1 /* ===-- divdi3.c - Implement __divdi3 -------------------------------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is dual licensed under the MIT and the University of Illinois Open 6 * Source Licenses. See LICENSE.TXT for details. 7 * 8 * ===----------------------------------------------------------------------=== 9 * 10 * This file implements __divdi3 for the compiler_rt library. 11 * 12 * ===----------------------------------------------------------------------=== 13 */ 14 15 #include "int_lib.h" 16 17 du_int COMPILER_RT_ABI __udivmoddi4(du_int a, du_int b, du_int* rem); 18 19 /* Returns: a / b */ 20 21 COMPILER_RT_ABI di_int 22 __divdi3(di_int a, di_int b) 23 { 24 const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1; 25 di_int s_a = a >> bits_in_dword_m1; /* s_a = a < 0 ? -1 : 0 */ 26 di_int s_b = b >> bits_in_dword_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 (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 31 } 32
