From a4f4c415ac46b3ca54a85ea7f36d5e6d1f2b72af Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Wed, 19 Feb 2014 20:24:53 +0000
Subject: [PATCH] [FAST486] - When pushing 16-bit value, check only low word of
 ESP (i.e. SP). - Don't forget to clear high word of EIP, for the Jump
 instruction of group 4 (0xFF).

svn path=/branches/ntvdm/; revision=62258
---
 lib/fast486/common.inl | 2 +-
 lib/fast486/opgroups.c | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/fast486/common.inl b/lib/fast486/common.inl
index 97c5d4e309b..fff8fc01474 100644
--- a/lib/fast486/common.inl
+++ b/lib/fast486/common.inl
@@ -296,7 +296,7 @@ Fast486StackPush(PFAST486_STATE State,
         USHORT ShortValue = LOWORD(Value);
 
         /* Check if SP is 1 */
-        if (State->GeneralRegs[FAST486_REG_ESP].Long == 1)
+        if (State->GeneralRegs[FAST486_REG_ESP].LowWord == 1)
         {
             Fast486Exception(State, FAST486_EXCEPTION_SS);
             return FALSE;
diff --git a/lib/fast486/opgroups.c b/lib/fast486/opgroups.c
index 7480296a46e..0e560d5e151 100644
--- a/lib/fast486/opgroups.c
+++ b/lib/fast486/opgroups.c
@@ -1632,6 +1632,9 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeGroupFF)
         {
             /* Set the IP to the address */
             State->InstPtr.LowWord = Value;
+
+            /* Clear the top half of EIP */
+            State->InstPtr.Long &= 0xFFFF;
         }
         else if (ModRegRm.Register == 5)
         {