divdi3.c revision 214152
1238106Sdes/* ===-- divdi3.c - Implement __divdi3 -------------------------------------=== 2238106Sdes * 3238106Sdes * The LLVM Compiler Infrastructure 4238106Sdes * 5238106Sdes * This file is distributed under the University of Illinois Open Source 6238106Sdes * License. See LICENSE.TXT for details. 7238106Sdes * 8238106Sdes * ===----------------------------------------------------------------------=== 9238106Sdes * 10238106Sdes * This file implements __divdi3 for the compiler_rt library. 11238106Sdes * 12238106Sdes * ===----------------------------------------------------------------------=== 13238106Sdes */ 14238106Sdes 15238106Sdes#include "int_lib.h" 16238106Sdes 17238106Sdesdu_int __udivmoddi4(du_int a, du_int b, du_int* rem); 18238106Sdes 19238106Sdes/* Returns: a / b */ 20238106Sdes 21238106Sdesdi_int 22238106Sdes__divdi3(di_int a, di_int b) 23238106Sdes{ 24266114Sdes const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1; 25266114Sdes di_int s_a = a >> bits_in_dword_m1; /* s_a = a < 0 ? -1 : 0 */ 26266114Sdes di_int s_b = b >> bits_in_dword_m1; /* s_b = b < 0 ? -1 : 0 */ 27266114Sdes a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 28266114Sdes b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 29266114Sdes s_a ^= s_b; /*sign of quotient */ 30266114Sdes return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 31266114Sdes} 32266114Sdes