[Bug libstdc++/21796] New: (v7-branch) std::search not using std::find

[Bug libstdc++/21796] New: (v7-branch) std::search not using std::find

[pcarlini at suse dot de]

When merging to release branches the work on <algorithm> we have to resolve
this issue: the new unified std::search doesn't exploit std::find, and a small
performance regression is possible, in theory: at least benchmark. FWIW, in
mainline, we have an inconsistency instead: only the version not taking a
predicate does use std::find.

-- 
           Summary: (v7-branch) std::search not using std::find
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: pcarlini at suse dot de
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[chris at bubblescope dot net]

------- Additional Comments From chris at bubblescope dot net  2005-06-04 12:07 -------
This is being held up by PR20408, Unnecessary code generated for empty structs, as we'd have to pass 
both the item to find and the comparitor (which is often an empty class) to std::find_if

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |20408


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-06-04 15:16 -------
(In reply to comment #1)
> This is being held up by PR20408, Unnecessary code generated for empty structs, as we'd have to 
> pass both the item to find and the comparitor (which is often an empty class) to std::find_if
Why do you care about one instruction, only on stack argument passing targets?
Really there is no good reason to block one improvement for another which is most likely not going to 
be fixed in a long time.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-06-04 15:16:04
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[pcarlini at suse dot de]

------- Additional Comments From pcarlini at suse dot de  2005-06-04 18:00 -------
There is some truth in what Andrew and Chris are saying, and myself ;) : we
have quite a few improvements to merge to mainline and other in progress in
v7. Maybe, as an intermediate step, we will end up taking care of this
issue separately from 20408.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[chris at bubblescope dot net]

------- Additional Comments From chris at bubblescope dot net  2005-06-18 22:18 -------
Actually, *slaps forehead*, the problem of empty structs can just be avoided
using EBO :) I'll knock up a patch doing just that :)

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[pcarlini at suse dot de]

------- Additional Comments From pcarlini at suse dot de  2005-06-18 22:21 -------
Ah! And in that case the solution promises to be also very clean! Remember to
post first a simple example, as usual.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-06-29 19:21 -------
Subject: Bug 21796

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	libstdcxx_so_7-branch
Changes by:	paolo@gcc.gnu.org	2005-06-29 19:20:49

Modified files:
	libstdc++-v3/include/bits: predefined_ops.h stl_algo.h 
	libstdc++-v3/testsuite/25_algorithms/search: 1.cc check_type.cc 
	libstdc++-v3/src: string-inst.cc 

Log message:
	2005-06-29  Chris Jefferson <chris@bubblescope.net>
	
	PR libstdc++/21796
	* include/bits/predefined_ops.h (__bind2nd, bind2nd): New.
	* include/bits/stl_algo.h (search): Delegate to specializations.
	(__search(,,,,,forward_iterator_tag): Tidy up original version of
	std::search, add calls to find_if.
	(__search(,,,,,random_access_iterator_tag): Add new random access
	specialization.
	* testsuite/25_algorithms/search/1.cc: Add new test.
	* testsuite/25_algorithms/search/check_type.cc: Improve and extend
	tests.
	
	2005-06-29  Paolo Carlini  <pcarlini@suse.de>
	
	* src/string-inst.cc: Add explicit instantiations of __search and
	__find_if.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/predefined_ops.h.diff?cvsroot=gcc&only_with_tag=libstdcxx_so_7-branch&r1=1.1.2.2&r2=1.1.2.3
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/include/bits/stl_algo.h.diff?cvsroot=gcc&only_with_tag=libstdcxx_so_7-branch&r1=1.47.6.13&r2=1.47.6.14
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/25_algorithms/search/1.cc.diff?cvsroot=gcc&only_with_tag=libstdcxx_so_7-branch&r1=1.1.2.2&r2=1.1.2.3
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/testsuite/25_algorithms/search/check_type.cc.diff?cvsroot=gcc&only_with_tag=libstdcxx_so_7-branch&r1=1.1.2.1&r2=1.1.2.2
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/libstdc++-v3/src/string-inst.cc.diff?cvsroot=gcc&only_with_tag=libstdcxx_so_7-branch&r1=1.31.8.2&r2=1.31.8.3



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796

[Bug libstdc++/21796] (v7-branch) std::search not using std::find

[pcarlini at suse dot de]

------- Additional Comments From pcarlini at suse dot de  2005-06-29 19:21 -------
Fixed.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21796