1 files changed, 46 insertions, 0 deletions
diff --git a/lib/ashrti3.c b/lib/ashrti3.c
new file mode 100644
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--- /dev/null
+++ b/lib/ashrti3.c
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+/* ===-- ashrti3.c - Implement __ashrti3 -----------------------------------===
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __ashrti3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#if __x86_64
+
+#include "int_lib.h"
+
+/* Returns: arithmetic a >> b */
+
+/* Precondition:  0 <= b < bits_in_tword */
+
+ti_int
+__ashrti3(ti_int a, si_int b)
+{
+    const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
+    twords input;
+    twords result;
+    input.all = a;
+    if (b & bits_in_dword)  /* bits_in_dword <= b < bits_in_tword */
+    {
+        /* result.s.high = input.s.high < 0 ? -1 : 0 */
+        result.s.high = input.s.high >> (bits_in_dword - 1);
+        result.s.low = input.s.high >> (b - bits_in_dword);
+    }
+    else  /* 0 <= b < bits_in_dword */
+    {
+        if (b == 0)
+            return a;
+        result.s.high  = input.s.high >> b;
+        result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b);
+    }
+    return result.all;
+}
+
+#endif /* __x86_64 */