muldi3.c revision 222656
1219019Sgabor/* ===-- muldi3.c - Implement __muldi3 -------------------------------------=== 2219019Sgabor * 3219019Sgabor * The LLVM Compiler Infrastructure 4219019Sgabor * 5219019Sgabor * This file is dual licensed under the MIT and the University of Illinois Open 6219019Sgabor * Source Licenses. See LICENSE.TXT for details. 7219019Sgabor * 8219019Sgabor * ===----------------------------------------------------------------------=== 9222354Sgabor * 10222354Sgabor * This file implements __muldi3 for the compiler_rt library. 11222354Sgabor * 12222354Sgabor * ===----------------------------------------------------------------------=== 13222354Sgabor */ 14222354Sgabor#include "abi.h" 15222354Sgabor 16222354Sgabor#include "int_lib.h" 17222354Sgabor 18222354Sgabor/* Returns: a * b */ 19222354Sgabor 20252458Speterstatic 21254273Speterdi_int 22252458Speter__muldsi3(su_int a, su_int b) 23252458Speter{ 24252458Speter dwords r; 25252458Speter const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2; 26252458Speter const su_int lower_mask = (su_int)~0 >> bits_in_word_2; 27252458Speter r.s.low = (a & lower_mask) * (b & lower_mask); 28252458Speter su_int t = r.s.low >> bits_in_word_2; 29252458Speter r.s.low &= lower_mask; 30252458Speter t += (a >> bits_in_word_2) * (b & lower_mask); 31222354Sgabor r.s.low += (t & lower_mask) << bits_in_word_2; 32219019Sgabor r.s.high = t >> bits_in_word_2; 33219019Sgabor t = r.s.low >> bits_in_word_2; 34219019Sgabor r.s.low &= lower_mask; 35219019Sgabor t += (b >> bits_in_word_2) * (a & lower_mask); 36219019Sgabor r.s.low += (t & lower_mask) << bits_in_word_2; 37219019Sgabor r.s.high += t >> bits_in_word_2; 38219019Sgabor r.s.high += (a >> bits_in_word_2) * (b >> bits_in_word_2); 39219019Sgabor return r.all; 40219019Sgabor} 41219019Sgabor 42219019Sgabor/* Returns: a * b */ 43219019Sgabor 44219019SgaborARM_EABI_FNALIAS(lmul, muldi3); 45219019Sgabor 46219019SgaborCOMPILER_RT_ABI di_int 47219019Sgabor__muldi3(di_int a, di_int b) 48219019Sgabor{ 49219019Sgabor dwords x; 50219019Sgabor x.all = a; 51219019Sgabor dwords y; 52219019Sgabor y.all = b; 53254285Speter dwords r; 54219019Sgabor r.all = __muldsi3(x.s.low, y.s.low); 55219019Sgabor r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; 56219019Sgabor return r.all; 57219019Sgabor} 58219019Sgabor