[Bug middle-end/47383] ivopts miscompiles Pmode != ptr_mode

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47383

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> 2011-01-21 05:52:47 
UTC ---
Should ivopts use signed integer instead of unsigned integer
for index type if it is known to be negative?