diff --git a/lib/Target/X86/X86RegisterClasses.cpp b/lib/Target/X86/X86RegisterClasses.cpp
index c9d0aa46f2c..1efec5d4833 100644
--- a/lib/Target/X86/X86RegisterClasses.cpp
+++ b/lib/Target/X86/X86RegisterClasses.cpp
@@ -9,6 +9,9 @@
 #include "llvm/Type.h"
 #include "X86.h"
 
+//===----------------------------------------------------------------------===//
+//   8 Bit Integer Registers
+//
 namespace {
   const unsigned ByteRegClassRegs[] = {
 #define R8(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET) X86::ENUM,
@@ -18,8 +21,8 @@ namespace {
   TargetRegisterClass X86ByteRegisterClassInstance(1, ByteRegClassRegs,
  ByteRegClassRegs+sizeof(ByteRegClassRegs)/sizeof(ByteRegClassRegs[0]));
 
-//
-//
+//===----------------------------------------------------------------------===//
+//   16 Bit Integer Registers
 //
   const unsigned ShortRegClassRegs[] = {
 #define R16(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET) X86::ENUM,
@@ -29,10 +32,9 @@ namespace {
   TargetRegisterClass X86ShortRegisterClassInstance(2, ShortRegClassRegs,
       ShortRegClassRegs+sizeof(ShortRegClassRegs)/sizeof(ShortRegClassRegs[0]));
 
+//===----------------------------------------------------------------------===//
+//   32 Bit Integer Registers
 //
-//
-//
-
   const unsigned IntRegClassRegs[] = {
 #define R32(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET) X86::ENUM,
 #include "X86RegisterInfo.def"
@@ -41,10 +43,25 @@ namespace {
   TargetRegisterClass X86IntRegisterClassInstance(4, IntRegClassRegs,
       IntRegClassRegs+sizeof(IntRegClassRegs)/sizeof(IntRegClassRegs[0]));
 
+//===----------------------------------------------------------------------===//
+//   Pseudo Floating Point Registers
+//
+  const unsigned PFPRegClassRegs[] = {
+#define PFP(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET) X86::ENUM,
+#include "X86RegisterInfo.def"
+  };
+
+  TargetRegisterClass X86FPRegisterClassInstance(10, PFPRegClassRegs,
+      PFPRegClassRegs+sizeof(PFPRegClassRegs)/sizeof(PFPRegClassRegs[0]));
+
+//===----------------------------------------------------------------------===//
+// Register class array...
+//
   const TargetRegisterClass * const X86RegClasses[] = {
     &X86ByteRegisterClassInstance,
     &X86ShortRegisterClassInstance,
-    &X86IntRegisterClassInstance
+    &X86IntRegisterClassInstance,
+    &X86FPRegisterClassInstance,
   };
 }
 
@@ -72,26 +89,23 @@ X86RegisterInfo::X86RegisterInfo()
 
 
 
-const TargetRegisterClass* X86RegisterInfo::getRegClassForType(const Type* Ty)
-  const {
+const TargetRegisterClass*
+X86RegisterInfo::getRegClassForType(const Type* Ty) const {
   switch (Ty->getPrimitiveID()) {
+  default:                assert(0 && "Invalid type to getClass!");
   case Type::BoolTyID:
   case Type::SByteTyID:
   case Type::UByteTyID:   return &X86ByteRegisterClassInstance;
   case Type::ShortTyID:
   case Type::UShortTyID:  return &X86ShortRegisterClassInstance;
-  case Type::LongTyID:    // None of these are handled yet!
-  case Type::ULongTyID:  // FIXME: Treat these like ints, this is bogus!
+  case Type::LongTyID:    // FIXME: Longs are not handled yet!
+  case Type::ULongTyID:   // FIXME: Treat these like ints, this is bogus!
     
   case Type::IntTyID:
   case Type::UIntTyID:
   case Type::PointerTyID: return &X86IntRegisterClassInstance;
     
   case Type::FloatTyID:
-  case Type::DoubleTyID:
-    
-  default:
-    assert(0 && "Invalid type to getClass!");
-    return 0;  // not reached
+  case Type::DoubleTyID: return &X86FPRegisterClassInstance;
   }
 }
diff --git a/lib/Target/X86/X86RegisterInfo.def b/lib/Target/X86/X86RegisterInfo.def
index d8e7fd23e72..b581b9ae12b 100644
--- a/lib/Target/X86/X86RegisterInfo.def
+++ b/lib/Target/X86/X86RegisterInfo.def
@@ -27,6 +27,18 @@
    R(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET)
 #endif
 
+// Pseudo Floating Point registers
+#ifndef PFP
+#define PFP(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET) \
+   R(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET)
+#endif
+
+// Floating Point Stack registers
+#ifndef FPS
+#define FPS(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET) \
+   R(ENUM, NAME, FLAGS, TSFLAGS, ALIAS_SET)
+#endif
+
 // Arguments passed into the R macros
 //  #1: Enum Name - This ends up being a symbol in the X86 namespace
 //  #2: Register name - The name of the register as used by the gnu assembler
@@ -69,14 +81,33 @@ R16( SI, "SI" , MRF::INT16, 0, A_SI)
 R16( DI, "DI" , MRF::INT16, 0, A_DI)
 
 // 8 bit registers aliased with registers above as well
-  R8 ( AL, "AL" , MRF::INT8 , 0, A_AL)
-  R8 ( CL, "CL" , MRF::INT8 , 0, A_CL)
-  R8 ( DL, "DL" , MRF::INT8 , 0, A_DL)
-  R8 ( BL, "BL" , MRF::INT8 , 0, A_BL)
-  R8 ( AH, "AH" , MRF::INT8 , 0, A_AH)
-  R8 ( CH, "CH" , MRF::INT8 , 0, A_CH)
-  R8 ( DH, "DH" , MRF::INT8 , 0, A_DH)
-  R8 ( BH, "BH" , MRF::INT8 , 0, A_BH)
+R8 ( AL, "AL" , MRF::INT8 , 0, A_AL)
+R8 ( CL, "CL" , MRF::INT8 , 0, A_CL)
+R8 ( DL, "DL" , MRF::INT8 , 0, A_DL)
+R8 ( BL, "BL" , MRF::INT8 , 0, A_BL)
+R8 ( AH, "AH" , MRF::INT8 , 0, A_AH)
+R8 ( CH, "CH" , MRF::INT8 , 0, A_CH)
+R8 ( DH, "DH" , MRF::INT8 , 0, A_DH)
+R8 ( BH, "BH" , MRF::INT8 , 0, A_BH)
+
+// Pseudo Floating Point Registers
+PFP(FP0, "fp0", MRF::FP80 , 0, 0 /*noalias*/)
+PFP(FP1, "fp1", MRF::FP80 , 0, 0 /*noalias*/)
+PFP(FP2, "fp2", MRF::FP80 , 0, 0 /*noalias*/)
+PFP(FP3, "fp3", MRF::FP80 , 0, 0 /*noalias*/)
+PFP(FP4, "fp4", MRF::FP80 , 0, 0 /*noalias*/)
+PFP(FP5, "fp5", MRF::FP80 , 0, 0 /*noalias*/)
+PFP(FP6, "fp6", MRF::FP80 , 0, 0 /*noalias*/)
+
+// Floating point stack registers
+FPS(ST0, "ST(0)", MRF::FP80, 0, 0)
+FPS(ST1, "ST(1)", MRF::FP80, 0, 0)
+FPS(ST2, "ST(2)", MRF::FP80, 0, 0)
+FPS(ST3, "ST(3)", MRF::FP80, 0, 0)
+FPS(ST4, "ST(4)", MRF::FP80, 0, 0)
+FPS(ST5, "ST(5)", MRF::FP80, 0, 0)
+FPS(ST6, "ST(6)", MRF::FP80, 0, 0)
+FPS(ST7, "ST(7)", MRF::FP80, 0, 0)
 
 // Flags, Segment registers, etc...
 
@@ -126,3 +157,5 @@ ALIASLIST(A_BH      , X86::EBX, X86::BX, 0)
 #undef R8
 #undef R16
 #undef R32
+#undef PFP
+#undef FPS