[Bug rtl-optimization/100647] New: ICE during sms pass

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100647

            Bug ID: 100647
           Summary: ICE during sms pass
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kito at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-linux-gnu
            Target: riscv64-unknown-elf

Flags: -Ofast -fno-gcse -fmodulo-sched -freorder-blocks-and-partition
-fno-tree-dce -march=rv64gc -mabi=lp64 

Testcase:

char c;
char *d;
char *e();
char *f(char *h) {
  int a = *h;
  return *h == 7 ? h : h + a;
}
char i() {
  char *g, *b;
  g = e();
  for (; g; b = f(b))
    if (c)
      *d = 0;
  return 0;
}


ICE Message:

during RTL pass: sms
sms.crash.c: In function 'i':
sms.crash.c:15:1: internal compiler error: in
cfg_layout_redirect_edge_and_branch_force, at cfgrtl.c:4651
   15 | }
      | ^
0x82a8a8 cfg_layout_redirect_edge_and_branch_force
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/cfgrtl.c:4651
0x8102d3 redirect_edge_and_branch_force(edge_def*, basic_block_def*)
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/cfghooks.c:490
0x810de5 make_forwarder_block(basic_block_def*, bool (*)(edge_def*), void
(*)(basic_block_def*))
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/cfghooks.c:903
0x81a88d merge_latch_edges
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/cfgloop.c:780
0x81a88d disambiguate_multiple_latches
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/cfgloop.c:831
0x81a88d disambiguate_loops_with_multiple_latches()
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/cfgloop.c:844
0xb35484 apply_loop_flags
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/loop-init.c:55
0xb3605c loop_optimizer_init(unsigned int)
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/loop-init.c:124
0x15b8039 sms_schedule
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/modulo-sched.c:1362
0x15bac1f execute
        ../../../../riscv-gnu-toolchain-trunk/riscv-gcc/gcc/modulo-sched.c:3359
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.


ICE version:
Trunk, 11, 10

Note:
Work with GCC 9