[Bug rtl-optimization/43491] Unnecessary temporary for global register variable

[amker.cheng at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43491

--- Comment #4 from amker.cheng <amker.cheng at gmail dot com> 2011-12-21 03:44:03 UTC ---
This bug is even worse on mips.

The cause is ssa-pre eliminates global register variable when it is the RHS of
single assign statment, while following passes do not handle the const/register
attributes of the variable.
It can be handled in tree-ssa-pre.c without hurting true redundancy elimination
on global register variables.

So could somebody change the tag from rtl-optimization to tree-optimization?