The following (reduced) code is very badly handled by the series of GCC
#include <vector>
#include <cilk/cilk.h>
void walk(std::vector<int> v, int bnd, unsigned size) {
if (v.size() < size)
for (int i=0; i<bnd; i++) {
std::vector<int> vnew(v);
vnew.push_back(i);
cilk_spawn walk(vnew, bnd, size);
}
}
int main(int argc, char **argv) {
std::vector<int> v{};
walk(v , 5, 5);
}
Specifically:
G++ 5.3.1 crash:
red.cpp: In function ‘<built-in>’: red.cpp:20:39: internal compiler error: in lower_stmt, at gimple-low.c:397 cilk_spawn walk(vnew, bnd, size);G++ 6.3.1 create a code which works perfectly well if executed on one core but segfault sometime, signal a double free some other times if using more cores. A student who has a arch linux g++7 reported a similar result.
My question : is there something wrong with that code. Am I invoking some undefined behavior or is it simply a bug I should report ?
