divti3.c revision 2bf62728b8ce00e295c7bf0fb328427496cc85aa
12bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan/* ===-- divti3.c - Implement __divti3 -------------------------------------=== 22bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 32bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * The LLVM Compiler Infrastructure 42bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 52bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * This file is distributed under the University of Illinois Open Source 62bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * License. See LICENSE.TXT for details. 72bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 82bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * ===----------------------------------------------------------------------=== 92bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 102bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * This file implements __divti3 for the compiler_rt library. 112bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * 122bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan * ===----------------------------------------------------------------------=== 132bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan */ 14b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 15b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#if __x86_64 16b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 17b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#include "int_lib.h" 18b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 19b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbartu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); 20b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 212bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan/* Returns: a / b */ 22b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 23b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbarti_int 24b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar__divti3(ti_int a, ti_int b) 25b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar{ 26b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1; 272bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan ti_int s_a = a >> bits_in_tword_m1; /* s_a = a < 0 ? -1 : 0 */ 282bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan ti_int s_b = b >> bits_in_tword_m1; /* s_b = b < 0 ? -1 : 0 */ 292bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 302bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 312bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan s_a ^= s_b; /* sign of quotient */ 322bf62728b8ce00e295c7bf0fb328427496cc85aaEdward O'Callaghan return (__udivmodti4(a, b, (tu_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 33b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar} 34b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 35b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#endif 36