Demo

[grimar]

Summary

Not for reviews. Just a demo.
Integrates .gdb_index building benchmark into LLD.

ELF/Writer.cpp

 #include "SymbolTable.h"
 #include "SyntheticSections.h"
 #include "Target.h"
 #include "Threads.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/FileOutputBuffer.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Timer.h"
 #include <climits>
 
 using namespace llvm;
 using namespace llvm::ELF;
 using namespace llvm::object;
 using namespace llvm::support;
 using namespace llvm::support::endian;
 
if (Config->EMachine == EM_MIPS) {
     Add(InX::Got);
   }
 
   InX::GotPlt = make<GotPltSection>();
   Add(InX::GotPlt);
   InX::IgotPlt = make<IgotPltSection>();
   Add(InX::IgotPlt);
 
+  double TotalWallTime = 0.0;
+  double Min = std::numeric_limits<double>::max();
+  double Max = std::numeric_limits<double>::min();
+  uint64_t N = 0;
+
   if (Config->GdbIndex) {
+    Timer T("Name", "Desc");
+
+    while (++N) {
+      T.startTimer();
       InX::GdbIndex = createGdbIndex<ELFT>();
+      T.stopTimer();
+
+      double WallT = T.getTotalTime().getWallTime();
+      T.clear();
+
+      Min = std::min(Min, WallT);
+      Max = std::max(Max, WallT);
+      TotalWallTime += WallT;
+
+      outs() << "Avg: " << (TotalWallTime / N) << ", N: " << N
+             << " Min: " << Min << ", Max: " << Max << ", Last: " << WallT
+             << "\n";
+      outs().flush();
+    }
+
     Add(InX::GdbIndex);
   }
 
   // We always need to add rel[a].plt to output if it has entries.
   // Even for static linking it can contain R_[*]_IRELATIVE relocations.
   In<ELFT>::RelaPlt = make<RelocationSection<ELFT>>(
       Config->IsRela ? ".rela.plt" : ".rel.plt", false /*Sort*/);
   Add(In<ELFT>::RelaPlt);