muldi3.c revision 222656
1259701Sdim/* ===-- muldi3.c - Implement __muldi3 -------------------------------------=== 2259701Sdim * 3259701Sdim * The LLVM Compiler Infrastructure 4259701Sdim * 5259701Sdim * This file is dual licensed under the MIT and the University of Illinois Open 6259701Sdim * Source Licenses. See LICENSE.TXT for details. 7259701Sdim * 8259701Sdim * ===----------------------------------------------------------------------=== 9259701Sdim * 10259701Sdim * This file implements __muldi3 for the compiler_rt library. 11259701Sdim * 12259701Sdim * ===----------------------------------------------------------------------=== 13259701Sdim */ 14259701Sdim#include "abi.h" 15259701Sdim 16259701Sdim#include "int_lib.h" 17259701Sdim 18259701Sdim/* Returns: a * b */ 19259701Sdim 20259701Sdimstatic 21259701Sdimdi_int 22259701Sdim__muldsi3(su_int a, su_int b) 23259701Sdim{ 24259701Sdim dwords r; 25259701Sdim const int bits_in_word_2 = (int)(sizeof(si_int) * CHAR_BIT) / 2; 26259701Sdim const su_int lower_mask = (su_int)~0 >> bits_in_word_2; 27259701Sdim r.s.low = (a & lower_mask) * (b & lower_mask); 28259701Sdim su_int t = r.s.low >> bits_in_word_2; 29259701Sdim r.s.low &= lower_mask; 30259701Sdim t += (a >> bits_in_word_2) * (b & lower_mask); 31259701Sdim r.s.low += (t & lower_mask) << bits_in_word_2; 32259701Sdim r.s.high = t >> bits_in_word_2; 33259701Sdim t = r.s.low >> bits_in_word_2; 34259701Sdim r.s.low &= lower_mask; 35259701Sdim t += (b >> bits_in_word_2) * (a & lower_mask); 36259701Sdim r.s.low += (t & lower_mask) << bits_in_word_2; 37259701Sdim r.s.high += t >> bits_in_word_2; 38259701Sdim r.s.high += (a >> bits_in_word_2) * (b >> bits_in_word_2); 39259701Sdim return r.all; 40259701Sdim} 41259701Sdim 42259701Sdim/* Returns: a * b */ 43259701Sdim 44259701SdimARM_EABI_FNALIAS(lmul, muldi3); 45259701Sdim 46259701SdimCOMPILER_RT_ABI di_int 47259701Sdim__muldi3(di_int a, di_int b) 48259701Sdim{ 49259701Sdim dwords x; 50259701Sdim x.all = a; 51259701Sdim dwords y; 52259701Sdim y.all = b; 53259701Sdim dwords r; 54259701Sdim r.all = __muldsi3(x.s.low, y.s.low); 55259701Sdim r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; 56259701Sdim return r.all; 57259701Sdim} 58259701Sdim