)]}'
{
  "commit": "cb49bb00d9240475eb57976de1b7351f4e3f81ad",
  "tree": "12d36d3ae0de09ea0fbc1140f9916d899bc7a5fa",
  "parents": [
    "f5cd71c5cf9404c1e1afcdc2e45712adeaddb3e9"
  ],
  "author": {
    "name": "DRC",
    "email": "information@libjpeg-turbo.org",
    "time": "Tue Feb 02 23:10:27 2016 -0600"
  },
  "committer": {
    "name": "DRC",
    "email": "information@libjpeg-turbo.org",
    "time": "Tue Feb 02 23:14:27 2016 -0600"
  },
  "message": "Opt. ARM64 SIMD decompr. for in-order pipelines\n\nDecompression speedup relative to libjpeg-turbo 1.4.2 (ISLOW IDCT):\n48-core ThunderX (RunAbove ARM Cloud), Linux, 64-bit: 60-113% (avg. 86%)\nCortex-A53 (Nexus 5X), Android, 64-bit: 6.8-27% (avg. 14%)\nCortex-A57 (Nexus 5X), Android, 64-bit: 2.0-14% (avg. 6.8%)\n\nDecompression speedup relative to libjpeg-turbo 1.4.2 (IFAST IDCT):\n48-core ThunderX (RunAbove ARM Cloud), Linux, 64-bit: 51-98% (avg. 75%)\n\nMinimal speedup (1-5%) observed on iPhone 5S (Cortex-A7)\n\nNOTE: This commit avoids the st3 instruction for non-Android and\nnon-Apple builds, which may cause a performance regression against\nlibjpeg-turbo 1.4.x on ARM64 systems that are running plain Linux.\nSince ThunderX is the only platform known to suffer from slow ld3 and\nst3 instructions, it is probably better to check for the CPU type\nat run time and disable ld3/st3 only if ThunderX is detected.\n\nThis commit also enables the use of ld3 on Android platforms, which\nshould be a safe bet, at least for now.  This speeds up compression on\nthe afore-mentioned Nexus Cortex-A53 by 5.5-19% (avg. 12%) and on the\nNexus Cortex-A57 by 1.2-14% (avg. 6.3%), relative to the previous\ncommits.\n\nThis commit also removes unnecessary macros.\n\nRefer to #52 for discussion.\n\nCloses #52.\n\nBased on:\nhttps://github.com/mayeut/libjpeg-turbo/commit/6bad905034e6e73b33ebf07a74a6b72f58319f62\nhttps://github.com/mayeut/libjpeg-turbo/commit/488dd7bf1726e2f6af6e9294ccf77b729fec1f20\nhttps://github.com/mayeut/libjpeg-turbo/commit/4f4d057c1fb31d643536e6effb46a5946e15c465\nhttps://github.com/mayeut/libjpeg-turbo/commit/d3198afc43450989a4fc63d2dcbe3272c8a0a3c1\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "936c69a72b9d0a1faa69eb31adfe43d9cc4d2617",
      "old_mode": 33188,
      "old_path": "simd/jsimd_arm64_neon.S",
      "new_id": "5acb7134886687a59b708181a347b405c0609494",
      "new_mode": 33188,
      "new_path": "simd/jsimd_arm64_neon.S"
    }
  ]
}