test1.c

/* wrong output with pathcc -O1
 * the return value is not truncated to 32 bits */

#include <stdio.h>

unsigned long foo(unsigned long a, unsigned b)
{
    b -= a;
    return b;
}

int main(void)
{
    printf("%016lx\n", foo(2, 1));
    return 0;
}

test2.c

/* wrong output with pathcc -O3
 * the loop is incorrectly vectorised with pslld,
 * which is not an element-wise shift as the compiler
 * appears to believe */

#include <stdio.h>

#define N 8

void print(unsigned *v)
{
    int i;
    for (i = 0; i < N; i++)
        printf("v[%2d] = %08x\n", i, v[i]);
}

int main(void)
{
    unsigned v[N];
    unsigned i;

    for (i = 0; i < N; i++)
        v[i] = 1 << i;

    print(v);
    return 0;
}