1*0a23da6dSjca /* ===-- multi3.c - Implement __multi3 -------------------------------------=== 2*0a23da6dSjca * 3*0a23da6dSjca * The LLVM Compiler Infrastructure 4*0a23da6dSjca * 5*0a23da6dSjca * This file is dual licensed under the MIT and the University of Illinois Open 6*0a23da6dSjca * Source Licenses. See LICENSE.TXT for details. 7*0a23da6dSjca * 8*0a23da6dSjca * ===----------------------------------------------------------------------=== 9*0a23da6dSjca 10*0a23da6dSjca * This file implements __multi3 for the compiler_rt library. 11*0a23da6dSjca * 12*0a23da6dSjca * ===----------------------------------------------------------------------=== 13*0a23da6dSjca */ 14*0a23da6dSjca 15*0a23da6dSjca #include "crt_glue.h" 16*0a23da6dSjca 17*0a23da6dSjca /* Returns: a * b */ 18*0a23da6dSjca 19*0a23da6dSjca static 20*0a23da6dSjca ti_int __mulddi3(du_int a,du_int b)21*0a23da6dSjca__mulddi3(du_int a, du_int b) 22*0a23da6dSjca { 23*0a23da6dSjca twords r; 24*0a23da6dSjca const int bits_in_dword_2 = (int)(sizeof(di_int) * CHAR_BIT) / 2; 25*0a23da6dSjca const du_int lower_mask = (du_int)~0 >> bits_in_dword_2; 26*0a23da6dSjca r.s.low = (a & lower_mask) * (b & lower_mask); 27*0a23da6dSjca du_int t = r.s.low >> bits_in_dword_2; 28*0a23da6dSjca r.s.low &= lower_mask; 29*0a23da6dSjca t += (a >> bits_in_dword_2) * (b & lower_mask); 30*0a23da6dSjca r.s.low += (t & lower_mask) << bits_in_dword_2; 31*0a23da6dSjca r.s.high = t >> bits_in_dword_2; 32*0a23da6dSjca t = r.s.low >> bits_in_dword_2; 33*0a23da6dSjca r.s.low &= lower_mask; 34*0a23da6dSjca t += (b >> bits_in_dword_2) * (a & lower_mask); 35*0a23da6dSjca r.s.low += (t & lower_mask) << bits_in_dword_2; 36*0a23da6dSjca r.s.high += t >> bits_in_dword_2; 37*0a23da6dSjca r.s.high += (a >> bits_in_dword_2) * (b >> bits_in_dword_2); 38*0a23da6dSjca return r.all; 39*0a23da6dSjca } 40*0a23da6dSjca 41*0a23da6dSjca /* Returns: a * b */ 42*0a23da6dSjca 43*0a23da6dSjca ti_int __multi3(ti_int a,ti_int b)44*0a23da6dSjca__multi3(ti_int a, ti_int b) 45*0a23da6dSjca { 46*0a23da6dSjca twords x; 47*0a23da6dSjca x.all = a; 48*0a23da6dSjca twords y; 49*0a23da6dSjca y.all = b; 50*0a23da6dSjca twords r; 51*0a23da6dSjca r.all = __mulddi3(x.s.low, y.s.low); 52*0a23da6dSjca r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; 53*0a23da6dSjca return r.all; 54*0a23da6dSjca } 55