = false;
bool EnableSaveRestore = false;
unsigned XLen = 32;
MVT XLenVT = MVT::i32;
RISCVABI::ABI TargetABI = RISCVABI::ABI_Unknown;
BitVector UserReservedRegister;
RISCVFrameLowering FrameLowering;
RISCVInstrInfo InstrInfo;
RISCVRegisterInfo RegInfo;
RISCVTargetLowering TLInfo;
SelectionDAGTargetInfo TSInfo;
/// Initializes using the passed in CPU and feature strings so that we can
/// use initializer lists for subtarget initialization.
RISCVSubtarget &initializeSubtargetDependencies(const Triple &TT,
StringRef CPU, StringRef FS,
StringRef ABIName);
public:
// Initializes the data members to match that of the specified triple.
RISCVSubtarget(const Triple &TT, StringRef CPU, StringRef FS,
StringRef ABIName, const TargetMachine &TM);
// Parses features string setting specified subtarget options. The
// definition of this function is auto-generated by tblgen.
void ParseSubtargetFeatures(StringRef CPU, StringRef FS);
const RISCVFrameLowering *getFrameLowering() const override {
return &FrameLowering;
}
const RISCVInstrInfo *getInstrInfo() const override { return &InstrInfo; }
const RISCVRegisterInfo *getRegisterInfo() const override {
return &RegInfo;
}
const RISCVTargetLowering *getTargetLowering() const override {
return &TLInfo;
}
const SelectionDAGTargetInfo *getSelectionDAGInfo() const override {
return &TSInfo;
}
bool enableMachineScheduler() const override { return true; }
bool hasStdExtM() const { return HasStdExtM; }
bool hasStdExtA() const { return HasStdExtA; }
bool hasStdExtF() const { return HasStdExtF; }
bool hasStdExtD() const { return HasStdExtD; }
bool hasStdExtC() const { return HasStdExtC; }
bool is64Bit() const { return HasRV64; }
bool isRV32E() const { return IsRV32E; }
bool enableLinkerRelax() const { return EnableLinkerRelax; }
bool enableRVCHintInstrs() const { return EnableRVCHintInstrs; }
bool enableSaveRestore() const { return EnableSaveRestore; }
MVT getXLenVT() const { return XLenVT; }
unsigned getXLen() const { return XLen; }
RISCVABI::ABI getTargetABI() const { return TargetABI; }
bool isRegisterReservedByUser(Register i) const {
assert(i < RISCV::NUM_TARGET_REGS && "Register out of range");
return UserReservedRegister[i];
}
protected:
// GlobalISel related APIs.
std::unique_ptr<CallLowering> CallLoweringInfo;
std::unique_ptr<InstructionSelector> InstSelector;
std::unique_ptr<LegalizerInfo> Legalizer;
std::unique_ptr<RegisterBankInfo> RegBankInfo;
public:
const CallLowering *getCallLowering() const override;
InstructionSelector *getInstructionSelector() const override;
const LegalizerInfo *getLegalizerInfo() const override;
const RegisterBankInfo *getRegBankInfo() const override;
};
} // End llvm namespace
#endif