[Bug tree-optimization/115220] [15 Regression] RISC-V: newlib targets ICE during sink pass triggered in verify_ssa

["law at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115220

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |law at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
   Last reconfirmed|                            |2024-05-25
             Target|riscv                       |riscv,fr30

--- Comment #5 from Jeffrey A. Law <law at gcc dot gnu.org> ---
It's a generic problem.  Almost certainly caused by the recent changes to the
sinking code.

It can be triggered (for example) on the fr30-elf port with -Os on this trivial
testcase:


extern char **environ;
static char ***p_environ = &environ;
int
_setenv_r (const char *name, const char *value)
{
  register char *C;
  int offset;
  for (C = (*p_environ)[offset]; (*C = *name++) && *C != '='; ++C);
  for (*C++ = '='; (*C++ = *value++) != 0;);


  return 0;
}