;; Machine Descriptions for R8C/M16C/M32C ;; Copyright (C) 2005-2021 Free Software Foundation, Inc. ;; Contributed by Red Hat. ;; ;; This file is part of GCC. ;; ;; GCC is free software; you can redistribute it and/or modify it ;; under the terms of the GNU General Public License as published ;; by the Free Software Foundation; either version 3, or (at your ;; option) any later version. ;; ;; GCC is distributed in the hope that it will be useful, but WITHOUT ;; ANY WARRANTY; without even the implied warranty of MERCHANTABILITY ;; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public ;; License for more details. ;; ;; You should have received a copy of the GNU General Public License ;; along with GCC; see the file COPYING3. If not see ;; http://www.gnu.org/licenses/.

; conditionals - cmp, jcc, setcc, etc.

; Special note about conditional instructions: GCC always emits the ; compare right before the insn, which is good, because m32c‘s mov ; insns modify the flags. However, this means that any conditional ; insn that may require reloading must be kept with its compare until ; after reload finishes, else the reload insns might clobber the ; flags. Thus, these rules: ; ; * the cmp* expanders just save the operands in compare_op0 and ; compare_op1 via m32c_pend_compare. ; * conditional insns that won’t need reload can call ; m32c_unpend_compare before their expansion. ; * other insns must expand to include the compare operands within, ; then split after reload to a separate compare and conditional.

; Until support for relaxing is supported in gas, we must assume that ; short labels won‘t reach, so we must use long labels. ; Unfortunately, there aren’t any conditional jumps with long labels, ; so instead we invert the conditional and jump around a regular jump.

; Note that we can, at some point in the future, add code to omit the ; “cmp” portion of the insn if the preceding insn happened to set the ; right flags already. For example, a mov followed by a “cmp *,0” is ; redundant; the move already set the Z flag.

(define_insn_and_split “cbranch4” [(set (pc) (if_then_else (match_operator 0 “m32c_cmp_operator” [(match_operand:QHPSI 1 “mra_operand” “RraSd”) (match_operand:QHPSI 2 “mrai_operand” “iRraSd”)]) (label_ref (match_operand 3 "" "")) (pc)))] "" “#” “reload_completed” [(set (reg:CC FLG_REGNO) (compare (match_dup 1) (match_dup 2))) (set (pc) (if_then_else (match_op_dup 0 [(reg:CC FLG_REGNO) (const_int 0)]) (label_ref (match_dup 3)) (pc)))] "" )

(define_insn “bcc_op” [(set (pc) (if_then_else (match_operator 0 “ordered_comparison_operator” [(reg:CC FLG_REGNO) (const_int 0)]) (label_ref (match_operand 1 "")) (pc)))] "" “j%c0\t%l1” [(set_attr “flags” “n”)] )

(define_insn “stzx_16” [(set (match_operand:QI 0 “register_operand” “=R0w,R0w,R0w”) (if_then_else:QI (eq (reg:CC FLG_REGNO) (const_int 0)) (match_operand:QI 1 “const_int_operand” “i,i,0”) (match_operand:QI 2 “const_int_operand” “i,0,i”)))] “TARGET_A16 && reload_completed” “@ stzx\t%1,%2,%0 stz\t%1,%0 stnz\t%2,%0” [(set_attr “flags” “n,n,n”)] )

(define_insn “stzx_24_” [(set (match_operand:QHI 0 “mra_operand” “=RraSd,RraSd,RraSd”) (if_then_else:QHI (eq (reg:CC FLG_REGNO) (const_int 0)) (match_operand:QHI 1 “const_int_operand” “i,i,0”) (match_operand:QHI 2 “const_int_operand” “i,0,i”)))] “TARGET_A24 && reload_completed” “@ stzx.\t%1,%2,%0 stz.\t%1,%0 stnz.\t%2,%0” [(set_attr “flags” “n,n,n”)])

(define_insn_and_split “stzx_reversed_” [(set (match_operand:QHI 0 “m32c_r0_operand” “=R0w”) (if_then_else:QHI (ne (reg:CC FLG_REGNO) (const_int 0)) (match_operand:QHI 1 “const_int_operand” "") (match_operand:QHI 2 “const_int_operand” "")))] “(TARGET_A24 || GET_MODE (operands[0]) == QImode) && reload_completed” “#” "" [(set (match_dup 0) (if_then_else:QHI (eq (reg:CC FLG_REGNO) (const_int 0)) (match_dup 2) (match_dup 1)))] "" )

(define_insn “cmp_op” [(set (reg:CC FLG_REGNO) (compare (match_operand:QHPSI 0 “mra_operand” “RraSd”) (match_operand:QHPSI 1 “mrai_operand” “RraSdi”)))] "" "* return m32c_output_compare(insn, operands); " [(set_attr “flags” “oszc”)])

;; m32c_conditional_register_usage changes the setcc_gen_code array to ;; point to the _24 variants if needed.

;; We need to keep the compare and conditional sets together through ;; reload, because reload might need to add address reloads to the ;; set, which would clobber the flags. By keeping them together, the ;; reloads get put before the compare, thus preserving the flags.

;; These are the post-split patterns for the conditional sets.

(define_insn “scc_op” [(set (match_operand:QI 0 “register_operand” “=Rqi”) (match_operator:QI 1 “ordered_comparison_operator” [(reg:CC FLG_REGNO) (const_int 0)]))] “TARGET_A16 && reload_completed” “* return m32c_scc_pattern(operands, GET_CODE (operands[1]));”)

(define_insn “scc_24_op” [(set (match_operand:HI 0 “mra_operand” “=RhiSd”) (match_operator:HI 1 “ordered_comparison_operator” [(reg:CC FLG_REGNO) (const_int 0)]))] “TARGET_A24 && reload_completed” “sc%c1\t%0” [(set_attr “flags” “n”)] )

;; These are the pre-split patterns for the conditional sets.

(define_expand “cstore4” [(set (match_operand:QI 0 “register_operand”) (match_operator:QI 1 “ordered_comparison_operator” [(match_operand:QHPSI 2 “mra_operand”) (match_operand:QHPSI 3 “mrai_operand”)]))] "" { if (TARGET_A24) { rtx o = gen_reg_rtx (HImode); emit_insn (gen_cstore4_24 (o, operands[1], operands[2], operands[3])); emit_move_insn (operands[0], gen_lowpart (QImode, o)); DONE; } })

(define_insn_and_split “*cstore4_16” [(set (match_operand:QI 0 “register_operand” “=Rqi”) (match_operator:QI 1 “ordered_comparison_operator” [(match_operand:QHPSI 2 “mra_operand” “RraSd”) (match_operand:QHPSI 3 “mrai_operand” “RraSdi”)]))] “TARGET_A16” “#” “&& reload_completed” [(set (reg:CC FLG_REGNO) (compare (match_dup 2) (match_dup 3))) (set (match_dup 0) (match_op_dup 1 [(reg:CC FLG_REGNO) (const_int 0)]))] "" [(set_attr “flags” “x”)] )

(define_insn_and_split “cstore4_24” [(set (match_operand:HI 0 “mra_nopp_operand” “=RhiSd”) (match_operator:HI 1 “ordered_comparison_operator” [(match_operand:QHPSI 2 “mra_operand” “RraSd”) (match_operand:QHPSI 3 “mrai_operand” “RraSdi”)]))] “TARGET_A24” “#” “&& reload_completed” [(set (reg:CC FLG_REGNO) (compare (match_dup 2) (match_dup 3))) (set (match_dup 0) (match_op_dup 1 [(reg:CC FLG_REGNO) (const_int 0)]))] "" [(set_attr “flags” “x”)] )

(define_insn_and_split “movqicc__” [(set (match_operand:QI 0 “register_operand” “=R0w”) (if_then_else:QI (eqne_cond (match_operand:QHPSI 1 “mra_operand” “RraSd”) (match_operand:QHPSI 2 “mrai_operand” “RraSdi”)) (match_operand:QI 3 “const_int_operand” "") (match_operand:QI 4 “const_int_operand” "")))] "" “#” “reload_completed” [(set (reg:CC FLG_REGNO) (compare (match_dup 1) (match_dup 2))) (set (match_dup 0) (if_then_else:QI (eqne_cond (reg:CC FLG_REGNO) (const_int 0)) (match_dup 3) (match_dup 4)))] "" [(set_attr “flags” “x”)] )

(define_insn_and_split “movhicc__” [(set (match_operand:HI 0 “register_operand” “=R0w”) (if_then_else:HI (eqne_cond (match_operand:QHPSI 1 “mra_operand” “RraSd”) (match_operand:QHPSI 2 “mrai_operand” “RraSdi”)) (match_operand:HI 3 “const_int_operand” "") (match_operand:HI 4 “const_int_operand” "")))] “TARGET_A24” “#” “reload_completed” [(set (reg:CC FLG_REGNO) (compare (match_dup 1) (match_dup 2))) (set (match_dup 0) (if_then_else:HI (eqne_cond (reg:CC FLG_REGNO) (const_int 0)) (match_dup 3) (match_dup 4)))] "" [(set_attr “flags” “x”)] )

;; And these are the expanders.

(define_expand “movqicc” [(set (match_operand:QI 0 “register_operand” "") (if_then_else:QI (match_operand 1 “m32c_eqne_operator” "") (match_operand:QI 2 “const_int_operand” "") (match_operand:QI 3 “const_int_operand” "")))] "" “if (m32c_expand_movcc(operands)) FAIL; DONE;” )

(define_expand “movhicc” [(set (match_operand:HI 0 “mra_operand” "") (if_then_else:HI (match_operand 1 “m32c_eqne_operator” "") (match_operand:HI 2 “const_int_operand” "") (match_operand:HI 3 “const_int_operand” "")))] “TARGET_A24” “if (m32c_expand_movcc(operands)) FAIL; DONE;” )

;; CMP opcodes subtract two values, set the flags, and discard the ;; value. This pattern recovers the sign of the discarded value based ;; on the flags. Operand 0 is set to -1, 0, or 1. This is used for ;; the cmpstr pattern. For optimal code, this should be removed if ;; followed by a suitable CMP insn (see the peephole following). This ;; pattern is 7 bytes and 5 cycles. If you don't need specific ;; values, a 5/4 pattern can be made with SCGT and BMLT to set the ;; appropriate bits.

(define_insn “cond_to_int” [(set (match_operand:HI 0 “mra_qi_operand” “=Rqi”) (if_then_else:HI (lt (reg:CC FLG_REGNO) (const_int 0)) (const_int -1) (if_then_else:HI (eq (reg:CC FLG_REGNO) (const_int 0)) (const_int 0) (const_int -1))))] “TARGET_A24” “sceq\t%0\n\tbmgt\t1,%h0\n\tdec.w\t%0” [(set_attr “flags” “x”)] )

;; A cond_to_int followed by a compare against zero is essentially a ;; no-op. However, the result of the cond_to_int may be used by later ;; insns, so make sure it's dead before deleting its set.

(define_peephole2 [(set (match_operand:HI 0 “mra_qi_operand” "") (if_then_else:HI (lt (reg:CC FLG_REGNO) (const_int 0)) (const_int -1) (if_then_else:HI (eq (reg:CC FLG_REGNO) (const_int 0)) (const_int 0) (const_int -1)))) (set (reg:CC FLG_REGNO) (compare (match_operand:HI 1 “mra_qi_operand” "") (const_int 0))) ] “rtx_equal_p (operands[0], operands[1]) && dead_or_set_p (peep2_next_insn (1), operands[0])” [(const_int 1)] "")