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 X86COFFMachineModuleInfo &COFFMMI =
67 AsmPrinter.MMI->getObjFileInfo<X86COFFMachineModuleInfo>();
68 COFFMMI.DecorateCygMingName(Sym, Ctx, cast<Function>(GV),
69 *AsmPrinter.TM.getTargetData());
70 Name.append(Sym->getName().begin(), Sym->getName().end());
72 const GlobalValue *GV = MO.getGlobal();
73 bool isImplicitlyPrivate = false;
74 if (MO.getTargetFlags() == X86II::MO_DARWIN_STUB ||
75 MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY ||
76 MO.getTargetFlags() == X86II::MO_DARWIN_NONLAZY_PIC_BASE ||
77 MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
78 isImplicitlyPrivate = true;
80 Mang->getNameWithPrefix(Name, GV, isImplicitlyPrivate);
83 // If the target flags on the operand changes the name of the symbol, do that
84 // before we return the symbol.
85 switch (MO.getTargetFlags()) {
87 case X86II::MO_DLLIMPORT: {
88 // Handle dllimport linkage.
89 const char *Prefix = "__imp_";
90 Name.insert(Name.begin(), Prefix, Prefix+strlen(Prefix));
93 case X86II::MO_DARWIN_NONLAZY:
94 case X86II::MO_DARWIN_NONLAZY_PIC_BASE: {
95 Name += "$non_lazy_ptr";
96 MCSymbol *Sym = Ctx.GetOrCreateTemporarySymbol(Name.str());
98 MachineModuleInfoImpl::StubValueTy &StubSym =
99 getMachOMMI().getGVStubEntry(Sym);
100 if (StubSym.getPointer() == 0) {
101 assert(MO.isGlobal() && "Extern symbol not handled yet");
103 MachineModuleInfoImpl::
104 StubValueTy(AsmPrinter.GetGlobalValueSymbol(MO.getGlobal()),
105 !MO.getGlobal()->hasInternalLinkage());
109 case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: {
110 Name += "$non_lazy_ptr";
111 MCSymbol *Sym = Ctx.GetOrCreateTemporarySymbol(Name.str());
112 MachineModuleInfoImpl::StubValueTy &StubSym =
113 getMachOMMI().getHiddenGVStubEntry(Sym);
114 if (StubSym.getPointer() == 0) {
115 assert(MO.isGlobal() && "Extern symbol not handled yet");
117 MachineModuleInfoImpl::
118 StubValueTy(AsmPrinter.GetGlobalValueSymbol(MO.getGlobal()),
119 !MO.getGlobal()->hasInternalLinkage());
123 case X86II::MO_DARWIN_STUB: {
125 MCSymbol *Sym = Ctx.GetOrCreateTemporarySymbol(Name.str());
126 MachineModuleInfoImpl::StubValueTy &StubSym =
127 getMachOMMI().getFnStubEntry(Sym);
128 if (StubSym.getPointer())
133 MachineModuleInfoImpl::
134 StubValueTy(AsmPrinter.GetGlobalValueSymbol(MO.getGlobal()),
135 !MO.getGlobal()->hasInternalLinkage());
137 Name.erase(Name.end()-5, Name.end());
139 MachineModuleInfoImpl::
140 StubValueTy(Ctx.GetOrCreateTemporarySymbol(Name.str()), false);
146 return Ctx.GetOrCreateSymbol(Name.str());
149 MCOperand X86MCInstLower::LowerSymbolOperand(const MachineOperand &MO,
150 MCSymbol *Sym) const {
151 // FIXME: We would like an efficient form for this, so we don't have to do a
152 // lot of extra uniquing.
153 const MCExpr *Expr = 0;
154 X86MCTargetExpr::VariantKind RefKind = X86MCTargetExpr::Invalid;
156 switch (MO.getTargetFlags()) {
157 default: llvm_unreachable("Unknown target flag on GV operand");
158 case X86II::MO_NO_FLAG: // No flag.
159 // These affect the name of the symbol, not any suffix.
160 case X86II::MO_DARWIN_NONLAZY:
161 case X86II::MO_DLLIMPORT:
162 case X86II::MO_DARWIN_STUB:
165 case X86II::MO_TLSGD: RefKind = X86MCTargetExpr::TLSGD; break;
166 case X86II::MO_GOTTPOFF: RefKind = X86MCTargetExpr::GOTTPOFF; break;
167 case X86II::MO_INDNTPOFF: RefKind = X86MCTargetExpr::INDNTPOFF; break;
168 case X86II::MO_TPOFF: RefKind = X86MCTargetExpr::TPOFF; break;
169 case X86II::MO_NTPOFF: RefKind = X86MCTargetExpr::NTPOFF; break;
170 case X86II::MO_GOTPCREL: RefKind = X86MCTargetExpr::GOTPCREL; break;
171 case X86II::MO_GOT: RefKind = X86MCTargetExpr::GOT; break;
172 case X86II::MO_GOTOFF: RefKind = X86MCTargetExpr::GOTOFF; break;
173 case X86II::MO_PLT: RefKind = X86MCTargetExpr::PLT; break;
174 case X86II::MO_PIC_BASE_OFFSET:
175 case X86II::MO_DARWIN_NONLAZY_PIC_BASE:
176 case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE:
177 Expr = MCSymbolRefExpr::Create(Sym, Ctx);
178 // Subtract the pic base.
179 Expr = MCBinaryExpr::CreateSub(Expr,
180 MCSymbolRefExpr::Create(GetPICBaseSymbol(), Ctx),
186 if (RefKind == X86MCTargetExpr::Invalid)
187 Expr = MCSymbolRefExpr::Create(Sym, Ctx);
189 Expr = X86MCTargetExpr::Create(Sym, RefKind, Ctx);
192 if (!MO.isJTI() && MO.getOffset())
193 Expr = MCBinaryExpr::CreateAdd(Expr,
194 MCConstantExpr::Create(MO.getOffset(), Ctx),
196 return MCOperand::CreateExpr(Expr);
201 static void lower_subreg32(MCInst *MI, unsigned OpNo) {
202 // Convert registers in the addr mode according to subreg32.
203 unsigned Reg = MI->getOperand(OpNo).getReg();
205 MI->getOperand(OpNo).setReg(getX86SubSuperRegister(Reg, MVT::i32));
208 static void lower_lea64_32mem(MCInst *MI, unsigned OpNo) {
209 // Convert registers in the addr mode according to subreg64.
210 for (unsigned i = 0; i != 4; ++i) {
211 if (!MI->getOperand(OpNo+i).isReg()) continue;
213 unsigned Reg = MI->getOperand(OpNo+i).getReg();
214 if (Reg == 0) continue;
216 MI->getOperand(OpNo+i).setReg(getX86SubSuperRegister(Reg, MVT::i64));
220 /// LowerSubReg32_Op0 - Things like MOVZX16rr8 -> MOVZX32rr8.
221 static void LowerSubReg32_Op0(MCInst &OutMI, unsigned NewOpc) {
222 OutMI.setOpcode(NewOpc);
223 lower_subreg32(&OutMI, 0);
225 /// LowerUnaryToTwoAddr - R = setb -> R = sbb R, R
226 static void LowerUnaryToTwoAddr(MCInst &OutMI, unsigned NewOpc) {
227 OutMI.setOpcode(NewOpc);
228 OutMI.addOperand(OutMI.getOperand(0));
229 OutMI.addOperand(OutMI.getOperand(0));
233 void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
234 OutMI.setOpcode(MI->getOpcode());
236 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
237 const MachineOperand &MO = MI->getOperand(i);
240 switch (MO.getType()) {
243 llvm_unreachable("unknown operand type");
244 case MachineOperand::MO_Register:
245 // Ignore all implicit register operands.
246 if (MO.isImplicit()) continue;
247 MCOp = MCOperand::CreateReg(MO.getReg());
249 case MachineOperand::MO_Immediate:
250 MCOp = MCOperand::CreateImm(MO.getImm());
252 case MachineOperand::MO_MachineBasicBlock:
253 MCOp = MCOperand::CreateExpr(MCSymbolRefExpr::Create(
254 MO.getMBB()->getSymbol(Ctx), Ctx));
256 case MachineOperand::MO_GlobalAddress:
257 MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
259 case MachineOperand::MO_ExternalSymbol:
260 MCOp = LowerSymbolOperand(MO, GetSymbolFromOperand(MO));
262 case MachineOperand::MO_JumpTableIndex:
263 MCOp = LowerSymbolOperand(MO, AsmPrinter.GetJTISymbol(MO.getIndex()));
265 case MachineOperand::MO_ConstantPoolIndex:
266 MCOp = LowerSymbolOperand(MO, AsmPrinter.GetCPISymbol(MO.getIndex()));
268 case MachineOperand::MO_BlockAddress:
269 MCOp = LowerSymbolOperand(MO,
270 AsmPrinter.GetBlockAddressSymbol(MO.getBlockAddress()));
274 OutMI.addOperand(MCOp);
277 // Handle a few special cases to eliminate operand modifiers.
278 switch (OutMI.getOpcode()) {
279 case X86::LEA64_32r: // Handle 'subreg rewriting' for the lea64_32mem operand.
280 lower_lea64_32mem(&OutMI, 1);
282 case X86::MOVZX16rr8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr8); break;
283 case X86::MOVZX16rm8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm8); break;
284 case X86::MOVSX16rr8: LowerSubReg32_Op0(OutMI, X86::MOVSX32rr8); break;
285 case X86::MOVSX16rm8: LowerSubReg32_Op0(OutMI, X86::MOVSX32rm8); break;
286 case X86::MOVZX64rr32: LowerSubReg32_Op0(OutMI, X86::MOV32rr); break;
287 case X86::MOVZX64rm32: LowerSubReg32_Op0(OutMI, X86::MOV32rm); break;
288 case X86::MOV64ri64i32: LowerSubReg32_Op0(OutMI, X86::MOV32ri); break;
289 case X86::MOVZX64rr8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr8); break;
290 case X86::MOVZX64rm8: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm8); break;
291 case X86::MOVZX64rr16: LowerSubReg32_Op0(OutMI, X86::MOVZX32rr16); break;
292 case X86::MOVZX64rm16: LowerSubReg32_Op0(OutMI, X86::MOVZX32rm16); break;
293 case X86::SETB_C8r: LowerUnaryToTwoAddr(OutMI, X86::SBB8rr); break;
294 case X86::SETB_C16r: LowerUnaryToTwoAddr(OutMI, X86::SBB16rr); break;
295 case X86::SETB_C32r: LowerUnaryToTwoAddr(OutMI, X86::SBB32rr); break;
296 case X86::SETB_C64r: LowerUnaryToTwoAddr(OutMI, X86::SBB64rr); break;
297 case X86::MOV8r0: LowerUnaryToTwoAddr(OutMI, X86::XOR8rr); break;
298 case X86::MOV32r0: LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); break;
299 case X86::MMX_V_SET0: LowerUnaryToTwoAddr(OutMI, X86::MMX_PXORrr); break;
300 case X86::MMX_V_SETALLONES:
301 LowerUnaryToTwoAddr(OutMI, X86::MMX_PCMPEQDrr); break;
302 case X86::FsFLD0SS: LowerUnaryToTwoAddr(OutMI, X86::PXORrr); break;
303 case X86::FsFLD0SD: LowerUnaryToTwoAddr(OutMI, X86::PXORrr); break;
304 case X86::V_SET0: LowerUnaryToTwoAddr(OutMI, X86::XORPSrr); break;
305 case X86::V_SETALLONES: LowerUnaryToTwoAddr(OutMI, X86::PCMPEQDrr); break;
308 LowerSubReg32_Op0(OutMI, X86::MOV32r0); // MOV16r0 -> MOV32r0
309 LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); // MOV32r0 -> XOR32rr
312 LowerSubReg32_Op0(OutMI, X86::MOV32r0); // MOV64r0 -> MOV32r0
313 LowerUnaryToTwoAddr(OutMI, X86::XOR32rr); // MOV32r0 -> XOR32rr
320 void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
321 X86MCInstLower MCInstLowering(OutContext, Mang, *this);
322 switch (MI->getOpcode()) {
323 case TargetOpcode::DBG_VALUE: {
324 // FIXME: if this is implemented for another target before it goes
325 // away completely, the common part should be moved into AsmPrinter.
328 O << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
329 unsigned NOps = MI->getNumOperands();
330 // cast away const; DIetc do not take const operands for some reason.
331 DIVariable V((MDNode*)(MI->getOperand(NOps-1).getMetadata()));
335 // Register or immediate value. Register 0 means undef.
336 assert(MI->getOperand(0).getType()==MachineOperand::MO_Register ||
337 MI->getOperand(0).getType()==MachineOperand::MO_Immediate ||
338 MI->getOperand(0).getType()==MachineOperand::MO_FPImmediate);
339 if (MI->getOperand(0).getType()==MachineOperand::MO_Register &&
340 MI->getOperand(0).getReg()==0) {
341 // Suppress offset in this case, it is not meaningful.
343 OutStreamer.AddBlankLine();
345 } else if (MI->getOperand(0).getType()==MachineOperand::MO_FPImmediate) {
346 // This is more naturally done in printOperand, but since the only use
347 // of such an operand is in this comment and that is temporary (and it's
348 // ugly), we prefer to keep this localized.
349 // The include of Type.h may be removable when this code is.
350 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy() ||
351 MI->getOperand(0).getFPImm()->getType()->isDoubleTy())
352 MI->getOperand(0).print(O, &TM);
354 // There is no good way to print long double. Convert a copy to
355 // double. Ah well, it's only a comment.
357 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
358 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
360 O << "(long double) " << APF.convertToDouble();
365 if (MI->getOperand(0).getType()==MachineOperand::MO_Register &&
366 MI->getOperand(0).getReg()==0) {
367 // Suppress offset in this case, it is not meaningful.
369 OutStreamer.AddBlankLine();
372 // Frame address. Currently handles register +- offset only.
373 assert(MI->getOperand(0).getType()==MachineOperand::MO_Register);
374 assert(MI->getOperand(3).getType()==MachineOperand::MO_Immediate);
375 O << '['; printOperand(MI, 0); O << '+'; printOperand(MI, 3); O << ']';
378 printOperand(MI, NOps-2);
379 OutStreamer.AddBlankLine();
382 case X86::MOVPC32r: {
384 // This is a pseudo op for a two instruction sequence with a label, which
391 MCSymbol *PICBase = MCInstLowering.GetPICBaseSymbol();
392 TmpInst.setOpcode(X86::CALLpcrel32);
393 // FIXME: We would like an efficient form for this, so we don't have to do a
394 // lot of extra uniquing.
395 TmpInst.addOperand(MCOperand::CreateExpr(MCSymbolRefExpr::Create(PICBase,
397 OutStreamer.EmitInstruction(TmpInst);
400 OutStreamer.EmitLabel(PICBase);
403 TmpInst.setOpcode(X86::POP32r);
404 TmpInst.getOperand(0) = MCOperand::CreateReg(MI->getOperand(0).getReg());
405 OutStreamer.EmitInstruction(TmpInst);
410 // Lower the MO_GOT_ABSOLUTE_ADDRESS form of ADD32ri.
411 if (MI->getOperand(2).getTargetFlags() != X86II::MO_GOT_ABSOLUTE_ADDRESS)
414 // Okay, we have something like:
415 // EAX = ADD32ri EAX, MO_GOT_ABSOLUTE_ADDRESS(@MYGLOBAL)
417 // For this, we want to print something like:
418 // MYGLOBAL + (. - PICBASE)
419 // However, we can't generate a ".", so just emit a new label here and refer
421 MCSymbol *DotSym = OutContext.GetOrCreateTemporarySymbol();
422 OutStreamer.EmitLabel(DotSym);
424 // Now that we have emitted the label, lower the complex operand expression.
425 MCSymbol *OpSym = MCInstLowering.GetSymbolFromOperand(MI->getOperand(2));
427 const MCExpr *DotExpr = MCSymbolRefExpr::Create(DotSym, OutContext);
428 const MCExpr *PICBase =
429 MCSymbolRefExpr::Create(MCInstLowering.GetPICBaseSymbol(), OutContext);
430 DotExpr = MCBinaryExpr::CreateSub(DotExpr, PICBase, OutContext);
432 DotExpr = MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(OpSym,OutContext),
433 DotExpr, OutContext);
436 TmpInst.setOpcode(X86::ADD32ri);
437 TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
438 TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(1).getReg()));
439 TmpInst.addOperand(MCOperand::CreateExpr(DotExpr));
440 OutStreamer.EmitInstruction(TmpInst);
446 MCInstLowering.Lower(MI, TmpInst);
448 OutStreamer.EmitInstruction(TmpInst);