1120   uint8_t REX = [&, MemOperand]() {  in emitREXPrefix()  local
1121     uint8_t REX = 0;  in emitREXPrefix()  local
1128       REX |= 1 << 3; // set REX.W  in emitREXPrefix()
1131       return REX;  in emitREXPrefix()
1147           REX |= 0x40; // REX fixed encoding prefix  in emitREXPrefix()
1157           REX |= 0x40; // REX fixed encoding prefix  in emitREXPrefix()
1164       REX |= isREXExtendedReg(MI, CurOp++) << 0; // REX.B  in emitREXPrefix()
1168       REX |= isREXExtendedReg(MI, CurOp++) << 2; // REX.R  in emitREXPrefix()
1169       REX |= isREXExtendedReg(MI, CurOp++) << 0; // REX.B  in emitREXPrefix()
1173       REX |= isREXExtendedReg(MI, CurOp++) << 2;                        // REX.R  in emitREXPrefix()
1174       REX |= isREXExtendedReg(MI, MemOperand + X86::AddrBaseReg) << 0;  // REX.B  in emitREXPrefix()
1175       REX |= isREXExtendedReg(MI, MemOperand + X86::AddrIndexReg) << 1; // REX.X  in emitREXPrefix()
1179       REX |= isREXExtendedReg(MI, CurOp++) << 0; // REX.B  in emitREXPrefix()
1180       REX |= isREXExtendedReg(MI, CurOp++) << 2; // REX.R  in emitREXPrefix()
1183       REX |= isREXExtendedReg(MI, MemOperand + X86::AddrBaseReg) << 0;  // REX.B  in emitREXPrefix()
1184       REX |= isREXExtendedReg(MI, MemOperand + X86::AddrIndexReg) << 1; // REX.X  in emitREXPrefix()
1186       REX |= isREXExtendedReg(MI, CurOp++) << 2; // REX.R  in emitREXPrefix()
1198       REX |= isREXExtendedReg(MI, MemOperand + X86::AddrBaseReg) << 0;  // REX.B  in emitREXPrefix()
1199       REX |= isREXExtendedReg(MI, MemOperand + X86::AddrIndexReg) << 1; // REX.X  in emitREXPrefix()
1211       REX |= isREXExtendedReg(MI, CurOp++) << 0; // REX.B  in emitREXPrefix()
1214       REX |= isREXExtendedReg(MI, CurOp++) << 2; // REX.R  in emitREXPrefix()
1219     if (REX && UsesHighByteReg)  in emitREXPrefix()
1222     return REX;  in emitREXPrefix()
1225   if (!REX)  in emitREXPrefix()
1228   emitByte(0x40 | REX, OS);  in emitREXPrefix()