1 //===-- ashrti3.c - Implement __ashrti3 -----------------------------------===// 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements __ashrti3 for the compiler_rt library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "int_lib.h" 14 15 #ifdef CRT_HAS_128BIT 16 17 // Returns: arithmetic a >> b 18 19 // Precondition: 0 <= b < bits_in_tword 20 21 COMPILER_RT_ABI ti_int __ashrti3(ti_int a, si_int b) { 22 const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); 23 twords input; 24 twords result; 25 input.all = a; 26 if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { 27 // result.s.high = input.s.high < 0 ? -1 : 0 28 result.s.high = input.s.high >> (bits_in_dword - 1); 29 result.s.low = input.s.high >> (b - bits_in_dword); 30 } else /* 0 <= b < bits_in_dword */ { 31 if (b == 0) 32 return a; 33 result.s.high = input.s.high >> b; 34 result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); 35 } 36 return result.all; 37 } 38 39 #endif // CRT_HAS_128BIT 40