1
2#ifndef _ASM_GENERIC_DIV64_H
3#define _ASM_GENERIC_DIV64_H
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26#include <linux/types.h>
27#include <linux/compiler.h>
28
29#if BITS_PER_LONG == 64
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45# define do_div(n,base) ({ \
46 uint32_t __base = (base); \
47 uint32_t __rem; \
48 __rem = ((uint64_t)(n)) % __base; \
49 (n) = ((uint64_t)(n)) / __base; \
50 __rem; \
51 })
52
53#elif BITS_PER_LONG == 32
54
55#include <linux/log2.h>
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65#define __div64_const32(n, ___b) \
66({ \
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75 \
76 uint64_t ___res, ___x, ___t, ___m, ___n = (n); \
77 uint32_t ___p, ___bias; \
78 \
79 \
80 ___p = 1 << ilog2(___b); \
81 \
82 \
83 ___m = (~0ULL / ___b) * ___p; \
84 ___m += (((~0ULL % ___b + 1) * ___p) + ___b - 1) / ___b; \
85 \
86 \
87 ___x = ~0ULL / ___b * ___b - 1; \
88 \
89 \
90 ___res = ((___m & 0xffffffff) * (___x & 0xffffffff)) >> 32; \
91 ___t = ___res += (___m & 0xffffffff) * (___x >> 32); \
92 ___res += (___x & 0xffffffff) * (___m >> 32); \
93 ___t = (___res < ___t) ? (1ULL << 32) : 0; \
94 ___res = (___res >> 32) + ___t; \
95 ___res += (___m >> 32) * (___x >> 32); \
96 ___res /= ___p; \
97 \
98 \
99 if (~0ULL % (___b / (___b & -___b)) == 0) { \
100 \
101 ___n /= (___b & -___b); \
102 ___m = ~0ULL / (___b / (___b & -___b)); \
103 ___p = 1; \
104 ___bias = 1; \
105 } else if (___res != ___x / ___b) { \
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113 \
114 ___bias = 1; \
115 \
116 ___m = (~0ULL / ___b) * ___p; \
117 ___m += ((~0ULL % ___b + 1) * ___p) / ___b; \
118 } else { \
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123 \
124 uint32_t ___bits = -(___m & -___m); \
125 ___bits |= ___m >> 32; \
126 ___bits = (~___bits) << 1; \
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132 \
133 if (!___bits) { \
134 ___p /= (___m & -___m); \
135 ___m /= (___m & -___m); \
136 } else { \
137 ___p >>= ilog2(___bits); \
138 ___m >>= ilog2(___bits); \
139 } \
140 \
141 ___bias = 0; \
142 } \
143 \
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154 \
155 ___res = __arch_xprod_64(___m, ___n, ___bias); \
156 \
157 ___res /= ___p; \
158})
159
160#ifndef __arch_xprod_64
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171static inline uint64_t __arch_xprod_64(const uint64_t m, uint64_t n, bool bias)
172{
173 uint32_t m_lo = m;
174 uint32_t m_hi = m >> 32;
175 uint32_t n_lo = n;
176 uint32_t n_hi = n >> 32;
177 uint64_t res;
178 uint32_t res_lo, res_hi, tmp;
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180 if (!bias) {
181 res = ((uint64_t)m_lo * n_lo) >> 32;
182 } else if (!(m & ((1ULL << 63) | (1ULL << 31)))) {
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184 res = (m + (uint64_t)m_lo * n_lo) >> 32;
185 } else {
186 res = m + (uint64_t)m_lo * n_lo;
187 res_lo = res >> 32;
188 res_hi = (res_lo < m_hi);
189 res = res_lo | ((uint64_t)res_hi << 32);
190 }
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192 if (!(m & ((1ULL << 63) | (1ULL << 31)))) {
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194 res += (uint64_t)m_lo * n_hi;
195 res += (uint64_t)m_hi * n_lo;
196 res >>= 32;
197 } else {
198 res += (uint64_t)m_lo * n_hi;
199 tmp = res >> 32;
200 res += (uint64_t)m_hi * n_lo;
201 res_lo = res >> 32;
202 res_hi = (res_lo < tmp);
203 res = res_lo | ((uint64_t)res_hi << 32);
204 }
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206 res += (uint64_t)m_hi * n_hi;
207
208 return res;
209}
210#endif
211
212#ifndef __div64_32
213extern uint32_t __div64_32(uint64_t *dividend, uint32_t divisor);
214#endif
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219# define do_div(n,base) ({ \
220 uint32_t __base = (base); \
221 uint32_t __rem; \
222 (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \
223 if (__builtin_constant_p(__base) && \
224 is_power_of_2(__base)) { \
225 __rem = (n) & (__base - 1); \
226 (n) >>= ilog2(__base); \
227 } else if (__builtin_constant_p(__base) && \
228 __base != 0) { \
229 uint32_t __res_lo, __n_lo = (n); \
230 (n) = __div64_const32(n, __base); \
231 \
232 __res_lo = (n); \
233 __rem = __n_lo - __res_lo * __base; \
234 } else if (likely(((n) >> 32) == 0)) { \
235 __rem = (uint32_t)(n) % __base; \
236 (n) = (uint32_t)(n) / __base; \
237 } else { \
238 __rem = __div64_32(&(n), __base); \
239 } \
240 __rem; \
241 })
242
243#else
244
245# error do_div() does not yet support the C64
246
247#endif
248
249#endif
250