From 5ef420af5a4be4350780b335354093bedc81b5c0 Mon Sep 17 00:00:00 2001
From: acqn <acqn163@outlook.com>
Date: Tue, 1 Mar 2022 10:40:01 +0800
Subject: [PATCH] Fixed OptCmp1 with certain code patterns with labels.

---
 src/cc65/coptcmp.c |  4 ++--
 test/val/bug1690.c | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 test/val/bug1690.c

diff --git a/src/cc65/coptcmp.c b/src/cc65/coptcmp.c
index fda23ae0a..92401a858 100644
--- a/src/cc65/coptcmp.c
+++ b/src/cc65/coptcmp.c
@@ -309,10 +309,10 @@ unsigned OptCmp1 (CodeSeg* S)
 
             /* Insert the ora instead */
             X = NewCodeEntry (OP65_ORA, L[0]->AM, L[0]->Arg, 0, L[0]->LI);
-            CS_InsertEntry (S, X, I);
+            CS_InsertEntry (S, X, I+3);
 
             /* Remove all other instructions */
-            CS_DelEntries (S, I+1, 3);
+            CS_DelEntries (S, I, 3);
 
             /* Remember, we had changes */
             ++Changes;
diff --git a/test/val/bug1690.c b/test/val/bug1690.c
new file mode 100644
index 000000000..317913634
--- /dev/null
+++ b/test/val/bug1690.c
@@ -0,0 +1,23 @@
+/* OptCmp1 messed up with labels */
+
+#include <stdio.h>
+
+int main(void)
+{
+    register unsigned int x = 0x200;
+    register unsigned int y = 0;
+
+    do
+    {
+        ++y;
+    }
+    while (--x);
+
+    if (y != 0x200)
+	{
+		printf("0x%X\n", y);
+		return 1;
+	}
+
+	return 0;
+}