Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[Steven Bosscher]

The following reply was made to PR optimization/10171; it has been noted by GNATS.

From: Steven Bosscher <s.bosscher@student.tudelft.nl>
To: gcc-gnats@gcc.gnu.org, mchen@vmware.com, gcc-bugs@gcc.gnu.org,
	nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org, agesen@vmware.com,
	mendel@vmware.com, janis187@us.ibm.com
Cc:  
Subject: Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined
 function
Date: Sat, 22 Mar 2003 23:22:32 +0100

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171
 
 Janis,
 
 If the patch you identified really breaks stuff, then this PR should be 
 in the
 category "target", agree?
 
 Greetz
 Steven
 
 

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[jason]

Synopsis: [3.2/3.3/3.4 regression] wrong code for inlined function

Responsible-Changed-From-To: unassigned->jason
Responsible-Changed-By: jason
Responsible-Changed-When: Tue Mar 25 20:36:55 2003
Responsible-Changed-Why:
    x
State-Changed-From-To: analyzed->closed
State-Changed-By: jason
State-Changed-When: Tue Mar 25 20:36:55 2003
State-Changed-Why:
    fixed

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[Janis Johnson]

The following reply was made to PR optimization/10171; it has been noted by GNATS.

From: Janis Johnson <janis187@us.ibm.com>
To: Steven Bosscher <s.bosscher@student.tudelft.nl>
Cc: gcc-gnats@gcc.gnu.org, mchen@vmware.com, gcc-bugs@gcc.gnu.org,
   nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org, agesen@vmware.com,
   mendel@vmware.com, janis187@us.ibm.com
Subject: Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function
Date: Sat, 22 Mar 2003 15:01:50 -0800

 On Sat, Mar 22, 2003 at 11:22:32PM +0100, Steven Bosscher wrote:
 > http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171
 > 
 > Janis,
 > 
 > If the patch you identified really breaks stuff, then this PR should be 
 > in the
 > category "target", agree?
 
 Not necessarily; see Jason's comment about how -O2 does some unrolling.
 The identified patch might have merely made that change (as far as this
 problem is concerned).

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[Janis Johnson]

The following reply was made to PR optimization/10171; it has been noted by GNATS.

From: Janis Johnson <janis187@us.ibm.com>
To: gcc-gnats@gcc.gnu.org, mchen@vmware.com, gcc-bugs@gcc.gnu.org,
   nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org, agesen@vmware.com,
   mendel@vmware.com
Cc:  
Subject: Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined 
 function
Date: Sat, 22 Mar 2003 13:40:07 -0800

 Not that it's useful, but for i686-linux the regression
 appears with this patch:
 
 Wed Sep  1 21:13:48 1999  Richard Henderson  <rth@cygnus.com>
 
         Merge new ia32 backend from the branch!
 
         * i386.h, i386.c, i386.md, reg-stack.c, i386/unix.h: Many
 changes.
         See ChangeLog.P2 on new_ia32_branch for details.
 
         * rtl.h (stack_regs_mentioned_p): Delete prototype.
         * i386/cygwin.h (SUBTARGET_PROLOGUE): No more do_rtl.
         * i386/win32.h (SUBTARGET_PROLOGUE): Likewise.
         * i386/gas.h (ASM_FILE_START): Define.
         * i386/winnt.c (i386_pe_valid_decl_attribute_p): Update
         for name change of ix86_valid_decl_attribute_p.
         (i386_pe_valid_type_attribute_p): Similarly.
 
 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171
 
 
 

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[Jason Merrill]

The following reply was made to PR optimization/10171; it has been noted by GNATS.

From: Jason Merrill <jason@redhat.com>
To: Steven Bosscher <s.bosscher@student.tudelft.nl>
Cc: gcc-gnats@gcc.gnu.org, mchen@vmware.com, gcc-bugs@gcc.gnu.org,
   nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org, agesen@vmware.com,
   mendel@vmware.com
Subject: Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for
 inlined function
Date: Fri, 21 Mar 2003 18:45:52 -0500

 On Sat, 22 Mar 2003 00:33:02 +0100, Steven Bosscher <s.bosscher@student.tudelft.nl> wrote:
 
 >  From your analysis, I would suspect that this PR is a duplicate
 > of high-priority PR opt/8414. Is there any way to verify this?
 
 I don't think so; it doesn't look like the loop in 8414 only has a single
 iteration.
 
 Jason

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[Steven Bosscher]

The following reply was made to PR optimization/10171; it has been noted by GNATS.

From: Steven Bosscher <s.bosscher@student.tudelft.nl>
To: gcc-gnats@gcc.gnu.org, mchen@vmware.com, gcc-bugs@gcc.gnu.org,
	nobody@gcc.gnu.org, gcc-prs@gcc.gnu.org, agesen@vmware.com,
	mendel@vmware.com, jason@gcc.gnu.org
Cc:  
Subject: Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined
 function
Date: Sat, 22 Mar 2003 00:33:02 +0100

 http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171
 
 Jason,
 
  From your analysis, I would suspect that this PR is a duplicate
 of high-priority PR opt/8414. Is there any way to verify this?
 
 (Hoping you *do* have access to IA64 hardware ;-)
 
 Greetz
 Steven
 
 

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[jason]

Synopsis: [3.2/3.3/3.4 regression] wrong code for inlined function

State-Changed-From-To: open->analyzed
State-Changed-By: jason
State-Changed-When: Fri Mar 21 06:17:28 2003
State-Changed-Why:
    This is a bug in loop unrolling; 2.95 shows the bug with
    -funroll-loops.  The only difference is that now we do some
    unrolling at -O2.
    
    The loop optimizer properly calculates that there will
    always be a single pass through the loop.  The unroller
    has a special case for this.  It looks for and deletes an
    unconditional jump to the continue point, then deletes a
    conditional jump from the end of the loop.  Unfortunately,
    this code fails to handle nontrivial for loops, as the
    unconditional jump at the beginning of the loop (created
    previously by loop inversion) is to the test, not to the
    continue point.  So that jump is not deleted, but the
    conditional jump at the end is, and so we just skip over
    the loop.  Oops.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[jason]

Synopsis: [3.2/3.3/3.4 regression] wrong code for inlined function

State-Changed-From-To: analyzed->open
State-Changed-By: jason
State-Changed-When: Fri Mar 21 06:10:14 2003
State-Changed-Why:
    x

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171

Re: optimization/10171: [3.2/3.3/3.4 regression] wrong code for inlined function

[bangerth]

Old Synopsis: contant inline function result evaluated wrong
New Synopsis: [3.2/3.3/3.4 regression] wrong code for inlined function

State-Changed-From-To: open->analyzed
State-Changed-By: bangerth
State-Changed-When: Thu Mar 20 19:09:33 2003
State-Changed-Why:
    Confirmed. Here's the same program, slightly modified:
    ------------------------
    inline int tag() { return 0; }
    
    int main() {
       int i;
       for (i = 0; i < (tag() ? 2 : 1); i++)
         printf("Hello1\n");
    }
    --------------------------
    The loop should be executed at least once, but isn't when
    compiled with -O2 on 3.2, 3.3 and mainline. It worked with
    2.95, though, so this is a regression. A serious one, I'd
    say.
    
    W.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=10171