From d6108e7b3a1ece42669e12269376c2c3bf01bfed Mon Sep 17 00:00:00 2001
From: Torsten Ruger <torsten@villataika.fi>
Date: Sun, 8 Nov 2015 15:15:55 +0200
Subject: [PATCH] fix interpreter overflow issue

flag set for bigness, result reduced
tests for + and *
fixed fibs tests
---
 lib/interpreter/interpreter.rb                | 10 ++++--
 stash/fibo_times.ruby                         |  3 +-
 test/compiler/fragments/test_while_fibo.rb    | 18 +++++-----
 test/interpreter/helper.rb                    |  5 +++
 test/interpreter/test_all.rb                  |  3 +-
 test/interpreter/test_if.rb                   |  2 +-
 .../interpreter/{test_ops.rb => test_mult.rb} | 30 +++++++---------
 test/interpreter/test_plus.rb                 | 35 +++++++++++++++++++
 8 files changed, 73 insertions(+), 33 deletions(-)
 rename test/interpreter/{test_ops.rb => test_mult.rb} (52%)
 create mode 100644 test/interpreter/test_plus.rb

diff --git a/lib/interpreter/interpreter.rb b/lib/interpreter/interpreter.rb
index 891675fe..1f6d0e77 100644
--- a/lib/interpreter/interpreter.rb
+++ b/lib/interpreter/interpreter.rb
@@ -1,5 +1,6 @@
 
 require_relative "eventable"
+require 'bigdecimal'
 
 module Interpreter
   class Interpreter
@@ -174,10 +175,10 @@ module Interpreter
     end
 
     def execute_OperatorInstruction
-      log.debug @instruction
       left = get_register(@instruction.left)
       rr = @instruction.right
       right = get_register(rr)
+      @flags[:overflow] = false
       case @instruction.operator.to_s
       when "+"
         result = left + right
@@ -193,8 +194,11 @@ module Interpreter
       else
         raise "unimplemented  '#{@instruction.operator}' #{@instruction}"
       end
-      ## result not over 2**62  => overflow
-      log.debug "#{@instruction} == #{result}   (#{left}|#{right})"
+      if( result.is_a? Bignum)
+        @flags[:overflow] = true
+        result = result % 2**62
+      end
+      log.debug "#{@instruction} == #{result}(#{result.class})   (#{left}|#{right})"
       right = set_register(@instruction.left , result)
       true
     end
diff --git a/stash/fibo_times.ruby b/stash/fibo_times.ruby
index f6ced695..b06f34c0 100644
--- a/stash/fibo_times.ruby
+++ b/stash/fibo_times.ruby
@@ -10,4 +10,5 @@ def fibonaccit(n)
 end
 
 #1000000.times {fibonaccit( 30 )}
-puts fibonaccit 100
+#10.times {|i| puts fibonaccit(i+90).class}
+puts fibonaccit 90
diff --git a/test/compiler/fragments/test_while_fibo.rb b/test/compiler/fragments/test_while_fibo.rb
index aaba5442..8ff769fd 100644
--- a/test/compiler/fragments/test_while_fibo.rb
+++ b/test/compiler/fragments/test_while_fibo.rb
@@ -28,17 +28,17 @@ HERE
     @string_input.sub!( "100" , num.to_s )
   end
 
-  def test_while_fibo100
-    fibo 100
-    @length = 2345
-    #TODO bug, int max is 92 ruby converts to biginteger.
-    check_return  354224848179261915075
+  def test_while_fibo94
+    fibo 91
+    @length = 2138
+    # this is not the correct fibo, just what comes from wrapping (smaller than below)
+    check_return 48360591948142405
   end
 
-  def test_while_fibo92
-    fibo 92
-    @length = 2161
-    check_return  7540113804746346429
+  def test_while_fibo90
+    fibo 90
+    @length = 2115
+    check_return 2880067194370816120
   end
 
 end
diff --git a/test/interpreter/helper.rb b/test/interpreter/helper.rb
index a17ce153..1d871037 100644
--- a/test/interpreter/helper.rb
+++ b/test/interpreter/helper.rb
@@ -21,6 +21,11 @@ module Ticker
     end
   end
 
+  def check_return val
+    assert_equal Parfait::Message , @interpreter.get_register(:r0).class
+    assert_equal val , @interpreter.get_register(:r0).return_value
+  end
+
   def ticks num
     last = nil
     num.times do
diff --git a/test/interpreter/test_all.rb b/test/interpreter/test_all.rb
index 1e826c92..332f49ce 100644
--- a/test/interpreter/test_all.rb
+++ b/test/interpreter/test_all.rb
@@ -1,4 +1,5 @@
 require_relative "test_add"
 require_relative "test_if"
 require_relative "test_puts"
-require_relative "test_ops"
+require_relative "test_plus"
+require_relative "test_mult"
diff --git a/test/interpreter/test_if.rb b/test/interpreter/test_if.rb
index 0c19614a..7f0e1723 100644
--- a/test/interpreter/test_if.rb
+++ b/test/interpreter/test_if.rb
@@ -1,6 +1,6 @@
 require_relative "helper"
 
-class AddTest < MiniTest::Test
+class IfTest < MiniTest::Test
   include Ticker
 
   def setup
diff --git a/test/interpreter/test_ops.rb b/test/interpreter/test_mult.rb
similarity index 52%
rename from test/interpreter/test_ops.rb
rename to test/interpreter/test_mult.rb
index aec8aa9e..09f08bae 100644
--- a/test/interpreter/test_ops.rb
+++ b/test/interpreter/test_mult.rb
@@ -1,6 +1,6 @@
 require_relative "helper"
 
-class AddTest < MiniTest::Test
+class MultTest < MiniTest::Test
   include Ticker
   include AST::Sexp
 
@@ -8,35 +8,29 @@ class AddTest < MiniTest::Test
     @string_input = <<HERE
 class Object
   int main()
-    return 5 + 10
+    return #{2**31} * #{2**31}
   end
 end
 HERE
     super
   end
 
-  def test_add
-    #show_ticks # get output of what is
-    check_chain ["Branch","Label","LoadConstant","GetSlot","SetSlot",
-     "LoadConstant","SetSlot","FunctionCall","Label","LoadConstant",
-     "LoadConstant","OperatorInstruction","SetSlot","Label","FunctionReturn",
-     "RegisterTransfer","Syscall","NilClass"]
-  end
-
   def test_mult
-    @string_input = <<HERE
-class Object
-  int main()
-    return 5 * 10
-  end
-end
-HERE
-    setup
     #show_ticks # get output of what is
     check_chain ["Branch","Label","LoadConstant","GetSlot","SetSlot",
      "LoadConstant","SetSlot","FunctionCall","Label","LoadConstant",
      "LoadConstant","OperatorInstruction","SetSlot","Label","FunctionReturn",
      "RegisterTransfer","Syscall","NilClass"]
+     check_return 0
+  end
+  def test_overflow
+    ticks( 12 )
+    assert @interpreter.flags[:overflow]
+  end
+
+  def test_zero
+    ticks( 12 )
+    assert @interpreter.flags[:zero]
   end
 
 end
diff --git a/test/interpreter/test_plus.rb b/test/interpreter/test_plus.rb
new file mode 100644
index 00000000..ff31d0d3
--- /dev/null
+++ b/test/interpreter/test_plus.rb
@@ -0,0 +1,35 @@
+require_relative "helper"
+
+class PlusTest < MiniTest::Test
+  include Ticker
+
+  def setup
+    @string_input = <<HERE
+class Object
+  int main()
+    return #{2**62 - 1} + 1
+  end
+end
+HERE
+    super
+  end
+
+  def test_add
+    #show_ticks # get output of what is
+    check_chain ["Branch","Label","LoadConstant","GetSlot","SetSlot",
+     "LoadConstant","SetSlot","FunctionCall","Label","LoadConstant",
+     "LoadConstant","OperatorInstruction","SetSlot","Label","FunctionReturn",
+     "RegisterTransfer","Syscall","NilClass"]
+    check_return 0
+  end
+
+  def test_overflow
+    ticks( 12 )
+    assert @interpreter.flags[:overflow]
+  end
+
+  def test_zero
+    ticks( 12 )
+    assert @interpreter.flags[:zero]
+  end
+end