192 lines
3.4 KiB
C
192 lines
3.4 KiB
C
/* This has so very few changes over libgcc2's __udivmoddi4 it isn't funny. */
|
|
|
|
#include <math-emu/soft-fp.h>
|
|
|
|
#undef count_leading_zeros
|
|
#define count_leading_zeros __FP_CLZ
|
|
|
|
void
|
|
_fp_udivmodti4(_FP_W_TYPE q[2], _FP_W_TYPE r[2],
|
|
_FP_W_TYPE n1, _FP_W_TYPE n0,
|
|
_FP_W_TYPE d1, _FP_W_TYPE d0)
|
|
{
|
|
_FP_W_TYPE q0, q1, r0, r1;
|
|
_FP_I_TYPE b, bm;
|
|
|
|
if (d1 == 0)
|
|
{
|
|
#if !UDIV_NEEDS_NORMALIZATION
|
|
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. */
|
|
}
|
|
|
|
r0 = n0;
|
|
r1 = 0;
|
|
|
|
#else /* UDIV_NEEDS_NORMALIZATION */
|
|
|
|
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 >> (_FP_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 SI_TYPE_SIZE are undefined.) */
|
|
|
|
n1 -= d0;
|
|
q1 = 1;
|
|
}
|
|
else
|
|
{
|
|
_FP_W_TYPE n2;
|
|
|
|
/* Normalize. */
|
|
|
|
b = _FP_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. */
|
|
}
|
|
|
|
r0 = n0 >> bm;
|
|
r1 = 0;
|
|
#endif /* UDIV_NEEDS_NORMALIZATION */
|
|
}
|
|
else
|
|
{
|
|
if (d1 > n1)
|
|
{
|
|
/* 00 = nn / DD */
|
|
|
|
q0 = 0;
|
|
q1 = 0;
|
|
|
|
/* Remainder in n1n0. */
|
|
r0 = n0;
|
|
r1 = n1;
|
|
}
|
|
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;
|
|
|
|
r0 = n0;
|
|
r1 = n1;
|
|
}
|
|
else
|
|
{
|
|
_FP_W_TYPE m1, m0, n2;
|
|
|
|
/* Normalize. */
|
|
|
|
b = _FP_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. */
|
|
sub_ddmmss (n1, n0, n1, n0, m1, m0);
|
|
r0 = (n1 << b) | (n0 >> bm);
|
|
r1 = n1 >> bm;
|
|
}
|
|
}
|
|
}
|
|
|
|
q[0] = q0; q[1] = q1;
|
|
r[0] = r0, r[1] = r1;
|
|
}
|