https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106070
Bug ID: 106070
Summary: Wrong code with -O1
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: vsevolod.livinskiy at gmail dot com
Target Milestone: ---
GCC produces incorrect code with -O1.
I was not able to merge the test into a single file.
Reproducer:
// func.cpp
extern unsigned var_2;
extern int var_4;
extern signed char var_10;
extern unsigned long long arr_252;
void test() {
for (unsigned a = 0; a < (unsigned char)var_10; a += 2)
arr_252 = var_2 != var_4 ? var_4 : (long)var_2;
}
//driver.cpp
#include <stdio.h>
unsigned int var_2 = 1;
int var_4 = -1;
signed char var_10 = (signed char)(-127 - 1);
unsigned long long int arr_252;
void test();
int main() {
test();
printf("%llx\n", arr_252);
if (arr_252 != 0xffffffffffffffff)
__builtin_abort();
}
Error:
>$ g++ -O0 func.cpp driver.cpp && ./a.out
ffffffffffffffff
>$ g++ -O1 func.cpp driver.cpp && ./a.out
ffffffff
Aborted (core dumped)
gcc version 13.0.0 20220623 (31ce821a790caec8a2849dd67a9847e78a33d14c)
