[llvm-mca] BackendStatistics: early exit from method printSchedulerUsage if the

no scheduler resources were consumed.

llvm-svn: 327215

1 files changed, 9 insertions, 0 deletions

diff --git a/llvm/tools/llvm-mca/BackendStatistics.cpp b/llvm/tools/llvm-mca/BackendStatistics.cpp
index 46981d5fa61..d310a7b02eb 100644
--- a/llvm/tools/llvm-mca/BackendStatistics.cpp
+++ b/llvm/tools/llvm-mca/BackendStatistics.cpp
@@ -118,9 +118,18 @@ void BackendStatistics::printDispatchStalls(raw_ostream &OS, unsigned RATStalls,
 void BackendStatistics::printSchedulerUsage(
     raw_ostream &OS, const MCSchedModel &SM,
     const ArrayRef<BufferUsageEntry> &Usage) const {
+ 
   std::string Buffer;
   raw_string_ostream TempStream(Buffer);
   TempStream << "\n\nScheduler's queue usage:\n";
+  // Early exit if no buffered resources were consumed.
+  if (Usage.empty()) {
+    TempStream << "No scheduler resources used.\n";
+    TempStream.flush();
+    OS << Buffer;
+    return;
+  }
+
   for (unsigned I = 0, E = SM.getNumProcResourceKinds(); I < E; ++I) {
     const MCProcResourceDesc &ProcResource = *SM.getProcResource(I);
     if (!ProcResource.BufferSize)