| //===-- divsi3.c - Implement __divsi3 -------------------------------------===// |
| // |
| // 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 __divsi3 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "int_lib.h" |
| |
| // Returns: a / b |
| |
| COMPILER_RT_ABI si_int __divsi3(si_int a, si_int b) { |
| const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; |
| si_int s_a = a >> bits_in_word_m1; // s_a = a < 0 ? -1 : 0 |
| si_int s_b = b >> bits_in_word_m1; // s_b = b < 0 ? -1 : 0 |
| a = (a ^ s_a) - s_a; // negate if s_a == -1 |
| b = (b ^ s_b) - s_b; // negate if s_b == -1 |
| s_a ^= s_b; // sign of quotient |
| // |
| // On CPUs without unsigned hardware division support, |
| // this calls __udivsi3 (notice the cast to su_int). |
| // On CPUs with unsigned hardware division support, |
| // this uses the unsigned division instruction. |
| // |
| return ((su_int)a / (su_int)b ^ s_a) - s_a; // negate if s_a == -1 |
| } |
| |
| #if defined(__ARM_EABI__) |
| COMPILER_RT_ALIAS(__divsi3, __aeabi_idiv) |
| #endif |
