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1//===-- muldi3.c - Implement __muldi3 -------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements __muldi3 for the compiler_rt library.10//11//===----------------------------------------------------------------------===//12 13#include "int_lib.h"14 15// Returns: a * b16 17static di_int __muldsi3(su_int a, su_int b) {18 dwords r;19 const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2;20 const su_int lower_mask = (su_int)~0 >> bits_in_word_2;21 r.s.low = (a & lower_mask) * (b & lower_mask);22 su_int t = r.s.low >> bits_in_word_2;23 r.s.low &= lower_mask;24 t += (a >> bits_in_word_2) * (b & lower_mask);25 r.s.low += (t & lower_mask) << bits_in_word_2;26 r.s.high = t >> bits_in_word_2;27 t = r.s.low >> bits_in_word_2;28 r.s.low &= lower_mask;29 t += (b >> bits_in_word_2) * (a & lower_mask);30 r.s.low += (t & lower_mask) << bits_in_word_2;31 r.s.high += t >> bits_in_word_2;32 r.s.high += (a >> bits_in_word_2) * (b >> bits_in_word_2);33 return r.all;34}35 36// Returns: a * b37 38COMPILER_RT_ABI di_int __muldi3(di_int a, di_int b) {39 dwords x;40 x.all = a;41 dwords y;42 y.all = b;43 dwords r;44 r.all = __muldsi3(x.s.low, y.s.low);45 r.s.high += x.s.high * y.s.low + x.s.low * y.s.high;46 return r.all;47}48 49#if defined(__ARM_EABI__)50COMPILER_RT_ALIAS(__muldi3, __aeabi_lmul)51#endif52