1214152Sed/* ===-- divsi3.c - Implement __divsi3 -------------------------------------=== 2214152Sed * 3214152Sed * The LLVM Compiler Infrastructure 4214152Sed * 5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open 6222656Sed * Source Licenses. See LICENSE.TXT for details. 7214152Sed * 8214152Sed * ===----------------------------------------------------------------------=== 9214152Sed * 10214152Sed * This file implements __divsi3 for the compiler_rt library. 11214152Sed * 12214152Sed * ===----------------------------------------------------------------------=== 13214152Sed */ 14214152Sed 15214152Sed#include "int_lib.h" 16214152Sed 17222656Sedsu_int COMPILER_RT_ABI __udivsi3(su_int n, su_int d); 18214152Sed 19214152Sed/* Returns: a / b */ 20214152Sed 21239138SandrewARM_EABI_FNALIAS(idiv, divsi3) 22222656Sed 23222656SedCOMPILER_RT_ABI si_int 24214152Sed__divsi3(si_int a, si_int b) 25214152Sed{ 26214152Sed const int bits_in_word_m1 = (int)(sizeof(si_int) * CHAR_BIT) - 1; 27214152Sed si_int s_a = a >> bits_in_word_m1; /* s_a = a < 0 ? -1 : 0 */ 28214152Sed si_int s_b = b >> bits_in_word_m1; /* s_b = b < 0 ? -1 : 0 */ 29214152Sed a = (a ^ s_a) - s_a; /* negate if s_a == -1 */ 30214152Sed b = (b ^ s_b) - s_b; /* negate if s_b == -1 */ 31214152Sed s_a ^= s_b; /* sign of quotient */ 32239138Sandrew /* 33239138Sandrew * On CPUs without unsigned hardware division support, 34239138Sandrew * this calls __udivsi3 (notice the cast to su_int). 35239138Sandrew * On CPUs with unsigned hardware division support, 36239138Sandrew * this uses the unsigned division instruction. 37239138Sandrew */ 38239138Sandrew return ((su_int)a/(su_int)b ^ s_a) - s_a; /* negate if s_a == -1 */ 39214152Sed} 40