divdi3.c revision 214152
1214152Sed/* ===-- divdi3.c - Implement __divdi3 -------------------------------------=== 2214152Sed * 3214152Sed * The LLVM Compiler Infrastructure 4214152Sed * 5214152Sed * This file is distributed under the University of Illinois Open Source 6214152Sed * License. See LICENSE.TXT for details. 7214152Sed * 8214152Sed * ===----------------------------------------------------------------------=== 9214152Sed * 10214152Sed * This file implements __divdi3 for the compiler_rt library. 11214152Sed * 12214152Sed * ===----------------------------------------------------------------------=== 13214152Sed */ 14214152Sed 15214152Sed#include "int_lib.h" 16214152Sed 17214152Seddu_int __udivmoddi4(du_int a, du_int b, du_int* rem); 18214152Sed 19214152Sed/* Returns: a / b */ 20214152Sed 21214152Seddi_int 22214152Sed__divdi3(di_int a, di_int b) 23214152Sed{ 24214152Sed const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1; 25214152Sed di_int s_a = a >> bits_in_dword_m1; /* s_a = a < 0 ? -1 : 0 */ 26214152Sed di_int s_b = b >> bits_in_dword_m1; /* s_b = b < 0 ? -1 : 0 */ 27214152Sed a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 28214152Sed b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 29214152Sed s_a ^= s_b; /*sign of quotient */ 30214152Sed return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 31214152Sed} 32