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1 /*
2  * Copyright © 2017  Google, Inc.
3  * Copyright © 2019  Facebook, Inc.
4  *
5  *  This is part of HarfBuzz, a text shaping library.
6  *
7  * Permission is hereby granted, without written agreement and without
8  * license or royalty fees, to use, copy, modify, and distribute this
9  * software and its documentation for any purpose, provided that the
10  * above copyright notice and the following two paragraphs appear in
11  * all copies of this software.
12  *
13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17  * DAMAGE.
18  *
19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24  *
25  * Google Author(s): Behdad Esfahbod
26  * Facebook Author(s): Behdad Esfahbod
27  */
28 
29 #ifndef HB_ALGS_HH
30 #define HB_ALGS_HH
31 
32 #include "hb.hh"
33 #include "hb-meta.hh"
34 #include "hb-null.hh"
35 #include "hb-number.hh"
36 
37 
38 /* Encodes three unsigned integers in one 64-bit number.  If the inputs have more than 21 bits,
39  * values will be truncated / overlap, and might not decode exactly. */
40 #define HB_CODEPOINT_ENCODE3(x,y,z) (((uint64_t) (x) << 42) | ((uint64_t) (y) << 21) | (uint64_t) (z))
41 #define HB_CODEPOINT_DECODE3_1(v) ((hb_codepoint_t) ((v) >> 42))
42 #define HB_CODEPOINT_DECODE3_2(v) ((hb_codepoint_t) ((v) >> 21) & 0x1FFFFFu)
43 #define HB_CODEPOINT_DECODE3_3(v) ((hb_codepoint_t) (v) & 0x1FFFFFu)
44 
45 /* Custom encoding used by hb-ucd. */
46 #define HB_CODEPOINT_ENCODE3_11_7_14(x,y,z) (((uint32_t) ((x) & 0x07FFu) << 21) | (((uint32_t) (y) & 0x007Fu) << 14) | (uint32_t) ((z) & 0x3FFFu))
47 #define HB_CODEPOINT_DECODE3_11_7_14_1(v) ((hb_codepoint_t) ((v) >> 21))
48 #define HB_CODEPOINT_DECODE3_11_7_14_2(v) ((hb_codepoint_t) (((v) >> 14) & 0x007Fu) | 0x0300)
49 #define HB_CODEPOINT_DECODE3_11_7_14_3(v) ((hb_codepoint_t) (v) & 0x3FFFu)
50 
51 struct
52 {
53   /* Note.  This is dangerous in that if it's passed an rvalue, it returns rvalue-reference. */
54   template <typename T> constexpr auto
55   operator () (T&& v) const HB_AUTO_RETURN ( hb_forward<T> (v) )
56 }
57 HB_FUNCOBJ (hb_identity);
58 struct
59 {
60   /* Like identity(), but only retains lvalue-references.  Rvalues are returned as rvalues. */
61   template <typename T> constexpr T&
operator ()__anon2f73037a020862   operator () (T& v) const { return v; }
63 
64   template <typename T> constexpr hb_remove_reference<T>
operator ()__anon2f73037a020865   operator () (T&& v) const { return v; }
66 }
67 HB_FUNCOBJ (hb_lidentity);
68 struct
69 {
70   /* Like identity(), but always returns rvalue. */
71   template <typename T> constexpr hb_remove_reference<T>
operator ()__anon2f73037a030872   operator () (T&& v) const { return v; }
73 }
74 HB_FUNCOBJ (hb_ridentity);
75 
76 struct
77 {
78   template <typename T> constexpr bool
operator ()__anon2f73037a040879   operator () (T&& v) const { return bool (hb_forward<T> (v)); }
80 }
81 HB_FUNCOBJ (hb_bool);
82 
83 struct
84 {
85   private:
86 
87   template <typename T> constexpr auto
88   impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, hb_deref (v).hash ())
89 
90   template <typename T,
91 	    hb_enable_if (hb_is_integral (T))> constexpr auto
92   impl (const T& v, hb_priority<0>) const HB_AUTO_RETURN
93   (
94     /* Knuth's multiplicative method: */
95     (uint32_t) v * 2654435761u
96   )
97 
98   public:
99 
100   template <typename T> constexpr auto
101   operator () (const T& v) const HB_RETURN (uint32_t, impl (v, hb_prioritize))
102 }
103 HB_FUNCOBJ (hb_hash);
104 
105 
106 struct
107 {
108   private:
109 
110   /* Pointer-to-member-function. */
111   template <typename Appl, typename T, typename ...Ts> auto
112   impl (Appl&& a, hb_priority<2>, T &&v, Ts&&... ds) const HB_AUTO_RETURN
113   ((hb_deref (hb_forward<T> (v)).*hb_forward<Appl> (a)) (hb_forward<Ts> (ds)...))
114 
115   /* Pointer-to-member. */
116   template <typename Appl, typename T> auto
117   impl (Appl&& a, hb_priority<1>, T &&v) const HB_AUTO_RETURN
118   ((hb_deref (hb_forward<T> (v))).*hb_forward<Appl> (a))
119 
120   /* Operator(). */
121   template <typename Appl, typename ...Ts> auto
122   impl (Appl&& a, hb_priority<0>, Ts&&... ds) const HB_AUTO_RETURN
123   (hb_deref (hb_forward<Appl> (a)) (hb_forward<Ts> (ds)...))
124 
125   public:
126 
127   template <typename Appl, typename ...Ts> auto
128   operator () (Appl&& a, Ts&&... ds) const HB_AUTO_RETURN
129   (
130     impl (hb_forward<Appl> (a),
131 	  hb_prioritize,
132 	  hb_forward<Ts> (ds)...)
133   )
134 }
135 HB_FUNCOBJ (hb_invoke);
136 
137 template <unsigned Pos, typename Appl, typename V>
138 struct hb_partial_t
139 {
hb_partial_thb_partial_t140   hb_partial_t (Appl a, V v) : a (a), v (v) {}
141 
142   static_assert (Pos > 0, "");
143 
144   template <typename ...Ts,
145 	    unsigned P = Pos,
146 	    hb_enable_if (P == 1)> auto
operator ()hb_partial_t147   operator () (Ts&& ...ds) -> decltype (hb_invoke (hb_declval (Appl),
148 						   hb_declval (V),
149 						   hb_declval (Ts)...))
150   {
151     return hb_invoke (hb_forward<Appl> (a),
152 		      hb_forward<V> (v),
153 		      hb_forward<Ts> (ds)...);
154   }
155   template <typename T0, typename ...Ts,
156 	    unsigned P = Pos,
157 	    hb_enable_if (P == 2)> auto
operator ()hb_partial_t158   operator () (T0&& d0, Ts&& ...ds) -> decltype (hb_invoke (hb_declval (Appl),
159 							    hb_declval (T0),
160 							    hb_declval (V),
161 							    hb_declval (Ts)...))
162   {
163     return hb_invoke (hb_forward<Appl> (a),
164 		      hb_forward<T0> (d0),
165 		      hb_forward<V> (v),
166 		      hb_forward<Ts> (ds)...);
167   }
168 
169   private:
170   hb_reference_wrapper<Appl> a;
171   V v;
172 };
173 template <unsigned Pos=1, typename Appl, typename V>
174 auto hb_partial (Appl&& a, V&& v) HB_AUTO_RETURN
175 (( hb_partial_t<Pos, Appl, V> (a, v) ))
176 
177 /* The following, HB_PARTIALIZE, macro uses a particular corner-case
178  * of C++11 that is not particularly well-supported by all compilers.
179  * What's happening is that it's using "this" in a trailing return-type
180  * via decltype().  Broken compilers deduce the type of "this" pointer
181  * in that context differently from what it resolves to in the body
182  * of the function.
183  *
184  * One probable cause of this is that at the time of trailing return
185  * type declaration, "this" points to an incomplete type, whereas in
186  * the function body the type is complete.  That doesn't justify the
187  * error in any way, but is probably what's happening.
188  *
189  * In the case of MSVC, we get around this by using C++14 "decltype(auto)"
190  * which deduces the type from the actual return statement.  For gcc 4.8
191  * we use "+this" instead of "this" which produces an rvalue that seems
192  * to be deduced as the same type with this particular compiler, and seem
193  * to be fine as default code path as well.
194  */
195 #ifdef _MSC_VER
196 /* https://github.com/harfbuzz/harfbuzz/issues/1730 */ \
197 #define HB_PARTIALIZE(Pos) \
198   template <typename _T> \
199   decltype(auto) operator () (_T&& _v) const \
200   { return hb_partial<Pos> (this, hb_forward<_T> (_v)); } \
201   static_assert (true, "")
202 #else
203 /* https://github.com/harfbuzz/harfbuzz/issues/1724 */
204 #define HB_PARTIALIZE(Pos) \
205   template <typename _T> \
206   auto operator () (_T&& _v) const HB_AUTO_RETURN \
207   (hb_partial<Pos> (+this, hb_forward<_T> (_v))) \
208   static_assert (true, "")
209 #endif
210 
211 
212 struct
213 {
214   private:
215 
216   template <typename Pred, typename Val> auto
217   impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN
218   (hb_deref (hb_forward<Pred> (p)).has (hb_forward<Val> (v)))
219 
220   template <typename Pred, typename Val> auto
221   impl (Pred&& p, Val &&v, hb_priority<0>) const HB_AUTO_RETURN
222   (
223     hb_invoke (hb_forward<Pred> (p),
224 	       hb_forward<Val> (v))
225   )
226 
227   public:
228 
229   template <typename Pred, typename Val> auto
230   operator () (Pred&& p, Val &&v) const HB_RETURN (bool,
231     impl (hb_forward<Pred> (p),
232 	  hb_forward<Val> (v),
233 	  hb_prioritize)
234   )
235 }
236 HB_FUNCOBJ (hb_has);
237 
238 struct
239 {
240   private:
241 
242   template <typename Pred, typename Val> auto
243   impl (Pred&& p, Val &&v, hb_priority<1>) const HB_AUTO_RETURN
244   (
245     hb_has (hb_forward<Pred> (p),
246 	    hb_forward<Val> (v))
247   )
248 
249   template <typename Pred, typename Val> auto
250   impl (Pred&& p, Val &&v, hb_priority<0>) const HB_AUTO_RETURN
251   (
252     hb_forward<Pred> (p) == hb_forward<Val> (v)
253   )
254 
255   public:
256 
257   template <typename Pred, typename Val> auto
258   operator () (Pred&& p, Val &&v) const HB_RETURN (bool,
259     impl (hb_forward<Pred> (p),
260 	  hb_forward<Val> (v),
261 	  hb_prioritize)
262   )
263 }
264 HB_FUNCOBJ (hb_match);
265 
266 struct
267 {
268   private:
269 
270   template <typename Proj, typename Val> auto
271   impl (Proj&& f, Val &&v, hb_priority<2>) const HB_AUTO_RETURN
272   (hb_deref (hb_forward<Proj> (f)).get (hb_forward<Val> (v)))
273 
274   template <typename Proj, typename Val> auto
275   impl (Proj&& f, Val &&v, hb_priority<1>) const HB_AUTO_RETURN
276   (
277     hb_invoke (hb_forward<Proj> (f),
278 	       hb_forward<Val> (v))
279   )
280 
281   template <typename Proj, typename Val> auto
282   impl (Proj&& f, Val &&v, hb_priority<0>) const HB_AUTO_RETURN
283   (
284     hb_forward<Proj> (f)[hb_forward<Val> (v)]
285   )
286 
287   public:
288 
289   template <typename Proj, typename Val> auto
290   operator () (Proj&& f, Val &&v) const HB_AUTO_RETURN
291   (
292     impl (hb_forward<Proj> (f),
293 	  hb_forward<Val> (v),
294 	  hb_prioritize)
295   )
296 }
297 HB_FUNCOBJ (hb_get);
298 
299 
300 template <typename T1, typename T2>
301 struct hb_pair_t
302 {
303   typedef T1 first_t;
304   typedef T2 second_t;
305   typedef hb_pair_t<T1, T2> pair_t;
306 
hb_pair_thb_pair_t307   hb_pair_t (T1 a, T2 b) : first (a), second (b) {}
308 
309   template <typename Q1, typename Q2,
310 	    hb_enable_if (hb_is_convertible (T1, Q1) &&
311 			  hb_is_convertible (T2, T2))>
operator hb_pair_t<Q1,Q2>hb_pair_t312   operator hb_pair_t<Q1, Q2> () { return hb_pair_t<Q1, Q2> (first, second); }
313 
reversehb_pair_t314   hb_pair_t<T1, T2> reverse () const
315   { return hb_pair_t<T1, T2> (second, first); }
316 
operator ==hb_pair_t317   bool operator == (const pair_t& o) const { return first == o.first && second == o.second; }
operator !=hb_pair_t318   bool operator != (const pair_t& o) const { return !(*this == o); }
operator <hb_pair_t319   bool operator < (const pair_t& o) const { return first < o.first || (first == o.first && second < o.second); }
operator >=hb_pair_t320   bool operator >= (const pair_t& o) const { return !(*this < o); }
operator >hb_pair_t321   bool operator > (const pair_t& o) const { return first > o.first || (first == o.first && second > o.second); }
operator <=hb_pair_t322   bool operator <= (const pair_t& o) const { return !(*this > o); }
323 
324   T1 first;
325   T2 second;
326 };
327 #define hb_pair_t(T1,T2) hb_pair_t<T1, T2>
328 template <typename T1, typename T2> static inline hb_pair_t<T1, T2>
hb_pair(T1 && a,T2 && b)329 hb_pair (T1&& a, T2&& b) { return hb_pair_t<T1, T2> (a, b); }
330 
331 struct
332 {
333   template <typename Pair> constexpr typename Pair::first_t
operator ()__anon2f73037a0a08334   operator () (const Pair& pair) const { return pair.first; }
335 }
336 HB_FUNCOBJ (hb_first);
337 
338 struct
339 {
340   template <typename Pair> constexpr typename Pair::second_t
operator ()__anon2f73037a0b08341   operator () (const Pair& pair) const { return pair.second; }
342 }
343 HB_FUNCOBJ (hb_second);
344 
345 /* Note.  In min/max impl, we can use hb_type_identity<T> for second argument.
346  * However, that would silently convert between different-signedness integers.
347  * Instead we accept two different types, such that compiler can err if
348  * comparing integers of different signedness. */
349 struct
350 {
351   template <typename T, typename T2> constexpr auto
352   operator () (T&& a, T2&& b) const HB_AUTO_RETURN
353   (hb_forward<T> (a) <= hb_forward<T2> (b) ? hb_forward<T> (a) : hb_forward<T2> (b))
354 }
355 HB_FUNCOBJ (hb_min);
356 struct
357 {
358   template <typename T, typename T2> constexpr auto
359   operator () (T&& a, T2&& b) const HB_AUTO_RETURN
360   (hb_forward<T> (a) >= hb_forward<T2> (b) ? hb_forward<T> (a) : hb_forward<T2> (b))
361 }
362 HB_FUNCOBJ (hb_max);
363 
364 
365 /*
366  * Bithacks.
367  */
368 
369 /* Return the number of 1 bits in v. */
370 template <typename T>
371 static inline HB_CONST_FUNC unsigned int
hb_popcount(T v)372 hb_popcount (T v)
373 {
374 #if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
375   if (sizeof (T) <= sizeof (unsigned int))
376     return __builtin_popcount (v);
377 
378   if (sizeof (T) <= sizeof (unsigned long))
379     return __builtin_popcountl (v);
380 
381   if (sizeof (T) <= sizeof (unsigned long long))
382     return __builtin_popcountll (v);
383 #endif
384 
385   if (sizeof (T) <= 4)
386   {
387     /* "HACKMEM 169" */
388     uint32_t y;
389     y = (v >> 1) &033333333333;
390     y = v - y - ((y >>1) & 033333333333);
391     return (((y + (y >> 3)) & 030707070707) % 077);
392   }
393 
394   if (sizeof (T) == 8)
395   {
396     unsigned int shift = 32;
397     return hb_popcount<uint32_t> ((uint32_t) v) + hb_popcount ((uint32_t) (v >> shift));
398   }
399 
400   if (sizeof (T) == 16)
401   {
402     unsigned int shift = 64;
403     return hb_popcount<uint64_t> ((uint64_t) v) + hb_popcount ((uint64_t) (v >> shift));
404   }
405 
406   assert (0);
407   return 0; /* Shut up stupid compiler. */
408 }
409 
410 /* Returns the number of bits needed to store number */
411 template <typename T>
412 static inline HB_CONST_FUNC unsigned int
hb_bit_storage(T v)413 hb_bit_storage (T v)
414 {
415   if (unlikely (!v)) return 0;
416 
417 #if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
418   if (sizeof (T) <= sizeof (unsigned int))
419     return sizeof (unsigned int) * 8 - __builtin_clz (v);
420 
421   if (sizeof (T) <= sizeof (unsigned long))
422     return sizeof (unsigned long) * 8 - __builtin_clzl (v);
423 
424   if (sizeof (T) <= sizeof (unsigned long long))
425     return sizeof (unsigned long long) * 8 - __builtin_clzll (v);
426 #endif
427 
428 #if (defined(_MSC_VER) && _MSC_VER >= 1500) || (defined(__MINGW32__) && (__GNUC__ < 4))
429   if (sizeof (T) <= sizeof (unsigned int))
430   {
431     unsigned long where;
432     _BitScanReverse (&where, v);
433     return 1 + where;
434   }
435 # if defined(_WIN64)
436   if (sizeof (T) <= 8)
437   {
438     unsigned long where;
439     _BitScanReverse64 (&where, v);
440     return 1 + where;
441   }
442 # endif
443 #endif
444 
445   if (sizeof (T) <= 4)
446   {
447     /* "bithacks" */
448     const unsigned int b[] = {0x2, 0xC, 0xF0, 0xFF00, 0xFFFF0000};
449     const unsigned int S[] = {1, 2, 4, 8, 16};
450     unsigned int r = 0;
451     for (int i = 4; i >= 0; i--)
452       if (v & b[i])
453       {
454 	v >>= S[i];
455 	r |= S[i];
456       }
457     return r + 1;
458   }
459   if (sizeof (T) <= 8)
460   {
461     /* "bithacks" */
462     const uint64_t b[] = {0x2ULL, 0xCULL, 0xF0ULL, 0xFF00ULL, 0xFFFF0000ULL, 0xFFFFFFFF00000000ULL};
463     const unsigned int S[] = {1, 2, 4, 8, 16, 32};
464     unsigned int r = 0;
465     for (int i = 5; i >= 0; i--)
466       if (v & b[i])
467       {
468 	v >>= S[i];
469 	r |= S[i];
470       }
471     return r + 1;
472   }
473   if (sizeof (T) == 16)
474   {
475     unsigned int shift = 64;
476     return (v >> shift) ? hb_bit_storage<uint64_t> ((uint64_t) (v >> shift)) + shift :
477 			  hb_bit_storage<uint64_t> ((uint64_t) v);
478   }
479 
480   assert (0);
481   return 0; /* Shut up stupid compiler. */
482 }
483 
484 /* Returns the number of zero bits in the least significant side of v */
485 template <typename T>
486 static inline HB_CONST_FUNC unsigned int
hb_ctz(T v)487 hb_ctz (T v)
488 {
489   if (unlikely (!v)) return 0;
490 
491 #if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__)
492   if (sizeof (T) <= sizeof (unsigned int))
493     return __builtin_ctz (v);
494 
495   if (sizeof (T) <= sizeof (unsigned long))
496     return __builtin_ctzl (v);
497 
498   if (sizeof (T) <= sizeof (unsigned long long))
499     return __builtin_ctzll (v);
500 #endif
501 
502 #if (defined(_MSC_VER) && _MSC_VER >= 1500) || (defined(__MINGW32__) && (__GNUC__ < 4))
503   if (sizeof (T) <= sizeof (unsigned int))
504   {
505     unsigned long where;
506     _BitScanForward (&where, v);
507     return where;
508   }
509 # if defined(_WIN64)
510   if (sizeof (T) <= 8)
511   {
512     unsigned long where;
513     _BitScanForward64 (&where, v);
514     return where;
515   }
516 # endif
517 #endif
518 
519   if (sizeof (T) <= 4)
520   {
521     /* "bithacks" */
522     unsigned int c = 32;
523     v &= - (int32_t) v;
524     if (v) c--;
525     if (v & 0x0000FFFF) c -= 16;
526     if (v & 0x00FF00FF) c -= 8;
527     if (v & 0x0F0F0F0F) c -= 4;
528     if (v & 0x33333333) c -= 2;
529     if (v & 0x55555555) c -= 1;
530     return c;
531   }
532   if (sizeof (T) <= 8)
533   {
534     /* "bithacks" */
535     unsigned int c = 64;
536     v &= - (int64_t) (v);
537     if (v) c--;
538     if (v & 0x00000000FFFFFFFFULL) c -= 32;
539     if (v & 0x0000FFFF0000FFFFULL) c -= 16;
540     if (v & 0x00FF00FF00FF00FFULL) c -= 8;
541     if (v & 0x0F0F0F0F0F0F0F0FULL) c -= 4;
542     if (v & 0x3333333333333333ULL) c -= 2;
543     if (v & 0x5555555555555555ULL) c -= 1;
544     return c;
545   }
546   if (sizeof (T) == 16)
547   {
548     unsigned int shift = 64;
549     return (uint64_t) v ? hb_bit_storage<uint64_t> ((uint64_t) v) :
550 			  hb_bit_storage<uint64_t> ((uint64_t) (v >> shift)) + shift;
551   }
552 
553   assert (0);
554   return 0; /* Shut up stupid compiler. */
555 }
556 
557 
558 /*
559  * Tiny stuff.
560  */
561 
562 /* ASCII tag/character handling */
ISALPHA(unsigned char c)563 static inline bool ISALPHA (unsigned char c)
564 { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); }
ISALNUM(unsigned char c)565 static inline bool ISALNUM (unsigned char c)
566 { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'); }
ISSPACE(unsigned char c)567 static inline bool ISSPACE (unsigned char c)
568 { return c == ' ' || c =='\f'|| c =='\n'|| c =='\r'|| c =='\t'|| c =='\v'; }
TOUPPER(unsigned char c)569 static inline unsigned char TOUPPER (unsigned char c)
570 { return (c >= 'a' && c <= 'z') ? c - 'a' + 'A' : c; }
TOLOWER(unsigned char c)571 static inline unsigned char TOLOWER (unsigned char c)
572 { return (c >= 'A' && c <= 'Z') ? c - 'A' + 'a' : c; }
573 
DIV_CEIL(const unsigned int a,unsigned int b)574 static inline unsigned int DIV_CEIL (const unsigned int a, unsigned int b)
575 { return (a + (b - 1)) / b; }
576 
577 
578 #undef  ARRAY_LENGTH
579 template <typename Type, unsigned int n>
ARRAY_LENGTH(const Type (&)[n])580 static inline unsigned int ARRAY_LENGTH (const Type (&)[n]) { return n; }
581 /* A const version, but does not detect erratically being called on pointers. */
582 #define ARRAY_LENGTH_CONST(__array) ((signed int) (sizeof (__array) / sizeof (__array[0])))
583 
584 
585 static inline int
hb_memcmp(const void * a,const void * b,unsigned int len)586 hb_memcmp (const void *a, const void *b, unsigned int len)
587 {
588   /* It's illegal to pass NULL to memcmp(), even if len is zero.
589    * So, wrap it.
590    * https://sourceware.org/bugzilla/show_bug.cgi?id=23878 */
591   if (unlikely (!len)) return 0;
592   return memcmp (a, b, len);
593 }
594 
595 static inline void *
hb_memset(void * s,int c,unsigned int n)596 hb_memset (void *s, int c, unsigned int n)
597 {
598   /* It's illegal to pass NULL to memset(), even if n is zero. */
599   if (unlikely (!n)) return 0;
600   return memset (s, c, n);
601 }
602 
603 static inline bool
hb_unsigned_mul_overflows(unsigned int count,unsigned int size)604 hb_unsigned_mul_overflows (unsigned int count, unsigned int size)
605 {
606   return (size > 0) && (count >= ((unsigned int) -1) / size);
607 }
608 
609 static inline unsigned int
hb_ceil_to_4(unsigned int v)610 hb_ceil_to_4 (unsigned int v)
611 {
612   return ((v - 1) | 3) + 1;
613 }
614 
615 template <typename T> static inline bool
hb_in_range(T u,T lo,T hi)616 hb_in_range (T u, T lo, T hi)
617 {
618   static_assert (!hb_is_signed<T>::value, "");
619 
620   /* The casts below are important as if T is smaller than int,
621    * the subtract results will become a signed int! */
622   return (T)(u - lo) <= (T)(hi - lo);
623 }
624 template <typename T> static inline bool
hb_in_ranges(T u,T lo1,T hi1,T lo2,T hi2)625 hb_in_ranges (T u, T lo1, T hi1, T lo2, T hi2)
626 {
627   return hb_in_range (u, lo1, hi1) || hb_in_range (u, lo2, hi2);
628 }
629 template <typename T> static inline bool
hb_in_ranges(T u,T lo1,T hi1,T lo2,T hi2,T lo3,T hi3)630 hb_in_ranges (T u, T lo1, T hi1, T lo2, T hi2, T lo3, T hi3)
631 {
632   return hb_in_range (u, lo1, hi1) || hb_in_range (u, lo2, hi2) || hb_in_range (u, lo3, hi3);
633 }
634 
635 
636 /*
637  * Sort and search.
638  */
639 template <typename ...Ts>
640 static inline void *
hb_bsearch(const void * key,const void * base,size_t nmemb,size_t size,int (* compar)(const void * _key,const void * _item,Ts..._ds),Ts...ds)641 hb_bsearch (const void *key, const void *base,
642 	    size_t nmemb, size_t size,
643 	    int (*compar)(const void *_key, const void *_item, Ts... _ds),
644 	    Ts... ds)
645 {
646   int min = 0, max = (int) nmemb - 1;
647   while (min <= max)
648   {
649     int mid = ((unsigned int) min + (unsigned int) max) / 2;
650     const void *p = (const void *) (((const char *) base) + (mid * size));
651     int c = compar (key, p, ds...);
652     if (c < 0)
653       max = mid - 1;
654     else if (c > 0)
655       min = mid + 1;
656     else
657       return (void *) p;
658   }
659   return nullptr;
660 }
661 
662 
663 /* From https://github.com/noporpoise/sort_r
664    Feb 5, 2019 (c8c65c1e)
665    Modified to support optional argument using templates */
666 
667 /* Isaac Turner 29 April 2014 Public Domain */
668 
669 /*
670 hb_qsort function to be exported.
671 Parameters:
672   base is the array to be sorted
673   nel is the number of elements in the array
674   width is the size in bytes of each element of the array
675   compar is the comparison function
676   arg (optional) is a pointer to be passed to the comparison function
677 
678 void hb_qsort(void *base, size_t nel, size_t width,
679               int (*compar)(const void *_a, const void *_b, [void *_arg]),
680               [void *arg]);
681 */
682 
683 #define SORT_R_SWAP(a,b,tmp) ((tmp) = (a), (a) = (b), (b) = (tmp))
684 
685 /* swap a and b */
686 /* a and b must not be equal! */
sort_r_swap(char * __restrict a,char * __restrict b,size_t w)687 static inline void sort_r_swap(char *__restrict a, char *__restrict b,
688                                size_t w)
689 {
690   char tmp, *end = a+w;
691   for(; a < end; a++, b++) { SORT_R_SWAP(*a, *b, tmp); }
692 }
693 
694 /* swap a, b iff a>b */
695 /* a and b must not be equal! */
696 /* __restrict is same as restrict but better support on old machines */
697 template <typename ...Ts>
sort_r_cmpswap(char * __restrict a,char * __restrict b,size_t w,int (* compar)(const void * _a,const void * _b,Ts..._ds),Ts...ds)698 static inline int sort_r_cmpswap(char *__restrict a,
699                                  char *__restrict b, size_t w,
700                                  int (*compar)(const void *_a,
701                                                const void *_b,
702                                                Ts... _ds),
703                                  Ts... ds)
704 {
705   if(compar(a, b, ds...) > 0) {
706     sort_r_swap(a, b, w);
707     return 1;
708   }
709   return 0;
710 }
711 
712 /*
713 Swap consecutive blocks of bytes of size na and nb starting at memory addr ptr,
714 with the smallest swap so that the blocks are in the opposite order. Blocks may
715 be internally re-ordered e.g.
716   12345ab  ->   ab34512
717   123abc   ->   abc123
718   12abcde  ->   deabc12
719 */
sort_r_swap_blocks(char * ptr,size_t na,size_t nb)720 static inline void sort_r_swap_blocks(char *ptr, size_t na, size_t nb)
721 {
722   if(na > 0 && nb > 0) {
723     if(na > nb) { sort_r_swap(ptr, ptr+na, nb); }
724     else { sort_r_swap(ptr, ptr+nb, na); }
725   }
726 }
727 
728 /* Implement recursive quicksort ourselves */
729 /* Note: quicksort is not stable, equivalent values may be swapped */
730 template <typename ...Ts>
sort_r_simple(void * base,size_t nel,size_t w,int (* compar)(const void * _a,const void * _b,Ts..._ds),Ts...ds)731 static inline void sort_r_simple(void *base, size_t nel, size_t w,
732                                  int (*compar)(const void *_a,
733                                                const void *_b,
734                                                Ts... _ds),
735                                  Ts... ds)
736 {
737   char *b = (char *)base, *end = b + nel*w;
738 
739   /* for(size_t i=0; i<nel; i++) {printf("%4i", *(int*)(b + i*sizeof(int)));}
740   printf("\n"); */
741 
742   if(nel < 10) {
743     /* Insertion sort for arbitrarily small inputs */
744     char *pi, *pj;
745     for(pi = b+w; pi < end; pi += w) {
746       for(pj = pi; pj > b && sort_r_cmpswap(pj-w,pj,w,compar,ds...); pj -= w) {}
747     }
748   }
749   else
750   {
751     /* nel > 9; Quicksort */
752 
753     int cmp;
754     char *pl, *ple, *pr, *pre, *pivot;
755     char *last = b+w*(nel-1), *tmp;
756 
757     /*
758     Use median of second, middle and second-last items as pivot.
759     First and last may have been swapped with pivot and therefore be extreme
760     */
761     char *l[3];
762     l[0] = b + w;
763     l[1] = b+w*(nel/2);
764     l[2] = last - w;
765 
766     /* printf("pivots: %i, %i, %i\n", *(int*)l[0], *(int*)l[1], *(int*)l[2]); */
767 
768     if(compar(l[0],l[1],ds...) > 0) { SORT_R_SWAP(l[0], l[1], tmp); }
769     if(compar(l[1],l[2],ds...) > 0) {
770       SORT_R_SWAP(l[1], l[2], tmp);
771       if(compar(l[0],l[1],ds...) > 0) { SORT_R_SWAP(l[0], l[1], tmp); }
772     }
773 
774     /* swap mid value (l[1]), and last element to put pivot as last element */
775     if(l[1] != last) { sort_r_swap(l[1], last, w); }
776 
777     /*
778     pl is the next item on the left to be compared to the pivot
779     pr is the last item on the right that was compared to the pivot
780     ple is the left position to put the next item that equals the pivot
781     ple is the last right position where we put an item that equals the pivot
782                                            v- end (beyond the array)
783       EEEEEELLLLLLLLuuuuuuuuGGGGGGGEEEEEEEE.
784       ^- b  ^- ple  ^- pl   ^- pr  ^- pre ^- last (where the pivot is)
785     Pivot comparison key:
786       E = equal, L = less than, u = unknown, G = greater than, E = equal
787     */
788     pivot = last;
789     ple = pl = b;
790     pre = pr = last;
791 
792     /*
793     Strategy:
794     Loop into the list from the left and right at the same time to find:
795     - an item on the left that is greater than the pivot
796     - an item on the right that is less than the pivot
797     Once found, they are swapped and the loop continues.
798     Meanwhile items that are equal to the pivot are moved to the edges of the
799     array.
800     */
801     while(pl < pr) {
802       /* Move left hand items which are equal to the pivot to the far left.
803          break when we find an item that is greater than the pivot */
804       for(; pl < pr; pl += w) {
805         cmp = compar(pl, pivot, ds...);
806         if(cmp > 0) { break; }
807         else if(cmp == 0) {
808           if(ple < pl) { sort_r_swap(ple, pl, w); }
809           ple += w;
810         }
811       }
812       /* break if last batch of left hand items were equal to pivot */
813       if(pl >= pr) { break; }
814       /* Move right hand items which are equal to the pivot to the far right.
815          break when we find an item that is less than the pivot */
816       for(; pl < pr; ) {
817         pr -= w; /* Move right pointer onto an unprocessed item */
818         cmp = compar(pr, pivot, ds...);
819         if(cmp == 0) {
820           pre -= w;
821           if(pr < pre) { sort_r_swap(pr, pre, w); }
822         }
823         else if(cmp < 0) {
824           if(pl < pr) { sort_r_swap(pl, pr, w); }
825           pl += w;
826           break;
827         }
828       }
829     }
830 
831     pl = pr; /* pr may have gone below pl */
832 
833     /*
834     Now we need to go from: EEELLLGGGGEEEE
835                         to: LLLEEEEEEEGGGG
836     Pivot comparison key:
837       E = equal, L = less than, u = unknown, G = greater than, E = equal
838     */
839     sort_r_swap_blocks(b, ple-b, pl-ple);
840     sort_r_swap_blocks(pr, pre-pr, end-pre);
841 
842     /*for(size_t i=0; i<nel; i++) {printf("%4i", *(int*)(b + i*sizeof(int)));}
843     printf("\n");*/
844 
845     sort_r_simple(b, (pl-ple)/w, w, compar, ds...);
846     sort_r_simple(end-(pre-pr), (pre-pr)/w, w, compar, ds...);
847   }
848 }
849 
850 static inline void
hb_qsort(void * base,size_t nel,size_t width,int (* compar)(const void * _a,const void * _b))851 hb_qsort (void *base, size_t nel, size_t width,
852 	  int (*compar)(const void *_a, const void *_b))
853 {
854 #if defined(__OPTIMIZE_SIZE__) && !defined(HB_USE_INTERNAL_QSORT)
855   qsort (base, nel, width, compar);
856 #else
857   sort_r_simple (base, nel, width, compar);
858 #endif
859 }
860 
861 static inline void
hb_qsort(void * base,size_t nel,size_t width,int (* compar)(const void * _a,const void * _b,void * _arg),void * arg)862 hb_qsort (void *base, size_t nel, size_t width,
863 	  int (*compar)(const void *_a, const void *_b, void *_arg),
864 	  void *arg)
865 {
866 #ifdef HAVE_GNU_QSORT_R
867   qsort_r (base, nel, width, compar, arg);
868 #else
869   sort_r_simple (base, nel, width, compar, arg);
870 #endif
871 }
872 
873 
874 template <typename T, typename T2, typename T3> static inline void
hb_stable_sort(T * array,unsigned int len,int (* compar)(const T2 *,const T2 *),T3 * array2)875 hb_stable_sort (T *array, unsigned int len, int(*compar)(const T2 *, const T2 *), T3 *array2)
876 {
877   for (unsigned int i = 1; i < len; i++)
878   {
879     unsigned int j = i;
880     while (j && compar (&array[j - 1], &array[i]) > 0)
881       j--;
882     if (i == j)
883       continue;
884     /* Move item i to occupy place for item j, shift what's in between. */
885     {
886       T t = array[i];
887       memmove (&array[j + 1], &array[j], (i - j) * sizeof (T));
888       array[j] = t;
889     }
890     if (array2)
891     {
892       T3 t = array2[i];
893       memmove (&array2[j + 1], &array2[j], (i - j) * sizeof (T3));
894       array2[j] = t;
895     }
896   }
897 }
898 
899 template <typename T> static inline void
hb_stable_sort(T * array,unsigned int len,int (* compar)(const T *,const T *))900 hb_stable_sort (T *array, unsigned int len, int(*compar)(const T *, const T *))
901 {
902   hb_stable_sort (array, len, compar, (int *) nullptr);
903 }
904 
905 static inline hb_bool_t
hb_codepoint_parse(const char * s,unsigned int len,int base,hb_codepoint_t * out)906 hb_codepoint_parse (const char *s, unsigned int len, int base, hb_codepoint_t *out)
907 {
908   unsigned int v;
909   const char *p = s;
910   const char *end = p + len;
911   if (unlikely (!hb_parse_uint (&p, end, &v, true/* whole buffer */, base)))
912     return false;
913 
914   *out = v;
915   return true;
916 }
917 
918 
919 /* Operators. */
920 
921 struct hb_bitwise_and
922 { HB_PARTIALIZE(2);
923   static constexpr bool passthru_left = false;
924   static constexpr bool passthru_right = false;
925   template <typename T> constexpr auto
926   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a & b)
927 }
928 HB_FUNCOBJ (hb_bitwise_and);
929 struct hb_bitwise_or
930 { HB_PARTIALIZE(2);
931   static constexpr bool passthru_left = true;
932   static constexpr bool passthru_right = true;
933   template <typename T> constexpr auto
934   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a | b)
935 }
936 HB_FUNCOBJ (hb_bitwise_or);
937 struct hb_bitwise_xor
938 { HB_PARTIALIZE(2);
939   static constexpr bool passthru_left = true;
940   static constexpr bool passthru_right = true;
941   template <typename T> constexpr auto
942   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a ^ b)
943 }
944 HB_FUNCOBJ (hb_bitwise_xor);
945 struct hb_bitwise_sub
946 { HB_PARTIALIZE(2);
947   static constexpr bool passthru_left = true;
948   static constexpr bool passthru_right = false;
949   template <typename T> constexpr auto
950   operator () (const T &a, const T &b) const HB_AUTO_RETURN (a & ~b)
951 }
952 HB_FUNCOBJ (hb_bitwise_sub);
953 struct
954 {
955   template <typename T> constexpr auto
956   operator () (const T &a) const HB_AUTO_RETURN (~a)
957 }
958 HB_FUNCOBJ (hb_bitwise_neg);
959 
960 struct
961 { HB_PARTIALIZE(2);
962   template <typename T, typename T2> constexpr auto
963   operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a + b)
964 }
965 HB_FUNCOBJ (hb_add);
966 struct
967 { HB_PARTIALIZE(2);
968   template <typename T, typename T2> constexpr auto
969   operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a - b)
970 }
971 HB_FUNCOBJ (hb_sub);
972 struct
973 { HB_PARTIALIZE(2);
974   template <typename T, typename T2> constexpr auto
975   operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a * b)
976 }
977 HB_FUNCOBJ (hb_mul);
978 struct
979 { HB_PARTIALIZE(2);
980   template <typename T, typename T2> constexpr auto
981   operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a / b)
982 }
983 HB_FUNCOBJ (hb_div);
984 struct
985 { HB_PARTIALIZE(2);
986   template <typename T, typename T2> constexpr auto
987   operator () (const T &a, const T2 &b) const HB_AUTO_RETURN (a % b)
988 }
989 HB_FUNCOBJ (hb_mod);
990 struct
991 {
992   template <typename T> constexpr auto
993   operator () (const T &a) const HB_AUTO_RETURN (+a)
994 }
995 HB_FUNCOBJ (hb_pos);
996 struct
997 {
998   template <typename T> constexpr auto
999   operator () (const T &a) const HB_AUTO_RETURN (-a)
1000 }
1001 HB_FUNCOBJ (hb_neg);
1002 struct
1003 {
1004   template <typename T> constexpr auto
1005   operator () (T &a) const HB_AUTO_RETURN (++a)
1006 }
1007 HB_FUNCOBJ (hb_inc);
1008 struct
1009 {
1010   template <typename T> constexpr auto
1011   operator () (T &a) const HB_AUTO_RETURN (--a)
1012 }
1013 HB_FUNCOBJ (hb_dec);
1014 
1015 
1016 /* Compiler-assisted vectorization. */
1017 
1018 /* Type behaving similar to vectorized vars defined using __attribute__((vector_size(...))),
1019  * basically a fixed-size bitset. */
1020 template <typename elt_t, unsigned int byte_size>
1021 struct hb_vector_size_t
1022 {
operator []hb_vector_size_t1023   elt_t& operator [] (unsigned int i) { return v[i]; }
operator []hb_vector_size_t1024   const elt_t& operator [] (unsigned int i) const { return v[i]; }
1025 
clearhb_vector_size_t1026   void clear (unsigned char v = 0) { memset (this, v, sizeof (*this)); }
1027 
1028   template <typename Op>
processhb_vector_size_t1029   hb_vector_size_t process (const Op& op) const
1030   {
1031     hb_vector_size_t r;
1032     for (unsigned int i = 0; i < ARRAY_LENGTH (v); i++)
1033       r.v[i] = op (v[i]);
1034     return r;
1035   }
1036   template <typename Op>
processhb_vector_size_t1037   hb_vector_size_t process (const Op& op, const hb_vector_size_t &o) const
1038   {
1039     hb_vector_size_t r;
1040     for (unsigned int i = 0; i < ARRAY_LENGTH (v); i++)
1041       r.v[i] = op (v[i], o.v[i]);
1042     return r;
1043   }
operator |hb_vector_size_t1044   hb_vector_size_t operator | (const hb_vector_size_t &o) const
1045   { return process (hb_bitwise_or, o); }
operator &hb_vector_size_t1046   hb_vector_size_t operator & (const hb_vector_size_t &o) const
1047   { return process (hb_bitwise_and, o); }
operator ^hb_vector_size_t1048   hb_vector_size_t operator ^ (const hb_vector_size_t &o) const
1049   { return process (hb_bitwise_xor, o); }
operator ~hb_vector_size_t1050   hb_vector_size_t operator ~ () const
1051   { return process (hb_bitwise_neg); }
1052 
1053   private:
1054   static_assert (0 == byte_size % sizeof (elt_t), "");
1055   elt_t v[byte_size / sizeof (elt_t)];
1056 };
1057 
1058 
1059 #endif /* HB_ALGS_HH */
1060