Bug fix (eclipse-openj9#19947)

A crash was occuring in Unsafe.get/put() case (6) when trying to modify the CFG to include the newly generated directAccessBlock. To avoid this, we can simply append the directAccessTreeTop onto the previous block (beforeCallBlock), which elimiates the need to update the CFG, since no new blocks are added. Additionally, without this commit, these two blocks (in addition to the one after the directAccessBlock, joinBlock), would get merged during block simplication anyways: so this fix eliminates the need to perform that optimization later down the line. Signed-off-by: midronij <[email protected]>
rmnattas · Sep 5, 2024 · e8eed23 · e8eed23
1 parent 74afeb1
commit e8eed23
Showing 1 changed file with 4 additions and 22 deletions.
diff --git a/runtime/compiler/optimizer/InlinerTempForJ9.cpp b/runtime/compiler/optimizer/InlinerTempForJ9.cpp
@@ -1065,17 +1065,8 @@ TR_J9InlinerPolicy::genCodeForUnsafeGetPut(TR::Node* unsafeAddress,
       //SPECIAL CASE
       if (!directAccessWithConversionTreeTop && conversionNeeded)
          {
-         //Generating block for arrayDirectAccess (direct access with conversion)
-         arrayDirectAccessBlock = TR::Block::createEmptyBlock(callNodeTreeTop->getNode(), comp(),
-                                                              joinBlock->getFrequency());
-         arrayDirectAccessBlock->append(arrayDirectAccessTreeTop);
-         beforeCallBlock->getExit()->insertTreeTopsAfterMe(arrayDirectAccessBlock->getEntry(), arrayDirectAccessBlock->getExit());
-
-         //add arrayDirectAccessBlock to cfg
-         cfg->addNode(arrayDirectAccessBlock);
-         cfg->addEdge(TR::CFGEdge::createEdge(beforeCallBlock, arrayDirectAccessBlock, trMemory()));
-         cfg->addEdge(TR::CFGEdge::createEdge(arrayDirectAccessBlock, joinBlock, trMemory()));
-         cfg->removeEdge(beforeCallBlock, joinBlock);
+         //Since no runtime tests are being performed, we can simply append the arrayDirectAccessTreeTop to beforeCallBlock
+         beforeCallBlock->append(arrayDirectAccessTreeTop);
          }
       else
          {
@@ -1093,17 +1084,8 @@ TR_J9InlinerPolicy::genCodeForUnsafeGetPut(TR::Node* unsafeAddress,
       }
    else // CASE (6)
       {
-      //Generating block for direct access
-      directAccessBlock = TR::Block::createEmptyBlock(callNodeTreeTop->getNode(), comp(),
-                                                      joinBlock->getFrequency());
-      directAccessBlock->append(directAccessTreeTop);
-      beforeCallBlock->getExit()->insertTreeTopsAfterMe(directAccessBlock->getEntry(), directAccessBlock->getExit());
-
-      //add directAccessBlock to cfg
-      cfg->addNode(directAccessBlock);
-      cfg->addEdge(TR::CFGEdge::createEdge(beforeCallBlock, directAccessBlock, trMemory()));
-      cfg->addEdge(TR::CFGEdge::createEdge(directAccessBlock, joinBlock, trMemory()));
-      cfg->removeEdge(beforeCallBlock, joinBlock);
+      //Since no runtime tests are being performed, we can simply append the directAccessTreeTop to beforeCallBlock
+      beforeCallBlock->append(directAccessTreeTop);
       }
 
    if (directAccessBlock)