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

   1 /* { dg-do compile { target arm*-*-* alpha*-*-* i?86-*-* powerpc*-*-* rs6000-*-* x86_64-*-* s390*-*-* } } */
   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 /* This byte swap implementation is used by the Linux kernel and the
  14    GNU C library.  */
  15
  16 uint32_t
  17 swap32_a (uint32_t in)
  18 {
  19   return __const_swab32 (in);
  20 }
  21
  22 /* The OpenSSH byte swap implementation.  */
  23 uint32_t
  24 swap32_b (uint32_t in)
  25 {
  26   uint32_t a;
  27
  28   a = (in << 16) | (in >> 16);
  29   a = ((a & 0x00ff00ff) << 8) | ((a & 0xff00ff00) >> 8);
  30
  31   return a;
  32 }
  33
  34 /* This variant is currently used by libgcc.  The difference is that
  35    the bswap source and destination have a signed integer type which
  36    requires a slightly higher search depth in order to dive through
  37    the cast as well.  */
  38
  39 typedef int SItype __attribute__ ((mode (SI)));
  40
  41 SItype
  42 swap32_c (SItype u)
  43 {
  44   return ((((u) & 0xff000000) >> 24)
  45           | (((u) & 0x00ff0000) >>  8)
  46           | (((u) & 0x0000ff00) <<  8)
  47           | (((u) & 0x000000ff) << 24));
  48 }
  49
  50 /* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 3 "bswap" } } */
  51 /* { dg-final { cleanup-tree-dump "bswap" } } */