[Bug tree-optimization/113673] New: [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[Bug tree-optimization/113673] New: [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

            Bug ID: 113673
           Summary: [12/13/14 Regression] ICE: verify_flow_info failed: BB
                    5 cannot throw but has an EH edge with -Os
                    -finstrument-functions -fnon-call-exceptions -ftrapv
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 57266
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57266&action=edit
reduced testcase

Compiler output:
$ x86_64-pc-linux-gnu-gcc -Os -finstrument-functions -fnon-call-exceptions
-ftrapv testcase.c 
testcase.c: In function 'ssl_scan_clienthello_tlsext_limit':
testcase.c:4:1: error: BB 5 cannot throw but has an EH edge
    4 | ssl_scan_clienthello_tlsext_limit (unsigned char *data)
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
during GIMPLE pass: bswap
testcase.c:4:1: internal compiler error: verify_flow_info failed
0xf9044e verify_flow_info()
        /repo/gcc-trunk/gcc/cfghooks.cc:287
0x13ca947 execute_function_todo
        /repo/gcc-trunk/gcc/passes.cc:2100
0x13cae7e execute_todo
        /repo/gcc-trunk/gcc/passes.cc:2142
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.

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-8635-20240130094253-g24d5e0bf19f-checking-yes-rtl-df-extra-nobootstrap-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/14.0.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--disable-bootstrap --with-cloog --with-ppl --with-isl
--build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu
--target=x86_64-pc-linux-gnu --with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r14-8635-20240130094253-g24d5e0bf19f-checking-yes-rtl-df-extra-nobootstrap-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.1 20240130 (experimental) (GCC)

[Bug tree-optimization/113673] [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu.org
   Target Milestone|---                         |12.4

[Bug tree-optimization/113673] [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-01-30

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

Here is a C++ testcase which does something similar to `-finstrument-functions`
does to the IR (`-Os -fnon-call-exceptions -ftrapv` is only needed):
```
struct s { ~s(); };
void
h (unsigned char *data, int c)
{
  s a1;
  while (c)
    {
      int m = *data++ << 8;
      m += *data++;
    }
}
```

[Bug tree-optimization/113673] [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Looks like an issue in bswap with regard to EH.

[Bug tree-optimization/113673] [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[mjires at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

Michal Jireš <mjires at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2024-01-30 00:00:00         |2024-2-8
           Keywords|needs-bisection             |
                 CC|                            |mjires at gcc dot gnu.org,
                   |                            |roger at nextmovesoftware dot com

--- Comment #3 from Michal Jireš <mjires at gcc dot gnu.org> ---
Bisected to r12-5453-ga944b5dec3adb2.

[Bug tree-optimization/113673] [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[roger at nextmovesoftware dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

--- Comment #4 from Roger Sayle <roger at nextmovesoftware dot com> ---
The identified patch implements += the same way as |=.  Presumably a version of
the test case replacing "m += *data++;" with "m |= *data++;" would be more
useful at identifying a patch that actually changed EH edges.

[Bug tree-optimization/113673] [12/13/14 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Roger Sayle from comment #4)
> The identified patch implements += the same way as |=.  Presumably a version
> of the test case replacing "m += *data++;" with "m |= *data++;" would be
> more useful at identifying a patch that actually changed EH edges.

Well + can trap on overflow with -ftrapv (and cause exceptions with
-fnon-call-exceptions) but | will not/cannot trap ...
So that patch is definitely the one which changes the EH edges.

[Bug tree-optimization/113673] [12/13/14/15 Regression] ICE: verify_flow_info failed: BB 5 cannot throw but has an EH edge with -Os -finstrument-functions -fnon-call-exceptions -ftrapv

[roger at nextmovesoftware dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113673

Roger Sayle <roger at nextmovesoftware dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |roger at nextmovesoftware dot com
             Status|NEW                         |ASSIGNED

--- Comment #6 from Roger Sayle <roger at nextmovesoftware dot com> ---
Created attachment 58051
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58051&action=edit
proposed patch

Bootstrapping and regression testing the attached patch.