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

1 files changed, 43 insertions, 0 deletions

diff --git a/lib/builtins/lshrdi3.c b/lib/builtins/lshrdi3.c
new file mode 100644
index 000000000..6b1ea923b
--- /dev/null
+++ b/lib/builtins/lshrdi3.c
@@ -0,0 +1,43 @@
+/* ===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------===
+ *
+ *                     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 __lshrdi3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: logical a >> b */
+
+/* Precondition:  0 <= b < bits_in_dword */
+
+ARM_EABI_FNALIAS(llsr, lshrdi3)
+
+COMPILER_RT_ABI di_int
+__lshrdi3(di_int a, si_int b)
+{
+    const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
+    udwords input;
+    udwords result;
+    input.all = a;
+    if (b & bits_in_word)  /* bits_in_word <= b < bits_in_dword */
+    {
+        result.s.high = 0;
+        result.s.low = input.s.high >> (b - bits_in_word);
+    }
+    else  /* 0 <= b < bits_in_word */
+    {
+        if (b == 0)
+            return a;
+        result.s.high  = input.s.high >> b;
+        result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b);
+    }
+    return result.all;
+}