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"
44 STATISTIC(EmittedInsts, "Number of machine instrs printed");
47 struct VISIBILITY_HIDDEN MipsAsmPrinter : public AsmPrinter {
49 const MipsSubtarget *Subtarget;
51 MipsAsmPrinter(std::ostream &O, MipsTargetMachine &TM,
52 const TargetAsmInfo *T):
53 AsmPrinter(O, TM, T) {
54 Subtarget = &TM.getSubtarget<MipsSubtarget>();
57 virtual const char *getPassName() const {
58 return "Mips Assembly Printer";
61 virtual std::string getSectionForFunction(const Function &F) const;
62 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
63 unsigned AsmVariant, const char *ExtraCode);
64 void printOperand(const MachineInstr *MI, int opNum);
65 void printMemOperand(const MachineInstr *MI, int opNum,
66 const char *Modifier = 0);
67 void printFCCOperand(const MachineInstr *MI, int opNum,
68 const char *Modifier = 0);
69 void printModuleLevelGV(const GlobalVariable* GVar);
70 void printSavedRegsBitmask(MachineFunction &MF);
71 void printHex32(unsigned int Value);
73 const char *emitCurrentABIString(void);
74 void emitFunctionStart(MachineFunction &MF);
75 void emitFunctionEnd(MachineFunction &MF);
76 void emitFrameDirective(MachineFunction &MF);
78 bool printInstruction(const MachineInstr *MI); // autogenerated.
79 bool runOnMachineFunction(MachineFunction &F);
80 bool doInitialization(Module &M);
81 bool doFinalization(Module &M);
83 } // end of anonymous namespace
85 #include "MipsGenAsmWriter.inc"
87 /// createMipsCodePrinterPass - Returns a pass that prints the MIPS
88 /// assembly code for a MachineFunction to the given output stream,
89 /// using the given target machine description. This should work
90 /// regardless of whether the function is in SSA form.
91 FunctionPass *llvm::createMipsCodePrinterPass(std::ostream &o,
92 MipsTargetMachine &tm)
94 return new MipsAsmPrinter(o, tm, tm.getTargetAsmInfo());
97 //===----------------------------------------------------------------------===//
99 // Mips Asm Directives
101 // -- Frame directive "frame Stackpointer, Stacksize, RARegister"
102 // Describe the stack frame.
104 // -- Mask directives "(f)mask bitmask, offset"
105 // Tells the assembler which registers are saved and where.
106 // bitmask - contain a little endian bitset indicating which registers are
107 // saved on function prologue (e.g. with a 0x80000000 mask, the
108 // assembler knows the register 31 (RA) is saved at prologue.
109 // offset - the position before stack pointer subtraction indicating where
110 // the first saved register on prologue is located. (e.g. with a
112 // Consider the following function prologue:
115 // .mask 0xc0000000,-8
116 // addiu $sp, $sp, -48
120 // With a 0xc0000000 mask, the assembler knows the register 31 (RA) and
121 // 30 (FP) are saved at prologue. As the save order on prologue is from
122 // left to right, RA is saved first. A -8 offset means that after the
123 // stack pointer subtration, the first register in the mask (RA) will be
124 // saved at address 48-8=40.
126 //===----------------------------------------------------------------------===//
128 //===----------------------------------------------------------------------===//
130 //===----------------------------------------------------------------------===//
132 // Create a bitmask with all callee saved registers for CPU or Floating Point
133 // registers. For CPU registers consider RA, GP and FP for saving if necessary.
134 void MipsAsmPrinter::
135 printSavedRegsBitmask(MachineFunction &MF)
137 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
138 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
140 // CPU and FPU Saved Registers Bitmasks
141 unsigned int CPUBitmask = 0;
142 unsigned int FPUBitmask = 0;
144 // Set the CPU and FPU Bitmasks
145 MachineFrameInfo *MFI = MF.getFrameInfo();
146 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
147 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
148 unsigned RegNum = MipsRegisterInfo::getRegisterNumbering(CSI[i].getReg());
149 if (CSI[i].getRegClass() == Mips::CPURegsRegisterClass)
150 CPUBitmask |= (1 << RegNum);
152 FPUBitmask |= (1 << RegNum);
155 // Return Address and Frame registers must also be set in CPUBitmask.
157 CPUBitmask |= (1 << MipsRegisterInfo::
158 getRegisterNumbering(RI.getFrameRegister(MF)));
160 if (MF.getFrameInfo()->hasCalls())
161 CPUBitmask |= (1 << MipsRegisterInfo::
162 getRegisterNumbering(RI.getRARegister()));
165 O << "\t.mask \t"; printHex32(CPUBitmask); O << ','
166 << MipsFI->getCPUTopSavedRegOff() << '\n';
169 O << "\t.fmask\t"; printHex32(FPUBitmask); O << ","
170 << MipsFI->getFPUTopSavedRegOff() << '\n';
173 // Print a 32 bit hex number with all numbers.
174 void MipsAsmPrinter::
175 printHex32(unsigned int Value)
177 O << "0x" << std::hex;
178 for (int i = 7; i >= 0; i--)
179 O << std::hex << ( (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 // Substitute old hook with new one temporary
222 std::string MipsAsmPrinter::getSectionForFunction(const Function &F) const {
223 return TAI->SectionForGlobal(&F);
226 /// Emit the directives used by GAS on the start of functions
227 void MipsAsmPrinter::
228 emitFunctionStart(MachineFunction &MF)
230 // Print out the label for the function.
231 const Function *F = MF.getFunction();
232 SwitchToTextSection(TAI->SectionForGlobal(F).c_str());
237 O << "\t.globl\t" << CurrentFnName << '\n';
238 O << "\t.ent\t" << CurrentFnName << '\n';
240 printVisibility(CurrentFnName, F->getVisibility());
242 if ((TAI->hasDotTypeDotSizeDirective()) && Subtarget->isLinux())
243 O << "\t.type\t" << CurrentFnName << ", @function\n";
245 O << CurrentFnName << ":\n";
247 emitFrameDirective(MF);
248 printSavedRegsBitmask(MF);
253 /// Emit the directives used by GAS on the end of functions
254 void MipsAsmPrinter::
255 emitFunctionEnd(MachineFunction &MF)
257 // There are instruction for this macros, but they must
258 // always be at the function end, and we can't emit and
259 // break with BB logic.
260 O << "\t.set\tmacro\n";
261 O << "\t.set\treorder\n";
263 O << "\t.end\t" << CurrentFnName << '\n';
264 if (TAI->hasDotTypeDotSizeDirective() && !Subtarget->isLinux())
265 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << '\n';
268 /// runOnMachineFunction - This uses the printMachineInstruction()
269 /// method to print assembly for each instruction.
270 bool MipsAsmPrinter::
271 runOnMachineFunction(MachineFunction &MF)
273 SetupMachineFunction(MF);
275 // Print out constants referenced by the function
276 EmitConstantPool(MF.getConstantPool());
278 // Print out jump tables referenced by the function
279 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
283 // What's my mangled name?
284 CurrentFnName = Mang->getValueName(MF.getFunction());
286 // Emit the function start directives
287 emitFunctionStart(MF);
289 // Print out code for the function.
290 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
293 // Print a label for the basic block.
294 if (I != MF.begin()) {
295 printBasicBlockLabel(I, true, true);
299 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
301 // Print the assembly for the instruction.
302 printInstruction(II);
306 // Each Basic Block is separated by a newline
310 // Emit function end directives
313 // We didn't modify anything.
317 // Print out an operand for an inline asm expression.
318 bool MipsAsmPrinter::
319 PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
320 unsigned AsmVariant, const char *ExtraCode)
322 // Does this asm operand have a single letter operand modifier?
323 if (ExtraCode && ExtraCode[0])
324 return true; // Unknown modifier.
326 printOperand(MI, OpNo);
330 void MipsAsmPrinter::
331 printOperand(const MachineInstr *MI, int opNum)
333 const MachineOperand &MO = MI->getOperand(opNum);
334 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
336 bool isPIC = (TM.getRelocationModel() == Reloc::PIC_);
337 bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
339 // %hi and %lo used on mips gas to load global addresses on
340 // static code. %got is used to load global addresses when
341 // using PIC_. %call16 is used to load direct call targets
342 // on PIC_ and small code size. %call_lo and %call_hi load
343 // direct call targets on PIC_ and large code size.
344 if (MI->getOpcode() == Mips::LUi && !MO.isRegister()
345 && !MO.isImmediate()) {
346 if ((isPIC) && (isCodeLarge))
351 } else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isRegister()
352 && !MO.isImmediate()) {
353 const MachineOperand &firstMO = MI->getOperand(opNum-1);
354 if (firstMO.getReg() == Mips::GP)
359 } else if ((isPIC) && (MI->getOpcode() == Mips::LW)
360 && (!MO.isRegister()) && (!MO.isImmediate())) {
361 const MachineOperand &firstMO = MI->getOperand(opNum-1);
362 const MachineOperand &lastMO = MI->getOperand(opNum+1);
363 if ((firstMO.isRegister()) && (lastMO.isRegister())) {
364 if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() == Mips::GP)
367 else if ((firstMO.getReg() != Mips::T9) && (lastMO.getReg() == Mips::GP))
369 else if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() != Mips::GP)
376 switch (MO.getType())
378 case MachineOperand::MO_Register:
379 if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
380 O << '$' << LowercaseString (RI.get(MO.getReg()).AsmName);
382 O << '$' << MO.getReg();
385 case MachineOperand::MO_Immediate:
386 if ((MI->getOpcode() == Mips::SLTiu) || (MI->getOpcode() == Mips::ORi) ||
387 (MI->getOpcode() == Mips::LUi) || (MI->getOpcode() == Mips::ANDi))
388 O << (unsigned short int)MO.getImm();
390 O << (short int)MO.getImm();
393 case MachineOperand::MO_MachineBasicBlock:
394 printBasicBlockLabel(MO.getMBB());
397 case MachineOperand::MO_GlobalAddress:
398 O << Mang->getValueName(MO.getGlobal());
401 case MachineOperand::MO_ExternalSymbol:
402 O << MO.getSymbolName();
405 case MachineOperand::MO_JumpTableIndex:
406 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
407 << '_' << MO.getIndex();
410 // FIXME: Verify correct
411 case MachineOperand::MO_ConstantPoolIndex:
412 O << TAI->getPrivateGlobalPrefix() << "CPI"
413 << getFunctionNumber() << "_" << MO.getIndex();
417 O << "<unknown operand type>"; abort (); break;
420 if (closeP) O << ")";
423 void MipsAsmPrinter::
424 printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier)
426 // when using stack locations for not load/store instructions
427 // print the same way as all normal 3 operand instructions.
428 if (Modifier && !strcmp(Modifier, "stackloc")) {
429 printOperand(MI, opNum+1);
431 printOperand(MI, opNum);
435 // Load/Store memory operands -- imm($reg)
436 // If PIC target the target is loaded as the
437 // pattern lw $25,%call16($28)
438 printOperand(MI, opNum);
440 printOperand(MI, opNum+1);
444 void MipsAsmPrinter::
445 printFCCOperand(const MachineInstr *MI, int opNum, const char *Modifier)
447 const MachineOperand& MO = MI->getOperand(opNum);
448 O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm());
451 bool MipsAsmPrinter::
452 doInitialization(Module &M)
454 Mang = new Mangler(M);
456 // Tell the assembler which ABI we are using
457 O << "\t.section .mdebug." << emitCurrentABIString() << '\n';
459 // TODO: handle O64 ABI
460 if (Subtarget->isABI_EABI())
461 O << "\t.section .gcc_compiled_long" <<
462 (Subtarget->isGP32bit() ? "32" : "64") << '\n';
464 // return to previous section
465 O << "\t.previous" << '\n';
467 return false; // success
470 void MipsAsmPrinter::
471 printModuleLevelGV(const GlobalVariable* GVar) {
472 const TargetData *TD = TM.getTargetData();
474 if (!GVar->hasInitializer())
475 return; // External global require no code
477 // Check to see if this is a special global used by LLVM, if so, emit it.
478 if (EmitSpecialLLVMGlobal(GVar))
482 std::string SectionName = TAI->SectionForGlobal(GVar);
483 std::string name = Mang->getValueName(GVar);
484 Constant *C = GVar->getInitializer();
485 const Type *CTy = C->getType();
486 unsigned Size = TD->getABITypeSize(CTy);
487 const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
488 bool printSizeAndType = true;
490 // A data structure or array is aligned in memory to the largest
491 // alignment boundary required by any data type inside it (this matches
492 // the Preferred Type Alignment). For integral types, the alignment is
495 if (CTy->getTypeID() == Type::IntegerTyID ||
496 CTy->getTypeID() == Type::VoidTyID) {
497 assert(!(Size & (Size-1)) && "Alignment is not a power of two!");
498 Align = Log2_32(Size);
500 Align = TD->getPreferredTypeAlignmentShift(CTy);
502 printVisibility(name, GVar->getVisibility());
504 SwitchToDataSection(SectionName.c_str());
506 if (C->isNullValue() && !GVar->hasSection()) {
507 if (!GVar->isThreadLocal() &&
508 (GVar->hasInternalLinkage() || GVar->isWeakForLinker())) {
509 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
511 if (GVar->hasInternalLinkage())
512 O << "\t.local\t" << name << '\n';
514 O << TAI->getCOMMDirective() << name << ',' << Size;
515 if (TAI->getCOMMDirectiveTakesAlignment())
516 O << ',' << (1 << Align);
522 switch (GVar->getLinkage()) {
523 case GlobalValue::LinkOnceLinkage:
524 case GlobalValue::CommonLinkage:
525 case GlobalValue::WeakLinkage:
526 // FIXME: Verify correct for weak.
527 // Nonnull linkonce -> weak
528 O << "\t.weak " << name << '\n';
530 case GlobalValue::AppendingLinkage:
531 // FIXME: appending linkage variables should go into a section of their name
532 // or something. For now, just emit them as external.
533 case GlobalValue::ExternalLinkage:
534 // If external or appending, declare as a global symbol
535 O << TAI->getGlobalDirective() << name << '\n';
537 case GlobalValue::InternalLinkage:
538 if (CVA && CVA->isCString())
539 printSizeAndType = false;
541 case GlobalValue::GhostLinkage:
542 cerr << "Should not have any unmaterialized functions!\n";
544 case GlobalValue::DLLImportLinkage:
545 cerr << "DLLImport linkage is not supported by this target!\n";
547 case GlobalValue::DLLExportLinkage:
548 cerr << "DLLExport linkage is not supported by this target!\n";
551 assert(0 && "Unknown linkage type!");
554 EmitAlignment(Align, GVar);
556 if (TAI->hasDotTypeDotSizeDirective() && printSizeAndType) {
557 O << "\t.type " << name << ",@object\n";
558 O << "\t.size " << name << ',' << Size << '\n';
562 EmitGlobalConstant(C);
565 bool MipsAsmPrinter::
566 doFinalization(Module &M)
568 // Print out module-level global variables here.
569 for (Module::const_global_iterator I = M.global_begin(),
570 E = M.global_end(); I != E; ++I)
571 printModuleLevelGV(I);
575 return AsmPrinter::doFinalization(M);