Fix VarInstruction extractor to include IINC

Previously the VarInstruction extractor did not include IINCs.
Also give rename the isVarInstruction predicate to isLoadStoreOrRet,
as it doesn't include IINC.

Also fixes a bug in removeJumpAndAdjustStack, it checked the wrong
opcode range before.

3 files changed, 17 insertions, 12 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzerImpl.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzerImpl.scala
index c933341492..f7ec55f305 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzerImpl.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/ProdConsAnalyzerImpl.scala
@@ -157,7 +157,7 @@ trait ProdConsAnalyzerImpl {
   }
 
   private def isCopyOperation(insn: AbstractInsnNode): Boolean = {
-    isVarInstruction(insn) || {
+    isLoadOrStore(insn) || {
       (insn.getOpcode: @switch) match {
         case DUP | DUP_X1 | DUP_X2 | DUP2 | DUP2_X1 | DUP2_X2 | SWAP | CHECKCAST => true
         case _ => false
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala
index c6f88a4c98..693f735e65 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala
@@ -48,8 +48,9 @@ object BytecodeUtils {
   }
 
   object VarInstruction {
-    def unapply(instruction: AbstractInsnNode): Option[VarInsnNode] = {
-      if (isVarInstruction(instruction)) Some(instruction.asInstanceOf[VarInsnNode])
+    def unapply(instruction: AbstractInsnNode): Option[(AbstractInsnNode, Int)] = {
+      if (isLoadStoreOrRet(instruction)) Some((instruction, instruction.asInstanceOf[VarInsnNode].`var`))
+      else if (instruction.getOpcode == IINC) Some((instruction, instruction.asInstanceOf[IincInsnNode].`var`))
       else None
     }
 
@@ -81,7 +82,9 @@ object BytecodeUtils {
     op >= ISTORE && op <= ASTORE
   }
 
-  def isVarInstruction(instruction: AbstractInsnNode): Boolean = isLoad(instruction) || isStore(instruction)
+  def isLoadStoreOrRet(instruction: AbstractInsnNode): Boolean = isLoad(instruction) || isStore(instruction) || instruction.getOpcode == RET
+
+  def isLoadOrStore(instruction: AbstractInsnNode): Boolean = isLoad(instruction) || isStore(instruction)
 
   def isExecutable(instruction: AbstractInsnNode): Boolean = instruction.getOpcode >= 0
 
@@ -125,7 +128,7 @@ object BytecodeUtils {
   def removeJumpAndAdjustStack(method: MethodNode, jump: JumpInsnNode) {
     val instructions = method.instructions
     val op = jump.getOpcode
-    if ((op >= IFEQ && op <= IFGE) || op == IFNULL || op == IFNONNULL) {
+    if ((op >= IFEQ && op <= IFLE) || op == IFNULL || op == IFNONNULL) {
       instructions.insert(jump, getPop(1))
     } else if ((op >= IF_ICMPEQ && op <= IF_ICMPLE) || op == IF_ACMPEQ || op == IF_ACMPNE) {
       instructions.insert(jump, getPop(1))
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala
index 25e4bb1593..afbf9cf2ce 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala
@@ -310,8 +310,8 @@ object LocalOptImpls {
     val renumber = collection.mutable.ArrayBuffer.empty[Int]
 
     // Add the index of the local variable used by `varIns` to the `renumber` array.
-    def addVar(varIns: VarInsnNode): Unit = {
-      val index = varIns.`var`
+    def addVar(varIns: AbstractInsnNode, slot: Int): Unit = {
+      val index = slot
       val isWide = isSize2LoadOrStore(varIns.getOpcode)
 
       // Ensure the length of `renumber`. Unused variable indices are mapped to -1.
@@ -329,7 +329,7 @@ object LocalOptImpls {
     val firstLocalIndex = parametersSize(method)
     for (i <- 0 until firstLocalIndex) renumber += i // parameters and `this` are always used.
     method.instructions.iterator().asScala foreach {
-      case VarInstruction(varIns) => addVar(varIns)
+      case VarInstruction(varIns, slot) => addVar(varIns, slot)
       case _ =>
     }
 
@@ -350,10 +350,12 @@ object LocalOptImpls {
       // update variable instructions according to the renumber table
       method.maxLocals = nextIndex
       method.instructions.iterator().asScala.foreach {
-        case VarInstruction(varIns) =>
-          val oldIndex = varIns.`var`
-          if (oldIndex >= firstLocalIndex && renumber(oldIndex) != oldIndex)
-            varIns.`var` = renumber(varIns.`var`)
+        case VarInstruction(varIns, slot) =>
+          val oldIndex = slot
+          if (oldIndex >= firstLocalIndex && renumber(oldIndex) != oldIndex) varIns match {
+            case vi: VarInsnNode => vi.`var` = renumber(slot)
+            case ii: IincInsnNode => ii.`var` = renumber(slot)
+          }
         case _ =>
       }
       true