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

   1 /* { dg-do compile } */
   2 /* { dg-require-effective-target bswap } */
   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 /* This variant comes from gcc.target/sh/pr53568-1.c.  It requires to track
  53    which bytes have an unpredictable value (eg. due to sign extension) to
  54    make sure that the final expression have only well defined byte values.  */
  55
  56 SItype
  57 swap32_d (SItype in)
  58 {
  59   /* 1x swap.w
  60      2x swap.b  */
  61   return (((in >> 0) & 0xFF) << 24)
  62          | (((in >> 8) & 0xFF) << 16)
  63          | (((in >> 16) & 0xFF) << 8)
  64          | (((in >> 24) & 0xFF) << 0);
  65 }
  66
  67 /* This variant is adapted from swap32_d above.  It detects missing cast of
  68    MARKER_BYTE_UNKNOWN to uint64_t for the CASE_CONVERT case for host
  69    architecture where a left shift with too big an operand mask its high
  70    bits.  */
  71
  72 SItype
  73 swap32_e (SItype in)
  74 {
  75   return (((in >> 0) & 0xFF) << 24)
  76          | (((in >> 8) & 0xFF) << 16)
  77          | (((((int64_t) in) & 0xFF0000FF0000) >> 16) << 8)
  78          | (((in >> 24) & 0xFF) << 0);
  79 }
  80
  81 /* This variant comes from PR63259.  It compiles to a gimple sequence that ends
  82    with a rotation instead of a bitwise OR.  */
  83
  84 unsigned
  85 swap32_f (unsigned in)
  86 {
  87   in = ((in & 0xff00ff00) >>  8) | ((in & 0x00ff00ff) <<  8);
  88   in = ((in & 0xffff0000) >> 16) | ((in & 0x0000ffff) << 16);
  89   return in;
  90 }
  91
  92 /* { dg-final { scan-tree-dump-times "32 bit bswap implementation found at" 6 "bswap" } } */