diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 4d3706c..49f662a 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -183,8 +183,16 @@ unsigned rs6000_pmode;
 unsigned rs6000_pointer_size;
 
 #ifdef HAVE_AS_GNU_ATTRIBUTE
-/* Flag whether floating point values have been passed/returned.  */
+# ifndef HAVE_LD_PPC_GNU_ATTR
+# define HAVE_LD_PPC_GNU_ATTR 0
+# endif
+/* Flag whether floating point values have been passed/returned.
+   Note that this doesn't say whether fprs are used, since the
+   Tag_GNU_Power_ABI_FP .gnu.attributes value this flag controls
+   should be set for soft-float values passed in gprs and ieee128
+   values passed in vsx registers.  */
 static bool rs6000_passes_float;
+static bool rs6000_passes_long_double;
 /* Flag whether vector values have been passed/returned.  */
 static bool rs6000_passes_vector;
 /* Flag whether small (<= 8 byte) structures have been returned.  */
@@ -10920,7 +10928,7 @@ rs6000_return_in_msb (const_tree valtype)
 static bool
 call_ABI_of_interest (tree fndecl)
 {
-  if (symtab->state == EXPANSION)
+  if (rs6000_gnu_attr && symtab->state == EXPANSION)
     {
       struct cgraph_node *c_node;
 
@@ -10997,7 +11005,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype,
     }
 
 #ifdef HAVE_AS_GNU_ATTRIBUTE
-  if (DEFAULT_ABI == ABI_V4)
+  if (TARGET_ELF && (TARGET_64BIT || DEFAULT_ABI == ABI_V4))
     {
       cum->escapes = call_ABI_of_interest (fndecl);
       if (cum->escapes)
@@ -11025,10 +11033,19 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype,
 		      <= 8))
 		rs6000_returns_struct = true;
 	    }
-	  if (SCALAR_FLOAT_MODE_NOT_VECTOR_P (return_mode))
-	    rs6000_passes_float = true;
-	  else if (ALTIVEC_OR_VSX_VECTOR_MODE (return_mode)
-		   || SPE_VECTOR_MODE (return_mode))
+	  if (SCALAR_FLOAT_MODE_P (return_mode))
+	    {
+	      rs6000_passes_float = true;
+	      if ((HAVE_LD_PPC_GNU_ATTR || TARGET_64BIT)
+		  && (FLOAT128_IBM_P (return_mode)
+		      || FLOAT128_IEEE_P (return_mode)
+		      || (return_type != NULL
+			  && (TYPE_MAIN_VARIANT (return_type)
+			      == long_double_type_node))))
+		rs6000_passes_long_double = true;
+	    }
+	  if (ALTIVEC_OR_VSX_VECTOR_MODE (return_mode)
+	      || SPE_VECTOR_MODE (return_mode))
 	    rs6000_passes_vector = true;
 	}
     }
@@ -11475,16 +11492,23 @@ rs6000_function_arg_advance_1 (CUMULATIVE_ARGS *cum, machine_mode mode,
     cum->nargs_prototype--;
 
 #ifdef HAVE_AS_GNU_ATTRIBUTE
-  if (DEFAULT_ABI == ABI_V4
+  if (TARGET_ELF && (TARGET_64BIT || DEFAULT_ABI == ABI_V4)
       && cum->escapes)
     {
-      if (SCALAR_FLOAT_MODE_NOT_VECTOR_P (mode))
-	rs6000_passes_float = true;
-      else if (named && ALTIVEC_OR_VSX_VECTOR_MODE (mode))
-	rs6000_passes_vector = true;
-      else if (SPE_VECTOR_MODE (mode)
-	       && !cum->stdarg
-	       && cum->sysv_gregno <= GP_ARG_MAX_REG)
+      if (SCALAR_FLOAT_MODE_P (mode))
+	{
+	  rs6000_passes_float = true;
+	  if ((HAVE_LD_PPC_GNU_ATTR || TARGET_64BIT)
+	      && (FLOAT128_IBM_P (mode)
+		  || FLOAT128_IEEE_P (mode)
+		  || (type != NULL
+		      && TYPE_MAIN_VARIANT (type) == long_double_type_node)))
+	    rs6000_passes_long_double = true;
+	}
+      if ((named && ALTIVEC_OR_VSX_VECTOR_MODE (mode))
+	  || (SPE_VECTOR_MODE (mode)
+	      && !cum->stdarg
+	      && cum->sysv_gregno <= GP_ARG_MAX_REG))
 	rs6000_passes_vector = true;
     }
 #endif
@@ -34292,13 +34316,21 @@ static void
 rs6000_elf_file_end (void)
 {
 #ifdef HAVE_AS_GNU_ATTRIBUTE
+  /* ??? The value emitted depends on options active at file end.
+     Assume anyone using #pragma or attributes that might change
+     options knows what they are doing.  */
+  if ((TARGET_64BIT || DEFAULT_ABI == ABI_V4)
+      && rs6000_passes_float)
+    fprintf (asm_out_file, "\t.gnu_attribute 4, %d\n",
+	     ((TARGET_DF_FPR | TARGET_DF_SPE ? 1
+	       : TARGET_SF_FPR | TARGET_SF_SPE ? 3
+	       : 2)
+	      | (!rs6000_passes_long_double ? 0
+		 : !TARGET_LONG_DOUBLE_128 ? 2 * 4
+		 : TARGET_IEEEQUAD ? 3 * 4
+		 : 1 * 4)));
   if (TARGET_32BIT && DEFAULT_ABI == ABI_V4)
     {
-      if (rs6000_passes_float)
-	fprintf (asm_out_file, "\t.gnu_attribute 4, %d\n",
-		 ((TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_DOUBLE_FLOAT) ? 1 
-		  : (TARGET_HARD_FLOAT && TARGET_FPRS && TARGET_SINGLE_FLOAT) ? 3 
-		  : 2));
       if (rs6000_passes_vector)
 	fprintf (asm_out_file, "\t.gnu_attribute 8, %d\n",
 		 (TARGET_ALTIVEC_ABI ? 2
@@ -37085,6 +37117,9 @@ static struct rs6000_opt_var const rs6000_opt_vars[] =
   { "warn-cell-microcode",
     offsetof (struct gcc_options, x_rs6000_warn_cell_microcode),
     offsetof (struct cl_target_option, x_rs6000_warn_cell_microcode), },
+  { "gnu-attr",
+    offsetof (struct gcc_options, x_rs6000_gnu_attr),
+    offsetof (struct cl_target_option, x_rs6000_gnu_attr), },
 };
 
 /* Inner function to handle attribute((target("..."))) and #pragma GCC target
diff --git a/gcc/config/rs6000/sysv4.opt b/gcc/config/rs6000/sysv4.opt
index 581fcde..d5b27cc 100644
--- a/gcc/config/rs6000/sysv4.opt
+++ b/gcc/config/rs6000/sysv4.opt
@@ -155,3 +155,7 @@ Generate code to use a non-exec PLT and GOT.
 mbss-plt
 Target Report RejectNegative Var(secure_plt, 0) Save
 Generate code for old exec BSS PLT.
+
+mgnu-attr
+Target Report Var(rs6000_gnu_attr) Init(-1) Save
+Emit .gnu_attribute tags.
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 534f22e..94912a0 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -5322,6 +5322,49 @@ if test "x$gcc_cv_ld_clearcap" = xyes; then
 fi
 AC_MSG_RESULT($gcc_cv_ld_clearcap)
 
+case "$target" in
+  powerpc*-*-*)
+    case "$target" in
+      *le-*-linux*)
+	emul_name="-melf32lppc"
+	;;
+      *)
+	emul_name="-melf32ppc"
+	;;
+    esac
+    AC_CACHE_CHECK(linker .gnu_attribute long double support,
+    gcc_cv_ld_ppc_attr,
+    [gcc_cv_ld_ppc_attr=no
+    if test x"$ld_is_gold" = xyes; then
+      gcc_cv_ld_ppc_attr=yes
+    elif test $in_tree_ld = yes ; then
+      if test "$gcc_cv_gld_major_version" -eq 2 -a "$gcc_cv_gld_minor_version" -ge 28 -o "$gcc_cv_gld_major_version" -gt 2; then
+        gcc_cv_ld_ppc_attr=yes
+      fi
+    elif test x$gcc_cv_as != x -a x$gcc_cv_ld != x ; then
+      # check that merging the long double .gnu_attribute doesn't warn
+      cat > conftest1.s <<EOF
+	.gnu_attribute 4,1
+EOF
+      cat > conftest2.s <<EOF
+	.gnu_attribute 4,9
+EOF
+      if $gcc_cv_as -a32 -o conftest1.o conftest1.s > /dev/null 2>&1 \
+         && $gcc_cv_as -a32 -o conftest2.o conftest2.s > /dev/null 2>&1 \
+         && $gcc_cv_ld $emul_name -r -o conftest.o conftest1.o conftest2.o > /dev/null 2> conftest.err \
+	 && test ! -s conftest.err; then
+        gcc_cv_ld_ppc_attr=yes
+      fi
+      rm -f conftest.err conftest.o conftest1.o conftest2.o conftest1.s conftest2.s
+    fi
+    ])
+    if test x$gcc_cv_ld_ppc_attr = xyes; then
+      AC_DEFINE(HAVE_LD_PPC_GNU_ATTR, 1,
+    [Define if your PowerPC linker has .gnu_attribute long double support.])
+    fi
+    ;;
+esac
+
 case "$target:$tm_file" in
   powerpc64-*-freebsd* | powerpc64*-*-linux* | powerpc*-*-linux*rs6000/biarch64.h*)
   case "$target" in
