diff -r 68578047307f -r ef18d64a1fb4 src/arch/x86/isa/decoder/x87.isa
--- a/src/arch/x86/isa/decoder/x87.isa	Tue Nov 03 16:55:16 2009 -0500
+++ b/src/arch/x86/isa/decoder/x87.isa	Thu Mar 17 16:00:40 2011 -0700
@@ -106,7 +106,7 @@
                     0x0: fprem();
                     0x1: fyl2xp1();
                     0x2: fsqrt();
-                    0x3: fsincos();
+                    0x3: Inst::FSINCOS();
                     0x4: frndint();
                     0x5: fscale();
                     0x6: fsin();
diff -r 68578047307f -r ef18d64a1fb4 src/arch/x86/isa/insts/x87/transcendental_functions/trigonometric_functions.py
--- a/src/arch/x86/isa/insts/x87/transcendental_functions/trigonometric_functions.py	Tue Nov 03 16:55:16 2009 -0500
+++ b/src/arch/x86/isa/insts/x87/transcendental_functions/trigonometric_functions.py	Thu Mar 17 16:00:40 2011 -0700
@@ -38,7 +38,14 @@
 microcode = '''
 # FSIN
 # FCOS
-# FSINCOS
+
+def macroop FSINCOS {
+    sinfp ufp1, st(0)
+    cosfp ufp2, st(0)
+    movfp st(0), ufp1
+    movfp st(-1), ufp2, spm=-1
+};
+
 # FPTAN
 # FPATAN
 '''
diff -r 68578047307f -r ef18d64a1fb4 src/arch/x86/isa/microops/fpop.isa
--- a/src/arch/x86/isa/microops/fpop.isa	Tue Nov 03 16:55:16 2009 -0500
+++ b/src/arch/x86/isa/microops/fpop.isa	Thu Mar 17 16:00:40 2011 -0700
@@ -223,6 +223,21 @@
     class Sqrtfp(FpOp):
         code = 'FpDestReg = sqrt(FpSrcReg2);'
 
+    class Cosfp(FpOp):
+        def __init__(self, dest, src1, spm=0, \
+                SetStatus=False, dataSize="env.dataSize"):
+            super(Cosfp, self).__init__(dest, src1, "InstRegIndex(0)", \
+                    spm, SetStatus, dataSize)
+        code = 'FpDestReg = cos(FpSrcReg1);'
+
+    class Sinfp(FpOp):
+        def __init__(self, dest, src1, spm=0, \
+                SetStatus=False, dataSize="env.dataSize"):
+            super(Sinfp, self).__init__(dest, src1, "InstRegIndex(0)", \
+                    spm, SetStatus, dataSize)
+        code = 'FpDestReg = sin(FpSrcReg1);'
+
+
     # Conversion microops
     class ConvOp(FpOp):
         abstract = True