source: libcfa/src/collections/array.hfa@ b28ce93

Last change on this file since b28ce93 was ee70ff5, checked in by Peter A. Buhr <pabuhr@…>, 6 months ago

harmonize length computations to function name "len"

  • Property mode set to 100644
File size: 10.6 KB
Line 
1#pragma once
2
3
4
5forall( __CFA_tysys_id_only_X & ) struct tag {};
6#define ttag(T) ((tag(T)){})
7#define ztag(n) ttag(n)
8
9#ifdef __CFA_DEBUG__
10#define subcheck( arr, sub, len ) \
11 if ( (sub) < 0 || (sub) >= (len) ) \
12 abort( "Subscript %ld exceeds dimension range [0,%zu) for array %p.\n", \
13 (sub), (len), (arr) )
14#define subchecku( arr, sub, len ) \
15 if ( (sub) >= (len) ) \
16 abort( "Subscript %ld exceeds dimension range [0,%zu) for array %p.\n", \
17 (sub), (len), (arr) )
18#else
19#define subcheck( arr, sub, len ) do {} while (0)
20#define subchecku( arr, sub, len ) do {} while (0)
21#endif
22
23//
24// The `array` macro is the public interface.
25// It computes the type of a dense (trivially strided) array.
26// All user-declared objects are dense arrays.
27//
28// The `arpk` (ARray with PacKing info explicit) type is, generally, a slice with _any_ striding.
29// This type is meant for internal use.
30// CFA programmers should not instantiate it directly, nor access its field.
31// CFA programmers should call ?[?] on it.
32// Yet user-given `array(stuff)` expands to `arpk(stuff')`.
33// The comments here explain the resulting internals.
34//
35// Just as a plain-C "multidimesional" array is really array-of-array-of-...,
36// so does arpk generally show up as arpk-of-arpk-of...
37//
38// In the example of `array(float, 3, 4, 5) a;`,
39// `typeof(a)` is an `arpk` instantiation.
40// These comments explain _its_ arguments, i.e. those of the topmost `arpk` level.
41//
42// [N] : the number of elements in `a`; 3 in the example
43// S : carries the stride size (distance in bytes between &myA[0] and &myA[1]), in sizeof(S);
44// same as Timmed when striding is trivial, same as Timmed in the example
45// Timmed : (T-immediate) the inner type; conceptually, `typeof(a)` is "arpk of Timmed";
46// array(float, 4, 5) in the example
47// Tbase : (T-base) the deepest element type that is not arpk; float in the example
48//
49forall( [N], S & | sized(S), Timmed &, Tbase & ) {
50 //
51 // Single-dim array struct (with explicit packing and atom)
52 //
53 struct arpk {
54 S strides[N];
55 };
56
57 // About the choice of integral types offered as subscript overloads:
58 // Intent is to cover these use cases:
59 // a[0] // i : zero_t
60 // a[1] // i : one_t
61 // a[2] // i : int
62 // float foo( ptrdiff_t i ) { return a[i]; } // i : ptrdiff_t
63 // float foo( size_t i ) { return a[i]; } // i : size_t
64 // forall( [N] ) ... for( i; N ) { total += a[i]; } // i : typeof( sizeof(42) )
65 // for( i; 5 ) { total += a[i]; } // i : int
66 //
67 // It gets complicated by:
68 // - CFA does overloading on concrete types, like int and unsigned int, not on typedefed
69 // types like size_t. So trying to overload on ptrdiff_t vs int works in 64-bit mode
70 // but not in 32-bit mode.
71 // - Given bug of Trac #247, CFA gives sizeof expressions type unsigned long int, when it
72 // should give them type size_t.
73 //
74 // gcc -m32 cfa -m32 given bug gcc -m64 (and cfa)
75 // ptrdiff_t int int long int
76 // size_t unsigned int unsigned int unsigned long int
77 // typeof( sizeof(42) ) unsigned int unsigned long int unsigned long int
78 // int int int int
79 //
80 // So the solution must support types {zero_t, one_t, int, unsigned int, long int, unsigned long int}
81 //
82 // The solution cannot rely on implicit conversions (e.g. just have one overload for ptrdiff_t)
83 // because assertion satisfaction requires types to match exacly. Both higher-dimensional
84 // subscripting and operations on slices use asserted subscript operators. The test case
85 // array-container/array-sbscr-cases covers the combinations. Mike beleives that commenting out
86 // any of the current overloads leads to one of those cases failing, either on 64- or 32-bit.
87 // Mike is open to being shown a smaller set of overloads that still passes the test.
88
89 static inline Timmed & ?[?]( arpk( N, S, Timmed, Tbase ) & a, zero_t ) {
90 subcheck( a, 0L, N );
91 return (Timmed &)a.strides[0];
92 }
93
94 static inline Timmed & ?[?]( arpk( N, S, Timmed, Tbase ) & a, one_t ) {
95 subcheck( a, 1L, N );
96 return (Timmed &)a.strides[1];
97 }
98
99 static inline Timmed & ?[?]( arpk( N, S, Timmed, Tbase ) & a, int i ) {
100 subcheck( a, (long int)i, N );
101 return (Timmed &)a.strides[i];
102 }
103
104 static inline const Timmed & ?[?]( const arpk( N, S, Timmed, Tbase ) & a, int i ) {
105 subcheck( a, (long int)i, N );
106 return (Timmed &)a.strides[i];
107 }
108
109 static inline Timmed & ?[?]( arpk( N, S, Timmed, Tbase ) & a, unsigned int i ) {
110 subchecku( a, (unsigned long int)i, N );
111 return (Timmed &)a.strides[i];
112 }
113
114 static inline const Timmed & ?[?]( const arpk( N, S, Timmed, Tbase ) & a, unsigned int i ) {
115 subchecku( a, (unsigned long int)i, N );
116 return (Timmed &)a.strides[i];
117 }
118
119 static inline Timmed & ?[?]( arpk( N, S, Timmed, Tbase ) & a, long int i ) {
120 subcheck( a, i, N );
121 return (Timmed &)a.strides[i];
122 }
123
124 static inline const Timmed & ?[?]( const arpk( N, S, Timmed, Tbase ) & a, long int i ) {
125 subcheck( a, i, N );
126 return (Timmed &)a.strides[i];
127 }
128
129 static inline Timmed & ?[?]( arpk( N, S, Timmed, Tbase ) & a, unsigned long int i ) {
130 subchecku( a, i, N );
131 return (Timmed &)a.strides[i];
132 }
133
134 static inline const Timmed & ?[?]( const arpk( N, S, Timmed, Tbase ) & a, unsigned long int i ) {
135 subchecku( a, i, N );
136 return (Timmed &)a.strides[i];
137 }
138
139 static inline size_t len( arpk( N, S, Timmed, Tbase ) & ) {
140 return N;
141 }
142
143 static inline void __taglen( tag(arpk( N, S, Timmed, Tbase )), tag(N) ) {}
144}
145
146// RAII pattern has workarounds for
147// - Trac 226: Simplest handling would be, require immediate element to be otype, let autogen
148// raii happen. Performance on even a couple dimensions is unacceptable because of exponential
149// thunk creation: ?{}() needs all four otype funcs from next level, so does ^?{}(), so do the
150// other two. This solution offers ?{}() that needs only ?{}(), and similar for ^?{}.
151
152// skip initializing elements
153// array(float, 5) x = { delay_init };
154enum () delay_init_t { delay_init };
155forall( [N], S & | sized(S), Timmed &, Tbase & )
156static inline void ?{}( arpk( N, S, Timmed, Tbase ) & this, delay_init_t ) {
157 void ?{}( S (&)[N] ) {}
158 ?{}(this.strides);
159}
160
161// call default ctor on elements
162// array(float, 5) x;
163forall( [N], S & | sized(S), Timmed &, Tbase & | { void ?{}( Timmed & ); } )
164static inline void ?{}( arpk( N, S, Timmed, Tbase ) & this ) {
165 ?{}( this, delay_init );
166 for (i; N) ?{}( (Timmed &)this.strides[i] );
167}
168
169forall( [N], S & | sized(S), Timmed &, Tbase & | { void ^?{}( Timmed & ); } )
170static inline void ^?{}( arpk( N, S, Timmed, Tbase ) & this ) {
171 void ^?{}( S (&)[N] ) {}
172 ^?{}(this.strides);
173
174 for (i; N ) {
175 ^?{}( (Timmed &)this.strides[N-i-1] );
176 }
177}
178
179
180//
181// Sugar for declaring array structure instances
182//
183
184forall( Te * )
185static inline Te mkar_( tag(Te) ) {}
186
187forall( [N], ZTags ... , Trslt &, Tatom & | { Trslt mkar_( tag(Tatom), ZTags ); } )
188static inline arpk( N, Trslt, Trslt, Tatom) mkar_( tag(Tatom), tag(N), ZTags ) {}
189
190// based on https://stackoverflow.com/questions/1872220/is-it-possible-to-iterate-over-arguments-in-variadic-macros
191
192 // Make a FOREACH macro
193 #define FE_0(WHAT)
194 #define FE_1(WHAT, X) WHAT(X)
195 #define FE_2(WHAT, X, ...) WHAT(X)FE_1(WHAT, __VA_ARGS__)
196 #define FE_3(WHAT, X, ...) WHAT(X)FE_2(WHAT, __VA_ARGS__)
197 #define FE_4(WHAT, X, ...) WHAT(X)FE_3(WHAT, __VA_ARGS__)
198 #define FE_5(WHAT, X, ...) WHAT(X)FE_4(WHAT, __VA_ARGS__)
199 //... repeat as needed
200
201 #define GET_MACRO(_0,_1,_2,_3,_4,_5,NAME,...) NAME
202 #define FOR_EACH(action,...) \
203 GET_MACRO(_0,__VA_ARGS__,FE_5,FE_4,FE_3,FE_2,FE_1,FE_0)(action,__VA_ARGS__)
204
205#define COMMA_ttag(X) , ttag(X)
206#define array( TE, ...) typeof( mkar_( ttag(TE) FOR_EACH( COMMA_ttag, __VA_ARGS__ ) ) )
207
208#define COMMA_ztag(X) , ztag(X)
209#define zarray( TE, ...) typeof( mkar_( ttag(TE) FOR_EACH( COMMA_ztag, __VA_ARGS__ ) ) )
210
211//
212// Sugar for multidimensional indexing
213//
214
215// Core -[[-,-,-]] operator
216
217#ifdef TRY_BROKEN_DESIRED_MD_SUBSCRIPT
218
219// Desired form. One definition with recursion on IxBC (worked until Jan 2021, see trac #__TODO__)
220
221forall( TA &, TB &, TC &, IxAB, IxBC ... | { TB & ?[?]( TA &, IxAB ); TC & ?[?]( TB &, IxBC ); } )
222static inline TC & ?[?]( TA & this, IxAB ab, IxBC bc ) {
223 return this[ab][bc];
224}
225
226#else
227
228// Workaround form. Listing all possibilities up to 4 dims.
229
230forall( TA &, TB &, TC &, IxAB_0, IxBC | { TB & ?[?]( TA &, IxAB_0 ); TC & ?[?]( TB &, IxBC ); } )
231static inline TC & ?[?]( TA & this, IxAB_0 ab, IxBC bc ) {
232 return this[ab][bc];
233}
234
235forall( TA &, TB &, TC &, IxAB_0, IxAB_1, IxBC | { TB & ?[?]( TA &, IxAB_0, IxAB_1 ); TC & ?[?]( TB &, IxBC ); } )
236static inline TC & ?[?]( TA & this, IxAB_0 ab0, IxAB_1 ab1, IxBC bc ) {
237 return this[[ab0,ab1]][bc];
238}
239
240forall( TA &, TB &, TC &, IxAB_0, IxAB_1, IxAB_2, IxBC | { TB & ?[?]( TA &, IxAB_0, IxAB_1, IxAB_2 ); TC & ?[?]( TB &, IxBC ); } )
241static inline TC & ?[?]( TA & this, IxAB_0 ab0, IxAB_1 ab1, IxAB_2 ab2, IxBC bc ) {
242 return this[[ab0,ab1,ab2]][bc];
243}
244
245#endif
246
247// Available for users to work around Trac #265
248// If `a[...0...]` isn't working, try `a[...ix0...]` instead.
249
250#define ix0 ((ptrdiff_t)0)
251
252
253
254//
255// Rotation
256//
257
258// Base
259forall( [Nq], Sq & | sized(Sq), Tbase & )
260static inline tag(arpk( Nq, Sq, Tbase, Tbase )) enq_( tag(Tbase ), tag(Nq), tag(Sq), tag(Tbase ) ) {
261 tag(arpk( Nq, Sq, Tbase, Tbase )) ret;
262 return ret;
263}
264
265// Rec
266forall( [Nq], Sq & | sized(Sq), [N], S & | sized(S), recq &, recr &, Tbase & | { tag(recr) enq_( tag(Tbase), tag(Nq), tag(Sq), tag(recq) ); } )
267static inline tag(arpk( N, S, recr, Tbase )) enq_( tag(Tbase ), tag(Nq), tag(Sq), tag(arpk( N, S, recq, Tbase )) ) {
268 tag(arpk( N, S, recr, Tbase )) ret;
269 return ret;
270}
271
272// Wrapper
273extern struct all_t {} all;
274forall( [N], S & | sized(S), Te &, result &, Tbase & | { tag(result) enq_( tag(Tbase), tag(N), tag(S), tag(Te) ); } )
275static inline result & ?[?]( arpk( N, S, Te, Tbase ) & this, all_t ) {
276 return (result&) this;
277}
278
279//
280// Trait of array or slice
281//
282
283// desired:
284// forall( A &, Tv &, [N] )
285// trait ar {
286// Tv& ?[?]( A &, zero_t );
287// Tv& ?[?]( A &, one_t );
288// Tv& ?[?]( A &, int );
289// ...
290// size_t len( A & );
291// void __taglen( tag(C), tag(N) );
292// };
293
294// working around N's not being accepted as arguments to traits
295
296#define ar( A, Tv, N ) { \
297 Tv& ?[?]( A &, zero_t ); \
298 Tv& ?[?]( A &, one_t ); \
299 Tv& ?[?]( A &, int ); \
300 Tv& ?[?]( A &, unsigned int ); \
301 Tv& ?[?]( A &, long int ); \
302 Tv& ?[?]( A &, unsigned long int ); \
303 size_t len( A & ); \
304 void __taglen( tag(A), tag(N) ); \
305}
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