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llvm-6502/lib/Target/Mips/MipsAsmPrinter.cpp
Toma Tabacu 52c5645668 [mips] Refactor saved-registers bitmask creation in MipsAsmPrinter::printSavedRegsBitmask. NFC. 
Summary:
Make the code more readable by fusing the for-loops together and explicitly checking for each register class.

Also, this version is more straightforward because it doesn't assume that FPU registers always come before CPU registers in the CalleeSavedInfo vector.

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D8033

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234475 91177308-0d34-0410-b5e6-96231b3b80d8
2015-04-09 10:54:16 +00:00

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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 "InstPrinter/MipsInstPrinter.h"
#include "MCTargetDesc/MipsBaseInfo.h"
#include "MCTargetDesc/MipsMCNaCl.h"
#include "Mips.h"
#include "MipsAsmPrinter.h"
#include "MipsInstrInfo.h"
#include "MipsMCInstLower.h"
#include "MipsTargetMachine.h"
#include "MipsTargetStreamer.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Mangler.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCELFStreamer.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
#include "llvm/Target/TargetOptions.h"
#include <string>
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>();
// Initialize TargetLoweringObjectFile.
const_cast<TargetLoweringObjectFile &>(getObjFileLowering())
.Initialize(OutContext, TM);
MipsFI = MF.getInfo<MipsFunctionInfo>();
if (Subtarget->inMips16Mode())
for (std::map<
const char *,
const llvm::Mips16HardFloatInfo::FuncSignature *>::const_iterator
it = MipsFI->StubsNeeded.begin();
it != MipsFI->StubsNeeded.end(); ++it) {
const char *Symbol = it->first;
const llvm::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);
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;
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)
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();
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 && MI->getOpcode() != Mips::CONSTPOOL_ENTRY) {
OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
InConstantPool = false;
}
if (MI->getOpcode() == 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(MCPE.Val.ConstVal);
return;
}
MachineBasicBlock::const_instr_iterator I = MI;
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) {
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 = Mips::GPR32RegClass.getSize();
unsigned FGR32RegSize = Mips::FGR32RegClass.getSize();
unsigned AFGR64RegSize = Mips::AFGR64RegClass.getSize();
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";
case MipsABIInfo::ABI::EABI: return "eabi32"; // TODO: handle eabi64
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();
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);
}
/// 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->isLandingPad() || 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" << StringRef(utohexstr(MO.getImm())).lower();
return false;
case 'x': // hex const int (low 16 bits)
if ((MO.getType()) != MachineOperand::MO_Immediate)
return true;
O << "0x" << StringRef(utohexstr(MO.getImm() & 0xffff)).lower();
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()){
// Endianess 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 DataLayout *DL = TM.getDataLayout();
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_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 << '$'
<< StringRef(MipsInstPrinter::getRegisterName(MO.getReg())).lower();
break;
case MachineOperand::MO_Immediate:
O << MO.getImm();
break;
case MachineOperand::MO_MachineBasicBlock:
O << *MO.getMBB()->getSymbol();
return;
case MachineOperand::MO_GlobalAddress:
O << *getSymbol(MO.getGlobal());
break;
case MachineOperand::MO_BlockAddress: {
MCSymbol *BA = GetBlockAddressSymbol(MO.getBlockAddress());
O << BA->getName();
break;
}
case MachineOperand::MO_ConstantPoolIndex:
O << DL->getPrivateGlobalPrefix() << "CPI"
<< getFunctionNumber() << "_" << MO.getIndex();
if (MO.getOffset())
O << "+" << MO.getOffset();
break;
default:
llvm_unreachable("<unknown operand type>");
}
if (closeP) O << ")";
}
void MipsAsmPrinter::printUnsignedImm(const MachineInstr *MI, int opNum,
raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(opNum);
if (MO.isImm())
O << (unsigned short int)MO.getImm();
else
printOperand(MI, opNum, O);
}
void MipsAsmPrinter::printUnsignedImm8(const MachineInstr *MI, int opNum,
raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(opNum);
if (MO.isImm())
O << (unsigned short int)(unsigned char)MO.getImm();
else
printOperand(MI, opNum, O);
}
void MipsAsmPrinter::
printMemOperand(const MachineInstr *MI, int opNum, raw_ostream &O) {
// Load/Store memory operands -- imm($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);
return;
}
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) {
// 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.
StringRef TT = TM.getTargetTriple();
StringRef CPU =
MIPS_MC::selectMipsCPU(TM.getTargetTriple(), TM.getTargetCPU());
StringRef FS = TM.getTargetFeatureString();
const MipsTargetMachine &MTM = static_cast<const MipsTargetMachine &>(TM);
const MipsSubtarget STI(TT, CPU, FS, MTM.isLittleEndian(), MTM);
bool IsABICalls = STI.isABICalls();
const MipsABIInfo &ABI = MTM.getABI();
if (IsABICalls) {
getTargetStreamer().emitDirectiveAbiCalls();
Reloc::Model RM = TM.getRelocationModel();
// 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 (RM == Reloc::Static && !ABI.IsN64())
getTargetStreamer().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() ? getTargetStreamer().emitDirectiveNaN2008()
: getTargetStreamer().emitDirectiveNaNLegacy();
// TODO: handle O64 ABI
if (ABI.IsEABI()) {
if (STI.isGP32bit())
OutStreamer.SwitchSection(OutContext.getELFSection(".gcc_compiled_long32",
ELF::SHT_PROGBITS, 0));
else
OutStreamer.SwitchSection(OutContext.getELFSection(".gcc_compiled_long64",
ELF::SHT_PROGBITS, 0));
}
getTargetStreamer().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()))
getTargetStreamer().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()))
getTargetStreamer().emitDirectiveModuleOddSPReg(STI.useOddSPReg(),
ABI.IsO32());
}
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) {
MCSymbol *MSymbol = OutContext.GetOrCreateSymbol(StringRef(Symbol));
using namespace Mips16HardFloatInfo;
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(), 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
//
const 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);
MCSymbol *Stub = 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(TM.getRelocationModel() != Reloc::PIC_ &&
"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::ADDu, 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 llvm::Mips16HardFloatInfo::FuncSignature *>::const_iterator
it = StubsNeeded.begin();
it != StubsNeeded.end(); ++it) {
const char *Symbol = it->first;
const llvm::Mips16HardFloatInfo::FuncSignature *Signature = it->second;
EmitFPCallStub(Symbol, Signature);
}
// return to the text section
OutStreamer.SwitchSection(OutContext.getObjectFileInfo()->getTextSection());
}
void MipsAsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
raw_ostream &OS) {
// TODO: implement
}
// 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 (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
MBB != E; ++MBB) {
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(TheMipsTarget);
RegisterAsmPrinter<MipsAsmPrinter> Y(TheMipselTarget);
RegisterAsmPrinter<MipsAsmPrinter> A(TheMips64Target);
RegisterAsmPrinter<MipsAsmPrinter> B(TheMips64elTarget);
}
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