[Bug tree-optimization/82875] New: ICE at -Os on valid code on x86_64-linux-gnu: in find_widening_optab_handler_and_mode, at optabs-query.c:414

[helloqirun at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82875

            Bug ID: 82875
           Summary: ICE at -Os on valid code on x86_64-linux-gnu: in
                    find_widening_optab_handler_and_mode, at
                    optabs-query.c:414
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: helloqirun at gmail dot com
  Target Milestone: ---

It happens at -Os and in 32-bit mode only.

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/8.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 8.0.0 20171106 (experimental) [trunk revision 254453] (GCC)



$ gcc-trunk -m32 -Os abc.c
during RTL pass: expand
abc.c: In function ‘fn1’:
abc.c:15:25: internal compiler error: in find_widening_optab_handler_and_mode,
at optabs-query.c:414
       d ? (a %= c) * (e *= a ? f : b) : 0;
                         ^~
0xb9b215 find_widening_optab_handler_and_mode(optab_tag, machine_mode,
machine_mode, machine_mode*)
        ../../gcc/gcc/optabs-query.c:414
0xb8e9da expand_binop(machine_mode, optab_tag, rtx_def*, rtx_def*, rtx_def*,
int, optab_methods)
        ../../gcc/gcc/optabs.c:1152
0xb91fc0 expand_doubleword_mult
        ../../gcc/gcc/optabs.c:865
0xb8fbc8 expand_binop(machine_mode, optab_tag, rtx_def*, rtx_def*, rtx_def*,
int, optab_methods)
        ../../gcc/gcc/optabs.c:1705
0x966155 expand_mult(machine_mode, rtx_def*, rtx_def*, rtx_def*, int)
        ../../gcc/gcc/expmed.c:3427
0x98b314 expand_expr_real_2(separate_ops*, rtx_def*, machine_mode,
expand_modifier)
        ../../gcc/gcc/expr.c:8802
0x865371 expand_gimple_stmt_1
        ../../gcc/gcc/cfgexpand.c:3712
0x865371 expand_gimple_stmt
        ../../gcc/gcc/cfgexpand.c:3773
0x8669d8 expand_gimple_basic_block
        ../../gcc/gcc/cfgexpand.c:5774
0x86b756 execute
        ../../gcc/gcc/cfgexpand.c:6375
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.


$ cat abc.c
char a;
unsigned b;
long c, d;
long long e;
void fn1() {
  short f = a = 6;
  for (; 4 <= 3;)
    for (; a <= 7;) {
      for (;;)
        ;
    l1:
      for (; c <= 73;)
        ;
      e = 20;
      d ? (a %= c) * (e *= a ? f : b) : 0;
    }
  goto l1;
}