1 /* ===-- divsi3.c - Implement __divsi3 -------------------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is distributed under the University of Illinois Open Source 6 * License. See LICENSE.TXT for details. 7 * 8 * ===----------------------------------------------------------------------=== 9 * 10 * This file implements __divsi3 for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #include "int_lib.h" 16 17 su_int __udivsi3(su_int n, su_int d); 18 19 /* Returns: a / b */ 20 21 si_int 22 __divsi3(si_int a, si_int b) 23 { 24 const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; 25 si_int s_a = a >> bits_in_word_m1; /* s_a = a < 0 ? -1 : 0 */ 26 si_int s_b = b >> bits_in_word_m1; /* s_b = b < 0 ? -1 : 0 */ 27 a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 28 b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 29 s_a ^= s_b; /* sign of quotient */ 30 return (__udivsi3(a, b) ^ s_a) - s_a; /* negate if s_a == -1 */ 31 } 32
