diff --git a/src/main/scala/millfork/assembly/mos/opt/CpuStatus.scala b/src/main/scala/millfork/assembly/mos/opt/CpuStatus.scala
index 014d7a2a..c1bafdb6 100644
--- a/src/main/scala/millfork/assembly/mos/opt/CpuStatus.scala
+++ b/src/main/scala/millfork/assembly/mos/opt/CpuStatus.scala
@@ -160,11 +160,6 @@ case class CpuStatus(a: Status[Int] = UnknownStatus,
   }
 
   def hasSet(state: State.Value): Boolean = state match {
-    case State.A => false
-    case State.AH => false
-    case State.X => false
-    case State.Y => false
-    case State.IZ => false
     case State.Z => z.contains(true)
     case State.N => n.contains(true)
     case State.C => c.contains(true)
diff --git a/src/main/scala/millfork/assembly/mos/opt/FlowAnalyzer.scala b/src/main/scala/millfork/assembly/mos/opt/FlowAnalyzer.scala
index 375e9ef0..2d950c25 100644
--- a/src/main/scala/millfork/assembly/mos/opt/FlowAnalyzer.scala
+++ b/src/main/scala/millfork/assembly/mos/opt/FlowAnalyzer.scala
@@ -21,12 +21,16 @@ case class FlowInfo(holder: FlowHolder, index: Int, _labelUseCountMap: () => Opt
   lazy val importanceAfter: CpuImportance = holder.importanceAfter(index)
   lazy val labelUseCountMap: Option[Map[String, Int]] = _labelUseCountMap()
 
+  @inline
   def hasClear(state: State.Value): Boolean = statusBefore.hasClear(state)
 
+  @inline
   def hasSet(state: State.Value): Boolean = statusBefore.hasSet(state)
 
+  @inline
   def isUnimportant(state: State.Value): Boolean = importanceAfter.isUnimportant(state)
 
+  @inline
   def labelUseCount(label: String): Int = labelUseCountMap.map(_.getOrElse(label, 0)).getOrElse(-1)
 
   override def toString: String = holder.toString(index)
diff --git a/src/main/scala/millfork/env/Environment.scala b/src/main/scala/millfork/env/Environment.scala
index 1c67ee54..8e268832 100644
--- a/src/main/scala/millfork/env/Environment.scala
+++ b/src/main/scala/millfork/env/Environment.scala
@@ -295,18 +295,20 @@ class Environment(val parent: Option[Environment], val prefix: String, val cpuFa
 
   private def removeVariableImpl(str: String): Unit = {
     def extractThingName(fullName: String): String = {
-      var result = fullName.takeWhile(_ != '.')
-      if (result.length == fullName.length) return result
-      val suffix = fullName.drop(result.length)
+      val ix = fullName.indexOf('.')
+      if (ix < 0) return fullName
+      var result = fullName.substring(0, ix)
+      val suffix = fullName.substring(ix)
       if (suffix == ".return" || suffix.startsWith(".return.")) {
         result += ".return"
       }
       result
     }
 
+    val strWithoutPrefix = str.stripPrefix(prefix)
     val toRemove = things.keys.filter { n =>
       val baseName = extractThingName(n)
-      baseName == str || baseName == str.stripPrefix(prefix)
+      baseName == str || baseName == strWithoutPrefix
     }.toSet
     removedThings ++= toRemove.map(_.stripPrefix(prefix))
     things --= toRemove