I'm working on a pnacl app that uses popcnt (stockfish).

While pnacl-translate can produce code with the popcnt instruction if passed -mattr=+popcnt, I don't see it in the binary generated by chrome. It like popcnt support was never added -- was there a reason or just oversight?


components/nacl/renderer/platform_info.cc
  // On x86, SSE features are ordered: the most recent one implies the
  // others. Care is taken here to only specify the latest SSE version,
  // whereas non-SSE features don't follow this model: POPCNT is
  // effectively always implied by SSE4.2 but has to be specified
  // separately.
  //
  // TODO: AVX2, AVX, SSE 4.2.
  if (cpu.has_sse41()) features.push_back("+sse4.1");
  // TODO: SSE 4A, SSE 4.
  else if (cpu.has_ssse3()) features.push_back("+ssse3");
  // TODO: SSE 3
  else if (cpu.has_sse2()) features.push_back("+sse2");

  // TODO: AES, POPCNT, LZCNT, ...
  return base::JoinString(features, ",");