[Bug libfortran/26712] New: gfortran on mac intel runtime floating point exception when printing

[Bug libfortran/26712] New: gfortran on mac intel runtime floating point exception when printing

[ccb at dl dot ac dot uk]

All attempts to run code compiled with gfortran fail if there is a floating
point print.  This seems to be 
due to a floating point underflow exception being invoked.

cat test.f
      program test
      real a
      a = 10.0
      print *,a
      stop
      end

gdb stack trace follows:

(gdb) run
Starting program: /Users/charlesb/a.out 
Reading symbols for shared libraries .++ done

Program received signal EXC_ARITHMETIC, Arithmetic exception.
0x900e5158 in __gdtoa ()
(gdb) where
#0  0x900e5158 in __gdtoa ()
#1  0x900e47f8 in __ldtoa ()
#2  0x9000c947 in __vfprintf ()
#3  0x9000baf0 in sprintf ()
#4  0x0024d968 in output_float (dtp=0xbfffefb0, f=0x400390, value=10) at
../../../gcc-4.1.0/
libgfortran/io/write.c:472
#5  0x0024e597 in write_float (dtp=0xbfffefb0, f=0xbfffef08, source=0x3ff40000
<Address 
0x3ff40000 out of bounds>, len=4) at
../../../gcc-4.1.0/libgfortran/io/write.c:898
#6  0x0024e6a9 in write_real (dtp=0xbfffefb0, source=0xbfffe368 "",
length=1072955392) at ../../../
gcc-4.1.0/libgfortran/io/write.c:1390
#7  0x0024f06d in *__gfortrani_list_formatted_write (dtp=0xbfffefb0,
type=BT_REAL, p=0xbffff0c0, 
kind=4, size=4, nelems=1) at ../../../gcc-4.1.0/libgfortran/io/write.c:1460
#8  0x002486f0 in *__gfortran_transfer_real (dtp=0xbfffefb0, p=0xbffff0c0,
kind=4) at ../../../
gcc-4.1.0/libgfortran/io/transfer.c:1079
#9  0x00001ebb in MAIN__ () at test.f:4
#10 0x00001efc in main (argc=-1073745608, argv=0x1de6) at
../../../gcc-4.1.0/libgfortran/fmain.c:
18

Specs of compiler version:
Using built-in specs.
Target: i386-apple-darwin8.5.1
Configured with: ../gcc-4.1.0/configure --enable-languages=c,c++,fortran,java
Thread model: posix
gcc version 4.1.0


-- 
           Summary: gfortran on mac intel runtime floating point exception
                    when  printing
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libfortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ccb at dl dot ac dot uk
 GCC build triplet: i386-apple-darwin8.5.1
  GCC host triplet: i386-apple-darwin8.5.1
GCC target triplet: i386-apple-darwin8.5.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[ccb at dl dot ac dot uk]

------- Comment #1 from ccb at dl dot ac dot uk  2006-03-16 12:35 -------
I have played with this some more, and it seems to be an floating point
underflow.  Default configure results in FPU_HOST_HEADER=config/fpu-387.h,
however, Darwin on i386 uses a fenv.h that is similar to that in
config/fpu-glibc.h. 

By editing fpu-glibc.h I can run test.f successfully.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-03-16 13:17 -------
Hmm, I wonder if this is related to:
http://lists.apple.com/archives/Darwin-dev/2006/Mar/msg00102.html


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[pinskia at gcc dot gnu dot org]

------- Comment #3 from pinskia at gcc dot gnu dot org  2006-03-16 13:32 -------
(In reply to comment #1)
> I have played with this some more, and it seems to be an floating point
> underflow.  Default configure results in FPU_HOST_HEADER=config/fpu-387.h,
> however, Darwin on i386 uses a fenv.h that is similar to that in
> config/fpu-glibc.h. 

Are you saying that fpu-387.h is not working correctly so you used fpu-glibc.h
but modified it for darwin's fenv.h?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[ccb at dl dot ac dot uk]

------- Comment #4 from ccb at dl dot ac dot uk  2006-03-16 14:30 -------
Created an attachment (id=11058)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11058&action=view)
fpu configuration file for mactel, uses apple supplied fenv.h

For clearing this uses feclearexcept (FE_ALL_EXCEPT)
For getting a pointer to the exception control fegetexceptflag(&mode,
FE_ALL_EXCEPT) is used.
For setting individual flags fesetexceptflag (&mode, FE_DENORMAL) is used.

To use this file, some changes are required to configure.host, inparticular,
host_cpu='i386'
host_os='darwin8.5.1'


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[ccb at dl dot ac dot uk]

------- Comment #5 from ccb at dl dot ac dot uk  2006-03-17 10:13 -------
How do I put this.  The apple fenv.h supplied functions "work" by only setting
bits in mxcsr (not cw), and then only setting bits 1-6.  Problem is that the
actual working bits are in 7-12 (as in fpu-387.h).  So my little test.f runs
with the default mask (all bits on).  I get the failure when using gfortran as
the mxcsr bits
are all set off (same test.f as above, default compilation)

0x37f is cw
0 is cw_sse
Floating point exception

defalt cw_sse is 0x1f80 .


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[ccb at dl dot ac dot uk]

------- Comment #6 from ccb at dl dot ac dot uk  2006-03-17 11:30 -------
Created an attachment (id=11062)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11062&action=view)
fpu-387.h based fpe control for mactel

The changes are to the SSE elements.  It sets a mask as for the local floating
point registers.  This seems to work for the fortran code I deal with.


-- 

ccb at dl dot ac dot uk changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #11058|0                           |1
        is obsolete|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[fxcoudert at gcc dot gnu dot org]

------- Comment #7 from fxcoudert at gcc dot gnu dot org  2006-03-25 09:27 -------
Could you run the testsuite with this change and report it (to gcc-testresults
and fortran mailing lists)?


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |fxcoudert at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[schnetter at aei dot mpg dot de]

------- Comment #8 from schnetter at aei dot mpg dot de  2006-03-30 16:18 -------
I had the same problem.  I replaced this file, ran the test cases, and sent the
results.  The summary is

                === gfortran Summary ===

# of expected passes            12636
# of unexpected failures        1
# of expected failures          7
# of unsupported tests          46
/Users/eschnett/src/gcc-build/gcc/testsuite/gfortran/../../gfortran  version
4.2
.0 20060329 (experimental)

with the unexpected failure

FAIL: gfortran.dg/assign_2.f90  -O0  (test for excess errors)
WARNING: gfortran.dg/assign_2.f90  -O0  compilation failed to produce
executable

which seems unrelated to me after looking at the source code and error message
of that file.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[fxcoudert at gcc dot gnu dot org]

------- Comment #9 from fxcoudert at gcc dot gnu dot org  2006-03-30 22:00 -------
Subject: Bug 26712

Author: fxcoudert
Date: Thu Mar 30 22:00:21 2006
New Revision: 112546

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=112546
Log:
        PR libfortran/26712
        * config/fpu-387.h: Add special case for handling of SSE
        control bit on i386-darwin.

Modified:
    trunk/libgfortran/ChangeLog
    trunk/libgfortran/config/fpu-387.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[fxcoudert at gcc dot gnu dot org]

------- Comment #10 from fxcoudert at gcc dot gnu dot org  2006-03-30 22:04 -------
Can someone confirm this issue is now fixed on trunk? I'd then apply the patch
to 4.1 as well.

And Erik, btw, the assign_2.f90 failure is PR25765.


-- 

fxcoudert at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |fxcoudert at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-03-30 22:04:44
               date|                            |
   Target Milestone|---                         |4.1.1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[pinskia at gcc dot gnu dot org]

------- Comment #11 from pinskia at gcc dot gnu dot org  2006-03-30 22:08 -------
4.1.x is broken for i686-darwin other ways so this is not to be fixed for
there.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.1.1                       |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[fxcoudert at gcc dot gnu dot org]

------- Comment #12 from fxcoudert at gcc dot gnu dot org  2006-04-01 10:07 -------
(In reply to comment #11)
> 4.1.x is broken for i686-darwin other ways so this is not to be fixed for
> there.

If 4.1.x is broken, how do you explain that g95 (based on 4.0.3 or 4.1.0) is
working on i686-darwin?

Anyway, reopening this PR for a nicer solution, maybe one that involves a
generic darwin way to do this (generic for both ppc and i686)?


-- 

fxcoudert at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[schnetter at aei dot mpg dot de]

------- Comment #13 from schnetter at aei dot mpg dot de  2006-04-01 17:21 -------
Regarding a generic mechanism for both ppc and i386 on Darwin:

I looked at the header files in /usr/include on my Darwin 8.5.2 system, which
contain the architecture specific files for both ppc and i386.  While the ppc
headers have a file fp_regs.h, there is no such file for i386.  I don't think
that Darwin supports a generic architecture-independent mechanism for FPU
control.

The gfortran library contains explicit machine instructions in its file
fpu-387.h, which seem to be used on all i386 architectures that don't have a
glibc.  How many architectures are that?  It seems to me as if this file is
broken for SSE (after this patch, it remains broken on non-Darwin
architectures):

The variable cw_sse has first its low 16 bits set to zero.  Then some bits are
set to one.  Then the same bits are set to one depending on front-end flags. 
This is pointless.  The code also uses explicit numbers to indicate the bits
although perfectly nice named constants exist.

It seems to me that the whole #else branch of the #if __APPLE__ statement
should be removed, together with the #if statement itself.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712

[Bug libfortran/26712] gfortran on mac intel runtime floating point exception when printing

[fxcoudert at gcc dot gnu dot org]

------- Comment #14 from fxcoudert at gcc dot gnu dot org  2006-04-01 21:26 -------
(In reply to comment #13)
> It seems to me that the whole #else branch of the #if __APPLE__ statement
> should be removed, together with the #if statement itself.

Right. I tested a bit with sqrt() SSE2 instructions, and it seems that the code
enclosed in the __APPLE__ case does what is needed. I just commited this.
Closing.


-- 

fxcoudert at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26712