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

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target bswap32 } */
   3 /* { dg-require-effective-target stdint_types } */
   4 /* { dg-options "-O2 -fdump-tree-bswap" } */
   5 /* { dg-additional-options "-march=z900" { target s390-*-* } } */
   6
   7 #include <stdint.h>
   8
   9 #define __const_swab32(x) ((uint32_t)(                                \
  10         (((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) |            \
  11         (((uint32_t)(x) & (uint32_t)0x0000ff00UL) <<  8) |            \
  12         (((uint32_t)(x) & (uint32_t)0x00ff0000UL) >>  8) |            \
  13         (((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
  14
  15 /* This byte swap implementation is used by the Linux kernel and the
  16    GNU C library.  */
  17
  18 uint32_t
  19 swap32_a (uint32_t in)
  20 {
  21   return __const_swab32 (in);
  22 }
  23
  24 /* The OpenSSH byte swap implementation.  */
  25 uint32_t
  26 swap32_b (uint32_t in)
  27 {
  28   uint32_t a;
  29
  30   a = (in << 16) | (in >> 16);
  31   a = ((a & 0x00ff00ff) << 8) | ((a & 0xff00ff00) >> 8);
  32
  33   return a;
  34 }
  35
  36 /* This variant is currently used by libgcc.  The difference is that
  37    the bswap source and destination have a signed integer type which
  38    requires a slightly higher search depth in order to dive through
  39    the cast as well.  */
  40
  41 typedef int SItype __attribute__ ((mode (SI)));
  42
  43 SItype
  44 swap32_c (SItype u)
  45 {
  46   return ((((u) & 0xff000000) >> 24)
  47           | (((u) & 0x00ff0000) >>  8)
  48           | (((u) & 0x0000ff00) <<  8)
  49           | (((u) & 0x000000ff) << 24));
  50 }
  51
  52 /* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 3 "bswap" } } */
  53 /* { dg-final { cleanup-tree-dump "bswap" } } */