Common platform:
Bits: int=32, long=32, long long=64, void*=32
CFLAGS: -Wno-unused-result -Werror=declaration-after-statement -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes
Python unicode implementation: PEP 393
Timer info: namespace(adjustable=False, implementation='clock_gettime(CLOCK_MONOTONIC)', monotonic=True, resolution=1e-09)
Timer: time.perf_counter
Platform: Linux-3.0.8+-armv7l-with-debian-wheezy-sid

Platform of campaign original.txt:
Python version: 3.4.0a0 (default:25450fff5b90, Jun 2 2013, 14:52:05) [GCC 4.7.2]
Date: 2013-06-02 15:24:54
SCM: hg revision=25450fff5b90 tag=tip branch=default date="2013-06-01 11:12 -0700"
Timer precision: 916 ns

Platform of campaign patched.txt:
Python version: 3.4.0a0 (default:25450fff5b90+, Jun 2 2013, 16:02:29) [GCC 4.7.2]
Date: 2013-06-02 16:03:46
SCM: hg revision=25450fff5b90+ tag=tip branch=default date="2013-06-01 11:12 -0700"
Timer precision: 833 ns

-----------------------+--------------+---------------
Length 1               | original.txt |    patched.txt
-----------------------+--------------+---------------
hash('a' * 1)          |   471 ns (*) |  860 ns (+83%)
hash('\u20ac' * 1)     |   471 ns (*) |  861 ns (+83%)
hash('\U0010ffff' * 1) |   465 ns (*) |  859 ns (+85%)
-----------------------+--------------+---------------
Total                  |  1.41 us (*) | 2.58 us (+83%)
-----------------------+--------------+---------------

-----------------------+--------------+---------------
Length 3               | original.txt |    patched.txt
-----------------------+--------------+---------------
hash('a' * 3)          |   465 ns (*) |  857 ns (+84%)
hash('\u20ac' * 3)     |   471 ns (*) |  859 ns (+82%)
hash('\U0010ffff' * 3) |   465 ns (*) |  862 ns (+86%)
-----------------------+--------------+---------------
Total                  |   1.4 us (*) | 2.58 us (+84%)
-----------------------+--------------+---------------

------------------------+--------------+---------------
Length 10               | original.txt |    patched.txt
------------------------+--------------+---------------
hash('a' * 10)          |   465 ns (*) |  900 ns (+94%)
hash('\u20ac' * 10)     |   467 ns (*) |  894 ns (+92%)
hash('\U0010ffff' * 10) |   471 ns (*) |  894 ns (+90%)
------------------------+--------------+---------------
Total                   |   1.4 us (*) | 2.69 us (+92%)
------------------------+--------------+---------------

------------------------+--------------+---------------
Length 20               | original.txt |    patched.txt
------------------------+--------------+---------------
hash('a' * 20)          |   465 ns (*) |  926 ns (+99%)
hash('\u20ac' * 20)     |   465 ns (*) | 928 ns (+100%)
hash('\U0010ffff' * 20) |   468 ns (*) |  919 ns (+96%)
------------------------+--------------+---------------
Total                   |   1.4 us (*) | 2.77 us (+98%)
------------------------+--------------+---------------

-------------------------+--------------+----------------
Length 100               | original.txt |     patched.txt
-------------------------+--------------+----------------
hash('a' * 100)          |   465 ns (*) |  1.4 us (+201%)
hash('\u20ac' * 100)     |   465 ns (*) | 1.39 us (+200%)
hash('\U0010ffff' * 100) |   464 ns (*) | 1.39 us (+199%)
-------------------------+--------------+----------------
Total                    |  1.39 us (*) | 4.18 us (+200%)
-------------------------+--------------+----------------

-----------------------------+--------------+-----------------
Length 10 ** 4               | original.txt |      patched.txt
-----------------------------+--------------+-----------------
hash('a' * 10 ** 4)          |   490 ns (*) | 35.7 us (+7192%)
hash('\u20ac' * 10 ** 4)     |   490 ns (*) | 35.7 us (+7186%)
hash('\U0010ffff' * 10 ** 4) |   495 ns (*) | 35.7 us (+7109%)
-----------------------------+--------------+-----------------
Total                        |  1.47 us (*) |  107 us (+7162%)
-----------------------------+--------------+-----------------

-----------------------------+--------------+---------------
Length 10 ** 8               | original.txt |    patched.txt
-----------------------------+--------------+---------------
hash('a' * 10 ** 8)          |   611 ms (*) |  413 ms (-32%)
hash('\u20ac' * 10 ** 8)     |   756 ms (*) |  392 ms (-48%)
hash('\U0010ffff' * 10 ** 8) |   913 ms (*) |  393 ms (-57%)
-----------------------------+--------------+---------------
Total                        | 2.28 sec (*) | 1.2 sec (-47%)
-----------------------------+--------------+---------------

---------------+--------------+----------------
Summary        | original.txt |     patched.txt
---------------+--------------+----------------
Length 1       |  1.41 us (*) |  2.58 us (+83%)
Length 3       |   1.4 us (*) |  2.58 us (+84%)
Length 10      |   1.4 us (*) |  2.69 us (+92%)
Length 20      |   1.4 us (*) |  2.77 us (+98%)
Length 100     |  1.39 us (*) | 4.18 us (+200%)
Length 10 ** 4 |  1.47 us (*) | 107 us (+7162%)
Length 10 ** 8 | 2.28 sec (*) |  1.2 sec (-47%)
---------------+--------------+----------------
Total          | 2.28 sec (*) |  1.2 sec (-47%)
---------------+--------------+----------------