From 4eba8e12093c69e280d0c0809358d6f54a4ab9cf Mon Sep 17 00:00:00 2001
From: Astrid Smith
Date: Sat, 26 Jun 2010 13:47:25 -0700
Subject: Parted out ADC macro-instruction

---
 alu.asm     | 13 +++++++++++++
 main.asm    |  2 +-
 opcodes.asm | 14 ++++----------
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/alu.asm b/alu.asm
index 8fa4271..5f22b44 100644
--- a/alu.asm
+++ b/alu.asm
@@ -14,6 +14,19 @@ alu_add:
 	rts
 
 alu_adc:
+	;; ADC instruction
+	;; ADC d1,d0
+	;; d1 + d0 + carry -> d1
+	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)
+	add.b	d2,d1
+	move	sr,(f_host_ccr-flag_storage)(a3)
+	move.w	#$0202,(flag_byte-flag_storage)(a3)
+	rts
 
 alu_sbc:
 	;; SBC instruction
diff --git a/main.asm b/main.asm
index 0fcb31b..4a82d33 100644
--- a/main.asm
+++ b/main.asm
@@ -21,7 +21,7 @@
 ;;;
 ;;; D0 = current instruction, scratch for macros
 ;;; D1 = scratch for instructions
-;;; D2 = undefined
+;;; D2 = further scratch
 ;;;
 ;;;
 ;;; The following have their shadows in the top half of the register
diff --git a/opcodes.asm b/opcodes.asm
index 9154ec4..2301c71 100644
--- a/opcodes.asm
+++ b/opcodes.asm
@@ -1288,16 +1288,10 @@ emu_op_87:
 
 	;; Do an ADC \2,\1
 F_ADC_B	MACRO			; S34
-	;; 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)
-	add.b	d0,\2
-	move	sr,(f_host_ccr-flag_storage)(a3)
-	move.w	#$0202,(flag_byte-flag_storage)(a3)
+	move.b	\2,d1
+	move.b	\1,d0
+	bsr	alu_adc
+	move.b	d1,\2
 	ENDM
 
 	START
-- 
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