Reference
http://blogs.bu.edu/mhirsch/2013/12/compiling-octave-3-8/


(Ubuntu 12.04.4)
./configure --enable-jit --prefix=/opt/octave3.8 LLVM_CONFIG=~/Downloads/clang+llvm-3.2-x86_64-linux-ubuntu-12.04/bin/llvm-config


sudo ./configure LLVM_CONFIG=/usr/bin/llvm-config-3.2 JAVA_HOME=/usr/lib/jvm/default-java --enable-jit --prefix=/opt/octave3.8


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
mapx@N55SL:~/xfiles/gnuoctave/octave-3.8.1$ ./configure JAVA_HOME=/usr/lib/jvm/default-java --enable-jit --prefix=/opt/octave3.8 LLVM_CONFIG=/home/mapx/xfiles/gnuoctave/clang+llvm-3.2-x86_64-linux-ubuntu-12.04/bin/llvm-config

.
.
.
.

  Build Octave GUI:                   yes
  JIT compiler for loops:             no
  Build Java interface:               yes
  Do internal array bounds checking:  no
  Use octave_allocator:               no
  Build static libraries:             no
  Build shared libraries:             yes
  Dynamic Linking:                    yes (dlopen)
  Include support for GNU readline:   yes
  64-bit array dims and indexing:     no

configure: WARNING: Missing LLVM file TargetData.h.  JIT compiler is disabled.
configure:
configure: NOTE: Libraries or auxiliary programs may be skipped if they are
configure: NOTE: not found OR if they are missing required features on your
configure: NOTE: system.


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
$ make
.
.
.


make[3]: `../../INSTALL.OCTAVE' is up to date.
make[3]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1/doc/interpreter'

Octave successfully built.  Now choose from the following:

   ./run-octave    - to run in place to test before installing
   make check      - to run the tests
   make install    - to install (PREFIX=/opt/octave3.8)

make[2]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1'
make[1]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1'





+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
$ make check
.
.
.

unwind.tst ............................................. PASS    2/2
  while.tst .............................................. PASS    6/6

Summary:

  PASS     11503
  FAIL         0
  XFAIL        7
  SKIPPED     36

See the file test/fntests.log for additional details.

Expected failures (listed as XFAIL above) are known bugs.
Please help improve Octave by contributing fixes for them.

Tests are most often skipped because the features they require
have been disabled.  Features are most often disabled because
they require dependencies that were not present when Octave
was built.  The configure script should have printed a summary
at the end of its run indicating which dependencies were not found.

243 (of 831) .m files have no tests.

Please help improve Octave by contributing tests for
these files (see the list in the file fntests.log).

make[1]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1/test'


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
$ sudo make install
[sudo] password for mapx:


.
.
.
Octave successfully built.  Now choose from the following:

   ./run-octave    - to run in place to test before installing
   make check      - to run the tests
   make install    - to install (PREFIX=/opt/octave3.8)

make[3]: Entering directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1'
Makefile:2835: warning: overriding commands for target `check'
Makefile:2397: warning: ignoring old commands for target `check'
make[3]: Nothing to be done for `install-exec-am'.
/bin/mkdir -p /opt/octave3.8/share/octave/site/m /opt/octave3.8/share/octave/site/api-v49+/m /opt/octave3.8/share/octave/3.8.1/site/m /opt/octave3.8/lib/octave/site/oct/i686-pc-linux-gnu /opt/octave3.8/lib/octave/site/oct/api-v49+/i686-pc-linux-gnu /opt/octave3.8/lib/octave/3.8.1/site/oct/i686-pc-linux-gnu /opt/octave3.8/libexec/octave/site/exec/i686-pc-linux-gnu /opt/octave3.8/libexec/octave/api-v49+/site/exec/i686-pc-linux-gnu /opt/octave3.8/libexec/octave/3.8.1/site/exec/i686-pc-linux-gnu
 /bin/mkdir -p '/opt/octave3.8/include/octave-3.8.1/octave'
 /usr/bin/install -c -m 644 config.h '/opt/octave3.8/include/octave-3.8.1/octave'
 /bin/mkdir -p '/opt/octave3.8/share/octave/3.8.1/etc'
 /usr/bin/install -c -m 644 CITATION NEWS config.log '/opt/octave3.8/share/octave/3.8.1/etc'
 /bin/mkdir -p '/opt/octave3.8/include/octave-3.8.1/octave'
 /usr/bin/install -c -m 644 oct-conf-post.h '/opt/octave3.8/include/octave-3.8.1/octave'
make[3]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1'
make[2]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1'
make[1]: Leaving directory `/home/mapx/xfiles/gnuoctave/octave-3.8.1'


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
$ sudo ln -s /opt/octave3.8/bin/octave /usr/local/bin/octave3.8


Now to run Octave 3.8 with GUI, at Terminal type:
octave3.8 --force-gui

You can of course make a bash alias to always add that –force-gui for you.

nano ~/.bash_aliases
and add the line
alias octave38="octave3.8 --force-gui"