Remove another unused flag.

[oota-llvm.git] / lib / Target / X86 / X86MCInstLower.cpp

diff --git a/lib/Target/X86/X86MCInstLower.cpp b/lib/Target/X86/X86MCInstLower.cpp
index 3fea4cb560e1e8764bd26ab1e9f61eada33cab19..bd2be3e6c9b3d103d7ec19ccf300d9165d193055 100644 (file)
--- a/lib/Target/X86/X86MCInstLower.cpp
+++ b/lib/Target/X86/X86MCInstLower.cpp
@@ -34,14 +34,12 @@ namespace {
 /// X86MCInstLower - This class is used to lower an MachineInstr into an MCInst.
 class X86MCInstLower {
   MCContext &Ctx;
-  Mangler *Mang;
   const MachineFunction &MF;
   const TargetMachine &TM;
   const MCAsmInfo &MAI;
   X86AsmPrinter &AsmPrinter;
 public:
-  X86MCInstLower(Mangler *mang, const MachineFunction &MF,
-                 X86AsmPrinter &asmprinter);
+  X86MCInstLower(const MachineFunction &MF, X86AsmPrinter &asmprinter);
 
   void Lower(const MachineInstr *MI, MCInst &OutMI) const;
 
@@ -50,13 +48,16 @@ public:
 
 private:
   MachineModuleInfoMachO &getMachOMMI() const;
+  Mangler *getMang() const {
+    return AsmPrinter.Mang;
+  }
 };
 
 } // end anonymous namespace
 
-X86MCInstLower::X86MCInstLower(Mangler *mang, const MachineFunction &mf,
+X86MCInstLower::X86MCInstLower(const MachineFunction &mf,
                                X86AsmPrinter &asmprinter)
-: Ctx(mf.getContext()), Mang(mang), MF(mf), TM(mf.getTarget()),
+: Ctx(mf.getContext()), MF(mf), TM(mf.getTarget()),
   MAI(*TM.getMCAsmInfo()), AsmPrinter(asmprinter) {}
 
 MachineModuleInfoMachO &X86MCInstLower::getMachOMMI() const {
@@ -81,7 +82,7 @@ GetSymbolFromOperand(const MachineOperand &MO) const {
         MO.getTargetFlags() == X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE)
       isImplicitlyPrivate = true;
 
-    Mang->getNameWithPrefix(Name, GV, isImplicitlyPrivate);
+    getMang()->getNameWithPrefix(Name, GV, isImplicitlyPrivate);
   } else if (MO.isSymbol()) {
     Name += MAI.getGlobalPrefix();
     Name += MO.getSymbolName();
@@ -110,7 +111,7 @@ GetSymbolFromOperand(const MachineOperand &MO) const {
       assert(MO.isGlobal() && "Extern symbol not handled yet");
       StubSym =
         MachineModuleInfoImpl::
-        StubValueTy(Mang->getSymbol(MO.getGlobal()),
+        StubValueTy(AsmPrinter.getSymbol(MO.getGlobal()),
                     !MO.getGlobal()->hasInternalLinkage());
     }
     return Sym;
@@ -124,7 +125,7 @@ GetSymbolFromOperand(const MachineOperand &MO) const {
       assert(MO.isGlobal() && "Extern symbol not handled yet");
       StubSym =
         MachineModuleInfoImpl::
-        StubValueTy(Mang->getSymbol(MO.getGlobal()),
+        StubValueTy(AsmPrinter.getSymbol(MO.getGlobal()),
                     !MO.getGlobal()->hasInternalLinkage());
     }
     return Sym;
@@ -140,7 +141,7 @@ GetSymbolFromOperand(const MachineOperand &MO) const {
     if (MO.isGlobal()) {
       StubSym =
         MachineModuleInfoImpl::
-        StubValueTy(Mang->getSymbol(MO.getGlobal()),
+        StubValueTy(AsmPrinter.getSymbol(MO.getGlobal()),
                     !MO.getGlobal()->hasInternalLinkage());
     } else {
       Name.erase(Name.end()-5, Name.end());
@@ -254,6 +255,34 @@ static void SimplifyShortImmForm(MCInst &Inst, unsigned Opcode) {
   Inst.addOperand(Saved);
 }
 
+/// \brief If a movsx instruction has a shorter encoding for the used register
+/// simplify the instruction to use it instead.
+static void SimplifyMOVSX(MCInst &Inst) {
+  unsigned NewOpcode = 0;
+  unsigned Op0 = Inst.getOperand(0).getReg(), Op1 = Inst.getOperand(1).getReg();
+  switch (Inst.getOpcode()) {
+  default:
+    llvm_unreachable("Unexpected instruction!");
+  case X86::MOVSX16rr8:  // movsbw %al, %ax   --> cbtw
+    if (Op0 == X86::AX && Op1 == X86::AL)
+      NewOpcode = X86::CBW;
+    break;
+  case X86::MOVSX32rr16: // movswl %ax, %eax  --> cwtl
+    if (Op0 == X86::EAX && Op1 == X86::AX)
+      NewOpcode = X86::CWDE;
+    break;
+  case X86::MOVSX64rr32: // movslq %eax, %rax --> cltq
+    if (Op0 == X86::RAX && Op1 == X86::EAX)
+      NewOpcode = X86::CDQE;
+    break;
+  }
+
+  if (NewOpcode != 0) {
+    Inst = MCInst();
+    Inst.setOpcode(NewOpcode);
+  }
+}
+
 /// \brief Simplify things like MOV32rm to MOV32o32a.
 static void SimplifyShortMoveForm(X86AsmPrinter &Printer, MCInst &Inst,
                                   unsigned Opcode) {
@@ -557,6 +586,13 @@ ReSimplify:
   case X86::XOR32ri:    SimplifyShortImmForm(OutMI, X86::XOR32i32);  break;
   case X86::XOR64ri32:  SimplifyShortImmForm(OutMI, X86::XOR64i32);  break;
 
+  // Try to shrink some forms of movsx.
+  case X86::MOVSX16rr8:
+  case X86::MOVSX32rr16:
+  case X86::MOVSX64rr32:
+    SimplifyMOVSX(OutMI);
+    break;
+
   case X86::MORESTACK_RET:
     OutMI.setOpcode(X86::RET);
     break;
@@ -651,7 +687,7 @@ static void LowerTlsAddr(MCStreamer &OutStreamer,
 }
 
 void X86AsmPrinter::EmitInstruction(const MachineInstr *MI) {
-  X86MCInstLower MCInstLowering(Mang, *MF, *this);
+  X86MCInstLower MCInstLowering(*MF, *this);
   switch (MI->getOpcode()) {
   case TargetOpcode::DBG_VALUE:
     llvm_unreachable("Should be handled target independently");