1 /* 2 * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 3 * See https://llvm.org/LICENSE.txt for license information. 4 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 5 */ 6 7 #include <sys/byteorder.h> 8 9 #define CHAR_BIT 8 10 11 typedef int di_int __attribute__((mode(DI))); 12 typedef unsigned int du_int __attribute__((mode(DI))); 13 typedef int ti_int __attribute__((mode(TI))); 14 15 typedef union { 16 ti_int all; 17 struct { 18 #if _LITTLE_ENDIAN 19 du_int low; 20 di_int high; 21 #else 22 di_int high; 23 du_int low; 24 #endif /* _LITTLE_ENDIAN */ 25 } s; 26 } twords; 27 28 /* Returns: a * b */ 29 static 30 ti_int 31 __mulddi3(du_int a, du_int b) 32 { 33 twords r; 34 const int bits_in_dword_2 = (int)(sizeof (di_int) * CHAR_BIT) / 2; 35 const du_int lower_mask = (du_int)~0 >> bits_in_dword_2; 36 r.s.low = (a & lower_mask) * (b & lower_mask); 37 du_int t = r.s.low >> bits_in_dword_2; 38 r.s.low &= lower_mask; 39 t += (a >> bits_in_dword_2) * (b & lower_mask); 40 r.s.low += (t & lower_mask) << bits_in_dword_2; 41 r.s.high = t >> bits_in_dword_2; 42 t = r.s.low >> bits_in_dword_2; 43 r.s.low &= lower_mask; 44 t += (b >> bits_in_dword_2) * (a & lower_mask); 45 r.s.low += (t & lower_mask) << bits_in_dword_2; 46 r.s.high += t >> bits_in_dword_2; 47 r.s.high += (a >> bits_in_dword_2) * (b >> bits_in_dword_2); 48 return (r.all); 49 } 50 51 /* Returns: a * b */ 52 ti_int 53 __multi3(ti_int a, ti_int b) 54 { 55 twords x; 56 x.all = a; 57 twords y; 58 y.all = b; 59 twords r; 60 r.all = __mulddi3(x.s.low, y.s.low); 61 r.s.high += x.s.high * y.s.low + x.s.low * y.s.high; 62 return (r.all); 63 } 64