http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48812
--- Comment #2 from Matthieu CASTET 2011-04-29
19:18:43 UTC ---
> We also have to make sure the shift count does not get negative, which
we can't in this case. Thus (1U<<(b-2)) is not equivalent to
(1U<> (b-2))
But I agree it is not trivial opt
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48812
--- Comment #1 from Richard Guenther 2011-04-29
09:43:16 UTC ---
We do not exploit the fact that shifts bigger than the width of the type
are undefined (in fact we even try to preserve the fact that some CPUs
truncate the shift count when constan
