ceph/src/common/crc32c_intel_fast.c

   1 #include "acconfig.h"
   2 #include "include/int_types.h"
   3 #include "common/crc32c_intel_baseline.h"
   4
   5 extern unsigned int crc32_iscsi_00(unsigned char const *buffer, int len, unsigned int crc);
   6 extern unsigned int crc32_iscsi_zero_00(unsigned char const *buffer, int len, unsigned int crc);
   7
   8 #ifdef HAVE_GOOD_YASM_ELF64
   9
  10 uint32_t ceph_crc32c_intel_fast(uint32_t crc, unsigned char const *buffer, unsigned len)
  11 {
  12         uint32_t v;
  13         unsigned left;
  14
  15
  16         if (!buffer)
  17                 return crc32_iscsi_zero_00(buffer, len, crc);
  18
  19         /*
  20          * the crc32_iscsi_00 method reads past buffer+len (because it
  21          * reads full words) which makes valgrind unhappy.  don't do
  22          * that.
  23          */
  24         if (len < 16)
  25                 return ceph_crc32c_intel_baseline(crc, buffer, len);
  26         left = ((unsigned long)buffer + len) & 7;
  27         len -= left;
  28         v = crc32_iscsi_00(buffer, len, crc);
  29         if (left)
  30                 v = ceph_crc32c_intel_baseline(v, buffer + len, left);
  31         return v;
  32 }
  33
  34 int ceph_crc32c_intel_fast_exists(void)
  35 {
  36         return 1;
  37 }
  38
  39 #else
  40
  41 int ceph_crc32c_intel_fast_exists(void)
  42 {
  43         return 0;
  44 }
  45
  46 uint32_t ceph_crc32c_intel_fast(uint32_t crc, unsigned char const *buffer, unsigned len)
  47 {
  48         return 0;
  49 }
  50
  51 #endif