diff options
Diffstat (limited to 'alu.s')
| -rw-r--r-- | alu.s | 51 |
1 files changed, 26 insertions, 25 deletions
@@ -1,13 +1,14 @@ - ;; Parting out the big math/logic routines from the - ;; instruction dispatch table. + || -*- gas -*- + || Parting out the big math/logic routines from the + || instruction dispatch table. .text alu_add: - ;; ADD instruction - ;; ADD d1,d0 - ;; d1 + d0 -> d1 - move.b d0,f_tmp_src_b ; preserve operands for flag work + || ADD instruction + || ADD d1,d0 + || d1 + d0 -> d1 + move.b d0,f_tmp_src_b | preserve operands for flag work move.b d1,f_tmp_dst_b move.b #1,f_tmp_byte add d0,d1 @@ -16,9 +17,9 @@ alu_add: rts alu_adc: - ;; ADC instruction - ;; ADC d1,d0 - ;; d1 + d0 + carry -> d1 + || ADC instruction + || ADC d1,d0 + || d1 + d0 + carry -> d1 bsr flags_normalize move.b flag_byte(pc),d2 andi.b #1,d2 @@ -31,10 +32,10 @@ alu_adc: rts alu_sbc: - ;; SBC instruction - ;; SBC d1,d0 - ;; d1 - (d0+C) -> d1 - ;; sets flags + || SBC instruction + || SBC d1,d0 + || d1 - (d0+C) -> d1 + || sets flags push.l d2 bsr flags_normalize @@ -51,14 +52,14 @@ alu_sbc: rts alu_sub: - ;; SUB instruction - ;; SUB d1,d0 - ;; d1 - d0 -> d1 - ;; sets flags + || SUB instruction + || SUB d1,d0 + || d1 - d0 -> d1 + || sets flags - ;; XXX use lea and then d(an) if you have a spare register. + || XXX use lea and then d(an) if you have a spare register. - ;; preserve operands for flagging + || preserve operands for flagging move.b d0,f_tmp_src_b move.b d1,f_tmp_dst_b move.b #1,f_tmp_byte @@ -69,22 +70,22 @@ alu_sub: rts alu_and: - ;; XXX do this + || XXX do this rts alu_xor: - ;; XXX do this + || XXX do this rts alu_or: - ;; XXX do this + || XXX do this rts alu_cp: - ;; Same as SUB but the macro that calls this doesn't save the - ;; result. + || Same as SUB but the macro that calls this doesn't save the + || result. - ;; SPEED can hardcode one of the arguments to always be the A register. + || SPEED can hardcode one of the arguments to always be the A register. move.b d0,f_tmp_src_b move.b d1,f_tmp_dst_b move.b #1,f_tmp_byte |