divdi3.c revision 276851
1139804Simp/* ===-- divdi3.c - Implement __divdi3 -------------------------------------=== 2885Swollman * 3885Swollman * The LLVM Compiler Infrastructure 4885Swollman * 5885Swollman * This file is dual licensed under the MIT and the University of Illinois Open 6885Swollman * Source Licenses. See LICENSE.TXT for details. 7885Swollman * 8885Swollman * ===----------------------------------------------------------------------=== 9885Swollman * 10885Swollman * This file implements __divdi3 for the compiler_rt library. 11885Swollman * 12885Swollman * ===----------------------------------------------------------------------=== 13885Swollman */ 14885Swollman 15885Swollman#include "int_lib.h" 16885Swollman 1710625Sdg/* Returns: a / b */ 18885Swollman 19885SwollmanCOMPILER_RT_ABI di_int 20885Swollman__divdi3(di_int a, di_int b) 21885Swollman{ 22885Swollman const int bits_in_dword_m1 = (int)(sizeof(di_int) * CHAR_BIT) - 1; 23885Swollman di_int s_a = a >> bits_in_dword_m1; /* s_a = a < 0 ? -1 : 0 */ 24885Swollman di_int s_b = b >> bits_in_dword_m1; /* s_b = b < 0 ? -1 : 0 */ 25885Swollman a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 26885Swollman b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 27116182Sobrien s_a ^= s_b; /*sign of quotient */ 28116182Sobrien return (__udivmoddi4(a, b, (du_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 29116182Sobrien} 302056Swollman