1 // SPDX-License-Identifier: GPL-2.0
2 /* This has so very few changes over libgcc2's __udivmoddi4 it isn't funny. */
4 #include <math-emu/soft-fp.h>
6 #undef count_leading_zeros
7 #define count_leading_zeros __FP_CLZ
10 _fp_udivmodti4(_FP_W_TYPE q[2], _FP_W_TYPE r[2],
11 _FP_W_TYPE n1, _FP_W_TYPE n0,
12 _FP_W_TYPE d1, _FP_W_TYPE d0)
14 _FP_W_TYPE q0, q1, r0, r1;
19 #if !UDIV_NEEDS_NORMALIZATION
24 udiv_qrnnd (q0, n0, n1, n0, d0);
27 /* Remainder in n0. */
34 d0 = 1 / d0; /* Divide intentionally by zero. */
36 udiv_qrnnd (q1, n1, 0, n1, d0);
37 udiv_qrnnd (q0, n0, n1, n0, d0);
39 /* Remainder in n0. */
45 #else /* UDIV_NEEDS_NORMALIZATION */
51 count_leading_zeros (bm, d0);
55 /* Normalize, i.e. make the most significant bit of the
59 n1 = (n1 << bm) | (n0 >> (_FP_W_TYPE_SIZE - bm));
63 udiv_qrnnd (q0, n0, n1, n0, d0);
66 /* Remainder in n0 >> bm. */
73 d0 = 1 / d0; /* Divide intentionally by zero. */
75 count_leading_zeros (bm, d0);
79 /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
80 conclude (the most significant bit of n1 is set) /\ (the
81 leading quotient digit q1 = 1).
83 This special case is necessary, not an optimization.
84 (Shifts counts of SI_TYPE_SIZE are undefined.) */
95 b = _FP_W_TYPE_SIZE - bm;
99 n1 = (n1 << bm) | (n0 >> b);
102 udiv_qrnnd (q1, n1, n2, n1, d0);
107 udiv_qrnnd (q0, n0, n1, n0, d0);
109 /* Remainder in n0 >> bm. */
114 #endif /* UDIV_NEEDS_NORMALIZATION */
125 /* Remainder in n1n0. */
133 count_leading_zeros (bm, d1);
136 /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
137 conclude (the most significant bit of n1 is set) /\ (the
138 quotient digit q0 = 0 or 1).
140 This special case is necessary, not an optimization. */
142 /* The condition on the next line takes advantage of that
143 n1 >= d1 (true due to program flow). */
144 if (n1 > d1 || n0 >= d0)
147 sub_ddmmss (n1, n0, n1, n0, d1, d0);
159 _FP_W_TYPE m1, m0, n2;
163 b = _FP_W_TYPE_SIZE - bm;
165 d1 = (d1 << bm) | (d0 >> b);
168 n1 = (n1 << bm) | (n0 >> b);
171 udiv_qrnnd (q0, n1, n2, n1, d1);
172 umul_ppmm (m1, m0, q0, d0);
174 if (m1 > n1 || (m1 == n1 && m0 > n0))
177 sub_ddmmss (m1, m0, m1, m0, d1, d0);
182 /* Remainder in (n1n0 - m1m0) >> bm. */
183 sub_ddmmss (n1, n0, n1, n0, m1, m0);
184 r0 = (n1 << b) | (n0 >> bm);
190 q[0] = q0; q[1] = q1;
191 r[0] = r0, r[1] = r1;