#668 Random number generator infinite loop?


The Complex Random Number generator in z-rand.c near lines 170 seems to have an infinite loop issue.

Forcing the game to use the LCRNG by commenting out this code allows it to work.

The symptoms manifest as a failure in the midst of character generation. Before the autoroller screen plots, the game just goes away forever.

astuckey@gt5228:/usr/local/src/zangband-2.7.4$ gdb ./zangband
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This GDB was configured as "x86_64-linux-gnu"...
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb) run
Starting program: /usr/local/src/zangband-2.7.4/zangband

Program received signal SIGINT, Interrupt.
Rand_div (m=3) at src/z-rand.c:177
177 if (r < m) break;
(gdb) where
#0 Rand_div (m=3) at src/z-rand.c:177
#1 0x000000000045d071 in get_stats () at src/birth.c:210
#2 0x000000000045df64 in player_birth () at src/birth.c:1432
#3 0x000000000047c255 in play_game (new_game=1 '\001') at src/dungeon.c:3267
#4 0x00000000004b85e3 in main (argc=<value optimized out>,
argv=0x7fff18166808) at src/main.c:733
(gdb) Script done, file is typescript


  • Logged In: NO

    I'm guessing that you are running on a 64 bit system? I have the same issue, but I don't think it is an infinite loop. If you try a random sex, it will eventually choose one, but it takes ~30 secs. I think the RNG doesn't converge in a 64 bit background.

  • Logged In: NO

    The problem is that zangband does not detect 64 bit GCC

    Insert the following code in src/h-type.h at line 106 to fix

    /* detect 64 bit GCC */
    #ifdef _LP64
    #define L64 1
    #define USE_64B 1