diff --git a/runtime/compiler/codegen/CodeGenPhaseToPerform.hpp b/runtime/compiler/codegen/CodeGenPhaseToPerform.hpp
index 2eeb924b32..5b6989728c 100644
--- a/runtime/compiler/codegen/CodeGenPhaseToPerform.hpp
+++ b/runtime/compiler/codegen/CodeGenPhaseToPerform.hpp
@@ -41,7 +41,6 @@
     LowerTreesPhase,
     InsertDebugCountersPhase,
     CompressedReferenceRematerializationPhase,
-    SplitWarmAndColdBlocksPhase,
     AllocateLinkageRegisters,
 
     IdentifyUnneededByteConvsPhase,
diff --git a/runtime/compiler/codegen/J9CodeGenPhase.cpp b/runtime/compiler/codegen/J9CodeGenPhase.cpp
index b6f9b3afd2..63044aa452 100644
--- a/runtime/compiler/codegen/J9CodeGenPhase.cpp
+++ b/runtime/compiler/codegen/J9CodeGenPhase.cpp
@@ -118,12 +118,6 @@ J9::CodeGenPhase::performCompressedReferenceRematerializationPhase(TR::CodeGener
    cg->compressedReferenceRematerialization();
    }
 
-void
-J9::CodeGenPhase::performSplitWarmAndColdBlocksPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *)
-   {
-   cg->splitWarmAndColdBlocks();
-   }
-
 const char *
 J9::CodeGenPhase::getName()
    {
@@ -145,8 +139,6 @@ J9::CodeGenPhase::getName(TR::CodeGenPhase::PhaseValue phase)
          return "InsertEpilogueYieldPoints";
       case CompressedReferenceRematerializationPhase:
          return "CompressedReferenceRematerialization";
-      case SplitWarmAndColdBlocksPhase:
-         return "SplitWarmAndColdBlocks";
       case IdentifyUnneededByteConvsPhase:
 	      return "IdentifyUnneededByteConvsPhase";
       case LateSequentialConstantStoreSimplificationPhase:
diff --git a/runtime/compiler/codegen/J9CodeGenPhase.hpp b/runtime/compiler/codegen/J9CodeGenPhase.hpp
index 541e1a6142..7d4ce8b8ae 100644
--- a/runtime/compiler/codegen/J9CodeGenPhase.hpp
+++ b/runtime/compiler/codegen/J9CodeGenPhase.hpp
@@ -53,7 +53,6 @@ class OMR_EXTENSIBLE CodeGenPhase: public OMR::CodeGenPhaseConnector
    static void performMoveUpArrayLengthStoresPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *);
    static void performInsertEpilogueYieldPointsPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *);
    static void performCompressedReferenceRematerializationPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *);
-   static void performSplitWarmAndColdBlocksPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *);
    static void performIdentifyUnneededByteConvsPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *);
    static void performLateSequentialConstantStoreSimplificationPhase(TR::CodeGenerator * cg, TR::CodeGenPhase *);
 
diff --git a/runtime/compiler/codegen/J9CodeGenPhaseEnum.hpp b/runtime/compiler/codegen/J9CodeGenPhaseEnum.hpp
index 60023faff2..42253ef551 100644
--- a/runtime/compiler/codegen/J9CodeGenPhaseEnum.hpp
+++ b/runtime/compiler/codegen/J9CodeGenPhaseEnum.hpp
@@ -35,7 +35,6 @@
    MoveUpArrayLengthStoresPhase,
    InsertEpilogueYieldPointsPhase,
    CompressedReferenceRematerializationPhase,
-   SplitWarmAndColdBlocksPhase,
    IdentifyUnneededByteConvsPhase,
    LateSequentialConstantStoreSimplificationPhase,  // all
    LastJ9Phase = LateSequentialConstantStoreSimplificationPhase,
diff --git a/runtime/compiler/codegen/J9CodeGenPhaseFunctionTable.hpp b/runtime/compiler/codegen/J9CodeGenPhaseFunctionTable.hpp
index 857651a83a..e433513518 100644
--- a/runtime/compiler/codegen/J9CodeGenPhaseFunctionTable.hpp
+++ b/runtime/compiler/codegen/J9CodeGenPhaseFunctionTable.hpp
@@ -34,6 +34,5 @@
    TR::CodeGenPhase::performMoveUpArrayLengthStoresPhase,                                    //MoveUpArrayLengthStoresPhase
    TR::CodeGenPhase::performInsertEpilogueYieldPointsPhase,                                  //InsertEpilogueYieldPointsPhase
    TR::CodeGenPhase::performCompressedReferenceRematerializationPhase,
-   TR::CodeGenPhase::performSplitWarmAndColdBlocksPhase,
    TR::CodeGenPhase::performIdentifyUnneededByteConvsPhase,                                  //IdentifyUnneededByteConvsPhase
    TR::CodeGenPhase::performLateSequentialConstantStoreSimplificationPhase,                  //LateSequentialConstantStoreSimplificationPhase
diff --git a/runtime/compiler/codegen/J9CodeGenerator.cpp b/runtime/compiler/codegen/J9CodeGenerator.cpp
index f40baa4d63..58513a533d 100644
--- a/runtime/compiler/codegen/J9CodeGenerator.cpp
+++ b/runtime/compiler/codegen/J9CodeGenerator.cpp
@@ -2266,143 +2266,6 @@ J9::CodeGenerator::doInstructionSelection()
       diagnostic("</selection>\n");
    }
 
-
-// J9, Z
-//
-// This can surely be done more efficiently.  Walk the CFG and go block by block
-// rather than iterating through TreeTops looking for BBStarts.
-//
-void
-J9::CodeGenerator::splitWarmAndColdBlocks()
-   {
-   if (!self()->allowSplitWarmAndColdBlocks() || self()->comp()->compileRelocatableCode())
-      {
-      return;
-      }
-
-   TR::Block * block = NULL;
-   TR::TreeTop * tt;
-   TR::Node * node;
-   TR::Block * firstColdBlock = NULL, * firstColdExtendedBlock = NULL;
-
-   for (tt = self()->comp()->getStartTree(); tt; tt = tt->getNextTreeTop())
-      {
-      node = tt->getNode();
-
-      if (node->getOpCodeValue() == TR::BBStart)
-         {
-         block = node->getBlock();
-
-         // If this is the first cold block, remember where the warm blocks ended.
-         // If it is a warm block and cold blocks have already been found, they
-         // are treated as warm.
-         //
-         if (block->isCold())
-            {
-            if (!firstColdBlock)
-               firstColdBlock = block;
-            }
-         else
-            {
-            firstColdBlock = NULL;
-            firstColdExtendedBlock = NULL;
-            }
-
-         if (!block->isExtensionOfPreviousBlock())
-            {
-            if (firstColdBlock && !firstColdExtendedBlock)
-               {
-               if (!block->getPrevBlock() ||
-                   !block->getPrevBlock()->canFallThroughToNextBlock())
-                  firstColdExtendedBlock = block;
-               else
-                  firstColdBlock = NULL;
-               }
-            }
-         }
-      }
-
-   // Mark the split point between warm and cold blocks, so they can be
-   // allocated in different code sections.
-   //
-   TR::Block *lastWarmBlock;
-   if (firstColdExtendedBlock)
-      {
-      lastWarmBlock = firstColdExtendedBlock->getPrevBlock();
-      if (!lastWarmBlock)
-         {
-         // All the blocks are cold: insert a new goto block ahead of real blocks
-         lastWarmBlock = TR::TransformUtil::insertNewFirstBlockForCompilation(self()->comp());
-         }
-      }
-   else
-      {
-      // All the blocks are warm - the split point is between the last
-      // instruction and the snippets.
-      //
-      lastWarmBlock = block;
-      }
-
-   // If the last tree in the last warm block is not a TR::Goto, insert a goto tree
-   // at the end of the block.
-   // If there is a following block the goto will branch to it so that when the
-   // code is split any fall-through will go to the right place.
-   // If there is no following block the goto will branch to the first block; in
-   // this case the goto should never be reached, it is there only to
-   // make sure that the instruction following the last real treetop will be in
-   // warm code, so if it is a helper call (e.g. for a throw) the return address
-   // is in this method's code.
-   //
-   if (lastWarmBlock->getNumberOfRealTreeTops() == 0)
-      tt = lastWarmBlock->getEntry();
-   else
-      tt = lastWarmBlock->getLastRealTreeTop();
-
-   node = tt->getNode();
-
-   if (!(node->getOpCode().isGoto() || node->getOpCode().isJumpWithMultipleTargets() || node->getOpCode().isReturn()))
-      {
-      // Find the block to be branched to
-      //
-      TR::TreeTop * targetTreeTop = lastWarmBlock->getExit()->getNextTreeTop();
-      if (targetTreeTop)
-         {
-         // Branch to following block. Make sure it is not marked as an
-         // extension block so that it will get a label generated.
-         //
-         targetTreeTop->getNode()->getBlock()->setIsExtensionOfPreviousBlock(false);
-         }
-      else
-         {
-         // Branch to the first block. This will not be marked as an extension
-         // block.
-         targetTreeTop = self()->comp()->getStartBlock()->getEntry();
-         }
-
-      // Generate the goto and insert it into the end of the last warm block.
-      //
-      TR::TreeTop *gotoTreeTop = TR::TreeTop::create(self()->comp(), TR::Node::create(node, TR::Goto, 0, targetTreeTop));
-
-      // Move reg deps from BBEnd to goto
-      //
-      TR::Node *bbEnd = lastWarmBlock->getExit()->getNode();
-      if (bbEnd->getNumChildren() > 0)
-         {
-         TR::Node *glRegDeps = bbEnd->getChild(0);
-
-         gotoTreeTop->getNode()->setNumChildren(1);
-         gotoTreeTop->getNode()->setChild(0, glRegDeps);
-
-         bbEnd->setChild(0,NULL);
-         bbEnd->setNumChildren(0);
-         }
-
-      tt->insertAfter(gotoTreeTop);
-      }
-
-   }
-
-
 void
 J9::CodeGenerator::populateOSRBuffer()
    {
diff --git a/runtime/compiler/codegen/J9CodeGenerator.hpp b/runtime/compiler/codegen/J9CodeGenerator.hpp
index 7a035fc642..233bfb4274 100644
--- a/runtime/compiler/codegen/J9CodeGenerator.hpp
+++ b/runtime/compiler/codegen/J9CodeGenerator.hpp
@@ -101,8 +101,6 @@ class OMR_EXTENSIBLE CodeGenerator : public OMR::CodeGeneratorConnector
 
    void insertEpilogueYieldPoints();
 
-   void splitWarmAndColdBlocks(); // J9 & Z
-
    void allocateLinkageRegisters();
 
    void fixUpProfiledInterfaceGuardTest();
diff --git a/runtime/compiler/z/codegen/CodeGenPhaseToPerform.hpp b/runtime/compiler/z/codegen/CodeGenPhaseToPerform.hpp
index c28fb50585..6d821251e1 100644
--- a/runtime/compiler/z/codegen/CodeGenPhaseToPerform.hpp
+++ b/runtime/compiler/z/codegen/CodeGenPhaseToPerform.hpp
@@ -42,7 +42,6 @@
     LowerTreesPhase,
     InsertDebugCountersPhase,
     CompressedReferenceRematerializationPhase,
-    SplitWarmAndColdBlocksPhase,
     AllocateLinkageRegisters,
 
     markLoadAsZeroOrSignExtension,
diff --git a/runtime/compiler/z/codegen/J9CodeGenerator.hpp b/runtime/compiler/z/codegen/J9CodeGenerator.hpp
index d37c31d001..ed09dfdf9d 100644
--- a/runtime/compiler/z/codegen/J9CodeGenerator.hpp
+++ b/runtime/compiler/z/codegen/J9CodeGenerator.hpp
@@ -231,8 +231,6 @@ class OMR_EXTENSIBLE CodeGenerator : public J9::CodeGenerator
    bool canCopyWithOneOrTwoInstrs(char *lit, size_t size);
    bool inlineSmallLiteral(size_t srcSize, char *srcLiteral, size_t destSize, bool trace);
 
-   bool allowSplitWarmAndColdBlocks() { return true; }
-
 #if defined(J9VM_JIT_FREE_SYSTEM_STACK_POINTER)
    /** \brief
     *     Determines whether the JIT supports freeing up the system stack pointer (SSP) for register allocation.