------- Additional Comments From dnovillo at gcc dot gnu dot org 2005-03-02 15:28 -------
Pasting IRC dialogue to avoid forgetting what this was all about: <stevenb> dnovillo: i had a patch to make CCP look in initializers for structures, but rth and you rejected it, claiming it should not be done in CCP but in fold. <dnovillo> stevenb: rth rejected it, actually. <stevenb> oh whatever. someone did. <dnovillo> stevenb: i remember it having some issues, but don't remember what those were. <stevenb> dnovillo: rth said it should not be in ccp, and be more general <dnovillo> stevenb: in fold? that sounds more like a job for get_default_value. <stevenb> dnovillo: i just took code from expr.c but apparently just replacing that was not good enough <DannyB> It is a job <dnovillo> anyway, what became of that? <DannyB> for get_default_value <stevenb> dnovillo: dropped on the floor until 4.1 <stevenb> dnovillo: and now not interesting anymore <stevenb> dnovillo: the primary motivation was IS_EXPR_CODE_CLASS <dnovillo> stevenb: ok. do you have your latest draft? <stevenb> dnovillo: but that's done without strchr now <stevenb> dnovillo: probably floating somewhere in the gcc-patches archives <dnovillo> stevenb: any date/subject that may help me dig it out? i'll put it in my pile. <vagabon> dnovillo: RP done.... <stevenb> dnovillo: there is a PR for it that is already assigned to you <dnovillo> stevenb: you're joking. <dnovillo> really? <vagabon> :) <dnovillo> sigh <vagabon> now 2 PR <stevenb> dnovillo: i am not a funny guy. i never make jokes about it ;) <dnovillo> stevenb: is this the one you're thinking about? http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14841 <gccbot> gcc bug #14841: [tree-ssa] const_array[CST] is not folded Product: gcc, Component: tree-optimization, Severity: enhancement, Assigned to: [EMAIL PROTECTED], Status: ASSIGNED <stevenb> that sounds familiar <stevenb> dnovillo: yes that is the one i was thinking of <stevenb> dnovillo: there was a better patch that did structs also <stevenb> dnovillo: but i think i never posted that because it causes quadratic behavior <stevenb> dnovillo: the problem being that constructors are not sorted <stevenb> dnovillo: the patch from that PR also helps the DFA code in insn-attrtab.c btw <DannyB> Ah yes, now i remember this whole discussion <dnovillo> stevenb: what's that about constructors? <stevenb> dnovillo: the problem with initializers for structs is that they are represented as constructors, but they are not sorted in any way <stevenb> dnovillo: so if you go look for what some field is initialized with, you have to go through the whole constructor <dnovillo> ah <stevenb> dnovillo: and if you have to look for a field initializer for all fields, that is quadratic -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20284
