diff options
Diffstat (limited to 'main.asm')
| -rw-r--r-- | main.asm | 176 |
1 files changed, 2 insertions, 174 deletions
@@ -47,177 +47,6 @@ xdef _tigcc_native include "../tios.h" - ;; == Memory Macros ================================================ - - ;; Macro to read a byte from main memory at register \1. Puts - ;; the byte read in \2. -FETCHB MACRO - move.w \1,d1 - bsr deref - move.b (a0),\2 - ENDM - - ;; Macro to write a byte in \1 to main memory at \2 -PUTB MACRO - move.w \2,d1 - bsr deref - move.b \1,(a0) - ENDM - - ;; Macro to read a word from main memory at register \1 - ;; (unaligned). Puts the word read in \2. - ;; - ;; <debrouxl> It decrements sp by 2, but stores the result at - ;; sp, not at 1(sp). So you essentially get a "free" shift - ;; left by 8 bits. Much faster than lsl.w / rol.w #8, at - ;; least. -FETCHW MACRO ; ?/16 - move.w \1,d1 ; 4/2 - bsr deref ; ?/4 - move.b (a0),-(sp) ; 18/4 - move.w (sp)+,\2 ; 8/2 - move.b (a0),\2 ; 14/4 - ENDM - - ;; Macro to write a word in \1 to main memory at \2 (regs only) -PUTW MACRO ; - move.w \2,d1 - bsr deref - move.w \1,d0 - move.b d0,(a0)+ - LOHI d0 - move.b d0,(a0) - ENDM - - ;; Push the word in \1 (register) using stack register a4. - ;; Sadly, I can't trust the stack register to be aligned. - ;; Destroys d0. - - ;; (SP-2) <- \1_l - ;; (SP-1) <- \1_h - ;; SP <- SP - 2 -PUSHW MACRO - move.w \1,d0 - LOHI d0 ;slow - move.b d0,-(a4) ; high byte - move.b \1,-(a4) ; low byte - ENDM - - ;; Pop the word at the top of stack a4 into \1. - ;; Destroys d0. - - ;; \1_h <- (SP+1) - ;; \1_l <- (SP) - ;; SP <- SP + 2 -POPW MACRO - move.b (a4)+,\1 - LOHI \1 ;slow - move.b (a4)+,\1 ; high byte - HILO \1 ;slow - ENDM - - ;; == Immediate Memory Macros == - - ;; Macro to read an immediate byte into \1. -FETCHBI MACRO ; 8 cycles, 2 bytes - move.b (a6)+,\1 ; 8/2 - ENDM - - ;; Macro to read an immediate word (unaligned) into \1. -FETCHWI MACRO ; 28 cycles, 6 bytes - ;; See FETCHW for an explanation of this trick. - move.b (a6)+,-(sp) ; 12/2 - move.w (sp)+,\1 ; 8/2 - move.b (a6)+,\1 ; 8/2 - ENDM ; 28/6 - - ;; == Common Opcode Macros ========================================= - - ;; To align subroutines. -_align SET 0 - -START MACRO - ORG emu_plain_op+_align -_align SET _align+$20 - ENDM - - ;; LOHI/HILO are hideously slow for instructions used often. - ;; Interleave registers instead: - ;; - ;; d4 = [B' B C' C] - ;; - ;; Thus access to B is fast (swap d4) while access to BC is - ;; slow. - - ;; When you want to use the high reg of a pair, use this first -LOHI MACRO ; 22 cycles, 2 bytes - ror.w #8,\1 ; 22/2 - ENDM - - ;; Then do your shit and finish with this -HILO MACRO ; 22 cycles, 2 bytes - rol.w #8,\1 - ENDM - - ;; Rearrange a register: ABCD -> ACBD. -WORD MACRO - move.l \1,-(a7) ;12 cycles / 2 bytes - movep.w 0(a7),\1 ;16 cycles / 4 bytes - swap \1 ; 4 cycles / 2 bytes - movep.w 1(a7),\1 ;16 cycles / 4 bytes - addq #4,a7 ; 4 cycles / 2 bytes - ;; overhead: 52 cycles /14 bytes - ENDM - - - ;; This is run at the end of every instruction routine. -DONE MACRO - clr.w d0 ; 4 cycles / 2 bytes - move.b (a4)+,d0 ; 8 cycles / 2 bytes - rol.w #5,d0 ;16 cycles / 2 bytes - jmp 0(a5,d0.w) ;14 cycles / 4 bytes - ;; overhead: 42 cycles /10 bytes - ENDM - - ;; == Special Opcode Macros ======================================== - - ;; Do an ADD \1,\2 -F_ADD_W MACRO - ENDM - ;; Do an SUB \1,\2 -F_SUB_W MACRO - ENDM - - ;; INC and DEC macros -F_INC_B MACRO - move.b #1,f_tmp_byte-flag_storage(a3) - move.b #1,f_tmp_src_b-flag_storage(a3) - move.b \1,f_tmp_dst_b-flag_storage(a3) - addq #1,\1 - moveq #2,d0 - F_CLEAR d0 - F_OVFL - ENDM - -F_DEC_B MACRO - move.b #1,f_tmp_byte-flag_storage(a3) - st f_tmp_src_b-flag_storage(a3) - move.b \1,f_tmp_dst_b-flag_storage(a3) - subq #1,\1 - F_SET #2 - ENDM - -F_INC_W MACRO - addq.w #1,\1 - ENDM - -F_DEC_W MACRO - subq.w #1,\1 - ENDM - - ;; I might be able to unify rotation flags or maybe use a - ;; lookup table - __main: @@ -323,14 +152,13 @@ underef_thatsit: ;; ========== ======================================================== ;; ========================================================================= + include "opcodes.asm" + emu_run: ;; XXX: make this actually return DONE rts - include "opcodes.asm" - - emu_op_undo_cb: emu_op_undo_dd: emu_op_undo_ed: |