1/*
2 * Floating point arithmetic implementation
3 *
4 * The code in this source file is derived from release 2a of the SoftFloat
5 * IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and
6 * some later contributions) are provided under that license, as detailed below.
7 * It has subsequently been modified by contributors to the QEMU Project,
8 * so some portions are provided under:
9 *  the SoftFloat-2a license
10 *  the BSD license
11 *  GPL-v2-or-later
12 *
13 * Any future contributions to this file after December 1st 2014 will be
14 * taken to be licensed under the Softfloat-2a license unless specifically
15 * indicated otherwise.
16 */
17
18static void partsN(add_normal)(FloatPartsN *a, FloatPartsN *b)
19{
20    int exp_diff = a->exp - b->exp;
21
22    if (exp_diff > 0) {
23        frac_shrjam(b, exp_diff);
24    } else if (exp_diff < 0) {
25        frac_shrjam(a, -exp_diff);
26        a->exp = b->exp;
27    }
28
29    if (frac_add(a, a, b)) {
30        frac_shrjam(a, 1);
31        a->frac_hi |= DECOMPOSED_IMPLICIT_BIT;
32        a->exp += 1;
33    }
34}
35
36static bool partsN(sub_normal)(FloatPartsN *a, FloatPartsN *b)
37{
38    int exp_diff = a->exp - b->exp;
39    int shift;
40
41    if (exp_diff > 0) {
42        frac_shrjam(b, exp_diff);
43        frac_sub(a, a, b);
44    } else if (exp_diff < 0) {
45        a->exp = b->exp;
46        a->sign ^= 1;
47        frac_shrjam(a, -exp_diff);
48        frac_sub(a, b, a);
49    } else if (frac_sub(a, a, b)) {
50        /* Overflow means that A was less than B. */
51        frac_neg(a);
52        a->sign ^= 1;
53    }
54
55    shift = frac_normalize(a);
56    if (likely(shift < N)) {
57        a->exp -= shift;
58	return true;
59    }
60    a->cls = float_class_zero;
61    return false;
62}
63