------- Additional Comments From pinskia at gcc dot gnu dot org 2005-08-11
18:23 -------
What is happening is that out of SSA is doing almost no coalescing at all, it
only coalesces SSA_NAME
which have the same decl.
To me, it looks like copyrename is missing an opportunity to rename a SSANAME:
# D.15690_3 = PHI <0(3), mult_41(12), D.15690_13(14), 0(0), mult_55(11),
mult_28(13)>;
well it turns out this might be harder to do than orginally I had thought as
one of the arguments to the
PHI is does not have a SSA_NAME whos decl is mult.
This problem is understood but hard to get right.
I will try to get a small example for this issue, note this is also an issue in
4.0.0 too.
--
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |minor
Summary|out of ssa does not delete |out of ssa does coalesce
|single def single use |some variables
|variable |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23335
