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

[James Henderson via llvm-commits]

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@@ -126,8 +121,35 @@ void LiveElementPrinter::addInlinedFunction(DWARFDie FuncDie,
   DWARFUnit *U = InlinedFuncDie.getDwarfUnit();
   const char *InlinedFuncName = InlinedFuncDie.getName(DINameKind::LinkageName);
   DWARFAddressRange Range{FuncLowPC, FuncHighPC, SectionIndex};
+  // Add the new element to the main vector.
   LiveElements.emplace_back(std::make_unique<InlinedFunction>(
       InlinedFuncName, U, FuncDie, InlinedFuncDie, Range));
+  // Map the element's low address (LowPC) to its pointer for fast range start
+  // lookup.
+  LiveElementsByAddress[FuncLowPC].push_back(LiveElements.back().get());
+  // Map the element's high address (HighPC) to its pointer for fast range end
+  // lookup.
+  LiveElementsByEndAddress[FuncHighPC].push_back(LiveElements.back().get());
+  // Map the pointer to its DWARF discovery index for deterministic
+  // ordering.
+  ElementPtrToIndex[LiveElements.back().get()] = LiveElements.size() - 1;
+}
+
+/// Registers the most recently added LiveVariable into all data structures.
+void LiveElementPrinter::registerNewVariable() {
+  assert(
+      !LiveElements.empty() &&
+      "registerNewVariable called before element was added to LiveElements.");
+  LiveVariable *CurrentVar =
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jh7370 wrote:

Perhaps worth an assertion that `CurrentVar` isn't already in  `ElementPtrToIndex`?

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