Split DCE from Optimizer phase

Author: mattisboeckle

effekt/shared/src/main/scala/effekt/core/DeadCodeElimination.scala

@@ -0,0 +1,20 @@
+package effekt.core
+
+import effekt.PhaseResult.CoreTransformed
+import effekt.context.Context
+import effekt.core.optimizer.Deadcode
+import effekt.Phase
+
+object DeadCodeElimination extends Phase[CoreTransformed, CoreTransformed] {
+    val phaseName: String = "deadcode-elimination"
+
+    def run(input: CoreTransformed)(using Context): Option[CoreTransformed] =
+        input match {
+            case CoreTransformed(source, tree, mod, core) => 
+                val term = Context.checkMain(mod)
+                val dce = Context.timed("deadcode-elimination", source.name) {
+                    Deadcode.remove(term, core)
+                }
+                Some(CoreTransformed(source, tree, mod, dce))
+        }
+}

effekt/shared/src/main/scala/effekt/core/optimizer/Optimizer.scala

@@ -23,10 +23,10 @@ object Optimizer extends Phase[CoreTransformed, CoreTransformed] {
 
     var tree = core
 
-     // (1) first thing we do is simply remove unused definitions (this speeds up all following analysis and rewrites)
-    tree = Context.timed("deadcode-elimination", source.name) {
-      Deadcode.remove(mainSymbol, tree)
-    }
+    // (1) first thing we do is simply remove unused definitions (this speeds up all following analysis and rewrites)
+    // tree = Context.timed("deadcode-elimination", source.name) {
+    //   Deadcode.remove(mainSymbol, tree)
+    // }
 
     if !Context.config.optimize() then return tree;
 

effekt/shared/src/main/scala/effekt/generator/llvm/LLVM.scala

@@ -7,6 +7,8 @@ import effekt.core.optimizer
 import effekt.machine
 import kiama.output.PrettyPrinterTypes.{ Document, emptyLinks }
 import kiama.util.Source
+import effekt.core.DeadCodeElimination
+import effekt.generator.chez.DeadCodeElimination
 
 
 class LLVM extends Compiler[String] {
@@ -52,7 +54,7 @@ class LLVM extends Compiler[String] {
   // -----------------------------------
   object steps {
     // intermediate steps for VSCode
-    val afterCore = allToCore(Core) andThen Aggregate andThen optimizer.Optimizer andThen core.PolymorphismBoxing
+    val afterCore = allToCore(Core) andThen Aggregate andThen core.DeadCodeElimination andThen optimizer.Optimizer andThen core.PolymorphismBoxing
     val afterMachine = afterCore andThen Machine map { case (mod, main, prog) => prog }
     val afterLLVM = afterMachine map {
       case machine.Program(decls, defns, entry) =>