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509643aa MG |
1 | package App::Scheme79asm; |
2 | ||
3 | use 5.014000; | |
4 | use strict; | |
5 | use warnings; | |
6 | ||
4a9c3fa9 | 7 | use Data::Dumper qw/Dumper/; |
509643aa MG |
8 | use Data::SExpression qw/consp scalarp/; |
9 | use Scalar::Util qw/looks_like_number/; | |
10 | ||
3fff77b7 | 11 | our $VERSION = '0.004'; |
509643aa MG |
12 | |
13 | our %TYPES = ( | |
14 | LIST => 0, | |
15 | SYMBOL => 1, | |
4a9c3fa9 | 16 | NUMBER => 1, |
509643aa MG |
17 | VAR => 2, |
18 | VARIABLE => 2, | |
19 | CLOSURE => 3, | |
20 | PROC => 4, | |
21 | PROCEDURE => 4, | |
4a9c3fa9 | 22 | IF => 5, |
509643aa MG |
23 | COND => 5, |
24 | CONDITIONAL => 5, | |
25 | CALL => 6, | |
509643aa MG |
26 | QUOTE => 7, |
27 | QUOTED => 7, | |
4a9c3fa9 MG |
28 | |
29 | MORE => 0, | |
30 | CAR => 1, | |
31 | CDR => 2, | |
32 | CONS => 3, | |
33 | ATOM => 4, | |
34 | PROGN => 5, | |
f0289d3d | 35 | 'REVERSE-LIST' => 6, |
4a9c3fa9 | 36 | FUNCALL => 7, |
509643aa MG |
37 | ); |
38 | ||
39 | *consp = *Data::SExpression::consp; | |
40 | *scalarp = *Data::SExpression::scalarp; | |
41 | ||
42 | sub process { | |
4a9c3fa9 MG |
43 | my ($self, $sexp, $location) = @_; |
44 | die 'Toplevel is not a list: ', Dumper($sexp), "\n" unless ref $sexp eq 'ARRAY'; | |
45 | my ($type, @addrs) = @$sexp; | |
46 | my $addr; | |
47 | ||
48 | die 'Type of toplevel is not atom: '. Dumper($type), "\n" unless scalarp($type); | |
49 | ||
50 | if (@addrs > 1) { | |
51 | $addr = $self->{freeptr} + 1; | |
52 | $self->{freeptr} += @addrs; | |
53 | $self->process($addrs[$_], $addr + $_) for 0 .. $#addrs; | |
54 | } else { | |
55 | $addr = $addrs[0]; | |
56 | } | |
57 | ||
58 | $addr = $self->process($addr) if ref $addr eq 'ARRAY'; | |
59 | die 'Addr of toplevel is not atom: ', Dumper($addr), "\n" unless scalarp($addr); | |
34073a4a | 60 | my ($comment_type, $comment_addr) = ($type, $addr); |
4a9c3fa9 | 61 | die 'Computed addr is not a number: ', Dumper($addr), "\n" unless looks_like_number $addr; |
509643aa | 62 | |
ab8f838f | 63 | if (!looks_like_number $type) { |
509643aa MG |
64 | die "No such type: $type\n" unless exists $TYPES{$type}; |
65 | $type = $TYPES{$type}; | |
509643aa MG |
66 | } |
67 | ||
f0289d3d | 68 | $addr += (1 << $self->{addr_bits}) if $addr < 0; |
509643aa MG |
69 | die "Type too large: $type\n" unless $type < (1 << $self->{type_bits}); |
70 | die "Addr too large: $addr\n" unless $addr < (1 << $self->{addr_bits}); | |
71 | my $result = ($type << $self->{addr_bits}) + $addr; | |
4a9c3fa9 MG |
72 | unless ($location) { |
73 | $self->{freeptr}++; | |
74 | $location = $self->{freeptr} | |
75 | } | |
76 | $self->{memory}[$location] = $result; | |
34073a4a | 77 | $self->{comment}[$location] = "$comment_type $comment_addr"; |
4a9c3fa9 | 78 | $location |
509643aa MG |
79 | } |
80 | ||
81 | sub parse { | |
82 | my ($self, $string) = @_; | |
4a9c3fa9 | 83 | my $ds = Data::SExpression->new({symbol_case => 'up', use_symbol_class => 1, fold_lists => 1}); |
509643aa MG |
84 | |
85 | my $sexp; | |
86 | while () { | |
87 | last if $string =~ /^\s*$/; | |
88 | ($sexp, $string) = $ds->read($string); | |
89 | $self->process($sexp) | |
90 | } | |
91 | } | |
92 | ||
93 | sub finish { | |
94 | my ($self) = @_; | |
95 | $self->{memory}[5] = $self->{memory}[$self->{freeptr}]; | |
34073a4a | 96 | $self->{comment}[5] = $self->{comment}[$self->{freeptr}]; |
509643aa MG |
97 | $self->{memory}[4] = $self->{freeptr}; |
98 | delete $self->{memory}[$self->{freeptr}] | |
99 | } | |
100 | ||
101 | sub new { | |
102 | my ($class, %args) = @_; | |
103 | $args{type_bits} //= 3; | |
104 | $args{addr_bits} //= 8; | |
105 | $args{freeptr} //= 6; | |
106 | $args{memory} //= [0, 0, (1<<$args{addr_bits}), (1<<$args{addr_bits}), 0, 0, 0]; | |
5ff3fe85 MG |
107 | my @default_comments = ('(cdr part of NIL)', '(car part of NIL)', '(cdr part of T)', '(car part of T)', '(free storage pointer)', '', '(result of computation)'); |
108 | for (0 .. $#default_comments) { | |
109 | $args{comment}[$_] = $default_comments[$_] | |
110 | } | |
509643aa MG |
111 | bless \%args, $class |
112 | } | |
113 | ||
f0289d3d MG |
114 | sub print_binary16 { |
115 | my ($self, $fh) = @_; | |
744f5c2a | 116 | $fh //= \*STDOUT; # uncoverable condition right |
f0289d3d | 117 | |
26bb1344 MG |
118 | die "addr_bits + type_bits >= 16\n"if $self->{addr_bits} + $self->{type_bits} > 16; |
119 | ||
f0289d3d MG |
120 | my $length = @{$self->{memory}}; |
121 | print $fh pack('n', $length); | |
122 | for (@{$self->{memory}}) { | |
123 | print $fh pack('n', $_) | |
124 | } | |
125 | } | |
126 | ||
127 | sub print_verilog { | |
509643aa | 128 | my ($self, $fh) = @_; |
744f5c2a | 129 | $fh //= \*STDOUT; # uncoverable condition right |
509643aa MG |
130 | |
131 | my $bits = $self->{type_bits} + $self->{addr_bits}; | |
34073a4a MG |
132 | my $index_length = length $#{$self->{memory}}; |
133 | my $index_format = '%' . $index_length . 'd'; | |
509643aa MG |
134 | for my $index (0 .. $#{$self->{memory}}) { |
135 | my $val = $self->{memory}[$index]; | |
34073a4a | 136 | my $comment = $self->{comment}[$index]; |
509643aa MG |
137 | if ($index == 4) { |
138 | $val = "${bits}'d$val" | |
139 | } else { | |
140 | $val = $val ? sprintf "%d'b%0${bits}b", $bits, $val : '0'; | |
141 | } | |
34073a4a MG |
142 | my $spaces = ' ' x ($bits + 5 - (length $val)); |
143 | $index = sprintf $index_format, $index; | |
744f5c2a MG |
144 | |
145 | print $fh "mem[$index] <= $val;"; | |
146 | print $fh "$spaces // $comment" if defined $comment; | |
147 | print $fh "\n"; | |
509643aa | 148 | } |
f0289d3d MG |
149 | |
150 | } | |
151 | sub parse_and_print_binary16 { | |
152 | my ($self, $string, $fh) = @_; | |
153 | $self->parse($string); | |
154 | $self->finish; | |
155 | $self->print_binary16($fh); | |
509643aa MG |
156 | } |
157 | ||
f0289d3d | 158 | sub parse_and_print_verilog { |
509643aa MG |
159 | my ($self, $string, $fh) = @_; |
160 | $self->parse($string); | |
161 | $self->finish; | |
f0289d3d | 162 | $self->print_verilog($fh); |
509643aa MG |
163 | } |
164 | ||
165 | 1; | |
166 | __END__ | |
167 | ||
168 | =encoding utf-8 | |
169 | ||
170 | =head1 NAME | |
171 | ||
172 | App::Scheme79asm - assemble sexp to Verilog ROM for SIMPLE processor | |
173 | ||
174 | =head1 SYNOPSIS | |
175 | ||
176 | use App::Scheme79asm; | |
177 | my $asm = App::Scheme79asm->new(type_bits => 3, addr_bits => 5); | |
f0289d3d | 178 | $asm->parse_and_print_verilog('(number 70)'); |
509643aa MG |
179 | |
180 | =head1 DESCRIPTION | |
181 | ||
509643aa MG |
182 | SIMPLE is a LISP processor defined in the 1979 |
183 | B<Design of LISP-Based Processors> paper by Steele and Sussman. | |
184 | ||
185 | The SIMPLE processor expects input in a particular tagged-pointer | |
186 | format. This module takes a string containing a sequence of | |
9924aa7b MG |
187 | S-expressions. Each S-expression is a list of one of three types: |
188 | ||
744f5c2a | 189 | C<(tag value)>, for example C<(symbol 2)>, represents a value to be |
9924aa7b | 190 | put in memory (for example a number, or a symbol, or a variable |
5ff3fe85 | 191 | reference). The value must be a number. |
9924aa7b MG |
192 | |
193 | C<(tag list)>, where C<list> is of one of these three types, | |
194 | represents a tagged pointer. In this case, C<list> is (recursively) | |
195 | laid out in memory as per these rules, and a pointer to that location | |
196 | (and tagged C<tag>) is put somewhere in memory. | |
197 | ||
198 | C<(tag list1 list2)>, where C<list1> and C<list2> are of one of these | |
199 | three types (not necessarily the same type). In this case, C<list1> | |
200 | and C<list2> are (recursively) laid out in memory such that C<list1> | |
201 | is at position X and C<list2> is at position X+1, and a pointer of | |
202 | type tag and value X is put somewhere in memory. | |
203 | ||
204 | After this process the very last pointer placed in memory is moved to | |
205 | the special location 5 (which is where SIMPLE expects to find the | |
206 | expression to be evaluated). | |
207 | ||
208 | In normal use a single S-expression will be supplied, representing an | |
209 | entire program. | |
210 | ||
68367057 MG |
211 | The C<tag> is either a number, a type, or a primitive. |
212 | The available types are: | |
509643aa | 213 | |
68367057 MG |
214 | =over |
215 | ||
216 | =item LIST | |
217 | ||
218 | =item SYMBOL (syn. NUMBER) | |
219 | ||
220 | =item VAR (syn. VARIABLE) | |
221 | ||
222 | =item CLOSURE | |
223 | ||
224 | =item PROC (syn. PROCEDURE) | |
225 | ||
226 | =item IF (syn. COND, CONDITIONAL) | |
227 | ||
228 | =item CALL | |
229 | ||
230 | =item QUOTE (syn. QUOTED) | |
231 | ||
232 | =back | |
233 | ||
234 | The available primitives are: | |
235 | ||
236 | =over | |
237 | ||
238 | =item MORE | |
239 | ||
240 | =item CAR | |
241 | ||
242 | =item CDR | |
243 | ||
244 | =item CONS | |
245 | ||
246 | =item ATOM | |
247 | ||
248 | =item PROGN | |
249 | ||
f0289d3d | 250 | =item REVERSE-LIST |
68367057 MG |
251 | |
252 | =item FUNCALL | |
253 | ||
254 | =back | |
255 | ||
256 | The following methods are available: | |
257 | ||
258 | =over | |
259 | ||
260 | =item App::Scheme79asm->B<new>([key => value, key => value, ...]) | |
261 | ||
262 | Create a new assembler object. Takes a list of keys and values, here | |
263 | are the possible keys: | |
264 | ||
265 | =over | |
266 | ||
267 | =item type_bits | |
268 | ||
269 | =item address_bits | |
270 | ||
271 | A word is made of a type and an address, with the type occupying the | |
272 | most significant C<type_bits> (default 3) bits, and the address | |
273 | occupying the least significant C<address_bits> (default 8) bits. | |
5ff3fe85 | 274 | Therefore the word size is C<type_bits + address_bits> (default 11). |
68367057 MG |
275 | |
276 | =item freeptr | |
277 | ||
278 | A pointer to the last used byte in memory (default 6). The program | |
279 | will be laid out starting with location C<freeptr + 1>. | |
280 | ||
281 | =item memory | |
282 | ||
283 | The initial contents of the memory. Note that locations 4, 5, 6 will | |
284 | be overwritten, as will every location larger than the value of | |
285 | C<freeptr>. | |
286 | ||
287 | =item comment | |
288 | ||
289 | The initial comments for memory entries. C<< $comment->[$i] >> is the | |
5ff3fe85 MG |
290 | comment for C<< $memory->[$i] >>. Note that the first 7 entries of |
291 | this array will be overwritten with the default comments. This is | |
292 | useful when using custom initial memory contents and freeptr, because | |
293 | this key can be used to provide comments for the extra reserved | |
294 | locations in memory. | |
68367057 | 295 | |
68367057 MG |
296 | =back |
297 | ||
298 | =item $asm->B<parse>(I<$string>) | |
299 | ||
300 | Parse a sequence of S-expressions and lay it out in memory. | |
301 | Can be called multiple times to lay out multiple sequences of | |
302 | S-expressions one after another. | |
303 | ||
8ff4c670 MG |
304 | =item $asm->B<process>(I<$sexp>) |
305 | ||
306 | Given an already-parsed sexp (meaning a | |
307 | L<Data::SExpression> object), lay it out in memory. | |
308 | Can be called multiple times to lay out multiple sequences of | |
309 | S-expressions one after another. | |
310 | ||
68367057 MG |
311 | =item $asm->B<finish> |
312 | ||
313 | Move the last pointer to position 5, and put the free pointer at | |
314 | position 4. After all sequences of S-expressions have been given to | |
315 | B<parse>, this method should be called. | |
316 | ||
f0289d3d MG |
317 | =item $asm->B<print_binary16>([I<$fh>]) |
318 | ||
319 | Print the length of the memory (as a big-endian 16-bit value), | |
320 | followed by the memory contents as a sequence of big-endian 16-bit | |
321 | values to the given filehandle (default STDOUT). Dies if | |
322 | C<addr_bits + type_bits> is more than 16. | |
323 | ||
324 | Big-endian 16-bit values can be decoded with C<unpack 'n', $value>. | |
325 | ||
326 | =item $asm->B<print_verilog>([I<$fh>]) | |
68367057 MG |
327 | |
328 | Print a block of Verilog code assigning the memory contents to an | |
329 | array named C<mem> to the given filehandle (default STDOUT). | |
330 | ||
f0289d3d MG |
331 | =item $asm->B<parse_and_print_binary16>(I<$string>[, I<$fh>]) |
332 | ||
333 | Convenience method that calls B<parse>($string), B<finish>, and then | |
334 | B<print_binary16>($fh). | |
335 | ||
336 | =item $asm->B<parse_and_print_verilog>(I<$string>[, I<$fh>]) | |
68367057 MG |
337 | |
338 | Convenience method that calls B<parse>($string), B<finish>, and then | |
f0289d3d | 339 | B<print_verilog>($fh). |
68367057 MG |
340 | |
341 | =back | |
509643aa MG |
342 | |
343 | =head1 SEE ALSO | |
344 | ||
345 | L<http://repository.readscheme.org/ftp/papers/ai-lab-pubs/AIM-514.pdf> | |
346 | ||
347 | =head1 AUTHOR | |
348 | ||
349 | Marius Gavrilescu, E<lt>marius@ieval.roE<gt> | |
350 | ||
351 | =head1 COPYRIGHT AND LICENSE | |
352 | ||
353 | Copyright (C) 2018 by Marius Gavrilescu | |
354 | ||
355 | This library is free software; you can redistribute it and/or modify | |
356 | it under the same terms as Perl itself, either Perl version 5.24.3 or, | |
357 | at your option, any later version of Perl 5 you may have available. | |
358 | ||
359 | ||
360 | =cut |