]>
iEval git - app-scheme79asm.git/blob - lib/App/Scheme79asm.pm
1 package App
:: Scheme79asm
;
7 use Data
:: Dumper qw
/Dumper/ ;
8 use Data
:: SExpression qw
/consp scalarp/ ;
9 use Scalar
:: Util qw
/looks_like_number/ ;
11 our $VERSION = '0.001001' ;
39 * consp
= * Data
:: SExpression
:: consp
;
40 * scalarp
= * Data
:: SExpression
:: scalarp
;
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 ;
48 die 'Type of toplevel is not atom: ' . Dumper
( $type ), " \n " unless scalarp
( $type );
51 $addr = $self ->{ freeptr
} + 1 ;
52 $self ->{ freeptr
} += @addrs ;
53 $self -> process ( $addrs [ $_ ], $addr + $_ ) for 0 .. $#addrs ;
58 $addr = $self -> process ( $addr ) if ref $addr eq 'ARRAY' ;
59 die 'Addr of toplevel is not atom: ' , Dumper
( $addr ), " \n " unless scalarp
( $addr );
61 my ( $comment_type , $comment_addr ) = ( $type , $addr );
63 unless ( looks_like_number
$addr ) { # is symbol
64 unless ( exists $self ->{ symbols
}{ $addr }) {
65 $self ->{ symbols
}{ $addr } = $self ->{ nsymbols
};
68 $addr = $self ->{ symbols
}{ $addr }
71 die 'Computed addr is not a number: ' , Dumper
( $addr ), " \n " unless looks_like_number
$addr ;
73 if ( ref $type eq 'Data::SExpression::Symbol' ) {
74 die "No such type: $type \n " unless exists $TYPES { $type };
75 $type = $TYPES { $type };
76 } elsif (! looks_like_number
$type ) {
77 die "Type is not a number or symbol: $type \n "
80 die "Type too large: $type \n " unless $type < ( 1 << $self ->{ type_bits
});
81 die "Addr too large: $addr \n " unless $addr < ( 1 << $self ->{ addr_bits
});
82 my $result = ( $type << $self ->{ addr_bits
}) + $addr ;
85 $location = $self ->{ freeptr
}
87 $self ->{ memory
}[ $location ] = $result ;
88 $self ->{ comment
}[ $location ] = " $comment_type $comment_addr " ;
93 my ( $self , $string ) = @_ ;
94 my $ds = Data
:: SExpression
-> new ({ symbol_case
=> 'up' , use_symbol_class
=> 1 , fold_lists
=> 1 });
98 last if $string =~ /^\s*$/ ;
99 ( $sexp , $string ) = $ds -> read ( $string );
100 $self -> process ( $sexp )
106 $self ->{ memory
}[ 5 ] = $self ->{ memory
}[ $self ->{ freeptr
}];
107 $self ->{ comment
}[ 5 ] = $self ->{ comment
}[ $self ->{ freeptr
}];
108 $self ->{ memory
}[ 4 ] = $self ->{ freeptr
};
109 delete $self ->{ memory
}[ $self ->{ freeptr
}]
113 my ( $class , %args ) = @_ ;
114 $args { type_bits
} // = 3 ;
115 $args { addr_bits
} // = 8 ;
116 $args { freeptr
} // = 6 ;
117 $args { memory
} // = [ 0 , 0 , ( 1 << $args { addr_bits
}), ( 1 << $args { addr_bits
}), 0 , 0 , 0 ];
118 $args { symbols
}{ NIL
} = 0 ;
119 $args { symbols
}{ T
} = 1 ;
121 $args { comment
} = [ '(cdr part of NIL)' , '(car part of NIL)' , '(cdr part of T)' , '(car part of T)' , '(free storage pointer)' , '' , '(result of computation)' ];
126 my ( $self , $fh ) = @_ ;
129 my $bits = $self ->{ type_bits
} + $self ->{ addr_bits
};
130 my $index_length = length $ #{$self->{memory}};
131 my $index_format = '%' . $index_length . 'd' ;
132 for my $index ( 0 .. $ #{$self->{memory}}) {
133 my $val = $self ->{ memory
}[ $index ];
134 my $comment = $self ->{ comment
}[ $index ];
136 $val = "${bits}'d $val "
138 $val = $val ?
sprintf " %d 'b %0 ${bits}b" , $bits , $val : '0' ;
140 my $spaces = ' ' x
( $bits + 5 - ( length $val ));
141 $index = sprintf $index_format , $index ;
142 say $fh "mem[ $index ] <= $val ; $spaces // $comment "
146 sub parse_and_print
{
147 my ( $self , $string , $fh ) = @_ ;
148 $self -> parse ( $string );
160 App::Scheme79asm - assemble sexp to Verilog ROM for SIMPLE processor
164 use App::Scheme79asm;
165 my $asm = App::Scheme79asm->new(type_bits => 3, addr_bits => 5);
166 $asm->parse_and_print('(number 70)');
170 SIMPLE is a LISP processor defined in the 1979
171 B<Design of LISP-Based Processors> paper by Steele and Sussman.
173 The SIMPLE processor expects input in a particular tagged-pointer
174 format. This module takes a string containing a sequence of
175 S-expressions. Each S-expression is a list of one of three types:
177 C<(tag value)>, for example C<(symbol nil)>, represents a value to be
178 put in memory (for example a number, or a symbol, or a variable
181 C<(tag list)>, where C<list> is of one of these three types,
182 represents a tagged pointer. In this case, C<list> is (recursively)
183 laid out in memory as per these rules, and a pointer to that location
184 (and tagged C<tag>) is put somewhere in memory.
186 C<(tag list1 list2)>, where C<list1> and C<list2> are of one of these
187 three types (not necessarily the same type). In this case, C<list1>
188 and C<list2> are (recursively) laid out in memory such that C<list1>
189 is at position X and C<list2> is at position X+1, and a pointer of
190 type tag and value X is put somewhere in memory.
192 After this process the very last pointer placed in memory is moved to
193 the special location 5 (which is where SIMPLE expects to find the
194 expression to be evaluated).
196 In normal use a single S-expression will be supplied, representing an
199 The B<parse_and_print> method takes such a string and prints a block
200 of verilog code assigning the memory contents to an array named
203 More documentation and features to follow.
207 L<http://repository.readscheme.org/ftp/papers/ai-lab-pubs/AIM-514.pdf>
211 Marius Gavrilescu, E<lt>marius@ieval.roE<gt>
213 =head1 COPYRIGHT AND LICENSE
215 Copyright (C) 2018 by Marius Gavrilescu
217 This library is free software; you can redistribute it and/or modify
218 it under the same terms as Perl itself, either Perl version 5.24.3 or,
219 at your option, any later version of Perl 5 you may have available.
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