[M3devel] cm3cg failing on linuxlibc6
Peter McKinna
peter.mckinna at gmail.com
Tue May 24 09:24:52 CEST 2016
I may have been a tad hasty in blaming the back end for the crashes, the
front end has some explaining to do as well.
I was getting an infinite loop in a program which I have cut down here to
demonstrate. The original cm3 5.2 I think it
was from elegosoft worked fine. The latest produces different intermediate
code.
First the source, (excuse the size, its extracted from my implementation of
grisu which I was on the point of pushing to github)
MODULE Main;
IMPORT Long,IO,Fmt;
CONST
kUint64MSB = 16_8000000000000000L;
TYPE
Uint64 = Long.T;
PROCEDURE Normalize(sig : Long.T; exp : INTEGER) =
CONST
k10MSBits = 16_FFC0000000000000L;
VAR
significand : Uint64;
exponent : INTEGER;
BEGIN
<*ASSERT sig # 0L *>
significand := sig;
exponent := exp;
(*IO.Put("sig init " & Fmt.LongInt(significand) & "\n");*)
(* This method is mainly called for normalizing boundaries. In general
boundaries need to be shifted by 10 bits. We thus optimize for this
case. *)
WHILE Long.And(significand, k10MSBits) = 0L DO
significand := Long.LeftShift(significand, 10);
(*IO.Put("sig loop 1 " & Fmt.LongInt(significand) & "\n");*)
DEC(exponent, 10);
END;
(*IO.Put("sig after loop 1 " & Fmt.LongInt(significand) & "\n");*)
(*
IO.PutLongInt(Long.And(significand, kUint64MSB));
IO.Put("\n");
*)
WHILE Long.And(significand, kUint64MSB) = 0L DO
(*IO.Put("sig loop2 1 " & Fmt.LongInt(significand) & "\n");*)
significand := Long.LeftShift(significand, 1);
(*IO.Put("sig loop2 2 " & Fmt.LongInt(significand) & "\n");*)
DEC(exponent);
END;
END Normalize;
BEGIN
Normalize(3L,2);
END Main.
Now the correct intermediate from the original cm3
Its a shame we cant embed the cm3 version into the intermediate. But theres
no mention of widechar so you can tell its an old
version.
begin_unit 0
-----FILE ../src/Main.m3 -----
-----LINE 1 -----
# module global constants
declare_segment * -1 T v.1
# module global data
declare_segment M_Main -1 F v.2
-----LINE 45 -----
declare_procedure Main_M3 1 Addr 0 0 T * p.1
declare_param mode 4 4 Int.32 425470580 F F 100 v.3
declare_proctype 1318003907 2 0 0 0
declare_formal sig 89530742
declare_formal exp 425470580
import_procedure Main_I3 0 Addr 0 p.2
export_unit Main
import_procedure Fmt_I3 0 Addr 0 p.3
import_unit Fmt
import_procedure IO_I3 0 Addr 0 p.4
import_unit IO
import_procedure Long_I3 0 Addr 0 p.5
import_unit Long
import_procedure RTHooks_I3 0 Addr 0 p.6
import_unit RTHooks
declare_typename 89530742 Uint64
declare_procedure Main__Normalize 2 Void 0 0 F * p.7
declare_local significand 8 4 Int.64 89530742 F F 50 v.4
declare_local exponent 4 4 Int.32 425470580 F F 50 v.5
declare_param sig 8 4 Int.64 89530742 F F 50 v.6
declare_param exp 4 4 Int.32 425470580 F F 50 v.7
# Normalize
-----LINE 11 -----
begin_procedure p.7
-----LINE 12 -----
-----LINE 19 -----
load v.6 0 Int.64 Int.64
load_integer Int.64 0
if_ne Int.64 L.1 100
import_procedure RTHooks__ReportFault 2 Void 0 p.8
declare_param module 4 4 Addr 138420323 F F 50 v.8
declare_param info 4 4 Int.32 425470580 F F 50 v.9
set_runtime_proc ReportFault p.8
abort 0
. L.1 F
-----LINE 20 -----
load v.6 0 Int.64 Int.64
store v.4 0 Int.64 Int.64
-----LINE 21 -----
load v.7 0 Int.32 Int.32
store v.5 0 Int.32 Int.32
-----LINE 26 -----
jump L.2
. L.3 F
-----LINE 27 -----
load v.4 0 Int.64 Int.64
load_integer Int.32 10
shift_left Int.64
store v.4 0 Int.64 Int.64
-----LINE 29 -----
load v.5 0 Int.32 Int.32
load_integer Int.32 10
subtract Int.32
store v.5 0 Int.32 Int.32
-----LINE 26 -----
. L.2 F
load v.4 0 Int.64 Int.64
load_integer Int.64 -18014398509481984
and Int.64
load_integer Int.64 0
if_eq Int.64 L.3 80
. L.4 F
-----LINE 36 -----
jump L.5
. L.6 F
-----LINE 38 -----
load v.4 0 Int.64 Int.64
load_integer Int.32 1
shift_left Int.64
store v.4 0 Int.64 Int.64
-----LINE 40 -----
load v.5 0 Int.32 Int.32
load_integer Int.32 1
subtract Int.32
store v.5 0 Int.32 Int.32
-----LINE 36 -----
. L.5 F
load v.4 0 Int.64 Int.64
load_integer Int.64 -9223372036854775808
and Int.64
load_integer Int.64 0
if_eq Int.64 L.6 80
. L.7 F
-----LINE 43 -----
exit_proc Void
end_procedure p.7
# Main_M3
# module main body Main_M3
-----LINE 45 -----
begin_procedure p.1
load v.3 0 Int.32 Int.32
if_false Int.32 L.8 0
-----LINE 47 -----
start_call_direct p.7 0 Void
load_integer Int.64 3
pop_param Int.64
load_integer Int.32 2
pop_param Int.32
call_direct p.7 Void
. L.8 F
load_address v.2 0
exit_proc Addr
end_procedure p.1
# global constant type descriptor
declare_record -1 448 0
# global data type descriptor
declare_record -1 896 0
# module global constants
bind_segment v.1 56 4 Struct F T
begin_init v.1
# procedure names
init_chars 0 "Main_M3"
init_chars 8 "Normalize"
# procedure table
init_proc 20 p.1
init_var 24 v.1 0
init_proc 28 p.7
init_var 32 v.1 8
# file name
init_chars 40 "../src/Main.m3"
end_init v.1
# module global data
bind_segment v.2 112 4 Struct F T
begin_init v.2
init_var 0 v.1 40
init_var 20 v.1 20
init_var 36 v.2 52
init_proc 44 p.1
init_int 48 3 Int.32
init_proc 56 p.2
init_var 60 v.2 64
init_proc 68 p.3
init_var 72 v.2 76
init_proc 80 p.4
init_var 84 v.2 88
init_proc 92 p.5
init_var 96 v.2 100
init_proc 104 p.6
end_init v.2
# load map
#
#
# global data allocation for M_Main
# 0 52 4 *module info*
# 52 12 4 import Main
# 64 12 4 import Fmt
# 76 12 4 import IO
# 88 12 4 import Long
# 100 12 4 import RTHooks
# 112 0 4 *TOTAL*
#
#
# global constants for M_Main
# 0 18 4 *proc names*
# 20 20 4 *proc info*
# 40 15 1 *string*
# 56 0 4 *TOTAL*
#
end_unit
Now the intermediate from the latest compiler
begin_unit 0
widechar_size 16
-----FILE ../src/Main.m3 -----
-----LINE 1 -----
# module global constants
declare_segment * -1 T v.1
# module global data
declare_segment M_Main -1 F v.2
-----LINE 45 -----
declare_procedure Main_M3 1 Addr 0 0 T * p.1
declare_param mode 4 4 Int.32 425470580 F F 100 v.3
declare_proctype 1318003907 2 0 0 0
declare_formal sig 89530742
declare_formal exp 425470580
import_procedure Main_I3 0 Addr 0 p.2
export_unit Main
import_procedure Fmt_I3 0 Addr 0 p.3
import_unit Fmt
import_procedure IO_I3 0 Addr 0 p.4
import_unit IO
import_procedure Long_I3 0 Addr 0 p.5
import_unit Long
import_procedure RTHooks_I3 0 Addr 0 p.6
import_unit RTHooks
declare_typename 89530742 Uint64
declare_procedure Main__Normalize 2 Void 0 0 F * p.7
declare_local significand 8 8 Int.64 89530742 F F 50 v.4
declare_local exponent 4 4 Int.32 425470580 F F 50 v.5
declare_param sig 8 8 Int.64 89530742 F F 50 v.6
declare_param exp 4 4 Int.32 425470580 F F 50 v.7
# Normalize
-----LINE 11 -----
begin_procedure p.7
-----LINE 12 -----
-----LINE 19 -----
load_integer Int.64 0
load v.6 0 Int.64 Int.64
if_ne Int.64 L.1 100
declare_proctype -1531209598 2 0 -1 0
declare_formal module 138420323
declare_formal info 425470580
import_procedure RTHooks__ReportFault 2 Void 0 p.8
declare_param module 4 4 Addr 138420323 F F 50 v.8
declare_param info 4 4 Int.32 425470580 F F 50 v.9
set_runtime_proc ReportFault p.8
abort 0
. L.1 F
-----LINE 20 -----
load v.6 0 Int.64 Int.64
store v.4 0 Int.64 Int.64
-----LINE 21 -----
load v.7 0 Int.32 Int.32
store v.5 0 Int.32 Int.32
-----LINE 26 -----
jump L.2
. L.3 F
-----LINE 27 -----
load v.4 0 Int.64 Int.64
load_integer Int.32 10
shift_left Word.64
store v.4 0 Int.64 Int.64
-----LINE 29 -----
load v.5 0 Int.32 Int.32
load_integer Int.32 10
subtract Int.32
store v.5 0 Int.32 Int.32
-----LINE 26 -----
. L.2 F
load_integer Int.64 -18014398509481984
load v.4 0 Int.64 Int.64
and Word.64
load_integer Int.64 0
if_eq Int.64 L.3 80
. L.4 F
-----LINE 36 -----
jump L.5
. L.6 F
-----LINE 38 -----
load v.4 0 Int.64 Int.64
load_integer Int.32 1
shift_left Word.64
store v.4 0 Int.64 Int.64
-----LINE 40 -----
load v.5 0 Int.32 Int.32
load_integer Int.32 1
subtract Int.32
store v.5 0 Int.32 Int.32
-----LINE 36 -----
. L.5 F
load_integer Int.64 0
load v.4 0 Int.64 Int.64
and Word.64
load_integer Int.64 0
if_eq Int.64 L.6 80
. L.7 F
-----LINE 43 -----
exit_proc Void
end_procedure p.7
# Main_M3
# module main body Main_M3
-----LINE 45 -----
begin_procedure p.1
load v.3 0 Int.32 Int.32
if_false Int.32 L.8 0
-----LINE 47 -----
start_call_direct p.7 0 Void
load_integer Int.64 3
pop_param Int.64
load_integer Int.32 2
pop_param Int.32
call_direct p.7 Void
. L.8 F
load_address v.2 0
exit_proc Addr
end_procedure p.1
# global constant type descriptor
declare_record -1 448 0
# global data type descriptor
declare_record -1 896 0
# module global constants
bind_segment v.1 56 8 Struct F T
begin_init v.1
# procedure names
init_chars 0 "Main_M3"
init_chars 8 "Normalize"
# procedure table
init_proc 20 p.1
init_var 24 v.1 0
init_proc 28 p.7
init_var 32 v.1 8
# file name
init_chars 40 "../src/Main.m3"
end_init v.1
# module global data
bind_segment v.2 112 8 Struct F T
begin_init v.2
init_var 0 v.1 40
init_var 20 v.1 20
init_var 36 v.2 52
init_proc 44 p.1
init_int 48 3 Int.32
init_proc 56 p.2
init_var 60 v.2 64
init_proc 68 p.3
init_var 72 v.2 76
init_proc 80 p.4
init_var 84 v.2 88
init_proc 92 p.5
init_var 96 v.2 100
init_proc 104 p.6
end_init v.2
# load map
#
#
# global data allocation for M_Main
# 0 52 4 *module info*
# 52 12 4 import Main
# 64 12 4 import Fmt
# 76 12 4 import IO
# 88 12 4 import Long
# 100 12 4 import RTHooks
# 112 0 4 *TOTAL*
#
#
# global constants for M_Main
# 0 18 4 *proc names*
# 20 20 4 *proc info*
# 40 15 1 *string*
# 56 0 4 *TOTAL*
#
end_unit
Its very similar except for using Word.64 instead of Int.64 and a couple of
other cosmetic issues.
The trouble is near label L5 where it does a load_integer of 0 instead of
the big constant.
The result of anding the zero and testing for zero is causing the loop.
Compiling this with -O also causes the backend to crash.
Both of these are on LINUXLIBC6. The AMD64 intermediate is correct. Seems
like its not parsing the
big long for some reason or else its wrapping around.
Any ideas?
Regards Peter
On Tue, May 24, 2016 at 4:40 AM, Rodney M. Bates <rodney_bates at lcwb.coop>
wrote:
>
>
>
> I did git pull and rebuilt on LINUXLIBC6. The built cm3 executable
> crashes compiling
> a very small experiment program:
>
> rodney at yellowstone:~/proj/m3/exp/FmtBug/src$ cm3-
> Segmentation fault (core dumped)
>
> m3gdb (after I built it) gives this:
>
> rodney at yellowstone:~/proj/m3/exp/FmtBug/src$ m3gdb cm3-
> GNU gdb plus Modula-3 6.4
> Copyright 2005 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you
> are
> welcome to change it and/or distribute copies of it under certain
> conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details.
> This GDB was configured as "i686-pc-linux-gnu"...Using host libthread_db
> library "/lib/tls/i686/cmov/libthread_db.so.1".
>
> (m3gdb) run
> Starting program: /usr/local/cm3-githead/bin/cm3-
> [Thread debugging using libthread_db enabled]
> [New LWP 23615]
> [New Thread -1216829744 (LWP 23615)]
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread -1216829744 (LWP 23615)]
> 0x0037c26f in siglongjmp () from /lib/tls/i686/cmov/libc.so.6
> (m3gdb) bt
> #0 0x0037c26f in siglongjmp () from /lib/tls/i686/cmov/libc.so.6
> #1 0x577b2a84 in ?? ()
> Cannot access memory at address 0xd7a0906f
> (m3gdb) quit
>
>
> stock gdb gives even less information:
>
> rodney at yellowstone:~/proj/m3/exp/FmtBug/src$ gdb cm3-
> GNU gdb (GDB) 7.1-ubuntu
> Copyright (C) 2010 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <
> http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show
> copying"
> and "show warranty" for details.
> This GDB was configured as "i486-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
> Reading symbols from /usr/local/cm3-githead/bin/cm3-...done.
> (gdb) run
> Starting program: /usr/local/cm3-githead/bin/cm3-
> [Thread debugging using libthread_db enabled]
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x0032e26f in ?? () from /lib/tls/i686/cmov/libc.so.6
> (gdb) bt
> #0 0x0032e26f in ?? () from /lib/tls/i686/cmov/libc.so.6
> #1 0xfb35d04b in ?? ()
> Cannot access memory at address 0x7bee2da0
> (gdb)
>
> Note that gdb gives a different address in the same library for the point
> of fault.
>
> m3gdb claims it's in siglongjmp. I recall there were some recent changes
> involving
> longjump.
>
>
>
>
>
>
> On 05/22/2016 09:28 PM, Peter McKinna wrote:
> > I dont know what changed but the backend is crashing on linuxlibc6 when
> compiled with -O Try compiling m3core.
> >
> > Also some of my low level tests with Long.And and Long.Shift are not
> working with
> > normal compile without the optimisations on that platform. Bit
> suspicious. I'm still investigating.
> >
> > Anyone got any clues or can replicate?
> >
> > Thanks Peter
> >
> >
> >
> >
> > _______________________________________________
> > M3devel mailing list
> > M3devel at elegosoft.com
> > https://mail.elegosoft.com/cgi-bin/mailman/listinfo/m3devel
> >
>
>
> --
> Rodney Bates
> rodney.m.bates at acm.org
> _______________________________________________
> M3devel mailing list
> M3devel at elegosoft.com
> https://mail.elegosoft.com/cgi-bin/mailman/listinfo/m3devel
>
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