[Bug middle-end/113636] New: internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[Bug middle-end/113636] New: internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[toon at moene dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

            Bug ID: 113636
           Summary: internal compiler error: in dead_debug_global_find, at
                    valtrack.cc:275
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: toon at moene dot org
  Target Milestone: ---

A build + test run [r14-8465] on aarch64-linux-gnu draws the following ICE
while compiling math/cmplx:

during RTL pass: sched1
cmath_test.go: In function 'math/cmplx.BenchmarkCos':
cmath_test.go:1520:1: internal compiler error: in dead_debug_global_find, at
valtrack.cc:275
 1520 | func BenchmarkCos(b *testing.B) {
      | ^
0x131ce17 dead_debug_global_find
        /home/toon/compilers/gcc/gcc/valtrack.cc:275
0x131ce17 dead_debug_global_find
        /home/toon/compilers/gcc/gcc/valtrack.cc:269
0x131cef3 dead_debug_global_replace_temp
        /home/toon/compilers/gcc/gcc/valtrack.cc:321
0x131df33 dead_debug_promote_uses
        /home/toon/compilers/gcc/gcc/valtrack.cc:450
0x131df33 dead_debug_local_finish(dead_debug_local*, bitmap_head*)
        /home/toon/compilers/gcc/gcc/valtrack.cc:487
0x1d777eb dce_process_block
        /home/toon/compilers/gcc/gcc/dce.cc:1060
0x1d777eb fast_dce
        /home/toon/compilers/gcc/gcc/dce.cc:1128
0x1d77d17 rest_of_handle_fast_dce
        /home/toon/compilers/gcc/gcc/dce.cc:1194
0x1d77d17 run_fast_df_dce()
        /home/toon/compilers/gcc/gcc/dce.cc:1242
0xa6c8e7 df_lr_finalize
        /home/toon/compilers/gcc/gcc/df-problems.cc:1065
0xa6585f df_analyze_problem(dataflow*, bitmap_head*, int*, int)
        /home/toon/compilers/gcc/gcc/df-core.cc:1190
0xa658ff df_analyze_1
        /home/toon/compilers/gcc/gcc/df-core.cc:1235
0x1e5574b sched_init()
        /home/toon/compilers/gcc/gcc/haifa-sched.cc:7348
0x1e570e7 haifa_sched_init()
        /home/toon/compilers/gcc/gcc/haifa-sched.cc:7372
0xf38a4f schedule_insns()
        /home/toon/compilers/gcc/gcc/sched-rgn.cc:3517
0xf39157 schedule_insns()
        /home/toon/compilers/gcc/gcc/sched-rgn.cc:3511
0xf39157 rest_of_handle_sched
        /home/toon/compilers/gcc/gcc/sched-rgn.cc:3729
0xf39157 execute
        /home/toon/compilers/gcc/gcc/sched-rgn.cc:3839
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
FAIL: math/cmplx

The build was started with the following system compiler:

$ echo | gcc -### -E - -march=native -mtune=native
Using built-in specs.
COLLECT_GCC=gcc
OFFLOAD_TARGET_NAMES=nvptx-none
OFFLOAD_TARGET_DEFAULT=1
Target: aarch64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 13.2.0-9'
--with-bugurl=file:///usr/share/doc/gcc-13/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-13
--program-prefix=aarch64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/libexec --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-libquadmath --disable-libquadmath-support --enable-plugin
--enable-default-pie --with-system-zlib --enable-libphobos-checking=release
--with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch
--enable-fix-cortex-a53-843419 --disable-werror
--enable-offload-targets=nvptx-none=/build/reproducible-path/gcc-13-13.2.0/debian/tmp-nvptx/usr
--enable-offload-defaulted --without-cuda-driver --enable-checking=release
--build=aarch64-linux-gnu --host=aarch64-linux-gnu --target=aarch64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-serialization=4
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 13.2.0 (Debian 13.2.0-9) 
COLLECT_GCC_OPTIONS='-E'   '-mlittle-endian' '-mabi=lp64' '-mtune=thunderxt88'
 /usr/libexec/gcc/aarch64-linux-gnu/13/cc1 -E -quiet -imultiarch
aarch64-linux-gnu - -mlittle-endian "-mabi=lp64" "-mtune=thunderxt88"
-fasynchronous-unwind-tables -dumpbase -
COMPILER_PATH=/usr/libexec/gcc/aarch64-linux-gnu/13/:/usr/libexec/gcc/aarch64-linux-gnu/13/:/usr/libexec/gcc/aarch64-linux-gnu/:/usr/lib/gcc/aarch64-linux-gnu/13/:/usr/lib/gcc/aarch64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/aarch64-linux-gnu/13/:/usr/lib/gcc/aarch64-linux-gnu/13/../../../aarch64-linux-gnu/:/usr/lib/gcc/aarch64-linux-gnu/13/../../../../lib/:/lib/aarch64-linux-gnu/:/lib/../lib/:/usr/lib/aarch64-linux-gnu/:/usr/lib/../lib/:/usr/lib/gcc/aarch64-linux-gnu/13/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-E'   '-mlittle-endian' '-mabi=lp64' '-mtune=thunderxt88'

using these configure flags:

Compiler version: 14.0.1 20240127 (experimental) [master r14-8465-g5200ef26ac1]
(GCC) 
Platform: aarch64-unknown-linux-gnu
configure flags: --prefix=/home/toon/compilers/install/gcc --with-gnu-as
--with-gnu-ld --enable-languages=all --disable-multilib --disable-nls

CPU information:

$ cat /proc/cpuinfo
processor       : 0
BogoMIPS        : 200.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x43
CPU architecture: 8
CPU variant     : 0x1
CPU part        : 0x0a1
CPU revision    : 1
....
processor       : 47
BogoMIPS        : 200.00
Features        : fp asimd evtstrm aes pmull sha1 sha2 crc32 cpuid
CPU implementer : 0x43
CPU architecture: 8
CPU variant     : 0x1
CPU part        : 0x0a1
CPU revision    : 1

Link to the test summary:

https://gcc.gnu.org/pipermail/gcc-testresults/2024-January/806431.html

[Bug debug/113636] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |aarch64-linux-gnu

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I can reproduce this with a cross to aarch64-linux-gnu too.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|internal compiler error: in |[14 Regression] internal
                   |dead_debug_global_find, at  |compiler error: in
                   |valtrack.cc:275             |dead_debug_global_find, at
                   |                            |valtrack.cc:275
   Target Milestone|---                         |14.0

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
It has been failing since at least `Wed Dec 13 06:06:19 UTC 2023` for me.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Started between r14-5889-c9d691a7daa162d6d2092 and r14-6443-g3e93a3f09dc I
think.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Just FYI (just recording on how to reproduce it once the build is finished,
needed to modify some scripts to get the command line out in the first place):

cd /home/apinski/src/upstream-full-cross/gcc/libgo/go/math/cmplx

/home/apinski/src/upstream-full-cross/gcc/objdir-stage2/./gcc/gccgo
-B/home/apinski/src/upstream-full-cross/gcc/objdir-stage2/./gcc/
-B/home/apinski/src/upstream-full-cross/install/aarch64-linux-gnu/bin/
-B/home/apinski/src/upstream-full-cross/install/aarch64-linux-gnu/lib/ -isystem
/home/apinski/src/upstream-full-cross/install/aarch64-linux-gnu/include
-isystem
/home/apinski/src/upstream-full-cross/install/aarch64-linux-gnu/sys-include -g
-O2 -L
/home/apinski/src/upstream-full-cross/gcc/objdir-stage2/aarch64-linux-gnu/libgo
-L
/home/apinski/src/upstream-full-cross/gcc/objdir-stage2/aarch64-linux-gnu/libgo/.libs
-g -fgo-pkgpath=math/cmplx -c -I . -fno-toplevel-reorder -o _gotest_.o
cmath_test.go huge_test.go abs.go asin.go conj.go exp.go isinf.go isnan.go
log.go phase.go polar.go pow.go rect.go sin.go sqrt.go tan.go

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection,
                   |                            |needs-reduction

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Trying to reduce this slightly.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 57248
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57248&action=edit
Reduced so far

But this might still need some external modules, need to understand that ...

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

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

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

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks like it is early RA which exposing/causing this.

Adding `-mearly-ra=none` to the command line causes the ICE to go away.

I tried to create a C testcase but I am unable to so far. Plus it requires
debugging info so it is harder to recreate with inlining and such.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[claudio.bantaloukas at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

Claudio Bantaloukas <claudio.bantaloukas at arm dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |claudio.bantaloukas at arm dot com

--- Comment #8 from Claudio Bantaloukas <claudio.bantaloukas at arm dot com> ---
Created attachment 57250
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57250&action=edit
Further reduction

Further reduced test case

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275

[claudio.bantaloukas at arm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

--- Comment #9 from Claudio Bantaloukas <claudio.bantaloukas at arm dot com> ---
git bisect "gccgo -g -O3 -mtune=thunderxt88 -c -o __case.o case.go" starting
with $(git merge-base origin/releases/gcc-13 origin/trunk) as a first good
commit points at [9f0f7d802482a8958d6cdc72f1fe0c8549db2182] aarch64: Add an
early RA for strided registers

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275 since r14-6290-g9f0f7d802482a8

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

Richard Sandiford <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1
           Assignee|unassigned at gcc dot gnu.org      |rsandifo at gcc dot gnu.org
   Last reconfirmed|                            |2024-01-29

--- Comment #10 from Richard Sandiford <rsandifo at gcc dot gnu.org> ---
Mine.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275 since r14-6290-g9f0f7d802482a8

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

--- Comment #11 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Richard Sandiford <rsandifo@gcc.gnu.org>:

https://gcc.gnu.org/g:aeec7d87a28ac80c64ebfa88cef3dccee3ba8efc

commit r14-8518-gaeec7d87a28ac80c64ebfa88cef3dccee3ba8efc
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Tue Jan 30 09:30:35 2024 +0000

    aarch64: Handle debug references to removed registers [PR113636]

    In this PR, we entered early-ra with quite a bit of dead code.
    The code was duly removed (to avoid wasting registers), but there
    was a dangling reference in debug instructions, which caused an
    ICE later.

    Fixed by resetting a debug instruction if it references a register
    that is no longer needed by non-debug instructions.

    gcc/
            PR target/113636
            * config/aarch64/aarch64-early-ra.cc (early_ra::replace_regs): Take
            the containing insn as an extra parameter.  Reset debug
instructions
            if they reference a register that is no longer used by real insns.
            (early_ra::apply_allocation): Update calls accordingly.

    gcc/testsuite/
            PR target/113636
            * go.dg/pr113636.go: New test.

[Bug debug/113636] [14 Regression] internal compiler error: in dead_debug_global_find, at valtrack.cc:275 since r14-6290-g9f0f7d802482a8

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113636

Richard Sandiford <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #12 from Richard Sandiford <rsandifo at gcc dot gnu.org> ---
Fixed.  Thanks for the report and help with reproducing.