1276789Sdim/* ===-- multi3.c - Implement __multi3 -------------------------------------=== 2276789Sdim * 3276789Sdim * The LLVM Compiler Infrastructure 4276789Sdim * 5276789Sdim * This file is dual licensed under the MIT and the University of Illinois Open 6276789Sdim * Source Licenses. See LICENSE.TXT for details. 7276789Sdim * 8276789Sdim * ===----------------------------------------------------------------------=== 9276789Sdim 10276789Sdim * This file implements __multi3 for the compiler_rt library. 11276789Sdim * 12276789Sdim * ===----------------------------------------------------------------------=== 13276789Sdim */ 14276789Sdim 15276789Sdim#include "int_lib.h" 16276789Sdim 17276789Sdim#ifdef CRT_HAS_128BIT 18276789Sdim 19276789Sdim/* Returns: a * b */ 20276789Sdim 21276789Sdimstatic 22276789Sdimti_int 23276789Sdim__mulddi3(du_int a, du_int b) 24276789Sdim{ 25276789Sdim twords r; 26276789Sdim const int bits_in_dword_2 = (int)(sizeof(di_int) * CHAR_BIT) / 2; 27276789Sdim const du_int lower_mask = (du_int)~0 >> bits_in_dword_2; 28276789Sdim r.s.low = (a & lower_mask) * (b & lower_mask); 29276789Sdim du_int t = r.s.low >> bits_in_dword_2; 30276789Sdim r.s.low &= lower_mask; 31276789Sdim t += (a >> bits_in_dword_2) * (b & lower_mask); 32276789Sdim r.s.low += (t & lower_mask) << bits_in_dword_2; 33276789Sdim r.s.high = t >> bits_in_dword_2; 34276789Sdim t = r.s.low >> bits_in_dword_2; 35276789Sdim r.s.low &= lower_mask; 36276789Sdim t += (b >> bits_in_dword_2) * (a & lower_mask); 37276789Sdim r.s.low += (t & lower_mask) << bits_in_dword_2; 38276789Sdim r.s.high += t >> bits_in_dword_2; 39276789Sdim r.s.high += (a >> bits_in_dword_2) * (b >> bits_in_dword_2); 40276789Sdim return r.all; 41276789Sdim} 42276789Sdim 43276789Sdim/* Returns: a * b */ 44276789Sdim 45276789SdimCOMPILER_RT_ABI ti_int 46276789Sdim__multi3(ti_int a, ti_int b) 47276789Sdim{ 48276789Sdim twords x; 49276789Sdim x.all = a; 50276789Sdim twords y; 51276789Sdim y.all = b; 52276789Sdim twords r; 53276789Sdim r.all = __mulddi3(x.s.low, y.s.low); 54276789Sdim r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; 55276789Sdim return r.all; 56276789Sdim} 57276789Sdim 58276789Sdim#endif /* CRT_HAS_128BIT */ 59