JIT: Add rootTreeOp to DumpFg (#50119)

1 files changed, 8 insertions, 0 deletions

diff --git a/src/coreclr/jit/fgdiagnostic.cpp b/src/coreclr/jit/fgdiagnostic.cpp
index 6ad412709ca..1ae0151a9ba 100644
--- a/src/coreclr/jit/fgdiagnostic.cpp
+++ b/src/coreclr/jit/fgdiagnostic.cpp
@@ -822,10 +822,18 @@ bool Compiler::fgDumpFlowGraph(Phases phase)
             {
                 fprintf(fgxFile, "\n            loopHead=\"true\"");
             }
+
+            const char* rootTreeOpName = "n/a";
+            if (block->lastNode() != nullptr)
+            {
+                rootTreeOpName = GenTree::OpName(block->lastNode()->OperGet());
+            }
+
             fprintf(fgxFile, "\n            weight=");
             fprintfDouble(fgxFile, ((double)block->bbWeight) / weightDivisor);
             fprintf(fgxFile, "\n            codeEstimate=\"%d\"", fgGetCodeEstimate(block));
             fprintf(fgxFile, "\n            startOffset=\"%d\"", block->bbCodeOffs);
+            fprintf(fgxFile, "\n            rootTreeOp=\"%s\"", rootTreeOpName);
             fprintf(fgxFile, "\n            endOffset=\"%d\"", block->bbCodeOffsEnd);
             fprintf(fgxFile, ">");
             fprintf(fgxFile, "\n        </block>");