Files
clang-p2996/llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCTargetDesc.cpp
ZhaoQi 1c68c4c57a [LoongArch][MC] Modify branch evaluation for MCInstrAnalysis (#73205)
Function evaluateBranch() is used to compute target address for a given
branch instruction and return true on success. But target address of
indirect branch cannot be simply added, so rule it out and just return
false.

This patch also add objdump tests which capture the current state of
support for printing branch targets. Without this patch, the result of
"jirl $zero, $a0, 4" is "jirl $zero, $a0, 4 <foo+0x64>". It is obviously
incorrect, because this instruction represents an indirect branch whose
target address depends on both the register value and the imm. After
this patch, it will be right despite loss of details.
2023-11-23 16:38:41 +08:00

218 lines
7.1 KiB
C++

//===-- LoongArchMCTargetDesc.cpp - LoongArch Target Descriptions ---------===//
//
// 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 provides LoongArch specific target descriptions.
//
//===----------------------------------------------------------------------===//
#include "LoongArchMCTargetDesc.h"
#include "LoongArchBaseInfo.h"
#include "LoongArchELFStreamer.h"
#include "LoongArchInstPrinter.h"
#include "LoongArchMCAsmInfo.h"
#include "TargetInfo/LoongArchTargetInfo.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCDwarf.h"
#include "llvm/MC/MCInstrAnalysis.h"
#include "llvm/MC/MCInstrInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCSubtargetInfo.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/Compiler.h"
#define GET_INSTRINFO_MC_DESC
#define ENABLE_INSTR_PREDICATE_VERIFIER
#include "LoongArchGenInstrInfo.inc"
#define GET_REGINFO_MC_DESC
#include "LoongArchGenRegisterInfo.inc"
#define GET_SUBTARGETINFO_MC_DESC
#include "LoongArchGenSubtargetInfo.inc"
using namespace llvm;
static MCRegisterInfo *createLoongArchMCRegisterInfo(const Triple &TT) {
MCRegisterInfo *X = new MCRegisterInfo();
InitLoongArchMCRegisterInfo(X, LoongArch::R1);
return X;
}
static MCInstrInfo *createLoongArchMCInstrInfo() {
MCInstrInfo *X = new MCInstrInfo();
InitLoongArchMCInstrInfo(X);
return X;
}
static MCSubtargetInfo *
createLoongArchMCSubtargetInfo(const Triple &TT, StringRef CPU, StringRef FS) {
if (CPU.empty() || CPU == "generic")
CPU = TT.isArch64Bit() ? "la464" : "generic-la32";
return createLoongArchMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS);
}
static MCAsmInfo *createLoongArchMCAsmInfo(const MCRegisterInfo &MRI,
const Triple &TT,
const MCTargetOptions &Options) {
MCAsmInfo *MAI = new LoongArchMCAsmInfo(TT);
// Initial state of the frame pointer is sp(r3).
MCRegister SP = MRI.getDwarfRegNum(LoongArch::R3, true);
MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(nullptr, SP, 0);
MAI->addInitialFrameState(Inst);
return MAI;
}
static MCInstPrinter *createLoongArchMCInstPrinter(const Triple &T,
unsigned SyntaxVariant,
const MCAsmInfo &MAI,
const MCInstrInfo &MII,
const MCRegisterInfo &MRI) {
return new LoongArchInstPrinter(MAI, MII, MRI);
}
static MCTargetStreamer *
createLoongArchObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
return STI.getTargetTriple().isOSBinFormatELF()
? new LoongArchTargetELFStreamer(S, STI)
: nullptr;
}
namespace {
class LoongArchMCInstrAnalysis : public MCInstrAnalysis {
public:
explicit LoongArchMCInstrAnalysis(const MCInstrInfo *Info)
: MCInstrAnalysis(Info) {}
bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size,
uint64_t &Target) const override {
unsigned NumOps = Inst.getNumOperands();
if ((isBranch(Inst) && !isIndirectBranch(Inst)) ||
Inst.getOpcode() == LoongArch::BL) {
Target = Addr + Inst.getOperand(NumOps - 1).getImm();
return true;
}
return false;
}
bool isTerminator(const MCInst &Inst) const override {
if (MCInstrAnalysis::isTerminator(Inst))
return true;
switch (Inst.getOpcode()) {
default:
return false;
case LoongArch::JIRL:
return Inst.getOperand(0).getReg() == LoongArch::R0;
}
}
bool isCall(const MCInst &Inst) const override {
if (MCInstrAnalysis::isCall(Inst))
return true;
switch (Inst.getOpcode()) {
default:
return false;
case LoongArch::JIRL:
return Inst.getOperand(0).getReg() != LoongArch::R0;
}
}
bool isReturn(const MCInst &Inst) const override {
if (MCInstrAnalysis::isReturn(Inst))
return true;
switch (Inst.getOpcode()) {
default:
return false;
case LoongArch::JIRL:
return Inst.getOperand(0).getReg() == LoongArch::R0 &&
Inst.getOperand(1).getReg() == LoongArch::R1;
}
}
bool isBranch(const MCInst &Inst) const override {
if (MCInstrAnalysis::isBranch(Inst))
return true;
switch (Inst.getOpcode()) {
default:
return false;
case LoongArch::JIRL:
return Inst.getOperand(0).getReg() == LoongArch::R0 &&
Inst.getOperand(1).getReg() != LoongArch::R1;
}
}
bool isUnconditionalBranch(const MCInst &Inst) const override {
if (MCInstrAnalysis::isUnconditionalBranch(Inst))
return true;
switch (Inst.getOpcode()) {
default:
return false;
case LoongArch::JIRL:
return Inst.getOperand(0).getReg() == LoongArch::R0 &&
Inst.getOperand(1).getReg() != LoongArch::R1;
}
}
bool isIndirectBranch(const MCInst &Inst) const override {
if (MCInstrAnalysis::isIndirectBranch(Inst))
return true;
switch (Inst.getOpcode()) {
default:
return false;
case LoongArch::JIRL:
return Inst.getOperand(0).getReg() == LoongArch::R0 &&
Inst.getOperand(1).getReg() != LoongArch::R1;
}
}
};
} // end namespace
static MCInstrAnalysis *createLoongArchInstrAnalysis(const MCInstrInfo *Info) {
return new LoongArchMCInstrAnalysis(Info);
}
namespace {
MCStreamer *createLoongArchELFStreamer(const Triple &T, MCContext &Context,
std::unique_ptr<MCAsmBackend> &&MAB,
std::unique_ptr<MCObjectWriter> &&MOW,
std::unique_ptr<MCCodeEmitter> &&MCE,
bool RelaxAll) {
return createLoongArchELFStreamer(Context, std::move(MAB), std::move(MOW),
std::move(MCE), RelaxAll);
}
} // end namespace
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeLoongArchTargetMC() {
for (Target *T : {&getTheLoongArch32Target(), &getTheLoongArch64Target()}) {
TargetRegistry::RegisterMCRegInfo(*T, createLoongArchMCRegisterInfo);
TargetRegistry::RegisterMCInstrInfo(*T, createLoongArchMCInstrInfo);
TargetRegistry::RegisterMCSubtargetInfo(*T, createLoongArchMCSubtargetInfo);
TargetRegistry::RegisterMCAsmInfo(*T, createLoongArchMCAsmInfo);
TargetRegistry::RegisterMCCodeEmitter(*T, createLoongArchMCCodeEmitter);
TargetRegistry::RegisterMCAsmBackend(*T, createLoongArchAsmBackend);
TargetRegistry::RegisterMCInstPrinter(*T, createLoongArchMCInstPrinter);
TargetRegistry::RegisterMCInstrAnalysis(*T, createLoongArchInstrAnalysis);
TargetRegistry::RegisterELFStreamer(*T, createLoongArchELFStreamer);
TargetRegistry::RegisterObjectTargetStreamer(
*T, createLoongArchObjectTargetStreamer);
}
}