https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81088
Bug ID: 81088
Summary: UBSAN: false positive as a result of reassosiation
Product: gcc
Version: 8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: babokin at gmail dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
gcc rev249171.
> cat f.cpp
short s = 2;
short y = 1;
int i;
int main() {
i = -(s + int(~unsigned(0 / y))) + 0x7fffffff;
return 0;
}
> g++ -fsanitize=undefined -O0 f.cpp -o out
> ./out
f.cpp:5:36: runtime error: signed integer overflow: -2 + -2147483648 cannot be
represented in type 'int'
