1 files changed, 51 insertions, 0 deletions
diff --git a/src/common/crc32c_intel_fast.c b/src/common/crc32c_intel_fast.c
new file mode 100644
index 000000000..28bd93416
--- /dev/null
+++ b/src/common/crc32c_intel_fast.c
@@ -0,0 +1,51 @@
+#include "acconfig.h"
+#include "common/crc32c_intel_baseline.h"
+
+extern unsigned int crc32_iscsi_00(unsigned char const *buffer, uint64_t len, uint64_t crc) asm("crc32_iscsi_00");
+extern unsigned int crc32_iscsi_zero_00(unsigned char const *buffer, uint64_t len, uint64_t crc) asm("crc32_iscsi_zero_00");
+
+#ifdef HAVE_NASM_X64
+
+uint32_t ceph_crc32c_intel_fast(uint32_t crc, unsigned char const *buffer, unsigned len)
+{
+	uint32_t v;
+	unsigned left;
+
+	if (!buffer)
+	{
+	  return crc32_iscsi_zero_00(buffer, len, crc);
+	}
+
+	/*
+	 * the crc32_iscsi_00 method reads past buffer+len (because it
+	 * reads full words) which makes valgrind unhappy.  don't do
+	 * that.
+	 */
+	if (len < 16)
+		return ceph_crc32c_intel_baseline(crc, buffer, len);
+	left = ((unsigned long)buffer + len) & 7;
+	len -= left;
+	v = crc32_iscsi_00(buffer, len, crc);
+	if (left)
+		v = ceph_crc32c_intel_baseline(v, buffer + len, left);
+	return v;
+}
+
+int ceph_crc32c_intel_fast_exists(void)
+{
+	return 1;
+}
+
+#else
+
+int ceph_crc32c_intel_fast_exists(void)
+{
+	return 0;
+}
+
+uint32_t ceph_crc32c_intel_fast(uint32_t crc, unsigned char const *buffer, unsigned len)
+{
+	return 0;
+}
+
+#endif