1 files changed, 16 insertions, 1 deletions
diff --git a/src/arch/x86/isa/insts/x87/data_transfer_and_conversion/exchange.py b/src/arch/x86/isa/insts/x87/data_transfer_and_conversion/exchange.py
index 982ac8e55..b6fbb01cc 100644
--- a/src/arch/x86/isa/insts/x87/data_transfer_and_conversion/exchange.py
+++ b/src/arch/x86/isa/insts/x87/data_transfer_and_conversion/exchange.py
@@ -36,5 +36,20 @@
 # Authors: Gabe Black
 
 microcode = '''
-# FXCH
+def macroop FXCH_R
+{
+    movfp ufp1, sti
+    movfp sti, st(0)
+    movfp st(0), ufp1
+};
+
+def macroop FXCH_M
+{
+    fault "new UnimpInstFault"
+};
+
+def macroop FXCH_P
+{
+   fault "new UnimpInstFault"
+};
 '''