Initial import

third_party/compiler_rt/muldi3.c

@@ -0,0 +1,61 @@
+/* clang-format off */
+/* ===-- muldi3.c - Implement __muldi3 -------------------------------------===
+ *
+ *                     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 __muldi3 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+STATIC_YOINK("huge_compiler_rt_license");
+
+#include "third_party/compiler_rt/int_lib.h"
+
+/* Returns: a * b */
+
+static
+di_int
+__muldsi3(su_int a, su_int b)
+{
+    dwords r;
+    const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2;
+    const su_int lower_mask = (su_int)~0 >> bits_in_word_2;
+    r.s.low = (a & lower_mask) * (b & lower_mask);
+    su_int t = r.s.low >> bits_in_word_2;
+    r.s.low &= lower_mask;
+    t += (a >> bits_in_word_2) * (b & lower_mask);
+    r.s.low += (t & lower_mask) << bits_in_word_2;
+    r.s.high = t >> bits_in_word_2;
+    t = r.s.low >> bits_in_word_2;
+    r.s.low &= lower_mask;
+    t += (b >> bits_in_word_2) * (a & lower_mask);
+    r.s.low += (t & lower_mask) << bits_in_word_2;
+    r.s.high += t >> bits_in_word_2;
+    r.s.high += (a >> bits_in_word_2) * (b >> bits_in_word_2);
+    return r.all;
+}
+
+/* Returns: a * b */
+
+COMPILER_RT_ABI di_int
+__muldi3(di_int a, di_int b)
+{
+    dwords x;
+    x.all = a;
+    dwords y;
+    y.all = b;
+    dwords r;
+    r.all = __muldsi3(x.s.low, y.s.low);
+    r.s.high += x.s.high * y.s.low + x.s.low * y.s.high;
+    return r.all;
+}
+
+#if defined(__ARM_EABI__)
+AEABI_RTABI di_int __aeabi_lmul(di_int a, di_int b) COMPILER_RT_ALIAS(__muldi3);
+#endif