8 files changed, 36 insertions, 4 deletions

diff --git a/src/arch/x86/floatregfile.hh b/src/arch/x86/floatregfile.hh
index 14dda443f..b77ddb0eb 100644
--- a/src/arch/x86/floatregfile.hh
+++ b/src/arch/x86/floatregfile.hh
@@ -101,8 +101,9 @@ namespace X86ISA
     std::string getFloatRegName(RegIndex);
 
     //Each 128 bit xmm register is broken into two effective 64 bit registers.
-    const int NumFloatArchRegs = NumMMXRegs + 2 * NumXMMRegs + NumMicroFpRegs;
-    const int NumFloatRegs = NumFloatArchRegs;
+    const int NumFloatRegs =
+        NumMMXRegs + 2 * NumXMMRegs + NumMicroFpRegs;
+    const int NumFloatArchRegs = NumFloatRegs + 8;
 
     class FloatRegFile
     {
diff --git a/src/arch/x86/floatregs.hh b/src/arch/x86/floatregs.hh
index b9d6a5c43..30846ec00 100644
--- a/src/arch/x86/floatregs.hh
+++ b/src/arch/x86/floatregs.hh
@@ -162,6 +162,12 @@ namespace X86ISA
     {
         return (FloatRegIndex)(FLOATREG_MICROFP_BASE + index);
     }
+
+    static inline FloatRegIndex
+    FLOATREG_STACK(int index, int top)
+    {
+        return (FloatRegIndex)(NUM_FLOATREGS + ((top - index + 8) % 8));
+    }
 };
 
 #endif // __ARCH_X86_FLOATREGS_HH__
diff --git a/src/arch/x86/isa/microasm.isa b/src/arch/x86/isa/microasm.isa
index 579909506..e961cc63c 100644
--- a/src/arch/x86/isa/microasm.isa
+++ b/src/arch/x86/isa/microasm.isa
@@ -136,5 +136,10 @@ let {{
 
     assembler.symbols["label"] = labeler
 
+    def stack_index(index):
+        return "(NUM_FLOATREGS + (%s))" % index
+
+    assembler.symbols["st"] = stack_index
+
     macroopDict = assembler.assemble(microcode)
 }};
diff --git a/src/arch/x86/isa/operands.isa b/src/arch/x86/isa/operands.isa
index 7b0427b44..05a9f4418 100644
--- a/src/arch/x86/isa/operands.isa
+++ b/src/arch/x86/isa/operands.isa
@@ -115,6 +115,9 @@ def operands {{
         'uIP':           ('UPC', 'uqw', None, (None, None, 'IsControl'), 51),
         'nuIP':          ('NUPC', 'uqw', None, (None, None, 'IsControl'), 52),
         'ccFlagBits':    ('IntReg', 'uqw', 'INTREG_PSEUDO(0)', None, 60),
+        # The TOP register should needs to be more protected so that later
+        # instructions don't map their indexes with an old value.
+        'TOP':           ('ControlReg', 'ub', 'MISCREG_X87_TOP', None, 61),
         'SegBase':       ('ControlReg', 'uqw', 'MISCREG_SEG_BASE(segment)', (None, None, ['IsSerializeAfter','IsSerializing','IsNonSpeculative']), 70),
         'Mem':           ('Mem', 'uqw', None, ('IsMemRef', 'IsLoad', 'IsStore'), 100)
 }};
diff --git a/src/arch/x86/isa_traits.hh b/src/arch/x86/isa_traits.hh
index 602c99390..f3478d7f6 100644
--- a/src/arch/x86/isa_traits.hh
+++ b/src/arch/x86/isa_traits.hh
@@ -89,7 +89,9 @@ namespace X86ISA
             //mmx/x87 registers
             8 +
             //xmm registers
-            16
+            16 +
+            //The indices that are mapped over the fp stack
+            8
     };
 
     // semantically meaningful register indices
diff --git a/src/arch/x86/miscregs.hh b/src/arch/x86/miscregs.hh
index 01499e7ad..bab813719 100644
--- a/src/arch/x86/miscregs.hh
+++ b/src/arch/x86/miscregs.hh
@@ -171,9 +171,12 @@ namespace X86ISA
         MISCREG_LDTR_ATTR = MISCREG_SYSSEG_ATTR_BASE,
         MISCREG_TR_ATTR,
 
+        // Floating point control registers
+        MISCREG_X87_TOP = MISCREG_SYSSEG_ATTR_BASE + NumSysSegments,
+
         //XXX Add "Model-Specific Registers"
 
-        NUM_MISCREGS = MISCREG_SYSSEG_ATTR_BASE + NumSysSegments
+        NUM_MISCREGS
     };
 
     static inline MiscRegIndex
diff --git a/src/arch/x86/regfile.cc b/src/arch/x86/regfile.cc
index 96283cada..889f2f5cd 100644
--- a/src/arch/x86/regfile.cc
+++ b/src/arch/x86/regfile.cc
@@ -85,6 +85,7 @@
  * Authors: Gabe Black
  */
 
+#include "arch/x86/floatregs.hh"
 #include "arch/x86/regfile.hh"
 #include "base/trace.hh"
 #include "sim/serialize.hh"
@@ -218,6 +219,15 @@ int X86ISA::flattenIntIndex(ThreadContext * tc, int reg)
         return (reg & ~(1 << 6));
 }
 
+int X86ISA::flattenFloatIndex(ThreadContext * tc, int reg)
+{
+    if (reg > NUM_FLOATREGS) {
+        int top = tc->readMiscRegNoEffect(MISCREG_X87_TOP);
+        reg = FLOATREG_STACK(reg - NUM_FLOATREGS, top);
+    }
+    return reg;
+}
+
 void RegFile::serialize(std::ostream &os)
 {
     intRegFile.serialize(os);
diff --git a/src/arch/x86/regfile.hh b/src/arch/x86/regfile.hh
index d4425b04c..650181aca 100644
--- a/src/arch/x86/regfile.hh
+++ b/src/arch/x86/regfile.hh
@@ -149,6 +149,8 @@ namespace X86ISA
 
     int flattenIntIndex(ThreadContext * tc, int reg);
 
+    int flattenFloatIndex(ThreadContext * tc, int reg);
+
     void copyRegs(ThreadContext *src, ThreadContext *dest);
 
     void copyMiscRegs(ThreadContext *src, ThreadContext *dest);