1 //===-- X86MCInstLower.cpp - Convert X86 MachineInstr to an MCInst --------===//
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 code to lower X86 MachineInstrs to their corresponding
13 //===----------------------------------------------------------------------===//
15 #include "X86MCInstLower.h"
16 #include "X86AsmPrinter.h"
17 #include "X86COFFMachineModuleInfo.h"
18 #include "X86MCAsmInfo.h"
19 #include "X86MCTargetExpr.h"
20 #include "llvm/Analysis/DebugInfo.h"
21 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/MC/MCStreamer.h"
26 #include "llvm/MC/MCSymbol.h"
27 #include "llvm/Target/Mangler.h"
28 #include "llvm/Support/FormattedStream.h"
29 #include "llvm/ADT/SmallString.h"
30 #include "llvm/Type.h"
34 const X86Subtarget &X86MCInstLower::getSubtarget() const {
35 return AsmPrinter.getSubtarget();
38 MachineModuleInfoMachO &X86MCInstLower::getMachOMMI() const {
39 assert(getSubtarget().isTargetDarwin() &&"Can only get MachO info on darwin");
40 return AsmPrinter.MMI->getObjFileInfo<MachineModuleInfoMachO>();
44 MCSymbol *X86MCInstLower::GetPICBaseSymbol() const {
45 const TargetLowering *TLI = AsmPrinter.TM.getTargetLowering();
46 return static_cast<const X86TargetLowering*>(TLI)->
47 getPICBaseSymbol(AsmPrinter.MF, Ctx);
50 /// GetSymbolFromOperand - Lower an MO_GlobalAddress or MO_ExternalSymbol
51 /// operand to an MCSymbol.
52 MCSymbol *X86MCInstLower::
53 GetSymbolFromOperand(const MachineOperand &MO) const {
54 assert((MO.isGlobal() || MO.isSymbol()) && "Isn't a symbol reference");
56 SmallString<128> Name;
59 assert(MO.isSymbol());
60 Name += AsmPrinter.MAI->getGlobalPrefix();
61 Name += MO.getSymbolName();
62 } else if (getSubtarget().isTargetCygMing() &&
63 isa<Function>(MO.getGlobal())) {
64 const GlobalValue *GV = MO.getGlobal();
65 MCSymbol *Sym = Mang->getSymbol(GV);
66 Sym = X86COFFMachineModuleInfo::
67 DecorateCygMingName(Sym, Ctx, cast<Function>(GV),
68 *AsmPrinter.TM.getTargetData());
69 Name.append(Sym->getName().begin(), Sym->getName().end());
71 const GlobalValue *GV = MO.getGlobal();
72 bool isImplicitlyPrivate = false;
73 if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB ||
74 MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
75 MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE ||
76 MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
77 isImplicitlyPrivate = true;
79 Mang->getNameWithPrefix(Name, GV, isImplicitlyPrivate);
82 // If the target flags on the operand changes the name of the symbol, do that
83 // before we return the symbol.
84 switch (MO.getTargetFlags()) {
86 case X86II::MO_DLLIMPORT: {
87 // Handle dllimport linkage.
88 const char *Prefix = "__imp_";
89 Name.insert(Name.begin(), Prefix, Prefix+strlen(Prefix));
92 case X86II::MO_DARWIN_NONLAZY:
93 case X86II::MO_DARWIN_NONLAZY_PIC_BASE: {
94 Name += "$non_lazy_ptr";
95 MCSymbol *Sym = Ctx.GetOrCreateTemporarySymbol(Name.str());
97 MachineModuleInfoImpl::StubValueTy &StubSym =
98 getMachOMMI().getGVStubEntry(Sym);
99 if (StubSym.getPointer() == 0) {
100 assert(MO.isGlobal() && "Extern symbol not handled yet");
102 MachineModuleInfoImpl::
103 StubValueTy(AsmPrinter.GetGlobalValueSymbol(MO.getGlobal()),
104 !MO.getGlobal()->hasInternalLinkage());
108 case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: {
109 Name += "$non_lazy_ptr";
110 MCSymbol *Sym = Ctx.GetOrCreateTemporarySymbol(Name.str());
111 MachineModuleInfoImpl::StubValueTy &StubSym =
112 getMachOMMI().getHiddenGVStubEntry(Sym);
113 if (StubSym.getPointer() == 0) {
114 assert(MO.isGlobal() && "Extern symbol not handled yet");
116 MachineModuleInfoImpl::
117 StubValueTy(AsmPrinter.GetGlobalValueSymbol(MO.getGlobal()),
118 !MO.getGlobal()->hasInternalLinkage());
122 case X86II::MO_DARWIN_STUB: {
124 MCSymbol *Sym = Ctx.GetOrCreateTemporarySymbol(Name.str());
125 MachineModuleInfoImpl::StubValueTy &StubSym =
126 getMachOMMI().getFnStubEntry(Sym);
127 if (StubSym.getPointer())
132 MachineModuleInfoImpl::
133 StubValueTy(AsmPrinter.GetGlobalValueSymbol(MO.getGlobal()),
134 !MO.getGlobal()->hasInternalLinkage());
136 Name.erase(Name.end()-5, Name.end());
138 MachineModuleInfoImpl::
139 StubValueTy(Ctx.GetOrCreateTemporarySymbol(Name.str()), false);
145 return Ctx.GetOrCreateSymbol(Name.str());
148 MCOperand X86MCInstLower::LowerSymbolOperand(const MachineOperand &MO,
149 MCSymbol *Sym) const {
150 // FIXME: We would like an efficient form for this, so we don't have to do a
151 // lot of extra uniquing.
152 const MCExpr *Expr = 0;
153 X86MCTargetExpr::VariantKind RefKind = X86MCTargetExpr::Invalid;
155 switch (MO.getTargetFlags()) {
156 default: llvm_unreachable("Unknown target flag on GV operand");
157 case X86II::MO_NO_FLAG: // No flag.
158 // These affect the name of the symbol, not any suffix.
159 case X86II::MO_DARWIN_NONLAZY:
160 case X86II::MO_DLLIMPORT:
161 case X86II::MO_DARWIN_STUB:
164 case X86II::MO_TLSGD: RefKind = X86MCTargetExpr::TLSGD; break;
165 case X86II::MO_GOTTPOFF: RefKind = X86MCTargetExpr::GOTTPOFF; break;
166 case X86II::MO_INDNTPOFF: RefKind = X86MCTargetExpr::INDNTPOFF; break;
167 case X86II::MO_TPOFF: RefKind = X86MCTargetExpr::TPOFF; break;
168 case X86II::MO_NTPOFF: RefKind = X86MCTargetExpr::NTPOFF; break;
169 case X86II::MO_GOTPCREL: RefKind = X86MCTargetExpr::GOTPCREL; break;
170 case X86II::MO_GOT: RefKind = X86MCTargetExpr::GOT; break;
171 case X86II::MO_GOTOFF: RefKind = X86MCTargetExpr::GOTOFF; break;
172 case X86II::MO_PLT: RefKind = X86MCTargetExpr::PLT; break;
173 case X86II::MO_PIC_BASE_OFFSET:
174 case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
175 case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE:
176 Expr = MCSymbolRefExpr::Create(Sym, Ctx);
177 // Subtract the pic base.
178 Expr = MCBinaryExpr::CreateSub(Expr,
179 MCSymbolRefExpr::Create(GetPICBaseSymbol(), Ctx),
185 if (RefKind == X86MCTargetExpr::Invalid)
186 Expr = MCSymbolRefExpr::Create(Sym, Ctx);
188 Expr = X86MCTargetExpr::Create(Sym, RefKind, Ctx);
191 if (!MO.isJTI() && MO.getOffset())
192 Expr = MCBinaryExpr::CreateAdd(Expr,
193 MCConstantExpr::Create(MO.getOffset(), Ctx),
195 return MCOperand::CreateExpr(Expr);
200 static void lower_subreg32(MCInst *MI, unsigned OpNo) {
201 // Convert registers in the addr mode according to subreg32.
202 unsigned Reg = MI->getOperand(OpNo).getReg();
204 MI->getOperand(OpNo).setReg(getX86SubSuperRegister(Reg, MVT::i32));
207 static void lower_lea64_32mem(MCInst *MI, unsigned OpNo) {
208 // Convert registers in the addr mode according to subreg64.
209 for (unsigned i = 0; i != 4; ++i) {
210 if (!MI->getOperand(OpNo+i).isReg()) continue;
212 unsigned Reg = MI->getOperand(OpNo+i).getReg();
213 if (Reg == 0) continue;
215 MI->getOperand(OpNo+i).setReg(getX86SubSuperRegister(Reg, MVT::i64));
219 /// LowerSubReg32_Op0 - Things like MOVZX16rr8 -> MOVZX32rr8.
220 static void LowerSubReg32_Op0(MCInst &OutMI, unsigned NewOpc) {
221 OutMI.setOpcode(NewOpc);
222 lower_subreg32(&OutMI, 0);
224 /// LowerUnaryToTwoAddr - R = setb -> R = sbb R, R
225 static void LowerUnaryToTwoAddr(MCInst &OutMI, unsigned NewOpc) {
226 OutMI.setOpcode(NewOpc);
227 OutMI.addOperand(OutMI.getOperand(0));
228 OutMI.addOperand(OutMI.getOperand(0));
232 void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
233 OutMI.setOpcode(MI->getOpcode());
235 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
236 const MachineOperand &MO = MI->getOperand(i);
239 switch (MO.getType()) {
242 llvm_unreachable("unknown operand type");
243 case MachineOperand::MO_Register:
244 // Ignore all implicit register operands.
245 if (MO.isImplicit()) continue;
246 MCOp = MCOperand::CreateReg(MO.getReg());
248 case MachineOperand::MO_Immediate:
249 MCOp = MCOperand::CreateImm(MO.getImm());
251 case MachineOperand::MO_MachineBasicBlock:
252 MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
253 MO.getMBB()->getSymbol(Ctx), Ctx));
255 case MachineOperand::MO_GlobalAddress:
256 MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
258 case MachineOperand::MO_ExternalSymbol:
259 MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
261 case MachineOperand::MO_JumpTableIndex:
262 MCOp = LowerSymbolOperand(MO, AsmPrinter.GetJTISymbol(MO.getIndex()));
264 case MachineOperand::MO_ConstantPoolIndex:
265 MCOp = LowerSymbolOperand(MO, AsmPrinter.GetCPISymbol(MO.getIndex()));
267 case MachineOperand::MO_BlockAddress:
268 MCOp = LowerSymbolOperand(MO,
269 AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress()));
273 OutMI.addOperand(MCOp);
276 // Handle a few special cases to eliminate operand modifiers.
277 switch (OutMI.getOpcode()) {
278 case X86::LEA64_32r: // Handle 'subreg rewriting' for the lea64_32mem operand.
279 lower_lea64_32mem(&OutMI, 1);
281 case X86::MOVZX16rr8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr8); break;
282 case X86::MOVZX16rm8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm8); break;
283 case X86::MOVSX16rr8: LowerSubReg32_Op0(OutMI, X86::MOVSX32rr8); break;
284 case X86::MOVSX16rm8: LowerSubReg32_Op0(OutMI, X86::MOVSX32rm8); break;
285 case X86::MOVZX64rr32: LowerSubReg32_Op0(OutMI, X86::MOV32rr); break;
286 case X86::MOVZX64rm32: LowerSubReg32_Op0(OutMI, X86::MOV32rm); break;
287 case X86::MOV64ri64i32: LowerSubReg32_Op0(OutMI, X86::MOV32ri); break;
288 case X86::MOVZX64rr8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr8); break;
289 case X86::MOVZX64rm8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm8); break;
290 case X86::MOVZX64rr16: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr16); break;
291 case X86::MOVZX64rm16: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm16); break;
292 case X86::SETB_C8r: LowerUnaryToTwoAddr(OutMI, X86::SBB8rr); break;
293 case X86::SETB_C16r: LowerUnaryToTwoAddr(OutMI, X86::SBB16rr); break;
294 case X86::SETB_C32r: LowerUnaryToTwoAddr(OutMI, X86::SBB32rr); break;
295 case X86::SETB_C64r: LowerUnaryToTwoAddr(OutMI, X86::SBB64rr); break;
296 case X86::MOV8r0: LowerUnaryToTwoAddr(OutMI, X86::XOR8rr); break;
297 case X86::MOV32r0: LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); break;
298 case X86::MMX_V_SET0: LowerUnaryToTwoAddr(OutMI, X86::MMX_PXORrr); break;
299 case X86::MMX_V_SETALLONES:
300 LowerUnaryToTwoAddr(OutMI, X86::MMX_PCMPEQDrr); break;
301 case X86::FsFLD0SS: LowerUnaryToTwoAddr(OutMI, X86::PXORrr); break;
302 case X86::FsFLD0SD: LowerUnaryToTwoAddr(OutMI, X86::PXORrr); break;
303 case X86::V_SET0: LowerUnaryToTwoAddr(OutMI, X86::XORPSrr); break;
304 case X86::V_SETALLONES: LowerUnaryToTwoAddr(OutMI, X86::PCMPEQDrr); break;
307 LowerSubReg32_Op0(OutMI, X86::MOV32r0); // MOV16r0 -> MOV32r0
308 LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); // MOV32r0 -> XOR32rr
311 LowerSubReg32_Op0(OutMI, X86::MOV32r0); // MOV64r0 -> MOV32r0
312 LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); // MOV32r0 -> XOR32rr
319 void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
320 X86MCInstLower MCInstLowering(OutContext, Mang, *this);
321 switch (MI->getOpcode()) {
322 case TargetOpcode::DBG_VALUE: {
323 // FIXME: if this is implemented for another target before it goes
324 // away completely, the common part should be moved into AsmPrinter.
327 O << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
328 unsigned NOps = MI->getNumOperands();
329 // cast away const; DIetc do not take const operands for some reason.
330 DIVariable V((MDNode*)(MI->getOperand(NOps-1).getMetadata()));
334 // Register or immediate value. Register 0 means undef.
335 assert(MI->getOperand(0).getType()==MachineOperand::MO_Register ||
336 MI->getOperand(0).getType()==MachineOperand::MO_Immediate ||
337 MI->getOperand(0).getType()==MachineOperand::MO_FPImmediate);
338 if (MI->getOperand(0).getType()==MachineOperand::MO_Register &&
339 MI->getOperand(0).getReg()==0) {
340 // Suppress offset in this case, it is not meaningful.
342 OutStreamer.AddBlankLine();
344 } else if (MI->getOperand(0).getType()==MachineOperand::MO_FPImmediate) {
345 // This is more naturally done in printOperand, but since the only use
346 // of such an operand is in this comment and that is temporary (and it's
347 // ugly), we prefer to keep this localized.
348 // The include of Type.h may be removable when this code is.
349 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy() ||
350 MI->getOperand(0).getFPImm()->getType()->isDoubleTy())
351 MI->getOperand(0).print(O, &TM);
353 // There is no good way to print long double. Convert a copy to
354 // double. Ah well, it's only a comment.
356 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
357 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
359 O << "(long double) " << APF.convertToDouble();
364 if (MI->getOperand(0).getType()==MachineOperand::MO_Register &&
365 MI->getOperand(0).getReg()==0) {
366 // Suppress offset in this case, it is not meaningful.
368 OutStreamer.AddBlankLine();
371 // Frame address. Currently handles register +- offset only.
372 assert(MI->getOperand(0).getType()==MachineOperand::MO_Register);
373 assert(MI->getOperand(3).getType()==MachineOperand::MO_Immediate);
374 O << '['; printOperand(MI, 0); O << '+'; printOperand(MI, 3); O << ']';
377 printOperand(MI, NOps-2);
378 OutStreamer.AddBlankLine();
381 case X86::MOVPC32r: {
383 // This is a pseudo op for a two instruction sequence with a label, which
390 MCSymbol *PICBase = MCInstLowering.GetPICBaseSymbol();
391 TmpInst.setOpcode(X86::CALLpcrel32);
392 // FIXME: We would like an efficient form for this, so we don't have to do a
393 // lot of extra uniquing.
394 TmpInst.addOperand(MCOperand::CreateExpr(MCSymbolRefExpr::Create(PICBase,
396 OutStreamer.EmitInstruction(TmpInst);
399 OutStreamer.EmitLabel(PICBase);
402 TmpInst.setOpcode(X86::POP32r);
403 TmpInst.getOperand(0) = MCOperand::CreateReg(MI->getOperand(0).getReg());
404 OutStreamer.EmitInstruction(TmpInst);
409 // Lower the MO_GOT_ABSOLUTE_ADDRESS form of ADD32ri.
410 if (MI->getOperand(2).getTargetFlags() != X86II::MO_GOT_ABSOLUTE_ADDRESS)
413 // Okay, we have something like:
414 // EAX = ADD32ri EAX, MO_GOT_ABSOLUTE_ADDRESS(@MYGLOBAL)
416 // For this, we want to print something like:
417 // MYGLOBAL + (. - PICBASE)
418 // However, we can't generate a ".", so just emit a new label here and refer
420 MCSymbol *DotSym = OutContext.GetOrCreateTemporarySymbol();
421 OutStreamer.EmitLabel(DotSym);
423 // Now that we have emitted the label, lower the complex operand expression.
424 MCSymbol *OpSym = MCInstLowering.GetSymbolFromOperand(MI->getOperand(2));
426 const MCExpr *DotExpr = MCSymbolRefExpr::Create(DotSym, OutContext);
427 const MCExpr *PICBase =
428 MCSymbolRefExpr::Create(MCInstLowering.GetPICBaseSymbol(), OutContext);
429 DotExpr = MCBinaryExpr::CreateSub(DotExpr, PICBase, OutContext);
431 DotExpr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(OpSym,OutContext),
432 DotExpr, OutContext);
435 TmpInst.setOpcode(X86::ADD32ri);
436 TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
437 TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
438 TmpInst.addOperand(MCOperand::CreateExpr(DotExpr));
439 OutStreamer.EmitInstruction(TmpInst);
445 MCInstLowering.Lower(MI, TmpInst);
447 OutStreamer.EmitInstruction(TmpInst);