Using CRC32 from CPU

[Pjot]

All,

Currently I am working on some code for which I need a CRC32 check. It appears that CPU's with the SSE4.2 extension have the CRC32 function built-in.

How can we make use of such a wonderful free gift from our CPU? We can use some GCC facilities.

PRAGMA OPTIONS -msse4.2

IF __builtin_cpu_supports("sse4.2") THEN
   COLOR FG TO GREEN
   PRINT "Cool, this CPU supports CRC32!"
   COLOR RESET
ELSE
   COLOR FG TO RED
   PRINT "Too bad, this CPU does not support CRC32!"
   COLOR RESET
   END
ENDIF

FUNC calculate_crc32_cpu(uint8_t *data, size_t len) TYPE uint32_t

   LOCAL crc = 0 TYPE uint32_t
   LOCAL i

   FOR i = 0 TO len-1
       crc = __builtin_ia32_crc32qi(crc, data[i])
   NEXT
   RETURN crc
ENDFUNC

str$ = "This is some data"

PRINT "CRC32 is: ", calculate_crc32_cpu(str$, LEN(str$))


BR
Peter