Class: Idl::IntLiteralAst

Inherits:
AstNode
  • Object
show all
Includes:
Rvalue
Defined in:
lib/idlc/ast.rb,
lib/idlc/passes/prune.rb,
lib/idlc/passes/gen_adoc.rb,
lib/idlc/passes/gen_option_adoc.rb

Overview

represents an integer literal

Defined Under Namespace

Classes: Memo

Constant Summary

Constants inherited from AstNode

AstNode::Bits1Type, AstNode::Bits32Type, AstNode::Bits64Type, AstNode::BoolType, AstNode::ConstBoolType, AstNode::PossiblyUnknownBits1Type, AstNode::PossiblyUnknownBits32Type, AstNode::PossiblyUnknownBits64Type, AstNode::ReachableFunctionCacheType, AstNode::StringType, AstNode::VoidType

Instance Attribute Summary

Attributes inherited from AstNode

#children, #input, #interval, #parent

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Rvalue

#max_value, #min_value, #truncate, #values

Methods inherited from AstNode

#always_terminates?, #declaration?, #executable?, extract_base_var_name, #find_ancestor, #find_dst_registers, #find_referenced_csrs, #find_src_registers, #freeze_tree, #input_file, input_from_source_yaml, #inspect, #internal_error, interval_from_source_yaml, #lineno, #lines_around, #nullify_assignments, #pass_find_return_values, #path, #print_ast, #reachable_exceptions, #reachable_functions, #set_input_file, #set_input_file_unless_already_set, #source_line_file_offsets, #source_starting_offset, #source_yaml, #starting_line, #truncation_warn, #type_error, #unindent, value_else, #value_else, value_error, #value_error, value_try, #value_try, write_back_nested

Constructor Details

#initialize(input, interval, text) ⇒ IntLiteralAst

Returns a new instance of IntLiteralAst.



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# File 'lib/idlc/ast.rb', line 7479

def initialize(input, interval, text)
  @text = text
  super(input, interval, EMPTY_ARRAY)
  @memo = Memo.new
end

Class Method Details

.from_h(yaml, source_mapper) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7792

def self.from_h(yaml, source_mapper)
  raise "Bad YAML" unless yaml.key?("kind") && yaml.fetch("kind") == "bits_literal"

  input = input_from_source_yaml(yaml.fetch("source"), source_mapper)
  interval = interval_from_source_yaml(yaml.fetch("source"))
  text = "#{yaml.fetch("width")}'#{yaml.fetch("signed") ? "s" : ""}#{radix_to_verilog(yaml.fetch("radix"))}#{yaml.fetch("value").to_s(yaml.fetch("radix"))}"
  IntLiteralAst.new(
    input, interval, text
  )
end

.radix_to_verilog(r) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7780

def self.radix_to_verilog(r)
  case r
  when 2 then "b"
  when 8 then "o"
  when 10 then "d"
  when 16 then "h"
  else
    raise "bad radix: #{r}"
  end
end

Instance Method Details

#const_eval?(symtab) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/idlc/ast.rb', line 7476

def const_eval?(symtab) = true

#gen_adoc(indent = 0, indent_spaces: 2) ⇒ Object 



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# File 'lib/idlc/passes/gen_adoc.rb', line 147

def gen_adoc(indent = 0, indent_spaces: 2)
  raise "?" if text_value.empty?
  "#{' ' * indent}#{text_value}"
end

#gen_option_adoc ⇒ Object 



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# File 'lib/idlc/passes/gen_option_adoc.rb', line 103

def gen_option_adoc
  if value(nil) == 1 << 65
    "UNDEFINED_LEGAL"
  elsif value(nil) == 1 << 66
    "UNDEFINED_LEGAL_DETERMINISTIC"
  else
    text_value
  end
end

#prune(symtab, forced_type: nil) ⇒ Object 



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# File 'lib/idlc/passes/prune.rb', line 694

def prune(symtab, forced_type: nil)
  if forced_type
    raise "pruning error: attempt to force bitwidth when width is unknown" if forced_type.width.nil? || forced_type.width == :unknown
    s = "#{forced_type.width}'d#{value(symtab)}"
    IntLiteralAst.new(s, 0...s.size, s)
  else
    dup
  end
end

#radix ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7731

def radix
  case text_value.delete("_")
  when /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
    r = T.must(::Regexp.last_match(5))
    if r.empty?
      10
    elsif r == "b"
      2
    elsif r == "o"
      8
    elsif r == "d"
      10
    elsif r == "h"
      16
    else
      raise "unhandled literal"
    end
  when /^0([bdx]?)([0-9a-fA-F]*)(s?)$/
    r = T.must(::Regexp.last_match(1))
    if r.empty?
      10
    elsif r == "b"
      2
    elsif r == "d"
      10
    elsif r == "x"
      16
    else
      raise "unhandled literal: #{r}"
    end
  when /^([0-9]*)(s?)$/
    10
  else
    raise "unhandled literal"
  end
end

#signed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/idlc/ast.rb', line 7714

def signed?
  case text_value.delete("_")
  when /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
    signed = T.must(::Regexp.last_match(4))
    !signed.empty?
  when /^0([bdx]?)([0-9a-fA-F]*)(s?)$/
    signed = T.must(::Regexp.last_match(3))
    !signed.empty?
  when /^([0-9]*)(s?)$/
    signed = T.must(::Regexp.last_match(2))
    !signed.empty?
  else
    raise "unhandled literal"
  end
end

#text_value ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7485

def text_value = @text

#to_h ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7769

def to_h
  {
    "kind" => "bits_literal",
    "width" => (width(nil) == :unknown) ? "MXLEN" : width(nil).to_s,
    "value" => unsigned_value,
    "signed" => signed?,
    "radix" => radix,
    "source" => source_yaml
  }
end

#to_idl ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7711

def to_idl = text_value

#type(symtab) ⇒ Type

Given a specific symbol table, return the type of this node.

Should not be called until #type_check is called with the same arguments

Parameters:

Returns:

  • (Type) —

    The type of the node

Raises:



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# File 'lib/idlc/ast.rb', line 7504

def type(symtab)
  return @memo.type unless @memo.type.nil?

  case text_value.delete("_")
  when /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
    # verilog-style literal
    signed = ::Regexp.last_match(4)
    value = ::Regexp.last_match(6)

    width = width(symtab)

    unless width == :unknown
      type_error("integer width must be positive (is #{width})") unless width.is_a?(Integer) && width.positive?
    end

    qualifiers = signed == "s" ? [:signed, :const] : [:const]
    qualifiers << :known unless T.must(value).include?("x")
    @memo.type =
      if width == :unknown
        Type.new(:bits, width:, max_width: 64, qualifiers:)
      else
        Type.new(:bits, width:, qualifiers:)
      end
  when /^0([bdx]?)([0-9a-fA-F]*)(s?)$/
    # C++-style literal
    signed = ::Regexp.last_match(3)

    qualifiers = signed == "s" ? [:signed, :const, :known] : [:const, :known]
    @memo.type = Type.new(:bits, width: width(symtab), qualifiers:)
  when /^([0-9]*)(s?)$/
    # basic decimal
    signed = ::Regexp.last_match(2)

    qualifiers = signed == "s" ? [:signed, :const, :known] : [:const, :known]
    @memo.type = Type.new(:bits, width: width(symtab), qualifiers:)
  else
    internal_error "Unhandled int value '#{text_value}'"
  end
end

#type_check(symtab, strict:) ⇒ void

This method returns an undefined value.

type check this node and all children

Calls to #type and/or #value may depend on type_check being called first with the same symtab. If not, those functions may raise an AstNode::InternalError

Parameters:

Raises:



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# File 'lib/idlc/ast.rb', line 7488

def type_check(symtab, strict:)
  if text_value.delete("_") =~ /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
    # verilog-style literal
    width = ::Regexp.last_match(1)
    value_text = ::Regexp.last_match(6)

    if width.nil? || width == "MXLEN"
      width = symtab.mxlen.nil? ? 32 : symtab.mxlen # 32 is the min width, which is what we care about here
    end

    # ensure we actually have enough bits to represent the value
    type_error("#{value_text} cannot be represented in #{width} bits") if unsigned_value.bit_length > width.to_i
  end
end

#unsigned_value ⇒ Integer

Returns the unsigned value of this literal (i.e., treating it as unsigned even if the signed specifier is present).

Returns:

  • (Integer) —

    the unsigned value of this literal (i.e., treating it as unsigned even if the signed specifier is present)



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# File 'lib/idlc/ast.rb', line 7630

def unsigned_value
  return @memo.unsigned_value unless @memo.unsigned_value.nil?

  @memo.unsigned_value =
    case text_value.delete("_")
    when /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
      # verilog-style literal
      radix_id = T.must(::Regexp.last_match(5))
      value = T.must(::Regexp.last_match(6))

      radix_id = "d" if radix_id.empty?

      if value.index("x").nil? && value.index("X").nil?
        case radix_id
        when "b"
          value.to_i(2)
        when "o"
          value.to_i(8)
        when "d"
          value.to_i(10)
        when "h"
          value.to_i(16)
        end
      else
        # there is unknown bit(s) in the value
        known_value =
          case radix_id
          when "b"
            value.gsub(/[xX]/, "0").to_i(2)
          when "o"
            value.gsub(/[xX]/, "0").to_i(8)
          when "d"
            raise "impossible"
          when "h"
            value.gsub(/[xX]/, "0").to_i(16)
          end
        unknown_mask =
          case radix_id
          when "b"
            value.gsub("1", "0").gsub(/[xX]/, "1").to_i(2)
          when "o"
            value.gsub(/[0-7]/, "0").gsub(/[xX]/, "7").to_i(8)
          when "d"
            raise "impossible"
          when "h"
            value.gsub(/[0-9a-fA-F]/, "0").gsub(/[xX]/, "f").to_i(16)
          end
        UnknownLiteral.new(known_value, unknown_mask)
      end
    when /^0([bdx]?)([0-9a-fA-F]*)(s?)$/
      # C++-style literal
      radix_id = T.must(::Regexp.last_match(1))
      value = T.must(::Regexp.last_match(2))

      radix_id = "o" if radix_id.empty?

      # @unsigned_value =
      case radix_id
      when "b"
        value.to_i(2)
      when "o"
        value.to_i(8)
      when "d"
        value.to_i(10)
      when "x"
        value.to_i(16)
      end

    when /^([0-9]*)(s?)$/
      # basic decimal
      value = T.must(::Regexp.last_match(1))

      # @unsigned_value = value.to_i(10)
      value.to_i(10)
    else
      internal_error "Unhandled int value '#{text_value}'"
    end
end

#value(symtab) ⇒ Object

Return the compile-time-known value of the node



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# File 'lib/idlc/ast.rb', line 7583

def value(symtab)
  return @memo.value unless @memo.value.nil?

  if text_value.delete("_") =~ /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
    # verilog-style literal
    signed = T.must(::Regexp.last_match(4))
    width = width(symtab)

    v =
      if width == :unknown || width == "MXLEN"
        if !signed.empty?
          if unsigned_value > 0x7fff_ffff
            value_error("Don't know if value will be negative")
          else
            if unsigned_value > 0xffff_ffff
              value_error("Don't know if value will fit in literal")
            end
            unsigned_value
          end
        else
          if unsigned_value > 0xffff_ffff
            value_error("Don't know if value will fit in literal")
          end
          unsigned_value
        end
      else
        if unsigned_value.bit_length > width
          value_error("Value does not fit in literal")
        end
        if !signed.empty? && ((unsigned_value >> (width - 1)) == 1)
          if unsigned_value.bit_length > (width - 1)
            value_error("Value does not fit in literal")
          end
          -(2**width.to_i - unsigned_value)
        else
          unsigned_value
        end
      end

    @memo.value = v
  else
    @memo.value = unsigned_value
  end
end

#width(symtab) ⇒ Object 



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# File 'lib/idlc/ast.rb', line 7544

def width(symtab)
  return @memo.width unless @memo.width.nil?

  text_value_no_underscores = text_value.delete("_")

  case text_value_no_underscores
  when /^((MXLEN)|([0-9]+))?'(s?)([bodh]?)(.*)$/
    # verilog-style literal
    width = ::Regexp.last_match(1)
    if width.nil? || width == "MXLEN"
      if symtab.nil?
        width = :unknown
      else
        width = symtab.mxlen.nil? ? :unknown : symtab.mxlen
      end
    else
      width = width.to_i
    end
    @memo.width = width
  when /^0([bdx]?)([0-9a-fA-F]*)(s?)$/
    signed = ::Regexp.last_match(3)

    width = signed == "s" ? value(symtab).bit_length + 1 : value(symtab).bit_length
    width = 1 if width.zero? # happens when the literal is '0'

    @memo.width = width
  when /^([0-9]*)(s?)$/
    signed = ::Regexp.last_match(3)

    width = signed == "s" ? value(symtab).bit_length + 1 : value(symtab).bit_length
    width = 1 if width.zero? # happens when the literal is '0'

    @memo.width = width
  else
    internal_error "No match on int literal"
  end
end