Fix hydrogen statistics output when no code gets optimized.

src/hydrogen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5793 matching lines @@
     PrintF("%30s", names_[i]);
     double ms = static_cast<double>(timing_[i]) / 1000;
     double percent = static_cast<double>(timing_[i]) * 100 / sum;
     PrintF(" - %7.3f ms / %4.1f %% ", ms, percent);
 
     unsigned size = sizes_[i];
     double size_percent = static_cast<double>(size) * 100 / total_size_;
     PrintF(" %8u bytes / %4.1f %%\n", size, size_percent);
   }
   double source_size_in_kb = static_cast<double>(source_size_) / 1024;
+  double normalized_time =  source_size_in_kb > 0
+      ? (static_cast<double>(sum) / 1000) / source_size_in_kb
+      : 0;
+  double normalized_bytes = source_size_in_kb > 0
+      ? total_size_ / source_size_in_kb
+      : 0;
   PrintF("%30s - %7.3f ms           %7.3f bytes\n", "Sum",
-         (static_cast<double>(sum) / 1000) / source_size_in_kb,
-         total_size_ / source_size_in_kb);
+         normalized_time, normalized_bytes);
   PrintF("---------------------------------------------------------------\n");
   PrintF("%30s - %7.3f ms (%.1f times slower than full code gen)\n",
          "Total",
          static_cast<double>(total_) / 1000,
          static_cast<double>(total_) / full_code_gen_);
 }
 
 
 void HStatistics::SaveTiming(const char* name, int64_t ticks, unsigned size) {
   if (name == HPhase::kFullCodeGen) {
@@ skipping 51 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal