Index: llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
===================================================================
--- llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ llvm/trunk/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -459,21 +459,18 @@
 
   // VFP and NEON instructions, similarly, are shared between ARM
   // and Thumb modes.
-  MI.clear();
   Result = decodeInstruction(DecoderTableVFP32, MI, Insn, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
     Size = 4;
     return Result;
   }
 
-  MI.clear();
   Result = decodeInstruction(DecoderTableVFPV832, MI, Insn, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
     Size = 4;
     return Result;
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTableNEONData32, MI, Insn, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -485,7 +482,6 @@
     return Result;
   }
 
-  MI.clear();
   Result = decodeInstruction(DecoderTableNEONLoadStore32, MI, Insn, Address,
                              this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -497,7 +493,6 @@
     return Result;
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTableNEONDup32, MI, Insn, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -509,7 +504,6 @@
     return Result;
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTablev8NEON32, MI, Insn, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -517,7 +511,6 @@
     return Result;
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTablev8Crypto32, MI, Insn, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -525,7 +518,6 @@
     return Result;
   }
 
-  MI.clear();
   Size = 0;
   return MCDisassembler::Fail;
 }
@@ -718,7 +710,6 @@
     return Result;
   }
 
-  MI.clear();
   Result = decodeInstruction(DecoderTableThumbSBit16, MI, Insn16, Address, this,
                              STI);
   if (Result) {
@@ -729,7 +720,6 @@
     return Result;
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTableThumb216, MI, Insn16, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -763,7 +753,6 @@
 
   uint32_t Insn32 =
       (Bytes[3] << 8) | (Bytes[2] << 0) | (Bytes[1] << 24) | (Bytes[0] << 16);
-  MI.clear();
   Result =
       decodeInstruction(DecoderTableThumb32, MI, Insn32, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -774,7 +763,6 @@
     return Result;
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTableThumb232, MI, Insn32, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -784,7 +772,6 @@
   }
 
   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
-    MI.clear();
     Result =
         decodeInstruction(DecoderTableVFP32, MI, Insn32, Address, this, STI);
     if (Result != MCDisassembler::Fail) {
@@ -794,7 +781,6 @@
     }
   }
 
-  MI.clear();
   Result =
       decodeInstruction(DecoderTableVFPV832, MI, Insn32, Address, this, STI);
   if (Result != MCDisassembler::Fail) {
@@ -803,7 +789,6 @@
   }
 
   if (fieldFromInstruction(Insn32, 28, 4) == 0xE) {
-    MI.clear();
     Result = decodeInstruction(DecoderTableNEONDup32, MI, Insn32, Address, this,
                                STI);
     if (Result != MCDisassembler::Fail) {
@@ -814,7 +799,6 @@
   }
 
   if (fieldFromInstruction(Insn32, 24, 8) == 0xF9) {
-    MI.clear();
     uint32_t NEONLdStInsn = Insn32;
     NEONLdStInsn &= 0xF0FFFFFF;
     NEONLdStInsn |= 0x04000000;
@@ -828,7 +812,6 @@
   }
 
   if (fieldFromInstruction(Insn32, 24, 4) == 0xF) {
-    MI.clear();
     uint32_t NEONDataInsn = Insn32;
     NEONDataInsn &= 0xF0FFFFFF; // Clear bits 27-24
     NEONDataInsn |= (NEONDataInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
@@ -841,7 +824,6 @@
       return Result;
     }
 
-    MI.clear();
     uint32_t NEONCryptoInsn = Insn32;
     NEONCryptoInsn &= 0xF0FFFFFF; // Clear bits 27-24
     NEONCryptoInsn |= (NEONCryptoInsn & 0x10000000) >> 4; // Move bit 28 to bit 24
@@ -853,7 +835,6 @@
       return Result;
     }
 
-    MI.clear();
     uint32_t NEONv8Insn = Insn32;
     NEONv8Insn &= 0xF3FFFFFF; // Clear bits 27-26
     Result = decodeInstruction(DecoderTablev8NEON32, MI, NEONv8Insn, Address,
@@ -864,7 +845,6 @@
     }
   }
 
-  MI.clear();
   Size = 0;
   return MCDisassembler::Fail;
 }
Index: llvm/trunk/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
===================================================================
--- llvm/trunk/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
+++ llvm/trunk/lib/Target/Hexagon/Disassembler/HexagonDisassembler.cpp
@@ -235,6 +235,7 @@
   Size = 0;
 
   *CurrentBundle = &MI;
+  MI.clear();
   MI.setOpcode(Hexagon::BUNDLE);
   MI.addOperand(MCOperand::createImm(0));
   while (Result == Success && Complete == false) {
Index: llvm/trunk/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
===================================================================
--- llvm/trunk/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
+++ llvm/trunk/lib/Target/PowerPC/Disassembler/PPCDisassembler.cpp
@@ -401,8 +401,6 @@
       decodeInstruction(DecoderTableQPX32, MI, Inst, Address, this, STI);
     if (result != MCDisassembler::Fail)
       return result;
-
-    MI.clear();
   }
 
   return decodeInstruction(DecoderTable32, MI, Inst, Address, this, STI);
Index: llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp
===================================================================
--- llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ llvm/trunk/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -962,6 +962,7 @@
     return true;
   }
 
+  mcInst.clear();
   mcInst.setOpcode(insn.instructionID);
   // If when reading the prefix bytes we determined the overlapping 0xf2 or 0xf3
   // prefix bytes should be disassembled as xrelease and xacquire then set the
Index: llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp
===================================================================
--- llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp
+++ llvm/trunk/utils/TableGen/FixedLenDecoderEmitter.cpp
@@ -2170,6 +2170,7 @@
      << "      unsigned DecodeIdx = decodeULEB128(Ptr, &Len);\n"
      << "      Ptr += Len;\n"
      << "\n"
+     << "      MI.clear();\n"
      << "      MI.setOpcode(Opc);\n"
      << "      bool DecodeComplete;\n"
      << "      S = decodeToMCInst(S, DecodeIdx, insn, MI, Address, DisAsm, DecodeComplete);\n"