softfloat.patch

# HG changeset patch
# User Jakub Vaněk <linuxtardis@gmail.com>
# Date 1544273385 -3600
#      Sat Dec 08 13:49:45 2018 +0100
# Node ID 2dda78cf712d402b53df779325e8b8f23b487be2
# Parent  583fd71c47d60dea883b1f03d9f1b2c267c0a891
Add support for compiling with SoftFloat-3e on arm sflt builds

diff --git a/doc/building.html b/doc/building.html
--- a/doc/building.html
+++ b/doc/building.html
@@ -53,6 +53,7 @@
 <li><a href="#x11">X11</a></li>
 <li><a href="#alsa">ALSA</a></li>
 <li><a href="#libffi">libffi</a></li>
+<li><a href="#softfloat">SoftFloat</a></li>
 </ul></li>
 <li><a href="#build-tools-requirements">Build Tools Requirements</a><ul>
 <li><a href="#autoconf">Autoconf</a></li>
@@ -415,6 +416,14 @@
 <li>To install on an rpm-based Linux, try running <code>sudo yum install libffi-devel</code>.</li>
 </ul>
 <p>Use <code>--with-libffi=&lt;path&gt;</code> if <code>configure</code> does not properly locate your libffi files.</p>
+
+<h3 id="softfloat">SoftFloat</h3>
+<p><a href="http://www.jhauser.us/arithmetic/SoftFloat.html">Berkeley SoftFloat-3</a> can be used on ARM processors without FPU to slightly enhance the arithmetic precision of some floating point operations. It is not required, system softfp routines can be used without any problems. The precision loss is extremely small, but <a href="http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html">the JCK detects it</a>.</p>
+<ul>
+<li>To build the library, you will have to download its source and build it for the target platform. To do so, take a look in its <code>build/Linux-ARM-VFPv2-GCC</code> subdirectory.</li>
+</ul>
+<p>Use <code>--enable-softfloat</code> to enable the use of this library. You can then use <code>--with-softfloat-lib=&lt;path&gt;</code> and <code>--with-softfloat-include=&lt;path&gt;</code> to specify the path to the <code>softfloat.a</code> archive and the <code>source/include</code> directory. Alternatively, if you install the library and its headers to a prefix, you can pass its path to <code>--with-softfloat=&lt;path&gt;</code>.</p>
+<p>If you do not enable this library, standard system libraries will be used instead.</p>
 <h2 id="build-tools-requirements">Build Tools Requirements</h2>
 <h3 id="autoconf">Autoconf</h3>
 <p>The JDK requires <a href="http://www.gnu.org/software/autoconf">Autoconf</a> on all platforms. At least version 2.69 is required.</p>
@@ -486,6 +495,8 @@
 <li><code>--with-x=&lt;path&gt;</code> - Set the path to <a href="#x11">X11</a></li>
 <li><code>--with-alsa=&lt;path&gt;</code> - Set the path to <a href="#alsa">ALSA</a></li>
 <li><code>--with-libffi=&lt;path&gt;</code> - Set the path to <a href="#libffi">libffi</a></li>
+<li><code>--enable-softfloat</code> - Enable the use of external <a href="#softfloat">SoftFloat</a> library on sflt builds.</li>
+<li><code>--with-softfloat=&lt;path&gt;</code> or <code>--with-softfloat-lib=&lt;path&gt;</code>, <code>--with-softfloat-include=&lt;path&gt;</code> - Set the path to <a href="#softfloat">SoftFloat</a> library and include directory.</li>
 <li><code>--with-jtreg=&lt;path&gt;</code> - Set the path to JTReg. See <a href="#running-tests">Running Tests</a></li>
 </ul>
 <p>Certain third-party libraries used by the JDK (libjpeg, giflib, libpng, lcms and zlib) are included in the JDK repository. The default behavior of the JDK build is to use this version of these libraries, but they might be replaced by an external version. To do so, specify <code>system</code> as the <code>&lt;source&gt;</code> option in these arguments. (The default is <code>bundled</code>).</p>
diff --git a/doc/building.md b/doc/building.md
--- a/doc/building.md
+++ b/doc/building.md
@@ -527,6 +527,28 @@
 Use `--with-libffi=<path>` if `configure` does not properly locate your libffi
 files.
 
+### SoftFloat
+
+[Berkeley SoftFloat-3](http://www.jhauser.us/arithmetic/SoftFloat.html)
+can be used on ARM processors without FPU to slightly enhance
+the arithmetic precision of some floating point operations. It is not
+required, system softfp routines can be used without any problems.
+The precision loss is extremely small, but [the JCK detects it](
+http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html).
+
+  * To build the library, you will have to download its source and build it
+    for the target platform. To do so, take a look in its
+    `build/Linux-ARM-VFPv2-GCC` subdirectory.
+
+Use `--enable-softfloat` to enable the use of this library. You can then
+use `--with-softfloat-lib=<path>` and `--with-softfloat-include=<path>`
+to specify the path to the `softfloat.a` archive and the `source/include`
+directory. Alternatively, if you install the library and its headers to
+a prefix, you can pass its path to `--with-softfloat=<path>`.
+
+If you do not enable this library, standard system libraries
+will be used instead.
+
 ## Build Tools Requirements
 
 ### Autoconf
@@ -694,6 +716,10 @@
   * `--with-x=<path>` - Set the path to [X11](#x11)
   * `--with-alsa=<path>` - Set the path to [ALSA](#alsa)
   * `--with-libffi=<path>` - Set the path to [libffi](#libffi)
+  * `--enable-softfloat` - Enable the use of external [SoftFloat](#softfloat)
+    library on sflt builds.
+  * `--with-softfloat=<path>` or `--with-softfloat-lib=<path>`, `--with-softfloat-include=<path>` -
+    Set the path to [SoftFloat](#softfloat) library and include directory.
   * `--with-jtreg=<path>` - Set the path to JTReg. See [Running Tests](
     #running-tests)
 
diff --git a/make/autoconf/lib-softfloat.m4 b/make/autoconf/lib-softfloat.m4
new file mode 100644
--- /dev/null
+++ b/make/autoconf/lib-softfloat.m4
@@ -0,0 +1,149 @@
+#
+# Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# This code is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License version 2 only, as
+# published by the Free Software Foundation.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# This code is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# version 2 for more details (a copy is included in the LICENSE file that
+# accompanied this code).
+#
+# You should have received a copy of the GNU General Public License version
+# 2 along with this work; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+# or visit www.oracle.com if you need additional information or have any
+# questions.
+#
+
+################################################################################
+# Setup softfloat library
+################################################################################
+AC_DEFUN_ONCE([LIB_SETUP_SOFTFLOAT],
+[
+  # define options
+  AC_ARG_ENABLE(softfloat, [AS_HELP_STRING([--enable-softfloat],
+      [enable use of SoftFloat-3 on softfp builds])])
+
+  AC_ARG_WITH(softfloat, [AS_HELP_STRING([--with-softfloat],
+      [specify prefix directory for the softfloat package
+      (expecting softfloat.a under PATH/lib and softfloat.h under PATH/include)])])
+
+  AC_ARG_WITH(softfloat-lib, [AS_HELP_STRING([--with-softfloat-lib],
+      [specify the path to SoftFloat-3 static library])])
+
+  AC_ARG_WITH(softfloat-include, [AS_HELP_STRING([--with-softfloat-include],
+      [specify the path to SoftFloat-3 include directory])])
+
+  # check if softfloat can be used and if the user enabled it
+  AC_MSG_CHECKING([if softfloat library should be used])
+  if test "x$USES_LIB_SOFTFLOAT" = "xtrue"; then
+
+    if test "x$enable_softfloat" = "x" || test "x$enable_softfloat" = "xno"; then
+      AC_MSG_RESULT([no, system softfp used])
+      AC_MSG_NOTICE([Floating point operations may be less precise by a very small amount])
+      SOFTFLOAT_ENABLED=no
+
+    elif  test "x$enable_softfloat" = "xyes"; then
+      AC_MSG_RESULT([yes])
+      SOFTFLOAT_ENABLED=yes
+    else
+      AC_MSG_ERROR([Invalid value for --enable-softfloat])
+    fi
+
+  else
+    AC_MSG_RESULT([no, not needed])
+    if test "x${enable_softfloat}" != x && test "x${enable_softfloat}" != xno; then
+      AC_MSG_WARN([[not building for sflt, so --enable-softfloat is ignored]])
+    fi
+    if test "x${with_softfloat}" != x && test "x${with_softfloat}" != xno; then
+      AC_MSG_WARN([[not building for sflt, so --with-softfloat is ignored]])
+    fi
+    if test "x${with_softfloat_lib}" != x && test "x${with_softfloat_lib}" != xno; then
+      AC_MSG_WARN([[not building for sflt, so --with-softfloat-lib is ignored]])
+    fi
+    if test "x${with_softfloat_include}" != x && test "x${with_softfloat_include}" != xno; then
+      AC_MSG_WARN([[not building for sflt, so --with-softfloat-include is ignored]])
+    fi
+    SOFTFLOAT_ENABLED=no
+  fi
+
+  # if the library can be used and the user wants it, find it and test it
+  if test "x$SOFTFLOAT_ENABLED" = "xyes"; then
+    SOFTFLOAT_FOUND=no
+
+    if test "x${with_softfloat}" = xno || test "x${with_softfloat_lib}" = xno || test "x${with_softfloat_include}" = xno; then
+      AC_MSG_ERROR([Please do not combine --enable-softfloat and --without-softfloat* options.])
+    fi
+
+    if test "x${with_softfloat}" != x; then
+      SOFTFLOAT_CFLAGS="-I${with_softfloat}/include -DSOFTFLOAT_EXTERNAL"
+      SOFTFLOAT_LIBS="${with_softfloat}/lib/softfloat.a"
+      SOFTFLOAT_FOUND=yes
+    fi
+    if test "x${with_softfloat_include}" != x; then
+      SOFTFLOAT_CFLAGS="-I${with_softfloat_include} -DSOFTFLOAT_EXTERNAL"
+      SOFTFLOAT_FOUND=yes
+    fi
+    if test "x${with_softfloat_lib}" != x; then
+      SOFTFLOAT_LIBS="${with_softfloat_lib}"
+      SOFTFLOAT_FOUND=yes
+    fi
+    if test "x$SOFTFLOAT_FOUND" = xno; then
+      AC_CHECK_HEADERS([softfloat.h],
+          [
+            SOFTFLOAT_FOUND=yes
+            SOFTFLOAT_CFLAGS="-DSOFTFLOAT_EXTERNAL"
+            SOFTFLOAT_LIBS="-l:softfloat.a"
+          ],
+          [SOFTFLOAT_FOUND=no]
+      )
+    fi
+    if test "x$SOFTFLOAT_FOUND" = xno; then
+      HELP_MSG_MISSING_DEPENDENCY([softfloat])
+      AC_MSG_ERROR([Could not find softfloat! $HELP_MSG])
+    else
+      AC_MSG_CHECKING([for softfloat library])
+      AC_MSG_RESULT([$SOFTFLOAT_LIBS])
+
+      AC_MSG_CHECKING([for softfloat compiler flags])
+      AC_MSG_RESULT([$SOFTFLOAT_CFLAGS])
+    fi
+
+    AC_MSG_CHECKING([if softfloat works])
+    AC_LANG_PUSH(C)
+    OLD_CFLAGS="$CFLAGS"
+    CFLAGS="$CFLAGS $SOFTFLOAT_CFLAGS"
+    OLD_LIBS="$LIBS"
+    LIBS="$LIBS $SOFTFLOAT_LIBS"
+    AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <softfloat.h>],
+        [
+          return f32_to_i32(f32_sub(i32_to_f32(1), i32_to_f32(1)), softfloat_round_near_even, false);
+        ])],
+        [SOFTFLOAT_WORKS=yes],
+        [SOFTFLOAT_WORKS=no]
+    )
+    CFLAGS="$OLD_CFLAGS"
+    LIBS="$OLD_LIBS"
+    AC_LANG_POP(C)
+    AC_MSG_RESULT([$SOFTFLOAT_WORKS])
+
+    if test "x$SOFTFLOAT_WORKS" = xno; then
+      HELP_MSG_MISSING_DEPENDENCY([softfloat])
+      AC_MSG_ERROR([Found softfloat but could not link and compile with it. $HELP_MSG])
+    fi
+  else
+    SOFTFLOAT_CFLAGS=
+    SOFTFLOAT_LIBS=
+  fi
+
+  AC_SUBST(SOFTFLOAT_LIBS)
+  AC_SUBST(SOFTFLOAT_CFLAGS)
+])
diff --git a/make/autoconf/libraries.m4 b/make/autoconf/libraries.m4
--- a/make/autoconf/libraries.m4
+++ b/make/autoconf/libraries.m4
@@ -33,6 +33,7 @@
 m4_include([lib-x11.m4])
 m4_include([lib-fontconfig.m4])
 m4_include([lib-tests.m4])
+m4_include([lib-softfloat.m4])
 
 ################################################################################
 # Determine which libraries are needed for this configuration
@@ -79,6 +80,13 @@
     NEEDS_LIB_ALSA=false
   fi
 
+  if (test "x$OPENJDK_TARGET_CPU" == xarm &&
+      (test "x$ARM_FLOAT_TYPE" = "xsflt" || test "x$ARM_FLOAT_TYPE" = "xvfp-sflt" )); then
+    USES_LIB_SOFTFLOAT=true
+  else
+    USES_LIB_SOFTFLOAT=false
+  fi
+
   # Check if ffi is needed
   if HOTSPOT_CHECK_JVM_VARIANT(zero); then
     NEEDS_LIB_FFI=true
@@ -98,6 +106,7 @@
   LIB_SETUP_FONTCONFIG
   LIB_SETUP_FREETYPE
   LIB_SETUP_ALSA
+  LIB_SETUP_SOFTFLOAT
   LIB_SETUP_LIBFFI
   LIB_SETUP_BUNDLED_LIBS
   LIB_SETUP_MISC_LIBS
diff --git a/make/autoconf/spec.gmk.in b/make/autoconf/spec.gmk.in
--- a/make/autoconf/spec.gmk.in
+++ b/make/autoconf/spec.gmk.in
@@ -353,6 +353,8 @@
 CUPS_CFLAGS:=@CUPS_CFLAGS@
 ALSA_LIBS:=@ALSA_LIBS@
 ALSA_CFLAGS:=@ALSA_CFLAGS@
+SOFTFLOAT_LIBS:=@SOFTFLOAT_LIBS@
+SOFTFLOAT_CFLAGS:=@SOFTFLOAT_CFLAGS@
 LIBFFI_LIBS:=@LIBFFI_LIBS@
 LIBFFI_CFLAGS:=@LIBFFI_CFLAGS@
 ENABLE_LIBFFI_BUNDLING:=@ENABLE_LIBFFI_BUNDLING@
diff --git a/make/copy/Copy-java.base.gmk b/make/copy/Copy-java.base.gmk
--- a/make/copy/Copy-java.base.gmk
+++ b/make/copy/Copy-java.base.gmk
@@ -219,6 +219,10 @@
   LEGAL_EXCLUDES += zlib.md
 endif
 
+ifeq ($(SOFTFLOAT_LIBS), )
+  LEGAL_EXCLUDES += softfloat.md
+endif
+
 $(eval $(call SetupCopyLegalFiles, COPY_LEGAL, \
     EXCLUDES := $(LEGAL_EXCLUDES), \
 ))
diff --git a/make/hotspot/lib/CompileJvm.gmk b/make/hotspot/lib/CompileJvm.gmk
--- a/make/hotspot/lib/CompileJvm.gmk
+++ b/make/hotspot/lib/CompileJvm.gmk
@@ -49,6 +49,7 @@
 
 JVM_LIBS += \
     $(JVM_LIBS_FEATURES) \
+    $(SOFTFLOAT_LIBS) \
     #
 
 # These files and directories are always excluded
diff --git a/make/hotspot/lib/JvmFlags.gmk b/make/hotspot/lib/JvmFlags.gmk
--- a/make/hotspot/lib/JvmFlags.gmk
+++ b/make/hotspot/lib/JvmFlags.gmk
@@ -88,6 +88,7 @@
     $(JVM_CFLAGS_TARGET_DEFINES) \
     $(JVM_CFLAGS_FEATURES) \
     $(JVM_CFLAGS_INCLUDES) \
+    $(SOFTFLOAT_CFLAGS) \
     $(EXTRA_CFLAGS) \
     #
 
diff --git a/src/hotspot/cpu/arm/assembler_arm_32.hpp b/src/hotspot/cpu/arm/assembler_arm_32.hpp
--- a/src/hotspot/cpu/arm/assembler_arm_32.hpp
+++ b/src/hotspot/cpu/arm/assembler_arm_32.hpp
@@ -1242,10 +1242,10 @@
 
 // Imported code from glibc soft-fp bundle for
 // calculation accuracy improvement. See CR 6757269.
-extern double __aeabi_fadd_glibc(float, float);
-extern double __aeabi_fsub_glibc(float, float);
-extern double __aeabi_dadd_glibc(double, double);
-extern double __aeabi_dsub_glibc(double, double);
+extern float __aeabi_fadd_extlib(float, float);
+extern float __aeabi_fsub_extlib(float, float);
+extern double __aeabi_dadd_extlib(double, double);
+extern double __aeabi_dsub_extlib(double, double);
 };
 #endif // __SOFTFP__
 
diff --git a/src/hotspot/cpu/arm/c1_LIRGenerator_arm.cpp b/src/hotspot/cpu/arm/c1_LIRGenerator_arm.cpp
--- a/src/hotspot/cpu/arm/c1_LIRGenerator_arm.cpp
+++ b/src/hotspot/cpu/arm/c1_LIRGenerator_arm.cpp
@@ -490,27 +490,28 @@
     // Call function compiled with -msoft-float.
 
       // __aeabi_XXXX_glibc: Imported code from glibc soft-fp bundle for calculation accuracy improvement. See CR 6757269.
+      // http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html
 
     case Bytecodes::_fadd:
-      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fadd_glibc);
+      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fadd_extlib);
       break;
     case Bytecodes::_fmul:
       runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fmul);
       break;
     case Bytecodes::_fsub:
-      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fsub_glibc);
+      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fsub_extlib);
       break;
     case Bytecodes::_fdiv:
       runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fdiv);
       break;
     case Bytecodes::_dadd:
-      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dadd_glibc);
+      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dadd_extlib);
       break;
     case Bytecodes::_dmul:
       runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dmul);
       break;
     case Bytecodes::_dsub:
-      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dsub_glibc);
+      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dsub_extlib);
       break;
     case Bytecodes::_ddiv:
       runtime_func = CAST_FROM_FN_PTR(address, __aeabi_ddiv);
diff --git a/src/hotspot/cpu/arm/c1_Runtime1_arm.cpp b/src/hotspot/cpu/arm/c1_Runtime1_arm.cpp
--- a/src/hotspot/cpu/arm/c1_Runtime1_arm.cpp
+++ b/src/hotspot/cpu/arm/c1_Runtime1_arm.cpp
@@ -804,15 +804,16 @@
 #define FUNCTION_CASE(a, f) \
   if ((intptr_t)a == CAST_FROM_FN_PTR(intptr_t, f))  return #f
 
-  FUNCTION_CASE(entry, __aeabi_fadd_glibc);
+  // __aeabi_XXXX_glibc: Imported code from glibc soft-fp bundle for calculation accuracy improvement. See CR 6757269.
+  // http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html
+  FUNCTION_CASE(entry, __aeabi_fadd_extlib);
   FUNCTION_CASE(entry, __aeabi_fmul);
-  FUNCTION_CASE(entry, __aeabi_fsub_glibc);
+  FUNCTION_CASE(entry, __aeabi_fsub_extlib);
   FUNCTION_CASE(entry, __aeabi_fdiv);
 
-  // __aeabi_XXXX_glibc: Imported code from glibc soft-fp bundle for calculation accuracy improvement. See CR 6757269.
-  FUNCTION_CASE(entry, __aeabi_dadd_glibc);
+  FUNCTION_CASE(entry, __aeabi_dadd_extlib);
   FUNCTION_CASE(entry, __aeabi_dmul);
-  FUNCTION_CASE(entry, __aeabi_dsub_glibc);
+  FUNCTION_CASE(entry, __aeabi_dsub_extlib);
   FUNCTION_CASE(entry, __aeabi_ddiv);
 
   FUNCTION_CASE(entry, __aeabi_f2d);
diff --git a/src/hotspot/cpu/arm/softfloat_arm.cpp b/src/hotspot/cpu/arm/softfloat_arm.cpp
new file mode 100644
--- /dev/null
+++ b/src/hotspot/cpu/arm/softfloat_arm.cpp
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifdef __SOFTFP__
+
+// Soft float function declarations
+extern "C" {
+    extern float  __aeabi_fadd(float, float);
+    extern float  __aeabi_fsub(float, float);
+    extern double __aeabi_dadd(double, double);
+    extern double __aeabi_dsub(double, double);
+
+    extern float __aeabi_fadd_extlib(float, float);
+    extern float __aeabi_fsub_extlib(float, float);
+    extern double __aeabi_dadd_extlib(double, double);
+    extern double __aeabi_dsub_extlib(double, double);
+};
+
+#ifdef SOFTFLOAT_EXTERNAL
+
+extern "C" {
+#include "softfloat.h"
+}
+
+#include <cstring>
+
+static float __aeabi_float_handling(float natA, float natB, bool add) {
+    float32_t libA;
+    float32_t libB;
+    float32_t libC;
+    float natC;
+
+    memcpy(&libA, &natA, sizeof(libA));
+    memcpy(&libB, &natB, sizeof(libB));
+    libC = add ? f32_add(libA, libB) : f32_sub(libA, libB);
+    memcpy(&natC, &libC, sizeof(libC));
+
+    return natC;
+}
+
+static double __aeabi_double_handling(double natA, double natB, bool add) {
+    float64_t libA;
+    float64_t libB;
+    float64_t libC;
+    double natC;
+
+    memcpy(&libA, &natA, sizeof(libA));
+    memcpy(&libB, &natB, sizeof(libB));
+    libC = add ? f64_add(libA, libB) : f64_sub(libA, libB);
+    memcpy(&natC, &libC, sizeof(libC));
+
+    return natC;
+}
+
+float __aeabi_fadd_extlib(float a, float b) {
+    return __aeabi_float_handling(a, b, true);
+}
+
+float __aeabi_fsub_extlib(float a, float b) {
+    return __aeabi_float_handling(a, b, false);
+}
+
+double __aeabi_dadd_extlib(double a, double b) {
+    return __aeabi_double_handling(a, b, true);
+}
+
+double __aeabi_dsub_extlib(double a, double b) {
+    return __aeabi_double_handling(a, b, false);
+}
+
+#else
+
+float __aeabi_fadd_extlib(float a, float b) {
+    return __aeabi_fadd(a, b);
+}
+
+float __aeabi_fsub_extlib(float a, float b) {
+    return __aeabi_fsub(a, b);
+}
+
+double __aeabi_dadd_extlib(double a, double b) {
+    return __aeabi_dadd(a, b);
+}
+
+double __aeabi_dsub_extlib(double a, double b) {
+    return __aeabi_dsub(a, b);
+}
+
+#endif
+
+#endif // __SOFTFP__
diff --git a/src/hotspot/cpu/arm/templateTable_arm.cpp b/src/hotspot/cpu/arm/templateTable_arm.cpp
--- a/src/hotspot/cpu/arm/templateTable_arm.cpp
+++ b/src/hotspot/cpu/arm/templateTable_arm.cpp
@@ -1610,8 +1610,10 @@
   __ mov(R1, R0_tos);
   __ pop_i(R0);
   switch (op) {
-    case add: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_fadd_glibc), R0, R1); break;
-    case sub: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_fsub_glibc), R0, R1); break;
+    // __aeabi_XXXX_glibc: Imported code from glibc soft-fp bundle for calculation accuracy improvement. See CR 6757269.
+    // http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html
+    case add: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_fadd_extlib), R0, R1); break;
+    case sub: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_fsub_extlib), R0, R1); break;
     case mul: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_fmul), R0, R1); break;
     case div: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_fdiv), R0, R1); break;
     case rem: __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::frem), R0, R1); break;
@@ -1653,8 +1655,9 @@
   __ pop_l(R0, R1);
   switch (op) {
     // __aeabi_XXXX_glibc: Imported code from glibc soft-fp bundle for calculation accuracy improvement. See CR 6757269.
-    case add: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_dadd_glibc), R0, R1, R2, R3); break;
-    case sub: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_dsub_glibc), R0, R1, R2, R3); break;
+    // http://mail.openjdk.java.net/pipermail/aarch32-port-dev/2016-November/000611.html
+    case add: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_dadd_extlib), R0, R1, R2, R3); break;
+    case sub: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_dsub_extlib), R0, R1, R2, R3); break;
     case mul: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_dmul), R0, R1, R2, R3); break;
     case div: __ call_VM_leaf(CAST_FROM_FN_PTR(address, __aeabi_ddiv), R0, R1, R2, R3); break;
     case rem: __ call_VM_leaf(CAST_FROM_FN_PTR(address, SharedRuntime::drem), R0, R1, R2, R3); break;
diff --git a/src/java.base/share/legal/softfloat.md b/src/java.base/share/legal/softfloat.md
new file mode 100644
--- /dev/null
+++ b/src/java.base/share/legal/softfloat.md
@@ -0,0 +1,40 @@
+## SoftFloat-3e
+
+### SoftFloat license
+```
+License for Berkeley SoftFloat Release 3e
+
+John R. Hauser
+2018 January 20
+
+The following applies to the whole of SoftFloat Release 3e as well as to
+each source file individually.
+
+Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 The Regents of the
+University of California.  All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+    this list of conditions, and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions, and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+
+ 3. Neither the name of the University nor the names of its contributors
+    may be used to endorse or promote products derived from this software
+    without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
+EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
+DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+```