[Bug middle-end/37780] Conditional expression with __builtin_clz() should be optimized out

[amker.cheng at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37780

--- Comment #2 from amker.cheng <amker.cheng at gmail dot com> 2012-03-20 07:58:09 UTC ---
the special case could be easily detected when gimplifying.
but actually I am not sure whether it can be done even in middle end, since the
middle end should not depend on any target information, like
CLZ_DEFINED_VALUE_AT_ZERO, right?