initial code repo

[stor4nfv.git] / src / ceph / src / common / crc32c_intel_fast.c

diff --git a/src/ceph/src/common/crc32c_intel_fast.c b/src/ceph/src/common/crc32c_intel_fast.c
new file mode 100644 (file)
index 0000000..adaf3d7
--- /dev/null
+++ b/src/ceph/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, int len, unsigned int crc);
+extern unsigned int crc32_iscsi_zero_00(unsigned char const *buffer, int len, unsigned int crc);
+
+#ifdef HAVE_GOOD_YASM_ELF64
+
+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