diff options
| author | Astrid Smith | 2010-06-07 13:44:08 -0700 |
|---|---|---|
| committer | Astrid Smith | 2010-06-07 13:44:08 -0700 |
| commit | 97738a65fc4a01a1e9d2972b77c2bace8cb0b5ed (patch) | |
| tree | dd5b45ce5585193babf4aa9f536c402ea6b0617f /main.asm | |
| parent | cb3f15a1544007cc555368ff67393cdec21362cf (diff) | |
New instructions, created some special purpose macros
Diffstat (limited to 'main.asm')
| -rw-r--r-- | main.asm | 81 |
1 files changed, 77 insertions, 4 deletions
@@ -34,6 +34,8 @@ xdef _nostub include "../tios.h" + ;; == Memory Macros ================================================ + ;; Macro to read a byte from main memory at register \1. Puts ;; the byte read in \2. FETCHB MACRO ; 14 cycles, 4 bytes @@ -59,6 +61,8 @@ PUTW MACRO ; 14 cycles, 4 bytes move.b \1,(\2,a6) ENDM + ;; == Immediate Memory Macros == + ;; Macro to read an immediate byte into \2. FETCHBI MACRO ; 18 cycles, 6 bytes addq.w #1,d2 ; 4/2 @@ -73,6 +77,8 @@ FETCHWI MACRO ; 36 cycles, 12 bytes move.b -2(d2.w,a6),\2 ; 14/4 ENDM + ;; == Common Opcode Macros ========================================= + ;; When you want to use the high reg of a pair, use this first LOHI MACRO ; 6 cycles, 2 bytes ror #8,\1 @@ -85,10 +91,39 @@ HILO MACRO ; 6 cycles, 2 bytes DONE MACRO ; 8 cycles, 2 bytes ;; calc84maniac suggests putting emu_fetch into this in order - ;; to save 8 cycles per instruction + ;; to save 8 cycles per instruction, at the expense of code + ;; size jmp (a2) ENDM + ;; == Special Opcode Macros ======================================== + + ;; Set flags appropriately for an ADD \1,\2 +F_ADD_B MACRO + ;; preserve operands for flagging + move.b \1,add_src + move.b \2,add_dst + moveq #0,flag_n + ;; XXX do I have to use SR instead? + move ccr,68k_ccr + ENDM + + ;; Set flags appropriately for a SUB \1,\2 +F_SUB_B MACRO + ENDM + + +;; ========================================================================= +;; +;; _ _ _ _ +;; __| (_)___ _ __ __ _| |_ ___| |__ +;; / _` | / __| '_ \ / _` | __/ __| '_ \ +;; | (_| | \__ \ |_) | (_| | || (__| | | | +;; \__,_|_|___/ .__/ \__,_|\__\___|_| |_| +;; |_| +;; +;; ========================================================================= + _main: @@ -125,6 +160,12 @@ emu_alt_fetch: jmp (a3,d0) ;14 cycles ;; overhead: 32 cycles +storage: +add_src: dc.b 0 +add_dst: dc.b 0 +flag_n: dc.b 0 +68k_ccr: dc.w 0 + ;;; ======================================================================== ;;; ======================================================================== ;;; ___ ___ ======= ============================== @@ -1287,16 +1328,48 @@ emu_op_7f: emu_op_80: ;; ADD A,B LOHI d4 - add.b d3,d4 - ;; preserve operands for flagging - move.b + F_ADD_B d4,d3 + add.b d4,d3 + HILO d4 + DONE emu_op_81: + ;; ADD A,C + F_ADD_B d4,d3 + add.b d4,d3 + DONE + emu_op_82: + ;; ADD A,D + LOHI d5 + F_ADD_B d5,d3 + add.b d5,d3 + HILO d5 + DONE + emu_op_83: + ;; ADD A,E + F_ADD_B d5,d3 + add.b d5,d3 + DONE + emu_op_84: + ;; ADD A,H + LOHI d6 + F_ADD_B d6,d3 + add.b d6,d3 + HILO d6 + DONE + emu_op_85: + ;; ADD A,L + F_ADD_B d6,d3 + add.b d6,d3 + DONE + emu_op_86: + ;; ADD A,(HL) + emu_op_87: emu_op_88: emu_op_89: |