+davidxl who might remember the necessary options. It's been a good 3-4 years since we've worked on or used gcc and LIPO, so my memory is pretty stale on the usage model. I never myself worked on the autoFDO tool, so I don't know the options there. A few comments/responses below. On Fri, Feb 19, 2021 at 7:55 PM ijinma <ijinma@xxxxxxxx> wrote: > hi, Johnson > > I happened to see your patches( > https://chromium.googlesource.com/chromiumos/third_party/gcc/+/2eee6942394ea46458d4412d613623fac806247d) > about autoLIPO LIPO in Google GCC. Recently, I was studying autoLIPO( > autoFDO + lipo), but unfortunately, I encountered some problems, so I > want to seek your help. Although the llvm thinLTO has a great advantage, I > still want to try autoLIPO on GCC. I read the source code of the autoFDO > tool briefly, but unfortunately I didn't find a way to enable autoLIPO. > > I want to recreate autoLIPO work, and I think it's worth continuing on > gcc. I think there should be a proper way to turn on autoLIPO, though it > might be very old. But I'm a beginner in the compiler direction, and I'm > not good at all of this. > > So could you give me some help? > > 1. GCC(google gcc_4.8 ?)( > https://chromium.googlesource.com/chromiumos/third_party/gcc/+/refs/heads/svn-mirror/google/gcc-4_8) > and autoFDO(https://github.com/google/autofdo) versions that have been > successfully run by autoLIPO, or some suggestions. > Whatever is the most recent google gcc branch would support autoFDO. I believe that google/gcc_4.8 branch is it. Not sure about the autoFDO tool though, David might know. > > 2. The usage or description of autoFDO enabling auxiliary module. That > is, the imports file generated by AutoFDO stores the grouping algorithm > result of the LIPO module. > I'm not personally familiar with usage of the autoFDO tool, but again, David might remember. > > 3. Or what would I need to do if I wanted to successfully use autoLIPO > on GCC? > If you want to use it with a more recent gcc I'm afraid that is probably going to be a lot of work. I remember each time we synced our google branch with a more recent mainline it required months of work to iron out all of the LIPO interactions, since that wasn't supported by the main gcc branch. Teresa > Looking forward to your reply! > > thanks， > ijinma > -- Teresa Johnson | Software Engineer | tejohnson@xxxxxxxxxx |
