1 //===-- MipsAsmPrinter.cpp - Mips LLVM assembly writer --------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains a printer that converts from our internal representation
11 // of machine-dependent LLVM code to GAS-format MIPS assembly language.
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "mips-asm-printer"
18 #include "MipsSubtarget.h"
19 #include "MipsInstrInfo.h"
20 #include "MipsTargetMachine.h"
21 #include "MipsMachineFunction.h"
22 #include "llvm/Constants.h"
23 #include "llvm/DerivedTypes.h"
24 #include "llvm/Module.h"
25 #include "llvm/CodeGen/AsmPrinter.h"
26 #include "llvm/CodeGen/MachineFunctionPass.h"
27 #include "llvm/CodeGen/MachineConstantPool.h"
28 #include "llvm/CodeGen/MachineFrameInfo.h"
29 #include "llvm/CodeGen/MachineInstr.h"
30 #include "llvm/Target/TargetAsmInfo.h"
31 #include "llvm/Target/TargetData.h"
32 #include "llvm/Target/TargetMachine.h"
33 #include "llvm/Target/TargetOptions.h"
34 #include "llvm/Support/Mangler.h"
35 #include "llvm/ADT/Statistic.h"
36 #include "llvm/ADT/StringExtras.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/CommandLine.h"
39 #include "llvm/Support/MathExtras.h"
40 #include "llvm/Support/raw_ostream.h"
45 STATISTIC(EmittedInsts, "Number of machine instrs printed");
48 struct VISIBILITY_HIDDEN MipsAsmPrinter : public AsmPrinter {
50 const MipsSubtarget *Subtarget;
52 MipsAsmPrinter(raw_ostream &O, MipsTargetMachine &TM,
53 const TargetAsmInfo *T):
54 AsmPrinter(O, TM, T) {
55 Subtarget = &TM.getSubtarget<MipsSubtarget>();
58 virtual const char *getPassName() const {
59 return "Mips Assembly Printer";
62 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
63 unsigned AsmVariant, const char *ExtraCode);
64 void printOperand(const MachineInstr *MI, int opNum);
65 void printUnsignedImm(const MachineInstr *MI, int opNum);
66 void printMemOperand(const MachineInstr *MI, int opNum,
67 const char *Modifier = 0);
68 void printFCCOperand(const MachineInstr *MI, int opNum,
69 const char *Modifier = 0);
70 void printModuleLevelGV(const GlobalVariable* GVar);
71 void printSavedRegsBitmask(MachineFunction &MF);
72 void printHex32(unsigned int Value);
74 const char *emitCurrentABIString(void);
75 void emitFunctionStart(MachineFunction &MF);
76 void emitFunctionEnd(MachineFunction &MF);
77 void emitFrameDirective(MachineFunction &MF);
79 bool printInstruction(const MachineInstr *MI); // autogenerated.
80 bool runOnMachineFunction(MachineFunction &F);
81 bool doInitialization(Module &M);
82 bool doFinalization(Module &M);
84 } // end of anonymous namespace
86 #include "MipsGenAsmWriter.inc"
88 /// createMipsCodePrinterPass - Returns a pass that prints the MIPS
89 /// assembly code for a MachineFunction to the given output stream,
90 /// using the given target machine description. This should work
91 /// regardless of whether the function is in SSA form.
92 FunctionPass *llvm::createMipsCodePrinterPass(raw_ostream &o,
93 MipsTargetMachine &tm)
95 return new MipsAsmPrinter(o, tm, tm.getTargetAsmInfo());
98 //===----------------------------------------------------------------------===//
100 // Mips Asm Directives
102 // -- Frame directive "frame Stackpointer, Stacksize, RARegister"
103 // Describe the stack frame.
105 // -- Mask directives "(f)mask bitmask, offset"
106 // Tells the assembler which registers are saved and where.
107 // bitmask - contain a little endian bitset indicating which registers are
108 // saved on function prologue (e.g. with a 0x80000000 mask, the
109 // assembler knows the register 31 (RA) is saved at prologue.
110 // offset - the position before stack pointer subtraction indicating where
111 // the first saved register on prologue is located. (e.g. with a
113 // Consider the following function prologue:
116 // .mask 0xc0000000,-8
117 // addiu $sp, $sp, -48
121 // With a 0xc0000000 mask, the assembler knows the register 31 (RA) and
122 // 30 (FP) are saved at prologue. As the save order on prologue is from
123 // left to right, RA is saved first. A -8 offset means that after the
124 // stack pointer subtration, the first register in the mask (RA) will be
125 // saved at address 48-8=40.
127 //===----------------------------------------------------------------------===//
129 //===----------------------------------------------------------------------===//
131 //===----------------------------------------------------------------------===//
133 // Create a bitmask with all callee saved registers for CPU or Floating Point
134 // registers. For CPU registers consider RA, GP and FP for saving if necessary.
135 void MipsAsmPrinter::
136 printSavedRegsBitmask(MachineFunction &MF)
138 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
139 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
141 // CPU and FPU Saved Registers Bitmasks
142 unsigned int CPUBitmask = 0;
143 unsigned int FPUBitmask = 0;
145 // Set the CPU and FPU Bitmasks
146 MachineFrameInfo *MFI = MF.getFrameInfo();
147 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
148 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
149 unsigned RegNum = MipsRegisterInfo::getRegisterNumbering(CSI[i].getReg());
150 if (CSI[i].getRegClass() == Mips::CPURegsRegisterClass)
151 CPUBitmask |= (1 << RegNum);
153 FPUBitmask |= (1 << RegNum);
156 // Return Address and Frame registers must also be set in CPUBitmask.
158 CPUBitmask |= (1 << MipsRegisterInfo::
159 getRegisterNumbering(RI.getFrameRegister(MF)));
161 if (MF.getFrameInfo()->hasCalls())
162 CPUBitmask |= (1 << MipsRegisterInfo::
163 getRegisterNumbering(RI.getRARegister()));
166 O << "\t.mask \t"; printHex32(CPUBitmask); O << ','
167 << MipsFI->getCPUTopSavedRegOff() << '\n';
170 O << "\t.fmask\t"; printHex32(FPUBitmask); O << ","
171 << MipsFI->getFPUTopSavedRegOff() << '\n';
174 // Print a 32 bit hex number with all numbers.
175 void MipsAsmPrinter::
176 printHex32(unsigned int Value)
179 for (int i = 7; i >= 0; i--)
180 O << utohexstr( (Value & (0xF << (i*4))) >> (i*4) );
183 //===----------------------------------------------------------------------===//
184 // Frame and Set directives
185 //===----------------------------------------------------------------------===//
188 void MipsAsmPrinter::
189 emitFrameDirective(MachineFunction &MF)
191 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
193 unsigned stackReg = RI.getFrameRegister(MF);
194 unsigned returnReg = RI.getRARegister();
195 unsigned stackSize = MF.getFrameInfo()->getStackSize();
198 O << "\t.frame\t" << '$' << LowercaseString(RI.get(stackReg).AsmName)
199 << ',' << stackSize << ','
200 << '$' << LowercaseString(RI.get(returnReg).AsmName)
204 /// Emit Set directives.
205 const char * MipsAsmPrinter::
206 emitCurrentABIString(void)
208 switch(Subtarget->getTargetABI()) {
209 case MipsSubtarget::O32: return "abi32";
210 case MipsSubtarget::O64: return "abiO64";
211 case MipsSubtarget::N32: return "abiN32";
212 case MipsSubtarget::N64: return "abi64";
213 case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64
217 assert(0 && "Unknown Mips ABI");
221 /// Emit the directives used by GAS on the start of functions
222 void MipsAsmPrinter::
223 emitFunctionStart(MachineFunction &MF)
225 // Print out the label for the function.
226 const Function *F = MF.getFunction();
227 SwitchToSection(TAI->SectionForGlobal(F));
232 O << "\t.globl\t" << CurrentFnName << '\n';
233 O << "\t.ent\t" << CurrentFnName << '\n';
235 printVisibility(CurrentFnName, F->getVisibility());
237 if ((TAI->hasDotTypeDotSizeDirective()) && Subtarget->isLinux())
238 O << "\t.type\t" << CurrentFnName << ", @function\n";
240 O << CurrentFnName << ":\n";
242 emitFrameDirective(MF);
243 printSavedRegsBitmask(MF);
248 /// Emit the directives used by GAS on the end of functions
249 void MipsAsmPrinter::
250 emitFunctionEnd(MachineFunction &MF)
252 // There are instruction for this macros, but they must
253 // always be at the function end, and we can't emit and
254 // break with BB logic.
255 O << "\t.set\tmacro\n";
256 O << "\t.set\treorder\n";
258 O << "\t.end\t" << CurrentFnName << '\n';
259 if (TAI->hasDotTypeDotSizeDirective() && !Subtarget->isLinux())
260 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << '\n';
263 /// runOnMachineFunction - This uses the printMachineInstruction()
264 /// method to print assembly for each instruction.
265 bool MipsAsmPrinter::
266 runOnMachineFunction(MachineFunction &MF)
268 SetupMachineFunction(MF);
270 // Print out constants referenced by the function
271 EmitConstantPool(MF.getConstantPool());
273 // Print out jump tables referenced by the function
274 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
278 // What's my mangled name?
279 CurrentFnName = Mang->getValueName(MF.getFunction());
281 // Emit the function start directives
282 emitFunctionStart(MF);
284 // Print out code for the function.
285 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
288 // Print a label for the basic block.
289 if (I != MF.begin()) {
290 printBasicBlockLabel(I, true, true);
294 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
296 // Print the assembly for the instruction.
297 printInstruction(II);
301 // Each Basic Block is separated by a newline
305 // Emit function end directives
308 // We didn't modify anything.
312 // Print out an operand for an inline asm expression.
313 bool MipsAsmPrinter::
314 PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
315 unsigned AsmVariant, const char *ExtraCode)
317 // Does this asm operand have a single letter operand modifier?
318 if (ExtraCode && ExtraCode[0])
319 return true; // Unknown modifier.
321 printOperand(MI, OpNo);
325 void MipsAsmPrinter::
326 printOperand(const MachineInstr *MI, int opNum)
328 const MachineOperand &MO = MI->getOperand(opNum);
329 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
331 bool isPIC = (TM.getRelocationModel() == Reloc::PIC_);
332 bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
334 // %hi and %lo used on mips gas to load global addresses on
335 // static code. %got is used to load global addresses when
336 // using PIC_. %call16 is used to load direct call targets
337 // on PIC_ and small code size. %call_lo and %call_hi load
338 // direct call targets on PIC_ and large code size.
339 if (MI->getOpcode() == Mips::LUi && !MO.isReg() && !MO.isImm()) {
340 if ((isPIC) && (isCodeLarge))
345 } else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isReg() && !MO.isImm()) {
346 const MachineOperand &firstMO = MI->getOperand(opNum-1);
347 if (firstMO.getReg() == Mips::GP)
352 } else if ((isPIC) && (MI->getOpcode() == Mips::LW) &&
353 (!MO.isReg()) && (!MO.isImm())) {
354 const MachineOperand &firstMO = MI->getOperand(opNum-1);
355 const MachineOperand &lastMO = MI->getOperand(opNum+1);
356 if ((firstMO.isReg()) && (lastMO.isReg())) {
357 if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() == Mips::GP)
360 else if ((firstMO.getReg() != Mips::T9) && (lastMO.getReg() == Mips::GP))
362 else if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() != Mips::GP)
369 switch (MO.getType())
371 case MachineOperand::MO_Register:
372 if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
373 O << '$' << LowercaseString (RI.get(MO.getReg()).AsmName);
375 O << '$' << MO.getReg();
378 case MachineOperand::MO_Immediate:
379 O << (short int)MO.getImm();
382 case MachineOperand::MO_MachineBasicBlock:
383 printBasicBlockLabel(MO.getMBB());
386 case MachineOperand::MO_GlobalAddress:
387 O << Mang->getValueName(MO.getGlobal());
390 case MachineOperand::MO_ExternalSymbol:
391 O << MO.getSymbolName();
394 case MachineOperand::MO_JumpTableIndex:
395 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
396 << '_' << MO.getIndex();
399 case MachineOperand::MO_ConstantPoolIndex:
400 O << TAI->getPrivateGlobalPrefix() << "CPI"
401 << getFunctionNumber() << "_" << MO.getIndex();
405 O << "<unknown operand type>"; abort (); break;
408 if (closeP) O << ")";
411 void MipsAsmPrinter::
412 printUnsignedImm(const MachineInstr *MI, int opNum)
414 const MachineOperand &MO = MI->getOperand(opNum);
415 if (MO.getType() == MachineOperand::MO_Immediate)
416 O << (unsigned short int)MO.getImm();
418 printOperand(MI, opNum);
421 void MipsAsmPrinter::
422 printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier)
424 // when using stack locations for not load/store instructions
425 // print the same way as all normal 3 operand instructions.
426 if (Modifier && !strcmp(Modifier, "stackloc")) {
427 printOperand(MI, opNum+1);
429 printOperand(MI, opNum);
433 // Load/Store memory operands -- imm($reg)
434 // If PIC target the target is loaded as the
435 // pattern lw $25,%call16($28)
436 printOperand(MI, opNum);
438 printOperand(MI, opNum+1);
442 void MipsAsmPrinter::
443 printFCCOperand(const MachineInstr *MI, int opNum, const char *Modifier)
445 const MachineOperand& MO = MI->getOperand(opNum);
446 O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm());
449 bool MipsAsmPrinter::
450 doInitialization(Module &M)
452 Mang = new Mangler(M);
454 // Tell the assembler which ABI we are using
455 O << "\t.section .mdebug." << emitCurrentABIString() << '\n';
457 // TODO: handle O64 ABI
458 if (Subtarget->isABI_EABI())
459 O << "\t.section .gcc_compiled_long" <<
460 (Subtarget->isGP32bit() ? "32" : "64") << '\n';
462 // return to previous section
463 O << "\t.previous" << '\n';
465 return false; // success
468 void MipsAsmPrinter::
469 printModuleLevelGV(const GlobalVariable* GVar) {
470 const TargetData *TD = TM.getTargetData();
472 if (!GVar->hasInitializer())
473 return; // External global require no code
475 // Check to see if this is a special global used by LLVM, if so, emit it.
476 if (EmitSpecialLLVMGlobal(GVar))
480 std::string name = Mang->getValueName(GVar);
481 Constant *C = GVar->getInitializer();
482 const Type *CTy = C->getType();
483 unsigned Size = TD->getABITypeSize(CTy);
484 const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
485 bool printSizeAndType = true;
487 // A data structure or array is aligned in memory to the largest
488 // alignment boundary required by any data type inside it (this matches
489 // the Preferred Type Alignment). For integral types, the alignment is
492 if (CTy->getTypeID() == Type::IntegerTyID ||
493 CTy->getTypeID() == Type::VoidTyID) {
494 assert(!(Size & (Size-1)) && "Alignment is not a power of two!");
495 Align = Log2_32(Size);
497 Align = TD->getPreferredTypeAlignmentShift(CTy);
499 printVisibility(name, GVar->getVisibility());
501 SwitchToSection(TAI->SectionForGlobal(GVar));
503 if (C->isNullValue() && !GVar->hasSection()) {
504 if (!GVar->isThreadLocal() &&
505 (GVar->hasInternalLinkage() || GVar->mayBeOverridden())) {
506 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
508 if (GVar->hasInternalLinkage())
509 O << "\t.local\t" << name << '\n';
511 O << TAI->getCOMMDirective() << name << ',' << Size;
512 if (TAI->getCOMMDirectiveTakesAlignment())
513 O << ',' << (1 << Align);
519 switch (GVar->getLinkage()) {
520 case GlobalValue::LinkOnceLinkage:
521 case GlobalValue::CommonLinkage:
522 case GlobalValue::WeakLinkage:
523 // FIXME: Verify correct for weak.
524 // Nonnull linkonce -> weak
525 O << "\t.weak " << name << '\n';
527 case GlobalValue::AppendingLinkage:
528 // FIXME: appending linkage variables should go into a section of their name
529 // or something. For now, just emit them as external.
530 case GlobalValue::ExternalLinkage:
531 // If external or appending, declare as a global symbol
532 O << TAI->getGlobalDirective() << name << '\n';
534 case GlobalValue::InternalLinkage:
535 if (CVA && CVA->isCString())
536 printSizeAndType = false;
538 case GlobalValue::GhostLinkage:
539 cerr << "Should not have any unmaterialized functions!\n";
541 case GlobalValue::DLLImportLinkage:
542 cerr << "DLLImport linkage is not supported by this target!\n";
544 case GlobalValue::DLLExportLinkage:
545 cerr << "DLLExport linkage is not supported by this target!\n";
548 assert(0 && "Unknown linkage type!");
551 EmitAlignment(Align, GVar);
553 if (TAI->hasDotTypeDotSizeDirective() && printSizeAndType) {
554 O << "\t.type " << name << ",@object\n";
555 O << "\t.size " << name << ',' << Size << '\n';
559 EmitGlobalConstant(C);
562 bool MipsAsmPrinter::
563 doFinalization(Module &M)
565 // Print out module-level global variables here.
566 for (Module::const_global_iterator I = M.global_begin(),
567 E = M.global_end(); I != E; ++I)
568 printModuleLevelGV(I);
572 return AsmPrinter::doFinalization(M);