#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "crc32c.h"
/*
* Based on a posting to lkml by Austin Zhang <austin.zhang@intel.com>
* Volume 2A: Instruction Set Reference, A-M
*/
+int crc32c_intel_available = 0;
+
+#ifdef ARCH_HAVE_SSE4_2
+
#if BITS_PER_LONG == 64
#define REX_PRE "0x48, "
#define SCALE_F 8
#define SCALE_F 4
#endif
-uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data,
- unsigned long length)
+static int crc32c_probed;
+
+static uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data,
+ unsigned long length)
{
while (length--) {
__asm__ __volatile__(
return crc;
}
+
+static void do_cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx,
+ unsigned int *edx)
+{
+ int id = *eax;
+
+ asm("movl %4, %%eax;"
+ "cpuid;"
+ "movl %%eax, %0;"
+ "movl %%ebx, %1;"
+ "movl %%ecx, %2;"
+ "movl %%edx, %3;"
+ : "=r" (*eax), "=r" (*ebx), "=r" (*ecx), "=r" (*edx)
+ : "r" (id)
+ : "eax", "ebx", "ecx", "edx");
+}
+
+void crc32c_intel_probe(void)
+{
+ if (!crc32c_probed) {
+ unsigned int eax, ebx, ecx, edx;
+
+ eax = 1;
+
+ do_cpuid(&eax, &ebx, &ecx, &edx);
+ crc32c_intel_available = (ecx & (1 << 20)) != 0;
+ crc32c_probed = 1;
+ }
+}
+
+#endif /* ARCH_HAVE_SSE */