Initial import

third_party/compiler_rt/ffsdi2.c

@@ -0,0 +1,36 @@
+/* clang-format off */
+/* ===-- ffsdi2.c - Implement __ffsdi2 -------------------------------------===
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is dual licensed under the MIT and the University of Illinois Open
+ * Source Licenses. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __ffsdi2 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+STATIC_YOINK("huge_compiler_rt_license");
+
+#include "third_party/compiler_rt/int_lib.h"
+
+/* Returns: the index of the least significant 1-bit in a, or
+ * the value zero if a is zero. The least significant bit is index one.
+ */
+
+COMPILER_RT_ABI si_int
+__ffsdi2(di_int a)
+{
+    dwords x;
+    x.all = a;
+    if (x.s.low == 0)
+    {
+        if (x.s.high == 0)
+            return 0;
+        return __builtin_ctz(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
+    }
+    return __builtin_ctz(x.s.low) + 1;
+}