Assume boxed regions

effekt-lang · Oct 22, 2024 · fc4c49d · fc4c49d
1 parent 97538fd
commit fc4c49d
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Showing 5 changed files with 21 additions and 44 deletions.
diff --git a/effekt/shared/src/main/scala/effekt/generator/llvm/Transformer.scala b/effekt/shared/src/main/scala/effekt/generator/llvm/Transformer.scala
@@ -198,31 +198,17 @@ object Transformer {
       case machine.Var(ref @ machine.Variable(name, machine.Type.Reference(tpe)), init, retType, rest) =>
         val environment = List(init)
         val returnAddressName = freshName("returnAddress")
-        retType match {
-          case Some(retType) =>
-            val returnType = transform(retType)
-            val returnValue = freshName("returnValue")
-            val parameters = List(Parameter(returnType, returnValue))
-            defineLabel(returnAddressName, parameters) {
-              emit(Comment(s"var $name / return address"))
-              popEnvironmentFrom(getStack(), environment)
-              eraseValue(init)
-              val nextReturn = LocalReference(returnAddressType, freshName("returnAddress"))
-              popReturnAddressFrom(getStack(), nextReturn.name)
-              emit(callLabel(nextReturn, List(LocalReference(returnType, returnValue))))
-              RetVoid()
-            }
-
-          case None =>
-            defineFunction(returnAddressName, List(Parameter(stackType, "stack"))) {
-              emit(Comment(s"region var $name / return address"))
-              popEnvironmentFrom(getStack(), environment)
-              eraseValue(init)
-              val nextReturn = LocalReference(returnAddressType, freshName("returnAddress"))
-              popReturnAddressFrom(getStack(), nextReturn.name)
-              emit(Call("", Ccc(), VoidType(), nextReturn, List(getStack())))
-              RetVoid()
-            }
+        val returnType = transform(retType)
+        val returnValue = freshName("returnValue")
+        val parameters = List(Parameter(returnType, returnValue))
+        defineLabel(returnAddressName, parameters) {
+          emit(Comment(s"var $name / return address"))
+          popEnvironmentFrom(getStack(), environment)
+          eraseValue(init)
+          val nextReturn = LocalReference(returnAddressType, freshName("returnAddress"))
+          popReturnAddressFrom(getStack(), nextReturn.name)
+          emit(callLabel(nextReturn, List(LocalReference(returnType, returnValue))))
+          RetVoid()
         }
 
         val sharerName = freshName("sharer");
@@ -349,13 +335,9 @@ object Transformer {
         emit(callLabel(returnAddress, values.map(transform)))
         RetVoid()
 
-      case machine.Reset(prompt, frame, isRegion, rest) =>
+      case machine.Reset(prompt, frame, rest) =>
         emit(Comment(s"Reset ${prompt.name}"))
 
-        if (isRegion) {
-          pushReturnAddressOnto(getStack(), "nop", shareFrames.name, eraseFrames.name)
-        }
-
         val newStack = LocalReference(stackType, freshName("stack"))
         emit(Call(newStack.name, Ccc(), stackType, reset, List(getStack())));
         setStack(newStack)
@@ -375,11 +357,6 @@ object Transformer {
           val nextStack = LocalReference(stackType, freshName("stack"));
           emit(Call(nextStack.name, Ccc(), nextStack.tpe, underflowStack, List(getStack())));
           setStack(nextStack);
-          if (isRegion) {
-            val clearRegion = freshName("clearRegion")
-            popReturnAddressFrom(getStack(), clearRegion)
-            emit(Call("", Ccc(), VoidType(), LocalReference(PointerType(), clearRegion), List(getStack())))
-          }
 
           transform(frame.body);
         }

diff --git a/effekt/shared/src/main/scala/effekt/machine/Analysis.scala b/effekt/shared/src/main/scala/effekt/machine/Analysis.scala
@@ -39,7 +39,7 @@ def freeVariables(statement: Statement): Set[Variable] =
       freeVariables(frame) ++ freeVariables(rest)
     case Return(values) =>
       Set.from(values)
-    case Reset(prompt, frame, isRegion, rest) =>
+    case Reset(prompt, frame, rest) =>
       freeVariables(frame) ++ (freeVariables(rest) -- Set(prompt))
     case Resume(value, rest) =>
       Set(value) ++ freeVariables(rest)

diff --git a/effekt/shared/src/main/scala/effekt/machine/PrettyPrinter.scala b/effekt/shared/src/main/scala/effekt/machine/PrettyPrinter.scala
@@ -75,7 +75,7 @@ object PrettyPrinter extends ParenPrettyPrinter {
     case Return(arguments) =>
       "return" <+> hsep(arguments map toDoc, ",")
 
-    case Reset(prompt, frame, isRegion, rest) =>
+    case Reset(prompt, frame, rest) =>
       "let" <+> prompt <+> "=" <+> "reset" <+> toDoc(frame) <> ";" <> line <> toDoc(rest)
 
     case Resume(stack, rest) =>

diff --git a/effekt/shared/src/main/scala/effekt/machine/Transformer.scala b/effekt/shared/src/main/scala/effekt/machine/Transformer.scala
@@ -211,7 +211,7 @@ object Transformer {
         val returnClause = Clause(List(variable), Return(List(variable)))
         val prompt = Variable(freshName("prompt"), Type.Prompt())
 
-        Reset(prompt, returnClause, false,
+        Reset(prompt, returnClause,
           (bparams zip handlers).foldRight(transform(body)){
             case ((id, handler), body) =>
               New(transform(id), transform(handler, Some(prompt)), body)
@@ -222,7 +222,7 @@ object Transformer {
         val returnClause = Clause(List(variable), Return(List(variable)))
         val prompt = transform(region)
 
-        Reset(prompt, returnClause, true, transform(body))
+        Reset(prompt, returnClause, transform(body))
 
       case core.Alloc(id, init, region, body) =>
         transform(init).run { value =>
@@ -241,11 +241,11 @@ object Transformer {
               val globalPrompt = Variable(freshName("global"), Type.Prompt())
               LiteralInt(globalPrompt, 2L,
                 Shift(temporary, globalPrompt,
-                  Var(reference, value, None,
+                  Var(reference, value, Type.Positive(),
                     Resume(temporary, transform(body)))))
             case _ =>
               Shift(temporary, prompt,
-                Var(reference, value, None,
+                Var(reference, value, Type.Positive(),
                   Resume(temporary, transform(body))))
           }
         }
@@ -256,7 +256,7 @@ object Transformer {
         val prompt = Variable(freshName("prompt"), Type.Prompt())
 
         transform(init).run { value =>
-          Var(reference, value, Some(transform(body.tpe)),
+          Var(reference, value, transform(body.tpe),
             transform(body))
         }
 

diff --git a/effekt/shared/src/main/scala/effekt/machine/Tree.scala b/effekt/shared/src/main/scala/effekt/machine/Tree.scala
@@ -146,7 +146,7 @@ enum Statement {
   /**
    * e.g. var x = 42; s
    */
-  case Var(name: Variable, init: Variable, returnType: Option[Type], rest: Statement)
+  case Var(name: Variable, init: Variable, returnType: Type, rest: Statement)
 
   /**
    * e.g. let y = loadVar(x); s
@@ -171,7 +171,7 @@ enum Statement {
   /**
    * e.g. let prompt = reset { (x, ...) => s }; s
    */
-  case Reset(name: Variable, frame: Clause, isRegion: Boolean, rest: Statement)
+  case Reset(name: Variable, frame: Clause, rest: Statement)
 
   /**
    * e.g. resume k; s