Implement addition and subtraction

11 files changed, 119 insertions, 77 deletions

diff --git a/TODO b/TODO
index 2710951..c1c909f 100644
--- a/TODO
+++ b/TODO
@@ -17,6 +17,12 @@
 
 # Built-in
 
-Printi should print a sign for negative numbers.
+- Implement printc (with int argument).
+- Implement exit() as standalone function.
+
+# Register allocation
+
+- Temporary variables always use the same register, t0. Allocate registers for
+  temporaries.
 
 # Type analysis
diff --git a/lib/Language/Elna/AST.hs b/lib/Language/Elna/AST.hs
index 087c2fd..4861318 100644
--- a/lib/Language/Elna/AST.hs
+++ b/lib/Language/Elna/AST.hs
@@ -115,12 +115,12 @@ instance Show VariableDeclaration
     show (VariableDeclaration identifier typeExpression) =
         concat ["var ", show identifier, ": " <> show typeExpression, ";"]
 
-newtype Expression
+data Expression
     = LiteralExpression Literal
-{-    | VariableExpression VariableAccess
-    | NegationExpression Expression
     | SumExpression Expression Expression
     | SubtractionExpression Expression Expression
+{-    | VariableExpression VariableAccess
+    | NegationExpression Expression
     | ProductExpression Expression Expression
     | DivisionExpression Expression Expression -}
     deriving Eq
@@ -128,10 +128,10 @@ newtype Expression
 instance Show Expression
   where
     show (LiteralExpression literal) = show literal
-    {- show (VariableExpression variable) = show variable
-    show (NegationExpression negation) = '-' : show negation
     show (SumExpression lhs rhs) = concat [show lhs, " + ", show rhs]
     show (SubtractionExpression lhs rhs) = concat [show lhs, " - ", show rhs]
+    {- show (VariableExpression variable) = show variable
+    show (NegationExpression negation) = '-' : show negation
     show (ProductExpression lhs rhs) = concat [show lhs, " * ", show rhs]
     show (DivisionExpression lhs rhs) = concat [show lhs, " / ", show rhs] -}
 {-
diff --git a/lib/Language/Elna/CodeGenerator.hs b/lib/Language/Elna/CodeGenerator.hs
index 1a9151a..2e9b7a4 100644
--- a/lib/Language/Elna/CodeGenerator.hs
+++ b/lib/Language/Elna/CodeGenerator.hs
@@ -6,11 +6,12 @@ module Language.Elna.CodeGenerator
 import Data.ByteString (ByteString)
 import Data.HashMap.Strict (HashMap)
 import qualified Data.HashMap.Strict as HashMap
+import Data.Int (Int32)
 import Data.Vector (Vector)
 import qualified Data.Vector as Vector
 import qualified Data.Text.Encoding as Text.Encoding
 import Language.Elna.Location (Identifier(..))
-import Language.Elna.Intermediate (Operand(..), Quadruple(..))
+import Language.Elna.Intermediate (Operand(..), Quadruple(..), Variable(..))
 import qualified Language.Elna.Architecture.RiscV as RiscV
 import Language.Elna.SymbolTable (SymbolTable)
 import Data.Bits (Bits(..))
@@ -40,27 +41,12 @@ quadruple StartQuadruple = Vector.fromList
     , Instruction (RiscV.BaseInstruction RiscV.Store $ RiscV.S 4 RiscV.SW RiscV.SP RiscV.RA)
     , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.S0 RiscV.ADDI RiscV.SP 4)
     ]
-quadruple (ParameterQuadruple (IntOperand intValue))
-    = mappend go
-    $ Vector.fromList
+quadruple (ParameterQuadruple operand1) =
+    let (operandRegister, statements) = loadImmediateOrRegister operand1 RiscV.A0
+     in mappend statements $ Vector.fromList
         [ Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.SP RiscV.ADDI RiscV.SP (negate 4))
-        , Instruction (RiscV.BaseInstruction RiscV.Store $ RiscV.S 0 RiscV.SW RiscV.SP RiscV.A0)
+        , Instruction (RiscV.BaseInstruction RiscV.Store $ RiscV.S 0 RiscV.SW RiscV.SP operandRegister)
         ]
-  where
-    hi = intValue `shiftR` 12
-    lo = intValue
-    go
-        | intValue >= -2048
-        , intValue <= 2047 = Vector.singleton
-            $ Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.A0 RiscV.ADDI RiscV.A0 $ fromIntegral lo)
-        | intValue .&. 0x800 /= 0 = Vector.fromList
-            [ Instruction (RiscV.BaseInstruction RiscV.Lui $ RiscV.U RiscV.A0 $ fromIntegral $ succ hi)
-            , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.A0 RiscV.ADDI RiscV.A0 $ fromIntegral lo)
-            ]
-        | otherwise = Vector.fromList
-            [ Instruction (RiscV.BaseInstruction RiscV.Lui $ RiscV.U RiscV.A0 $ fromIntegral hi)
-            , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.A0 RiscV.ADDI RiscV.A0 $ fromIntegral lo)
-            ]
 quadruple (CallQuadruple callName numberOfArguments) = Vector.fromList
     [ Instruction (RiscV.CallInstruction callName)
     , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.SP RiscV.ADDI RiscV.SP (numberOfArguments * 4))
@@ -71,3 +57,39 @@ quadruple StopQuadruple = Vector.fromList
     , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I RiscV.SP RiscV.ADDI RiscV.SP 4)
     , Instruction (RiscV.BaseInstruction RiscV.Jalr $ RiscV.I RiscV.RA RiscV.JALR RiscV.Zero 0)
     ]
+quadruple (AddQuadruple operand1 operand2 (TempVariable _)) =
+    let (operandRegister1, statements1) = loadImmediateOrRegister operand1 RiscV.A0
+        (operandRegister2, statements2) = loadImmediateOrRegister operand2 RiscV.A1
+     in Vector.snoc (statements1 <> statements2)
+        $ Instruction
+        $ RiscV.BaseInstruction RiscV.Op
+        $ RiscV.R RiscV.T0 RiscV.ADD operandRegister1 operandRegister2 (RiscV.Funct7 0b0000000)
+quadruple (SubtractionQuadruple operand1 operand2 (TempVariable _)) =
+    let (operandRegister1, statements1) = loadImmediateOrRegister operand1 RiscV.A0
+        (operandRegister2, statements2) = loadImmediateOrRegister operand2 RiscV.A1
+     in Vector.snoc (statements1 <> statements2)
+        $ Instruction
+        $ RiscV.BaseInstruction RiscV.Op
+        $ RiscV.R RiscV.T0 RiscV.SUB operandRegister1 operandRegister2 (RiscV.Funct7 0b0100000)
+
+loadImmediateOrRegister :: Operand -> RiscV.XRegister -> (RiscV.XRegister, Vector Statement)
+loadImmediateOrRegister (IntOperand intValue) targetRegister =
+    (targetRegister, lui intValue targetRegister)
+loadImmediateOrRegister (VariableOperand _) _ = (RiscV.T0, Vector.empty)
+
+lui :: Int32 -> RiscV.XRegister -> Vector Statement
+lui intValue targetRegister
+    | intValue >= -2048
+    , intValue <= 2047 = Vector.singleton
+        $ Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I targetRegister RiscV.ADDI RiscV.Zero lo)
+    | intValue .&. 0x800 /= 0 = Vector.fromList
+        [ Instruction (RiscV.BaseInstruction RiscV.Lui $ RiscV.U targetRegister $ fromIntegral $ succ hi)
+        , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I targetRegister RiscV.ADDI targetRegister lo)
+        ]
+    | otherwise = Vector.fromList
+        [ Instruction (RiscV.BaseInstruction RiscV.Lui $ RiscV.U targetRegister $ fromIntegral hi)
+        , Instruction (RiscV.BaseInstruction RiscV.OpImm $ RiscV.I targetRegister RiscV.ADDI targetRegister lo)
+        ]
+  where
+    hi = intValue `shiftR` 12
+    lo = fromIntegral intValue
diff --git a/lib/Language/Elna/Intermediate.hs b/lib/Language/Elna/Intermediate.hs
index 35f5ad2..d535b6a 100644
--- a/lib/Language/Elna/Intermediate.hs
+++ b/lib/Language/Elna/Intermediate.hs
@@ -1,8 +1,8 @@
 module Language.Elna.Intermediate
     ( Operand(..)
     , Quadruple(..)
-    {- , Label(..)
-    , Variable(..) -}
+    {- , Label(..) -}
+    , Variable(..)
     , intermediate
     ) where
 
@@ -17,12 +17,20 @@ import Data.Text (Text)
 import qualified Language.Elna.AST as AST
 import Language.Elna.SymbolTable (SymbolTable{-, Info(..) -})
 import Data.Foldable (Foldable(..))
-import Control.Monad.Trans.State (State, runState)
+import Control.Monad.Trans.State (State, get, modify', runState)
 import Data.Maybe (catMaybes)
 
-newtype Operand
+newtype Variable = TempVariable Word32 -- | Variable Text
+    deriving Eq
+
+instance Show Variable
+  where
+    -- show (Variable variable) = '$' : Text.unpack variable
+    show (TempVariable variable) = '$' : show variable
+
+data Operand
     = IntOperand Int32
-    -- | VariableOperand Variable
+    | VariableOperand Variable
     deriving (Eq, Show)
 
 data Quadruple
@@ -30,12 +38,12 @@ data Quadruple
     | StopQuadruple
     | ParameterQuadruple Operand
     | CallQuadruple Text Word32
+    | AddQuadruple Operand Operand Variable
+    | SubtractionQuadruple Operand Operand Variable
     {-| GoToQuadruple Label
     | AssignQuadruple Operand Variable
     | ArrayQuadruple Variable Operand Variable
     | ArrayAssignQuadruple Operand Operand Variable
-    | AddQuadruple Operand Operand Variable
-    | SubtractionQuadruple Operand Operand Variable
     | ProductQuadruple Operand Operand Variable
     | DivisionQuadruple Operand Operand Variable
     | NegationQuadruple Operand Variable
@@ -142,6 +150,12 @@ statement localTable (AST.WhileStatement whileCondition whileStatement) = do
 statement localTable (AST.CompoundStatement statements) =
     fold <$> traverse (statement localTable) statements -}
 
+createTemporary :: Intermediate Variable
+createTemporary = do
+    currentCounter <- Intermediate get
+    Intermediate $ modify' (+ 1)
+    pure $ TempVariable currentCounter
+
 {-
 import Language.Elna.Types (Type(..))
 import qualified Language.Elna.SymbolTable as SymbolTable
@@ -171,16 +185,6 @@ createLabel = do
         { labelCounter = getField @"labelCounter" generator + 1
         }
 
-createTemporary :: Intermediate Variable
-createTemporary = do
-    currentCounter <- Intermediate $ gets temporaryCounter
-    Intermediate $ modify' modifier
-    pure $ TempVariable currentCounter
-  where
-    modifier generator = generator
-        { temporaryCounter = getField @"temporaryCounter" generator + 1
-        }
-
 condition
     :: SymbolTable
     -> AST.Condition
@@ -257,8 +261,11 @@ variableType (AST.ArrayAccess arrayAccess' _) symbolTable =
     variableType arrayAccess' symbolTable
 -}
 expression :: SymbolTable -> AST.Expression -> Intermediate (Operand, Vector Quadruple)
-expression _localTable = \case
+expression localTable = \case
     (AST.LiteralExpression literal') -> pure (literal literal', mempty)
+    (AST.SumExpression lhs rhs) -> binaryExpression AddQuadruple lhs rhs
+    (AST.SubtractionExpression lhs rhs) ->
+        binaryExpression SubtractionQuadruple lhs rhs
 {-    (AST.VariableExpression variableExpression) -> do
         let variableType' = variableType variableExpression localTable
         variableAccess' <- variableAccess localTable variableExpression Nothing variableType' mempty
@@ -280,13 +287,10 @@ expression _localTable = \case
             ( VariableOperand tempVariable
             , Vector.snoc statements negationQuadruple
             )
-    (AST.SumExpression lhs rhs) -> binaryExpression AddQuadruple lhs rhs
-    (AST.SubtractionExpression lhs rhs) ->
-        binaryExpression SubtractionQuadruple lhs rhs
     (AST.ProductExpression lhs rhs) ->
         binaryExpression ProductQuadruple lhs rhs
     (AST.DivisionExpression lhs rhs) ->
-        binaryExpression DivisionQuadruple lhs rhs
+        binaryExpression DivisionQuadruple lhs rhs -}
   where
     binaryExpression f lhs rhs = do
         (lhsOperand, lhsStatements) <- expression localTable lhs
@@ -298,14 +302,6 @@ expression _localTable = \case
             , Vector.snoc (lhsStatements <> rhsStatements) newQuadruple
             )
 
-data Variable = Variable Text | TempVariable Int32
-    deriving Eq
-
-instance Show Variable
-  where
-    show (Variable variable) = '$' : Text.unpack variable
-    show (TempVariable variable) = '$' : show variable
--}
 literal :: AST.Literal -> Operand
 literal (AST.IntegerLiteral integer) = IntOperand integer
 {-literal (AST.HexadecimalLiteral integer) = IntOperand integer
diff --git a/lib/Language/Elna/NameAnalysis.hs b/lib/Language/Elna/NameAnalysis.hs
index 6cb2f5c..10045e9 100644
--- a/lib/Language/Elna/NameAnalysis.hs
+++ b/lib/Language/Elna/NameAnalysis.hs
@@ -136,16 +136,16 @@ checkSymbol globalTable identifier
 
 expression :: SymbolTable -> AST.Expression -> NameAnalysis ()
 expression _ (AST.LiteralExpression _) = pure ()
-{- expression globalTable (AST.VariableExpression variableExpression) =
-    variableAccess globalTable variableExpression
-expression globalTable (AST.NegationExpression negation) =
-    expression globalTable negation
 expression globalTable (AST.SumExpression lhs rhs)
     = expression globalTable lhs
     >> expression globalTable rhs
 expression globalTable (AST.SubtractionExpression lhs rhs)
     = expression globalTable lhs
     >> expression globalTable rhs
+{- expression globalTable (AST.VariableExpression variableExpression) =
+    variableAccess globalTable variableExpression
+expression globalTable (AST.NegationExpression negation) =
+    expression globalTable negation
 expression globalTable (AST.ProductExpression lhs rhs)
     = expression globalTable lhs
     >> expression globalTable rhs
diff --git a/lib/Language/Elna/Parser.hs b/lib/Language/Elna/Parser.hs
index 5583601..3c98fff 100644
--- a/lib/Language/Elna/Parser.hs
+++ b/lib/Language/Elna/Parser.hs
@@ -4,7 +4,7 @@ module Language.Elna.Parser
     ) where
 
 import Control.Monad (void)
-import Control.Monad.Combinators.Expr ({-Operator(..), -} makeExprParser)
+import Control.Monad.Combinators.Expr (Operator(..), makeExprParser)
 import Data.Text (Text)
 import qualified Data.Text as Text
 import Data.Void (Void)
@@ -69,38 +69,38 @@ termP = choice
     , LiteralExpression <$> literalP
     -- , VariableExpression <$> variableAccessP
     ]
-{-
-variableAccessP :: Parser VariableAccess
-variableAccessP = do
-    identifier <- identifierP
-    indices <- many $ bracketsP expressionP
-    pure $ foldr (flip ArrayAccess) (VariableAccess identifier) indices
 
 operatorTable :: [[Operator Parser Expression]]
 operatorTable =
-    [ unaryOperator
+    [{- unaryOperator
     , factorOperator
-    , termOperator
+    ,-} termOperator
     ]
   where
-    unaryOperator =
+    {- unaryOperator =
         [ prefix "-" NegationExpression
         , prefix "+" id
         ]
     factorOperator =
         [ binary "*" ProductExpression
         , binary "/" DivisionExpression
-        ]
+        ] -}
     termOperator =
         [ binary "+" SumExpression
         , binary "-" SubtractionExpression
         ]
-    prefix name f = Prefix (f <$ symbol name)
+    -- prefix name f = Prefix (f <$ symbol name)
     binary name f = InfixL (f <$ symbol name)
--}
+
 expressionP :: Parser Expression
-expressionP = makeExprParser termP [] -- operatorTable
+expressionP = makeExprParser termP operatorTable
 {-
+variableAccessP :: Parser VariableAccess
+variableAccessP = do
+    identifier <- identifierP
+    indices <- many $ bracketsP expressionP
+    pure $ foldr (flip ArrayAccess) (VariableAccess identifier) indices
+
 conditionP :: Parser Condition
 conditionP = do
     lhs <- expressionP
@@ -204,8 +204,8 @@ statementP
         <$> variableAccessP
         <* symbol ":="
         <*> expressionP
-        <* semicolonP
--}
+        <* semicolonP -}
+
 variableDeclarationP :: Parser VariableDeclaration
 variableDeclarationP = VariableDeclaration
     <$> (symbol "var" *> identifierP)
diff --git a/tests/expectations/print_subtraction.txt b/tests/expectations/print_subtraction.txt
new file mode 100644
index 0000000..de71f88
--- /dev/null
+++ b/tests/expectations/print_subtraction.txt
@@ -0,0 +1 @@
+-8
diff --git a/tests/expectations/print_sum.txt b/tests/expectations/print_sum.txt
new file mode 100644
index 0000000..3c03207
--- /dev/null
+++ b/tests/expectations/print_sum.txt
@@ -0,0 +1 @@
+18
diff --git a/tests/vm/print_subtraction.elna b/tests/vm/print_subtraction.elna
new file mode 100644
index 0000000..c5b09a2
--- /dev/null
+++ b/tests/vm/print_subtraction.elna
@@ -0,0 +1,3 @@
+proc main() {
+  printi(5 - 13);
+}
diff --git a/tests/vm/print_sum.elna b/tests/vm/print_sum.elna
new file mode 100644
index 0000000..8ad98d6
--- /dev/null
+++ b/tests/vm/print_sum.elna
@@ -0,0 +1,3 @@
+proc main() {
+  printi(5 + 13);
+}
diff --git a/tools/builtin.s b/tools/builtin.s
index 7b14d95..ecea15b 100644
--- a/tools/builtin.s
+++ b/tools/builtin.s
@@ -18,10 +18,16 @@ printi:
     # t1 - Constant 10.
     # a1 - Local buffer.
     # t2 - Current character.
+    # t3 - Whether the number is negative.
     lw t0, 0(s0)
     addi t1, zero, 10
     addi a1, s0, -2
 
+    addi t3, zero, 0
+    bge t0, zero, .digit10
+    addi t3, zero, 1
+    sub t0, zero, t0
+
 .digit10:
     rem t2, t0, t1
     addi t2, t2, '0'
@@ -30,8 +36,12 @@ printi:
     addi a1, a1, -1
     bne zero, t0, .digit10
 
-    ecall
+    beq zero, t3, .write_call
+    addi t2, zero, '-'
+    sb t2, 0(a1)
+    addi a1, a1, -1
 
+.write_call:
     addi a0, zero, 1
     addi a1, a1, 1
     sub a2, s0, a1