1 //===-- lshrti3.c - Implement __lshrti3 -----------------------------------===// 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 __lshrti3 for the compiler_rt library. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "int_lib.h" 14 15 #ifdef CRT_HAS_128BIT 16 17 // Returns: logical a >> b 18 19 // Precondition: 0 <= b < bits_in_tword 20 21 COMPILER_RT_ABI ti_int __lshrti3(ti_int a, int b) { 22 const int bits_in_dword = (int)(sizeof(di_int) * CHAR_BIT); 23 utwords input; 24 utwords result; 25 input.all = a; 26 if (b & bits_in_dword) /* bits_in_dword <= b < bits_in_tword */ { 27 result.s.high = 0; 28 result.s.low = input.s.high >> (b - bits_in_dword); 29 } else /* 0 <= b < bits_in_dword */ { 30 if (b == 0) 31 return a; 32 result.s.high = input.s.high >> b; 33 result.s.low = (input.s.high << (bits_in_dword - b)) | (input.s.low >> b); 34 } 35 return result.all; 36 } 37 38 #endif // CRT_HAS_128BIT 39