summaryrefslogtreecommitdiff
path: root/lib/builtins/clzti2.c
diff options
context:
space:
mode:
authorAlexey Samsonov <samsonov@google.com>2014-02-14 09:20:33 +0000
committerAlexey Samsonov <samsonov@google.com>2014-02-14 09:20:33 +0000
commit53aa4fda49f94920139300227786ac47c393f1ce (patch)
tree6d022d04ee279fe1afd89668f346e28a9e3e1559 /lib/builtins/clzti2.c
parent6d999e478fecb10dc43f20b85385d25cc239db0a (diff)
Move original compiler-rt functions (libgcc replacement) to lib/builtins directory
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@201393 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/builtins/clzti2.c')
-rw-r--r--lib/builtins/clzti2.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/lib/builtins/clzti2.c b/lib/builtins/clzti2.c
new file mode 100644
index 000000000..355c20e42
--- /dev/null
+++ b/lib/builtins/clzti2.c
@@ -0,0 +1,33 @@
+/* ===-- clzti2.c - Implement __clzti2 -------------------------------------===
+ *
+ * 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 __clzti2 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+#if __x86_64
+
+/* Returns: the number of leading 0-bits */
+
+/* Precondition: a != 0 */
+
+si_int
+__clzti2(ti_int a)
+{
+ twords x;
+ x.all = a;
+ const di_int f = -(x.s.high == 0);
+ return __builtin_clzll((x.s.high & ~f) | (x.s.low & f)) +
+ ((si_int)f & ((si_int)(sizeof(di_int) * CHAR_BIT)));
+}
+
+#endif /* __x86_64 */