[PATCH] D21166: [wip] COFF: New symbol table design.

[Rui Ueyama via Phabricator via llvm-commits]

ruiu added a comment.

I think I want to get this in to close the architectural difference between COFF and ELF, and I like it removes the half-baked parallel file parsing.

> So now that I'm able to link chrome_child.dll on Linux it turns out that I get very different results with "perf stat":
> 
> Before (median of 5 runs): 11.623297415 seconds time elapsed
>  After: 8.123567205 seconds time elapsed



  #include <sys/time.h>
  
  static uint64_t microsec(struct timespec Time) {
    return Time.tv_sec * 1000000 + (Time.tv_nsec / 1000);
  }
  
  void elf::log2(const Twine &Msg) {
    static uint64_t Start = 0;
    struct timespec Time;
    clock_gettime(CLOCK_MONOTONIC, &Time);
    if (Start == 0)
      Start = microsec(Time);
    llvm::errs() << (microsec(Time) - Start) << " " << Msg << "\n";
  }

I often add this piece of code to measure time of each pass. This is hacky but still better than `time` command. Did you try to measure this patch on Windows?



================
Comment at: lld/COFF/SymbolTable.cpp:78
     if (Config->Verbose)
-      outs() << "Reading " << toString(File) << "\n";
+      llvm::outs() << "Reading " << toString(File) << "\n";
+    File->parse();
----------------
Remove `llvm::` from here and other places.


https://reviews.llvm.org/D21166