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/MDNode.h"
26 #include "llvm/CodeGen/AsmPrinter.h"
27 #include "llvm/CodeGen/DwarfWriter.h"
28 #include "llvm/CodeGen/MachineFunctionPass.h"
29 #include "llvm/CodeGen/MachineConstantPool.h"
30 #include "llvm/CodeGen/MachineFrameInfo.h"
31 #include "llvm/CodeGen/MachineInstr.h"
32 #include "llvm/Target/TargetAsmInfo.h"
33 #include "llvm/Target/TargetData.h"
34 #include "llvm/Target/TargetLoweringObjectFile.h"
35 #include "llvm/Target/TargetMachine.h"
36 #include "llvm/Target/TargetOptions.h"
37 #include "llvm/Target/TargetRegistry.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/Mangler.h"
40 #include "llvm/ADT/Statistic.h"
41 #include "llvm/ADT/StringExtras.h"
42 #include "llvm/Support/Debug.h"
43 #include "llvm/Support/CommandLine.h"
44 #include "llvm/Support/FormattedStream.h"
45 #include "llvm/Support/MathExtras.h"
50 STATISTIC(EmittedInsts, "Number of machine instrs printed");
53 class VISIBILITY_HIDDEN MipsAsmPrinter : public AsmPrinter {
54 const MipsSubtarget *Subtarget;
56 explicit MipsAsmPrinter(formatted_raw_ostream &O, TargetMachine &TM,
57 const TargetAsmInfo *T, bool V)
58 : AsmPrinter(O, TM, T, V) {
59 Subtarget = &TM.getSubtarget<MipsSubtarget>();
62 virtual const char *getPassName() const {
63 return "Mips Assembly Printer";
66 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
67 unsigned AsmVariant, const char *ExtraCode);
68 void printOperand(const MachineInstr *MI, int opNum);
69 void printUnsignedImm(const MachineInstr *MI, int opNum);
70 void printMemOperand(const MachineInstr *MI, int opNum,
71 const char *Modifier = 0);
72 void printFCCOperand(const MachineInstr *MI, int opNum,
73 const char *Modifier = 0);
74 void PrintGlobalVariable(const GlobalVariable *GVar);
75 void printSavedRegsBitmask(MachineFunction &MF);
76 void printHex32(unsigned int Value);
78 const char *emitCurrentABIString(void);
79 void emitFunctionStart(MachineFunction &MF);
80 void emitFunctionEnd(MachineFunction &MF);
81 void emitFrameDirective(MachineFunction &MF);
83 bool printInstruction(const MachineInstr *MI); // autogenerated.
84 bool runOnMachineFunction(MachineFunction &F);
85 bool doInitialization(Module &M);
87 } // end of anonymous namespace
89 #include "MipsGenAsmWriter.inc"
91 //===----------------------------------------------------------------------===//
93 // Mips Asm Directives
95 // -- Frame directive "frame Stackpointer, Stacksize, RARegister"
96 // Describe the stack frame.
98 // -- Mask directives "(f)mask bitmask, offset"
99 // Tells the assembler which registers are saved and where.
100 // bitmask - contain a little endian bitset indicating which registers are
101 // saved on function prologue (e.g. with a 0x80000000 mask, the
102 // assembler knows the register 31 (RA) is saved at prologue.
103 // offset - the position before stack pointer subtraction indicating where
104 // the first saved register on prologue is located. (e.g. with a
106 // Consider the following function prologue:
109 // .mask 0xc0000000,-8
110 // addiu $sp, $sp, -48
114 // With a 0xc0000000 mask, the assembler knows the register 31 (RA) and
115 // 30 (FP) are saved at prologue. As the save order on prologue is from
116 // left to right, RA is saved first. A -8 offset means that after the
117 // stack pointer subtration, the first register in the mask (RA) will be
118 // saved at address 48-8=40.
120 //===----------------------------------------------------------------------===//
122 //===----------------------------------------------------------------------===//
124 //===----------------------------------------------------------------------===//
126 // Create a bitmask with all callee saved registers for CPU or Floating Point
127 // registers. For CPU registers consider RA, GP and FP for saving if necessary.
128 void MipsAsmPrinter::
129 printSavedRegsBitmask(MachineFunction &MF)
131 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
132 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
134 // CPU and FPU Saved Registers Bitmasks
135 unsigned int CPUBitmask = 0;
136 unsigned int FPUBitmask = 0;
138 // Set the CPU and FPU Bitmasks
139 MachineFrameInfo *MFI = MF.getFrameInfo();
140 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
141 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
142 unsigned RegNum = MipsRegisterInfo::getRegisterNumbering(CSI[i].getReg());
143 if (CSI[i].getRegClass() == Mips::CPURegsRegisterClass)
144 CPUBitmask |= (1 << RegNum);
146 FPUBitmask |= (1 << RegNum);
149 // Return Address and Frame registers must also be set in CPUBitmask.
151 CPUBitmask |= (1 << MipsRegisterInfo::
152 getRegisterNumbering(RI.getFrameRegister(MF)));
154 if (MF.getFrameInfo()->hasCalls())
155 CPUBitmask |= (1 << MipsRegisterInfo::
156 getRegisterNumbering(RI.getRARegister()));
159 O << "\t.mask \t"; printHex32(CPUBitmask); O << ','
160 << MipsFI->getCPUTopSavedRegOff() << '\n';
163 O << "\t.fmask\t"; printHex32(FPUBitmask); O << ","
164 << MipsFI->getFPUTopSavedRegOff() << '\n';
167 // Print a 32 bit hex number with all numbers.
168 void MipsAsmPrinter::
169 printHex32(unsigned int Value)
172 for (int i = 7; i >= 0; i--)
173 O << utohexstr( (Value & (0xF << (i*4))) >> (i*4) );
176 //===----------------------------------------------------------------------===//
177 // Frame and Set directives
178 //===----------------------------------------------------------------------===//
181 void MipsAsmPrinter::
182 emitFrameDirective(MachineFunction &MF)
184 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
186 unsigned stackReg = RI.getFrameRegister(MF);
187 unsigned returnReg = RI.getRARegister();
188 unsigned stackSize = MF.getFrameInfo()->getStackSize();
191 O << "\t.frame\t" << '$' << LowercaseString(RI.get(stackReg).AsmName)
192 << ',' << stackSize << ','
193 << '$' << LowercaseString(RI.get(returnReg).AsmName)
197 /// Emit Set directives.
198 const char * MipsAsmPrinter::
199 emitCurrentABIString(void)
201 switch(Subtarget->getTargetABI()) {
202 case MipsSubtarget::O32: return "abi32";
203 case MipsSubtarget::O64: return "abiO64";
204 case MipsSubtarget::N32: return "abiN32";
205 case MipsSubtarget::N64: return "abi64";
206 case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64
210 llvm_unreachable("Unknown Mips ABI");
214 /// Emit the directives used by GAS on the start of functions
215 void MipsAsmPrinter::emitFunctionStart(MachineFunction &MF) {
216 // Print out the label for the function.
217 const Function *F = MF.getFunction();
218 SwitchToSection(getObjFileLowering().SectionForGlobal(F, TM));
221 EmitAlignment(MF.getAlignment(), F);
223 O << "\t.globl\t" << CurrentFnName << '\n';
224 O << "\t.ent\t" << CurrentFnName << '\n';
226 printVisibility(CurrentFnName, F->getVisibility());
228 if ((TAI->hasDotTypeDotSizeDirective()) && Subtarget->isLinux())
229 O << "\t.type\t" << CurrentFnName << ", @function\n";
231 O << CurrentFnName << ":\n";
233 emitFrameDirective(MF);
234 printSavedRegsBitmask(MF);
239 /// Emit the directives used by GAS on the end of functions
240 void MipsAsmPrinter::
241 emitFunctionEnd(MachineFunction &MF)
243 // There are instruction for this macros, but they must
244 // always be at the function end, and we can't emit and
245 // break with BB logic.
246 O << "\t.set\tmacro\n";
247 O << "\t.set\treorder\n";
249 O << "\t.end\t" << CurrentFnName << '\n';
250 if (TAI->hasDotTypeDotSizeDirective() && !Subtarget->isLinux())
251 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << '\n';
254 /// runOnMachineFunction - This uses the printMachineInstruction()
255 /// method to print assembly for each instruction.
256 bool MipsAsmPrinter::
257 runOnMachineFunction(MachineFunction &MF)
261 SetupMachineFunction(MF);
263 // Print out constants referenced by the function
264 EmitConstantPool(MF.getConstantPool());
266 // Print out jump tables referenced by the function
267 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
271 // Emit the function start directives
272 emitFunctionStart(MF);
274 // Print out code for the function.
275 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
278 // Print a label for the basic block.
279 if (I != MF.begin()) {
280 printBasicBlockLabel(I, true, true);
284 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
286 // Print the assembly for the instruction.
287 printInstruction(II);
291 // Each Basic Block is separated by a newline
295 // Emit function end directives
298 // We didn't modify anything.
302 // Print out an operand for an inline asm expression.
303 bool MipsAsmPrinter::
304 PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
305 unsigned AsmVariant, const char *ExtraCode)
307 // Does this asm operand have a single letter operand modifier?
308 if (ExtraCode && ExtraCode[0])
309 return true; // Unknown modifier.
311 printOperand(MI, OpNo);
315 void MipsAsmPrinter::
316 printOperand(const MachineInstr *MI, int opNum)
318 const MachineOperand &MO = MI->getOperand(opNum);
319 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
321 bool isPIC = (TM.getRelocationModel() == Reloc::PIC_);
322 bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
324 // %hi and %lo used on mips gas to load global addresses on
325 // static code. %got is used to load global addresses when
326 // using PIC_. %call16 is used to load direct call targets
327 // on PIC_ and small code size. %call_lo and %call_hi load
328 // direct call targets on PIC_ and large code size.
329 if (MI->getOpcode() == Mips::LUi && !MO.isReg() && !MO.isImm()) {
330 if ((isPIC) && (isCodeLarge))
335 } else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isReg() && !MO.isImm()) {
336 const MachineOperand &firstMO = MI->getOperand(opNum-1);
337 if (firstMO.getReg() == Mips::GP)
342 } else if ((isPIC) && (MI->getOpcode() == Mips::LW) &&
343 (!MO.isReg()) && (!MO.isImm())) {
344 const MachineOperand &firstMO = MI->getOperand(opNum-1);
345 const MachineOperand &lastMO = MI->getOperand(opNum+1);
346 if ((firstMO.isReg()) && (lastMO.isReg())) {
347 if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() == Mips::GP)
350 else if ((firstMO.getReg() != Mips::T9) && (lastMO.getReg() == Mips::GP))
352 else if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() != Mips::GP)
359 switch (MO.getType())
361 case MachineOperand::MO_Register:
362 if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
363 O << '$' << LowercaseString (RI.get(MO.getReg()).AsmName);
365 O << '$' << MO.getReg();
368 case MachineOperand::MO_Immediate:
369 O << (short int)MO.getImm();
372 case MachineOperand::MO_MachineBasicBlock:
373 printBasicBlockLabel(MO.getMBB());
376 case MachineOperand::MO_GlobalAddress:
377 O << Mang->getMangledName(MO.getGlobal());
380 case MachineOperand::MO_ExternalSymbol:
381 O << MO.getSymbolName();
384 case MachineOperand::MO_JumpTableIndex:
385 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
386 << '_' << MO.getIndex();
389 case MachineOperand::MO_ConstantPoolIndex:
390 O << TAI->getPrivateGlobalPrefix() << "CPI"
391 << getFunctionNumber() << "_" << MO.getIndex();
395 llvm_unreachable("<unknown operand type>");
398 if (closeP) O << ")";
401 void MipsAsmPrinter::
402 printUnsignedImm(const MachineInstr *MI, int opNum) {
403 const MachineOperand &MO = MI->getOperand(opNum);
404 if (MO.getType() == MachineOperand::MO_Immediate)
405 O << (unsigned short int)MO.getImm();
407 printOperand(MI, opNum);
410 void MipsAsmPrinter::
411 printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier) {
412 // when using stack locations for not load/store instructions
413 // print the same way as all normal 3 operand instructions.
414 if (Modifier && !strcmp(Modifier, "stackloc")) {
415 printOperand(MI, opNum+1);
417 printOperand(MI, opNum);
421 // Load/Store memory operands -- imm($reg)
422 // If PIC target the target is loaded as the
423 // pattern lw $25,%call16($28)
424 printOperand(MI, opNum);
426 printOperand(MI, opNum+1);
430 void MipsAsmPrinter::
431 printFCCOperand(const MachineInstr *MI, int opNum, const char *Modifier) {
432 const MachineOperand& MO = MI->getOperand(opNum);
433 O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm());
436 bool MipsAsmPrinter::doInitialization(Module &M) {
437 // FIXME: Use SwitchToDataSection.
439 // Tell the assembler which ABI we are using
440 O << "\t.section .mdebug." << emitCurrentABIString() << '\n';
442 // TODO: handle O64 ABI
443 if (Subtarget->isABI_EABI())
444 O << "\t.section .gcc_compiled_long" <<
445 (Subtarget->isGP32bit() ? "32" : "64") << '\n';
447 // return to previous section
448 O << "\t.previous" << '\n';
450 return AsmPrinter::doInitialization(M);
453 void MipsAsmPrinter::PrintGlobalVariable(const GlobalVariable *GVar) {
454 const TargetData *TD = TM.getTargetData();
456 if (!GVar->hasInitializer())
457 return; // External global require no code
459 // Check to see if this is a special global used by LLVM, if so, emit it.
460 if (EmitSpecialLLVMGlobal(GVar))
464 std::string name = Mang->getMangledName(GVar);
465 Constant *C = GVar->getInitializer();
466 if (isa<MDNode>(C) || isa<MDString>(C))
468 const Type *CTy = C->getType();
469 unsigned Size = TD->getTypeAllocSize(CTy);
470 const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
471 bool printSizeAndType = true;
473 // A data structure or array is aligned in memory to the largest
474 // alignment boundary required by any data type inside it (this matches
475 // the Preferred Type Alignment). For integral types, the alignment is
478 if (CTy->getTypeID() == Type::IntegerTyID ||
479 CTy->getTypeID() == Type::VoidTyID) {
480 assert(!(Size & (Size-1)) && "Alignment is not a power of two!");
481 Align = Log2_32(Size);
483 Align = TD->getPreferredTypeAlignmentShift(CTy);
485 printVisibility(name, GVar->getVisibility());
487 SwitchToSection(getObjFileLowering().SectionForGlobal(GVar, TM));
489 if (C->isNullValue() && !GVar->hasSection()) {
490 if (!GVar->isThreadLocal() &&
491 (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
492 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
494 if (GVar->hasLocalLinkage())
495 O << "\t.local\t" << name << '\n';
497 O << TAI->getCOMMDirective() << name << ',' << Size;
498 if (TAI->getCOMMDirectiveTakesAlignment())
499 O << ',' << (1 << Align);
505 switch (GVar->getLinkage()) {
506 case GlobalValue::LinkOnceAnyLinkage:
507 case GlobalValue::LinkOnceODRLinkage:
508 case GlobalValue::CommonLinkage:
509 case GlobalValue::WeakAnyLinkage:
510 case GlobalValue::WeakODRLinkage:
511 // FIXME: Verify correct for weak.
512 // Nonnull linkonce -> weak
513 O << "\t.weak " << name << '\n';
515 case GlobalValue::AppendingLinkage:
516 // FIXME: appending linkage variables should go into a section of their name
517 // or something. For now, just emit them as external.
518 case GlobalValue::ExternalLinkage:
519 // If external or appending, declare as a global symbol
520 O << TAI->getGlobalDirective() << name << '\n';
522 case GlobalValue::PrivateLinkage:
523 case GlobalValue::LinkerPrivateLinkage:
524 case GlobalValue::InternalLinkage:
525 if (CVA && CVA->isCString())
526 printSizeAndType = false;
528 case GlobalValue::GhostLinkage:
529 llvm_unreachable("Should not have any unmaterialized functions!");
530 case GlobalValue::DLLImportLinkage:
531 llvm_unreachable("DLLImport linkage is not supported by this target!");
532 case GlobalValue::DLLExportLinkage:
533 llvm_unreachable("DLLExport linkage is not supported by this target!");
535 llvm_unreachable("Unknown linkage type!");
538 EmitAlignment(Align, GVar);
540 if (TAI->hasDotTypeDotSizeDirective() && printSizeAndType) {
541 O << "\t.type " << name << ",@object\n";
542 O << "\t.size " << name << ',' << Size << '\n';
546 EmitGlobalConstant(C);
550 // Force static initialization.
551 extern "C" void LLVMInitializeMipsAsmPrinter() {
552 RegisterAsmPrinter<MipsAsmPrinter> X(TheMipsTarget);
553 RegisterAsmPrinter<MipsAsmPrinter> Y(TheMipselTarget);