1 files changed, 69 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/roken/clz.c b/third_party/heimdal/lib/roken/clz.c
new file mode 100644
index 00000000000..1a36234f16a
--- /dev/null
+++ b/third_party/heimdal/lib/roken/clz.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip.
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <config.h>
+#include <assert.h>
+
+#include "roken.h"
+
+#if defined(_MSC_VER)
+#include <intrin.h>
+#if defined(_WIN64)
+#pragma intrinsic(_BitScanReverse64)
+#else
+#pragma intrinsic(_BitScanReverse)
+#endif
+#endif
+
+ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
+rk_clzll(uint64_t x)
+{
+#if defined(_MSC_VER)
+    unsigned long r = 0;
+#elif !(defined(__GNUC__) && __GNUC__ >= 4)
+    int r = 0;
+#endif
+
+    assert(x != 0);
+
+#if defined(_MSC_VER)
+# if defined(_WIN64)
+    _BitScanReverse64(&r, x);
+# else
+    if (_BitScanReverse(&r, (uint32_t)(x >> 32)))
+        return 63 - (r + 32);
+    _BitScanReverse(&r, (uint32_t)(x & 0xFFFFFFFF));
+# endif
+
+    return 63 - r;
+#elif (defined(__GNUC__) && __GNUC__ >= 4)
+    return __builtin_clzll(x);
+#else
+    while (!(x & ((uint64_t)1 << 63))) {
+        x <<= 1;
+        ++r;
+    }
+
+    return r;
+#endif /* _MSC_VER || __GNUC__ */
+}