Initial import

third_party/compiler_rt/ashlti3.c

@@ -0,0 +1,48 @@
+/* clang-format off */
+/* ===-- ashlti3.c - Implement __ashlti3 -----------------------------------===
+ *
+ *                     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 __ashlti3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+STATIC_YOINK("huge_compiler_rt_license");
+
+#include "third_party/compiler_rt/int_lib.h"
+
+#ifdef CRT_HAS_128BIT
+
+/* Returns: a << b */
+
+/* Precondition:  0 <= b < bits_in_tword */
+
+COMPILER_RT_ABI ti_int
+__ashlti3(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.low = 0;
+        result.s.high = input.s.low << (b - bits_in_dword);
+    }
+    else  /* 0 <= b < bits_in_dword */
+    {
+        if (b == 0)
+            return a;
+        result.s.low  = input.s.low << b;
+        result.s.high = (input.s.high << b) | (input.s.low >> (bits_in_dword - b));
+    }
+    return result.all;
+}
+
+#endif /* CRT_HAS_128BIT */