diff --git a/lib/Target/X86/X86ISelPattern.cpp b/lib/Target/X86/X86ISelPattern.cpp
index 8aaf76b2bb2..5c4423057ad 100644
--- a/lib/Target/X86/X86ISelPattern.cpp
+++ b/lib/Target/X86/X86ISelPattern.cpp
@@ -184,8 +184,8 @@ namespace {
 
       if (X86ScalarSSE) {
         // Set up the FP register classes.
-        addRegisterClass(MVT::f32, X86::RXMMRegisterClass);
-        addRegisterClass(MVT::f64, X86::RXMMRegisterClass);
+        addRegisterClass(MVT::f32, X86::V4F4RegisterClass);
+        addRegisterClass(MVT::f64, X86::V2F8RegisterClass);
 
         // SSE has no load+extend ops
         setOperationAction(ISD::EXTLOAD,  MVT::f32, Expand);
@@ -4192,10 +4192,10 @@ void ISel::Select(SDOperand N) {
       case MVT::i8:  Opc = X86::MOV8rr; break;
       case MVT::i16: Opc = X86::MOV16rr; break;
       case MVT::i32: Opc = X86::MOV32rr; break;
-      case MVT::f32: Opc = X86::MOVAPSrr; break;
+      case MVT::f32: Opc = X86::MOVSSrr; break;
       case MVT::f64:
         if (X86ScalarSSE) {
-          Opc = X86::MOVAPDrr;
+          Opc = X86::MOVSDrr;
         } else {
           Opc = X86::FpMOV;
           ContainsFPCode = true;
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp
index 2fec723b25b..0f717c3c2d8 100644
--- a/lib/Target/X86/X86InstrInfo.cpp
+++ b/lib/Target/X86/X86InstrInfo.cpp
@@ -28,7 +28,7 @@ bool X86InstrInfo::isMoveInstr(const MachineInstr& MI,
                                unsigned& destReg) const {
   MachineOpCode oc = MI.getOpcode();
   if (oc == X86::MOV8rr || oc == X86::MOV16rr || oc == X86::MOV32rr ||
-      oc == X86::FpMOV  || oc == X86::MOVAPDrr || oc == X86::MOVAPSrr) {
+      oc == X86::FpMOV  || oc == X86::MOVSSrr || oc == X86::MOVSDrr) {
       assert(MI.getNumOperands() == 2 &&
              MI.getOperand(0).isRegister() &&
              MI.getOperand(1).isRegister() &&
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 7d89ae09e48..5844aa794fb 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -1408,142 +1408,134 @@ def MOVZX32rm16: I<0xB7, MRMSrcMem, (ops R32:$dst, i16mem:$src),
 // XMM Floating point support (requires SSE2)
 //===----------------------------------------------------------------------===//
 
-def MOVSSrm : I<0x10, MRMSrcMem, (ops RXMM:$dst, f32mem:$src),
+def MOVSSrr : I<0x10, MRMSrcReg, (ops V4F4:$dst, V4F4:$src),
                 "movss {$src, $dst|$dst, $src}">, XS;
-def MOVSSmr : I<0x11, MRMDestMem, (ops f32mem:$dst, RXMM:$src),
+def MOVSSrm : I<0x10, MRMSrcMem, (ops V4F4:$dst, f32mem:$src),
                 "movss {$src, $dst|$dst, $src}">, XS;
-def MOVSDrm : I<0x10, MRMSrcMem, (ops RXMM:$dst, f64mem:$src),
+def MOVSSmr : I<0x11, MRMDestMem, (ops f32mem:$dst, V4F4:$src),
+                "movss {$src, $dst|$dst, $src}">, XS;
+def MOVSDrr : I<0x10, MRMSrcReg, (ops V2F8:$dst, V2F8:$src),
                 "movsd {$src, $dst|$dst, $src}">, XD;
-def MOVSDmr : I<0x11, MRMDestMem, (ops f64mem:$dst, RXMM:$src),
+def MOVSDrm : I<0x10, MRMSrcMem, (ops V2F8:$dst, f64mem:$src),
+                "movsd {$src, $dst|$dst, $src}">, XD;
+def MOVSDmr : I<0x11, MRMDestMem, (ops f64mem:$dst, V2F8:$src),
                 "movsd {$src, $dst|$dst, $src}">, XD;
-def MOVAPSrr: I<0x28, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
-                "movaps {$src, $dst|$dst, $src}">, TB;
-def MOVAPSrm: I<0x28, MRMSrcMem, (ops RXMM:$dst, f32mem:$src),
-                "movaps {$src, $dst|$dst, $src}">, TB;
-def MOVAPSmr: I<0x29, MRMDestMem, (ops f32mem:$dst, RXMM:$src),
-                "movaps {$src, $dst|$dst, $src}">, TB;
-def MOVAPDrr: I<0x28, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
-                "movapd {$src, $dst|$dst, $src}">, TB, OpSize;
-def MOVAPDrm: I<0x28, MRMSrcMem, (ops RXMM:$dst, f64mem:$src),
-                "movapd {$src, $dst|$dst, $src}">, TB, OpSize;
-def MOVAPDmr: I<0x29, MRMDestMem, (ops f64mem:$dst, RXMM:$src),
-                "movapd {$src, $dst|$dst, $src}">, TB, OpSize;
 
-def CVTTSD2SIrr: I<0x2C, MRMSrcReg, (ops R32:$dst, RXMM:$src),
+def CVTTSD2SIrr: I<0x2C, MRMSrcReg, (ops R32:$dst, V2F8:$src),
                 "cvttsd2si {$src, $dst|$dst, $src}">, XD;
 def CVTTSD2SIrm: I<0x2C, MRMSrcMem, (ops R32:$dst, f64mem:$src),
                 "cvttsd2si {$src, $dst|$dst, $src}">, XD;
-def CVTTSS2SIrr: I<0x2C, MRMSrcReg, (ops R32:$dst, RXMM:$src),
+def CVTTSS2SIrr: I<0x2C, MRMSrcReg, (ops R32:$dst, V4F4:$src),
                 "cvttss2si {$src, $dst|$dst, $src}">, XS;
 def CVTTSS2SIrm: I<0x2C, MRMSrcMem, (ops R32:$dst, f32mem:$src),
                 "cvttss2si {$src, $dst|$dst, $src}">, XS;
-def CVTSD2SSrr: I<0x5A, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
+def CVTSD2SSrr: I<0x5A, MRMSrcReg, (ops V4F4:$dst, V2F8:$src),
                 "cvtsd2ss {$src, $dst|$dst, $src}">, XS;
-def CVTSD2SSrm: I<0x5A, MRMSrcMem, (ops RXMM:$dst, f64mem:$src), 
+def CVTSD2SSrm: I<0x5A, MRMSrcMem, (ops V4F4:$dst, f64mem:$src), 
                 "cvtsd2ss {$src, $dst|$dst, $src}">, XS;
-def CVTSS2SDrr: I<0x5A, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
+def CVTSS2SDrr: I<0x5A, MRMSrcReg, (ops V2F8:$dst, V4F4:$src),
                 "cvtss2sd {$src, $dst|$dst, $src}">, XD;
-def CVTSS2SDrm: I<0x5A, MRMSrcMem, (ops RXMM:$dst, f32mem:$src),
+def CVTSS2SDrm: I<0x5A, MRMSrcMem, (ops V2F8:$dst, f32mem:$src),
                 "cvtss2sd {$src, $dst|$dst, $src}">, XD;
-def CVTSI2SSrr: I<0x2A, MRMSrcReg, (ops R32:$dst, RXMM:$src),
+def CVTSI2SSrr: I<0x2A, MRMSrcReg, (ops V4F4:$dst, R32:$src),
                 "cvtsi2ss {$src, $dst|$dst, $src}">, XS;
-def CVTSI2SSrm: I<0x2A, MRMSrcMem, (ops R32:$dst, f32mem:$src),
+def CVTSI2SSrm: I<0x2A, MRMSrcMem, (ops V4F4:$dst, i32mem:$src),
                 "cvtsi2ss {$src, $dst|$dst, $src}">, XS;
-def CVTSI2SDrr: I<0x2A, MRMSrcReg, (ops R32:$dst, RXMM:$src),
+def CVTSI2SDrr: I<0x2A, MRMSrcReg, (ops V2F8:$dst, R32:$src),
                 "cvtsi2sd {$src, $dst|$dst, $src}">, XD;
-def CVTSI2SDrm: I<0x2A, MRMSrcMem, (ops R32:$dst, f64mem:$src),
+def CVTSI2SDrm: I<0x2A, MRMSrcMem, (ops V2F8:$dst, i32mem:$src),
                 "cvtsi2sd {$src, $dst|$dst, $src}">, XD;
 
-def SQRTSSrm : I<0x51, MRMSrcMem, (ops RXMM:$dst, f32mem:$src),
+def SQRTSSrm : I<0x51, MRMSrcMem, (ops V4F4:$dst, f32mem:$src),
                 "subss {$src, $dst|$dst, $src}">, XS;
-def SQRTSSrr : I<0x51, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
+def SQRTSSrr : I<0x51, MRMSrcReg, (ops V4F4:$dst, V4F4:$src),
                 "subss {$src, $dst|$dst, $src}">, XS;
-def SQRTSDrm : I<0x51, MRMSrcMem, (ops RXMM:$dst, f64mem:$src),
+def SQRTSDrm : I<0x51, MRMSrcMem, (ops V2F8:$dst, f64mem:$src),
                 "subsd {$src, $dst|$dst, $src}">, XD;
-def SQRTSDrr : I<0x51, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
+def SQRTSDrr : I<0x51, MRMSrcReg, (ops V2F8:$dst, V2F8:$src),
                 "subsd {$src, $dst|$dst, $src}">, XD;
 
-def UCOMISDrr: I<0x2E, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
+def UCOMISDrr: I<0x2E, MRMSrcReg, (ops V2F8:$dst, V2F8:$src),
                 "ucomisd {$src, $dst|$dst, $src}">, TB, OpSize;
-def UCOMISDrm: I<0x2E, MRMSrcMem, (ops RXMM:$dst, f64mem:$src),
+def UCOMISDrm: I<0x2E, MRMSrcMem, (ops V2F8:$dst, f64mem:$src),
                 "ucomisd {$src, $dst|$dst, $src}">, TB, OpSize;
-def UCOMISSrr: I<0x2E, MRMSrcReg, (ops RXMM:$dst, RXMM:$src),
+def UCOMISSrr: I<0x2E, MRMSrcReg, (ops V4F4:$dst, V4F4:$src),
                 "ucomiss {$src, $dst|$dst, $src}">, TB;
-def UCOMISSrm: I<0x2E, MRMSrcMem, (ops RXMM:$dst, f32mem:$src),
+def UCOMISSrm: I<0x2E, MRMSrcMem, (ops V4F4:$dst, f32mem:$src),
                 "ucomiss {$src, $dst|$dst, $src}">, TB;
 
 // Pseudo-instructions that map to fld0 to xorps/xorpd for sse.
 // FIXME: remove when we can teach regalloc that xor reg, reg is ok.
-def FLD0SS : I<0x57, MRMSrcReg, (ops RXMM:$dst),
+def FLD0SS : I<0x57, MRMSrcReg, (ops V4F4:$dst),
                 "xorps $dst, $dst">, TB;
-def FLD0SD : I<0x57, MRMSrcReg, (ops RXMM:$dst),
+def FLD0SD : I<0x57, MRMSrcReg, (ops V2F8:$dst),
                 "xorpd $dst, $dst">, TB, OpSize;
 
 let isTwoAddress = 1 in {
 let isCommutable = 1 in {
-def ADDSSrr : I<0x58, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ADDSSrr : I<0x58, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "addss {$src, $dst|$dst, $src}">, XS;
-def ADDSDrr : I<0x58, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ADDSDrr : I<0x58, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "addsd {$src, $dst|$dst, $src}">, XD;
-def ANDPSrr : I<0x54, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ANDPSrr : I<0x54, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "andps {$src, $dst|$dst, $src}">, TB;
-def ANDPDrr : I<0x54, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ANDPDrr : I<0x54, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "andpd {$src, $dst|$dst, $src}">, TB, OpSize;
-def MULSSrr : I<0x59, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def MULSSrr : I<0x59, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "mulss {$src, $dst|$dst, $src}">, XS;
-def MULSDrr : I<0x59, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def MULSDrr : I<0x59, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "mulsd {$src, $dst|$dst, $src}">, XD;
-def ORPSrr : I<0x56, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ORPSrr : I<0x56, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "orps {$src, $dst|$dst, $src}">, TB;
-def ORPDrr : I<0x56, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ORPDrr : I<0x56, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "orpd {$src, $dst|$dst, $src}">, TB, OpSize;
-def XORPSrr : I<0x57, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def XORPSrr : I<0x57, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "xorps {$src, $dst|$dst, $src}">, TB;
-def XORPDrr : I<0x57, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def XORPDrr : I<0x57, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "xorpd {$src, $dst|$dst, $src}">, TB, OpSize;
 }
-def ANDNPSrr : I<0x55, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ANDNPSrr : I<0x55, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "andnps {$src, $dst|$dst, $src}">, TB;
-def ANDNPDrr : I<0x55, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def ANDNPDrr : I<0x55, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "andnpd {$src, $dst|$dst, $src}">, TB, OpSize;
-def ADDSSrm : I<0x58, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f32mem:$src),
+def ADDSSrm : I<0x58, MRMSrcMem, (ops V4F4:$dst, V4F4:$src1, f32mem:$src),
                 "addss {$src, $dst|$dst, $src}">, XS;
-def ADDSDrm : I<0x58, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f64mem:$src),
+def ADDSDrm : I<0x58, MRMSrcMem, (ops V2F8:$dst, V2F8:$src1, f64mem:$src),
                 "addsd {$src, $dst|$dst, $src}">, XD;
-def MULSSrm : I<0x59, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f32mem:$src),
+def MULSSrm : I<0x59, MRMSrcMem, (ops V4F4:$dst, V4F4:$src1, f32mem:$src),
                 "mulss {$src, $dst|$dst, $src}">, XS;
-def MULSDrm : I<0x59, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f64mem:$src),
+def MULSDrm : I<0x59, MRMSrcMem, (ops V2F8:$dst, V2F8:$src1, f64mem:$src),
                 "mulsd {$src, $dst|$dst, $src}">, XD;
 
-def DIVSSrm : I<0x5E, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f32mem:$src),
+def DIVSSrm : I<0x5E, MRMSrcMem, (ops V4F4:$dst, V4F4:$src1, f32mem:$src),
                 "divss {$src, $dst|$dst, $src}">, XS;
-def DIVSSrr : I<0x5E, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def DIVSSrr : I<0x5E, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "divss {$src, $dst|$dst, $src}">, XS;
-def DIVSDrm : I<0x5E, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f64mem:$src),
+def DIVSDrm : I<0x5E, MRMSrcMem, (ops V2F8:$dst, V2F8:$src1, f64mem:$src),
                 "divsd {$src, $dst|$dst, $src}">, XD;
-def DIVSDrr : I<0x5E, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def DIVSDrr : I<0x5E, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "divsd {$src, $dst|$dst, $src}">, XD;
 
-def SUBSSrm : I<0x5C, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f32mem:$src),
+def SUBSSrm : I<0x5C, MRMSrcMem, (ops V4F4:$dst, V4F4:$src1, f32mem:$src),
                 "subss {$src, $dst|$dst, $src}">, XS;
-def SUBSSrr : I<0x5C, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def SUBSSrr : I<0x5C, MRMSrcReg, (ops V4F4:$dst, V4F4:$src1, V4F4:$src),
                 "subss {$src, $dst|$dst, $src}">, XS;
-def SUBSDrm : I<0x5C, MRMSrcMem, (ops RXMM:$dst, RXMM:$src1, f64mem:$src),
+def SUBSDrm : I<0x5C, MRMSrcMem, (ops V2F8:$dst, V2F8:$src1, f64mem:$src),
                 "subsd {$src, $dst|$dst, $src}">, XD;
-def SUBSDrr : I<0x5C, MRMSrcReg, (ops RXMM:$dst, RXMM:$src1, RXMM:$src),
+def SUBSDrr : I<0x5C, MRMSrcReg, (ops V2F8:$dst, V2F8:$src1, V2F8:$src),
                 "subsd {$src, $dst|$dst, $src}">, XD;
 
 def CMPSSrr : I<0xC2, MRMSrcReg, 
-                (ops RXMM:$dst, RXMM:$src1, RXMM:$src, SSECC:$cc),
+                (ops V4F4:$dst, V4F4:$src1, V4F4:$src, SSECC:$cc),
                 "cmp${cc}ss {$src, $dst|$dst, $src}">, XS;
 def CMPSSrm : I<0xC2, MRMSrcMem, 
-                (ops RXMM:$dst, RXMM:$src1, f32mem:$src, SSECC:$cc),
+                (ops V4F4:$dst, V4F4:$src1, f32mem:$src, SSECC:$cc),
                 "cmp${cc}ss {$src, $dst|$dst, $src}">, XS;
 def CMPSDrr : I<0xC2, MRMSrcReg, 
-                (ops RXMM:$dst, RXMM:$src1, RXMM:$src, SSECC:$cc),
+                (ops V2F8:$dst, V2F8:$src1, V2F8:$src, SSECC:$cc),
                 "cmp${cc}sd {$src, $dst|$dst, $src}">, XD;
 def CMPSDrm : I<0xC2, MRMSrcMem, 
-                (ops RXMM:$dst, RXMM:$src1, f64mem:$src, SSECC:$cc),
+                (ops V2F8:$dst, V2F8:$src1, f64mem:$src, SSECC:$cc),
                 "cmp${cc}sd {$src, $dst|$dst, $src}">, XD;
 }
 
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 12761078964..a0e0aca16c2 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -57,7 +57,9 @@ void X86RegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
     Opc = X86::MOV16mr;
   } else if (RC == &X86::RFPRegClass || RC == &X86::RSTRegClass) {
     Opc = X86::FST64m;
-  } else if (RC == &X86::RXMMRegClass) {
+  } else if (RC == &X86::V4F4RegClass) {
+    Opc = X86::MOVSSmr;
+  } else if (RC == &X86::V2F8RegClass) {
     Opc = X86::MOVSDmr;
   } else {
     assert(0 && "Unknown regclass");
@@ -79,7 +81,9 @@ void X86RegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
     Opc = X86::MOV16rm;
   } else if (RC == &X86::RFPRegClass || RC == &X86::RSTRegClass) {
     Opc = X86::FLD64m;
-  } else if (RC == &X86::RXMMRegClass) {
+  } else if (RC == &X86::V4F4RegClass) {
+    Opc = X86::MOVSSrm;
+  } else if (RC == &X86::V2F8RegClass) {
     Opc = X86::MOVSDrm;
   } else {
     assert(0 && "Unknown regclass");
@@ -101,8 +105,10 @@ void X86RegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
     Opc = X86::MOV16rr;
   } else if (RC == &X86::RFPRegClass || RC == &X86::RSTRegClass) {
     Opc = X86::FpMOV;
-  } else if (RC == &X86::RXMMRegClass) {
-    Opc = X86::MOVAPDrr;
+  } else if (RC == &X86::V4F4RegClass) {
+    Opc = X86::MOVSSrr;
+  } else if (RC == &X86::V2F8RegClass) {
+    Opc = X86::MOVSDrr;
   } else {
     assert(0 && "Unknown regclass");
     abort();
@@ -119,7 +125,7 @@ unsigned X86RegisterInfo::isLoadFromStackSlot(MachineInstr *MI,
   case X86::MOV32rm:
   case X86::FLD64m:
   case X86::FLD80m:
-  case X86::MOVAPDrm:
+  case X86::MOVSSrm:
   case X86::MOVSDrm:
     if (MI->getOperand(1).isFrameIndex() && MI->getOperand(2).isImmediate() &&
         MI->getOperand(3).isRegister() && MI->getOperand(4).isImmediate() &&
diff --git a/lib/Target/X86/X86RegisterInfo.td b/lib/Target/X86/X86RegisterInfo.td
index 63bc7bd09d1..64571525cd4 100644
--- a/lib/Target/X86/X86RegisterInfo.td
+++ b/lib/Target/X86/X86RegisterInfo.td
@@ -104,10 +104,11 @@ def R32 : RegisterClass<"X86", i32, 32, [EAX, ECX, EDX, ESI, EDI, EBX, EBP, ESP]
   }];
 }
 
-// FIXME: These registers can contain both integer and fp values.  We should
-// figure out the right way to deal with that.  For now, since they'll be used
-// for scalar FP, they are being declared f64
-def RXMM : RegisterClass<"X86", f64, 32,
+// V4F4, the 4 x f32 class, and V2F8, the 2 x f64 class, which we will use for
+// Scalar SSE2 floating point support.
+def V4F4 : RegisterClass<"X86", f32, 32,
+                         [XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7]>;
+def V2F8 : RegisterClass<"X86", f64, 64,
                          [XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7]>;
 
 // FIXME: This sets up the floating point register files as though they are f64