ia64/linux-2.6.18-xen.hg

view arch/powerpc/math-emu/udivmodti4.c @ 854:950b9eb27661

usbback: fix urb interval value for interrupt urbs.

Signed-off-by: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Apr 06 13:51:20 2009 +0100 (2009-04-06)
parents 831230e53067
children
line source
1 /* This has so very few changes over libgcc2's __udivmoddi4 it isn't funny. */
3 #include "soft-fp.h"
5 #undef count_leading_zeros
6 #define count_leading_zeros __FP_CLZ
8 void
9 _fp_udivmodti4(_FP_W_TYPE q[2], _FP_W_TYPE r[2],
10 _FP_W_TYPE n1, _FP_W_TYPE n0,
11 _FP_W_TYPE d1, _FP_W_TYPE d0)
12 {
13 _FP_W_TYPE q0, q1, r0, r1;
14 _FP_I_TYPE b, bm;
16 if (d1 == 0)
17 {
18 #if !UDIV_NEEDS_NORMALIZATION
19 if (d0 > n1)
20 {
21 /* 0q = nn / 0D */
23 udiv_qrnnd (q0, n0, n1, n0, d0);
24 q1 = 0;
26 /* Remainder in n0. */
27 }
28 else
29 {
30 /* qq = NN / 0d */
32 if (d0 == 0)
33 d0 = 1 / d0; /* Divide intentionally by zero. */
35 udiv_qrnnd (q1, n1, 0, n1, d0);
36 udiv_qrnnd (q0, n0, n1, n0, d0);
38 /* Remainder in n0. */
39 }
41 r0 = n0;
42 r1 = 0;
44 #else /* UDIV_NEEDS_NORMALIZATION */
46 if (d0 > n1)
47 {
48 /* 0q = nn / 0D */
50 count_leading_zeros (bm, d0);
52 if (bm != 0)
53 {
54 /* Normalize, i.e. make the most significant bit of the
55 denominator set. */
57 d0 = d0 << bm;
58 n1 = (n1 << bm) | (n0 >> (_FP_W_TYPE_SIZE - bm));
59 n0 = n0 << bm;
60 }
62 udiv_qrnnd (q0, n0, n1, n0, d0);
63 q1 = 0;
65 /* Remainder in n0 >> bm. */
66 }
67 else
68 {
69 /* qq = NN / 0d */
71 if (d0 == 0)
72 d0 = 1 / d0; /* Divide intentionally by zero. */
74 count_leading_zeros (bm, d0);
76 if (bm == 0)
77 {
78 /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
79 conclude (the most significant bit of n1 is set) /\ (the
80 leading quotient digit q1 = 1).
82 This special case is necessary, not an optimization.
83 (Shifts counts of SI_TYPE_SIZE are undefined.) */
85 n1 -= d0;
86 q1 = 1;
87 }
88 else
89 {
90 _FP_W_TYPE n2;
92 /* Normalize. */
94 b = _FP_W_TYPE_SIZE - bm;
96 d0 = d0 << bm;
97 n2 = n1 >> b;
98 n1 = (n1 << bm) | (n0 >> b);
99 n0 = n0 << bm;
101 udiv_qrnnd (q1, n1, n2, n1, d0);
102 }
104 /* n1 != d0... */
106 udiv_qrnnd (q0, n0, n1, n0, d0);
108 /* Remainder in n0 >> bm. */
109 }
111 r0 = n0 >> bm;
112 r1 = 0;
113 #endif /* UDIV_NEEDS_NORMALIZATION */
114 }
115 else
116 {
117 if (d1 > n1)
118 {
119 /* 00 = nn / DD */
121 q0 = 0;
122 q1 = 0;
124 /* Remainder in n1n0. */
125 r0 = n0;
126 r1 = n1;
127 }
128 else
129 {
130 /* 0q = NN / dd */
132 count_leading_zeros (bm, d1);
133 if (bm == 0)
134 {
135 /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
136 conclude (the most significant bit of n1 is set) /\ (the
137 quotient digit q0 = 0 or 1).
139 This special case is necessary, not an optimization. */
141 /* The condition on the next line takes advantage of that
142 n1 >= d1 (true due to program flow). */
143 if (n1 > d1 || n0 >= d0)
144 {
145 q0 = 1;
146 sub_ddmmss (n1, n0, n1, n0, d1, d0);
147 }
148 else
149 q0 = 0;
151 q1 = 0;
153 r0 = n0;
154 r1 = n1;
155 }
156 else
157 {
158 _FP_W_TYPE m1, m0, n2;
160 /* Normalize. */
162 b = _FP_W_TYPE_SIZE - bm;
164 d1 = (d1 << bm) | (d0 >> b);
165 d0 = d0 << bm;
166 n2 = n1 >> b;
167 n1 = (n1 << bm) | (n0 >> b);
168 n0 = n0 << bm;
170 udiv_qrnnd (q0, n1, n2, n1, d1);
171 umul_ppmm (m1, m0, q0, d0);
173 if (m1 > n1 || (m1 == n1 && m0 > n0))
174 {
175 q0--;
176 sub_ddmmss (m1, m0, m1, m0, d1, d0);
177 }
179 q1 = 0;
181 /* Remainder in (n1n0 - m1m0) >> bm. */
182 sub_ddmmss (n1, n0, n1, n0, m1, m0);
183 r0 = (n1 << b) | (n0 >> bm);
184 r1 = n1 >> bm;
185 }
186 }
187 }
189 q[0] = q0; q[1] = q1;
190 r[0] = r0, r[1] = r1;
191 }