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diff --git a/lib/ashldi3.c b/lib/ashldi3.c
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+/* ====-- ashldi3.c - Implement __ashldi3 -----------------------------------===
+ *
+ * The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __ashldi3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#include "int_lib.h"
+
+/* Returns: a << b */
+
+/* Precondition: 0 <= b < bits_in_dword */
+
+di_int
+__ashldi3(di_int a, si_int b)
+{
+ const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT);
+ dwords input;
+ dwords result;
+ input.all = a;
+ if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */
+ {
+ result.s.low = 0;
+ result.s.high = input.s.low << (b - bits_in_word);
+ }
+ else /* 0 <= b < bits_in_word */
+ {
+ if (b == 0)
+ return a;
+ result.s.low = input.s.low << b;
+ result.s.high = (input.s.high << b) | (input.s.low >> (bits_in_word - b));
+ }
+ return result.all;
+}