gcc/testsuite/gcc.dg/20050922-1.c

   1 /* This revealed a bug when rotates are expanded into
   2    two shifts.  */
   3
   4 /* { dg-do run } */
   5 /* { dg-options "-O1 -std=c99" } */
   6
   7 extern void abort (void);
   8
   9 #if __INT_MAX__ == 2147483647
  10 typedef unsigned int uint32_t;
  11 #elif __LONG_MAX__ == 2147483647
  12 typedef unsigned long uint32_t;
  13 #else
  14 #error unable to find 32-bit integer type
  15 #endif
  16
  17 uint32_t
  18 f (uint32_t *S, int j)
  19 {
  20   uint32_t A, B, k, L[2] = {1234, 5678};
  21   int i, m;
  22
  23   A = B = 0;
  24   for (i = 0; i < j; i++)
  25     {
  26       k = (S[i] + A + B) & 0xffffffffL;
  27       A = S[i] =
  28       ((k << (3 & 0x1f)) | ((k & 0xffffffff) >> (32 - (3 & 0x1f))));
  29
  30       m = (int) (A + B);
  31       k = (L[i] + A + B) & 0xffffffffL;
  32       B = L[i] =
  33         ((k << (m & 0x1f)) | ((k & 0xffffffff) >> (32 - (m & 0x1f))));
  34     }
  35   return L[0] + L[1];
  36 }
  37
  38 int
  39 main ()
  40 {
  41   uint32_t S[2] = {0xffff, 0xffffff};
  42
  43   if (f (S,2)!= 1392607300)
  44     abort();
  45
  46   return 0;
  47 }