12bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan/* ===-- lshrdi3.c - Implement __lshrdi3 -----------------------------------=== 22bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 32bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * The LLVM Compiler Infrastructure 42bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 59ad441ffec97db647fee3725b3424284fb913e14Howard Hinnant * This file is dual licensed under the MIT and the University of Illinois Open 69ad441ffec97db647fee3725b3424284fb913e14Howard Hinnant * Source Licenses. See LICENSE.TXT for details. 72bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 82bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * ===----------------------------------------------------------------------=== 92bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 102bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * This file implements __lshrdi3 for the compiler_rt library. 112bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 122bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * ===----------------------------------------------------------------------=== 132bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan */ 14b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 15b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#include "int_lib.h" 16b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 172bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan/* Returns: logical a >> b */ 18b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 192bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan/* Precondition: 0 <= b < bits_in_dword */ 20b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 210193b74976719b8aea4cb8874ba36b75836a8d6eChandler CarruthARM_EABI_FNALIAS(llsr, lshrdi3) 2237b97d1cf4501b94347e0b4e880f4b25825a289fAnton Korobeynikov 231c5f89b1dd741135a4007ab577723d422f421eecAnton KorobeynikovCOMPILER_RT_ABI di_int 24b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar__lshrdi3(di_int a, si_int b) 25b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar{ 26b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar const int bits_in_word = (int)(sizeof(si_int) * CHAR_BIT); 27b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar udwords input; 28b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar udwords result; 29b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar input.all = a; 302bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan if (b & bits_in_word) /* bits_in_word <= b < bits_in_dword */ 31b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar { 328bf1e094893cb24796137b47ee0d46d18d299996Edward O'Callaghan result.s.high = 0; 338bf1e094893cb24796137b47ee0d46d18d299996Edward O'Callaghan result.s.low = input.s.high >> (b - bits_in_word); 34b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar } 352bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan else /* 0 <= b < bits_in_word */ 36b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar { 37b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar if (b == 0) 38b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return a; 398bf1e094893cb24796137b47ee0d46d18d299996Edward O'Callaghan result.s.high = input.s.high >> b; 408bf1e094893cb24796137b47ee0d46d18d299996Edward O'Callaghan result.s.low = (input.s.high << (bits_in_word - b)) | (input.s.low >> b); 41b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar } 42b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar return result.all; 43b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar} 44