| //===-- muldi3.c - Implement __muldi3 -------------------------------------===// |
| // |
| // 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 __muldi3 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "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__) |
| COMPILER_RT_ALIAS(__muldi3, __aeabi_lmul) |
| #endif |