From cff622629704b1ba92415b1fd9079ae548957a60 Mon Sep 17 00:00:00 2001
From: Torsten Ruger <torsten@villataika.fi>
Date: Mon, 19 Mar 2018 21:19:26 +0530
Subject: [PATCH] own file for check

---
 lib/mom/instruction/check.rb       | 21 +++++++++++++++++++++
 lib/mom/instruction/truth_check.rb | 27 +++++++--------------------
 2 files changed, 28 insertions(+), 20 deletions(-)
 create mode 100644 lib/mom/instruction/check.rb

diff --git a/lib/mom/instruction/check.rb b/lib/mom/instruction/check.rb
new file mode 100644
index 00000000..447c4f4f
--- /dev/null
+++ b/lib/mom/instruction/check.rb
@@ -0,0 +1,21 @@
+module Mom
+
+  # A base class for conditions in MOM
+  # Checks (if in code, compare in assm) jump or not, depending
+  # The logic we choose is closer to the code logic (the asm is reversed)
+  # When we write an if, the true is the next code, so the Check logic is
+  # that if the check passes, no jump happens
+  # This means you need to pass the false label, where to jump to if the
+  # check does not pass
+  # Note: In assembler a branch on 0 does just that, it branches if the condition
+  #       is met. This means that the asm implementation is somewhat the reverse
+  #       of the Mom names. But it's easier to understand (imho)
+  class Check < Instruction
+    attr_reader :false_jump
+    def initialize(false_jump)
+      @false_jump = false_jump
+      raise "Jump target must be a label #{false_jump}" unless false_jump.is_a?(Label)
+    end
+  end
+
+end
diff --git a/lib/mom/instruction/truth_check.rb b/lib/mom/instruction/truth_check.rb
index f9a1c010..e3e81f6b 100644
--- a/lib/mom/instruction/truth_check.rb
+++ b/lib/mom/instruction/truth_check.rb
@@ -1,24 +1,6 @@
 module Mom
 
-  # A base class for conditions in MOM
-  # Checks (if in code, compare in assm) jump or not, depending
-  # The logic we choose is closer to the code logic (the asm is reversed)
-  # When we write an if, the true is the next code, so the Check logic is
-  # that if the check passes, no jump happens
-  # This means you need to pass the false label, where to jump to if the
-  # check does not pass
-  # Note: In assembler a branch on 0 does just that, it branches if the condition
-  #       is met. This means that the asm implementation is somewhat the reverse
-  #       of the Mom names. But it's easier to understand (imho)
-  class Check < Instruction
-    attr_reader :false_jump
-    def initialize(false_jump)
-      @false_jump = false_jump
-      raise "Jump target must be a label #{false_jump}" unless false_jump.is_a?(Label)
-    end
-  end
-
-  # The funny thing about the ruby truth is that is is anything but false or nil
+  # The funny thing about the ruby truth is that it is anything but false or nil
   #
   # To implement the normal ruby logic, we check for false or nil and jump
   # to the false branch. true_block follows implicitly
@@ -33,7 +15,12 @@ module Mom
     end
 
     def to_risc(compiler)
-      Risc::Label.new(self,"TruthCheck")
+      false_label = @false_jump.to_risc(compiler)
+      left = @condition.to_register(compiler,self)
+      false_load = SlotDefinition.new( FalseConstant.new , nil ).to_register(compiler,self)
+      left << false_load
+      left << Risc::IsSame.new(self , left.register , false_load.register , false_label)
+      left
     end
 
   end