Re: Question on ipa_ref->referring and ipa_ref->stmt on all_late_ipa_passes
On Mon, 14 Feb 2022 at 10:57, Jan Hubicka wrote: > > Hi, > > > > I would like to use ipa_ref in the PASS_LIST all_late_ipa_passes to query > > the statement (ref->stmt) of where a global variable is used. However, I > am > > having some problems achieving this. > > > > What I do is: > > > > 1. Check that ipa_ref->referring has a body and is not inlined. > > 2. get_body > > 3. try to print out the gimple statement using print_gimple_stmt > > (dump_file, ref->stmt, 0, TDF_NONE). > > > > This all seems correct to me, but I have been receiving errors that print > > is trying to print a tree with an incorrect TREE_CODE. I am assuming here > > that ref->stmt is not updated after all_regular_ipa_passes, much like how > > when looking at cgraph_edge the call statement is also not updated. Can > > someone please tell me if this is indeed the case or what is happening > here? > > Yes, while body materialization we keep cgraph edges up to date but we > do not keep references. We probably should remove them earlier. > Keeping them up to date would need relatively some work. We do so for > calls since they hold important information (i.e. where to redirect the > call). For references we don't have such machinery in place (even though > I was thinking implementing it). Main difficulty is that inlining also > performs statement folding that moves referneces around statements quite > freely > Hi Honza, just a bit of clarification here, when you are saying that references are not updated do you mean just ipa_ref->stmt or do you also include other things like ipa_ref->referring, ipa_ref->use? Thanks! > > > > Also, while I think that the gimple statements might not be maintained, I > > see that ipa_ref is still used in the ipa_pta pass during > > all_late_ipa_passes. I see that ipa_ref->referring and ipa_ref->stmt are > > not used. Instead the tree of the referred is obtained in the following > > way: ref->referred->decl. I am assuming that it would be possible to use > > ref->referred->decl and search for this tree everywhere in referring to > > find the uses. Can someone confirm this? > > I will check what ipa-pta uses here. I suppose it works since you still > have all references from the pre-IPA-transform stage, so it is > consistent... > > Honza > > > > Thanks! > > -Erick >
Re: Question on ipa_ref->referring and ipa_ref->stmt on all_late_ipa_passes
> Hi, > > I would like to use ipa_ref in the PASS_LIST all_late_ipa_passes to query > the statement (ref->stmt) of where a global variable is used. However, I am > having some problems achieving this. > > What I do is: > > 1. Check that ipa_ref->referring has a body and is not inlined. > 2. get_body > 3. try to print out the gimple statement using print_gimple_stmt > (dump_file, ref->stmt, 0, TDF_NONE). > > This all seems correct to me, but I have been receiving errors that print > is trying to print a tree with an incorrect TREE_CODE. I am assuming here > that ref->stmt is not updated after all_regular_ipa_passes, much like how > when looking at cgraph_edge the call statement is also not updated. Can > someone please tell me if this is indeed the case or what is happening here? Yes, while body materialization we keep cgraph edges up to date but we do not keep references. We probably should remove them earlier. Keeping them up to date would need relatively some work. We do so for calls since they hold important information (i.e. where to redirect the call). For references we don't have such machinery in place (even though I was thinking implementing it). Main difficulty is that inlining also performs statement folding that moves referneces around statements quite freely > > Also, while I think that the gimple statements might not be maintained, I > see that ipa_ref is still used in the ipa_pta pass during > all_late_ipa_passes. I see that ipa_ref->referring and ipa_ref->stmt are > not used. Instead the tree of the referred is obtained in the following > way: ref->referred->decl. I am assuming that it would be possible to use > ref->referred->decl and search for this tree everywhere in referring to > find the uses. Can someone confirm this? I will check what ipa-pta uses here. I suppose it works since you still have all references from the pre-IPA-transform stage, so it is consistent... Honza > > Thanks! > -Erick
Question on ipa_ref->referring and ipa_ref->stmt on all_late_ipa_passes
Hi, I would like to use ipa_ref in the PASS_LIST all_late_ipa_passes to query the statement (ref->stmt) of where a global variable is used. However, I am having some problems achieving this. What I do is: 1. Check that ipa_ref->referring has a body and is not inlined. 2. get_body 3. try to print out the gimple statement using print_gimple_stmt (dump_file, ref->stmt, 0, TDF_NONE). This all seems correct to me, but I have been receiving errors that print is trying to print a tree with an incorrect TREE_CODE. I am assuming here that ref->stmt is not updated after all_regular_ipa_passes, much like how when looking at cgraph_edge the call statement is also not updated. Can someone please tell me if this is indeed the case or what is happening here? Also, while I think that the gimple statements might not be maintained, I see that ipa_ref is still used in the ipa_pta pass during all_late_ipa_passes. I see that ipa_ref->referring and ipa_ref->stmt are not used. Instead the tree of the referred is obtained in the following way: ref->referred->decl. I am assuming that it would be possible to use ref->referred->decl and search for this tree everywhere in referring to find the uses. Can someone confirm this? Thanks! -Erick
