Index: llvm/trunk/lib/Target/Mips/Mips.td
===================================================================
--- llvm/trunk/lib/Target/Mips/Mips.td
+++ llvm/trunk/lib/Target/Mips/Mips.td
@@ -61,6 +61,8 @@
                                 "General Purpose Registers are 64-bit wide.">;
 def FeatureFP64Bit     : SubtargetFeature<"fp64", "IsFP64bit", "true",
                                 "Support 64-bit FP registers.">;
+def FeatureFPXX        : SubtargetFeature<"fpxx", "IsFPXX", "true",
+                                "Support for FPXX.">;
 def FeatureNaN2008     : SubtargetFeature<"nan2008", "IsNaN2008bit", "true",
                                 "IEEE 754-2008 NaN encoding.">;
 def FeatureSingleFloat : SubtargetFeature<"single-float", "IsSingleFloat",
Index: llvm/trunk/lib/Target/Mips/MipsCallingConv.td
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsCallingConv.td
+++ llvm/trunk/lib/Target/Mips/MipsCallingConv.td
@@ -239,6 +239,11 @@
 def CSR_SingleFloatOnly : CalleeSavedRegs<(add (sequence "F%u", 31, 20), RA, FP,
                                                (sequence "S%u", 7, 0))>;
 
+def CSR_O32_FPXX : CalleeSavedRegs<(add (sequence "D%u", 15, 10), RA, FP,
+                                        (sequence "S%u", 7, 0))> {
+  let OtherPreserved = (add (decimate (sequence "F%u", 30, 20), 2));
+}
+
 def CSR_O32 : CalleeSavedRegs<(add (sequence "D%u", 15, 10), RA, FP,
                                    (sequence "S%u", 7, 0))>;
 
Index: llvm/trunk/lib/Target/Mips/MipsRegisterInfo.cpp
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsRegisterInfo.cpp
+++ llvm/trunk/lib/Target/Mips/MipsRegisterInfo.cpp
@@ -93,6 +93,9 @@
   if (Subtarget.isFP64bit())
     return CSR_O32_FP64_SaveList;
 
+  if (Subtarget.isFPXX())
+    return CSR_O32_FPXX_SaveList;
+
   return CSR_O32_SaveList;
 }
 
@@ -110,6 +113,9 @@
   if (Subtarget.isFP64bit())
     return CSR_O32_FP64_RegMask;
 
+  if (Subtarget.isFPXX())
+    return CSR_O32_FPXX_RegMask;
+
   return CSR_O32_RegMask;
 }
 
Index: llvm/trunk/lib/Target/Mips/MipsSubtarget.h
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsSubtarget.h
+++ llvm/trunk/lib/Target/Mips/MipsSubtarget.h
@@ -62,6 +62,9 @@
   // floating point registers instead of only using even ones.
   bool IsSingleFloat;
 
+  // IsFPXX - MIPS O32 modeless ABI.
+  bool IsFPXX;
+
   // IsFP64bit - The target processor has 64-bit floating point registers.
   bool IsFP64bit;
 
@@ -206,6 +209,7 @@
   bool hasCnMips() const { return HasCnMips; }
 
   bool isLittle() const { return IsLittle; }
+  bool isFPXX() const { return IsFPXX; }
   bool isFP64bit() const { return IsFP64bit; }
   bool useOddSPReg() const { return UseOddSPReg; }
   bool isNaN2008() const { return IsNaN2008bit; }
Index: llvm/trunk/lib/Target/Mips/MipsSubtarget.cpp
===================================================================
--- llvm/trunk/lib/Target/Mips/MipsSubtarget.cpp
+++ llvm/trunk/lib/Target/Mips/MipsSubtarget.cpp
@@ -107,7 +107,7 @@
                              Reloc::Model _RM, MipsTargetMachine *_TM)
     : MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(Mips32),
       MipsABI(UnknownABI), IsLittle(little), IsSingleFloat(false),
-      IsFP64bit(false), UseOddSPReg(true), IsNaN2008bit(false),
+      IsFPXX(false), IsFP64bit(false), UseOddSPReg(true), IsNaN2008bit(false),
       IsGP64bit(false), HasVFPU(false), HasCnMips(false), IsLinux(true),
       HasMips3_32(false), HasMips3_32r2(false), HasMips4_32(false),
       HasMips4_32r2(false), HasMips5_32r2(false), InMips16Mode(false),
Index: llvm/trunk/test/CodeGen/Mips/cconv/callee-saved-fpxx.ll
===================================================================
--- llvm/trunk/test/CodeGen/Mips/cconv/callee-saved-fpxx.ll
+++ llvm/trunk/test/CodeGen/Mips/cconv/callee-saved-fpxx.ll
@@ -0,0 +1,58 @@
+; RUN: llc -march=mips -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX %s
+; RUN: llc -march=mipsel -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX %s
+; RUN: llc -march=mips -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX-INV %s
+; RUN: llc -march=mipsel -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX-INV %s
+
+; RUN-TODO: llc -march=mips64 -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX %s
+; RUN-TODO: llc -march=mips64el -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX %s
+; RUN-TODO: llc -march=mips64 -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX-INV --check-prefix=O32-FPXX-INV %s
+; RUN-TODO: llc -march=mips64el -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=ALL --check-prefix=O32-FPXX-INV --check-prefix=O32-FPXX-INV %s
+
+define void @fpu_clobber() nounwind {
+entry:
+    call void asm "# Clobber", "~{$f0},~{$f1},~{$f2},~{$f3},~{$f4},~{$f5},~{$f6},~{$f7},~{$f8},~{$f9},~{$f10},~{$f11},~{$f12},~{$f13},~{$f14},~{$f15},~{$f16},~{$f17},~{$f18},~{$f19},~{$f20},~{$f21},~{$f22},~{$f23},~{$f24},~{$f25},~{$f26},~{$f27},~{$f28},~{$f29},~{$f30},~{$f31}"()
+    ret void
+}
+
+; O32-FPXX-LABEL: fpu_clobber:
+; O32-FPXX-INV-NOT:   sdc1 $f0,
+; O32-FPXX-INV-NOT:   sdc1 $f1,
+; O32-FPXX-INV-NOT:   sdc1 $f2,
+; O32-FPXX-INV-NOT:   sdc1 $f3,
+; O32-FPXX-INV-NOT:   sdc1 $f4,
+; O32-FPXX-INV-NOT:   sdc1 $f5,
+; O32-FPXX-INV-NOT:   sdc1 $f6,
+; O32-FPXX-INV-NOT:   sdc1 $f7,
+; O32-FPXX-INV-NOT:   sdc1 $f8,
+; O32-FPXX-INV-NOT:   sdc1 $f9,
+; O32-FPXX-INV-NOT:   sdc1 $f10,
+; O32-FPXX-INV-NOT:   sdc1 $f11,
+; O32-FPXX-INV-NOT:   sdc1 $f12,
+; O32-FPXX-INV-NOT:   sdc1 $f13,
+; O32-FPXX-INV-NOT:   sdc1 $f14,
+; O32-FPXX-INV-NOT:   sdc1 $f15,
+; O32-FPXX-INV-NOT:   sdc1 $f16,
+; O32-FPXX-INV-NOT:   sdc1 $f17,
+; O32-FPXX-INV-NOT:   sdc1 $f18,
+; O32-FPXX-INV-NOT:   sdc1 $f19,
+; O32-FPXX-INV-NOT:   sdc1 $f21,
+; O32-FPXX-INV-NOT:   sdc1 $f23,
+; O32-FPXX-INV-NOT:   sdc1 $f25,
+; O32-FPXX-INV-NOT:   sdc1 $f27,
+; O32-FPXX-INV-NOT:   sdc1 $f29,
+; O32-FPXX-INV-NOT:   sdc1 $f31,
+
+; O32-FPXX:           addiu $sp, $sp, -48
+; O32-FPXX-DAG:       sdc1 [[F20:\$f20]], [[OFF20:[0-9]+]]($sp)
+; O32-FPXX-DAG:       sdc1 [[F22:\$f22]], [[OFF22:[0-9]+]]($sp)
+; O32-FPXX-DAG:       sdc1 [[F24:\$f24]], [[OFF24:[0-9]+]]($sp)
+; O32-FPXX-DAG:       sdc1 [[F26:\$f26]], [[OFF26:[0-9]+]]($sp)
+; O32-FPXX-DAG:       sdc1 [[F28:\$f28]], [[OFF28:[0-9]+]]($sp)
+; O32-FPXX-DAG:       sdc1 [[F30:\$f30]], [[OFF30:[0-9]+]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F20]], [[OFF20]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F22]], [[OFF22]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F24]], [[OFF24]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F26]], [[OFF26]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F28]], [[OFF28]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F30]], [[OFF30]]($sp)
+; O32-FPXX:           addiu $sp, $sp, 48
Index: llvm/trunk/test/CodeGen/Mips/cconv/callee-saved-fpxx1.ll
===================================================================
--- llvm/trunk/test/CodeGen/Mips/cconv/callee-saved-fpxx1.ll
+++ llvm/trunk/test/CodeGen/Mips/cconv/callee-saved-fpxx1.ll
@@ -0,0 +1,24 @@
+; RUN: llc -march=mips -mattr=+o32,+fp64 < %s | FileCheck --check-prefix=O32-FP64-INV %s
+; RUN: llc -march=mipsel -mattr=+o32,+fp64 < %s | FileCheck --check-prefix=O32-FP64-INV %s
+
+; RUN: llc -march=mips -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=O32-FPXX %s
+; RUN: llc -march=mipsel -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=O32-FPXX %s
+
+; RUN-TODO: llc -march=mips64 -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=O32-FPXX %s
+; RUN-TODO: llc -march=mips64el -mattr=+o32,+fpxx < %s | FileCheck --check-prefix=O32-FPXX %s
+
+define void @fpu_clobber() nounwind {
+entry:
+    call void asm "# Clobber", "~{$f21}"()
+    ret void
+}
+
+; O32-FPXX-LABEL: fpu_clobber:
+
+; O32-FPXX:           addiu $sp, $sp, -8
+
+; O32-FP64-INV-NOT:   sdc1 $f20,
+; O32-FPXX-DAG:       sdc1 [[F20:\$f20]], [[OFF20:[0-9]+]]($sp)
+; O32-FPXX-DAG:       ldc1 [[F20]], [[OFF20]]($sp)
+
+; O32-FPXX:           addiu $sp, $sp, 8