Hi,
I found a compiler bug in pgcpp 13.2-0 64-bit target on x86-64 Windows. The bug is caused due to erroneous optimization. Here is a test program that reproduces the bug:
/// Usage:
/// $ pgcpp bug.cpp -o bug
/// $ ./bug 10
/// $ pgcpp -fast bug.cpp -o bug
/// $ ./bug 10
#include <iostream>
#include <limits>
#include <cstdlib>
#include <stdint.h>
int main(int, char* argv[])
{
if (argv[1]) {
uint64_t MAX_UINT32 = std::numeric_limits<uint32_t>::max();
uint64_t MAX_UINT64 = std::numeric_limits<uint64_t>::max();
int factor = atoi(argv[1]);
uint64_t result = MAX_UINT64 - MAX_UINT32 * factor;
std::cout << result << std::endl;
}
}
The non optimized version prints the correct result ‘18446744030759878665’ while the optimized version (-fast or -O2) prints ‘9’ which is an error.