[Bug target/101177] New: sh3: internal compiler error: Illegal instruction

[Bug target/101177] New: sh3: internal compiler error: Illegal instruction

[roland.illig at gmx dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

            Bug ID: 101177
           Summary: sh3: internal compiler error: Illegal instruction
           Product: gcc
           Version: 9.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: roland.illig at gmx dot de
  Target Milestone: ---

$ cat lex.c
int
lex_input(void);

int
lex_character_constant(void);

int
lex_character_constant(void)
{
        int c = lex_input();
        if (c == 7)
                return c;
        c &= 255;
        return c == 0 ? -1 : c;
}

$ /home/rillig/builds/sh3-tools/bin/sh--netbsdelf-gcc --version
sh--netbsdelf-gcc (NetBSD nb1 20200907) 9.3.0
Copyright (C) 2019 Free Software Foundation, Inc.

$ /home/rillig/builds/sh3-tools/bin/sh--netbsdelf-gcc lex.c -O1
sh--netbsdelf-gcc: internal compiler error: Illegal instruction signal
terminated program cc1

$ gdb --args /home/rillig/builds/sh3-tools/libexec/gcc/sh--netbsdelf/9.3.0/cc1
lex.c -O1
(gdb) r
(gdb) bt
#0  0x0000000000675ddc in df_ref_create_structure(df_ref_class,
df_collection_rec*, rtx_def*, rtx_def**, basic_block_def*, df_insn_info*,
df_ref_type, int) ()
#1  0x0000000000676b90 in df_ref_record(df_ref_class, df_collection_rec*,
rtx_def*, rtx_def**, basic_block_def*, df_insn_info*, df_ref_type, int) ()
#2  0x0000000000676dc9 in df_uses_record(df_collection_rec*, rtx_def**,
df_ref_type, basic_block_def*, df_insn_info*, int) ()
#3  0x0000000000676e91 in df_uses_record(df_collection_rec*, rtx_def**,
df_ref_type, basic_block_def*, df_insn_info*, int) ()
#4  0x0000000000678274 in df_insn_refs_collect(df_collection_rec*,
basic_block_def*, df_insn_info*) ()
#5  0x000000000067b617 in df_insn_rescan(rtx_insn*) ()
#6  0x00000000006dc3a1 in emit_pattern_after_noloc(rtx_def*, rtx_insn*,
basic_block_def*, rtx_insn* (*)(rtx_def*)) ()
#7  0x00000000006dc3d3 in emit_pattern_after_setloc(rtx_def*, rtx_insn*,
unsigned int, rtx_insn* (*)(rtx_def*)) ()
#8  0x00000000006dcc12 in emit_insn_after_setloc(rtx_def*, rtx_insn*, unsigned
int) ()
#9  0x00000000006dce92 in try_split(rtx_def*, rtx_insn*, int) ()
#10 0x00000000006dd275 in try_split(rtx_def*, rtx_insn*, int) ()
#11 0x00000000006dd275 in try_split(rtx_def*, rtx_insn*, int) ()
...
#1979 0x00000000006dd275 in try_split(rtx_def*, rtx_insn*, int) ()
#1980 0x00000000006dd275 in try_split(rtx_def*, rtx_insn*, int) ()
#1981 0x0000000000905d33 in split_insn(rtx_insn*) ()
#1982 0x0000000000909c96 in split_all_insns() ()
#1983 0x0000000000909dc3 in (anonymous
namespace)::pass_split_all_insns::execute(function*) ()
#1984 0x00000000008d2044 in execute_one_pass(opt_pass*) ()
#1985 0x00000000008d29a8 in execute_pass_list_1(opt_pass*) ()
#1986 0x00000000008d29ba in execute_pass_list_1(opt_pass*) ()
#1987 0x00000000008d29e0 in execute_pass_list(function*, opt_pass*) ()
#1988 0x000000000064fe9f in cgraph_node::expand() ()
#1989 0x0000000000651375 in symbol_table::compile() ()
#1990 0x0000000000652c7f in symbol_table::finalize_compilation_unit() ()
#1991 0x000000000098b57d in compile_file() ()
#1992 0x000000000098da13 in toplev::main(int, char**) ()
#1993 0x0000000000f36e1c in main ()

The code is extracted from:
https://github.com/NetBSD/src/blob/3f158578dbda380f096b448cf750251299159488/usr.bin/xlint/lint1/lex.c

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[gcc_bugzilla at foobar dot franken.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

Harold Gutch <gcc_bugzilla at foobar dot franken.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gcc_bugzilla at foobar dot franken
                   |                            |.de

--- Comment #1 from Harold Gutch <gcc_bugzilla at foobar dot franken.de> ---
(In reply to Roland Illig from comment #0)
> $ cat lex.c
> int
> lex_input(void);
> 
> int
> lex_character_constant(void);
> 
> int
> lex_character_constant(void)
> {
>         int c = lex_input();
>         if (c == 7)
>                 return c;
>         c &= 255;
>         return c == 0 ? -1 : c;
> }
> 
> $ /home/rillig/builds/sh3-tools/bin/sh--netbsdelf-gcc --version
> sh--netbsdelf-gcc (NetBSD nb1 20200907) 9.3.0
> Copyright (C) 2019 Free Software Foundation, Inc.
> 
> $ /home/rillig/builds/sh3-tools/bin/sh--netbsdelf-gcc lex.c -O1
> sh--netbsdelf-gcc: internal compiler error: Illegal instruction signal
> terminated program cc1

This is not specific to the NetBSD cross toolchain, this also happens with a
vanilla GCC built on Linux, verified with both 9.3.0 and git head.

I bisected this to commit 91f66e78cc141da77ff9e0e3c8519e1af3f26c07 ,
https://gcc.gnu.org/git/?p=gcc.git;a=blobdiff;f=gcc/config/sh/sh.md;h=e19e977087db4d5231f2276af53a42ee82bd50de;hp=2645fca47383c965715555f4750033f893ad869e;hb=91f66e78cc141da77ff9e0e3c8519e1af3f26c07;hpb=8faa81184f856447084a9ee41a63fc4be6bca572

I cannot claim to understand the details of this patch, but note that in the
second part of the diff the condition gets inverted.  Take for this the simple
case of SUBREG_P(reg) being false, then this changed from

  if (find_regno_note (curr_insn, REG_DEAD, REGNO (operands[0])) == NULL_RTX)

to

  if (find_regno_note (curr_insn, REG_DEAD, REGNO (operands[0])) != NULL_RTX)

After changing this back to "==", the test case passes for me again, and I can
run a full build of NetBSD/Dreamcast (SH3).  I have not verified however if the
built system works correctly.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[gcc_bugzilla at foobar dot franken.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #2 from Harold Gutch <gcc_bugzilla at foobar dot franken.de> ---
Created attachment 51098
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51098&action=edit
revert the change of condition

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[gcc_bugzilla at foobar dot franken.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #3 from Harold Gutch <gcc_bugzilla at foobar dot franken.de> ---
With my patch, the NetBSD/dreamcast build successfully reaches multiuser.

Also, note that the rest of the commit looks very much like what the commit
message described, but I don't see anything that might explain the inversion in
the comparison, leading me to believe that this was a typo that managed to
sneak in by accident.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

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

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

--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> ---
(In reply to Harold Gutch from comment #1)
> I cannot claim to understand the details of this patch, but note that in the
> second part of the diff the condition gets inverted.

Yes, that looks like a clear mistake.  I don't know why I did that, perhaps
at first I flipped the control flow there?  Who knows.  Sorry for it anyway!

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[glaubitz at physik dot fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |glaubitz at physik dot fu-berlin.d
                   |                            |e

--- Comment #5 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
(In reply to Segher Boessenkool from comment #4)
> (In reply to Harold Gutch from comment #1)
> > I cannot claim to understand the details of this patch, but note that in the
> > second part of the diff the condition gets inverted.
> 
> Yes, that looks like a clear mistake.  I don't know why I did that, perhaps
> at first I flipped the control flow there?  Who knows.  Sorry for it anyway!

Was this ever fixed?

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[glaubitz at physik dot fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #6 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
@Segher: In case it's trivial to fix, could you get this fixed or revert the
patch?

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Oleg Endo <olegendo@gcc.gnu.org>:

https://gcc.gnu.org/g:1d0ca7ecd4f4dfef4145ad3a41fa0a72c8b19697

commit r14-4782-g1d0ca7ecd4f4dfef4145ad3a41fa0a72c8b19697
Author: Oleg Endo <olegendo@gcc.gnu.org>
Date:   Fri Oct 20 18:48:34 2023 +0900

    SH: Fix PR 101177

    Fix accidentally inverted comparison.

    gcc/ChangeLog:

            PR target/101177
            * config/sh/sh.md (unnamed split pattern): Fix comparison of
            find_regno_note result.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Oleg Endo
<olegendo@gcc.gnu.org>:

https://gcc.gnu.org/g:3ce4e99303d01d348229cca22bf8d3dd63004e01

commit r13-7966-g3ce4e99303d01d348229cca22bf8d3dd63004e01
Author: Oleg Endo <olegendo@gcc.gnu.org>
Date:   Fri Oct 20 18:48:34 2023 +0900

    SH: Fix PR 101177

    Fix accidentally inverted comparison.

    gcc/ChangeLog:

            PR target/101177
            * config/sh/sh.md (unnamed split pattern): Fix comparison of
            find_regno_note result.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-12 branch has been updated by Oleg Endo
<olegendo@gcc.gnu.org>:

https://gcc.gnu.org/g:21ce4f97b2c158778fbf96858e7e589ad648b3c8

commit r12-9932-g21ce4f97b2c158778fbf96858e7e589ad648b3c8
Author: Oleg Endo <olegendo@gcc.gnu.org>
Date:   Fri Oct 20 18:48:34 2023 +0900

    SH: Fix PR 101177

    Fix accidentally inverted comparison.

    gcc/ChangeLog:

            PR target/101177
            * config/sh/sh.md (unnamed split pattern): Fix comparison of
            find_regno_note result.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Oleg Endo
<olegendo@gcc.gnu.org>:

https://gcc.gnu.org/g:e784ba28ae0214b02ae45734d5106ca421711a8a

commit r11-11069-ge784ba28ae0214b02ae45734d5106ca421711a8a
Author: Oleg Endo <olegendo@gcc.gnu.org>
Date:   Fri Oct 20 18:48:34 2023 +0900

    SH: Fix PR 101177

    Fix accidentally inverted comparison.

    gcc/ChangeLog:

            PR target/101177
            * config/sh/sh.md (unnamed split pattern): Fix comparison of
            find_regno_note result.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

Oleg Endo <olegendo at gcc dot gnu.org> changed:

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

--- Comment #11 from Oleg Endo <olegendo at gcc dot gnu.org> ---
(In reply to John Paul Adrian Glaubitz from comment #5)
> (In reply to Segher Boessenkool from comment #4)
> > (In reply to Harold Gutch from comment #1)
> > > I cannot claim to understand the details of this patch, but note that in the
> > > second part of the diff the condition gets inverted.
> > 
> > Yes, that looks like a clear mistake.  I don't know why I did that, perhaps
> > at first I flipped the control flow there?  Who knows.  Sorry for it anyway!
> 
> Was this ever fixed?

It should be now.

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[glaubitz at physik dot fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #12 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
(In reply to Oleg Endo from comment #11)
> (In reply to John Paul Adrian Glaubitz from comment #5)
> > (In reply to Segher Boessenkool from comment #4)
> > > (In reply to Harold Gutch from comment #1)
> > > > I cannot claim to understand the details of this patch, but note that in the
> > > > second part of the diff the condition gets inverted.
> > > 
> > > Yes, that looks like a clear mistake.  I don't know why I did that, perhaps
> > > at first I flipped the control flow there?  Who knows.  Sorry for it anyway!
> > 
> > Was this ever fixed?
> 
> It should be now.

That was super-fast! Thanks a lot!

[Bug target/101177] sh3: internal compiler error: Illegal instruction

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101177

--- Comment #13 from Oleg Endo <olegendo at gcc dot gnu.org> ---
(In reply to John Paul Adrian Glaubitz from comment #12)
> 
> That was super-fast! Thanks a lot!

Not really. ~2 years from patch to commit.  Sorry about that.