crypto/external/bsd/openssl/dist/bugs/sgiccbug.c

   1 /* NOCW */
   2 /* sgibug.c */
   3 /* bug found by Eric Young (eay@mincom.oz.au) May 95 */
   4
   5 #include <stdio.h>
   6
   7 /*
   8  * This compiler bug it present on IRIX 5.3, 5.1 and 4.0.5 (these are the
   9  * only versions of IRIX I have access to. defining FIXBUG removes the bug.
  10  * (bug is still present in IRIX 6.3 according to Gage
  11  * <agage@forgetmenot.Mines.EDU>
  12  */
  13
  14 /*-
  15  * Compare the output from
  16  * cc sgiccbug.c; ./a.out
  17  * and
  18  * cc -O sgiccbug.c; ./a.out
  19  */
  20
  21 static unsigned long a[4] =
  22     { 0x01234567, 0x89ABCDEF, 0xFEDCBA98, 0x76543210 };
  23 static unsigned long b[4] =
  24     { 0x89ABCDEF, 0xFEDCBA98, 0x76543210, 0x01234567 };
  25 static unsigned long c[4] =
  26     { 0x77777778, 0x8ACF1357, 0x88888888, 0x7530ECA9 };
  27
  28 main()
  29 {
  30     unsigned long r[4];
  31     sub(r, a, b);
  32     fprintf(stderr, "input a= %08X %08X %08X %08X\n", a[3], a[2], a[1], a[0]);
  33     fprintf(stderr, "input b= %08X %08X %08X %08X\n", b[3], b[2], b[1], b[0]);
  34     fprintf(stderr, "output = %08X %08X %08X %08X\n", r[3], r[2], r[1], r[0]);
  35     fprintf(stderr, "correct= %08X %08X %08X %08X\n", c[3], c[2], c[1], c[0]);
  36 }
  37
  38 int sub(r, a, b)
  39 unsigned long *r, *a, *b;
  40 {
  41     register unsigned long t1, t2, *ap, *bp, *rp;
  42     int i, carry;
  43 #ifdef FIXBUG
  44     unsigned long dummy;
  45 #endif
  46
  47     ap = a;
  48     bp = b;
  49     rp = r;
  50     carry = 0;
  51     for (i = 0; i < 4; i++) {
  52         t1 = *(ap++);
  53         t2 = *(bp++);
  54         t1 = (t1 - t2);
  55 #ifdef FIXBUG
  56         dummy = t1;
  57 #endif
  58         *(rp++) = t1 & 0xffffffff;
  59     }
  60 }