From 02cafbb3f0335e0fc8a673b97588c452d2fbf997 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Strohh=C3=A4cker?=
 <c2woody@users.sourceforge.net>
Date: Thu, 9 Oct 2008 20:37:08 +0000
Subject: [PATCH] adjust cycles for short-running string loops (thanks to
 ripsaw for pointing this out); fixes some gunship2000 flaws

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3229
---
 src/cpu/core_full/string.h   | 1 +
 src/cpu/core_normal/string.h | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/cpu/core_full/string.h b/src/cpu/core_full/string.h
index 0af58c1b..5da65b10 100644
--- a/src/cpu/core_full/string.h
+++ b/src/cpu/core_full/string.h
@@ -31,6 +31,7 @@
 			LoadIP();
 		} else {
 			/* Won't interrupt scas and cmps instruction since they can interrupt themselves */
+			if (inst.code.op<R_SCASB) CPU_Cycles-=count;
 			count_left=0;
 		}
 	}
diff --git a/src/cpu/core_normal/string.h b/src/cpu/core_normal/string.h
index a2639eb4..855397ad 100644
--- a/src/cpu/core_normal/string.h
+++ b/src/cpu/core_normal/string.h
@@ -34,8 +34,9 @@ static void DoString(STRING_OP type) {
 			CPU_Cycles=0;
 			LOADIP;		//RESET IP to the start
 		} else {
-			if ((count<=1) && (CPU_Cycles<=1)) CPU_Cycles--;
 			/* Won't interrupt scas and cmps instruction since they can interrupt themselves */
+			if ((count<=1) && (CPU_Cycles<=1)) CPU_Cycles--;
+			else if (type<R_SCASB) CPU_Cycles-=count;
 			count_left=0;
 		}
 	}