[Bug c/37757] New: When -Os is enabled, gcc generates a loop where there is none

[Bug c/37757] New: When -Os is enabled, gcc generates a loop where there is none

[rick at efn dot org]

When -Os is enabled, gcc generates a loop where there is none.

gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.3.2-1'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-targets=all --enable-cld
--enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu
--target=i486-linux-gnu
Thread model: posix
gcc version 4.3.2 (Debian 4.3.2-1) 

Command line:
gcc -Os -c -Wa,-alh,-L test.c > /tmp/test.opt.lis
# Removing "-Os" removes bug

No warnings, errors or output

files:
http://www.efn.org/~rick/pub/test.i
http://www.efn.org/~rick/pub/test.c


-- 
           Summary: When -Os is enabled, gcc generates a loop where there is
                    none
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: rick at efn dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37757

[Bug c/37757] When -Os is enabled, gcc generates a loop where there is none

[rick at efn dot org]

------- Comment #1 from rick at efn dot org  2008-10-06 22:36 -------
Created an attachment (id=16466)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16466&action=view)
Source file


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37757

[Bug c/37757] When -Os is enabled, gcc generates a loop where there is none

[rick at efn dot org]

------- Comment #2 from rick at efn dot org  2008-10-06 22:37 -------
Created an attachment (id=16467)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16467&action=view)
i file


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37757

[Bug target/37757] When -Os is enabled, gcc generates a loop where there is none

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2008-10-06 23:37 -------
Hmm, works with -march=i668 as that enables ifcvt.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |target
           Keywords|                            |wrong-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37757

[Bug target/37757] When -Os is enabled, gcc generates a loop where there is none

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2008-10-07 07:42 -------
I don't see a loop.  Also the testcase doesn't link.  Can you clarify what you
think is the bug?


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37757

[Bug target/37757] When -Os is enabled, gcc generates a loop where there is none

[rick at efn dot org]

------- Comment #5 from rick at efn dot org  2008-10-07 13:55 -------
(In reply to comment #4)
> I don't see a loop.  Also the testcase doesn't link.  Can you clarify what you
> think is the bug?
> 

  You are right, there is no loop.  The optimizer managed to make me think
there was one...  Very sorry about the noise.


-- 

rick at efn dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37757