//===- MipsAsmPrinter.cpp - Mips LLVM Assembly Printer --------------------===// // // 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 contains a printer that converts from our internal representation // of machine-dependent LLVM code to GAS-format MIPS assembly language. // //===----------------------------------------------------------------------===// #include "MipsAsmPrinter.h" #include "MCTargetDesc/MipsABIInfo.h" #include "MCTargetDesc/MipsBaseInfo.h" #include "MCTargetDesc/MipsInstPrinter.h" #include "MCTargetDesc/MipsMCNaCl.h" #include "MCTargetDesc/MipsMCTargetDesc.h" #include "Mips.h" #include "MipsMCInstLower.h" #include "MipsMachineFunction.h" #include "MipsSubtarget.h" #include "MipsTargetMachine.h" #include "MipsTargetStreamer.h" #include "TargetInfo/MipsTargetInfo.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringRef.h" #include "llvm/ADT/Triple.h" #include "llvm/ADT/Twine.h" #include "llvm/BinaryFormat/ELF.h" #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineConstantPool.h" #include "llvm/CodeGen/MachineFrameInfo.h" #include "llvm/CodeGen/MachineFunction.h" #include "llvm/CodeGen/MachineInstr.h" #include "llvm/CodeGen/MachineJumpTableInfo.h" #include "llvm/CodeGen/MachineOperand.h" #include "llvm/CodeGen/TargetRegisterInfo.h" #include "llvm/CodeGen/TargetSubtargetInfo.h" #include "llvm/IR/Attributes.h" #include "llvm/IR/BasicBlock.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/Function.h" #include "llvm/IR/InlineAsm.h" #include "llvm/IR/Instructions.h" #include "llvm/MC/MCContext.h" #include "llvm/MC/MCExpr.h" #include "llvm/MC/MCInst.h" #include "llvm/MC/MCInstBuilder.h" #include "llvm/MC/MCObjectFileInfo.h" #include "llvm/MC/MCSectionELF.h" #include "llvm/MC/MCSymbol.h" #include "llvm/MC/MCSymbolELF.h" #include "llvm/MC/TargetRegistry.h" #include "llvm/Support/Casting.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetLoweringObjectFile.h" #include "llvm/Target/TargetMachine.h" #include #include #include #include #include #include using namespace llvm; #define DEBUG_TYPE "mips-asm-printer" extern cl::opt EmitJalrReloc; MipsTargetStreamer &MipsAsmPrinter::getTargetStreamer() const { return static_cast(*OutStreamer->getTargetStreamer()); } bool MipsAsmPrinter::runOnMachineFunction(MachineFunction &MF) { Subtarget = &MF.getSubtarget(); MipsFI = MF.getInfo(); if (Subtarget->inMips16Mode()) for (const auto &I : MipsFI->StubsNeeded) { const char *Symbol = I.first; const Mips16HardFloatInfo::FuncSignature *Signature = I.second; if (StubsNeeded.find(Symbol) == StubsNeeded.end()) StubsNeeded[Symbol] = Signature; } MCP = MF.getConstantPool(); // In NaCl, all indirect jump targets must be aligned to bundle size. if (Subtarget->isTargetNaCl()) NaClAlignIndirectJumpTargets(MF); AsmPrinter::runOnMachineFunction(MF); emitXRayTable(); return true; } bool MipsAsmPrinter::lowerOperand(const MachineOperand &MO, MCOperand &MCOp) { MCOp = MCInstLowering.LowerOperand(MO); return MCOp.isValid(); } #include "MipsGenMCPseudoLowering.inc" // Lower PseudoReturn/PseudoIndirectBranch/PseudoIndirectBranch64 to JR, JR_MM, // JALR, or JALR64 as appropriate for the target. void MipsAsmPrinter::emitPseudoIndirectBranch(MCStreamer &OutStreamer, const MachineInstr *MI) { bool HasLinkReg = false; bool InMicroMipsMode = Subtarget->inMicroMipsMode(); MCInst TmpInst0; if (Subtarget->hasMips64r6()) { // MIPS64r6 should use (JALR64 ZERO_64, $rs) TmpInst0.setOpcode(Mips::JALR64); HasLinkReg = true; } else if (Subtarget->hasMips32r6()) { // MIPS32r6 should use (JALR ZERO, $rs) if (InMicroMipsMode) TmpInst0.setOpcode(Mips::JRC16_MMR6); else { TmpInst0.setOpcode(Mips::JALR); HasLinkReg = true; } } else if (Subtarget->inMicroMipsMode()) // microMIPS should use (JR_MM $rs) TmpInst0.setOpcode(Mips::JR_MM); else { // Everything else should use (JR $rs) TmpInst0.setOpcode(Mips::JR); } MCOperand MCOp; if (HasLinkReg) { unsigned ZeroReg = Subtarget->isGP64bit() ? Mips::ZERO_64 : Mips::ZERO; TmpInst0.addOperand(MCOperand::createReg(ZeroReg)); } lowerOperand(MI->getOperand(0), MCOp); TmpInst0.addOperand(MCOp); EmitToStreamer(OutStreamer, TmpInst0); } // If there is an MO_JALR operand, insert: // // .reloc tmplabel, R_{MICRO}MIPS_JALR, symbol // tmplabel: // // This is an optimization hint for the linker which may then replace // an indirect call with a direct branch. static void emitDirectiveRelocJalr(const MachineInstr &MI, MCContext &OutContext, TargetMachine &TM, MCStreamer &OutStreamer, const MipsSubtarget &Subtarget) { for (const MachineOperand &MO : llvm::drop_begin(MI.operands(), MI.getDesc().getNumOperands())) { if (MO.isMCSymbol() && (MO.getTargetFlags() & MipsII::MO_JALR)) { MCSymbol *Callee = MO.getMCSymbol(); if (Callee && !Callee->getName().empty()) { MCSymbol *OffsetLabel = OutContext.createTempSymbol(); const MCExpr *OffsetExpr = MCSymbolRefExpr::create(OffsetLabel, OutContext); const MCExpr *CaleeExpr = MCSymbolRefExpr::create(Callee, OutContext); OutStreamer.emitRelocDirective( *OffsetExpr, Subtarget.inMicroMipsMode() ? "R_MICROMIPS_JALR" : "R_MIPS_JALR", CaleeExpr, SMLoc(), *TM.getMCSubtargetInfo()); OutStreamer.emitLabel(OffsetLabel); return; } } } } void MipsAsmPrinter::emitInstruction(const MachineInstr *MI) { // FIXME: Enable feature predicate checks once all the test pass. // Mips_MC::verifyInstructionPredicates(MI->getOpcode(), // getSubtargetInfo().getFeatureBits()); MipsTargetStreamer &TS = getTargetStreamer(); unsigned Opc = MI->getOpcode(); TS.forbidModuleDirective(); if (MI->isDebugValue()) { SmallString<128> Str; raw_svector_ostream OS(Str); PrintDebugValueComment(MI, OS); return; } if (MI->isDebugLabel()) return; // If we just ended a constant pool, mark it as such. if (InConstantPool && Opc != Mips::CONSTPOOL_ENTRY) { OutStreamer->emitDataRegion(MCDR_DataRegionEnd); InConstantPool = false; } if (Opc == Mips::CONSTPOOL_ENTRY) { // CONSTPOOL_ENTRY - This instruction represents a floating // constant pool in the function. The first operand is the ID# // for this instruction, the second is the index into the // MachineConstantPool that this is, the third is the size in // bytes of this constant pool entry. // The required alignment is specified on the basic block holding this MI. // unsigned LabelId = (unsigned)MI->getOperand(0).getImm(); unsigned CPIdx = (unsigned)MI->getOperand(1).getIndex(); // If this is the first entry of the pool, mark it. if (!InConstantPool) { OutStreamer->emitDataRegion(MCDR_DataRegion); InConstantPool = true; } OutStreamer->emitLabel(GetCPISymbol(LabelId)); const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPIdx]; if (MCPE.isMachineConstantPoolEntry()) emitMachineConstantPoolValue(MCPE.Val.MachineCPVal); else emitGlobalConstant(MF->getDataLayout(), MCPE.Val.ConstVal); return; } switch (Opc) { case Mips::PATCHABLE_FUNCTION_ENTER: LowerPATCHABLE_FUNCTION_ENTER(*MI); return; case Mips::PATCHABLE_FUNCTION_EXIT: LowerPATCHABLE_FUNCTION_EXIT(*MI); return; case Mips::PATCHABLE_TAIL_CALL: LowerPATCHABLE_TAIL_CALL(*MI); return; } if (EmitJalrReloc && (MI->isReturn() || MI->isCall() || MI->isIndirectBranch())) { emitDirectiveRelocJalr(*MI, OutContext, TM, *OutStreamer, *Subtarget); } MachineBasicBlock::const_instr_iterator I = MI->getIterator(); MachineBasicBlock::const_instr_iterator E = MI->getParent()->instr_end(); do { // Do any auto-generated pseudo lowerings. if (emitPseudoExpansionLowering(*OutStreamer, &*I)) continue; // Skip the BUNDLE pseudo instruction and lower the contents if (I->isBundle()) continue; if (I->getOpcode() == Mips::PseudoReturn || I->getOpcode() == Mips::PseudoReturn64 || I->getOpcode() == Mips::PseudoIndirectBranch || I->getOpcode() == Mips::PseudoIndirectBranch64 || I->getOpcode() == Mips::TAILCALLREG || I->getOpcode() == Mips::TAILCALLREG64) { emitPseudoIndirectBranch(*OutStreamer, &*I); continue; } // The inMips16Mode() test is not permanent. // Some instructions are marked as pseudo right now which // would make the test fail for the wrong reason but // that will be fixed soon. We need this here because we are // removing another test for this situation downstream in the // callchain. // if (I->isPseudo() && !Subtarget->inMips16Mode() && !isLongBranchPseudo(I->getOpcode())) llvm_unreachable("Pseudo opcode found in emitInstruction()"); MCInst TmpInst0; MCInstLowering.Lower(&*I, TmpInst0); EmitToStreamer(*OutStreamer, TmpInst0); } while ((++I != E) && I->isInsideBundle()); // Delay slot check } //===----------------------------------------------------------------------===// // // Mips Asm Directives // // -- Frame directive "frame Stackpointer, Stacksize, RARegister" // Describe the stack frame. // // -- Mask directives "(f)mask bitmask, offset" // Tells the assembler which registers are saved and where. // bitmask - contain a little endian bitset indicating which registers are // saved on function prologue (e.g. with a 0x80000000 mask, the // assembler knows the register 31 (RA) is saved at prologue. // offset - the position before stack pointer subtraction indicating where // the first saved register on prologue is located. (e.g. with a // // Consider the following function prologue: // // .frame $fp,48,$ra // .mask 0xc0000000,-8 // addiu $sp, $sp, -48 // sw $ra, 40($sp) // sw $fp, 36($sp) // // With a 0xc0000000 mask, the assembler knows the register 31 (RA) and // 30 (FP) are saved at prologue. As the save order on prologue is from // left to right, RA is saved first. A -8 offset means that after the // stack pointer subtration, the first register in the mask (RA) will be // saved at address 48-8=40. // //===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===// // Mask directives //===----------------------------------------------------------------------===// // Create a bitmask with all callee saved registers for CPU or Floating Point // registers. For CPU registers consider RA, GP and FP for saving if necessary. void MipsAsmPrinter::printSavedRegsBitmask() { // CPU and FPU Saved Registers Bitmasks unsigned CPUBitmask = 0, FPUBitmask = 0; int CPUTopSavedRegOff, FPUTopSavedRegOff; // Set the CPU and FPU Bitmasks const MachineFrameInfo &MFI = MF->getFrameInfo(); const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo(); const std::vector &CSI = MFI.getCalleeSavedInfo(); // size of stack area to which FP callee-saved regs are saved. unsigned CPURegSize = TRI->getRegSizeInBits(Mips::GPR32RegClass) / 8; unsigned FGR32RegSize = TRI->getRegSizeInBits(Mips::FGR32RegClass) / 8; unsigned AFGR64RegSize = TRI->getRegSizeInBits(Mips::AFGR64RegClass) / 8; bool HasAFGR64Reg = false; unsigned CSFPRegsSize = 0; for (const auto &I : CSI) { Register Reg = I.getReg(); unsigned RegNum = TRI->getEncodingValue(Reg); // If it's a floating point register, set the FPU Bitmask. // If it's a general purpose register, set the CPU Bitmask. if (Mips::FGR32RegClass.contains(Reg)) { FPUBitmask |= (1 << RegNum); CSFPRegsSize += FGR32RegSize; } else if (Mips::AFGR64RegClass.contains(Reg)) { FPUBitmask |= (3 << RegNum); CSFPRegsSize += AFGR64RegSize; HasAFGR64Reg = true; } else if (Mips::GPR32RegClass.contains(Reg)) CPUBitmask |= (1 << RegNum); } // FP Regs are saved right below where the virtual frame pointer points to. FPUTopSavedRegOff = FPUBitmask ? (HasAFGR64Reg ? -AFGR64RegSize : -FGR32RegSize) : 0; // CPU Regs are saved below FP Regs. CPUTopSavedRegOff = CPUBitmask ? -CSFPRegsSize - CPURegSize : 0; MipsTargetStreamer &TS = getTargetStreamer(); // Print CPUBitmask TS.emitMask(CPUBitmask, CPUTopSavedRegOff); // Print FPUBitmask TS.emitFMask(FPUBitmask, FPUTopSavedRegOff); } //===----------------------------------------------------------------------===// // Frame and Set directives //===----------------------------------------------------------------------===// /// Frame Directive void MipsAsmPrinter::emitFrameDirective() { const TargetRegisterInfo &RI = *MF->getSubtarget().getRegisterInfo(); Register stackReg = RI.getFrameRegister(*MF); unsigned returnReg = RI.getRARegister(); unsigned stackSize = MF->getFrameInfo().getStackSize(); getTargetStreamer().emitFrame(stackReg, stackSize, returnReg); } /// Emit Set directives. const char *MipsAsmPrinter::getCurrentABIString() const { switch (static_cast(TM).getABI().GetEnumValue()) { case MipsABIInfo::ABI::O32: return "abi32"; case MipsABIInfo::ABI::N32: return "abiN32"; case MipsABIInfo::ABI::N64: return "abi64"; default: llvm_unreachable("Unknown Mips ABI"); } } void MipsAsmPrinter::emitFunctionEntryLabel() { MipsTargetStreamer &TS = getTargetStreamer(); // NaCl sandboxing requires that indirect call instructions are masked. // This means that function entry points should be bundle-aligned. if (Subtarget->isTargetNaCl()) emitAlignment(std::max(MF->getAlignment(), MIPS_NACL_BUNDLE_ALIGN)); if (Subtarget->inMicroMipsMode()) { TS.emitDirectiveSetMicroMips(); TS.setUsesMicroMips(); TS.updateABIInfo(*Subtarget); } else TS.emitDirectiveSetNoMicroMips(); if (Subtarget->inMips16Mode()) TS.emitDirectiveSetMips16(); else TS.emitDirectiveSetNoMips16(); TS.emitDirectiveEnt(*CurrentFnSym); OutStreamer->emitLabel(CurrentFnSym); } /// EmitFunctionBodyStart - Targets can override this to emit stuff before /// the first basic block in the function. void MipsAsmPrinter::emitFunctionBodyStart() { MipsTargetStreamer &TS = getTargetStreamer(); MCInstLowering.Initialize(&MF->getContext()); bool IsNakedFunction = MF->getFunction().hasFnAttribute(Attribute::Naked); if (!IsNakedFunction) emitFrameDirective(); if (!IsNakedFunction) printSavedRegsBitmask(); if (!Subtarget->inMips16Mode()) { TS.emitDirectiveSetNoReorder(); TS.emitDirectiveSetNoMacro(); TS.emitDirectiveSetNoAt(); } } /// EmitFunctionBodyEnd - Targets can override this to emit stuff after /// the last basic block in the function. void MipsAsmPrinter::emitFunctionBodyEnd() { MipsTargetStreamer &TS = getTargetStreamer(); // There are instruction for this macros, but they must // always be at the function end, and we can't emit and // break with BB logic. if (!Subtarget->inMips16Mode()) { TS.emitDirectiveSetAt(); TS.emitDirectiveSetMacro(); TS.emitDirectiveSetReorder(); } TS.emitDirectiveEnd(CurrentFnSym->getName()); // Make sure to terminate any constant pools that were at the end // of the function. if (!InConstantPool) return; InConstantPool = false; OutStreamer->emitDataRegion(MCDR_DataRegionEnd); } void MipsAsmPrinter::emitBasicBlockEnd(const MachineBasicBlock &MBB) { AsmPrinter::emitBasicBlockEnd(MBB); MipsTargetStreamer &TS = getTargetStreamer(); if (MBB.empty()) TS.emitDirectiveInsn(); } /// isBlockOnlyReachableByFallthough - Return true if the basic block has /// exactly one predecessor and the control transfer mechanism between /// the predecessor and this block is a fall-through. bool MipsAsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock* MBB) const { // The predecessor has to be immediately before this block. const MachineBasicBlock *Pred = *MBB->pred_begin(); // If the predecessor is a switch statement, assume a jump table // implementation, so it is not a fall through. if (const BasicBlock *bb = Pred->getBasicBlock()) if (isa(bb->getTerminator())) return false; // If this is a landing pad, it isn't a fall through. If it has no preds, // then nothing falls through to it. if (MBB->isEHPad() || MBB->pred_empty()) return false; // If there isn't exactly one predecessor, it can't be a fall through. MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; ++PI2; if (PI2 != MBB->pred_end()) return false; // The predecessor has to be immediately before this block. if (!Pred->isLayoutSuccessor(MBB)) return false; // If the block is completely empty, then it definitely does fall through. if (Pred->empty()) return true; // Otherwise, check the last instruction. // Check if the last terminator is an unconditional branch. MachineBasicBlock::const_iterator I = Pred->end(); while (I != Pred->begin() && !(--I)->isTerminator()) ; return !I->isBarrier(); } // Print out an operand for an inline asm expression. bool MipsAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum, const char *ExtraCode, raw_ostream &O) { // Does this asm operand have a single letter operand modifier? if (ExtraCode && ExtraCode[0]) { if (ExtraCode[1] != 0) return true; // Unknown modifier. const MachineOperand &MO = MI->getOperand(OpNum); switch (ExtraCode[0]) { default: // See if this is a generic print operand return AsmPrinter::PrintAsmOperand(MI, OpNum, ExtraCode, O); case 'X': // hex const int if (!MO.isImm()) return true; O << "0x" << Twine::utohexstr(MO.getImm()); return false; case 'x': // hex const int (low 16 bits) if (!MO.isImm()) return true; O << "0x" << Twine::utohexstr(MO.getImm() & 0xffff); return false; case 'd': // decimal const int if (!MO.isImm()) return true; O << MO.getImm(); return false; case 'm': // decimal const int minus 1 if (!MO.isImm()) return true; O << MO.getImm() - 1; return false; case 'y': // exact log2 if (!MO.isImm()) return true; if (!isPowerOf2_64(MO.getImm())) return true; O << Log2_64(MO.getImm()); return false; case 'z': // $0 if zero, regular printing otherwise if (MO.isImm() && MO.getImm() == 0) { O << "$0"; return false; } // If not, call printOperand as normal. break; case 'D': // Second part of a double word register operand case 'L': // Low order register of a double word register operand case 'M': // High order register of a double word register operand { if (OpNum == 0) return true; const MachineOperand &FlagsOP = MI->getOperand(OpNum - 1); if (!FlagsOP.isImm()) return true; unsigned Flags = FlagsOP.getImm(); unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags); // Number of registers represented by this operand. We are looking // for 2 for 32 bit mode and 1 for 64 bit mode. if (NumVals != 2) { if (Subtarget->isGP64bit() && NumVals == 1 && MO.isReg()) { Register Reg = MO.getReg(); O << '$' << MipsInstPrinter::getRegisterName(Reg); return false; } return true; } unsigned RegOp = OpNum; if (!Subtarget->isGP64bit()){ // Endianness reverses which register holds the high or low value // between M and L. switch(ExtraCode[0]) { case 'M': RegOp = (Subtarget->isLittle()) ? OpNum + 1 : OpNum; break; case 'L': RegOp = (Subtarget->isLittle()) ? OpNum : OpNum + 1; break; case 'D': // Always the second part RegOp = OpNum + 1; } if (RegOp >= MI->getNumOperands()) return true; const MachineOperand &MO = MI->getOperand(RegOp); if (!MO.isReg()) return true; Register Reg = MO.getReg(); O << '$' << MipsInstPrinter::getRegisterName(Reg); return false; } break; } case 'w': // Print MSA registers for the 'f' constraint // In LLVM, the 'w' modifier doesn't need to do anything. // We can just call printOperand as normal. break; } } printOperand(MI, OpNum, O); return false; } bool MipsAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum, const char *ExtraCode, raw_ostream &O) { assert(OpNum + 1 < MI->getNumOperands() && "Insufficient operands"); const MachineOperand &BaseMO = MI->getOperand(OpNum); const MachineOperand &OffsetMO = MI->getOperand(OpNum + 1); assert(BaseMO.isReg() && "Unexpected base pointer for inline asm memory operand."); assert(OffsetMO.isImm() && "Unexpected offset for inline asm memory operand."); int Offset = OffsetMO.getImm(); // Currently we are expecting either no ExtraCode or 'D','M','L'. if (ExtraCode) { switch (ExtraCode[0]) { case 'D': Offset += 4; break; case 'M': if (Subtarget->isLittle()) Offset += 4; break; case 'L': if (!Subtarget->isLittle()) Offset += 4; break; default: return true; // Unknown modifier. } } O << Offset << "($" << MipsInstPrinter::getRegisterName(BaseMO.getReg()) << ")"; return false; } void MipsAsmPrinter::printOperand(const MachineInstr *MI, int opNum, raw_ostream &O) { const MachineOperand &MO = MI->getOperand(opNum); bool closeP = false; if (MO.getTargetFlags()) closeP = true; switch(MO.getTargetFlags()) { case MipsII::MO_GPREL: O << "%gp_rel("; break; case MipsII::MO_GOT_CALL: O << "%call16("; break; case MipsII::MO_GOT: O << "%got("; break; case MipsII::MO_ABS_HI: O << "%hi("; break; case MipsII::MO_ABS_LO: O << "%lo("; break; case MipsII::MO_HIGHER: O << "%higher("; break; case MipsII::MO_HIGHEST: O << "%highest(("; break; case MipsII::MO_TLSGD: O << "%tlsgd("; break; case MipsII::MO_GOTTPREL: O << "%gottprel("; break; case MipsII::MO_TPREL_HI: O << "%tprel_hi("; break; case MipsII::MO_TPREL_LO: O << "%tprel_lo("; break; case MipsII::MO_GPOFF_HI: O << "%hi(%neg(%gp_rel("; break; case MipsII::MO_GPOFF_LO: O << "%lo(%neg(%gp_rel("; break; case MipsII::MO_GOT_DISP: O << "%got_disp("; break; case MipsII::MO_GOT_PAGE: O << "%got_page("; break; case MipsII::MO_GOT_OFST: O << "%got_ofst("; break; } switch (MO.getType()) { case MachineOperand::MO_Register: O << '$' << StringRef(MipsInstPrinter::getRegisterName(MO.getReg())).lower(); break; case MachineOperand::MO_Immediate: O << MO.getImm(); break; case MachineOperand::MO_MachineBasicBlock: MO.getMBB()->getSymbol()->print(O, MAI); return; case MachineOperand::MO_GlobalAddress: PrintSymbolOperand(MO, O); break; case MachineOperand::MO_BlockAddress: { MCSymbol *BA = GetBlockAddressSymbol(MO.getBlockAddress()); O << BA->getName(); break; } case MachineOperand::MO_ConstantPoolIndex: O << getDataLayout().getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_" << MO.getIndex(); if (MO.getOffset()) O << "+" << MO.getOffset(); break; default: llvm_unreachable(""); } if (closeP) O << ")"; } void MipsAsmPrinter:: printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O) { // Load/Store memory operands -- imm($reg) // If PIC target the target is loaded as the // pattern lw $25,%call16($28) // opNum can be invalid if instruction has reglist as operand. // MemOperand is always last operand of instruction (base + offset). switch (MI->getOpcode()) { default: break; case Mips::SWM32_MM: case Mips::LWM32_MM: opNum = MI->getNumOperands() - 2; break; } printOperand(MI, opNum+1, O); O << "("; printOperand(MI, opNum, O); O << ")"; } void MipsAsmPrinter:: printMemOperandEA(const MachineInstr *MI, int opNum, raw_ostream &O) { // when using stack locations for not load/store instructions // print the same way as all normal 3 operand instructions. printOperand(MI, opNum, O); O << ", "; printOperand(MI, opNum+1, O); } void MipsAsmPrinter:: printFCCOperand(const MachineInstr *MI, int opNum, raw_ostream &O, const char *Modifier) { const MachineOperand &MO = MI->getOperand(opNum); O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm()); } void MipsAsmPrinter:: printRegisterList(const MachineInstr *MI, int opNum, raw_ostream &O) { for (int i = opNum, e = MI->getNumOperands(); i != e; ++i) { if (i != opNum) O << ", "; printOperand(MI, i, O); } } void MipsAsmPrinter::emitStartOfAsmFile(Module &M) { MipsTargetStreamer &TS = getTargetStreamer(); // MipsTargetStreamer has an initialization order problem when emitting an // object file directly (see MipsTargetELFStreamer for full details). Work // around it by re-initializing the PIC state here. TS.setPic(OutContext.getObjectFileInfo()->isPositionIndependent()); // Compute MIPS architecture attributes based on the default subtarget // that we'd have constructed. Module level directives aren't LTO // clean anyhow. // FIXME: For ifunc related functions we could iterate over and look // for a feature string that doesn't match the default one. const Triple &TT = TM.getTargetTriple(); StringRef CPU = MIPS_MC::selectMipsCPU(TT, TM.getTargetCPU()); StringRef FS = TM.getTargetFeatureString(); const MipsTargetMachine &MTM = static_cast(TM); const MipsSubtarget STI(TT, CPU, FS, MTM.isLittleEndian(), MTM, std::nullopt); bool IsABICalls = STI.isABICalls(); const MipsABIInfo &ABI = MTM.getABI(); if (IsABICalls) { TS.emitDirectiveAbiCalls(); // FIXME: This condition should be a lot more complicated that it is here. // Ideally it should test for properties of the ABI and not the ABI // itself. // For the moment, I'm only correcting enough to make MIPS-IV work. if (!isPositionIndependent() && STI.hasSym32()) TS.emitDirectiveOptionPic0(); } // Tell the assembler which ABI we are using std::string SectionName = std::string(".mdebug.") + getCurrentABIString(); OutStreamer->switchSection( OutContext.getELFSection(SectionName, ELF::SHT_PROGBITS, 0)); // NaN: At the moment we only support: // 1. .nan legacy (default) // 2. .nan 2008 STI.isNaN2008() ? TS.emitDirectiveNaN2008() : TS.emitDirectiveNaNLegacy(); // TODO: handle O64 ABI TS.updateABIInfo(STI); // We should always emit a '.module fp=...' but binutils 2.24 does not accept // it. We therefore emit it when it contradicts the ABI defaults (-mfpxx or // -mfp64) and omit it otherwise. if ((ABI.IsO32() && (STI.isABI_FPXX() || STI.isFP64bit())) || STI.useSoftFloat()) TS.emitDirectiveModuleFP(); // We should always emit a '.module [no]oddspreg' but binutils 2.24 does not // accept it. We therefore emit it when it contradicts the default or an // option has changed the default (i.e. FPXX) and omit it otherwise. if (ABI.IsO32() && (!STI.useOddSPReg() || STI.isABI_FPXX())) TS.emitDirectiveModuleOddSPReg(); // Switch to the .text section. OutStreamer->switchSection(getObjFileLowering().getTextSection()); } void MipsAsmPrinter::emitInlineAsmStart() const { MipsTargetStreamer &TS = getTargetStreamer(); // GCC's choice of assembler options for inline assembly code ('at', 'macro' // and 'reorder') is different from LLVM's choice for generated code ('noat', // 'nomacro' and 'noreorder'). // In order to maintain compatibility with inline assembly code which depends // on GCC's assembler options being used, we have to switch to those options // for the duration of the inline assembly block and then switch back. TS.emitDirectiveSetPush(); TS.emitDirectiveSetAt(); TS.emitDirectiveSetMacro(); TS.emitDirectiveSetReorder(); OutStreamer->addBlankLine(); } void MipsAsmPrinter::emitInlineAsmEnd(const MCSubtargetInfo &StartInfo, const MCSubtargetInfo *EndInfo) const { OutStreamer->addBlankLine(); getTargetStreamer().emitDirectiveSetPop(); } void MipsAsmPrinter::EmitJal(const MCSubtargetInfo &STI, MCSymbol *Symbol) { MCInst I; I.setOpcode(Mips::JAL); I.addOperand( MCOperand::createExpr(MCSymbolRefExpr::create(Symbol, OutContext))); OutStreamer->emitInstruction(I, STI); } void MipsAsmPrinter::EmitInstrReg(const MCSubtargetInfo &STI, unsigned Opcode, unsigned Reg) { MCInst I; I.setOpcode(Opcode); I.addOperand(MCOperand::createReg(Reg)); OutStreamer->emitInstruction(I, STI); } void MipsAsmPrinter::EmitInstrRegReg(const MCSubtargetInfo &STI, unsigned Opcode, unsigned Reg1, unsigned Reg2) { MCInst I; // // Because of the current td files for Mips32, the operands for MTC1 // appear backwards from their normal assembly order. It's not a trivial // change to fix this in the td file so we adjust for it here. // if (Opcode == Mips::MTC1) { unsigned Temp = Reg1; Reg1 = Reg2; Reg2 = Temp; } I.setOpcode(Opcode); I.addOperand(MCOperand::createReg(Reg1)); I.addOperand(MCOperand::createReg(Reg2)); OutStreamer->emitInstruction(I, STI); } void MipsAsmPrinter::EmitInstrRegRegReg(const MCSubtargetInfo &STI, unsigned Opcode, unsigned Reg1, unsigned Reg2, unsigned Reg3) { MCInst I; I.setOpcode(Opcode); I.addOperand(MCOperand::createReg(Reg1)); I.addOperand(MCOperand::createReg(Reg2)); I.addOperand(MCOperand::createReg(Reg3)); OutStreamer->emitInstruction(I, STI); } void MipsAsmPrinter::EmitMovFPIntPair(const MCSubtargetInfo &STI, unsigned MovOpc, unsigned Reg1, unsigned Reg2, unsigned FPReg1, unsigned FPReg2, bool LE) { if (!LE) { unsigned temp = Reg1; Reg1 = Reg2; Reg2 = temp; } EmitInstrRegReg(STI, MovOpc, Reg1, FPReg1); EmitInstrRegReg(STI, MovOpc, Reg2, FPReg2); } void MipsAsmPrinter::EmitSwapFPIntParams(const MCSubtargetInfo &STI, Mips16HardFloatInfo::FPParamVariant PV, bool LE, bool ToFP) { using namespace Mips16HardFloatInfo; unsigned MovOpc = ToFP ? Mips::MTC1 : Mips::MFC1; switch (PV) { case FSig: EmitInstrRegReg(STI, MovOpc, Mips::A0, Mips::F12); break; case FFSig: EmitMovFPIntPair(STI, MovOpc, Mips::A0, Mips::A1, Mips::F12, Mips::F14, LE); break; case FDSig: EmitInstrRegReg(STI, MovOpc, Mips::A0, Mips::F12); EmitMovFPIntPair(STI, MovOpc, Mips::A2, Mips::A3, Mips::F14, Mips::F15, LE); break; case DSig: EmitMovFPIntPair(STI, MovOpc, Mips::A0, Mips::A1, Mips::F12, Mips::F13, LE); break; case DDSig: EmitMovFPIntPair(STI, MovOpc, Mips::A0, Mips::A1, Mips::F12, Mips::F13, LE); EmitMovFPIntPair(STI, MovOpc, Mips::A2, Mips::A3, Mips::F14, Mips::F15, LE); break; case DFSig: EmitMovFPIntPair(STI, MovOpc, Mips::A0, Mips::A1, Mips::F12, Mips::F13, LE); EmitInstrRegReg(STI, MovOpc, Mips::A2, Mips::F14); break; case NoSig: return; } } void MipsAsmPrinter::EmitSwapFPIntRetval( const MCSubtargetInfo &STI, Mips16HardFloatInfo::FPReturnVariant RV, bool LE) { using namespace Mips16HardFloatInfo; unsigned MovOpc = Mips::MFC1; switch (RV) { case FRet: EmitInstrRegReg(STI, MovOpc, Mips::V0, Mips::F0); break; case DRet: EmitMovFPIntPair(STI, MovOpc, Mips::V0, Mips::V1, Mips::F0, Mips::F1, LE); break; case CFRet: EmitMovFPIntPair(STI, MovOpc, Mips::V0, Mips::V1, Mips::F0, Mips::F1, LE); break; case CDRet: EmitMovFPIntPair(STI, MovOpc, Mips::V0, Mips::V1, Mips::F0, Mips::F1, LE); EmitMovFPIntPair(STI, MovOpc, Mips::A0, Mips::A1, Mips::F2, Mips::F3, LE); break; case NoFPRet: break; } } void MipsAsmPrinter::EmitFPCallStub( const char *Symbol, const Mips16HardFloatInfo::FuncSignature *Signature) { using namespace Mips16HardFloatInfo; MCSymbol *MSymbol = OutContext.getOrCreateSymbol(StringRef(Symbol)); bool LE = getDataLayout().isLittleEndian(); // Construct a local MCSubtargetInfo here. // This is because the MachineFunction won't exist (but have not yet been // freed) and since we're at the global level we can use the default // constructed subtarget. std::unique_ptr STI(TM.getTarget().createMCSubtargetInfo( TM.getTargetTriple().str(), TM.getTargetCPU(), TM.getTargetFeatureString())); // // .global xxxx // OutStreamer->emitSymbolAttribute(MSymbol, MCSA_Global); const char *RetType; // // make the comment field identifying the return and parameter // types of the floating point stub // # Stub function to call rettype xxxx (params) // switch (Signature->RetSig) { case FRet: RetType = "float"; break; case DRet: RetType = "double"; break; case CFRet: RetType = "complex"; break; case CDRet: RetType = "double complex"; break; case NoFPRet: RetType = ""; break; } const char *Parms; switch (Signature->ParamSig) { case FSig: Parms = "float"; break; case FFSig: Parms = "float, float"; break; case FDSig: Parms = "float, double"; break; case DSig: Parms = "double"; break; case DDSig: Parms = "double, double"; break; case DFSig: Parms = "double, float"; break; case NoSig: Parms = ""; break; } OutStreamer->AddComment("\t# Stub function to call " + Twine(RetType) + " " + Twine(Symbol) + " (" + Twine(Parms) + ")"); // // probably not necessary but we save and restore the current section state // OutStreamer->pushSection(); // // .section mips16.call.fpxxxx,"ax",@progbits // MCSectionELF *M = OutContext.getELFSection( ".mips16.call.fp." + std::string(Symbol), ELF::SHT_PROGBITS, ELF::SHF_ALLOC | ELF::SHF_EXECINSTR); OutStreamer->switchSection(M, nullptr); // // .align 2 // OutStreamer->emitValueToAlignment(Align(4)); MipsTargetStreamer &TS = getTargetStreamer(); // // .set nomips16 // .set nomicromips // TS.emitDirectiveSetNoMips16(); TS.emitDirectiveSetNoMicroMips(); // // .ent __call_stub_fp_xxxx // .type __call_stub_fp_xxxx,@function // __call_stub_fp_xxxx: // std::string x = "__call_stub_fp_" + std::string(Symbol); MCSymbolELF *Stub = cast(OutContext.getOrCreateSymbol(StringRef(x))); TS.emitDirectiveEnt(*Stub); MCSymbol *MType = OutContext.getOrCreateSymbol("__call_stub_fp_" + Twine(Symbol)); OutStreamer->emitSymbolAttribute(MType, MCSA_ELF_TypeFunction); OutStreamer->emitLabel(Stub); // Only handle non-pic for now. assert(!isPositionIndependent() && "should not be here if we are compiling pic"); TS.emitDirectiveSetReorder(); // // We need to add a MipsMCExpr class to MCTargetDesc to fully implement // stubs without raw text but this current patch is for compiler generated // functions and they all return some value. // The calling sequence for non pic is different in that case and we need // to implement %lo and %hi in order to handle the case of no return value // See the corresponding method in Mips16HardFloat for details. // // mov the return address to S2. // we have no stack space to store it and we are about to make another call. // We need to make sure that the enclosing function knows to save S2 // This should have already been handled. // // Mov $18, $31 EmitInstrRegRegReg(*STI, Mips::OR, Mips::S2, Mips::RA, Mips::ZERO); EmitSwapFPIntParams(*STI, Signature->ParamSig, LE, true); // Jal xxxx // EmitJal(*STI, MSymbol); // fix return values EmitSwapFPIntRetval(*STI, Signature->RetSig, LE); // // do the return // if (Signature->RetSig == NoFPRet) // llvm_unreachable("should not be any stubs here with no return value"); // else EmitInstrReg(*STI, Mips::JR, Mips::S2); MCSymbol *Tmp = OutContext.createTempSymbol(); OutStreamer->emitLabel(Tmp); const MCSymbolRefExpr *E = MCSymbolRefExpr::create(Stub, OutContext); const MCSymbolRefExpr *T = MCSymbolRefExpr::create(Tmp, OutContext); const MCExpr *T_min_E = MCBinaryExpr::createSub(T, E, OutContext); OutStreamer->emitELFSize(Stub, T_min_E); TS.emitDirectiveEnd(x); OutStreamer->popSection(); } void MipsAsmPrinter::emitEndOfAsmFile(Module &M) { // Emit needed stubs // for (std::map< const char *, const Mips16HardFloatInfo::FuncSignature *>::const_iterator it = StubsNeeded.begin(); it != StubsNeeded.end(); ++it) { const char *Symbol = it->first; const Mips16HardFloatInfo::FuncSignature *Signature = it->second; EmitFPCallStub(Symbol, Signature); } // return to the text section OutStreamer->switchSection(OutContext.getObjectFileInfo()->getTextSection()); } void MipsAsmPrinter::EmitSled(const MachineInstr &MI, SledKind Kind) { const uint8_t NoopsInSledCount = Subtarget->isGP64bit() ? 15 : 11; // For mips32 we want to emit the following pattern: // // .Lxray_sled_N: // ALIGN // B .tmpN // 11 NOP instructions (44 bytes) // ADDIU T9, T9, 52 // .tmpN // // We need the 44 bytes (11 instructions) because at runtime, we'd // be patching over the full 48 bytes (12 instructions) with the following // pattern: // // ADDIU SP, SP, -8 // NOP // SW RA, 4(SP) // SW T9, 0(SP) // LUI T9, %hi(__xray_FunctionEntry/Exit) // ORI T9, T9, %lo(__xray_FunctionEntry/Exit) // LUI T0, %hi(function_id) // JALR T9 // ORI T0, T0, %lo(function_id) // LW T9, 0(SP) // LW RA, 4(SP) // ADDIU SP, SP, 8 // // We add 52 bytes to t9 because we want to adjust the function pointer to // the actual start of function i.e. the address just after the noop sled. // We do this because gp displacement relocation is emitted at the start of // of the function i.e after the nop sled and to correctly calculate the // global offset table address, t9 must hold the address of the instruction // containing the gp displacement relocation. // FIXME: Is this correct for the static relocation model? // // For mips64 we want to emit the following pattern: // // .Lxray_sled_N: // ALIGN // B .tmpN // 15 NOP instructions (60 bytes) // .tmpN // // We need the 60 bytes (15 instructions) because at runtime, we'd // be patching over the full 64 bytes (16 instructions) with the following // pattern: // // DADDIU SP, SP, -16 // NOP // SD RA, 8(SP) // SD T9, 0(SP) // LUI T9, %highest(__xray_FunctionEntry/Exit) // ORI T9, T9, %higher(__xray_FunctionEntry/Exit) // DSLL T9, T9, 16 // ORI T9, T9, %hi(__xray_FunctionEntry/Exit) // DSLL T9, T9, 16 // ORI T9, T9, %lo(__xray_FunctionEntry/Exit) // LUI T0, %hi(function_id) // JALR T9 // ADDIU T0, T0, %lo(function_id) // LD T9, 0(SP) // LD RA, 8(SP) // DADDIU SP, SP, 16 // OutStreamer->emitCodeAlignment(Align(4), &getSubtargetInfo()); auto CurSled = OutContext.createTempSymbol("xray_sled_", true); OutStreamer->emitLabel(CurSled); auto Target = OutContext.createTempSymbol(); // Emit "B .tmpN" instruction, which jumps over the nop sled to the actual // start of function const MCExpr *TargetExpr = MCSymbolRefExpr::create( Target, MCSymbolRefExpr::VariantKind::VK_None, OutContext); EmitToStreamer(*OutStreamer, MCInstBuilder(Mips::BEQ) .addReg(Mips::ZERO) .addReg(Mips::ZERO) .addExpr(TargetExpr)); for (int8_t I = 0; I < NoopsInSledCount; I++) EmitToStreamer(*OutStreamer, MCInstBuilder(Mips::SLL) .addReg(Mips::ZERO) .addReg(Mips::ZERO) .addImm(0)); OutStreamer->emitLabel(Target); if (!Subtarget->isGP64bit()) { EmitToStreamer(*OutStreamer, MCInstBuilder(Mips::ADDiu) .addReg(Mips::T9) .addReg(Mips::T9) .addImm(0x34)); } recordSled(CurSled, MI, Kind, 2); } void MipsAsmPrinter::LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI) { EmitSled(MI, SledKind::FUNCTION_ENTER); } void MipsAsmPrinter::LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI) { EmitSled(MI, SledKind::FUNCTION_EXIT); } void MipsAsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI) { EmitSled(MI, SledKind::TAIL_CALL); } void MipsAsmPrinter::PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS) { // TODO: implement } // Emit .dtprelword or .dtpreldword directive // and value for debug thread local expression. void MipsAsmPrinter::emitDebugValue(const MCExpr *Value, unsigned Size) const { if (auto *MipsExpr = dyn_cast(Value)) { if (MipsExpr && MipsExpr->getKind() == MipsMCExpr::MEK_DTPREL) { switch (Size) { case 4: OutStreamer->emitDTPRel32Value(MipsExpr->getSubExpr()); break; case 8: OutStreamer->emitDTPRel64Value(MipsExpr->getSubExpr()); break; default: llvm_unreachable("Unexpected size of expression value."); } return; } } AsmPrinter::emitDebugValue(Value, Size); } // Align all targets of indirect branches on bundle size. Used only if target // is NaCl. void MipsAsmPrinter::NaClAlignIndirectJumpTargets(MachineFunction &MF) { // Align all blocks that are jumped to through jump table. if (MachineJumpTableInfo *JtInfo = MF.getJumpTableInfo()) { const std::vector &JT = JtInfo->getJumpTables(); for (const auto &I : JT) { const std::vector &MBBs = I.MBBs; for (MachineBasicBlock *MBB : MBBs) MBB->setAlignment(MIPS_NACL_BUNDLE_ALIGN); } } // If basic block address is taken, block can be target of indirect branch. for (auto &MBB : MF) { if (MBB.hasAddressTaken()) MBB.setAlignment(MIPS_NACL_BUNDLE_ALIGN); } } bool MipsAsmPrinter::isLongBranchPseudo(int Opcode) const { return (Opcode == Mips::LONG_BRANCH_LUi || Opcode == Mips::LONG_BRANCH_LUi2Op || Opcode == Mips::LONG_BRANCH_LUi2Op_64 || Opcode == Mips::LONG_BRANCH_ADDiu || Opcode == Mips::LONG_BRANCH_ADDiu2Op || Opcode == Mips::LONG_BRANCH_DADDiu || Opcode == Mips::LONG_BRANCH_DADDiu2Op); } // Force static initialization. extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeMipsAsmPrinter() { RegisterAsmPrinter X(getTheMipsTarget()); RegisterAsmPrinter Y(getTheMipselTarget()); RegisterAsmPrinter A(getTheMips64Target()); RegisterAsmPrinter B(getTheMips64elTarget()); }