Hi All, I am new to GCC. I was working in an Embedded processor with GCC-4.6.4 version. I need to add load/store reverse instructions to the MD file. My instructions will look as below: LWX Rd,Ra,Rb operation: Addr := Ra + Rb Rd := *Addr (loading data with the opposite endianness) SWX Rd,Ra,Rb operation: Addr := Ra + Rb *Addr := Rd (storing data with the opposite endianness) To add the above instructions in to md file I tried below pattern in md file (define_insn "movsi_rev" [(set (match_operand:SI 0 "nonimmediate_operand" "=d,m") (bswap: SI (match_operand:SI 1 "move_src_operand" "m,d")))] "" "@ lwx\t%0,%1,%0 swx\t%0,%1,%0" [(set_attr "type" "load,store") (set_attr "mode" "SI") (set_attr "length" "4,4")]) I wrote a small testcase which is generating swx instruction but the operands are more due to which it is failing in assembler phase ex: instead of swx r0,r2,r0 it is generating swx r0,r2,0,r0 can anyone please help me in removing the extra operand in the above instruction. Thanks, Sravan