when the binary file is execve'ed with dtruss, R9 register is set to 0x18 or R11 != 0xffffffff00000000

dtruss.c

#include <stdio.h>

int main() {
    unsigned long val;
    __asm__ (
            "movq %%r9, %0"
            :"=m"(val)
            );

#ifdef DEBUG
    printf("%%r9 = 0x%lx\n", val);
#endif
    if (val == 0x18)
        exit(1);

    while(1){ }
    return (0);
}

dtruss2.c

#include <stdio.h>

int main() {
    unsigned long val;
    __asm__ (
            "movq %%r11, %0"
            :"=m"(val)
            );

#ifdef DEBUG
    printf("%%r11 = 0x%lx\n", ~val);
#endif
    if (~(val) != 0xffffffff)
        exit(1);

    while(1){ }
    return (0);
}