Added parity-calculation routine

1 files changed, 13 insertions, 3 deletions

diff --git a/flags.asm b/flags.asm
index a8f3b61..f316865 100644
--- a/flags.asm
+++ b/flags.asm
@@ -85,6 +85,18 @@ FNPV_ok:
 	andi.b	#%00000100,d1
 	rts
 
+	;; Calculate the P/V bit as Parity, for the byte in
+	;; d1. Destroys d0,d1.
+f_calc_parity:
+	andi.w	#$ff,d1
+	move.b	lut_parity(pc,d1),d1
+	move.w	flag_byte(pc),d0
+	and.b	#%11110111,d0
+	or.w	#%0000100000000000,d0
+	or.b	d1,d0
+	move.w	d0,flag_byte-flag_storage(a3)
+	rts
+
 	;; Normalize and return Sign bit (loaded into Z bit).
 	;; Destroys d1
 f_norm_sign:
@@ -126,10 +138,8 @@ f_tmp_src_w:	dc.w	0
 f_tmp_dst_w:	dc.w	0
 f_tmp_result_w:	dc.w	0
 
-flag_n:		dc.w	0
-
 	;; 000XNZVC
-	EVEN			; Compositing a word from two bytes ...
+	EVEN			; Compositing a word from two bytes
 f_host_sr:	dc.b	0
 f_host_ccr:	dc.b	0