1 //===-- MipsAsmPrinter.cpp - Mips LLVM assembly writer --------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Bruno Cardoso Lopes and is distributed under the
6 // University of Illinois Open Source 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 "MipsInstrInfo.h"
19 #include "MipsTargetMachine.h"
20 #include "MipsMachineFunction.h"
21 #include "llvm/Constants.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/Module.h"
24 #include "llvm/CodeGen/AsmPrinter.h"
25 #include "llvm/CodeGen/MachineFunctionPass.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineFrameInfo.h"
28 #include "llvm/CodeGen/MachineInstr.h"
29 #include "llvm/Target/TargetAsmInfo.h"
30 #include "llvm/Target/TargetData.h"
31 #include "llvm/Target/TargetMachine.h"
32 #include "llvm/Support/Mangler.h"
33 #include "llvm/ADT/Statistic.h"
34 #include "llvm/ADT/SetVector.h"
35 #include "llvm/ADT/StringExtras.h"
36 #include "llvm/Support/Debug.h"
37 #include "llvm/Support/CommandLine.h"
38 #include "llvm/Support/MathExtras.h"
43 STATISTIC(EmittedInsts, "Number of machine instrs printed");
46 struct VISIBILITY_HIDDEN MipsAsmPrinter : public AsmPrinter {
47 MipsAsmPrinter(std::ostream &O, MipsTargetMachine &TM,
48 const TargetAsmInfo *T):
49 AsmPrinter(O, TM, T) {}
51 virtual const char *getPassName() const {
52 return "Mips Assembly Printer";
55 enum SetDirectiveFlags {
56 REORDER, // enables instruction reordering.
57 NOREORDER, // disables instruction reordering.
58 MACRO, // enables GAS macros.
59 NOMACRO // disables GAS macros.
62 void printOperand(const MachineInstr *MI, int opNum);
63 void printMemOperand(const MachineInstr *MI, int opNum,
64 const char *Modifier = 0);
66 unsigned int getSavedRegsBitmask(bool isFloat, MachineFunction &MF);
67 void printHex32(unsigned int Value);
69 void emitFunctionStart(MachineFunction &MF);
70 void emitFunctionEnd(MachineFunction &MF);
71 void emitFrameDirective(MachineFunction &MF);
72 void emitMaskDirective(MachineFunction &MF);
73 void emitFMaskDirective(MachineFunction &MF);
74 void emitSetDirective(SetDirectiveFlags Flag);
76 bool printInstruction(const MachineInstr *MI); // autogenerated.
77 bool runOnMachineFunction(MachineFunction &F);
78 bool doInitialization(Module &M);
79 bool doFinalization(Module &M);
81 } // end of anonymous namespace
83 #include "MipsGenAsmWriter.inc"
85 /// createMipsCodePrinterPass - Returns a pass that prints the MIPS
86 /// assembly code for a MachineFunction to the given output stream,
87 /// using the given target machine description. This should work
88 /// regardless of whether the function is in SSA form.
89 FunctionPass *llvm::createMipsCodePrinterPass(std::ostream &o,
90 MipsTargetMachine &tm)
92 return new MipsAsmPrinter(o, tm, tm.getTargetAsmInfo());
95 //===----------------------------------------------------------------------===//
97 // Mips Asm Directives
99 // -- Frame directive "frame Stackpointer, Stacksize, RARegister"
100 // Describe the stack frame.
102 // -- Mask directives "(f)mask bitmask, offset"
103 // Tells the assembler which registers are saved and where.
104 // bitmask - contain a little endian bitset indicating which registers are
105 // saved on function prologue (e.g. with a 0x80000000 mask, the
106 // assembler knows the register 31 (RA) is saved at prologue.
107 // offset - the position before stack pointer subtraction indicating where
108 // the first saved register on prologue is located. (e.g. with a
110 // Consider the following function prologue:
113 // .mask 0xc0000000,-8
114 // addiu $sp, $sp, -48
118 // With a 0xc0000000 mask, the assembler knows the register 31 (RA) and
119 // 30 (FP) are saved at prologue. As the save order on prologue is from
120 // left to right, RA is saved first. A -8 offset means that after the
121 // stack pointer subtration, the first register in the mask (RA) will be
122 // saved at address 48-8=40.
124 //===----------------------------------------------------------------------===//
126 /// Mask directive for GPR
127 void MipsAsmPrinter::
128 emitMaskDirective(MachineFunction &MF)
130 MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
132 int StackSize = MF.getFrameInfo()->getStackSize();
133 int Offset = (!MipsFI->getTopSavedRegOffset()) ? 0 :
134 (-(StackSize-MipsFI->getTopSavedRegOffset()));
137 DOUT << "--> emitMaskDirective" << "\n";
138 DOUT << "StackSize : " << StackSize << "\n";
139 DOUT << "getTopSavedReg : " << MipsFI->getTopSavedRegOffset() << "\n";
140 DOUT << "Offset : " << Offset << "\n\n";
143 unsigned int Bitmask = getSavedRegsBitmask(false, MF);
146 O << "," << Offset << "\n";
149 /// TODO: Mask Directive for Float Point
150 void MipsAsmPrinter::
151 emitFMaskDirective(MachineFunction &MF)
153 unsigned int Bitmask = getSavedRegsBitmask(true, MF);
161 void MipsAsmPrinter::
162 emitFrameDirective(MachineFunction &MF)
164 const MRegisterInfo &RI = *TM.getRegisterInfo();
166 unsigned stackReg = RI.getFrameRegister(MF);
167 unsigned returnReg = RI.getRARegister();
168 unsigned stackSize = MF.getFrameInfo()->getStackSize();
171 O << "\t.frame\t" << "$" << LowercaseString(RI.get(stackReg).Name)
172 << "," << stackSize << ","
173 << "$" << LowercaseString(RI.get(returnReg).Name)
177 /// Emit Set directives.
178 void MipsAsmPrinter::
179 emitSetDirective(SetDirectiveFlags Flag)
183 case REORDER: O << "reorder" << "\n"; break;
184 case NOREORDER: O << "noreorder" << "\n"; break;
185 case MACRO: O << "macro" << "\n"; break;
186 case NOMACRO: O << "nomacro" << "\n"; break;
191 // Create a bitmask with all callee saved registers for CPU
192 // or Float Point registers. For CPU registers consider RA,
193 // GP and FP for saving if necessary.
194 unsigned int MipsAsmPrinter::
195 getSavedRegsBitmask(bool isFloat, MachineFunction &MF)
197 const MRegisterInfo &RI = *TM.getRegisterInfo();
199 // Float Point Registers, TODO
204 unsigned int Bitmask = 0;
206 MachineFrameInfo *MFI = MF.getFrameInfo();
207 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
208 for (unsigned i = 0, e = CSI.size(); i != e; ++i)
209 Bitmask |= (1 << MipsRegisterInfo::getRegisterNumbering(CSI[i].getReg()));
212 Bitmask |= (1 << MipsRegisterInfo::
213 getRegisterNumbering(RI.getFrameRegister(MF)));
215 if (MF.getFrameInfo()->hasCalls())
216 Bitmask |= (1 << MipsRegisterInfo::
217 getRegisterNumbering(RI.getRARegister()));
222 // Print a 32 bit hex number with all numbers.
223 void MipsAsmPrinter::
224 printHex32(unsigned int Value)
226 O << "0x" << std::hex;
227 for (int i = 7; i >= 0; i--)
228 O << std::hex << ( (Value & (0xF << (i*4))) >> (i*4) );
232 /// Emit the directives used by GAS on the start of functions
233 void MipsAsmPrinter::
234 emitFunctionStart(MachineFunction &MF)
236 // Print out the label for the function.
237 const Function *F = MF.getFunction();
238 SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
240 // On Mips GAS, if .align #n is present, #n means the number of bits
241 // to be cleared. So, if we want 4 byte alignment, we must have .align 2
244 O << "\t.globl\t" << CurrentFnName << "\n";
245 O << "\t.ent\t" << CurrentFnName << "\n";
246 O << "\t.type\t" << CurrentFnName << ", @function\n";
247 O << CurrentFnName << ":\n";
249 emitFrameDirective(MF);
250 emitMaskDirective(MF);
251 emitFMaskDirective(MF);
253 if (TM.getRelocationModel() == Reloc::Static) {
254 emitSetDirective(NOREORDER);
255 emitSetDirective(NOMACRO);
261 /// Emit the directives used by GAS on the end of functions
262 void MipsAsmPrinter::
263 emitFunctionEnd(MachineFunction &MF)
265 if (TM.getRelocationModel() == Reloc::Static) {
266 emitSetDirective(MACRO);
267 emitSetDirective(REORDER);
270 O << "\t.end\t" << CurrentFnName << "\n";
273 /// runOnMachineFunction - This uses the printMachineInstruction()
274 /// method to print assembly for each instruction.
275 bool MipsAsmPrinter::
276 runOnMachineFunction(MachineFunction &MF)
278 SetupMachineFunction(MF);
280 // Print out constants referenced by the function
281 EmitConstantPool(MF.getConstantPool());
285 // What's my mangled name?
286 CurrentFnName = Mang->getValueName(MF.getFunction());
288 // Emit the function start directives
289 emitFunctionStart(MF);
291 // Print out code for the function.
292 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
295 // Print a label for the basic block.
296 if (I != MF.begin()) {
297 printBasicBlockLabel(I, true);
301 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
303 // Print the assembly for the instruction.
305 printInstruction(II);
309 // Each Basic Block is separated by a newline
313 // Emit function end directives
316 // We didn't modify anything.
320 void MipsAsmPrinter::
321 printOperand(const MachineInstr *MI, int opNum)
323 const MachineOperand &MO = MI->getOperand(opNum);
324 const MRegisterInfo &RI = *TM.getRegisterInfo();
326 bool isPIC = (TM.getRelocationModel() == Reloc::PIC_);
327 bool isCodeLarge = (TM.getCodeModel() == CodeModel::Large);
329 // %hi and %lo used on mips gas to load global addresses on
330 // static code. %got is used to load global addresses when
331 // using PIC_. %call16 is used to load direct call targets
332 // on PIC_ and small code size. %call_lo and %call_hi load
333 // direct call targets on PIC_ and large code size.
334 if (MI->getOpcode() == Mips::LUi && !MO.isRegister()
335 && !MO.isImmediate()) {
336 if ((isPIC) && (isCodeLarge))
341 } else if ((MI->getOpcode() == Mips::ADDiu) && !MO.isRegister()
342 && !MO.isImmediate()) {
345 } else if ((isPIC) && (MI->getOpcode() == Mips::LW)
346 && (!MO.isRegister()) && (!MO.isImmediate())) {
347 const MachineOperand &firstMO = MI->getOperand(opNum-1);
348 const MachineOperand &lastMO = MI->getOperand(opNum+1);
349 if ((firstMO.isRegister()) && (lastMO.isRegister())) {
350 if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() == Mips::GP)
353 else if ((firstMO.getReg() != Mips::T9) && (lastMO.getReg() == Mips::GP))
355 else if ((firstMO.getReg() == Mips::T9) && (lastMO.getReg() != Mips::GP)
362 switch (MO.getType())
364 case MachineOperand::MO_Register:
365 if (MRegisterInfo::isPhysicalRegister(MO.getReg()))
366 O << "$" << LowercaseString (RI.get(MO.getReg()).Name);
368 O << "$" << MO.getReg();
371 case MachineOperand::MO_Immediate:
372 if ((MI->getOpcode() == Mips::SLTiu) || (MI->getOpcode() == Mips::ORi) ||
373 (MI->getOpcode() == Mips::LUi) || (MI->getOpcode() == Mips::ANDi))
374 O << (unsigned short int)MO.getImmedValue();
376 O << (short int)MO.getImmedValue();
379 case MachineOperand::MO_MachineBasicBlock:
380 printBasicBlockLabel(MO.getMachineBasicBlock());
383 case MachineOperand::MO_GlobalAddress:
384 O << Mang->getValueName(MO.getGlobal());
387 case MachineOperand::MO_ExternalSymbol:
388 O << MO.getSymbolName();
391 // FIXME: Verify correct
392 case MachineOperand::MO_ConstantPoolIndex:
393 O << TAI->getPrivateGlobalPrefix() << "CPI"
394 << getFunctionNumber() << "_" << MO.getConstantPoolIndex();
398 O << "<unknown operand type>"; abort (); break;
401 if (closeP) O << ")";
404 void MipsAsmPrinter::
405 printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier)
407 // when using stack locations for not load/store instructions
408 // print the same way as all normal 3 operand instructions.
409 if (Modifier && !strcmp(Modifier, "stackloc")) {
410 printOperand(MI, opNum+1);
412 printOperand(MI, opNum);
416 // Load/Store memory operands -- imm($reg)
417 // If PIC target the target is loaded as the
418 // pattern lw $25,%call16($28)
419 printOperand(MI, opNum);
421 printOperand(MI, opNum+1);
425 bool MipsAsmPrinter::
426 doInitialization(Module &M)
428 Mang = new Mangler(M);
429 return false; // success
432 bool MipsAsmPrinter::
433 doFinalization(Module &M)
435 const TargetData *TD = TM.getTargetData();
437 // Print out module-level global variables here.
438 for (Module::const_global_iterator I = M.global_begin(),
439 E = M.global_end(); I != E; ++I)
441 // External global require no code
442 if (I->hasInitializer()) {
444 // Check to see if this is a special global
445 // used by LLVM, if so, emit it.
446 if (EmitSpecialLLVMGlobal(I))
450 std::string name = Mang->getValueName(I);
451 Constant *C = I->getInitializer();
452 unsigned Size = TD->getABITypeSize(C->getType());
453 unsigned Align = TD->getPrefTypeAlignment(C->getType());
455 if (C->isNullValue() && (I->hasLinkOnceLinkage() ||
456 I->hasInternalLinkage() || I->hasWeakLinkage()
457 /* FIXME: Verify correct */)) {
459 SwitchToDataSection(".data", I);
460 if (I->hasInternalLinkage())
461 O << "\t.local " << name << "\n";
463 O << "\t.comm " << name << ","
464 << TD->getABITypeSize(C->getType())
465 << "," << Align << "\n";
469 switch (I->getLinkage())
471 case GlobalValue::LinkOnceLinkage:
472 case GlobalValue::WeakLinkage:
473 // FIXME: Verify correct for weak.
474 // Nonnull linkonce -> weak
475 O << "\t.weak " << name << "\n";
476 SwitchToDataSection("", I);
477 O << "\t.section\t\".llvm.linkonce.d." << name
478 << "\",\"aw\",@progbits\n";
480 case GlobalValue::AppendingLinkage:
481 // FIXME: appending linkage variables
482 // should go into a section of their name or
483 // something. For now, just emit them as external.
484 case GlobalValue::ExternalLinkage:
485 // If external or appending, declare as a global symbol
486 O << "\t.globl " << name << "\n";
487 case GlobalValue::InternalLinkage:
488 if (C->isNullValue())
489 SwitchToDataSection(".bss", I);
491 SwitchToDataSection(".data", I);
493 case GlobalValue::GhostLinkage:
494 cerr << "Should not have any"
495 << "unmaterialized functions!\n";
497 case GlobalValue::DLLImportLinkage:
498 cerr << "DLLImport linkage is"
499 << "not supported by this target!\n";
501 case GlobalValue::DLLExportLinkage:
502 cerr << "DLLExport linkage is"
503 << "not supported by this target!\n";
506 assert(0 && "Unknown linkage type!");
509 O << "\t.align " << Align << "\n";
510 O << "\t.type " << name << ",@object\n";
511 O << "\t.size " << name << "," << Size << "\n";
513 EmitGlobalConstant(C);
517 return AsmPrinter::doFinalization(M);