Class: HDLRuby::Low::Select

Inherits:
Operation show all
Defined in:
lib/HDLRuby/hruby_low.rb,
lib/HDLRuby/hruby_low2c.rb,
lib/HDLRuby/hruby_low2hdr.rb,
lib/HDLRuby/hruby_low2vhd.rb,
lib/HDLRuby/hruby_verilog.rb,
lib/HDLRuby/hruby_low2high.rb,
lib/HDLRuby/hruby_low_mutable.rb,
lib/HDLRuby/hruby_low_skeleton.rb,
lib/HDLRuby/hruby_low_fix_types.rb,
lib/HDLRuby/hruby_low_with_bool.rb,
lib/HDLRuby/hruby_low_bool2select.rb,
lib/HDLRuby/hruby_low_casts_without_expression.rb

Overview

Describes a selection operation (generalization of the ternary operator).

NOTE: choice is using the value of +select+ as an index.

Direct Known Subclasses

High::Select

Constant Summary

Constants included from Low2Symbol

Low2Symbol::Low2SymbolPrefix, Low2Symbol::Low2SymbolTable, Low2Symbol::Symbol2LowTable

Instance Attribute Summary collapse

Attributes inherited from Operation

#operator

Attributes inherited from Expression

#type

Attributes included from Hparent

#parent

Instance Method Summary collapse

Methods inherited from Operation

#set_operator!

Methods inherited from Expression

#break_types!, #extract_selects_to!, #fix_scope_refnames!, #leftvalue?, #replace_names!, #rightvalue?, #set_type!, #signal2subs!, #statement, #to_c_expr

Methods included from Low2Symbol

#to_sym

Methods included from Hparent

#absolute_ref, #hierarchy, #no_parent!, #scope

Constructor Details

#initialize(type, operator, select, *choices) ⇒ Select

Creates a new operator with +type+ selecting from the value of +select+ one of the +choices+. def initialize(operator,select,*choices)



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# File 'lib/HDLRuby/hruby_low.rb', line 5506

def initialize(type,operator,select,*choices)
    # Initialize as a general operation.
    # super(operator)
    super(type,operator)
    # Check and set the selection.
    unless select.is_a?(Expression)
        raise AnyError,
              "Invalid class for an expression: #{select.class}"
    end
    @select = select
    # And set its parent.
    select.parent = self
    # Check and set the choices.
    @choices = []
    choices.each do |choice|
        self.add_choice(choice)
    end
end

Instance Attribute Details

#select ⇒ Object (readonly)

The selection child (connection).



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# File 'lib/HDLRuby/hruby_low.rb', line 5501

def select
  @select
end

Instance Method Details

#add_choice(choice) ⇒ Object

Adds a +choice+.



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# File 'lib/HDLRuby/hruby_low.rb', line 5574

def add_choice(choice)
    unless choice.is_a?(Expression)
        raise AnyError,
              "Invalid class for an expression: #{choice.class}"
    end
    # Set the parent of the choice.
    choice.parent = self
    # And add it.
    @choices << choice
    choice
end

#boolean? ⇒ Boolean

Tells if the expression is boolean.

Returns:

  • (Boolean) 


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# File 'lib/HDLRuby/hruby_low_with_bool.rb', line 152

def boolean?
    # Boolean if all the choices are boolean.
    return !self.each_choice.any? {|c| !c.boolean? }
end

#boolean_in_assign2select ⇒ Object

Converts booleans in assignments to select operators.



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# File 'lib/HDLRuby/hruby_low_bool2select.rb', line 265

def boolean_in_assign2select
    # Recurse on the sub node.
    return Select.new(self.type,"?", 
                      self.select.boolean_in_assign2select,
                      *self.each_choice.map do |choice|
                          choice.boolean_in_assign2select
                      end )
    return self
end

#casts_without_expression! ⇒ Object

Extracts the expressions from the casts.



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# File 'lib/HDLRuby/hruby_low_casts_without_expression.rb', line 265

def casts_without_expression!
    # Recurse on the sub node.
    # return Select.new(self.type,"?", 
    #                   self.select.casts_without_expression,
    #                   *self.each_choice.map do |choice|
    #                       choice.casts_without_expression
    #                   end )
    self.set_select!(self.select.casts_without_expression!)
    self.map_choices! { |choice| choice.casts_without_expression! }
    return self
end

#clone ⇒ Object

Clones the select (deeply)



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# File 'lib/HDLRuby/hruby_low.rb', line 5647

def clone
    return Select.new(@type, self.operator, @select.clone,
                      *@choices.map {|choice| choice.clone } )
end

#delete_choice!(choice) ⇒ Object

Deletes a choice.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 1537

def delete_choice!(choice)
    if @choices.include?(choice) then
        # The choice is present, delete it.
        @choices.delete(choice)
        # And remove its parent.
        choice.parent = nil
    end
    choice
end

#each_choice(&ruby_block) ⇒ Object

Iterates over the choices.

Returns an enumerator if no ruby block is given.



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# File 'lib/HDLRuby/hruby_low.rb', line 5589

def each_choice(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_choice) unless ruby_block
    # A ruby block? Apply it on each choice.
    @choices.each(&ruby_block)
end

#each_deep(&ruby_block) ⇒ Object

Iterates over each object deeply.

Returns an enumerator if no ruby block is given.



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# File 'lib/HDLRuby/hruby_low.rb', line 5537

def each_deep(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_deep) unless ruby_block
    # A ruby block? First apply it to current.
    ruby_block.call(self)
    # Then apply on the type.
    self.type.each_deep(&ruby_block)
    # Then apply on the select.
    self.select.each_deep(&ruby_block)
    # Then apply on the choices.
    self.each_choice do |choice|
        choice.each_deep(&ruby_block)
    end
end

#each_node(&ruby_block) ⇒ Object Also known as: each_expression

Iterates over the expression children if any.



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# File 'lib/HDLRuby/hruby_low.rb', line 5602

def each_node(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_node) unless ruby_block
    # A ruby block? Apply it on the children.
    ruby_block.call(@select)
    @choices.each(&ruby_block)
end

#each_node_deep(&ruby_block) ⇒ Object

Iterates over the nodes deeply if any.



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# File 'lib/HDLRuby/hruby_low.rb', line 5613

def each_node_deep(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_node_deep) unless ruby_block
    # A ruby block? First apply it to current.
    ruby_block.call(self)
    # And recurse on the children.
    @select.each_node_deep(&ruby_block)
    @choices.each { |choice| choice.each_node_deep(&ruby_block) }
end

#each_ref_deep(&ruby_block) ⇒ Object

Iterates over all the references encountered in the expression.

NOTE: do not iterate inside the references.



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# File 'lib/HDLRuby/hruby_low.rb', line 5626

def each_ref_deep(&ruby_block)
    # No ruby block? Return an enumerator.
    return to_enum(:each_ref_deep) unless ruby_block
    # puts "each_ref_deep for Select"
    # A ruby block?
    # Recurse on the children.
    self.select.each_ref_deep(&ruby_block)
    self.each_choice do |choice|
        choice.each_ref_deep(&ruby_block)
    end
end

#eql?(obj) ⇒ Boolean

Comparison for hash: structural comparison.

Returns:

  • (Boolean) 


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# File 'lib/HDLRuby/hruby_low.rb', line 5553

def eql?(obj)
    # General comparison.
    return false unless super(obj)
    # Specific comparison.
    return false unless obj.is_a?(Select)
    return false unless @select.eql?(obj.select)
    idx = 0
    obj.each_choice do |choice|
        return false unless @choices[idx].eql?(choice)
        idx += 1
    end
    return false unless idx == @choices.size
    return true
end

#explicit_types(type = nil) ⇒ Object

Explicit the types conversions in the selection where +type+ is the expected type of the condition if any.



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# File 'lib/HDLRuby/hruby_low_fix_types.rb', line 336

def explicit_types(type = nil)
    # If there is no type to match, use the one of the selection.
    type = self.type unless type
    # Each choice child must match the type.
    return Select.new(type,self.operator,self.select.clone,
          *self.each_choice.map { |choice| choice.explicit_types(type)})
end

#get_choice(index) ⇒ Object

Gets a choice by +index+.



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# File 'lib/HDLRuby/hruby_low.rb', line 5597

def get_choice(index)
    return @choices[index]
end

#hash ⇒ Object

Hash function.



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# File 'lib/HDLRuby/hruby_low.rb', line 5569

def hash
    return [super,@select,@choices].hash
end

#immutable? ⇒ Boolean

Tells if the expression is immutable (cannot be written.)

Returns:

  • (Boolean) 


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# File 'lib/HDLRuby/hruby_low.rb', line 5526

def immutable?
    # Immutable if children are all immutable.
    return self.select.constant &&
      self.each_choice.reduce(true) do |r,c|
        r && c.immutable?
    end
end

#map_choices!(&ruby_block) ⇒ Object

Maps on the choices.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 1528

def map_choices!(&ruby_block)
    @choices.map! do |choice|
        choice = ruby_block.call(choice)
        choice.parent = self unless choice.parent
        choice
    end
end

#map_nodes!(&ruby_block) ⇒ Object Also known as: map_expressions!

Maps on the children.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 1548

def map_nodes!(&ruby_block)
    @select = ruby_block.call(@select)
    @select.parent = self unless @select.parent
    map_choices!(&ruby_block)
end

#replace_expressions!(node2rep) ⇒ Object

Replaces sub expressions using +node2rep+ table indicating the node to replace and the corresponding replacement. Returns the actually replaced nodes and their corresponding replacement.

NOTE: the replacement is duplicated.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 1562

def replace_expressions!(node2rep)
    # First recurse on the children.
    res = {}
    self.each_node do |node|
        res.merge!(node.replace_expressions!(node2rep))
    end
    # Is there a replacement to do on the select?
    rep = node2rep[self.select]
    if rep then
        # Yes, do it.
        rep = rep.clone
        node = self.select
        # node.set_parent!(nil)
        self.set_select!(rep)
        # And register the replacement.
        res[node] = rep
    end
    # Is there a replacement of on a choice.
    self.map_choices! do |choice|
        rep = node2rep[choice]
        if rep then
            # Yes, do it.
            rep = rep.clone
            node = choice
            # node.set_parent!(nil)
            # And register the replacement.
            res[node] = rep
            rep
        else
            choice
        end
    end
    return res
end

#set_select!(select) ⇒ Object

Sets the select.



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# File 'lib/HDLRuby/hruby_low_mutable.rb', line 1516

def set_select!(select)
    # Check and set the selection.
    unless select.is_a?(Expression)
        raise AnyError,
              "Invalid class for an expression: #{select.class}"
    end
    @select = select
    # And set its parent.
    select.parent = self
end

#to_c(res, level = 0) ⇒ Object

Generates the C text of the equivalent HDLRuby code.

+level+ is the hierachical level of the object.

def to_c(level = 0)

def to_c(res,level = 0) # Gather the possible selection choices. expressions = self.each_choice.to_a # Create the resulting string. # res = "( res << "({\n" # Overrides the upper sel, src0, src1, ..., and dst... # And allocates a new value for dst. res << (" " * ((level+1)*3)) res << "Value sel;\n" res << (" " * ((level+1)*3)) res << "Value " res << expressions.size.times.map do |i| "src#{i" end.join(",") res << ";\n" res << (" " * ((level+1)*3)) res << "Value dst = get_value();\n" # Save the state of the value pool. res << (" " * ((level+1)*3)) res << "unsigned int pool_state = get_value_pos();\n" # Compute the selection. res << (" " * ((level+1)*3)) # res << "sel = #HDLRuby::Low::Select.selfself.selectself.select.to_c(level+2);\n" res << "sel = " self.select.to_c(res,level+2) res << ";\n" # Compute each choice expression. expressions.each_with_index do |expr,i| res << (" " * ((level+1)*3)) # res << "src#i = #HDLRuby::Low::Select.exprexpr.to_c(level+2);\n" res << "src#i = " expr.to_c(res,level+2) res << ";\n" end # Compute the resulting selection. res << (" " * ((level+1)*3)) res << "select_value(sel,dst,#HDLRuby::Low::Select.expressionsexpressions.size," # res << "#{ |i| "src#{i" }.join(",")}" res << expressions.size.times.map { |i| "src#i" }.join(",") res << ");\n" # Restore the state of the value pool. res << (" " * ((level+1)*3)) res << "set_value_pos(pool_state);\n" # Close the computation. res << (" " * (level*3)) res << "dst; })" return res end Generates the C text of the equivalent HDLRuby code. +level+ is the hierachical level of the object.



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# File 'lib/HDLRuby/hruby_low2c.rb', line 2665

def to_c(res,level = 0)
    # Save the value pool state.
    res << (" " * (level*3)) << "PV;\n"
    # Gather the possible selection choices.
    expressions = self.each_choice.to_a
    # Create the resulting string.
    # Compute the selection.
    self.select.to_c(res,level)
    # Compute each choice expression.
    expressions.each_with_index do |expr,i|
        expr.to_c(res,level)
    end
    # Compute the resulting selection.
    res << (" " * (level*3))
    res << "hselect(#{expressions.size});\n"
    # Restore the value pool state.
    res << (" " * (level*3)) << "RV;\n"
    return res
end

#to_hdr(level = 0) ⇒ Object

Generates the text of the equivalent hdr text. +level+ is the hierachical level of the object.



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# File 'lib/HDLRuby/hruby_low2hdr.rb', line 629

def to_hdr(level = 0)
    # The resulting string.
    res = ""
    # Generate the header.
    res << "mux(" + self.select.to_hdr(level) << ", "
    # Generate the choices
    res << self.each_choice.map do |choice|
        choice.to_hdr(level+1)
    end.join(", ")
    # Close the select.
    res << ")"
    # Return the resulting string.
    return res
end

#to_high ⇒ Object

Creates a new high select expression.



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# File 'lib/HDLRuby/hruby_low2high.rb', line 472

def to_high
    return HDLRuby::High::Select(self.type.to_high,self.operator,
                                 self.select.to_high,
                            self.each_choice.map { |ch| ch.to_high })
end

#to_verilog ⇒ Object

Converts the system to Verilog code.



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# File 'lib/HDLRuby/hruby_verilog.rb', line 1627

def to_verilog
    # Outputs the first and second choices (choice (0) and choice (1)).
    # return "#{self.select.to_verilog} == 1 #{self.operator} #{self.get_choice(0).to_verilog} : #{self.get_choice(1).to_verilog}"
    res = ""
    sels = self.select.to_verilog
    @choices[0..-2].each_with_index do |choice,i|
        res << "#{sels} == #{i} ? #{choice.to_verilog} : "
    end
    res << @choices[-1].to_verilog
    return res
end

#to_vhdl(level = 0, std_logic = false) ⇒ Object

Generates the text of the equivalent HDLRuby::High code. +level+ is the hierachical level of the object.

NOTE: assumes the existance of the mux function.



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# File 'lib/HDLRuby/hruby_low2vhd.rb', line 1390

def to_vhdl(level = 0, std_logic = false)
    # The resulting string.
    res = ""
    # The number of arguments.
    num = @choices.size
    # Generate the header.
    res << "#{Low2VHDL.mux_name(self.type.to_vhdl(level),num)}(" +
            self.select.to_vhdl(level) << ", "
    # Generate the choices
    res << self.each_choice.map do |choice|
        choice.to_vhdl(level+1)
    end.join(", ")
    # Close the select.
    res << ")"
    # Return the resulting string.
    return res
end

#use_name?(*names) ⇒ Boolean

Tell if the expression includes a signal whose name is one of +names+.

Returns:

  • (Boolean) 


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# File 'lib/HDLRuby/hruby_low.rb', line 5639

def use_name?(*names)
    # Recurse on the select.
    return true if @select.use_name?(*names)
    # Recurse on the choices.
    return @choices.any? { |choice| choice.use_name?(*names) }
end