"Naveen H. S" <Naveen.S@xxxxxxxxxxxxxxx> writes: > Peephole pattern used to generate the tbit instruction and hence optmized code > ==================================================================================== > (define_peephole > [(set (match_operand:CR16IM 0 "register_operand" "") > (match_operand:CR16IM 1 "memory_operand" "")) > (set (match_dup 0) > (and:CR16IM (match_dup 0) > (match_operand 2 "const_int_operand" "v"))) > (parallel [(set (pc) > (if_then_else (match_operator 3 "ordered_comparison_operator" > [(match_dup 0) > (const_int 0)]) > (label_ref (match_operand 4 "" "")) > (pc))) > (clobber (cc0))])] > "TARGET_BIT_OPS && satisfies_constraint_v (operands[2])" > "tbit%t0\t$%s2,%1\;bf%o3\t%l4") This version is not checking whether operand[0] is dead. These days we generally recommend define_peephole2. If you use define_peephole as in this example, you need to use dead_or_set_p to check whether the register is dead. > Peephole2 pattern used to generate tbit instruction using far peep2_reg_dead_p > ==================================================================================== > (define_peephole2 > [(set (match_operand:CR16IM 0 "register_operand" "") > (match_operand:CR16IM 1 "memory_operand" "")) > (set (match_dup 0) > (and:CR16IM (match_dup 0) > (match_operand 2 "const_int_operand" "v"))) > (parallel [(set (pc) > (if_then_else (match_operator 3 "ordered_comparison_operator" > [(match_dup 0) > (const_int 0)]) > (label_ref (match_operand 4 "" "")) > (pc))) > (clobber (cc0))])] > "TARGET_BIT_OPS && satisfies_constraint_v (operands[2]) > && far peep2_reg_dead_p (2, operands[0])" > [(set (match_dup 0) > (unspec [(match_dup 1)(match_dup 2)] UNSPEC_TBIT)) > (set (match_dup 0) > (unspec [(match_operator 3 "" > [(match_dup 1) > (const_int 0)]) > (label_ref (match_dup 4)) > (match_dup 0)] UNSPEC_BRANCH))] > "" > ) As far as I can see, this version won't compile--there is an extraneous "far". Also, you are passing 2 to peep2_reg_dead_p. That is going to check whether the register is live in the second insn of the peephole, which it is: the second insn is the branch instruction, which tests the register. You need to pass 3 to peep2_reg_dead_p. By the way, you don't need to explicitly check satisfies_constraint_v in the peephold predicate, as that will be checked by the match_operand constraint. Ian
