1 /* ===-- muldi3.c - Implement __muldi3 -------------------------------------===
3 * The LLVM Compiler Infrastructure
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
8 * ===----------------------------------------------------------------------===
10 * This file implements __muldi3 for the compiler_rt library.
12 * ===----------------------------------------------------------------------===
21 __muldsi3(su_int a, su_int b)
24 const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2;
25 const su_int lower_mask = (su_int)~0 >> bits_in_word_2;
26 r.s.low = (a & lower_mask) * (b & lower_mask);
27 su_int t = r.s.low >> bits_in_word_2;
28 r.s.low &= lower_mask;
29 t += (a >> bits_in_word_2) * (b & lower_mask);
30 r.s.low += (t & lower_mask) << bits_in_word_2;
31 r.s.high = t >> bits_in_word_2;
32 t = r.s.low >> bits_in_word_2;
33 r.s.low &= lower_mask;
34 t += (b >> bits_in_word_2) * (a & lower_mask);
35 r.s.low += (t & lower_mask) << bits_in_word_2;
36 r.s.high += t >> bits_in_word_2;
37 r.s.high += (a >> bits_in_word_2) * (b >> bits_in_word_2);
43 ARM_EABI_FNALIAS(lmul, muldi3)
45 COMPILER_RT_ABI di_int
46 __muldi3(di_int a, di_int b)
53 r.all = __muldsi3(x.s.low, y.s.low);
54 r.s.high += x.s.high * y.s.low + x.s.low * y.s.high;