SHF_OP_AND
reg_imm(0xf), SHF_OP_AND, reg_b(2), SHF_SC_R_SHF, 0);
reg_imm(0xf), SHF_OP_AND, reg_b(3), SHF_SC_R_SHF, 0);
reg_imm(0xff), SHF_OP_AND, reg_b(2), SHF_SC_R_SHF, 0);