Re: optimization/10160: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"

Re: optimization/10160: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"

[Vladimir Makarov]

The following reply was made to PR optimization/10160; it has been noted by GNATS.

From: Vladimir Makarov <vmakarov@redhat.com>
To: ebotcazou@gcc.gnu.org, china@thewrittenword.com,
	gcc-bugs@gcc.gnu.org, gcc-prs@gcc.gnu.org, vmakarov@gcc.gnu.org,
	gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: optimization/10160: [3.3/3.4 regression][SPARC] compile time 
 regression; inordinate time spent in "scheduling"
Date: Wed, 16 Apr 2003 13:39:59 -0400

 ebotcazou@gcc.gnu.org wrote:
 > 
 > Synopsis: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"
 > 
 > Responsible-Changed-From-To: vmakarov->ebotcazou
 > Responsible-Changed-By: ebotcazou
 > Responsible-Changed-When: Wed Apr 16 13:14:39 2003
 > Responsible-Changed-Why:
 >     Hum... I don't think that the scheduler is to be blamed here,
 >     rather the tree inliner: cutting the inlining limit by 10
 >     (-finline-limit=60) brings the compile time on par with that
 >     of the 3.2.x branch.
 > 
 >     The new logic of the tree inliner is not exactly adapted to this testcase.
 > 
 > http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10160
 
 You are absolutely right.  I was afraid that it is because of the first
 cycle multipass insn scheduling.  So I switched it off and got the same
 result.  So this is not because of the recent insn scheduling changes. 
 Simply insn scheduling (even simplest heuristic list one) is O(n*2)
 algorithm.  So it may behave very nasty when the input is big.  There
 are some heuristics constraining number of dependencies but they do not
 help in this case.  Even without insn scheduling compilation of this
 file takes 12 minutes on my sparc computer.
 
 Vlad

Re: optimization/10160: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"

[ebotcazou]

Synopsis: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"

Responsible-Changed-From-To: vmakarov->ebotcazou
Responsible-Changed-By: ebotcazou
Responsible-Changed-When: Wed Apr 16 13:14:39 2003
Responsible-Changed-Why:
    Hum... I don't think that the scheduler is to be blamed here,
    rather the tree inliner: cutting the inlining limit by 10
    (-finline-limit=60) brings the compile time on par with that
    of the 3.2.x branch.
    
    The new logic of the tree inliner is not exactly adapted to this testcase.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10160

Re: optimization/10160: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"

[ebotcazou]

Synopsis: [3.3/3.4 regression][SPARC] compile time regression; inordinate time spent in "scheduling"

Responsible-Changed-From-To: ebotcazou->vmakarov
Responsible-Changed-By: ebotcazou
Responsible-Changed-When: Mon Apr 14 08:26:33 2003
Responsible-Changed-Why:
    No, I don't know the first thing about the DFA scheduler.
    David S. Miller wrote the Sparc descriptions but he is busy
    elsewhere so I'm redirecting the PR to Vladimir directly.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10160

Re: optimization/10160: [3.3/3.4 regression[[SPARC] compile time regression; inordinate time spent in "scheduling"

[steven]

Old Synopsis: [SPARC] inordinate time spent in "scheduling"
New Synopsis: [3.3/3.4 regression[[SPARC] compile time regression; inordinate time spent in "scheduling"

Responsible-Changed-From-To: unassigned->ebotcazou
Responsible-Changed-By: steven
Responsible-Changed-When: Mon Apr 14 07:18:19 2003
Responsible-Changed-Why:
    Regression from 3.2.2
    
    Looks like food for you, Eric.
State-Changed-From-To: feedback->analyzed
State-Changed-By: steven
State-Changed-When: Mon Apr 14 07:18:19 2003
State-Changed-Why:
    Confirmed regression

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10160