The randomly generated offset+width may exceeds 32, which causes
a left shift operation with 32-offset-width. As an unsigned number
that is greater than 32 and causes undefined behavior. When the
test is compiled without -mavx it is still OK. However when
the test is compiled with -mavx, the undefined behavior causes
wrong results and test failure.
This patch adjusts width so that offset+width<=32 always.
Yaxun (Sam) Liu
Maneesh Gupta
Aaron Enye Shi