Implement division

TODO

@@ -17,8 +17,9 @@
 
 # Register allocation
 
-- Temporary variables always use the same register, t0. Allocate registers for
+- Each temporary variales gets a tn register where n is the variable index. If
-  temporaries.
+  there more variables the allocation will fail with out of bounds runtime
+  error. Implement spill over.
 
 # Prarsing and abstract syntax tree
 
@@ -27,3 +28,4 @@
 # Other
 
 - Type analysis.
+- Generate call a to _divide_by_zero_error on RiscV.

lib/Language/Elna/Backend/Allocator.hs

@@ -12,7 +12,7 @@ import Language.Elna.Location (Identifier(..))
 newtype Store r = Store r
 
 newtype MachineConfiguration r = MachineConfiguration
-    { temporaryRegister :: r
+    { temporaryRegisters :: [r]
     }
 
 allocate
@@ -30,14 +30,29 @@ allocate MachineConfiguration{..} = fmap function
     quadruple (ParameterQuadruple operand1) =
         ParameterQuadruple (operand operand1)
     quadruple (CallQuadruple name count) = CallQuadruple name count
-    quadruple (AddQuadruple operand1 operand2 _) =
+    quadruple (AddQuadruple operand1 operand2 (TempVariable index))
-        AddQuadruple (operand operand1) (operand operand2) (Store temporaryRegister)
+        = AddQuadruple (operand operand1) (operand operand2)
-    quadruple (SubtractionQuadruple operand1 operand2 _) =
+        $ Store
-        SubtractionQuadruple (operand operand1) (operand operand2) (Store temporaryRegister)
+        $ temporaryRegisters !! fromIntegral index
-    quadruple (NegationQuadruple operand1 _) =
+    quadruple (SubtractionQuadruple operand1 operand2 (TempVariable index))
-        NegationQuadruple (operand operand1) (Store temporaryRegister)
+        = SubtractionQuadruple (operand operand1) (operand operand2)
-    quadruple (ProductQuadruple operand1 operand2 _) =
+        $ Store
-        ProductQuadruple (operand operand1) (operand operand2) (Store temporaryRegister)
+        $ temporaryRegisters !! fromIntegral index
+    quadruple (NegationQuadruple operand1 (TempVariable index))
+        = NegationQuadruple (operand operand1)
+        $ Store
+        $ temporaryRegisters !! fromIntegral index
+    quadruple (ProductQuadruple operand1 operand2 (TempVariable index))
+        = ProductQuadruple (operand operand1) (operand operand2)
+        $ Store
+        $ temporaryRegisters !! fromIntegral index
+    quadruple (DivisionQuadruple operand1 operand2 (TempVariable index))
+        = DivisionQuadruple (operand operand1) (operand operand2)
+        $ Store
+        $ temporaryRegisters !! fromIntegral index
     operand :: Operand Variable -> Operand (Store r)
     operand (IntOperand x) = IntOperand x
-    operand (VariableOperand _) = VariableOperand (Store temporaryRegister)
+    operand (VariableOperand (TempVariable index))
+        = VariableOperand
+        $ Store
+        $ temporaryRegisters !! fromIntegral index

lib/Language/Elna/Backend/Intermediate.hs

@@ -31,11 +31,11 @@ data Quadruple v
     | SubtractionQuadruple (Operand v) (Operand v) v
     | NegationQuadruple (Operand v) v
     | ProductQuadruple (Operand v) (Operand v) v
+    | DivisionQuadruple (Operand v) (Operand v) v
     {-| GoToQuadruple Label
     | AssignQuadruple Operand Variable
     | ArrayQuadruple Variable Operand Variable
     | ArrayAssignQuadruple Operand Operand Variable
-    | DivisionQuadruple Operand Operand Variable
     | EqualQuadruple Operand Operand Label
     | NonEqualQuadruple Operand Operand Label
     | LessQuadruple Operand Operand Label

lib/Language/Elna/Frontend/AST.hs

@@ -119,8 +119,8 @@ data Expression
     | SubtractionExpression Expression Expression
     | NegationExpression Expression
     | ProductExpression Expression Expression
-{-    | VariableExpression VariableAccess
+    | DivisionExpression Expression Expression
-    | DivisionExpression Expression Expression -}
+    -- | VariableExpression VariableAccess
     deriving Eq
 
 instance Show Expression
@@ -130,8 +130,8 @@ instance Show Expression
     show (SubtractionExpression lhs rhs) = concat [show lhs, " - ", show rhs]
     show (NegationExpression negation) = '-' : show negation
     show (ProductExpression lhs rhs) = concat [show lhs, " * ", show rhs]
-    {- show (VariableExpression variable) = show variable
+    show (DivisionExpression lhs rhs) = concat [show lhs, " / ", show rhs]
-    show (DivisionExpression lhs rhs) = concat [show lhs, " / ", show rhs] -}
+    -- show (VariableExpression variable) = show variable
 {-
 data VariableAccess
     = VariableAccess Identifier

lib/Language/Elna/Frontend/NameAnalysis.hs

@@ -147,11 +147,11 @@ expression globalTable (AST.NegationExpression negation) =
 expression globalTable (AST.ProductExpression lhs rhs)
     = expression globalTable lhs
     >> expression globalTable rhs
-{- expression globalTable (AST.VariableExpression variableExpression) =
-    variableAccess globalTable variableExpression
 expression globalTable (AST.DivisionExpression lhs rhs)
     = expression globalTable lhs
     >> expression globalTable rhs
+{- expression globalTable (AST.VariableExpression variableExpression) =
+    variableAccess globalTable variableExpression
 -}
 statement :: SymbolTable -> AST.Statement -> NameAnalysis ()
 statement _ AST.EmptyStatement = pure ()

lib/Language/Elna/Frontend/Parser.hs

@@ -80,7 +80,7 @@ operatorTable =
         ]
     factorOperator =
         [ binary "*" ProductExpression
-        -- , binary "/" DivisionExpression
+        , binary "/" DivisionExpression
         ]
     termOperator =
         [ binary "+" SumExpression

lib/Language/Elna/Glue.hs

@@ -235,6 +235,8 @@ expression localTable = \case
             )
     (AST.ProductExpression lhs rhs) ->
         binaryExpression ProductQuadruple lhs rhs
+    (AST.DivisionExpression lhs rhs) ->
+        binaryExpression DivisionQuadruple lhs rhs
 {-    (AST.VariableExpression variableExpression) -> do
         let variableType' = variableType variableExpression localTable
         variableAccess' <- variableAccess localTable variableExpression Nothing variableType' mempty
@@ -247,9 +249,7 @@ expression localTable = \case
                 pure
                     ( VariableOperand arrayAddress
                     , Vector.snoc statements arrayStatement
-                    )
+                    ) -}
-    (AST.DivisionExpression lhs rhs) ->
-        binaryExpression DivisionQuadruple lhs rhs -}
   where
     binaryExpression f lhs rhs = do
         (lhsOperand, lhsStatements) <- expression localTable lhs

lib/Language/Elna/RiscV/CodeGenerator.hs

@@ -29,7 +29,15 @@ data Statement
 
 riscVConfiguration :: MachineConfiguration RiscV.XRegister
 riscVConfiguration = MachineConfiguration
-    { temporaryRegister = RiscV.T0
+    { temporaryRegisters =
+        [ RiscV.T0
+        , RiscV.T1
+        , RiscV.T2
+        , RiscV.T3
+        , RiscV.T4
+        , RiscV.T5
+        , RiscV.T6
+        ]
     }
 
 type RiscVStore = Store RiscV.XRegister
@@ -158,6 +166,35 @@ quadruple (ProductQuadruple operand1 operand2 (Store register))
             $ RiscV.BaseInstruction RiscV.Op
             $ RiscV.R register RiscV.MUL register operandRegister
             $ RiscV.Funct7 0b0000001
+quadruple (DivisionQuadruple operand1 operand2 (Store register))
+    | IntOperand immediateOperand1 <- operand1
+    , IntOperand immediateOperand2 <- operand2 =
+        lui (quot immediateOperand1 immediateOperand2) register
+    | VariableOperand variableOperand1 <- operand1
+    , VariableOperand variableOperand2 <- operand2 =
+        let Store operandRegister1 = variableOperand1
+            Store operandRegister2 = variableOperand2
+        in pure $ Instruction
+            $ RiscV.BaseInstruction RiscV.Op
+            $ RiscV.R register RiscV.DIV operandRegister1 operandRegister2 (RiscV.Funct7 0b0000001)
+    | VariableOperand variableOperand1 <- operand1
+    , IntOperand immediateOperand2 <- operand2 =
+        let statements2 = lui immediateOperand2 register
+            Store operandRegister1 = variableOperand1
+        in Vector.snoc statements2
+            $ Instruction
+            $ RiscV.BaseInstruction RiscV.Op
+            $ RiscV.R register RiscV.DIV operandRegister1 register
+            $ RiscV.Funct7 0b0000001
+    | IntOperand immediateOperand1 <- operand1
+    , VariableOperand variableOperand2 <- operand2 =
+        let statements1 = lui immediateOperand1 register
+            Store operandRegister2 = variableOperand2
+        in Vector.snoc statements1
+            $ Instruction
+            $ RiscV.BaseInstruction RiscV.Op
+            $ RiscV.R register RiscV.DIV register operandRegister2
+            $ RiscV.Funct7 0b0000001
 
 loadImmediateOrRegister :: RiscVOperand -> RiscV.XRegister -> (RiscV.XRegister, Vector Statement)
 loadImmediateOrRegister (IntOperand intValue) targetRegister =

tests/expectations/add_products.txt

@@ -0,0 +1 @@
+38

tests/expectations/printi_quotient.txt

@@ -0,0 +1 @@
+2

tests/vm/add_products.elna

@@ -0,0 +1,3 @@
+proc main() {
+  printi(2 * 3 + 4 * 8);
+}

tests/vm/printi_divide_by_zero.elna

@@ -0,0 +1,3 @@
+proc main() {
+  printi(4 / (2 - 2));
+}

tests/vm/printi_quotient.elna

@@ -0,0 +1,3 @@
+proc main() {
+  printi(4 / 2);
+}

tools/builtin.s

@@ -7,6 +7,9 @@
 .global exit
 .type exit, @function
 
+.global _divide_by_zero_error
+.type _divide_by_zero_error, @function
+
 .global _start
 .type _start, @function
 
@@ -51,7 +54,7 @@ printi:
     addi a0, zero, 1
     addi a1, a1, 1
     sub a2, s0, a1
-    addi a7, zero, 64
+    addi a7, zero, 64 # write
     ecall
 
     lw s0, 0(sp)
@@ -74,7 +77,7 @@ printc:
     addi a0, zero, 1
     addi a1, s0, -2
     addi a2, zero, 2
-    addi a7, zero, 64
+    addi a7, zero, 64 # write
     ecall
 
     lw s0, 0(sp)
@@ -84,10 +87,19 @@ printc:
 
 exit:
     addi a0, zero, 0
-    addi a7, zero, 93
+    addi a7, zero, 93 # exit
     ecall
     # ret
 
+_divide_by_zero_error:
+    addi a7, zero, 172 # getpid
+    ecall
+
+    addi a1, zero, 8 # SIGFPE
+    addi a7, zero, 129 # kill
+    ecall
+    ret
+
 _start:
     call main
     call exit