1156cd587Sjoerg /* ===-- divsi3.c - Implement __divsi3 -------------------------------------=== 2156cd587Sjoerg * 3156cd587Sjoerg * The LLVM Compiler Infrastructure 4156cd587Sjoerg * 5156cd587Sjoerg * This file is dual licensed under the MIT and the University of Illinois Open 6156cd587Sjoerg * Source Licenses. See LICENSE.TXT for details. 7156cd587Sjoerg * 8156cd587Sjoerg * ===----------------------------------------------------------------------=== 9156cd587Sjoerg * 10156cd587Sjoerg * This file implements __divsi3 for the compiler_rt library. 11156cd587Sjoerg * 12156cd587Sjoerg * ===----------------------------------------------------------------------=== 13156cd587Sjoerg */ 14156cd587Sjoerg 15156cd587Sjoerg #include "int_lib.h" 16156cd587Sjoerg 17156cd587Sjoerg /* Returns: a / b */ 18156cd587Sjoerg 19156cd587Sjoerg COMPILER_RT_ABI si_int __divsi3(si_int a,si_int b)20156cd587Sjoerg__divsi3(si_int a, si_int b) 21156cd587Sjoerg { 22156cd587Sjoerg const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; 23156cd587Sjoerg si_int s_a = a >> bits_in_word_m1; /* s_a = a < 0 ? -1 : 0 */ 24156cd587Sjoerg si_int s_b = b >> bits_in_word_m1; /* s_b = b < 0 ? -1 : 0 */ 25156cd587Sjoerg a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 26156cd587Sjoerg b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 27156cd587Sjoerg s_a ^= s_b; /* sign of quotient */ 28156cd587Sjoerg /* 29156cd587Sjoerg * On CPUs without unsigned hardware division support, 30156cd587Sjoerg * this calls __udivsi3 (notice the cast to su_int). 31156cd587Sjoerg * On CPUs with unsigned hardware division support, 32156cd587Sjoerg * this uses the unsigned division instruction. 33156cd587Sjoerg */ 34156cd587Sjoerg return ((su_int)a/(su_int)b ^ s_a) - s_a; /* negate if s_a == -1 */ 35156cd587Sjoerg } 363044ee7eSrin 373044ee7eSrin #if defined(__ARM_EABI__) 38*d3143459Srin AEABI_RTABI si_int __aeabi_idiv(si_int a, si_int b) COMPILER_RT_ALIAS(__divsi3); 393044ee7eSrin #endif 40