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llvm-project/llvm/lib/Target/Mips/MipsAsmPrinter.cpp

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//===- MipsAsmPrinter.cpp - Mips LLVM Assembly Printer --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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 "InstPrinter/MipsInstPrinter.h"
#include "MCTargetDesc/MipsABIInfo.h"
#include "MCTargetDesc/MipsBaseInfo.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 "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/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/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetSubtargetInfo.h"
#include <cassert>
#include <cstdint>
#include <map>
#include <memory>
#include <string>
#include <vector>
using namespace llvm;
#define DEBUG_TYPE "mips-asm-printer"
MipsTargetStreamer &MipsAsmPrinter::getTargetStreamer() const {
return static_cast<MipsTargetStreamer &>(*OutStreamer->getTargetStreamer());
}
bool MipsAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
Subtarget = &MF.getSubtarget<MipsSubtarget>();
MipsFI = MF.getInfo<MipsFunctionInfo>();
if (Subtarget->inMips16Mode())
for (std::map<
const char *,
const Mips16HardFloatInfo::FuncSignature *>::const_iterator
it = MipsFI->StubsNeeded.begin();
it != MipsFI->StubsNeeded.end(); ++it) {
const char *Symbol = it->first;
const Mips16HardFloatInfo::FuncSignature *Signature = it->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);
}
void MipsAsmPrinter::EmitInstruction(const MachineInstr *MI) {
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 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;
}
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;
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<CalleeSavedInfo> &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) {
unsigned 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();
unsigned 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<MipsTargetMachine &>(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();
} 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<SwitchInst>(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,
unsigned AsmVariant, 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,AsmVariant,ExtraCode,O);
case 'X': // hex const int
if ((MO.getType()) != MachineOperand::MO_Immediate)
return true;
O << "0x" << Twine::utohexstr(MO.getImm());
return false;
case 'x': // hex const int (low 16 bits)
if ((MO.getType()) != MachineOperand::MO_Immediate)
return true;
O << "0x" << Twine::utohexstr(MO.getImm() & 0xffff);
return false;
case 'd': // decimal const int
if ((MO.getType()) != MachineOperand::MO_Immediate)
return true;
O << MO.getImm();
return false;
case 'm': // decimal const int minus 1
if ((MO.getType()) != MachineOperand::MO_Immediate)
return true;
O << MO.getImm() - 1;
return false;
case 'z':
// $0 if zero, regular printing otherwise
if (MO.getType() == MachineOperand::MO_Immediate && MO.getImm() == 0) {
O << "$0";
return false;
}
// If not, call printOperand as normal.
break;
case 'D': // Second part of a double word register operand
case 'L': // Low order register of a double word register operand
case 'M': // High order register of a double word register operand
{
if (OpNum == 0)
return true;
const MachineOperand &FlagsOP = MI->getOperand(OpNum - 1);
if (!FlagsOP.isImm())
return true;
unsigned Flags = FlagsOP.getImm();
unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
// Number of registers represented by this operand. We are looking
// for 2 for 32 bit mode and 1 for 64 bit mode.
if (NumVals != 2) {
if (Subtarget->isGP64bit() && NumVals == 1 && MO.isReg()) {
unsigned Reg = MO.getReg();
O << '$' << 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;
unsigned Reg = MO.getReg();
O << '$' << MipsInstPrinter::getRegisterName(Reg);
return false;
}
}
case 'w':
// Print MSA registers for the 'f' constraint
// In LLVM, the 'w' modifier doesn't need to do anything.
// We can just call printOperand as normal.
break;
}
}
printOperand(MI, OpNum, O);
return false;
}
bool MipsAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
unsigned OpNum, unsigned AsmVariant,
const char *ExtraCode,
raw_ostream &O) {
assert(OpNum + 1 < MI->getNumOperands() && "Insufficient operands");
const MachineOperand &BaseMO = MI->getOperand(OpNum);
const MachineOperand &OffsetMO = MI->getOperand(OpNum + 1);
assert(BaseMO.isReg() && "Unexpected base pointer for inline asm memory operand.");
assert(OffsetMO.isImm() && "Unexpected offset for inline asm memory operand.");
int Offset = OffsetMO.getImm();
// Currently we are expecting either no ExtraCode or 'D'
if (ExtraCode) {
if (ExtraCode[0] == 'D')
Offset += 4;
else
return true; // Unknown modifier.
// FIXME: M = high order bits
// FIXME: L = low order bits
}
O << Offset << "($" << 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 << '$'
<< StringRef(MipsInstPrinter::getRegisterName(MO.getReg())).lower();
break;
case MachineOperand::MO_Immediate:
O << MO.getImm();
break;
case MachineOperand::MO_MachineBasicBlock:
MO.getMBB()->getSymbol()->print(O, MAI);
return;
case MachineOperand::MO_GlobalAddress:
getSymbol(MO.getGlobal())->print(O, MAI);
break;
case MachineOperand::MO_BlockAddress: {
MCSymbol *BA = GetBlockAddressSymbol(MO.getBlockAddress());
O << BA->getName();
break;
}
case MachineOperand::MO_ConstantPoolIndex:
O << getDataLayout().getPrivateGlobalPrefix() << "CPI"
<< getFunctionNumber() << "_" << MO.getIndex();
if (MO.getOffset())
O << "+" << MO.getOffset();
break;
default:
llvm_unreachable("<unknown operand type>");
}
if (closeP) O << ")";
}
void MipsAsmPrinter::
printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O) {
// Load/Store memory operands -- imm($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<const MipsTargetMachine &>(TM);
const MipsSubtarget STI(TT, CPU, FS, MTM.isLittleEndian(), MTM, 0);
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()))
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();
}
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<MCSubtargetInfo> 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(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<MCSymbolELF>(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(4);
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);
}
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::EmitDebugThreadLocal(const MCExpr *Value,
unsigned Size) const {
switch (Size) {
case 4:
OutStreamer->EmitDTPRel32Value(Value);
break;
case 8:
OutStreamer->EmitDTPRel64Value(Value);
break;
default:
llvm_unreachable("Unexpected size of expression value.");
}
}
// 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<MachineJumpTableEntry> &JT = JtInfo->getJumpTables();
for (unsigned I = 0; I < JT.size(); ++I) {
const std::vector<MachineBasicBlock*> &MBBs = JT[I].MBBs;
for (unsigned J = 0; J < MBBs.size(); ++J)
MBBs[J]->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_ADDiu
|| Opcode == Mips::LONG_BRANCH_DADDiu);
}
// Force static initialization.
extern "C" void LLVMInitializeMipsAsmPrinter() {
RegisterAsmPrinter<MipsAsmPrinter> X(getTheMipsTarget());
RegisterAsmPrinter<MipsAsmPrinter> Y(getTheMipselTarget());
RegisterAsmPrinter<MipsAsmPrinter> A(getTheMips64Target());
RegisterAsmPrinter<MipsAsmPrinter> B(getTheMips64elTarget());
}
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