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[Bug middle-end/18927] O(n^2) compile time with -O0 (n= number of basic blocks) in local alloc
- From: "steven at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 11 Dec 2004 13:14:44 -0000
- Subject: [Bug middle-end/18927] O(n^2) compile time with -O0 (n= number of basic blocks) in local alloc
- References: <20041210154259.18927.heinrich.brand@fujitsu-siemens.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From steven at gcc dot gnu dot org 2004-12-11 13:14 -------
Ah, but it's not *global* alloc, it is *local* alloc! From your scripts:
local alloc : 0.16 (59%) usr 0.00 ( 0%) sys 0.00 ( 0%) wall
local alloc : 0.63 (72%) usr 0.00 ( 0%) sys 0.50 (50%) wall
local alloc : 2.69 (85%) usr 0.00 ( 0%) sys 2.50 (83%) wall
local alloc : 10.89 (92%) usr 0.02 (15%) sys 11.00 (92%) wall
local alloc : 58.39 (96%) usr 0.04 (14%) sys 58.50 (95%) wall
(last 3 omitted for obvious reasons)
--
What |Removed |Added
----------------------------------------------------------------------------
Summary|O(n^2) compile time with -O0|O(n^2) compile time with -O0
|(n= number of basic blocks) |(n= number of basic blocks)
|in global alloc |in local alloc
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18927