1 //===-- X86/Printer.cpp - Convert X86 code to human readable rep. ---------===//
3 // This file contains a printer that converts from our internal representation
4 // of LLVM code to a nice human readable form that is suitable for debuggging.
6 //===----------------------------------------------------------------------===//
9 #include "X86InstrInfo.h"
10 #include "llvm/Pass.h"
11 #include "llvm/Function.h"
12 #include "llvm/Target/TargetMachine.h"
13 #include "llvm/CodeGen/MachineFunction.h"
14 #include "llvm/CodeGen/MachineInstr.h"
15 #include "Support/Statistic.h"
18 struct Printer : public FunctionPass {
22 Printer(TargetMachine &tm, std::ostream &o) : TM(tm), O(o) {}
24 bool runOnFunction(Function &F);
28 /// createX86CodePrinterPass - Print out the specified machine code function to
29 /// the specified stream. This function should work regardless of whether or
30 /// not the function is in SSA form or not.
32 Pass *createX86CodePrinterPass(TargetMachine &TM, std::ostream &O) {
33 return new Printer(TM, O);
37 /// runOnFunction - This uses the X86InstructionInfo::print method
38 /// to print assembly for each instruction.
39 bool Printer::runOnFunction (Function & F)
41 static unsigned bbnumber = 0;
42 MachineFunction & MF = MachineFunction::get (&F);
43 const MachineInstrInfo & MII = TM.getInstrInfo ();
45 // Print out labels for the function.
46 O << "\t.globl\t" << F.getName () << "\n";
47 O << "\t.type\t" << F.getName () << ", @function\n";
48 O << F.getName () << ":\n";
50 // Print out code for the function.
51 for (MachineFunction::const_iterator bb_i = MF.begin (), bb_e = MF.end ();
54 // Print a label for the basic block.
55 O << ".BB" << bbnumber++ << ":\n";
56 for (MachineBasicBlock::const_iterator i_i = bb_i->begin (), i_e =
57 bb_i->end (); i_i != i_e; ++i_i)
59 // Print the assembly for the instruction.
61 MII.print(*i_i, O, TM);
65 // We didn't modify anything.
69 static bool isReg(const MachineOperand &MO) {
70 return MO.getType() == MachineOperand::MO_VirtualRegister ||
71 MO.getType() == MachineOperand::MO_MachineRegister;
74 static bool isImmediate(const MachineOperand &MO) {
75 return MO.getType() == MachineOperand::MO_SignExtendedImmed ||
76 MO.getType() == MachineOperand::MO_UnextendedImmed;
79 static bool isPCRelativeDisp(const MachineOperand &MO) {
80 return MO.getType() == MachineOperand::MO_PCRelativeDisp;
83 static bool isScale(const MachineOperand &MO) {
84 return isImmediate(MO) &&
85 (MO.getImmedValue() == 1 || MO.getImmedValue() == 2 ||
86 MO.getImmedValue() == 4 || MO.getImmedValue() == 8);
89 static bool isMem(const MachineInstr *MI, unsigned Op) {
90 return Op+4 <= MI->getNumOperands() &&
91 isReg(MI->getOperand(Op )) && isScale(MI->getOperand(Op+1)) &&
92 isReg(MI->getOperand(Op+2)) && isImmediate(MI->getOperand(Op+3));
95 static void printOp(std::ostream &O, const MachineOperand &MO,
96 const MRegisterInfo &RI) {
97 switch (MO.getType()) {
98 case MachineOperand::MO_VirtualRegister:
99 case MachineOperand::MO_MachineRegister:
100 if (MO.getReg() < MRegisterInfo::FirstVirtualRegister)
101 O << RI.get(MO.getReg()).Name;
103 O << "%reg" << MO.getReg();
106 case MachineOperand::MO_SignExtendedImmed:
107 case MachineOperand::MO_UnextendedImmed:
108 O << (int)MO.getImmedValue();
110 case MachineOperand::MO_PCRelativeDisp:
111 O << "<" << MO.getVRegValue()->getName() << ">";
114 O << "<unknown op ty>"; return;
118 static void printMemReference(std::ostream &O, const MachineInstr *MI,
119 unsigned Op, const MRegisterInfo &RI) {
120 assert(isMem(MI, Op) && "Invalid memory reference!");
121 const MachineOperand &BaseReg = MI->getOperand(Op);
122 const MachineOperand &Scale = MI->getOperand(Op+1);
123 const MachineOperand &IndexReg = MI->getOperand(Op+2);
124 const MachineOperand &Disp = MI->getOperand(Op+3);
127 bool NeedPlus = false;
128 if (BaseReg.getReg()) {
129 printOp(O, BaseReg, RI);
133 if (IndexReg.getReg()) {
134 if (NeedPlus) O << " + ";
135 if (IndexReg.getImmedValue() != 1)
136 O << IndexReg.getImmedValue() << "*";
137 printOp(O, IndexReg, RI);
141 if (Disp.getImmedValue()) {
142 if (NeedPlus) O << " + ";
143 printOp(O, Disp, RI);
148 // print - Print out an x86 instruction in intel syntax
149 void X86InstrInfo::print(const MachineInstr *MI, std::ostream &O,
150 const TargetMachine &TM) const {
151 unsigned Opcode = MI->getOpcode();
152 const MachineInstrDescriptor &Desc = get(Opcode);
154 switch (Desc.TSFlags & X86II::FormMask) {
156 // The accepted forms of Raw instructions are:
157 // 1. nop - No operand required
158 // 2. jmp foo - PC relative displacement operand
160 assert(MI->getNumOperands() == 0 ||
161 (MI->getNumOperands() == 1 && isPCRelativeDisp(MI->getOperand(0))) &&
162 "Illegal raw instruction!");
163 O << getName(MI->getOpCode()) << " ";
165 if (MI->getNumOperands() == 1) {
166 printOp(O, MI->getOperand(0), RI);
171 case X86II::AddRegFrm: {
172 // There are currently two forms of acceptable AddRegFrm instructions.
173 // Either the instruction JUST takes a single register (like inc, dec, etc),
174 // or it takes a register and an immediate of the same size as the register
175 // (move immediate f.e.).
177 assert(isReg(MI->getOperand(0)) &&
178 (MI->getNumOperands() == 1 ||
179 (MI->getNumOperands() == 2 && isImmediate(MI->getOperand(1)))) &&
180 "Illegal form for AddRegFrm instruction!");
182 unsigned Reg = MI->getOperand(0).getReg();
184 O << getName(MI->getOpCode()) << " ";
185 printOp(O, MI->getOperand(0), RI);
186 if (MI->getNumOperands() == 2) {
188 printOp(O, MI->getOperand(1), RI);
193 case X86II::MRMDestReg: {
194 // There are two acceptable forms of MRMDestReg instructions, those with 3
197 // 3 Operands: in this form, the first two registers (the destination, and
198 // the first operand) should be the same, post register allocation. The 3rd
199 // operand is an additional input. This should be for things like add
202 // 2 Operands: this is for things like mov that do not read a second input
204 assert(isReg(MI->getOperand(0)) &&
205 (MI->getNumOperands() == 2 ||
206 (MI->getNumOperands() == 3 && isReg(MI->getOperand(1)))) &&
207 isReg(MI->getOperand(MI->getNumOperands()-1))
208 && "Bad format for MRMDestReg!");
209 if (MI->getNumOperands() == 3 &&
210 MI->getOperand(0).getReg() != MI->getOperand(1).getReg())
213 O << getName(MI->getOpCode()) << " ";
214 printOp(O, MI->getOperand(0), RI);
216 printOp(O, MI->getOperand(MI->getNumOperands()-1), RI);
221 case X86II::MRMDestMem: {
222 // These instructions are the same as MRMDestReg, but instead of having a
223 // register reference for the mod/rm field, it's a memory reference.
225 assert(isMem(MI, 0) && MI->getNumOperands() == 4+1 &&
226 isReg(MI->getOperand(4)) && "Bad format for MRMDestMem!");
228 O << getName(MI->getOpCode()) << " <SIZE> PTR ";
229 printMemReference(O, MI, 0, RI);
231 printOp(O, MI->getOperand(4), RI);
236 case X86II::MRMSrcReg: {
237 // There is a two forms that are acceptable for MRMSrcReg instructions,
238 // those with 3 and 2 operands:
240 // 3 Operands: in this form, the last register (the second input) is the
241 // ModR/M input. The first two operands should be the same, post register
242 // allocation. This is for things like: add r32, r/m32
244 // 2 Operands: this is for things like mov that do not read a second input
246 assert(isReg(MI->getOperand(0)) &&
247 isReg(MI->getOperand(1)) &&
248 (MI->getNumOperands() == 2 ||
249 (MI->getNumOperands() == 3 && isReg(MI->getOperand(2))))
250 && "Bad format for MRMDestReg!");
251 if (MI->getNumOperands() == 3 &&
252 MI->getOperand(0).getReg() != MI->getOperand(1).getReg())
255 O << getName(MI->getOpCode()) << " ";
256 printOp(O, MI->getOperand(0), RI);
258 printOp(O, MI->getOperand(MI->getNumOperands()-1), RI);
263 case X86II::MRMSrcMem: {
264 // These instructions are the same as MRMSrcReg, but instead of having a
265 // register reference for the mod/rm field, it's a memory reference.
267 assert(isReg(MI->getOperand(0)) &&
268 (MI->getNumOperands() == 1+4 && isMem(MI, 1)) ||
269 (MI->getNumOperands() == 2+4 && isReg(MI->getOperand(1)) &&
271 && "Bad format for MRMDestReg!");
272 if (MI->getNumOperands() == 2+4 &&
273 MI->getOperand(0).getReg() != MI->getOperand(1).getReg())
276 O << getName(MI->getOpCode()) << " ";
277 printOp(O, MI->getOperand(0), RI);
278 O << ", <SIZE> PTR ";
279 printMemReference(O, MI, MI->getNumOperands()-4, RI);
284 case X86II::MRMS0r: case X86II::MRMS1r:
285 case X86II::MRMS2r: case X86II::MRMS3r:
286 case X86II::MRMS4r: case X86II::MRMS5r:
287 case X86II::MRMS6r: case X86II::MRMS7r: {
288 // In this form, the following are valid formats:
290 // 2. cmp reg, immediate
291 // 2. shl rdest, rinput <implicit CL or 1>
292 // 3. sbb rdest, rinput, immediate [rdest = rinput]
294 assert(MI->getNumOperands() > 0 && MI->getNumOperands() < 4 &&
295 isReg(MI->getOperand(0)) && "Bad MRMSxR format!");
296 assert((MI->getNumOperands() != 2 ||
297 isReg(MI->getOperand(1)) || isImmediate(MI->getOperand(1))) &&
298 "Bad MRMSxR format!");
299 assert((MI->getNumOperands() < 3 ||
300 (isReg(MI->getOperand(1)) && isImmediate(MI->getOperand(2)))) &&
301 "Bad MRMSxR format!");
303 if (MI->getNumOperands() > 1 && isReg(MI->getOperand(1)) &&
304 MI->getOperand(0).getReg() != MI->getOperand(1).getReg())
307 O << getName(MI->getOpCode()) << " ";
308 printOp(O, MI->getOperand(0), RI);
309 if (isImmediate(MI->getOperand(MI->getNumOperands()-1))) {
311 printOp(O, MI->getOperand(MI->getNumOperands()-1), RI);
319 O << "\t\t\t-"; MI->print(O, TM); break;