usr/othersrc/public/ghostscript-2.4.1/genarch.c

/* genarch.c */
/* Generate a header file (arch.h) with parameters */
/* reflecting the machine architecture and compiler characteristics. */

#include <stdio.h>

/* We should write the result on stdout, but the Turbo C 'make' */
/* can't handle output redirection (sigh). */

main(argc, argv)
    int argc;
    char *argv[];
{       char *fname = argv[1];
        long one = 1;
        long lm1 = -1;
        long lr1 = lm1 >> 1, lr2 = lm1 >> 2;
        unsigned long um1 = ~(unsigned long)0;
        int im1 = -1;
        int ir1 = im1 >> 1, ir2 = im1 >> 2;
        int ars;
        int lwidth = sizeof(long) * 8;
        float f0 = 0.0, f1 = 1.0, fm1 = -1.0;
        FILE *f = fopen(fname, "w");
        if ( f == NULL )
           {    fprintf(stderr, "genarch.c: can't open %s for writing\n", fname);
                exit(1);
           }
        fprintf(f, "/* Parameters derived from machine and compiler architecture */\n\n");
        fprintf(f, "#define arch_is_big_endian %d\n", 1 - *(char *)&one);
        fprintf(f, "#define arch_sizeof_short %d\n", sizeof(short));
        fprintf(f, "#define arch_sizeof_int %d\n", sizeof(int));
        fprintf(f, "#define arch_sizeof_long %d\n", sizeof(long));
        fprintf(f, "#define arch_floats_are_IEEE %d\n",
                (*(long *)&f0 == 0 && *(long *)&f1 == 0x3f800000L &&
                 *(long *)&fm1 == 0xbf800000L ? 1 : 0));
        /* There are three cases for arithmetic right shift: */
        /* always correct, correct except for right-shifting a long by 1 */
        /* (a bug in some versions of the Turbo C compiler), and */
        /* never correct. */
        ars = (lr2 != -1 || ir1 != -1 || ir2 != -1 ? 0 :
                lr1 != -1 ? 1 :         /* Turbo C problem */
                2);
        fprintf(f, "#define arch_arith_rshift %d\n", ars);
        /* Some machines can't handle a variable shift by */
        /* the full width of a long. */
        fprintf(f, "#define arch_can_shift_full_long %d\n",
                um1 >> lwidth == 0);
        fclose(f);
        return 0;
}