------- Comment #14 from rguenther at suse dot de 2007-11-07 15:05 ------- Subject: Re: [4.3 Regression] ICE in ssa_operand_alloc, at tree-ssa-operands.c:487 with -O3
On Wed, 7 Nov 2007, dnovillo at google dot com wrote: > Subject: Re: [4.3 Regression] ICE in ssa_operand_alloc, at > tree-ssa-operands.c:487 with -O3 > > On 7 Nov 2007 13:52:29 -0000, amacleod at redhat dot com > <[EMAIL PROTECTED]> wrote: > > > There is also an issue with partitioning, but it would then hide what I > > think is an important issue. > > > > Partitioning's problem is that it counts the number of items in the > > alias set and just uses that. There is only one entry for an entire SFT > > list, so it misses the other 819 in this particular list. The difficulty > > is determining how many of those SFTs are actually going to be > > relevant. Ideally, partitioning would share code with VOP processing so > > it can see exactly how many VOPs would be generated by each MEM. > > Agreed. The partitioner heuristics got severely skewed when we > switched alias sets to only contain the first SFT in the pointed-to > structure. But that should be a relatively simple fix. It actually contains all pointed-to SFTs. But yes, we should be able to fix this by conservatively counting VOPs (that is, rather overestimate). I plan to look at the heuristics as soon as we settled on a fix for the wrong-code PR33870. Richard. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31976