[Bug target/94451] New: April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[Bug target/94451] New: April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

            Bug ID: 94451
           Summary: April 1st 2020 GCC does not compile spec 2017 gcc_r
                    benchmark with -O3
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: meissner at gcc dot gnu.org
  Target Milestone: ---

Created attachment 48166
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48166&action=edit
decimal64.i file that shows the bug.

I was building Spec 2017 with the current master compiler branch, and it failed
in 3 benchmarks.

I looked at the failure of the gcc_r benchmark, and I discovered that the
decimal64.c function gets a compiler error when I build a compiler with default
checks enabled.  I narrowed it down so that it fails with -O2 -fsplit-loops
-ftree-vectorize and -fgnu89-inline (the -fgnu89-inline is not needed for the
failure, but it is generally needed to compile Spec 2017).

-perch-> /opt/at13.0/bin/gdb cc1
GNU gdb (GDB) 8.3.1.20191211-git
Copyright (C) 2019 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 "powerpc64le-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from cc1...
Breakpoint 1 at 0x101dba40: file /home/meissner/fsf-src/trunk/gcc/diagnostic.c,
line 1777.
Breakpoint 2 at 0x1193e368: file /home/meissner/fsf-src/trunk/gcc/diagnostic.c,
line 1706.
Breakpoint 3 at 0x11a15fe8
Breakpoint 4 at 0x11a15fc4
File tree.h will be skipped when stepping.
File is-a.h will be skipped when stepping.
File line-map.h will be skipped when stepping.
File timevar.h will be skipped when stepping.
Function rtx_expr_list::next will be skipped when stepping.
Function rtx_expr_list::element will be skipped when stepping.
Function rtx_insn_list::next will be skipped when stepping.
Function rtx_insn_list::insn will be skipped when stepping.
Function rtx_sequence::len will be skipped when stepping.
Function rtx_sequence::element will be skipped when stepping.
Function rtx_sequence::insn will be skipped when stepping.
Function INSN_UID will be skipped when stepping.
Function PREV_INSN will be skipped when stepping.
Function SET_PREV_INSN will be skipped when stepping.
Function NEXT_INSN will be skipped when stepping.
Function SET_NEXT_INSN will be skipped when stepping.
Function BLOCK_FOR_INSN will be skipped when stepping.
Function PATTERN will be skipped when stepping.
Function INSN_LOCATION will be skipped when stepping.
Function INSN_HAS_LOCATION will be skipped when stepping.
Function JUMP_LABEL_AS_INSN will be skipped when stepping.
Successfully loaded GDB hooks for GCC
(gdb) r -O2 -fsplit-loops -ftree-vectorize -fgnu89-inline -quiet
foo-decimal64.i
Starting program: /home/meissner/fsf-build-ppc64le/trunk/gcc/cc1 -O2
-fsplit-loops -ftree-vectorize -fgnu89-inline -quiet foo-decimal64.i
decimal64.c: In function ‘decDigitsToDPD’:
decimal64.c:662:6: error: missing definition
for SSA_NAME: _292 in statement:
target_205 = _292;

Breakpoint 2, internal_error (gmsgid=0x11acd0d0 "verify_ssa failed") at
/home/meissner/fsf-src/trunk/gcc/diagnostic.c:1787
1787      global_dc->diagnostic_group_nesting_depth++;
(gdb) where
#0  internal_error (gmsgid=0x11acd0d0 "verify_ssa failed") at
/home/meissner/fsf-src/trunk/gcc/diagnostic.c:1787
#1  0x0000000010e2efac in verify_ssa (check_modified_stmt=<optimized out>,
check_ssa_operands=<optimized out>) at
/home/meissner/fsf-src/trunk/gcc/tree-ssa.c:1208
#2  0x00000000109b6ea0 in execute_function_todo (fn=0x7ffff5a41550,
data=<optimized out>) at /home/meissner/fsf-src/trunk/gcc/passes.c:1992
#3  0x00000000109b80d4 in do_per_function (callback=<optimized out>,
data=<optimized out>) at /home/meissner/fsf-src/trunk/gcc/passes.c:1640
#4  0x00000000109b82fc in execute_todo (flags=<optimized out>) at
/home/meissner/fsf-src/trunk/gcc/passes.c:2039
#5  0x00000000109bbcc4 in execute_one_pass (pass=pass@entry=<opt_pass*
0x12230e70 "vect"(166)>) at /home/meissner/fsf-src/trunk/gcc/passes.c:2539
#6  0x00000000109bca64 in execute_pass_list_1 (pass=<opt_pass* 0x12230e70
"vect"(166)>) at /home/meissner/fsf-src/trunk/gcc/passes.c:2590
#7  0x00000000109bca7c in execute_pass_list_1 (pass=<opt_pass* 0x12230680
"loop"(145)>) at /home/meissner/fsf-src/trunk/gcc/passes.c:2591
#8  0x00000000109bca7c in execute_pass_list_1 (pass=<opt_pass* 0x1222f310
"*all_optimizations"(-1)>) at /home/meissner/fsf-src/trunk/gcc/passes.c:2591
#9  0x00000000109bcb08 in execute_pass_list (fn=<optimized out>,
pass=<optimized out>) at /home/meissner/fsf-src/trunk/gcc/passes.c:2601
#10 0x0000000010474e00 in cgraph_node::expand (this=<cgraph_node * const
0x7ffff59c2d00 "decDigitsToDPD"/37>) at
/home/meissner/fsf-src/trunk/gcc/context.h:48
#11 0x000000001047689c in expand_all_functions () at
/home/meissner/fsf-src/trunk/gcc/cgraphunit.c:2470
#12 symbol_table::compile (this=this@entry=0x7ffff5780000) at
/home/meissner/fsf-src/trunk/gcc/cgraphunit.c:2820
#13 0x000000001047a654 in symbol_table::compile (this=0x7ffff5780000) at
/home/meissner/fsf-src/trunk/gcc/cgraphunit.c:3000
#14 symbol_table::finalize_compilation_unit (this=0x7ffff5780000) at
/home/meissner/fsf-src/trunk/gcc/cgraphunit.c:3000
#15 0x0000000010afb2b8 in compile_file () at
/home/meissner/fsf-src/trunk/gcc/toplev.c:483
#16 0x00000000101de57c in do_compile () at
/home/meissner/fsf-src/trunk/gcc/toplev.c:2273
#17 toplev::main (this=0x7fffffffdc40, argc=<optimized out>, argv=<optimized
out>) at /home/meissner/fsf-src/trunk/gcc/toplev.c:2412
#18 0x00000000101e0718 in main (argc=<optimized out>, argv=0x7fffffffe068) at
/home/meissner/fsf-src/trunk/gcc/main.c:39

I did a pull later in the day, and I got Peter Bergner's lower-subreg patches,
but it did not help with the failure.  The git hash for the branch is
918b89b7623b6c42b09f37b7e3ef807d1abbabb8.

I fell back to the version of the compiler I pulled on March 27th with a git
hash of 71d69548a1b2c85220ac6354564fd272beb9263f, and it builds Spec 2017 gcc_r
fine with my normal options (-Ofast -mveclibabi=mass -mrecip, etc.).

I did a diff of the gcc/config/rs6000 files, and the following 3 files were
modified:
gcc/config/rs6000/rs6000-call.c
gcc/config/rs6000/rs6000.c
gcc/config/rs6000/rs6000.md

However, if I replace these files in the 4/1 compiler, it still fails.  So it
does not appear to be due to PowerPC specific changes.

I'm including an attachment of decimal64.i that shows the error with the -O2
-fsplit-loops -ftree-vectorize -fgnu89-inline options.

[Bug target/94451] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Michael Meissner <meissner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amodra at gcc dot gnu.org,
                   |                            |bergner at gcc dot gnu.org,
                   |                            |dje at gcc dot gnu.org,
                   |                            |meissner at gcc dot gnu.org,
                   |                            |segher at gcc dot gnu.org,
                   |                            |wschmidt at gcc dot gnu.org
           Severity|normal                      |critical
               Host|                            |powerpc64le-gnu-linux
              Build|                            |powerpc64le-gnu-linux
             Target|                            |powerpc64le-gnu-linux
           Priority|P3                          |P2

--- Comment #1 from Michael Meissner <meissner at gcc dot gnu.org> ---
I built the compiler on Ubuntu 18.04 on a little endian power9 system using
--with-cpu=power9.  I used the Advance Toolchain AT13 compiler to build the
compiler.  I did not bootstrap the compiler.

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |tree-optimization
           Keywords|                            |ice-on-valid-code
   Target Milestone|---                         |10.0
            Summary|April 1st 2020 GCC does not |[10 Regression] April 1st
                   |compile spec 2017 gcc_r     |2020 GCC does not compile
                   |benchmark with -O3          |spec 2017 gcc_r benchmark
                   |                            |with -O3

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Maybe:
g:f14b41d27124601284347a10d496362c8b4b8e1c
or
g:8d689cf43b501a2f5c077389adbb6d2bfa530ca9

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[linkw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Kewen Lin <linkw at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |linkw at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |linkw at gcc dot gnu.org
   Last reconfirmed|                            |2020-04-02
     Ever confirmed|0                           |1

--- Comment #3 from Kewen Lin <linkw at gcc dot gnu.org> ---
Thanks for reporting this, Mike.  It looks duplicated of pr94443.

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Segher Boessenkool <segher at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P2                          |P1

--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> ---
powerpc*-linux is a primary platform, so anything "critical" is a P1.

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marxin at gcc dot gnu.org
         Resolution|---                         |DUPLICATE
             Status|ASSIGNED                    |RESOLVED

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
Dup.

*** This bug has been marked as a duplicate of bug 94443 ***

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[linkw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Kewen Lin <linkw at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|DUPLICATE                   |FIXED

--- Comment #6 from Kewen Lin <linkw at gcc dot gnu.org> ---
Reproduced and verified with the proposed fix in pr94443, sorry for the
trouble.

[Bug tree-optimization/94451] [10 Regression] April 1st 2020 GCC does not compile spec 2017 gcc_r benchmark with -O3

[linkw at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94451

Kewen Lin <linkw at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|FIXED                       |DUPLICATE

--- Comment #7 from Kewen Lin <linkw at gcc dot gnu.org> ---
Correct the status, looks updated mistakenly somehow.

*** This bug has been marked as a duplicate of bug 94443 ***