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 if ((TAI->hasDotTypeDotSizeDirective()) && Subtarget->isLinux())
241 O << "\t.type\t" << CurrentFnName << ", @function\n";
243 O << CurrentFnName << ":\n";
245 emitFrameDirective(MF);
246 printSavedRegsBitmask(MF);
251 /// Emit the directives used by GAS on the end of functions
252 void MipsAsmPrinter::
253 emitFunctionEnd(MachineFunction &MF)
255 // There are instruction for this macros, but they must
256 // always be at the function end, and we can't emit and
257 // break with BB logic.
258 O << "\t.set\tmacro\n";
259 O << "\t.set\treorder\n";
261 O << "\t.end\t" << CurrentFnName << '\n';
262 if (TAI->hasDotTypeDotSizeDirective() && !Subtarget->isLinux())
263 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << '\n';
266 /// runOnMachineFunction - This uses the printMachineInstruction()
267 /// method to print assembly for each instruction.
268 bool MipsAsmPrinter::
269 runOnMachineFunction(MachineFunction &MF)
271 SetupMachineFunction(MF);
273 // Print out constants referenced by the function
274 EmitConstantPool(MF.getConstantPool());
276 // Print out jump tables referenced by the function
277 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
281 // What's my mangled name?
282 CurrentFnName = Mang->getValueName(MF.getFunction());
284 // Emit the function start directives
285 emitFunctionStart(MF);
287 // Print out code for the function.
288 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
291 // Print a label for the basic block.
292 if (I != MF.begin()) {
293 printBasicBlockLabel(I, true, true);
297 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
299 // Print the assembly for the instruction.
300 printInstruction(II);
304 // Each Basic Block is separated by a newline
308 // Emit function end directives
311 // We didn't modify anything.
315 // Print out an operand for an inline asm expression.
316 bool MipsAsmPrinter::
317 PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
318 unsigned AsmVariant, const char *ExtraCode)
320 // Does this asm operand have a single letter operand modifier?
321 if (ExtraCode && ExtraCode[0])
322 return true; // Unknown modifier.
324 printOperand(MI, OpNo);
328 void MipsAsmPrinter::
329 printOperand(const MachineInstr *MI, int opNum)
331 const MachineOperand &MO = MI->getOperand(opNum);
332 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
334 bool isPIC = (TM.getRelocationModel() == Reloc::PIC_);
335 bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
337 // %hi and %lo used on mips gas to load global addresses on
338 // static code. %got is used to load global addresses when
339 // using PIC_. %call16 is used to load direct call targets
340 // on PIC_ and small code size. %call_lo and %call_hi load
341 // direct call targets on PIC_ and large code size.
342 if (MI->getOpcode() == Mips::LUi && !MO.isRegister()
343 && !MO.isImmediate()) {
344 if ((isPIC) && (isCodeLarge))
349 } else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isRegister()
350 && !MO.isImmediate()) {
351 const MachineOperand &firstMO = MI->getOperand(opNum-1);
352 if (firstMO.getReg() == Mips::GP)
357 } else if ((isPIC) && (MI->getOpcode() == Mips::LW)
358 && (!MO.isRegister()) && (!MO.isImmediate())) {
359 const MachineOperand &firstMO = MI->getOperand(opNum-1);
360 const MachineOperand &lastMO = MI->getOperand(opNum+1);
361 if ((firstMO.isRegister()) && (lastMO.isRegister())) {
362 if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() == Mips::GP)
365 else if ((firstMO.getReg() != Mips::T9) && (lastMO.getReg() == Mips::GP))
367 else if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() != Mips::GP)
374 switch (MO.getType())
376 case MachineOperand::MO_Register:
377 if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
378 O << '$' << LowercaseString (RI.get(MO.getReg()).AsmName);
380 O << '$' << MO.getReg();
383 case MachineOperand::MO_Immediate:
384 if ((MI->getOpcode() == Mips::SLTiu) || (MI->getOpcode() == Mips::ORi) ||
385 (MI->getOpcode() == Mips::LUi) || (MI->getOpcode() == Mips::ANDi))
386 O << (unsigned short int)MO.getImm();
388 O << (short int)MO.getImm();
391 case MachineOperand::MO_MachineBasicBlock:
392 printBasicBlockLabel(MO.getMBB());
395 case MachineOperand::MO_GlobalAddress:
396 O << Mang->getValueName(MO.getGlobal());
399 case MachineOperand::MO_ExternalSymbol:
400 O << MO.getSymbolName();
403 case MachineOperand::MO_JumpTableIndex:
404 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
405 << '_' << MO.getIndex();
408 // FIXME: Verify correct
409 case MachineOperand::MO_ConstantPoolIndex:
410 O << TAI->getPrivateGlobalPrefix() << "CPI"
411 << getFunctionNumber() << "_" << MO.getIndex();
415 O << "<unknown operand type>"; abort (); break;
418 if (closeP) O << ")";
421 void MipsAsmPrinter::
422 printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier)
424 // when using stack locations for not load/store instructions
425 // print the same way as all normal 3 operand instructions.
426 if (Modifier && !strcmp(Modifier, "stackloc")) {
427 printOperand(MI, opNum+1);
429 printOperand(MI, opNum);
433 // Load/Store memory operands -- imm($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 SectionName = TAI->SectionForGlobal(GVar);
481 std::string name = Mang->getValueName(GVar);
482 Constant *C = GVar->getInitializer();
483 const Type *CTy = C->getType();
484 unsigned Size = TD->getABITypeSize(CTy);
485 const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
486 bool printSizeAndType = true;
488 // A data structure or array is aligned in memory to the largest
489 // alignment boundary required by any data type inside it (this matches
490 // the Preferred Type Alignment). For integral types, the alignment is
493 if (CTy->getTypeID() == Type::IntegerTyID ||
494 CTy->getTypeID() == Type::VoidTyID) {
495 assert(!(Size & (Size-1)) && "Alignment is not a power of two!");
496 Align = Log2_32(Size);
498 Align = TD->getPreferredTypeAlignmentShift(CTy);
500 // FIXME: ELF supports visibility
502 SwitchToDataSection(SectionName.c_str());
504 if (C->isNullValue() && !GVar->hasSection()) {
505 if (!GVar->isThreadLocal() &&
506 (GVar->hasInternalLinkage() || GVar->isWeakForLinker())) {
507 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
509 if (GVar->hasInternalLinkage())
510 O << "\t.local\t" << name << '\n';
512 O << TAI->getCOMMDirective() << name << ',' << Size;
513 if (TAI->getCOMMDirectiveTakesAlignment())
514 O << ',' << (1 << Align);
520 switch (GVar->getLinkage()) {
521 case GlobalValue::LinkOnceLinkage:
522 case GlobalValue::CommonLinkage:
523 case GlobalValue::WeakLinkage:
524 // FIXME: Verify correct for weak.
525 // Nonnull linkonce -> weak
526 O << "\t.weak " << name << '\n';
528 case GlobalValue::AppendingLinkage:
529 // FIXME: appending linkage variables should go into a section of their name
530 // or something. For now, just emit them as external.
531 case GlobalValue::ExternalLinkage:
532 // If external or appending, declare as a global symbol
533 O << TAI->getGlobalDirective() << name << '\n';
535 case GlobalValue::InternalLinkage:
536 if (CVA && CVA->isCString())
537 printSizeAndType = false;
539 case GlobalValue::GhostLinkage:
540 cerr << "Should not have any unmaterialized functions!\n";
542 case GlobalValue::DLLImportLinkage:
543 cerr << "DLLImport linkage is not supported by this target!\n";
545 case GlobalValue::DLLExportLinkage:
546 cerr << "DLLExport linkage is not supported by this target!\n";
549 assert(0 && "Unknown linkage type!");
553 O << "\t.align " << Align << '\n';
555 if (TAI->hasDotTypeDotSizeDirective() && printSizeAndType) {
556 O << "\t.type " << name << ",@object\n";
557 O << "\t.size " << name << ',' << Size << '\n';
561 EmitGlobalConstant(C);
564 bool MipsAsmPrinter::
565 doFinalization(Module &M)
567 // Print out module-level global variables here.
568 for (Module::const_global_iterator I = M.global_begin(),
569 E = M.global_end(); I != E; ++I)
570 printModuleLevelGV(I);
574 return AsmPrinter::doFinalization(M);