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/DwarfWriter.h"
27 #include "llvm/CodeGen/MachineFunctionPass.h"
28 #include "llvm/CodeGen/MachineConstantPool.h"
29 #include "llvm/CodeGen/MachineFrameInfo.h"
30 #include "llvm/CodeGen/MachineInstr.h"
31 #include "llvm/MC/MCStreamer.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/MC/MCSymbol.h"
34 #include "llvm/Target/TargetData.h"
35 #include "llvm/Target/TargetLoweringObjectFile.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/Target/TargetRegistry.h"
39 #include "llvm/Support/ErrorHandling.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"
49 STATISTIC(EmittedInsts, "Number of machine instrs printed");
52 class MipsAsmPrinter : public AsmPrinter {
53 const MipsSubtarget *Subtarget;
55 explicit MipsAsmPrinter(formatted_raw_ostream &O, TargetMachine &TM,
56 const MCAsmInfo *T, bool V)
57 : AsmPrinter(O, TM, T, V) {
58 Subtarget = &TM.getSubtarget<MipsSubtarget>();
61 virtual const char *getPassName() const {
62 return "Mips Assembly Printer";
65 bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
66 unsigned AsmVariant, const char *ExtraCode);
67 void printOperand(const MachineInstr *MI, int opNum);
68 void printUnsignedImm(const MachineInstr *MI, int opNum);
69 void printMemOperand(const MachineInstr *MI, int opNum,
70 const char *Modifier = 0);
71 void printFCCOperand(const MachineInstr *MI, int opNum,
72 const char *Modifier = 0);
73 void printSavedRegsBitmask(MachineFunction &MF);
74 void printHex32(unsigned int Value);
76 const char *emitCurrentABIString();
77 void emitFunctionStart(MachineFunction &MF);
78 void emitFunctionEnd(MachineFunction &MF);
79 void emitFrameDirective(MachineFunction &MF);
81 void printInstruction(const MachineInstr *MI); // autogenerated.
82 static const char *getRegisterName(unsigned RegNo);
84 bool runOnMachineFunction(MachineFunction &F);
85 void EmitStartOfAsmFile(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::emitFrameDirective(MachineFunction &MF) {
182 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
184 unsigned stackReg = RI.getFrameRegister(MF);
185 unsigned returnReg = RI.getRARegister();
186 unsigned stackSize = MF.getFrameInfo()->getStackSize();
189 O << "\t.frame\t" << '$' << LowercaseString(getRegisterName(stackReg))
190 << ',' << stackSize << ','
191 << '$' << LowercaseString(getRegisterName(returnReg))
195 /// Emit Set directives.
196 const char *MipsAsmPrinter::emitCurrentABIString() {
197 switch(Subtarget->getTargetABI()) {
198 case MipsSubtarget::O32: return "abi32";
199 case MipsSubtarget::O64: return "abiO64";
200 case MipsSubtarget::N32: return "abiN32";
201 case MipsSubtarget::N64: return "abi64";
202 case MipsSubtarget::EABI: return "eabi32"; // TODO: handle eabi64
206 llvm_unreachable("Unknown Mips ABI");
210 /// Emit the directives used by GAS on the start of functions
211 void MipsAsmPrinter::emitFunctionStart(MachineFunction &MF) {
212 // Print out the label for the function.
213 const Function *F = MF.getFunction();
214 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
217 EmitAlignment(MF.getAlignment(), F);
219 O << "\t.globl\t" << *CurrentFnSym << '\n';
220 O << "\t.ent\t" << *CurrentFnSym << '\n';
222 printVisibility(CurrentFnSym, F->getVisibility());
224 if ((MAI->hasDotTypeDotSizeDirective()) && Subtarget->isLinux())
225 O << "\t.type\t" << *CurrentFnSym << ", @function\n";
227 O << *CurrentFnSym << ":\n";
229 emitFrameDirective(MF);
230 printSavedRegsBitmask(MF);
235 /// Emit the directives used by GAS on the end of functions
236 void MipsAsmPrinter::emitFunctionEnd(MachineFunction &MF) {
237 // There are instruction for this macros, but they must
238 // always be at the function end, and we can't emit and
239 // break with BB logic.
240 O << "\t.set\tmacro\n";
241 O << "\t.set\treorder\n";
243 O << "\t.end\t" << *CurrentFnSym << '\n';
244 if (MAI->hasDotTypeDotSizeDirective() && !Subtarget->isLinux())
245 O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
248 /// runOnMachineFunction - This uses the printMachineInstruction()
249 /// method to print assembly for each instruction.
250 bool MipsAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
253 SetupMachineFunction(MF);
255 // Print out constants referenced by the function
256 EmitConstantPool(MF.getConstantPool());
258 // Print out jump tables referenced by the function
259 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
263 // Emit the function start directives
264 emitFunctionStart(MF);
266 // Print out code for the function.
267 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
270 // Print a label for the basic block.
271 if (I != MF.begin()) {
272 EmitBasicBlockStart(I);
275 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
277 processDebugLoc(II, true);
279 // Print the assembly for the instruction.
280 printInstruction(II);
286 processDebugLoc(II, false);
290 // Each Basic Block is separated by a newline
294 // Emit function end directives
297 // We didn't modify anything.
301 // Print out an operand for an inline asm expression.
302 bool MipsAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
303 unsigned AsmVariant,const char *ExtraCode){
304 // Does this asm operand have a single letter operand modifier?
305 if (ExtraCode && ExtraCode[0])
306 return true; // Unknown modifier.
308 printOperand(MI, OpNo);
312 void MipsAsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
313 const MachineOperand &MO = MI->getOperand(opNum);
316 if (MO.getTargetFlags())
319 switch(MO.getTargetFlags()) {
320 case MipsII::MO_GPREL: O << "%gp_rel("; break;
321 case MipsII::MO_GOT_CALL: O << "%call16("; break;
323 if (MI->getOpcode() == Mips::LW)
328 case MipsII::MO_ABS_HILO:
329 if (MI->getOpcode() == Mips::LUi)
336 switch (MO.getType()) {
337 case MachineOperand::MO_Register:
338 O << '$' << LowercaseString(getRegisterName(MO.getReg()));
341 case MachineOperand::MO_Immediate:
342 O << (short int)MO.getImm();
345 case MachineOperand::MO_MachineBasicBlock:
346 O << *GetMBBSymbol(MO.getMBB()->getNumber());
349 case MachineOperand::MO_GlobalAddress:
350 O << *GetGlobalValueSymbol(MO.getGlobal());
353 case MachineOperand::MO_ExternalSymbol:
354 O << *GetExternalSymbolSymbol(MO.getSymbolName());
357 case MachineOperand::MO_JumpTableIndex:
358 O << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
359 << '_' << MO.getIndex();
362 case MachineOperand::MO_ConstantPoolIndex:
363 O << MAI->getPrivateGlobalPrefix() << "CPI"
364 << getFunctionNumber() << "_" << MO.getIndex();
366 O << "+" << MO.getOffset();
370 llvm_unreachable("<unknown operand type>");
373 if (closeP) O << ")";
376 void MipsAsmPrinter::printUnsignedImm(const MachineInstr *MI, int opNum) {
377 const MachineOperand &MO = MI->getOperand(opNum);
378 if (MO.getType() == MachineOperand::MO_Immediate)
379 O << (unsigned short int)MO.getImm();
381 printOperand(MI, opNum);
384 void MipsAsmPrinter::
385 printMemOperand(const MachineInstr *MI, int opNum, const char *Modifier) {
386 // when using stack locations for not load/store instructions
387 // print the same way as all normal 3 operand instructions.
388 if (Modifier && !strcmp(Modifier, "stackloc")) {
389 printOperand(MI, opNum+1);
391 printOperand(MI, opNum);
395 // Load/Store memory operands -- imm($reg)
396 // If PIC target the target is loaded as the
397 // pattern lw $25,%call16($28)
398 printOperand(MI, opNum);
400 printOperand(MI, opNum+1);
404 void MipsAsmPrinter::
405 printFCCOperand(const MachineInstr *MI, int opNum, const char *Modifier) {
406 const MachineOperand& MO = MI->getOperand(opNum);
407 O << Mips::MipsFCCToString((Mips::CondCode)MO.getImm());
410 void MipsAsmPrinter::EmitStartOfAsmFile(Module &M) {
411 // FIXME: Use SwitchSection.
413 // Tell the assembler which ABI we are using
414 O << "\t.section .mdebug." << emitCurrentABIString() << '\n';
416 // TODO: handle O64 ABI
417 if (Subtarget->isABI_EABI())
418 O << "\t.section .gcc_compiled_long" <<
419 (Subtarget->isGP32bit() ? "32" : "64") << '\n';
421 // return to previous section
422 O << "\t.previous" << '\n';
425 // Force static initialization.
426 extern "C" void LLVMInitializeMipsAsmPrinter() {
427 RegisterAsmPrinter<MipsAsmPrinter> X(TheMipsTarget);
428 RegisterAsmPrinter<MipsAsmPrinter> Y(TheMipselTarget);