1 // Copyright 2017 The PDFium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6
7 #include "xfa/fgas/crt/cfgas_decimal.h"
8
9 #include <math.h>
10
11 #include <algorithm>
12 #include <limits>
13 #include <utility>
14
15 #include "core/fxcrt/fx_extension.h"
16 #include "third_party/base/check.h"
17
18 #define FXMATH_DECIMAL_SCALELIMIT 0x1c
19 #define FXMATH_DECIMAL_RSHIFT32BIT(x) ((x) >> 0x10 >> 0x10)
20 #define FXMATH_DECIMAL_LSHIFT32BIT(x) ((x) << 0x10 << 0x10)
21
22 namespace {
23
decimal_helper_div10(uint64_t & phi,uint64_t & pmid,uint64_t & plo)24 inline uint8_t decimal_helper_div10(uint64_t& phi,
25 uint64_t& pmid,
26 uint64_t& plo) {
27 uint8_t retVal;
28 pmid += FXMATH_DECIMAL_LSHIFT32BIT(phi % 0xA);
29 phi /= 0xA;
30 plo += FXMATH_DECIMAL_LSHIFT32BIT(pmid % 0xA);
31 pmid /= 0xA;
32 retVal = plo % 0xA;
33 plo /= 0xA;
34 return retVal;
35 }
36
decimal_helper_div10_any(uint64_t nums[],uint8_t numcount)37 inline uint8_t decimal_helper_div10_any(uint64_t nums[], uint8_t numcount) {
38 uint8_t retVal = 0;
39 for (int i = numcount - 1; i > 0; i--) {
40 nums[i - 1] += FXMATH_DECIMAL_LSHIFT32BIT(nums[i] % 0xA);
41 nums[i] /= 0xA;
42 }
43 if (numcount) {
44 retVal = nums[0] % 0xA;
45 nums[0] /= 0xA;
46 }
47 return retVal;
48 }
49
decimal_helper_mul10(uint64_t & phi,uint64_t & pmid,uint64_t & plo)50 inline void decimal_helper_mul10(uint64_t& phi, uint64_t& pmid, uint64_t& plo) {
51 plo *= 0xA;
52 pmid = pmid * 0xA + FXMATH_DECIMAL_RSHIFT32BIT(plo);
53 plo = (uint32_t)plo;
54 phi = phi * 0xA + FXMATH_DECIMAL_RSHIFT32BIT(pmid);
55 pmid = (uint32_t)pmid;
56 }
57
decimal_helper_mul10_any(uint64_t nums[],uint8_t numcount)58 inline void decimal_helper_mul10_any(uint64_t nums[], uint8_t numcount) {
59 nums[0] *= 0xA;
60 for (int i = 1; i < numcount; i++) {
61 nums[i] = nums[i] * 0xA + FXMATH_DECIMAL_RSHIFT32BIT(nums[i - 1]);
62 nums[i - 1] = (uint32_t)nums[i - 1];
63 }
64 }
65
decimal_helper_normalize(uint64_t & phi,uint64_t & pmid,uint64_t & plo)66 inline void decimal_helper_normalize(uint64_t& phi,
67 uint64_t& pmid,
68 uint64_t& plo) {
69 phi += FXMATH_DECIMAL_RSHIFT32BIT(pmid);
70 pmid = (uint32_t)pmid;
71 pmid += FXMATH_DECIMAL_RSHIFT32BIT(plo);
72 plo = (uint32_t)plo;
73 phi += FXMATH_DECIMAL_RSHIFT32BIT(pmid);
74 pmid = (uint32_t)pmid;
75 }
76
decimal_helper_normalize_any(uint64_t nums[],uint8_t len)77 inline void decimal_helper_normalize_any(uint64_t nums[], uint8_t len) {
78 for (int i = len - 2; i > 0; i--) {
79 nums[i + 1] += FXMATH_DECIMAL_RSHIFT32BIT(nums[i]);
80 nums[i] = (uint32_t)nums[i];
81 }
82 for (int i = 0; i < len - 1; i++) {
83 nums[i + 1] += FXMATH_DECIMAL_RSHIFT32BIT(nums[i]);
84 nums[i] = (uint32_t)nums[i];
85 }
86 }
87
decimal_helper_raw_compare_any(uint64_t a[],uint8_t al,uint64_t b[],uint8_t bl)88 inline int8_t decimal_helper_raw_compare_any(uint64_t a[],
89 uint8_t al,
90 uint64_t b[],
91 uint8_t bl) {
92 int8_t retVal = 0;
93 for (int i = std::max(al - 1, bl - 1); i >= 0; i--) {
94 uint64_t l = (i >= al ? 0 : a[i]), r = (i >= bl ? 0 : b[i]);
95 retVal += (l > r ? 1 : (l < r ? -1 : 0));
96 if (retVal)
97 return retVal;
98 }
99 return retVal;
100 }
101
decimal_helper_dec_any(uint64_t a[],uint8_t al)102 inline void decimal_helper_dec_any(uint64_t a[], uint8_t al) {
103 for (int i = 0; i < al; i++) {
104 if (a[i]--)
105 return;
106 }
107 }
108
decimal_helper_inc_any(uint64_t a[],uint8_t al)109 inline void decimal_helper_inc_any(uint64_t a[], uint8_t al) {
110 for (int i = 0; i < al; i++) {
111 a[i]++;
112 if ((uint32_t)a[i] == a[i])
113 return;
114 a[i] = 0;
115 }
116 }
117
decimal_helper_raw_mul(uint64_t a[],uint8_t al,uint64_t b[],uint8_t bl,uint64_t c[],uint8_t cl)118 inline void decimal_helper_raw_mul(uint64_t a[],
119 uint8_t al,
120 uint64_t b[],
121 uint8_t bl,
122 uint64_t c[],
123 uint8_t cl) {
124 DCHECK(al + bl <= cl);
125 for (int i = 0; i < cl; i++)
126 c[i] = 0;
127
128 for (int i = 0; i < al; i++) {
129 for (int j = 0; j < bl; j++) {
130 uint64_t m = (uint64_t)a[i] * b[j];
131 c[i + j] += (uint32_t)m;
132 c[i + j + 1] += FXMATH_DECIMAL_RSHIFT32BIT(m);
133 }
134 }
135 for (int i = 0; i < cl - 1; i++) {
136 c[i + 1] += FXMATH_DECIMAL_RSHIFT32BIT(c[i]);
137 c[i] = (uint32_t)c[i];
138 }
139 for (int i = 0; i < cl; i++)
140 c[i] = (uint32_t)c[i];
141 }
142
decimal_helper_raw_div(uint64_t a[],uint8_t al,uint64_t b[],uint8_t bl,uint64_t c[],uint8_t cl)143 inline void decimal_helper_raw_div(uint64_t a[],
144 uint8_t al,
145 uint64_t b[],
146 uint8_t bl,
147 uint64_t c[],
148 uint8_t cl) {
149 for (int i = 0; i < cl; i++)
150 c[i] = 0;
151
152 uint64_t left[16] = {0};
153 uint64_t right[16] = {0};
154 left[0] = 0;
155 for (int i = 0; i < al; i++)
156 right[i] = a[i];
157
158 uint64_t tmp[16];
159 while (decimal_helper_raw_compare_any(left, al, right, al) <= 0) {
160 uint64_t cur[16];
161 for (int i = 0; i < al; i++)
162 cur[i] = left[i] + right[i];
163
164 for (int i = al - 1; i >= 0; i--) {
165 if (i)
166 cur[i - 1] += FXMATH_DECIMAL_LSHIFT32BIT(cur[i] % 2);
167 cur[i] /= 2;
168 }
169
170 decimal_helper_raw_mul(cur, al, b, bl, tmp, 16);
171 switch (decimal_helper_raw_compare_any(tmp, 16, a, al)) {
172 case -1:
173 for (int i = 0; i < 16; i++)
174 left[i] = cur[i];
175
176 left[0]++;
177 decimal_helper_normalize_any(left, al);
178 break;
179 case 1:
180 for (int i = 0; i < 16; i++)
181 right[i] = cur[i];
182 decimal_helper_dec_any(right, al);
183 break;
184 case 0:
185 for (int i = 0; i < std::min(al, cl); i++)
186 c[i] = cur[i];
187 return;
188 }
189 }
190 for (int i = 0; i < std::min(al, cl); i++)
191 c[i] = left[i];
192 }
193
decimal_helper_outofrange(uint64_t a[],uint8_t al,uint8_t goal)194 inline bool decimal_helper_outofrange(uint64_t a[], uint8_t al, uint8_t goal) {
195 for (int i = goal; i < al; i++) {
196 if (a[i])
197 return true;
198 }
199 return false;
200 }
201
decimal_helper_shrinkintorange(uint64_t a[],uint8_t al,uint8_t goal,uint8_t & scale)202 inline void decimal_helper_shrinkintorange(uint64_t a[],
203 uint8_t al,
204 uint8_t goal,
205 uint8_t& scale) {
206 bool bRoundUp = false;
207 while (scale != 0 && (scale > FXMATH_DECIMAL_SCALELIMIT ||
208 decimal_helper_outofrange(a, al, goal))) {
209 bRoundUp = decimal_helper_div10_any(a, al) >= 5;
210 scale--;
211 }
212 if (bRoundUp) {
213 decimal_helper_normalize_any(a, goal);
214 decimal_helper_inc_any(a, goal);
215 }
216 }
217
decimal_helper_truncate(uint64_t & phi,uint64_t & pmid,uint64_t & plo,uint8_t & scale,uint8_t minscale=0)218 inline void decimal_helper_truncate(uint64_t& phi,
219 uint64_t& pmid,
220 uint64_t& plo,
221 uint8_t& scale,
222 uint8_t minscale = 0) {
223 while (scale > minscale) {
224 uint64_t thi = phi, tmid = pmid, tlo = plo;
225 if (decimal_helper_div10(thi, tmid, tlo) != 0)
226 break;
227
228 phi = thi;
229 pmid = tmid;
230 plo = tlo;
231 scale--;
232 }
233 }
234
235 } // namespace
236
237 CFGAS_Decimal::CFGAS_Decimal() = default;
238
CFGAS_Decimal(uint64_t val)239 CFGAS_Decimal::CFGAS_Decimal(uint64_t val)
240 : m_uMid(static_cast<uint32_t>(FXMATH_DECIMAL_RSHIFT32BIT(val))),
241 m_uLo(static_cast<uint32_t>(val)) {}
242
CFGAS_Decimal(uint32_t val)243 CFGAS_Decimal::CFGAS_Decimal(uint32_t val)
244 : m_uLo(static_cast<uint32_t>(val)) {}
245
CFGAS_Decimal(uint32_t lo,uint32_t mid,uint32_t hi,bool neg,uint8_t scale)246 CFGAS_Decimal::CFGAS_Decimal(uint32_t lo,
247 uint32_t mid,
248 uint32_t hi,
249 bool neg,
250 uint8_t scale)
251 : m_uHi(hi),
252 m_uMid(mid),
253 m_uLo(lo),
254 m_bNeg(neg && IsNotZero()),
255 m_uScale(scale > FXMATH_DECIMAL_SCALELIMIT ? 0 : scale) {}
256
CFGAS_Decimal(int32_t val)257 CFGAS_Decimal::CFGAS_Decimal(int32_t val) {
258 if (val >= 0) {
259 *this = CFGAS_Decimal(static_cast<uint32_t>(val));
260 } else if (val == std::numeric_limits<int32_t>::min()) {
261 *this = CFGAS_Decimal(static_cast<uint32_t>(val));
262 SetNegate();
263 } else {
264 *this = CFGAS_Decimal(static_cast<uint32_t>(-val));
265 SetNegate();
266 }
267 }
268
CFGAS_Decimal(float val,uint8_t scale)269 CFGAS_Decimal::CFGAS_Decimal(float val, uint8_t scale) {
270 float newval = fabs(val);
271 float divisor = powf(2.0, 64.0f);
272 uint64_t bottom64 = static_cast<uint64_t>(fmodf(newval, divisor));
273 uint64_t top64 = static_cast<uint64_t>(newval / divisor);
274 uint64_t plo = bottom64 & 0xFFFFFFFF;
275 uint64_t pmid = bottom64 >> 32;
276 uint64_t phi = top64 & 0xFFFFFFFF;
277
278 newval = fmodf(newval, 1.0f);
279 for (uint8_t iter = 0; iter < scale; iter++) {
280 decimal_helper_mul10(phi, pmid, plo);
281 newval *= 10;
282 plo += static_cast<uint64_t>(newval);
283 newval = fmodf(newval, 1.0f);
284 }
285
286 plo += FXSYS_roundf(newval);
287 decimal_helper_normalize(phi, pmid, plo);
288 m_uHi = static_cast<uint32_t>(phi);
289 m_uMid = static_cast<uint32_t>(pmid);
290 m_uLo = static_cast<uint32_t>(plo);
291 m_bNeg = val < 0 && IsNotZero();
292 m_uScale = scale;
293 }
294
CFGAS_Decimal(WideStringView strObj)295 CFGAS_Decimal::CFGAS_Decimal(WideStringView strObj) {
296 const wchar_t* str = strObj.unterminated_c_str();
297 const wchar_t* strBound = str + strObj.GetLength();
298 bool pointmet = false;
299 bool negmet = false;
300 uint8_t scale = 0;
301 while (str != strBound && *str == ' ')
302 str++;
303 if (str != strBound && *str == '-') {
304 negmet = true;
305 str++;
306 } else if (str != strBound && *str == '+') {
307 str++;
308 }
309
310 while (str != strBound && (FXSYS_IsDecimalDigit(*str) || *str == '.') &&
311 scale < FXMATH_DECIMAL_SCALELIMIT) {
312 if (*str == '.') {
313 if (!pointmet)
314 pointmet = true;
315 } else {
316 m_uHi = m_uHi * 0xA + FXMATH_DECIMAL_RSHIFT32BIT((uint64_t)m_uMid * 0xA);
317 m_uMid = m_uMid * 0xA + FXMATH_DECIMAL_RSHIFT32BIT((uint64_t)m_uLo * 0xA);
318 m_uLo = m_uLo * 0xA + (*str - '0');
319 if (pointmet)
320 scale++;
321 }
322 str++;
323 }
324 m_bNeg = negmet && IsNotZero();
325 m_uScale = scale;
326 }
327
ToWideString() const328 WideString CFGAS_Decimal::ToWideString() const {
329 WideString retString;
330 WideString tmpbuf;
331 uint64_t phi = m_uHi;
332 uint64_t pmid = m_uMid;
333 uint64_t plo = m_uLo;
334 while (phi || pmid || plo)
335 tmpbuf += decimal_helper_div10(phi, pmid, plo) + '0';
336
337 uint8_t outputlen = (uint8_t)tmpbuf.GetLength();
338 uint8_t scale = m_uScale;
339 while (scale >= outputlen) {
340 tmpbuf += '0';
341 outputlen++;
342 }
343 if (m_bNeg && IsNotZero())
344 retString += '-';
345
346 for (uint8_t idx = 0; idx < outputlen; idx++) {
347 if (idx == (outputlen - scale) && scale != 0)
348 retString += '.';
349 retString += tmpbuf[outputlen - 1 - idx];
350 }
351 return retString;
352 }
353
ToFloat() const354 float CFGAS_Decimal::ToFloat() const {
355 return static_cast<float>(ToDouble());
356 }
357
ToDouble() const358 double CFGAS_Decimal::ToDouble() const {
359 double pow = (double)(1 << 16) * (1 << 16);
360 double base = static_cast<double>(m_uHi) * pow * pow +
361 static_cast<double>(m_uMid) * pow + static_cast<double>(m_uLo);
362 return (m_bNeg ? -1 : 1) * base * powf(10.0f, -m_uScale);
363 }
364
SetScale(uint8_t newscale)365 void CFGAS_Decimal::SetScale(uint8_t newscale) {
366 uint8_t oldscale = m_uScale;
367 if (oldscale == newscale)
368 return;
369
370 uint64_t phi = m_uHi;
371 uint64_t pmid = m_uMid;
372 uint64_t plo = m_uLo;
373 if (newscale > oldscale) {
374 for (uint8_t iter = 0; iter < newscale - oldscale; iter++)
375 decimal_helper_mul10(phi, pmid, plo);
376
377 m_uHi = static_cast<uint32_t>(phi);
378 m_uMid = static_cast<uint32_t>(pmid);
379 m_uLo = static_cast<uint32_t>(plo);
380 m_bNeg = m_bNeg && IsNotZero();
381 m_uScale = newscale;
382 } else {
383 uint64_t point5_hi = 0;
384 uint64_t point5_mid = 0;
385 uint64_t point5_lo = 5;
386 for (uint8_t iter = 0; iter < oldscale - newscale - 1; iter++)
387 decimal_helper_mul10(point5_hi, point5_mid, point5_lo);
388
389 phi += point5_hi;
390 pmid += point5_mid;
391 plo += point5_lo;
392 decimal_helper_normalize(phi, pmid, plo);
393 for (uint8_t iter = 0; iter < oldscale - newscale; iter++)
394 decimal_helper_div10(phi, pmid, plo);
395 }
396 m_uHi = static_cast<uint32_t>(phi);
397 m_uMid = static_cast<uint32_t>(pmid);
398 m_uLo = static_cast<uint32_t>(plo);
399 m_bNeg = m_bNeg && IsNotZero();
400 m_uScale = newscale;
401 }
402
SetNegate()403 void CFGAS_Decimal::SetNegate() {
404 if (IsNotZero())
405 m_bNeg = !m_bNeg;
406 }
407
operator *(const CFGAS_Decimal & val) const408 CFGAS_Decimal CFGAS_Decimal::operator*(const CFGAS_Decimal& val) const {
409 uint64_t a[3] = {m_uLo, m_uMid, m_uHi},
410 b[3] = {val.m_uLo, val.m_uMid, val.m_uHi};
411 uint64_t c[6];
412 decimal_helper_raw_mul(a, 3, b, 3, c, 6);
413 bool neg = m_bNeg ^ val.m_bNeg;
414 uint8_t scale = m_uScale + val.m_uScale;
415 decimal_helper_shrinkintorange(c, 6, 3, scale);
416 return CFGAS_Decimal(static_cast<uint32_t>(c[0]), static_cast<uint32_t>(c[1]),
417 static_cast<uint32_t>(c[2]), neg, scale);
418 }
419
operator /(const CFGAS_Decimal & val) const420 CFGAS_Decimal CFGAS_Decimal::operator/(const CFGAS_Decimal& val) const {
421 if (!val.IsNotZero())
422 return CFGAS_Decimal();
423
424 bool neg = m_bNeg ^ val.m_bNeg;
425 uint64_t a[7] = {m_uLo, m_uMid, m_uHi},
426 b[3] = {val.m_uLo, val.m_uMid, val.m_uHi}, c[7] = {0};
427 uint8_t scale = 0;
428 if (m_uScale < val.m_uScale) {
429 for (int i = val.m_uScale - m_uScale; i > 0; i--)
430 decimal_helper_mul10_any(a, 7);
431 } else {
432 scale = m_uScale - val.m_uScale;
433 }
434
435 uint8_t minscale = scale;
436 if (!IsNotZero())
437 return CFGAS_Decimal(0, 0, 0, false, minscale);
438
439 while (!a[6]) {
440 decimal_helper_mul10_any(a, 7);
441 scale++;
442 }
443
444 decimal_helper_div10_any(a, 7);
445 scale--;
446 decimal_helper_raw_div(a, 6, b, 3, c, 7);
447 decimal_helper_shrinkintorange(c, 6, 3, scale);
448 decimal_helper_truncate(c[2], c[1], c[0], scale, minscale);
449 return CFGAS_Decimal(static_cast<uint32_t>(c[0]), static_cast<uint32_t>(c[1]),
450 static_cast<uint32_t>(c[2]), neg, scale);
451 }
452