[llvm] [llvm-objdump] Optimize live element tracking (PR #158763)

[via llvm-commits]

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@@ -440,20 +568,60 @@ void LiveElementPrinter::printAfterInst(formatted_raw_ostream &OS) {
 
 void LiveElementPrinter::printStartLine(formatted_raw_ostream &OS,
                                         object::SectionedAddress Addr) {
-  // Print a line to idenfity the start of an inlined function if line format
-  // is specified.
-  if (DbgInlinedFunctions == DFLimitsOnly)
-    for (const std::unique_ptr<LiveElement> &LE : LiveElements)
-      LE->printElementLine(OS, Addr, false);
+  // Only print the start line for inlined functions if DFLimitsOnly is
+  // enabled.
+  if (DbgInlinedFunctions != DFLimitsOnly)
+    return;
+
+  // Use the map to find all elements that start at the given address.
+  std::vector<unsigned> ElementIndices;
+  auto It = LiveElementsByAddress.find(Addr.Address);
+  if (It != LiveElementsByAddress.end()) {
+    for (LiveElement *LE : It->second) {
+      // Look up the ElementIdx from the pointer.
+      auto IndexIt = ElementPtrToIndex.find(LE);
+      if (IndexIt != ElementPtrToIndex.end())
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gulfemsavrun wrote:

It is more reasonable to convert this into an assertion. As long as live elements are correctly populated across all data structures, `IndexIt` will never equal the end iterator.

https://github.com/llvm/llvm-project/pull/158763