On Mon, Aug 12, 2019 at 3:56 PM Martin Liška <mli...@suse.cz> wrote: > > On 8/12/19 2:43 PM, Richard Biener wrote: > > On Mon, Aug 12, 2019 at 1:49 PM Martin Liška <mli...@suse.cz> wrote: > >> > >> On 8/12/19 1:40 PM, Richard Biener wrote: > >>> On Mon, Aug 12, 2019 at 1:19 PM Martin Liška <mli...@suse.cz> wrote: > >>>> > >>>> On 8/8/19 5:55 PM, Michael Matz wrote: > >>>>> Hi, > >>>>> > >>>>> On Mon, 10 Jun 2019, Martin Liska wrote: > >>>>> > >>>>>> 2019-07-24 Martin Liska <mli...@suse.cz> > >>>>>> > >>>>>> * fold-const.c (operand_equal_p): Rename to ... > >>>>>> (operand_compare::operand_equal_p): ... this. > >>>>>> (add_expr): Rename to ... > >>>>>> (operand_compare::hash_operand): ... this. > >>>>>> (operand_compare::operand_equal_valueize): Likewise. > >>>>>> (operand_compare::hash_operand_valueize): Likewise. > >>>>>> * fold-const.h (operand_equal_p): Set default > >>>>>> value for last argument. > >>>>>> (class operand_compare): New. > >>>>> > >>>>> Hmpf. A class without any data? That doesn't sound like a good design. > >>>> > >>>> Yes, the base class (current operand_equal_p) does not have a data. > >>>> But the ICF derive class has a data and e.g. > >>>> func_checker::operand_equal_valueize > >>>> will use m_label_bb_map.get (t1). Which are member data of class > >>>> func_checker. > >>>> > >>>>> You seem to need it only to have the possibility of virtual functions, > >>>>> i.e. fancy callbacks. AFAICS you only have one derived class, i.e. a > >>>>> simple distinction of two cases. What do you think about encoding the > >>>>> additional new (ICF) case in the (existing) 'flags' argument to > >>>>> operand_equal_p (and in case the ICF flag is set simply call the > >>>>> "callback" directly)? > >>>> > >>>> That's possible. I can add two more callbacks to the operand_equal_p > >>>> function > >>>> (hash_operand_valueize and operand_equal_valueize). > >>>> > >>>> Is Richi also supporting this approach? > >>> > >>> I still see no value in the abstraction since you invoke none of the > >>> (virtual) methods from the base class operand_equal_p. > >> > >> I call operand_equal_valueize (and hash_operand) from operand_equal_p. > >> These are then used in IPA ICF (patch 6/9). > > > > Ugh. I see you call that after > > > > if (TREE_CODE (arg0) != TREE_CODE (arg1)) > > { > > ... > > } > > else > > return false; > > } > > > > and also after > > > > /* Check equality of integer constants before bailing out due to > > precision differences. */ > > if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) > > > > which means for arg0 == SSA_NAME and arg1 == INTEGER_CST you return false > > instead of valueizing arg0 to the possibly same or same "lose" value > > and returning true. > > Yes. ICF does not allow to have anything where TREE_CODEs do not match. > > > > > Also > > > > + int val = operand_equal_valueize (arg0, arg1, flags); > > + if (val == 1) > > + return 1; > > + if (val == 0) > > + return 0; > > > > suggests that you pass in arbirtrary trees for "valueization" but it > > isn't actually > > valueization that is performed but instead it should do an alternate > > comparison > > of arg0 and arg1 with valueization. Why's this done this way instead of > > sth like > > > > if (TREE_CODE (arg0) == SSA_NAME) > > arg0 = operand_equal_valueize (arg0, flags); > > if (TREE_CODE (arg1) == SSA_NAME) > > arg1 = operand_equal_valueize (arg1, flags); > > Because I want to be given a pair of trees about which the function > operand_equal_valueize returns match/no-match/dunno. > > > > > and why's this done with virtual functions rather than a callback that we > > can > > cheaply check for NULLness in the default implementation? > > I can transform it into a hook. But as mentioned I'll need two hooks. > > > > > So - what does ICF want to make "equal" that isn't equal normally and how's > > that "valueization"? > > E.g. for a FUNCTION_DECL, ICF always return true because it can only calls > the operand_equal_p after callgraph is compared. Similarly for LABEL_DECLs, > we have a map (m_label_bb_map). Please take a look at patch 6/9 in this > series.
Hmm, ok, so you basically replace recursive calls to operand_equal_p with operand_equal_valueize (t1, t2, 0) || operand_equal_p (t1, t2, 0) no? But the same could be achieved by actually making t1 and t2 equal according to operand_equal_p rules via the valueization hook? So replace FUNCTION_DECLs with their prevailing ones, LABEL_DECLs with theirs, etc. As given your abstraction is quite awkward to use, say, from value-numbering which knows how to "valueize" a single tree but doesn't compare things. To make it work for your case you'd valueize not only SSA names but also all DECL_P I guess. After all your operand_equal_valueize only does something for "leafs" but is called for all intermediate expressions as well. Richard. > Thanks, > Martin > > > > > Thanks, > > Richard. > > > >> Martin > >> > >>> > >>> Richard. > >>> > >>>> Thanks, > >>>> Martin > >>>> > >>>>> IMHO that would also make the logic within > >>>>> operand_equal_p clearer, because you don't have to think about all the > >>>>> potential callback functions that might be called. > >>>>> > >>>>> > >>>>> Ciao, > >>>>> Michael. > >>>>> > >>>> > >> >