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/*
* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
* See https://llvm.org/LICENSE.txt for license information.
* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
*/
#include <sys/byteorder.h>
#define CHAR_BIT 8
typedef int di_int __attribute__((mode(DI)));
typedef unsigned int du_int __attribute__((mode(DI)));
typedef int ti_int __attribute__((mode(TI)));
typedef union {
ti_int all;
struct {
#if _LITTLE_ENDIAN
du_int low;
di_int high;
#else
di_int high;
du_int low;
#endif /* _LITTLE_ENDIAN */
} s;
} twords;
/* Returns: a * b */
static
ti_int
__mulddi3(du_int a, du_int b)
{
twords r;
const int bits_in_dword_2 = (int)(sizeof (di_int) * CHAR_BIT) / 2;
const du_int lower_mask = (du_int)~0 >> bits_in_dword_2;
r.s.low = (a & lower_mask) * (b & lower_mask);
du_int t = r.s.low >> bits_in_dword_2;
r.s.low &= lower_mask;
t += (a >> bits_in_dword_2) * (b & lower_mask);
r.s.low += (t & lower_mask) << bits_in_dword_2;
r.s.high = t >> bits_in_dword_2;
t = r.s.low >> bits_in_dword_2;
r.s.low &= lower_mask;
t += (b >> bits_in_dword_2) * (a & lower_mask);
r.s.low += (t & lower_mask) << bits_in_dword_2;
r.s.high += t >> bits_in_dword_2;
r.s.high += (a >> bits_in_dword_2) * (b >> bits_in_dword_2);
return (r.all);
}
/* Returns: a * b */
ti_int
__multi3(ti_int a, ti_int b)
{
twords x;
x.all = a;
twords y;
y.all = b;
twords r;
r.all = __mulddi3(x.s.low, y.s.low);
r.s.high += x.s.high * y.s.low + x.s.low * y.s.high;
return (r.all);
}
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