I have been trying to cleanup the location where the persistent ipa
information is stored.
The original way that I did this was that I had a field in the var_ann
structure that pointed to the ipa_information.
Now that danny has reorganized the decls, the plan was to just add a
field to the function_decl.
Danny has suggested that if I was going to add such a field, it should
be a pointer to the cgraph_node and then store the persistent ipa
information there.
I noticed that if I did this, there should be a lot of stuff that could
fall away. There would be no need to have the hash table that points
from function_decls to cgraph nodes as well as there was no need for the
master_clone field since the cgraph node that the decl pointed to would
be just this good. All of this sounds great... smaller, faster.
This has not gone as easy as I had hoped. Danny found the first
stumbling block yesterday that the c decl merging needed to be enhanced.
The second bug appears to be harder. In c++, there really can be
multiple function_decls with the same uid.
The kludge to handle them is documented in cp/name-lookup.c around line
670 and one test case to generate them is in
gcc/testsuite/g++.dg/opt/inline2.C.
There are several ways to go about fixing this: One is to just abandon
my fix and let others (such as the code sourcery people deal with it
when they go to build a real symbol table.)
It seems like a better way is to build a table of merges that need to be
done and find some place after the c++ front end is finished but before
the cgraph gets built and do one scan of the code and replace all of the
offending decls.
Does such a location exist?
Is this the correct plan?
Kenny
