https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121580
Bug ID: 121580
Summary: [ICE] internal compiler error: in fold_convert_loc, at
fold-const.cc:2670
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: njuwy at smail dot nju.edu.cn
Target Milestone: ---
Compiler Explorer: https://godbolt.org/z/3r3MxTdET
The crash triggering program (compile with `gcc-16 -O0`):
```
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
typedef typeof(nullptr) nullptr_t;
static long double process_array(int *data, size_t len, nullptr_t np) {
size_t i = 0;
long double acc = 0.0l;
int threshold = len > 5 ? data[5] : 0;
while (i < len) {
if (np != nullptr) {
acc += (long double)(data[i]);
if (acc > threshold) {
acc = (acc < 100.0l) ? acc : 100.0l;
for (size_t j = i + 1; j < len && j < i + 3; ++j) {
data[j] ^= (int)(acc / 10.0l);
}
threshold = (int)(acc / 2.0l);
}
}
i += (acc < 50.0l) ? 1 : 2;
}
printf("Final accumulator: %.2Lf\n", acc);
return acc;
}
int main(void) {
int values[] = {10, 20, 5, 30, 40, 15, 25};
size_t n = sizeof(values) / sizeof(values[0]);
nullptr_t nullp = nullptr;
process_array(values, n, nullp);
if (nullp == nullptr) {
puts("nullptr_t comparison successful.");
}
return EXIT_SUCCESS;
}
```
The crash output:
```
during GIMPLE pass: profile_estimate
<source>: In function 'process_array':
<source>:34:1: internal compiler error: in fold_convert_loc, at
fold-const.cc:2670
34 | }
| ^
0x2558885 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
???:0
0x254dea6 internal_error(char const*, ...)
???:0
0xa0607a fancy_abort(char const*, int, char const*)
???:0
0x136a082 number_of_iterations_exit(loop*, edge_def*, tree_niter_desc*, bool,
bool, basic_block_def**)
???:0
0x109dfb1 tree_estimate_probability(bool)
???:0
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.
Compiler returned: 1
```
