Rebased PNaCl localmods in LLVM to 223109

lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp

Index: lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
diff --git a/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index 31b8e2da8e4e635646fb9c71f6e82ab5be0eea32..3ed7953d1d9501fce721f22978363708114e0ae1 100644
--- a/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -590,6 +590,8 @@ void X86MCCodeEmitter::EmitVEXOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
                                            int MemOperand, const MCInst &MI,
                                            const MCInstrDesc &Desc,
                                            raw_ostream &OS) const {
+  assert(!(TSFlags & X86II::LOCK)); // Can't have LOCK VEX. @LOCALMOD
+
   uint64_t Encoding = TSFlags & X86II::EncodingMask;
   bool HasEVEX_K = TSFlags & X86II::EVEX_K;
   bool HasVEX_4V = TSFlags & X86II::VEX_4V;
@@ -1109,6 +1111,12 @@ void X86MCCodeEmitter::EmitOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
                                                          : X86II::OpSize16))
     EmitByte(0x66, CurByte, OS);
 
+  // @LOCALMOD-START
+  // Emit the LOCK opcode prefix.
+  if (TSFlags & X86II::LOCK)
+    EmitByte(0xF0, CurByte, OS);
+  // @LOCALMOD-END
+
   switch (TSFlags & X86II::OpPrefixMask) {
   case X86II::PD:   // 66
     EmitByte(0x66, CurByte, OS);
@@ -1182,9 +1190,7 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
   int MemoryOperand = X86II::getMemoryOperandNo(TSFlags, Opcode);
   if (MemoryOperand != -1) MemoryOperand += CurOp;
 
-  // Emit the lock opcode prefix as needed.
-  if (TSFlags & X86II::LOCK)
-    EmitByte(0xF0, CurByte, OS);
+  // @LOCALMOD Moved LOCK prefix generation to EmitOpcodePrefix.
 
   // Emit segment override opcode prefix as needed.
   if (MemoryOperand >= 0)
@@ -1239,6 +1245,10 @@ EncodeInstruction(const MCInst &MI, raw_ostream &OS,
   switch (TSFlags & X86II::FormMask) {
   default: errs() << "FORM: " << (TSFlags & X86II::FormMask) << "\n";
     llvm_unreachable("Unknown FormMask value in X86MCCodeEmitter!");
+  // @LOCALMOD-BEGIN
+  case X86II::CustomFrm:
+    llvm_unreachable("CustomFrm instruction shouldn't be emitted");
+  // @LOCALMOD-END
   case X86II::Pseudo:
     llvm_unreachable("Pseudo instruction shouldn't be emitted");
   case X86II::RawFrmDstSrc: {