diff options
Diffstat (limited to 'flags.asm')
| -rw-r--r-- | flags.asm | 32 |
1 files changed, 23 insertions, 9 deletions
@@ -17,15 +17,16 @@ F_CLEAR MACRO ;; Sets or clears the bit explicitly. ;; ;; Byte for which parity is calculated must be in \1. High - ;; byte of \1.w must be zero, using d0 is suggested. (d1 + ;; byte of \1.w must be zero, using d0 is suggested. (a0,d1 ;; destroyed) F_PAR MACRO - ori.b #%00000100,flag_valid-flag_storage(a3) ; ??/4 - move.b flag_byte-flag_storage(a3),d1 ; ??/2 - andi.b #%11111011,d1 ; ??/4 - or.b lut_parity-flag_storage(a3,\1.w),d1 ; ??/4 - move.b d1,flag_byte-flag_storage(a3) ; ??/2 + ori.b #%00000100,(flag_valid).w ; ??/4 + move.b (flag_byte).w,d1 ; ??/2 + andi.b #%11111011,d1 ; ??/4 + lea (lut_parity).w,a0 + or.b 0(a0,\1.w),d1 ; ??/4 + move.b d1,(flag_byte).w ; ??/2 ENDM ;xxx cycles (!) @@ -37,9 +38,9 @@ F_OVFL MACRO ;; Save the two operands from ADD \1,\2 F_ADD_SAVE MACRO - move.b \1,f_tmp_src_b-flag_storage(a3) - move.b \2,f_tmp_dst_b-flag_storage(a3) - move.b #$01,f_tmp_byte-flag_storage(a3) + move.b \1,(f_tmp_src_b).w + move.b \2,(f_tmp_dst_b).w + move.b #$01,(f_tmp_byte).w F_SET #% ENDM @@ -84,6 +85,18 @@ FNPV_ok: andi.b #%00000100,d1 rts + ;; Normalize and return Sign bit (loaded into Z bit). + ;; Destroys d1 +f_norm_sign: + move.b flag_valid-flag_storage(a3),d1 + andi.b #%01000000,d1 + bne.s FNsign_ok ; Bit is already valid + bsr flags_normalize +FNsign_ok: + move.b flag_byte-flag_storage(a3),d1 + andi.b #%01000000,d1 + rts + ;; Routine to turn 68k flags into z80 flags. ;; Preconditions: ;; Flags to change are noted in d0 by a 1 bit @@ -119,6 +132,7 @@ f_host_sr: ds.b 0 f_host_ccr: ds.b 0 EVEN + ;; DO NOT REARRANGE THESE. flag_byte: ds.b 0 ; Byte of all flags flag_valid: ds.b 0 ; Validity mask -- 1 if valid. |