divti3.c revision 239138
117829Spst/* ===-- divti3.c - Implement __divti3 -------------------------------------=== 237Srgrimes * 337Srgrimes * The LLVM Compiler Infrastructure 4204Snate * 52878Srgrimes * This file is dual licensed under the MIT and the University of Illinois Open 68571Srgrimes * Source Licenses. See LICENSE.TXT for details. 72878Srgrimes * 88571Srgrimes * ===----------------------------------------------------------------------=== 98571Srgrimes * 108571Srgrimes * This file implements __divti3 for the compiler_rt library. 112878Srgrimes * 128571Srgrimes * ===----------------------------------------------------------------------=== 138571Srgrimes */ 142878Srgrimes 158571Srgrimes#include "int_lib.h" 162878Srgrimes 178571Srgrimes#if __x86_64 182878Srgrimes 192878Srgrimestu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); 202878Srgrimes 218571Srgrimes/* Returns: a / b */ 222878Srgrimes 232878Srgrimesti_int 242878Srgrimes__divti3(ti_int a, ti_int b) 252878Srgrimes{ 262878Srgrimes const int bits_in_tword_m1 = (int)(sizeof(ti_int) * CHAR_BIT) - 1; 278571Srgrimes ti_int s_a = a >> bits_in_tword_m1; /* s_a = a < 0 ? -1 : 0 */ 288571Srgrimes ti_int s_b = b >> bits_in_tword_m1; /* s_b = b < 0 ? -1 : 0 */ 292878Srgrimes a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 308571Srgrimes b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 312878Srgrimes s_a ^= s_b; /* sign of quotient */ 322878Srgrimes return (__udivmodti4(a, b, (tu_int*)0) ^ s_a) - s_a; /* negate if s_a == -1 */ 332878Srgrimes} 342878Srgrimes 352878Srgrimes#endif 362878Srgrimes