commit f6b31bf0d082315103d2fb5fc8f2094be567bb63
author Yann Collet <cyan@fb.com> Sat Sep 30 10:35:55 2017 -0700
committer Yann Collet <cyan@fb.com> Sat Sep 30 10:35:55 2017 -0700
tree 49b07bb8e7912ce929b67bd25bc4b5e3e8f62c09
parent ceb868f4425a547bc5e08b6c80aaf4cc750fc9aa

fix #404

static analyzer `cppcheck` complains about a shift-by-32 on a 32 bits value,
which is an undefined behavior.
However, the flagged code path is never triggered in 32-bits mode,
(actually, it's not even generated if DCE kicks in),
the shift-by-32 is necessarily performed on a 64-bits value.

While it doesn't change anything regarding lz4 code generation, for both 32 and 64 bits mode,
(can be checked by md5sum on the generated binary),
the shift has been rewritten in a way which should please this static analyzer,
since it now pretends to shift by 16 on 32-bits cpu (note : it doesn't matter since the code will not even be generated in this case).

Note : this is a blind fix, the new code has not been tested with cppcheck, because cppcheck only works on Windows.
Other static analyzer, such as scan-build, do not trigger this false positive.