On Thu, Nov 9, 2017 at 4:24 PM, Andrew MacLeod <amacl...@redhat.com> wrote: > On 11/09/2017 10:16 AM, Richard Biener wrote: >> >> On Thu, Nov 9, 2017 at 3:44 PM, Andrew MacLeod <amacl...@redhat.com> >> wrote: >>> >>> I'm a little confused. In gimple I need to do a comparison between 2 >>> values, and I create a boolean_type_node result. >>> I then combine it with an existing condition, but fortran is crapping out >>> on >>> me because the boolean_type I created is not >>> compatible with the boolean type is has already created for a different >>> condition: >>> >>> Its not exactly this situation, but the idea is similar: >>> >>> _65 = _37 != 0; <<-- in the IL >>> _77 = _34 != 0; <<-- Im creating this >>> >>> and something like >>> >>> (_65 != _77) >>> >>> Craps out on me because the types are incompatible. >>> >>> The expression created by fortran assigned to _65 is of type: >>> logical(kind=4) >>> and mine, _77 created with boolean_type_node, is logical(kind=1) >>> >>> I was under the impression that using boolean_type_node would give me the >>> right kind of boolean for that language, but apparently I was mistaken. >>> >>> If I don't have the context of the type of _65, how am I suppose to get >>> the >>> right boolean type for _77 when I create it? I don't want to cast it to >>> the >>> right logical kind, Id like to just get it right. I haven't stumbled >>> across any hooks or other obvious thing... >>> >>> I feel like I am missing something obvious... :-P >> >> You should already know the boolean type from the existing comparison in >> the IL. >> That is, you shouldn't generate conditions out of thin air, do you? That >> is, >> there isn't a "single" boolean type a random hook would tell you. >> >> Richard. > > Yeah, I do actually generate them from thin air :-) That why I said it > wasnt exactly that situation. All I have is 2 arbitrary things that are > being compared, and then eventually I sometimes end up combining it with an > existing boolean. I dont know in advance that I will need to combine it. I > chose boolean_type_node because I thought it was the default.
Sure - you can use boolean_type_node. Then when combining you need to convert to a common boolean type (choose any). Eventually forwprop will retroactively "fix" your (or the other) generated comparison to produce the correct type in the first place. > I presume fortran is using SImode because it works better, or there is some > other subtle difference? Fortran has boolean types of each size -- logical(1) to logical(16). > so even if I wasn't eventually combining it with a > logical, and I was using the default QImode, I would generate less than > ideal code? Is there not a way for the optimizers to pick the preferred > type? The preferred type depends on the context and should almost always be boolean_type_node _unless_ the bool(s) you are working with are loaded from / stored to memory where of course the size of the bool matters. Richard. > > Andrew > >
