gcc/testsuite/gcc.dg/optimize-bswap-1.c

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target stdint_types } */
   3 /* { dg-options "-O2 -fdump-tree-bswap" } */
   4
   5 #include <stdint.h>
   6
   7 #define __const_swab32(x) ((uint32_t)(                                \
   8         (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) |            \
   9         (((uint32_t)(x) & (uint32_t)0x0000ff00UL) <<  8) |            \
  10         (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >>  8) |            \
  11         (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
  12
  13 #define __const_swab64(x) ((uint64_t)(                                          \
  14         (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) |             \
  15         (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) |             \
  16         (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) |             \
  17         (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) <<  8) |             \
  18         (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >>  8) |             \
  19         (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) |             \
  20         (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) |             \
  21         (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56)))
  22
  23 /* This byte swap implementation is used by the Linux kernel and the
  24    GNU C library.  */
  25
  26 uint32_t
  27 swap32_a (uint32_t in)
  28 {
  29   return __const_swab32 (in);
  30 }
  31
  32 uint64_t
  33 swap64 (uint64_t in)
  34 {
  35   return __const_swab64 (in);
  36 }
  37
  38 /* The OpenSSH byte swap implementation.  */
  39 uint32_t
  40 swap32_b (uint32_t in)
  41 {
  42   uint32_t a;
  43
  44   a = (in << 16) | (in >> 16);
  45   a = ((a & 0x00ff00ff) << 8) | ((a & 0xff00ff00) >> 8);
  46
  47   return a;
  48 }
  49
  50 /* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 2 "bswap" } } */
  51 /* { dg-final { scan-tree-dump-times "64 bit bswap implementation found at" 1 "bswap" } } */
  52 /* { dg-final { cleanup-tree-dump "bswap" } } */