From 5728b3249ba24a47b836053584f2b9e9eeab1453 Mon Sep 17 00:00:00 2001
From: Astrid Smith
Date: Mon, 21 Jun 2010 14:51:44 -0700
Subject: Parted out F_SBC_B to alu_sbc.

---
 alu.asm     | 19 ++++++++++++++++++-
 opcodes.asm | 15 ++++-----------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/alu.asm b/alu.asm
index cce4011..18f5260 100644
--- a/alu.asm
+++ b/alu.asm
@@ -1,4 +1,21 @@
 	;; Parting out the big math/logic routines from the
 	;; instruction dispatch table.
 
-	
+alu_sbc:
+	;; SBC instruction
+	;; SBC d1,d0
+	;; d1 - (d0+C) -> d1
+	;; sets flags
+
+	push.l	d2
+	bsr	flags_normalize
+	move.b	flag_byte(pc),d2
+	andi.b	#1,d2
+	add.b	d0,d2
+	move.b	d2,(f_tmp_src_b-flag_storage)(a3)
+	move.b	d1,(f_tmp_dst_b-flag_storage)(a3)
+	sub.b	d2,d1
+	move	sr,(f_host_sr-flag_storage)(a3)
+	move.w	#$0202,(flag_byte-flag_storage)(a3)
+	pop.l	d2
+	rts
diff --git a/opcodes.asm b/opcodes.asm
index 9b550ea..35a7f4f 100644
--- a/opcodes.asm
+++ b/opcodes.asm
@@ -1439,17 +1439,10 @@ emu_op_97:
 
 	;; Do a SBC \2,\1
 F_SBC_B	MACRO
-	;; XXX TOO BIG
-	bsr	flags_normalize
-	move.b	flag_byte(pc),d0
-	andi.b	#1,d0
-	add.b	\1,d0
-	move.b	d0,(f_tmp_src_b-flag_storage)(a3)
-	move.b	\2,(f_tmp_dst_b-flag_storage)(a3)
-	sub.b	d0,\2
-	move	sr,(f_host_sr-flag_storage)(a3)
-	move.w	#$0202,(flag_byte-flag_storage)(a3)
-
+	move.b	\2,d1
+	move.b	\1,d0
+	bsr	alu_sbc
+	move.b	d1,\2
 	ENDM
 
 	START
-- 
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