gcc/testsuite/gcc.c-torture/execute/bswap-2.c

   1 /* { dg-require-effective-target int32plus } */
   2
   3 #ifdef __UINT32_TYPE__
   4 typedef __UINT32_TYPE__ uint32_t;
   5 #else
   6 typedef __UINT32_TYPE__ unsigned;
   7 #endif
   8
   9 struct bitfield {
  10   unsigned char f0:7;
  11   unsigned char   :1;
  12   unsigned char f1:7;
  13   unsigned char   :1;
  14   unsigned char f2:7;
  15   unsigned char   :1;
  16   unsigned char f3:7;
  17 };
  18
  19 struct ok {
  20   unsigned char f0;
  21   unsigned char f1;
  22   unsigned char f2;
  23   unsigned char f3;
  24 };
  25
  26 union bf_or_uint32 {
  27   struct ok inval;
  28   struct bitfield bfval;
  29 };
  30
  31 __attribute__ ((noinline, noclone)) uint32_t
  32 partial_read_le32 (union bf_or_uint32 in)
  33 {
  34   return in.bfval.f0 | (in.bfval.f1 << 8)
  35          | (in.bfval.f2 << 16) | (in.bfval.f3 << 24);
  36 }
  37
  38 __attribute__ ((noinline, noclone)) uint32_t
  39 partial_read_be32 (union bf_or_uint32 in)
  40 {
  41   return in.bfval.f3 | (in.bfval.f2 << 8)
  42          | (in.bfval.f1 << 16) | (in.bfval.f0 << 24);
  43 }
  44
  45 __attribute__ ((noinline, noclone)) uint32_t
  46 fake_read_le32 (char *x, char *y)
  47 {
  48   unsigned char c0, c1, c2, c3;
  49
  50   c0 = x[0];
  51   c1 = x[1];
  52   *y = 1;
  53   c2 = x[2];
  54   c3 = x[3];
  55   return c0 | c1 << 8 | c2 << 16 | c3 << 24;
  56 }
  57
  58 __attribute__ ((noinline, noclone)) uint32_t
  59 fake_read_be32 (char *x, char *y)
  60 {
  61   unsigned char c0, c1, c2, c3;
  62
  63   c0 = x[0];
  64   c1 = x[1];
  65   *y = 1;
  66   c2 = x[2];
  67   c3 = x[3];
  68   return c3 | c2 << 8 | c1 << 16 | c0 << 24;
  69 }
  70
  71 __attribute__ ((noinline, noclone)) uint32_t
  72 incorrect_read_le32 (char *x, char *y)
  73 {
  74   unsigned char c0, c1, c2, c3;
  75
  76   c0 = x[0];
  77   c1 = x[1];
  78   c2 = x[2];
  79   c3 = x[3];
  80   *y = 1;
  81   return c0 | c1 << 8 | c2 << 16 | c3 << 24;
  82 }
  83
  84 __attribute__ ((noinline, noclone)) uint32_t
  85 incorrect_read_be32 (char *x, char *y)
  86 {
  87   unsigned char c0, c1, c2, c3;
  88
  89   c0 = x[0];
  90   c1 = x[1];
  91   c2 = x[2];
  92   c3 = x[3];
  93   *y = 1;
  94   return c3 | c2 << 8 | c1 << 16 | c0 << 24;
  95 }
  96
  97 int
  98 main ()
  99 {
 100   union bf_or_uint32 bfin;
 101   uint32_t out;
 102   char cin[] = { 0x83, 0x85, 0x87, 0x89 };
 103
 104   if (sizeof (uint32_t) * __CHAR_BIT__ != 32)
 105     return 0;
 106   bfin.inval = (struct ok) { 0x83, 0x85, 0x87, 0x89 };
 107   out = partial_read_le32 (bfin);
 108   /* Test what bswap would do if its check are not strict enough instead of
 109      what is the expected result as there is too many possible results with
 110      bitfields.  */
 111   if (out == 0x89878583)
 112     __builtin_abort ();
 113   bfin.inval = (struct ok) { 0x83, 0x85, 0x87, 0x89 };
 114   out = partial_read_be32 (bfin);
 115   /* Test what bswap would do if its check are not strict enough instead of
 116      what is the expected result as there is too many possible results with
 117      bitfields.  */
 118   if (out == 0x83858789)
 119     __builtin_abort ();
 120   out = fake_read_le32 (cin, &cin[2]);
 121   if (out != 0x89018583)
 122     __builtin_abort ();
 123   cin[2] = 0x87;
 124   out = fake_read_be32 (cin, &cin[2]);
 125   if (out != 0x83850189)
 126     __builtin_abort ();
 127   cin[2] = 0x87;
 128   out = incorrect_read_le32 (cin, &cin[2]);
 129   if (out != 0x89878583)
 130     __builtin_abort ();
 131   cin[2] = 0x87;
 132   out = incorrect_read_be32 (cin, &cin[2]);
 133   if (out != 0x83858789)
 134     __builtin_abort ();
 135   return 0;
 136 }