From 37403f1139d58fbdda7db158aa49ae664a62a049 Mon Sep 17 00:00:00 2001
From: Torsten Ruger <torsten@villataika.fi>
Date: Fri, 26 Jun 2015 20:00:33 +0300
Subject: [PATCH] fix misunderstood mov usage

When moving a reference (pointer) to a register
one needs to ADD to the pc
i.e. one needs an add, not mov instruction
---
 lib/arm/instructions/move_instruction.rb | 21 ++++++++-------------
 test/arm/test_move.rb                    | 19 -------------------
 2 files changed, 8 insertions(+), 32 deletions(-)

diff --git a/lib/arm/instructions/move_instruction.rb b/lib/arm/instructions/move_instruction.rb
index fdf68314..4eda03e8 100644
--- a/lib/arm/instructions/move_instruction.rb
+++ b/lib/arm/instructions/move_instruction.rb
@@ -4,6 +4,9 @@ module Arm
 
     def initialize to , from , options = {}
       super(options)
+      if( from.is_a?(Symbol) and Register::RegisterReference.look_like_reg(from) )
+        from = Register::RegisterReference.new(from)
+      end
       @from = from
       @to = to
       raise "move must have from set #{inspect}" unless from
@@ -35,14 +38,6 @@ module Arm
       operand = @operand
       immediate = @immediate
       right = @from
-      if right.is_a?(Parfait::Object)
-        r_pos = right.position
-        # do pc relative addressing with the difference to the instuction
-        # 8 is for the funny pipeline adjustment (ie pc pointing to fetch and not execute)
-        right =  r_pos - self.position - 8
-        puts "Position #{r_pos} from #{self.position} = #{right}"
-        rn = :pc
-      end
       if (right.is_a?(Numeric))
         if (right.fits_u8?)
           # no shifting needed
@@ -79,7 +74,7 @@ module Arm
           # The way it _should_ be done
           # is to check that the first part is doabe with u8_with_rr AND leaves a u8 remainder
         end
-      elsif (right.is_a?(Symbol) or right.is_a?(::Register::RegisterReference))
+      elsif( right.is_a? Register::RegisterReference)
         operand = reg_code(right)
         immediate = 0                # ie not immediate is register
       else
@@ -92,10 +87,10 @@ module Arm
       val |= shift(reg_code(@to) ,            12)
       val |= shift(reg_code(rn) ,            12+4)
       val |= shift(@attributes[:update_status] , 12+4+4)#20
-      val |= shift(op_bit_code ,        12+4+4  +1)
-      val |= shift(immediate ,                  12+4+4  +1+4)
-      val |= shift(instuction_class ,   12+4+4  +1+4+1)
-      val |= shift(cond_bit_code ,      12+4+4  +1+4+1+2)
+      val |= shift(op_bit_code ,        12+4+4  + 1)
+      val |= shift(immediate ,          12+4+4  + 1+4)
+      val |= shift(instuction_class ,   12+4+4  + 1+4+1)
+      val |= shift(cond_bit_code ,      12+4+4  + 1+4+1+2)
       io.write_uint32 val
       # by now we have the extra add so assemble that
       if(@extra)
diff --git a/test/arm/test_move.rb b/test/arm/test_move.rb
index 32780001..63a3956b 100644
--- a/test/arm/test_move.rb
+++ b/test/arm/test_move.rb
@@ -32,23 +32,4 @@ class TestMoves < MiniTest::Test
     code = @machine.mvn  :r1,  5
     assert_code code , :mvn , [0x05,0x10,0xe0,0xe3] #e3 e0 10 05
   end
-  def test_constant_small # like test_mov
-    const = :harvey
-    const.set_position( 13 ) # 13 = 5 + 8 , 8 for the arm pipeline offset, gets subtracted
-    code = @machine.mov :r1 , 5
-    code.set_position(0)
-    #TODO check this in decompile
-    assert_code code , :mov , [0x05,0x10,0xa0,0xe3] #e3 ef 10 05
-  end
-  def test_constant_big # like test_mov_big
-    const = :harvey
-    const.set_position( 0x222 )
-    code = @machine.mov :r0 , 0x222
-    code.set_position(0)
-    begin  # mov 512(0x200) = e3 a0 0c 02    add 34(0x22) = e2 80 00 22
-      assert_code code , :mov , [ 0x02,0x0c,0xa0,0xe3 , 0x22,0x00,0x80,0xe2]
-    rescue Register::LinkException
-      retry
-    end
-  end
 end