Index: cfe/trunk/lib/CodeGen/TargetInfo.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/TargetInfo.cpp
+++ cfe/trunk/lib/CodeGen/TargetInfo.cpp
@@ -3413,8 +3413,10 @@
 namespace {
 /// PPC32_SVR4_ABIInfo - The 32-bit PowerPC ELF (SVR4) ABI information.
 class PPC32_SVR4_ABIInfo : public DefaultABIInfo {
+bool IsSoftFloatABI;
 public:
-  PPC32_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT) : DefaultABIInfo(CGT) {}
+  PPC32_SVR4_ABIInfo(CodeGen::CodeGenTypes &CGT, bool SoftFloatABI)
+      : DefaultABIInfo(CGT), IsSoftFloatABI(SoftFloatABI) {}
 
   Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
                     QualType Ty) const override;
@@ -3422,8 +3424,8 @@
 
 class PPC32TargetCodeGenInfo : public TargetCodeGenInfo {
 public:
-  PPC32TargetCodeGenInfo(CodeGenTypes &CGT)
-      : TargetCodeGenInfo(new PPC32_SVR4_ABIInfo(CGT)) {}
+  PPC32TargetCodeGenInfo(CodeGenTypes &CGT, bool SoftFloatABI)
+      : TargetCodeGenInfo(new PPC32_SVR4_ABIInfo(CGT, SoftFloatABI)) {}
 
   int getDwarfEHStackPointer(CodeGen::CodeGenModule &M) const override {
     // This is recovered from gcc output.
@@ -3455,6 +3457,7 @@
   bool isI64 = Ty->isIntegerType() && getContext().getTypeSize(Ty) == 64;
   bool isInt =
       Ty->isIntegerType() || Ty->isPointerType() || Ty->isAggregateType();
+  bool isF64 = Ty->isFloatingType() && getContext().getTypeSize(Ty) == 64;
 
   // All aggregates are passed indirectly?  That doesn't seem consistent
   // with the argument-lowering code.
@@ -3464,7 +3467,7 @@
 
   // The calling convention either uses 1-2 GPRs or 1 FPR.
   Address NumRegsAddr = Address::invalid();
-  if (isInt) {
+  if (isInt || IsSoftFloatABI) {
     NumRegsAddr = Builder.CreateStructGEP(VAList, 0, CharUnits::Zero(), "gpr");
   } else {
     NumRegsAddr = Builder.CreateStructGEP(VAList, 1, CharUnits::One(), "fpr");
@@ -3473,7 +3476,7 @@
   llvm::Value *NumRegs = Builder.CreateLoad(NumRegsAddr, "numUsedRegs");
 
   // "Align" the register count when TY is i64.
-  if (isI64) {
+  if (isI64 || (isF64 && IsSoftFloatABI)) {
     NumRegs = Builder.CreateAdd(NumRegs, Builder.getInt8(1));
     NumRegs = Builder.CreateAnd(NumRegs, Builder.getInt8((uint8_t) ~1U));
   }
@@ -3502,14 +3505,14 @@
     assert(RegAddr.getElementType() == CGF.Int8Ty);
 
     // Floating-point registers start after the general-purpose registers.
-    if (!isInt) {
+    if (!(isInt || IsSoftFloatABI)) {
       RegAddr = Builder.CreateConstInBoundsByteGEP(RegAddr,
                                                    CharUnits::fromQuantity(32));
     }
 
     // Get the address of the saved value by scaling the number of
     // registers we've used by the number of 
-    CharUnits RegSize = CharUnits::fromQuantity(isInt ? 4 : 8);
+    CharUnits RegSize = CharUnits::fromQuantity((isInt || IsSoftFloatABI) ? 4 : 8);
     llvm::Value *RegOffset =
       Builder.CreateMul(NumRegs, Builder.getInt8(RegSize.getQuantity()));
     RegAddr = Address(Builder.CreateInBoundsGEP(CGF.Int8Ty,
@@ -3518,7 +3521,9 @@
     RegAddr = Builder.CreateElementBitCast(RegAddr, DirectTy);
 
     // Increase the used-register count.
-    NumRegs = Builder.CreateAdd(NumRegs, Builder.getInt8(isI64 ? 2 : 1));
+    NumRegs =
+      Builder.CreateAdd(NumRegs, 
+                        Builder.getInt8((isI64 || (isF64 && IsSoftFloatABI)) ? 2 : 1));
     Builder.CreateStore(NumRegs, NumRegsAddr);
 
     CGF.EmitBranch(Cont);
@@ -7471,7 +7476,8 @@
     }
 
   case llvm::Triple::ppc:
-    return *(TheTargetCodeGenInfo = new PPC32TargetCodeGenInfo(Types));
+    return *(TheTargetCodeGenInfo = 
+             new PPC32TargetCodeGenInfo(Types, CodeGenOpts.FloatABI == "soft"));
   case llvm::Triple::ppc64:
     if (Triple.isOSBinFormatELF()) {
       PPC64_SVR4_ABIInfo::ABIKind Kind = PPC64_SVR4_ABIInfo::ELFv1;
Index: cfe/trunk/lib/Driver/Tools.h
===================================================================
--- cfe/trunk/lib/Driver/Tools.h
+++ cfe/trunk/lib/Driver/Tools.h
@@ -742,6 +742,16 @@
 FloatABI getARMFloatABI(const ToolChain &TC, const llvm::opt::ArgList &Args);
 } // end namespace arm
 
+namespace ppc {
+enum class FloatABI {
+  Invalid,
+  Soft,
+  Hard,
+};
+
+FloatABI getPPCFloatABI(const Driver &D, const llvm::opt::ArgList &Args);
+} // end namespace ppc
+
 namespace XCore {
 // For XCore, we do not need to instantiate tools for PreProcess, PreCompile and
 // Compile.
Index: cfe/trunk/lib/Driver/Tools.cpp
===================================================================
--- cfe/trunk/lib/Driver/Tools.cpp
+++ cfe/trunk/lib/Driver/Tools.cpp
@@ -1407,7 +1407,8 @@
   return "";
 }
 
-static void getPPCTargetFeatures(const ArgList &Args,
+static void getPPCTargetFeatures(const Driver &D, const llvm::Triple &Triple,
+                                 const ArgList &Args,
                                  std::vector<const char *> &Features) {
   for (const Arg *A : Args.filtered(options::OPT_m_ppc_Features_Group)) {
     StringRef Name = A->getOption().getName();
@@ -1431,11 +1432,51 @@
     Features.push_back(Args.MakeArgString((IsNegative ? "-" : "+") + Name));
   }
 
+  ppc::FloatABI FloatABI = ppc::getPPCFloatABI(D, Args);
+  if (FloatABI == ppc::FloatABI::Soft &&
+      !(Triple.getArch() == llvm::Triple::ppc64 ||
+        Triple.getArch() == llvm::Triple::ppc64le))
+    Features.push_back("+soft-float");
+  else if (FloatABI == ppc::FloatABI::Soft &&
+           (Triple.getArch() == llvm::Triple::ppc64 ||
+            Triple.getArch() == llvm::Triple::ppc64le))
+    D.Diag(diag::err_drv_invalid_mfloat_abi) 
+        << "soft float is not supported for ppc64";
+
   // Altivec is a bit weird, allow overriding of the Altivec feature here.
   AddTargetFeature(Args, Features, options::OPT_faltivec,
                    options::OPT_fno_altivec, "altivec");
 }
 
+ppc::FloatABI ppc::getPPCFloatABI(const Driver &D, const ArgList &Args) {
+  ppc::FloatABI ABI = ppc::FloatABI::Invalid;
+  if (Arg *A =
+          Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
+                          options::OPT_mfloat_abi_EQ)) {
+    if (A->getOption().matches(options::OPT_msoft_float))
+      ABI = ppc::FloatABI::Soft;
+    else if (A->getOption().matches(options::OPT_mhard_float))
+      ABI = ppc::FloatABI::Hard;
+    else {
+      ABI = llvm::StringSwitch<ppc::FloatABI>(A->getValue())
+                .Case("soft", ppc::FloatABI::Soft)
+                .Case("hard", ppc::FloatABI::Hard)
+                .Default(ppc::FloatABI::Invalid);
+      if (ABI == ppc::FloatABI::Invalid && !StringRef(A->getValue()).empty()) {
+        D.Diag(diag::err_drv_invalid_mfloat_abi) << A->getAsString(Args);
+        ABI = ppc::FloatABI::Hard;
+      }
+    }
+  }
+
+  // If unspecified, choose the default based on the platform.
+  if (ABI == ppc::FloatABI::Invalid) {
+    ABI = ppc::FloatABI::Hard;
+  }
+
+  return ABI;
+}
+
 void Clang::AddPPCTargetArgs(const ArgList &Args,
                              ArgStringList &CmdArgs) const {
   // Select the ABI to use.
@@ -1472,6 +1513,21 @@
     if (StringRef(A->getValue()) != "altivec")
       ABIName = A->getValue();
 
+  ppc::FloatABI FloatABI =
+      ppc::getPPCFloatABI(getToolChain().getDriver(), Args);
+
+  if (FloatABI == ppc::FloatABI::Soft) {
+    // Floating point operations and argument passing are soft.
+    CmdArgs.push_back("-msoft-float");
+    CmdArgs.push_back("-mfloat-abi");
+    CmdArgs.push_back("soft");
+  } else {
+    // Floating point operations and argument passing are hard.
+    assert(FloatABI == ppc::FloatABI::Hard && "Invalid float abi!");
+    CmdArgs.push_back("-mfloat-abi");
+    CmdArgs.push_back("hard");
+  }
+
   if (ABIName) {
     CmdArgs.push_back("-target-abi");
     CmdArgs.push_back(ABIName);
@@ -2248,7 +2304,7 @@
   case llvm::Triple::ppc:
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
-    getPPCTargetFeatures(Args, Features);
+    getPPCTargetFeatures(D, Triple, Args, Features);
     break;
   case llvm::Triple::systemz:
     getSystemZTargetFeatures(Args, Features);
Index: cfe/trunk/test/CodeGen/ppc-sfvarargs.c
===================================================================
--- cfe/trunk/test/CodeGen/ppc-sfvarargs.c
+++ cfe/trunk/test/CodeGen/ppc-sfvarargs.c
@@ -0,0 +1,17 @@
+// RUN: %clang -O0 --target=powerpc-unknown-linux-gnu -EB -msoft-float -S -emit-llvm %s -o - | FileCheck %s
+
+#include <stdarg.h>
+void test(char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  va_arg(ap, double);
+  va_end(ap);
+}
+
+void foo() {
+  double a;
+  test("test",a);
+}
+// CHECK: %{{[0-9]+}} = add i8 %numUsedRegs, 1
+// CHECK: %{{[0-9]+}} = and i8 %{{[0-9]+}}, -2
+// CHECK: %{{[0-9]+}} = mul i8 %{{[0-9]+}}, 4
\ No newline at end of file
Index: cfe/trunk/test/Driver/ppc-features.cpp
===================================================================
--- cfe/trunk/test/Driver/ppc-features.cpp
+++ cfe/trunk/test/Driver/ppc-features.cpp
@@ -12,6 +12,50 @@
 // RUN: not %clang -target mips64-linux-gnu -faltivec -fsyntax-only %s 2>&1 | FileCheck %s
 // RUN: not %clang -target sparc-unknown-solaris -faltivec -fsyntax-only %s 2>&1 | FileCheck %s
 
+// check -msoft-float option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -msoft-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-SOFTFLOAT %s
+// CHECK-SOFTFLOAT: "-target-feature" "+soft-float"
+
+// check -mfloat-abi=soft option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -mfloat-abi=soft -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-FLOATABISOFT %s
+// CHECK-FLOATABISOFT: "-target-feature" "+soft-float"
+
+// check -mhard-float option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -mhard-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-HARDFLOAT %s
+// CHECK-HARDFLOAT-NOT: "-target-feature" "+soft-float"
+
+// check -mfloat-abi=hard option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -mfloat-abi=hard -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-FLOATABIHARD %s
+// CHECK-FLOATABIHARD-NOT: "-target-feature" "+soft-float"
+
+// check combine -mhard-float -msoft-float option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -mhard-float -msoft-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-HARDSOFT %s
+// CHECK-HARDSOFT: "-target-feature" "+soft-float"
+
+// check combine -msoft-float -mhard-float option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -msoft-float -mhard-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-SOFTHARD %s
+// CHECK-SOFTHARD-NOT: "-target-feature" "+soft-float"
+
+// check -mfloat-abi=x option
+// RUN: %clang -target powerpc-unknown-linux-gnu %s -mfloat-abi=x -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-ERRMSG %s
+// CHECK-ERRMSG: clang: error: invalid float ABI '-mfloat-abi=x'
+
+// check -msoft-float option for ppc64
+// RUN: %clang -target powerpc64-unknown-linux-gnu %s -msoft-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-SOFTFLOAT64 %s
+// CHECK-SOFTFLOAT64: clang: error: invalid float ABI 'soft float is not supported for ppc64'
+
+// check -mfloat-abi=soft option for ppc64
+// RUN: %clang -target powerpc64-unknown-linux-gnu %s -mfloat-abi=soft -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-FLOATABISOFT64 %s
+// CHECK-FLOATABISOFT64: clang: error: invalid float ABI 'soft float is not supported for ppc64'
+
+// check -msoft-float option for ppc64
+// RUN: %clang -target powerpc64le-unknown-linux-gnu %s -msoft-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-SOFTFLOAT64le %s
+// CHECK-SOFTFLOAT64le: clang: error: invalid float ABI 'soft float is not supported for ppc64'
+
+// check -mfloat-abi=soft option for ppc64
+// RUN: %clang -target powerpc64le-unknown-linux-gnu %s -mfloat-abi=soft -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-FLOATABISOFT64le %s
+// CHECK-FLOATABISOFT64le: clang: error: invalid float ABI 'soft float is not supported for ppc64'
+
 // CHECK: invalid argument '-faltivec' only allowed with 'ppc/ppc64/ppc64le'
 
 // Check that -fno-altivec and -mno-altivec correctly disable the altivec