PowerPC64 + Ada + RTEMS: Infinite loop in process_bb_lives()

PowerPC64 + Ada + RTEMS: Infinite loop in process_bb_lives()

[Sebastian Huber]

Hello,

I added support for the 64-bit PowerPC some months ago using a variant 
of the ELFv2 ABI. I don't know which kind of long double support I use 
on this target. This is difficult for me to understand how this works on 
64-bit PowerPC. This was no problem up to now since nobody used long 
double with RTEMS on this target. I tried to build a GCC with Ada 
support today for the powerpc-rtems5 target. It ends up in infinite 
loops while building the Ada run-time multilib for a 64-bit PowerPC 
variant (similar a-coteio.ads):

gdb --args /build/git-build/b-gcc-git-powerpc-rtems5/./gcc/gnat1 -gnatwa 
-quiet -nostdinc -nostdinc -dumpbase a-scteio.ads -auxbase-strip 
a-scteio.o -O2 -Wextra -Wall -g -mcpu=e6500 -msoft-float -gnatpg 
-mcpu=e6500 -m64 -msoft-float -mno-altivec -gnatO a-scteio.o a-scteio.ads
...
(gdb) bt
#0  process_bb_lives (bb=0x7ffff700a680, curr_point=@0x7fffffffd38c: 
387, dead_insn_p=dead_insn_p@entry=false) at 
/scratch/svn-gcc/gcc/lra-lives.c:838
#1  0x0000000000b32b3a in lra_create_live_ranges_1 
(all_p=all_p@entry=true, dead_insn_p=dead_insn_p@entry=false) at 
/scratch/svn-gcc/gcc/lra-lives.c:1305
#2  0x0000000000b33620 in lra_create_live_ranges 
(all_p=all_p@entry=true, dead_insn_p=dead_insn_p@entry=false) at 
/scratch/svn-gcc/gcc/lra-lives.c:1369
#3  0x0000000000b159c2 in lra (f=<optimized out>) at 
/scratch/svn-gcc/gcc/lra.c:2438
#4  0x0000000000ac95d2 in do_reload () at /scratch/svn-gcc/gcc/ira.c:5443
#5  (anonymous namespace)::pass_reload::execute (this=<optimized out>) 
at /scratch/svn-gcc/gcc/ira.c:5627
#6  0x0000000000bc1d49 in execute_one_pass (pass=pass@entry=0x24cc430) 
at /scratch/svn-gcc/gcc/passes.c:2497
#7  0x0000000000bc25f1 in execute_pass_list_1 (pass=0x24cc430) at 
/scratch/svn-gcc/gcc/passes.c:2586
#8  0x0000000000bc2603 in execute_pass_list_1 (pass=0x24cb350) at 
/scratch/svn-gcc/gcc/passes.c:2587
#9  0x0000000000bc2645 in execute_pass_list (fn=<optimized out>, 
pass=<optimized out>) at /scratch/svn-gcc/gcc/passes.c:2597
#10 0x0000000000883683 in cgraph_node::expand (this=0x7ffff6fd6000) at 
/scratch/svn-gcc/gcc/cgraphunit.c:2139
#11 0x0000000000884bd1 in expand_all_functions () at 
/scratch/svn-gcc/gcc/cgraphunit.c:2275
#12 symbol_table::compile (this=this@entry=0x7ffff6e48000) at 
/scratch/svn-gcc/gcc/cgraphunit.c:2623
#13 0x0000000000887477 in symbol_table::compile (this=0x7ffff6e48000) at 
/scratch/svn-gcc/gcc/cgraphunit.c:2719
#14 symbol_table::finalize_compilation_unit (this=0x7ffff6e48000) at 
/scratch/svn-gcc/gcc/cgraphunit.c:2716
#15 0x0000000000c938dd in compile_file () at 
/scratch/svn-gcc/gcc/toplev.c:480
#16 0x000000000044485d in do_compile () at 
/scratch/svn-gcc/gcc/toplev.c:2059
#17 toplev::main (this=this@entry=0x7fffffffd72e, argc=<optimized out>, 
argc@entry=23, argv=<optimized out>, argv@entry=0x7fffffffd828) at 
/scratch/svn-gcc/gcc/toplev.c:2194
#18 0x0000000000446bdb in main (argc=23, argv=0x7fffffffd828) at 
/scratch/svn-gcc/gcc/main.c:39
(gdb)

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber@embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.

Re: PowerPC64 + Ada + RTEMS: Infinite loop in process_bb_lives()

[Segher Boessenkool]

Hi!

On Mon, Dec 04, 2017 at 03:34:09PM +0100, Sebastian Huber wrote:
> I added support for the 64-bit PowerPC some months ago using a variant 
> of the ELFv2 ABI. I don't know which kind of long double support I use 
> on this target. This is difficult for me to understand how this works on 
> 64-bit PowerPC. This was no problem up to now since nobody used long 
> double with RTEMS on this target. I tried to build a GCC with Ada 
> support today for the powerpc-rtems5 target. It ends up in infinite 
> loops while building the Ada run-time multilib for a 64-bit PowerPC 
> variant (similar a-coteio.ads):

Is this against trunk?  Please open a bug, with enough info so we can
reproduce the problem.  Ideally a simple reduced testcase, but we'll
take whatever you have, as long as it allows to reproduce the problem ;-)

From the dump files it should be obvious what kind of long double you
are using, fwiw.


Segher

Re: PowerPC64 + Ada + RTEMS: Infinite loop in process_bb_lives()

[Sebastian Huber]

On 05/12/17 15:17, Segher Boessenkool wrote:
> Hi!
>
> On Mon, Dec 04, 2017 at 03:34:09PM +0100, Sebastian Huber wrote:
>> I added support for the 64-bit PowerPC some months ago using a variant
>> of the ELFv2 ABI. I don't know which kind of long double support I use
>> on this target. This is difficult for me to understand how this works on
>> 64-bit PowerPC. This was no problem up to now since nobody used long
>> double with RTEMS on this target. I tried to build a GCC with Ada
>> support today for the powerpc-rtems5 target. It ends up in infinite
>> loops while building the Ada run-time multilib for a 64-bit PowerPC
>> variant (similar a-coteio.ads):
> Is this against trunk?  Please open a bug, with enough info so we can
> reproduce the problem.  Ideally a simple reduced testcase, but we'll
> take whatever you have, as long as it allows to reproduce the problem ;-)

Thanks for your offer to look at this problem. I opened a bug:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83387

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber@embedded-brains.de
PGP     : Public key available on request.

Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.