divdi3.c revision 37a6a455466e5b197311771a777ab241e471ed8a
137a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan/* ===-- divdi3.c - Implement __divdi3 -------------------------------------=== 237a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * 337a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * The LLVM Compiler Infrastructure 437a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * 537a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * This file is distributed under the University of Illinois Open Source 637a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * License. See LICENSE.TXT for details. 737a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * 837a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * ===----------------------------------------------------------------------=== 937a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * 1037a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * This file implements __divdi3 for the compiler_rt library. 1137a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * 1237a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan * ===----------------------------------------------------------------------=== 1337a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan */ 14b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 15b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar#include "int_lib.h" 16b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 17b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbardu_int __udivmoddi4(du_int a, du_int b, du_int* rem); 18b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 1937a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan/* Returns: a / b */ 20b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar 21b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbardi_int 22b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar__divdi3(di_int a, di_int b) 23b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar{ 24b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1; 2537a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan di_int s_a = a >> bits_in_dword_m1; /* s_a = a < 0 ? -1 : 0 */ 2637a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan di_int s_b = b >> bits_in_dword_m1; /* s_b = b < 0 ? -1 : 0 */ 2737a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 2837a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 2937a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan s_a ^= s_b; /*sign of quotient */ 3037a6a455466e5b197311771a777ab241e471ed8aEdward O'Callaghan return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 31b3a6901e66f55b35aa9e01bcb24134e6a65ea004Daniel Dunbar} 32