[Bug c++/12092] New: ICE: Floating point exception

[Bug c++/12092] New: ICE: Floating point exception

[wmertens at gentoo dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

           Summary: ICE: Floating point exception
           Product: gcc
           Version: 3.3.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: wmertens at gentoo dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu

configured with: /var/tmp/portage/gcc-3.3.1/work/gcc-3.3.1/configure
--prefix=/usr --bindir=/usr/i686-pc-linux-gnu/gcc-bin/3.3
--includedir=/usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.1/include
--datadir=/usr/share/gcc-data/i686-pc-linux-gnu/3.3
--mandir=/usr/share/gcc-data/i686-pc-linux-gnu/3.3/man
--infodir=/usr/share/gcc-data/i686-pc-linux-gnu/3.3/info --enable-shared
--host=i686-pc-linux-gnu --target=i686-pc-linux-gnu --with-system-zlib
--enable-languages=c,c++,ada,f77,objc --enable-threads=posix --enable-long-long
--disable-checking --enable-cstdio=stdio --enable-clocale=generic
--enable-__cxa_atexit --enable-version-specific-runtime-libs
--with-gxx-include-dir=/usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.1/include/g++-v3
--with-local-prefix=/usr/local --enable-shared --enable-nls
--without-included-gettext --disable-multilib

System is a Pentium 4.

When compiling gst-plugins, I get a floating point exception. I'll attach the
preprocessed source.

gcc -DHAVE_CONFIG_H -I. -I. -I../.. -O3 -mcpu=i486 -fschedule-insns2
-funroll-all-loops -finline-functions -ffast-math -DNDEBUG -I../../gst-libs
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pthread -I/usr/include/gstreamer-0.6
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/libxml2
-DGST_DISABLE_DEPRECATED -g -O2 -march=pentium4 -fprefetch-loop-arrays -pipe -c
codec.c -MT libgstmpeg1encoder_la-codec.lo -MD -MP -MF
.deps/libgstmpeg1encoder_la-codec.TPlo  -fPIC -DPIC -o
libgstmpeg1encoder_la-codec.lo
codec.c: In function `DecodeAC':
codec.c:286: internal compiler error: Floating point exception

[Bug c++/12092] ICE: Floating point exception

[wmertens at gentoo dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092



------- Additional Comments From wmertens at gentoo dot org  2003-08-28 09:48 -------
Created an attachment (id=4669)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=4669&action=view)
Preprocessed source

[Bug c++/12092] ICE: Floating point exception

[wmertens at gentoo dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092



------- Additional Comments From wmertens at gentoo dot org  2003-08-28 10:24 -------
When I compile with 
CFLAGS="-O2 -march=pentium4 -pipe"

it doesn't ICE.

[Bug c++/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092



------- Additional Comments From pinskia at gcc dot gnu dot org  2003-08-28 12:51 -------
Most likely the same bug as PR 9971 but with a different code.

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|c++                         |optimization
     Ever Confirmed|                            |1
           Keywords|                            |ice-on-valid-code
   Last reconfirmed|0000-00-00 00:00:00         |2003-08-28 13:00:55
               date|                            |


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-08-28 13:00 -------
I can confirm this on the mainline (20030827).
Reduced source:
void DecodeAC(int index,int *matrix)
{
  int *mptr;

  for(mptr=matrix+index;mptr<matrix+64;mptr++) {*mptr = 0;}
}
Comand line: gcc  -funroll-all-loops -ffast-math -O2 -mtune=i486 -march=pentium4 -
fprefetch-loop-arrays pr12092.c.

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |danwmathews at yahoo dot com


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-08-28 13:02 -------
*** Bug 9971 has been marked as a duplicate of this bug. ***

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2003-08-28 13:00:55         |2003-08-29 16:30:24
               date|                            |


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-08-29 16:30 -------
Something here is causing it:
>From loop.c:
4030          /* Prefetch might be worthwhile only when the loads/stores are dense.  */
4031          if (PREFETCH_ONLY_DENSE_MEM)
4032            if (density * 256 > PREFETCH_DENSE_MEM * 100
4033                && (info[i].total_bytes / PREFETCH_BLOCK                        <--- I want to say 
this guy is causing it
4034                    >= PREFETCH_BLOCKS_BEFORE_LOOP_MIN))

And it is PREFETCH_BLOCK is defined as ix86_cost->prefetch_block which is zero at 
this point because we are tuning for i486 (which does not have prefetch at all) but our 
arch is pentium4 which does have prefetch so we try to use prefetch but we need to 
figure out if it is good to prefetch so we do a divide on PREFETCH_BLOCK but since 
PREFETCH_BLOCK is zero here, we get an floating exception.

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092


pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |pinskia at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Target Milestone|---                         |3.4


------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-01 04:34 -------
I think this patch will fix it but I have no way to test it as bootstrap fails for me before 
applying the patch (once GCC gets back bootstrapping, I will submit this):
Index: loop.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/loop.c,v
retrieving revision 1.469
diff -u -d -b -w -u -p -r1.469 loop.c
--- loop.c      30 Jul 2003 20:28:45 -0000      1.469
+++ loop.c      1 Sep 2003 04:32:20 -0000
@@ -4029,7 +4029,7 @@ emit_prefetch_instructions (struct loop 
 
       /* Prefetch might be worthwhile only when the loads/stores are dense.  */
       if (PREFETCH_ONLY_DENSE_MEM)
-       if (density * 256 > PREFETCH_DENSE_MEM * 100
+       if (PREFETCH_BLOCK != 0 && density * 256 > PREFETCH_DENSE_MEM * 100
            && (info[i].total_bytes / PREFETCH_BLOCK
                >= PREFETCH_BLOCKS_BEFORE_LOOP_MIN))
          {
@@ -4050,7 +4050,7 @@ emit_prefetch_instructions (struct loop 
        info[i].prefetch_in_loop = 1, info[i].prefetch_before_loop = 1;
 
       /* Find how many prefetch instructions we'll use within the loop.  */
-      if (info[i].prefetch_in_loop != 0)
+      if (info[i].prefetch_in_loop != 0 && PREFETCH_BLOCK != 0)
        {
          info[i].prefetch_in_loop = ((info[i].stride + PREFETCH_BLOCK - 1)
                                  / PREFETCH_BLOCK);
@@ -4085,7 +4085,7 @@ emit_prefetch_instructions (struct loop 
        info[i].prefetch_in_loop = 0;
 
       /* Find how many prefetch instructions we'll use before the loop.  */
-      if (info[i].prefetch_before_loop != 0)
+      if (info[i].prefetch_before_loop != 0) && PREFETCH_BLOCK != 0
        {
          int n = info[i].total_bytes / PREFETCH_BLOCK;
          if (n > ahead)

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092



------- Additional Comments From pinskia at gcc dot gnu dot org  2003-09-08 06:06 -------
A new version of the patch which works and submitted: <http://gcc.gnu.org/ml/gcc-
patches/2003-09/msg00449.html>

[Bug optimization/12092] ICE: Floating point exception

[kcook at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092



------- Additional Comments From kcook at gcc dot gnu dot org  2003-09-09 20:18 -------
A different question is shouldn't -march=pentium4 -mtune=i486 be declared invalid?

To me, tuning (ie scheduling) for a processor that is less than the baseline
architecture (which -march specifies) just seems wrong.

The 486 didn't know about SSE2, it didn't know about SSE, it didn't know about
MMX, it didn't even know about CMOV, but by specifying -march=pentium4 all of
those features are enabled.  So, there is no way for the scheduler to come up
with a correct schedule.

[Bug optimization/12092] ICE: Floating point exception

[zack at gcc dot gnu dot org]

------- Additional Comments From zack at gcc dot gnu dot org  2003-12-02 00:47 -------
Please revise your patch according to Jim's suggestions and resubmit.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|3.4                         |3.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-02-08 06:35 -------
Not working on updating the patch (too much others things to do).

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|pinskia at gcc dot gnu dot  |unassigned at gcc dot gnu
                   |org                         |dot org
             Status|ASSIGNED                    |NEW
   Target Milestone|3.5.0                       |---


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug rtl-optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-28 13:00 -------
*** Bug 17710 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bangerth at dealii dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug rtl-optimization/12092] ICE: Floating point exception

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-02 00:15 -------
Subject: Bug 12092

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	sayle@gcc.gnu.org	2005-01-02 00:15:01

Modified files:
	gcc            : ChangeLog loop.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: pr12092-1.c 

Log message:
	PR rtl-optimization/12092
	* loop.c (emit_prefetch_instructions): Do nothing if PREFETCH_BLOCK
	is zero.
	
	* gcc.dg/pr12092-1.c: New test case.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6998&r2=2.6999
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&r1=1.518&r2=1.519
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4832&r2=1.4833
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/pr12092-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug rtl-optimization/12092] ICE: Floating point exception

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-02 00:19 -------
Fixed in 4.0.0.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug rtl-optimization/12092] ICE: Floating point exception

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-02 16:46 -------
Subject: Bug 12092

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-3_4-branch
Changes by:	sayle@gcc.gnu.org	2005-01-02 16:46:46

Modified files:
	gcc            : ChangeLog loop.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.dg: pr12092-1.c 

Log message:
	PR rtl-optimization/12092
	* loop.c (emit_prefetch_instructions): Do nothing if PREFETCH_BLOCK
	is zero.
	
	* gcc.dg/pr12092-1.c: New test case.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=2.2326.2.759&r2=2.2326.2.760
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/loop.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.488.2.6&r2=1.488.2.7
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3389.2.338&r2=1.3389.2.339
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/pr12092-1.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092

[Bug rtl-optimization/12092] ICE: Floating point exception

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-01-03 03:34 -------
Subject: Bug 12092

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	hp@gcc.gnu.org	2005-01-03 03:33:58

Modified files:
	gcc/testsuite  : ChangeLog 
	gcc/testsuite/gcc.dg: pr12092-1.c 

Log message:
	PR rtl-optimization/12092
	* gcc.dg/pr12092-1.c: Fix typo in dg directive.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4836&r2=1.4837
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.dg/pr12092-1.c.diff?cvsroot=gcc&r1=1.2&r2=1.3



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12092