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doc/building.md
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libffi-devel`.
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.
+
+You can enable this library by specifying a library prefix
+via `--with-sflt=<path>` or by specifying path to softfloat.a
+via `--with-sflt-lib=<path>` and path to directory
+containing softfloat.h via `--with-sflt-include=<path>`. You
+will also need to specify path to the SoftFloat license file with
+`--with-sflt-license=<path>`. If you want to use the prefix option, ensure that
+`<prefix>/lib/softfloat.a`, `<prefix>/include/softfloat.h` and
+`<prefix>/share/softfloat/softfloat.md` exist. However you can override
+the defaults by using the options above.
+
+If you do not enable this library, standard system libraries
+will be used instead.
+
## Build Tools Requirements
### Autoconf
The JDK requires [Autoconf](http://www.gnu.org/software/autoconf) on all
@@ -692,10 +718,12 @@
* `--with-freetype=<path>` - Set the path to [FreeType](#freetype)
* `--with-cups=<path>` - Set the path to [CUPS](#cups)
* `--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)
+ * `--with-sflt=<path>` - Enable and set the path to [SoftFloat](#softfloat)
+ library.
* `--with-jtreg=<path>` - Set the path to JTReg. See [Running Tests](
#running-tests)
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
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