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From: "steven at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/38474] slow compilation at -O0 (callgraph optimization, inline heuristics, expand ) Date: Mon, 15 Dec 2008 21:29:00 -0000 [thread overview] Message-ID: <20081215212740.28755.qmail@sourceware.org> (raw) In-Reply-To: <bug-38474-6642@http.gcc.gnu.org/bugzilla/> ------- Comment #13 from steven at gcc dot gnu dot org 2008-12-15 21:27 ------- OK, to elaborate: I'm playing with this test case on ia64-linux, and I reduced the test case by some 8000 lines to make it compilable at all. With this 8000 lines less, it actually spends more time for me in "expand", in the function "find_temp_slot_from_address (rtx x)". It spends all of its time... for (i = max_slot_level (); i >= 0; i--) for (p = *temp_slots_at_level (i); p; p = p->next) { if (XEXP (p->slot, 0) == x || p->address == x || (GET_CODE (x) == PLUS && XEXP (x, 0) == virtual_stack_vars_rtx && GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) >= p->base_offset && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)) return p; else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST) for (next = p->address; next; next = XEXP (next, 1)) if (XEXP (next, 0) == x) /* ...here in this loop... */ return p; in the "for (next = p->address; ...)" loop. This list in p->address is actually several thousand items long and it is traversed many times: traversals ~ max_slot_level()*temp_slots_at_level(i)*list length of p->address which is, at best, cubic behavior. -- steven at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed|2008-12-10 15:39:38 |2008-12-15 21:27:40 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38474
next prev parent reply other threads:[~2008-12-15 21:29 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-12-10 15:26 [Bug middle-end/38474] New: slow compilation at -O0 (callgraph optimization, inline heuristics, ggc " jv244 at cam dot ac dot uk 2008-12-10 15:27 ` [Bug middle-end/38474] " jv244 at cam dot ac dot uk 2008-12-10 15:41 ` [Bug middle-end/38474] slow compilation at -O0 (callgraph optimization, inline heuristics, " rguenth at gcc dot gnu dot org 2008-12-10 16:14 ` jv244 at cam dot ac dot uk 2008-12-10 16:58 ` rguenth at gcc dot gnu dot org 2008-12-10 22:35 ` jv244 at cam dot ac dot uk 2008-12-10 22:49 ` rguenth at gcc dot gnu dot org 2008-12-10 22:58 ` jv244 at cam dot ac dot uk 2008-12-11 8:28 ` jv244 at cam dot ac dot uk 2008-12-11 11:35 ` rguenth at gcc dot gnu dot org 2008-12-11 12:04 ` jv244 at cam dot ac dot uk 2008-12-15 19:39 ` jv244 at cam dot ac dot uk 2008-12-15 21:19 ` steven at gcc dot gnu dot org 2008-12-15 21:29 ` steven at gcc dot gnu dot org [this message] 2008-12-15 21:54 ` steven at gcc dot gnu dot org 2008-12-15 21:56 ` steven at gcc dot gnu dot org 2008-12-15 21:57 ` steven at gcc dot gnu dot org 2008-12-16 7:52 ` jv244 at cam dot ac dot uk 2008-12-16 11:59 ` jv244 at cam dot ac dot uk 2008-12-16 12:46 ` steven at gcc dot gnu dot org 2008-12-16 12:48 ` jv244 at cam dot ac dot uk 2008-12-16 12:50 ` jv244 at cam dot ac dot uk 2008-12-16 13:43 ` steven at gcc dot gnu dot org 2008-12-16 14:19 ` jv244 at cam dot ac dot uk 2008-12-16 14:21 ` jv244 at cam dot ac dot uk 2008-12-16 16:19 ` jv244 at cam dot ac dot uk 2008-12-16 16:28 ` steven at gcc dot gnu dot org 2008-12-16 16:31 ` jv244 at cam dot ac dot uk 2008-12-16 19:35 ` [Bug middle-end/38474] [4.3/4.4 Regression] " pinskia at gcc dot gnu dot org 2008-12-16 20:32 ` jv244 at cam dot ac dot uk 2008-12-17 6:52 ` jv244 at cam dot ac dot uk 2008-12-17 7:03 ` steven at gcc dot gnu dot org 2008-12-17 8:37 ` jv244 at cam dot ac dot uk 2008-12-17 12:59 ` jv244 at cam dot ac dot uk 2008-12-17 19:42 ` steven at gcc dot gnu dot org 2008-12-20 9:00 ` jv244 at cam dot ac dot uk 2008-12-20 9:56 ` steven at gcc dot gnu dot org 2008-12-20 11:33 ` [Bug middle-end/38474] [Meta] " jv244 at cam dot ac dot uk 2008-12-20 15:51 ` steven at gcc dot gnu dot org 2009-01-24 10:27 ` rguenth at gcc dot gnu dot org 2009-08-04 12:45 ` rguenth at gcc dot gnu dot org 2009-11-27 8:52 ` jv244 at cam dot ac dot uk 2009-11-27 9:00 ` jv244 at cam dot ac dot uk 2009-11-27 10:50 ` rguenth at gcc dot gnu dot org 2009-12-03 13:37 ` matz at gcc dot gnu dot org 2009-12-03 17:48 ` jv244 at cam dot ac dot uk 2009-12-03 21:05 ` matz at gcc dot gnu dot org 2009-12-08 13:56 ` matz at gcc dot gnu dot org 2010-05-22 18:33 ` rguenth at gcc dot gnu dot org 2010-05-23 6:31 ` jv244 at cam dot ac dot uk 2010-05-23 20:09 ` rguenth at gcc dot gnu dot org 2010-05-23 21:03 ` [Bug middle-end/38474] slow compilation at -O0 due to expand's temp slot goo steven at gcc dot gnu dot org
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