[Bug fortran/35662] New: [4.3 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[Bug fortran/35662] New: [4.3 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[kmccarty at debian dot org]

Hi,

On Debian's mips and mipsel ports, gfortran 4.3 at -O1 or higher generates
object code that calls the sincosf() function in glibc's libm.  Unfortunately
the function call does not produce the correct result: it returns 0 for the
sine and 1 for the cosine.  Since an equivalent C program that uses sincosf()
does yield the right results, I conclude that it is gfortran and not libm where
the bug occurs -- somehow the call to sincosf() in the generated object code is
wrong.  (Not being too knowledgeable on either MIPS or assembly, I
unfortunately can't tell you why.  An erroneous assumption about the byte size
of the sine and cosine values returned by sincosf(), perhaps?)

This is a regression from gfortran 4.2.3, but the reason is apparently that
previous gfortran versions do not generate calls to sincosf().

Version information:

(sid)kmccarty@larsa:~$ gfortran-4.3 -v
Using built-in specs.
Target: mips-linux-gnu
Configured with: ../src/configure linux gnu
Thread model: posix
gcc version 4.3.1 20080309 (prerelease) (Debian 4.3.0-1)

Test case is at
http://people.debian.org/~kmccarty/gfortran-sincos-err-mips.tar.gz

The FORTRAN code is "sincos.F", and equivalent C code (I translated the FORTRAN
to C by hand) that explicitly uses sincosf() is "sincos.c".

The bad object code is located in subdirectories obj-fail/-O1 and obj-fail/-O2
of the tarball.  Correct object code generated at -O0 is in obj-success/-O0,
but may not be that useful for comparison, as the generated assembly with no
optimization calls the sinf() and cosf() functions individually.  Output of the
FORTRAN and C programs are in "output.txt" and "coutput.txt", respectively, in
each subdirectory.

You can quickly regenerate these files with "make output".

best regards,
Kevin McCarty


-- 
           Summary: [4.3 regression] gfortran interfaces badly with glibc
                    sincosf() causing breakage
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kmccarty at debian dot org
 GCC build triplet: mips-linux-gnu
  GCC host triplet: mips-linux-gnu
GCC target triplet: mips-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662

[Bug target/35662] [4.3/4.4 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|fortran                     |target
           Keywords|                            |wrong-code
            Summary|[4.3 regression] gfortran   |[4.3/4.4 regression]
                   |interfaces badly with glibc |gfortran interfaces badly
                   |sincosf() causing breakage  |with glibc sincosf() causing
                   |                            |breakage
   Target Milestone|---                         |4.3.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662

[Bug target/35662] [4.3/4.4 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[jakub at gcc dot gnu dot org]

------- Comment #1 from jakub at gcc dot gnu dot org  2008-04-15 11:20 -------
This is a fortran FE bug.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |jakub at gcc dot gnu dot org
                   |dot org                     |
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
           Priority|P3                          |P2
   Last reconfirmed|0000-00-00 00:00:00         |2008-04-15 11:20:07
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662

[Bug target/35662] [4.3/4.4 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[jakub at gcc dot gnu dot org]

-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P4


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662

[Bug target/35662] [4.3/4.4 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[jakub at gcc dot gnu dot org]

------- Comment #2 from jakub at gcc dot gnu dot org  2008-04-16 15:57 -------
Subject: Bug 35662

Author: jakub
Date: Wed Apr 16 15:56:58 2008
New Revision: 134349

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=134349
Log:
        PR target/35662
        * f95-lang.c (gfc_init_builtin_functions): Make sure
        BUILT_IN_SINCOS{,F,L} types aren't varargs.

        * gfortran.dg/pr35662.f90: New test.

Added:
    trunk/gcc/testsuite/gfortran.dg/pr35662.f90
Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/f95-lang.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662

[Bug target/35662] [4.3/4.4 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2008-04-16 16:06 -------
Subject: Bug 35662

Author: jakub
Date: Wed Apr 16 16:05:51 2008
New Revision: 134352

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=134352
Log:
        PR target/35662
        * f95-lang.c (gfc_init_builtin_functions): Make sure
        BUILT_IN_SINCOS{,F,L} types aren't varargs.

        * gfortran.dg/pr35662.f90: New test.

Added:
    branches/gcc-4_3-branch/gcc/testsuite/gfortran.dg/pr35662.f90
Modified:
    branches/gcc-4_3-branch/gcc/fortran/ChangeLog
    branches/gcc-4_3-branch/gcc/fortran/f95-lang.c
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662

[Bug target/35662] [4.3/4.4 regression] gfortran interfaces badly with glibc sincosf() causing breakage

[jakub at gcc dot gnu dot org]

------- Comment #4 from jakub at gcc dot gnu dot org  2008-04-16 16:11 -------
Fixed.


-- 

jakub at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35662