Comment 1 for bug 1589268

5.1 release notes include

"""
We have released PyPy 5.1, about a month after PyPy 5.0.
We encourage all users of PyPy to update to this version. Apart from the usual
bug fixes, there is an ongoing effort to improve the warmup time and memory
usage of JIT-related metadata, and we now fully support the IBM s390x
architecture.
"""

+=========================
+What's new in PyPy 5.1
+=========================
+
+.. this is a revision shortly after release-5.0
+.. startrev: b238b48f9138
+
+.. branch: s390x-backend
+
+The jit compiler backend implementation for the s390x architecutre.
+The backend manages 64-bit values in the literal pool of the assembly instead of loading them as immediates.
+It includes a simplification for the operation 'zero_array'. Start and length parameters are bytes instead of
size.
+
+.. branch: remove-py-log
+
+Replace py.log with something simpler, which should speed up logging
+
+.. branch: where_1_arg
+
+Implemented numpy.where for 1 argument (thanks sergem)
+
+.. branch: fix_indexing_by_numpy_int
+
+Implement yet another strange numpy indexing compatibility; indexing by a scalar
+returns a scalar
+
+.. branch: fix_transpose_for_list_v3
+
+Allow arguments to transpose to be sequences
+
+.. branch: jit-leaner-frontend
+
+Improve the tracing speed in the frontend as well as heapcache by using a more compact representation
+of traces
+
+.. branch: win32-lib-name
+
+.. branch: remove-frame-forcing-in-executioncontext
+
+.. branch: rposix-for-3
+
+Wrap more POSIX functions in `rpython.rlib.rposix`.
+
+.. branch: cleanup-history-rewriting
+
+A local clean-up in the JIT front-end.
+
+.. branch: jit-constptr-2
+
+Remove the forced minor collection that occurs when rewriting the
+assembler at the start of the JIT backend. This is done by emitting
+the ConstPtrs in a separate table, and loading from the table. It
+gives improved warm-up time and memory usage, and also removes
+annoying special-purpose code for pinned pointers.
+
+.. branch: fix-jitlog
+
+.. branch: cleanup-includes
+
+Remove old uneeded numpy headers, what is left is only for testing. Also
+generate pypy_numpy.h which exposes functions to directly use micronumpy
+ndarray and ufuncs