public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "falk at debian dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/31911]  New: Short function (md4) takes very long to compile
Date: Sun, 13 May 2007 12:48:00 -0000	[thread overview]
Message-ID: <bug-31911-2744@http.gcc.gnu.org/bugzilla/> (raw)

The attached code (a md4 function, about 100 lines) takes many minutes
(apparently >100) to compile with gcc mainline 4.3 at -O3. At -O2, or with gcc
4.2, it takes below 1 second. 4.3.0 20070411 is OK, too. Memory requirement
stays very low.

The top of a profile with mainline looks like this:

%        symbol name
14.8255  iterative_hash_expr
14.5251  bitmap_find_leader
13.8068  phi_translate
 7.3317  iterative_hash
 6.5265  get_value_handle
 5.3315  htab_find_slot_with_hash
 5.0914  iterative_hash_pointer
 3.8050  iterative_hash_hashval_t
 3.4260  bitmap_set_contains_value
 2.3798  is_gimple_min_invariant
 2.2232  iterative_hash_host_wide_int
 2.0325  tree_operand_length
 1.8615  translate_vuses_through_block
 1.7766  bitmap_bit_p
 1.6062  find_leader_in_sets
 1.5111  expression_for_id
 1.3981  vn_compute
 1.2290  tree_operand_length
 1.0592  expr_pred_trans_eq


-- 
           Summary: Short function (md4) takes very long to compile
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: falk at debian dot org
 GCC build triplet: alphaev68-unknown-linux-gnu
  GCC host triplet: alphaev68-unknown-linux-gnu
GCC target triplet: alphaev68-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31911


             reply	other threads:[~2007-05-13 12:48 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-13 12:48 falk at debian dot org [this message]
2007-05-13 12:49 ` [Bug tree-optimization/31911] " falk at debian dot org
2007-05-13 13:12 ` rguenth at gcc dot gnu dot org
2007-05-13 13:15 ` [Bug tree-optimization/31911] [4.3 Regression] " rguenth at gcc dot gnu dot org
2007-05-13 15:01 ` dberlin at gcc dot gnu dot org
2007-05-13 21:52 ` dberlin at gcc dot gnu dot org
2007-05-13 21:52 ` dberlin at gcc dot gnu dot org

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=bug-31911-2744@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).