1 files changed, 38 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/lshrti3.c b/compiler-rt/lib/builtins/lshrti3.c
new file mode 100644
index 000000000000..d00a22095993
--- /dev/null
+++ b/compiler-rt/lib/builtins/lshrti3.c
@@ -0,0 +1,38 @@
+//===-- lshrti3.c - Implement __lshrti3 -----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __lshrti3 for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+
+#ifdef CRT_HAS_128BIT
+
+// Returns: logical a >> b
+
+// Precondition:  0 <= b < bits_in_tword
+
+COMPILER_RT_ABI ti_int __lshrti3(ti_int a, si_int b) {
+  const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT);
+  utwords input;
+  utwords result;
+  input.all = a;
+  if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ {
+    result.s.high = 0;
+    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 // CRT_HAS_128BIT