/* 64-bit multiplication and division
Copyright (C) 1989, 1992-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <endian.h>
#include <stdlib.h>
#include <bits/wordsize.h>
#if __WORDSIZE != 32
#error This is for 32-bit targets only
#endif
typedef unsigned int UQItype __attribute__ ((mode (QI)));
typedef int SItype __attribute__ ((mode (SI)));
typedef unsigned int USItype __attribute__ ((mode (SI)));
typedef int DItype __attribute__ ((mode (DI)));
typedef unsigned int UDItype __attribute__ ((mode (DI)));
#define Wtype SItype
#define HWtype SItype
#define DWtype DItype
#define UWtype USItype
#define UHWtype USItype
#define UDWtype UDItype
#define W_TYPE_SIZE 32
#include <stdlib/longlong.h>
#if __BYTE_ORDER == __BIG_ENDIAN
struct DWstruct { Wtype high, low;};
#elif __BYTE_ORDER == __LITTLE_ENDIAN
struct DWstruct { Wtype low, high;};
#else
#error Unhandled endianity
#endif
typedef union { struct DWstruct s; DWtype ll; } DWunion;
/* Prototypes of exported functions. */
extern DWtype __divdi3 (DWtype u, DWtype v);
extern DWtype __moddi3 (DWtype u, DWtype v);
extern UDWtype __udivdi3 (UDWtype u, UDWtype v);
extern UDWtype __umoddi3 (UDWtype u, UDWtype v);
static UDWtype
__udivmoddi4 (UDWtype n, UDWtype d, UDWtype *rp)
{
DWunion ww;
DWunion nn, dd;
DWunion rr;
UWtype d0, d1, n0, n1, n2;
UWtype q0, q1;
UWtype b, bm;
nn.ll = n;
dd.ll = d;
d0 = dd.s.low;
d1 = dd.s.high;
n0 = nn.s.low;
n1 = nn.s.high;
#if !UDIV_NEEDS_NORMALIZATION
if (d1 == 0)
{
if (d0 > n1)
{
/* 0q = nn / 0D */
udiv_qrnnd (q0, n0, n1, n0, d0);
q1 = 0;
/* Remainder in n0. */
}
else
{
/* qq = NN / 0d */
if (d0 == 0)
d0 = 1 / d0; /* Divide intentionally by zero. */
udiv_qrnnd (q1, n1, 0, n1, d0);
udiv_qrnnd (q0, n0, n1, n0, d0);
/* Remainder in n0. */
}
if (rp != 0)
{
rr.s.low = n0;
rr.s.high = 0;
*rp = rr.ll;
}
}
#else /* UDIV_NEEDS_NORMALIZATION */
if (d1 == 0)
{
if (d0 > n1)
{
/* 0q = nn / 0D */
count_leading_zeros (bm, d0);
if (bm != 0)
{
/* Normalize, i.e. make the most significant bit of the
denominator set. */
d0 = d0 << bm;
n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
n0 = n0 << bm;
}
udiv_qrnnd (q0, n0, n1, n0, d0);
q1 = 0;
/* Remainder in n0 >> bm. */
}
else
{
/* qq = NN / 0d */
if (d0 == 0)
d0 = 1 / d0; /* Divide intentionally by zero. */
count_leading_zeros (bm, d0);
if (bm == 0)
{
/* From (n1 >= d0) /\ (the most significant bit of d0 is set),
conclude (the most significant bit of n1 is set) /\ (the
leading quotient digit q1 = 1).
This special case is necessary, not an optimization.
(Shifts counts of W_TYPE_SIZE are undefined.) */
n1 -= d0;
q1 = 1;
}
else
{
/* Normalize. */
b = W_TYPE_SIZE - bm;
d0 = d0 << bm;
n2 = n1 >> b;
n1 = (n1 << bm) | (n0 >> b);
n0 = n0 << bm;
udiv_qrnnd (q1, n1, n2, n1, d0);
}
/* n1 != d0... */
udiv_qrnnd (q0, n0, n1, n0, d0);
/* Remainder in n0 >> bm. */
}
if (rp != 0)
{
rr.s.low = n0 >> bm;
rr.s.high = 0;
*rp = rr.ll;
}
}
#endif /* UDIV_NEEDS_NORMALIZATION */
else
{
if (d1 > n1)
{
/* 00 = nn / DD */
q0 = 0;
q1 = 0;
/* Remainder in n1n0. */
if (rp != 0)
{
rr.s.low = n0;
rr.s.high = n1;
*rp = rr.ll;
}
}
else
{
/* 0q = NN / dd */
count_leading_zeros (bm, d1);
if (bm == 0)
{
/* From (n1 >= d1) /\ (the most significant bit of d1 is set),
conclude (the most significant bit of n1 is set) /\ (the
quotient digit q0 = 0 or 1).
This special case is necessary, not an optimization. */
/* The condition on the next line takes advantage of that
n1 >= d1 (true due to program flow). */
if (n1 > d1 || n0 >= d0)
{
q0 = 1;
sub_ddmmss (n1, n0, n1, n0, d1, d0);
}
else
q0 = 0;
q1 = 0;
if (rp != 0)
{
rr.s.low = n0;
rr.s.high = n1;
*rp = rr.ll;
}
}
else
{
UWtype m1, m0;
/* Normalize. */
b = W_TYPE_SIZE - bm;
d1 = (d1 << bm) | (d0 >> b);
d0 = d0 << bm;
n2 = n1 >> b;
n1 = (n1 << bm) | (n0 >> b);
n0 = n0 << bm;
udiv_qrnnd (q0, n1, n2, n1, d1);
umul_ppmm (m1, m0, q0, d0);
if (m1 > n1 || (m1 == n1 && m0 > n0))
{
q0--;
sub_ddmmss (m1, m0, m1, m0, d1, d0);
}
q1 = 0;
/* Remainder in (n1n0 - m1m0) >> bm. */
if (rp != 0)
{
sub_ddmmss (n1, n0, n1, n0, m1, m0);
rr.s.low = (n1 << b) | (n0 >> bm);
rr.s.high = n1 >> bm;
*rp = rr.ll;
}
}
}
}
ww.s.low = q0;
ww.s.high = q1;
return ww.ll;
}
DWtype
__divdi3 (DWtype u, DWtype v)
{
Wtype c = 0;
DWtype w;
if (u < 0)
{
c = ~c;
u = -u;
}
if (v < 0)
{
c = ~c;
v = -v;
}
w = __udivmoddi4 (u, v, NULL);
if (c)
w = -w;
return w;
}
strong_alias (__divdi3, __divdi3_internal)
DWtype
__moddi3 (DWtype u, DWtype v)
{
Wtype c = 0;
DWtype w;
if (u < 0)
{
c = ~c;
u = -u;
}
if (v < 0)
v = -v;
__udivmoddi4 (u, v, (UDWtype *) &w);
if (c)
w = -w;
return w;
}
strong_alias (__moddi3, __moddi3_internal)
UDWtype
__udivdi3 (UDWtype u, UDWtype v)
{
return __udivmoddi4 (u, v, NULL);
}
strong_alias (__udivdi3, __udivdi3_internal)
UDWtype
__umoddi3 (UDWtype u, UDWtype v)
{
UDWtype w;
__udivmoddi4 (u, v, &w);
return w;
}
strong_alias (__umoddi3, __umoddi3_internal)
/* We declare these with compat_symbol so that they are not visible at
link time. Programs must use the functions from libgcc. */
#ifdef SHARED
# include <shlib-compat.h>
compat_symbol (libc, __divdi3, __divdi3, GLIBC_2_0);
compat_symbol (libc, __moddi3, __moddi3, GLIBC_2_0);
compat_symbol (libc, __udivdi3, __udivdi3, GLIBC_2_0);
compat_symbol (libc, __umoddi3, __umoddi3, GLIBC_2_0);
#endif