fix .gitignore, Makefile and README.md for 2014/endoh

Unpack src.zip.

2014/endoh1/alpha.rb

@@ -0,0 +1,141 @@
+# alpha conversion (variable renaming)
+
+require_relative "ast-def"
+
+class ID
+  @@num = 0
+
+  def initialize(name)
+    @unified = nil
+    @name = "#{ name }:#{ @@num }"
+    @@num += 1
+  end
+
+  attr_reader :name, :unified
+
+  def inspect
+    if @unified
+      @unified.inspect
+    else
+      "#<#{ self.class }:#{ @name }>"
+    end
+  end
+
+  def unify(other)
+    if @unified
+      @unified.unify(other)
+    elsif other.term != self
+      @unified = other
+    end
+  end
+
+  def term
+    @unified ? @unified.term : self
+  end
+
+  def ==(other)
+    term.name == other.term.name
+  end
+
+  alias eql? ==
+
+  def hash
+    if @unified
+      @unified.hash
+    else
+      @name
+    end
+  end
+end 
+
+def merge(vars1, vars2)
+  vars1.each do |key, var|
+    if vars2[key] && vars2[key] != var
+      var.unify(vars2[key])
+    end
+  end
+  vars1.merge(vars2)
+end
+
+def check_opt_inc_dec(seq)
+  seq.each_cons(4) do |insn1, insn2, insn3, insn4|
+    next unless insn1.is_a?(IRead)
+    next unless insn2 == IPush[1]
+    next unless insn3 == IBinary[:+] || insn3 == IBinary[:-]
+    next unless insn4 == IWrite[insn1.var]
+    insn1.tmp.unify(insn4.tmp)
+  end
+
+  seq.each do |insn|
+    case insn
+    when IBranch, ILoop
+      check_opt_inc_dec(insn.s1)
+      check_opt_inc_dec(insn.s2)
+    end
+  end
+end
+
+def alpha(seq, vars)
+  nvars = vars.dup
+  seq.reverse_each do |insn|
+    case insn
+    when IRead
+      if insn.var
+        if insn.tmp
+          nvars[insn.var] ||= insn.tmp
+          nvars[insn.var].unify(insn.tmp)
+        else
+          insn.tmp = nvars[insn.var] ||= ID.new(insn.var)
+        end
+      end
+    when IWrite
+      if insn.var
+        if insn.tmp
+          nvars[insn.var] ||= insn.tmp
+          nvars[insn.var].unify(insn.tmp)
+        else
+          insn.tmp = nvars[insn.var]
+        end
+        nvars.delete(insn.var)
+      end
+    when IExit
+      nvars.clear
+    when IBranch
+      nvars1 = alpha(insn.s1, nvars)
+      nvars2 = alpha(insn.s2, nvars)
+      nvars = merge(nvars1, nvars2)
+    when ILoop
+      begin
+        nvars_back = nvars.dup
+        nvars1 = alpha(insn.s1, nvars)
+        nvars2 = alpha(insn.s1, alpha(insn.s2, nvars))
+        nvars = merge(nvars1, nvars2)
+        merge(nvars, nvars_back)
+      end until nvars.keys == nvars_back.keys
+    end
+  end
+  nvars
+end
+
+def rename(seq)
+  seq.each do |insn|
+    case insn
+    when IRead, IWrite
+      insn.tmp = ID.new(insn.var) if insn.var == "dummy"
+      insn.var.replace insn.tmp.term.name if insn.var
+    when IBranch, ILoop
+      rename(insn.s1)
+      rename(insn.s2)
+    end
+  end
+end
+
+if ARGV.size != 2
+  puts "usage: #$0 <seq1.txt> <seq2.txt>"
+else
+  seq = eval(File.read(ARGV[0]))
+  alpha(seq, {})
+  check_opt_inc_dec(seq)
+  rename(seq)
+  File.write(ARGV[1], seq.pretty_inspect)
+end