From 03b3668528ccfa4536c21702385aabcc3593d17c Mon Sep 17 00:00:00 2001
From: spth <spth@4a8a32a2-be11-0410-ad9d-d568d2c75423>
Date: Wed, 20 Feb 2008 15:51:15 +0000
Subject: [PATCH] Fixed bugs #1596270, #1736867

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@5028 4a8a32a2-be11-0410-ad9d-d568d2c75423
---
 ChangeLog     |  4 ++++
 src/z80/gen.c | 59 ++++++++++++++++++++++++++++++++++++++-------------
 2 files changed, 48 insertions(+), 15 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6666b199..f18af531 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2008-02-20 Philipp Klaus Krause <pkk AT spth.de>
+
+	* src/z80/gen.c: fixed bugs #1596270, #1736867
+
 2008-02-20 Philipp Klaus Krause <pkk AT spth.de>
 
 	* src/z80/gen.c: fixed bug in register pair loading when swapping register contents,
diff --git a/src/z80/gen.c b/src/z80/gen.c
index 97dfd410..9e995211 100644
--- a/src/z80/gen.c
+++ b/src/z80/gen.c
@@ -3922,28 +3922,57 @@ genPlus (iCode * ic)
 
   setupToPreserveCarry (ic);
 
-  while (size--)
+  /* This is ugly, but it fixes the worst code generation bug on Z80. */
+  /* Probably something similar has to be done for addition of larger numbers, too. */
+  if(size == 2)
     {
-      if (AOP_TYPE (IC_LEFT (ic)) == AOP_ACC)
+      _moveA (aopGet (AOP (IC_LEFT (ic)), 0, FALSE));
+      emit2 ("add a,%s", aopGet (AOP (IC_RIGHT (ic)), 0, FALSE));
+      if(strcmp (aopGet (AOP (IC_RESULT (ic)), 0, FALSE), aopGet (AOP (IC_LEFT (ic)), 1, FALSE)))
         {
-          _moveA (aopGet (AOP (IC_LEFT (ic)), offset, FALSE));
-          if (offset == 0)
-            emit2 ("add a,%s",
-                   aopGet (AOP (IC_RIGHT (ic)), offset, FALSE));
-          else
-            emit2 ("adc a,%s",
-                   aopGet (AOP (IC_RIGHT (ic)), offset, FALSE));
+          aopPut (AOP (IC_RESULT (ic)), "a", 0);
+          _moveA (aopGet (AOP (IC_LEFT (ic)), 1, FALSE));
         }
       else
         {
-          _moveA (aopGet (AOP (IC_LEFT (ic)), offset, FALSE));
-          if (offset == 0)
-            emit2 ("add a,%s",
-                   aopGet (AOP (IC_RIGHT (ic)), offset, FALSE));
+          emitDebug ("; Addition result is in same register as operand of next addition.");
+          if(strchr (aopGet (AOP (IC_RESULT (ic)), 0, FALSE), 'c') ||
+             strchr (aopGet (AOP (IC_RESULT (ic)), 0, FALSE), 'b') )
+            {
+              emit2 ("push de");
+              emit2 ("ld e, a");
+              emit2 ("ld a, %s", aopGet (AOP (IC_LEFT (ic)), 1, FALSE));
+              emit2 ("ld d, a");
+              emit2 ("ld a, e");
+              emit2 ("ld %s, a", aopGet (AOP (IC_RESULT (ic)), 0, FALSE));
+              emit2 ("ld a, d");
+              emit2 ("pop de");
+            }
           else
-            emit2 ("adc a,%s",
-                   aopGet (AOP (IC_RIGHT (ic)), offset, FALSE));
+            {
+              emit2 ("push bc");
+              emit2 ("ld c, a");
+              emit2 ("ld a, %s", aopGet (AOP (IC_LEFT (ic)), 1, FALSE));
+              emit2 ("ld b, a");
+              emit2 ("ld a, c");
+              emit2 ("ld %s, a", aopGet (AOP (IC_RESULT (ic)), 0, FALSE));
+              emit2 ("ld a, b");
+              emit2 ("pop bc");
+            }
+          
         }
+      emit2 ("adc a,%s", aopGet (AOP (IC_RIGHT (ic)), 1, FALSE));
+      aopPut (AOP (IC_RESULT (ic)), "a", 1);
+      goto release;
+    }
+
+  while (size--)
+    {
+      _moveA (aopGet (AOP (IC_LEFT (ic)), offset, FALSE));
+      if (offset == 0)
+        emit2 ("add a,%s", aopGet (AOP (IC_RIGHT (ic)), offset, FALSE));
+      else
+        emit2 ("adc a,%s", aopGet (AOP (IC_RIGHT (ic)), offset, FALSE));
       aopPut (AOP (IC_RESULT (ic)), "a", offset++);
     }
 
-- 
2.30.2