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* [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes
@ 2020-07-31 17:43 dje at gcc dot gnu.org
  2020-07-31 17:44 ` [Bug bootstrap/96404] " dje at gcc dot gnu.org
                   ` (20 more replies)
  0 siblings, 21 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-07-31 17:43 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

            Bug ID: 96404
           Summary: [10 Regression] AIX Bootstrap failure with DWARF debug
                    changes
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dje at gcc dot gnu.org
  Target Milestone: ---

After the patch for debug/96383, bootstrap fails on AIX due to stage2/stage3
comparison failure.  The DWARF debugging information differs.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] AIX Bootstrap failure with DWARF debug changes
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
@ 2020-07-31 17:44 ` dje at gcc dot gnu.org
  2020-07-31 21:05 ` slyfox at gcc dot gnu.org
                   ` (19 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-07-31 17:44 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

David Edelsohn <dje at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |96383
             Target|                            |powerpc-ibm-aix*
           Severity|normal                      |blocker
                 CC|                            |rguenth at gcc dot gnu.org


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96383
[Bug 96383] [8/9/10 Regression] Full ABI information missing from GCC compiled
C

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] AIX Bootstrap failure with DWARF debug changes
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
  2020-07-31 17:44 ` [Bug bootstrap/96404] " dje at gcc dot gnu.org
@ 2020-07-31 21:05 ` slyfox at gcc dot gnu.org
  2020-07-31 21:06 ` slyfox at gcc dot gnu.org
                   ` (18 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-07-31 21:05 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

Sergei Trofimovich <slyfox at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |slyfox at gcc dot gnu.org

--- Comment #1 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
*** Bug 96405 has been marked as a duplicate of this bug. ***

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] AIX Bootstrap failure with DWARF debug changes
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
  2020-07-31 17:44 ` [Bug bootstrap/96404] " dje at gcc dot gnu.org
  2020-07-31 21:05 ` slyfox at gcc dot gnu.org
@ 2020-07-31 21:06 ` slyfox at gcc dot gnu.org
  2020-07-31 21:06 ` dje at gcc dot gnu.org
                   ` (17 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-07-31 21:06 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #2 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Seeing this as well on amd64-linux:

$ LANG=C ./xgcc -B. -v
Reading specs from ./specs
COLLECT_GCC=./xgcc
COLLECT_LTO_WRAPPER=./lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with:
/tmp/portage-tmpdir/portage/sys-devel/gcc-11.0.0_pre9999/work/gcc-11.0.0_pre9999/configure
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr
--bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/11.0.0
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.0.0/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.0.0
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.0.0/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/11.0.0/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/11.0.0/include/g++-v11
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/11.0.0/python
--enable-languages=c,c++,go,fortran --enable-obsolete --enable-secureplt
--disable-werror --with-system-zlib --enable-nls --without-included-gettext
--enable-checking=release --with-bugurl=https://bugs.gentoo.org/
--with-pkgversion='Gentoo 11.0.0_pre9999 p2, commit
8011f718e241febd6b7a9dae01cde49817f299c4' --disable-esp --enable-libstdcxx-time
--enable-shared --enable-threads=posix --enable-__cxa_atexit
--enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64
--disable-fixed-point --enable-targets=all --enable-libgomp --disable-libssp
--disable-libada --disable-systemtap --enable-valgrind-annotations
--enable-vtable-verify --without-zstd --enable-lto --with-isl
--disable-isl-version-check --enable-default-pie --enable-default-ssp
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 11.0.0 20200731 (experimental) (Gentoo 11.0.0_pre9999 p2, commit
8011f718e241febd6b7a9dae01cde49817f299c4)

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] AIX Bootstrap failure with DWARF debug changes
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (2 preceding siblings ...)
  2020-07-31 21:06 ` slyfox at gcc dot gnu.org
@ 2020-07-31 21:06 ` dje at gcc dot gnu.org
  2020-07-31 21:07 ` dje at gcc dot gnu.org
                   ` (16 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-07-31 21:06 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #3 from David Edelsohn <dje at gcc dot gnu.org> ---
This apparently occurs on x86_64-*-linux, so this is a more general problem.

It does not appear to be due to the debug patch.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] AIX Bootstrap failure with DWARF debug changes
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (3 preceding siblings ...)
  2020-07-31 21:06 ` dje at gcc dot gnu.org
@ 2020-07-31 21:07 ` dje at gcc dot gnu.org
  2020-07-31 21:13 ` [Bug bootstrap/96404] [10 Regression] Bootstrap failure slyfox at gcc dot gnu.org
                   ` (15 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-07-31 21:07 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

David Edelsohn <dje at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
             Target|powerpc-ibm-aix*            |*-*-*
   Last reconfirmed|                            |2020-07-31

--- Comment #4 from David Edelsohn <dje at gcc dot gnu.org> ---
This seems to be present for x86_64-*-linux also.

I reverted the debug change, but the failure still is present.  Continuing to
search for the offending patch.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (4 preceding siblings ...)
  2020-07-31 21:07 ` dje at gcc dot gnu.org
@ 2020-07-31 21:13 ` slyfox at gcc dot gnu.org
  2020-07-31 21:16 ` dje at gcc dot gnu.org
                   ` (14 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-07-31 21:13 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #5 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Comparing example file:

$ LANG=C cmp --ignore-initial=16 ./stage2-x86_64-pc-linux-gnu/libgomp/task.o
./stage3-x86_64-pc-linux-gnu/libgomp/task.o
./stage2-x86_64-pc-linux-gnu/libgomp/task.o
./stage3-x86_64-pc-linux-gnu/libgomp/task.o differ: char 325521, line 4234

Looks like there is slight non-determinism in .debug_loc. Don't know if it
comes from gcc or binutils. Both wibbly entries are the same symbol offset:


$ diff -U10000 <(x86_64-pc-linux-gnu-readelf -a
stage2-x86_64-pc-linux-gnu/libgomp/task.o) <(x86_64-pc-linux-gnu-readelf -a
stage3-x86_64-pc-linux-gnu/libgomp/task.o) | egrep 'section|^[-+]'

 Relocation section '.rela.debug_loc' at offset 0x36938 contains 7185 entries:
-00000000e312  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
-00000000e320  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000e312  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
+00000000e320  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000e6f5  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
-00000000e703  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000e6f5  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
+00000000e703  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000e9c4  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
-00000000e9d2  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000e9c4  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
+00000000e9d2  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000ec69  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000ec69  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000eecd  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000eecd  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000ef61  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000ef61  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000f01f  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000f01f  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-00000000f388  000200000001 R_X86_64_64       0000000000000000 .text + 66b8
+00000000f388  000200000001 R_X86_64_64       0000000000000000 .text + 66cd
-0000000112e3  000200000001 R_X86_64_64       0000000000000000 .text + 5a84
+0000000112e3  000200000001 R_X86_64_64       0000000000000000 .text + 5a79

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (5 preceding siblings ...)
  2020-07-31 21:13 ` [Bug bootstrap/96404] [10 Regression] Bootstrap failure slyfox at gcc dot gnu.org
@ 2020-07-31 21:16 ` dje at gcc dot gnu.org
  2020-07-31 21:17 ` dje at gcc dot gnu.org
                   ` (13 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-07-31 21:16 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #6 from David Edelsohn <dje at gcc dot gnu.org> ---
Created attachment 48969
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48969&action=edit
stage2 dbgcnt.s

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (6 preceding siblings ...)
  2020-07-31 21:16 ` dje at gcc dot gnu.org
@ 2020-07-31 21:17 ` dje at gcc dot gnu.org
  2020-07-31 21:25 ` slyfox at gcc dot gnu.org
                   ` (12 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-07-31 21:17 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #7 from David Edelsohn <dje at gcc dot gnu.org> ---
Created attachment 48970
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48970&action=edit
stage3 dbgcnt.s

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (7 preceding siblings ...)
  2020-07-31 21:17 ` dje at gcc dot gnu.org
@ 2020-07-31 21:25 ` slyfox at gcc dot gnu.org
  2020-07-31 21:32 ` slyfox at gcc dot gnu.org
                   ` (11 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-07-31 21:25 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #8 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Created attachment 48971
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48971&action=edit
task.S-stage2-stage3.tar.gz

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (8 preceding siblings ...)
  2020-07-31 21:25 ` slyfox at gcc dot gnu.org
@ 2020-07-31 21:32 ` slyfox at gcc dot gnu.org
  2020-08-01  1:02 ` dje at gcc dot gnu.org
                   ` (10 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-07-31 21:32 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #9 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
valgrind says there is use of uninitialized variable:

==3676055== Conditional jump or move depends on uninitialised value(s)
==3676055==    at 0xDBED3B: vt_find_locations() (var-tracking.c:7230)
==3676055==    by 0xDBF2FB: variable_tracking_main_1() (var-tracking.c:10519)
==3676055==    by 0xDBF49B: variable_tracking_main (var-tracking.c:10565)
==3676055==    by 0xDBF49B: (anonymous
namespace)::pass_variable_tracking::execute(function*) (var-tracking.c:10602)
==3676055==    by 0xA71977: execute_one_pass(opt_pass*) (passes.c:2509)
==3676055==    by 0xA7229F: execute_pass_list_1(opt_pass*) (passes.c:2597)
==3676055==    by 0xA722B1: execute_pass_list_1(opt_pass*) (passes.c:2598)
==3676055==    by 0xA722B1: execute_pass_list_1(opt_pass*) (passes.c:2598)
==3676055==    by 0xA722D8: execute_pass_list(function*, opt_pass*)
(passes.c:2608)
==3676055==    by 0x748A1D: cgraph_node::expand() (cgraphunit.c:2301)
==3676055==    by 0x749E85: expand_all_functions (cgraphunit.c:2472)
==3676055==    by 0x749E85: symbol_table::compile() [clone .part.0]
(cgraphunit.c:2835)
==3676055==    by 0x74BF22: compile (cgraphunit.c:2748)
==3676055==    by 0x74BF22: symbol_table::finalize_compilation_unit()
(cgraphunit.c:3013)
==3676055==    by 0xB35FF0: compile_file() (toplev.c:483)
==3676055==    by 0x5ED309: do_compile (toplev.c:2331)
==3676055==    by 0x5ED309: toplev::main(int, char**) (toplev.c:2470)
==3676055==    by 0x5F0FFB: main (main.c:39)
==3676055==  Uninitialised value was created by a heap allocation
==3676055==    at 0x483779F: malloc (vg_replace_malloc.c:307)
==3676055==    by 0x14EE80B: xmalloc (xmalloc.c:147)
==3676055==    by 0x14911F9: sbitmap_alloc(unsigned int) (sbitmap.c:51)
==3676055==    by 0xDBE6BA: vt_find_locations() (var-tracking.c:7097)
==3676055==    by 0xDBF2FB: variable_tracking_main_1() (var-tracking.c:10519)
==3676055==    by 0xDBF49B: variable_tracking_main (var-tracking.c:10565)
==3676055==    by 0xDBF49B: (anonymous
namespace)::pass_variable_tracking::execute(function*) (var-tracking.c:10602)
==3676055==    by 0xA71977: execute_one_pass(opt_pass*) (passes.c:2509)
==3676055==    by 0xA7229F: execute_pass_list_1(opt_pass*) (passes.c:2597)
==3676055==    by 0xA722B1: execute_pass_list_1(opt_pass*) (passes.c:2598)
==3676055==    by 0xA722B1: execute_pass_list_1(opt_pass*) (passes.c:2598)
==3676055==    by 0xA722D8: execute_pass_list(function*, opt_pass*)
(passes.c:2608)
==3676055==    by 0x748A1D: cgraph_node::expand() (cgraphunit.c:2301)
==3676055==    by 0x749E85: expand_all_functions (cgraphunit.c:2472)
==3676055==    by 0x749E85: symbol_table::compile() [clone .part.0]
(cgraphunit.c:2835)
==3676055==    by 0x74BF22: compile (cgraphunit.c:2748)
==3676055==    by 0x74BF22: symbol_table::finalize_compilation_unit()
(cgraphunit.c:3013)
==3676055==    by 0xB35FF0: compile_file() (toplev.c:483)
==3676055==    by 0x5ED309: do_compile (toplev.c:2331)
==3676055==    by 0x5ED309: toplev::main(int, char**) (toplev.c:2470)
==3676055==    by 0x5F0FFB: main (main.c:39)

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (9 preceding siblings ...)
  2020-07-31 21:32 ` slyfox at gcc dot gnu.org
@ 2020-08-01  1:02 ` dje at gcc dot gnu.org
  2020-08-01 11:34 ` dje at gcc dot gnu.org
                   ` (9 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-08-01  1:02 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #10 from David Edelsohn <dje at gcc dot gnu.org> ---
r11-2445 succeeds.  I am testing r11-2447 and then r11-2451.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (10 preceding siblings ...)
  2020-08-01  1:02 ` dje at gcc dot gnu.org
@ 2020-08-01 11:34 ` dje at gcc dot gnu.org
  2020-08-01 15:56 ` dje at gcc dot gnu.org
                   ` (8 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-08-01 11:34 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #11 from David Edelsohn <dje at gcc dot gnu.org> ---
r11-2447 fails.  Testing r11-2446.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (11 preceding siblings ...)
  2020-08-01 11:34 ` dje at gcc dot gnu.org
@ 2020-08-01 15:56 ` dje at gcc dot gnu.org
  2020-08-02  0:34 ` dje at gcc dot gnu.org
                   ` (7 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-08-01 15:56 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #12 from David Edelsohn <dje at gcc dot gnu.org> ---
r11-2446 succeeds and r11-2447 fails, so the failure (at least on AIX) is the
var-tracking dataflow patch.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (12 preceding siblings ...)
  2020-08-01 15:56 ` dje at gcc dot gnu.org
@ 2020-08-02  0:34 ` dje at gcc dot gnu.org
  2020-08-02  7:53 ` slyfox at gcc dot gnu.org
                   ` (6 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-08-02  0:34 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #13 from David Edelsohn <dje at gcc dot gnu.org> ---
The symptom I see on AIX is that the labels for DWARF variable locations differ
between stage2 and stage3 for some files.  The difference started with the
recent change to the var-tracking pass.  Once the labels diverge, the addresses
no longer match and the object file differ.

The var-tracking dump files are over 1GB with lots of address differences, but
it doesn't contain any differences in the BB dump output for vt_find_locations,
which is the function that was changed.

The assembly file differences give the appearance of an unstable sort.  The
beginning of the difference for an assembly file looks like:

--- tree-vrp.S  2020-08-01 19:42:00.000000000 -0400
+++ ../gcc/tree-vrp.S   2020-08-01 19:43:33.000000000 -0400
@@ -38428,8 +38428,8 @@
 LM..7111:
        addi 19,1,792
        li 20,1
-L..2070:
 LVL..2903:
+L..2070:
 LBE..22006:
 LBE..22005:
 LBE..22004:
@@ -38466,6 +38466,7 @@
 LM..7114:
        cmpwi 0,31,0
        beq 0,L..2043
+LVL..2904:
 LBB..22481:
 LM..7115:
 LM..7116:
@@ -38475,12 +38476,12 @@
        mr 30,31
        bl .memcpy
        nop
-LVL..2904:
+LVL..2905:
 LM..7117:
 LM..7118:
 LM..7119:
        lwz 27,8(31)
-LVL..2905:
+LVL..2906:
 LM..7120:
 LM..7121:
        lwz 9,4(27)
@@ -38489,7 +38490,7 @@
        beq 0,L..2348
 L..2044:
 LM..7123:
-LVL..2906:
+LVL..2907:
 LBE..22481:
 LBE..22508:
 LBE..22535:

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (13 preceding siblings ...)
  2020-08-02  0:34 ` dje at gcc dot gnu.org
@ 2020-08-02  7:53 ` slyfox at gcc dot gnu.org
  2020-08-02 10:56 ` slyfox at gcc dot gnu.org
                   ` (5 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-08-02  7:53 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #14 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
(In reply to Sergei Trofimovich from comment #9)
> valgrind says there is use of uninitialized variable:

I picked _gcov.c and minimized it's unstable compilation under cvise. Then
minimized it under presence of warnings related to var-tracking. Here is the
minimized example:

$ cat _gcov.c
int a;
int b(void) {
  for (;;)
    for (; a;)
      for (unsigned c; c < b; c++)
        ;
}

$ valgrind --trace-children=yes --track-origins=yes --num-callers=50 --quiet
stage3-gcc/xgcc -Bstage3-gcc -O2 -g -o _gcov-s3.S -DL_gcov -S _gcov.c

==913420== Conditional jump or move depends on uninitialised value(s)
==913420==    at 0xDBDABB: vt_find_locations() (in
/home/slyfox/tmp/portage/sys-devel/gcc-11.0.0_pre9999/work/build/stage3-gcc/cc1)
...

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (14 preceding siblings ...)
  2020-08-02  7:53 ` slyfox at gcc dot gnu.org
@ 2020-08-02 10:56 ` slyfox at gcc dot gnu.org
  2020-08-02 12:42 ` slyfox at gcc dot gnu.org
                   ` (4 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-08-02 10:56 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #15 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
(In reply to Sergei Trofimovich from comment #14)
> (In reply to Sergei Trofimovich from comment #9)
> > valgrind says there is use of uninitialized variable:
> 
> I picked _gcov.c and minimized it's unstable compilation under cvise. Then
> minimized it under presence of warnings related to var-tracking. Here is the
> minimized example:
> 
> $ cat _gcov.c
> int a;
> int b(void) {
>   for (;;)
>     for (; a;)
>       for (unsigned c; c < b; c++)
>         ;
> }
> 
> $ valgrind --trace-children=yes --track-origins=yes --num-callers=50 --quiet
> stage3-gcc/xgcc -Bstage3-gcc -O2 -g -o _gcov-s3.S -DL_gcov -S _gcov.c
> 
> ==913420== Conditional jump or move depends on uninitialised value(s)
> ==913420==    at 0xDBDABB: vt_find_locations() (in
> /home/slyfox/tmp/portage/sys-devel/gcc-11.0.0_pre9999/work/build/stage3-gcc/
> cc1)
> ...

The following patch seems to fix use of uninitialized variable:

--- a/gcc/var-tracking.c
+++ b/gcc/var-tracking.c
@@ -7089,20 +7089,21 @@ vt_find_locations (void)
   auto_vec<std::pair<int, int> > toplevel_scc_extents;
   int n = rev_post_order_and_mark_dfs_back_seme
     (cfun, single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun)), exit_bbs, true,
      rc_order, &toplevel_scc_extents);
   for (i = 0; i < n; i++)
     bb_order[rc_order[i]] = i;

   in_worklist = sbitmap_alloc (last_basic_block_for_fn (cfun));
   in_pending = sbitmap_alloc (last_basic_block_for_fn (cfun));
   bitmap_clear (in_worklist);
+  bitmap_clear (in_pending);

   /* We're performing the dataflow iteration independently over the
      toplevel SCCs plus leading non-cyclic entry blocks and separately
      over the tail.  That ensures best memory locality and the least
      number of visited blocks.  */
   unsigned extent = 0;
   int curr_start = -1;
   int curr_end = -1;
   do
     {

Don't know if the change correct or papers over the problem. Looking at the
initialization of 'in_pending' right below it does not seem to assume full
'in_pending' initialization.

I'll check if it fixes bootstrap for me.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (15 preceding siblings ...)
  2020-08-02 10:56 ` slyfox at gcc dot gnu.org
@ 2020-08-02 12:42 ` slyfox at gcc dot gnu.org
  2020-08-02 16:45 ` dje at gcc dot gnu.org
                   ` (3 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-08-02 12:42 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #16 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Sent https://gcc.gnu.org/pipermail/gcc-patches/2020-August/551174.html for
review.

> I'll check if it fixes bootstrap for me.

The patch fixed gcc bootstrap for me.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (16 preceding siblings ...)
  2020-08-02 12:42 ` slyfox at gcc dot gnu.org
@ 2020-08-02 16:45 ` dje at gcc dot gnu.org
  2020-08-02 18:37 ` cvs-commit at gcc dot gnu.org
                   ` (2 subsequent siblings)
  20 siblings, 0 replies; 22+ messages in thread
From: dje at gcc dot gnu.org @ 2020-08-02 16:45 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #17 from David Edelsohn <dje at gcc dot gnu.org> ---
The patch fixes bootstrap for AIX.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [10 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (17 preceding siblings ...)
  2020-08-02 16:45 ` dje at gcc dot gnu.org
@ 2020-08-02 18:37 ` cvs-commit at gcc dot gnu.org
  2020-08-02 18:42 ` [Bug bootstrap/96404] [11 " slyfox at gcc dot gnu.org
  2020-08-03  7:00 ` rguenth at gcc dot gnu.org
  20 siblings, 0 replies; 22+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2020-08-02 18:37 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

--- Comment #18 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Sergei Trofimovich <slyfox@gcc.gnu.org>:

https://gcc.gnu.org/g:6e46b3f3da5c03bc529b3690dd0995927feb9142

commit r11-2491-g6e46b3f3da5c03bc529b3690dd0995927feb9142
Author: Sergei Trofimovich <siarheit@google.com>
Date:   Sun Aug 2 12:03:55 2020 +0100

    var-tracking: fix uninitialised use of 'in_pending' [PR96404]

    r11-2447-g:1212cfad093 ("Improve var-tracking dataflow
    iteration order") changed 'in_pending' initialization
    from:

        in_pending = sbitmap_alloc (last_basic_block_for_fn (cfun));
        bitmap_ones (in_pending);

    to more complex partial bit population algorithm. Due to presence
    of uninitialized bits gcc started injecting extra debug entries
    in seemigly arbitrary locations and started failing stage2/stage3
    bootstrap comparison.

    valgrind detected unilitialized bits as:

      Conditional jump or move depends on uninitialised value(s)
         at 0xDBED3B: vt_find_locations() (var-tracking.c:7230)
         by 0xDBF2FB: variable_tracking_main_1() (var-tracking.c:10519)
         ...
       Uninitialised value was created by a heap allocation
         at 0x483779F: malloc (vg_replace_malloc.c:307)
         by 0x14EE80B: xmalloc (xmalloc.c:147)
         by 0x14911F9: sbitmap_alloc(unsigned int) (sbitmap.c:51)
         ...

    The fix explicitly initializes 'in_pending' bitmap with zeros.

    2020-08-02  Sergei Trofimovich  <siarheit@google.com>

    gcc/

            PR bootstrap/96404
            * var-tracking.c (vt_find_locations): Fully initialize
            all 'in_pending' bits.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [11 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (18 preceding siblings ...)
  2020-08-02 18:37 ` cvs-commit at gcc dot gnu.org
@ 2020-08-02 18:42 ` slyfox at gcc dot gnu.org
  2020-08-03  7:00 ` rguenth at gcc dot gnu.org
  20 siblings, 0 replies; 22+ messages in thread
From: slyfox at gcc dot gnu.org @ 2020-08-02 18:42 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

Sergei Trofimovich <slyfox at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
           Assignee|unassigned at gcc dot gnu.org      |slyfox at gcc dot gnu.org
            Summary|[10 Regression] Bootstrap   |[11 Regression] Bootstrap
                   |failure                     |failure
         Resolution|---                         |FIXED
   Target Milestone|---                         |11.0

--- Comment #19 from Sergei Trofimovich <slyfox at gcc dot gnu.org> ---
Should be fixed now.

I tweaked bug subject to point at gcc-11 as the only affected version (I assume
gcc-10 works).

^ permalink raw reply	[flat|nested] 22+ messages in thread

* [Bug bootstrap/96404] [11 Regression] Bootstrap failure
  2020-07-31 17:43 [Bug bootstrap/96404] New: [10 Regression] AIX Bootstrap failure with DWARF debug changes dje at gcc dot gnu.org
                   ` (19 preceding siblings ...)
  2020-08-02 18:42 ` [Bug bootstrap/96404] [11 " slyfox at gcc dot gnu.org
@ 2020-08-03  7:00 ` rguenth at gcc dot gnu.org
  20 siblings, 0 replies; 22+ messages in thread
From: rguenth at gcc dot gnu.org @ 2020-08-03  7:00 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96404

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ro at gcc dot gnu.org

--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> ---
*** Bug 96422 has been marked as a duplicate of this bug. ***

^ permalink raw reply	[flat|nested] 22+ messages in thread

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