alexfh added a comment. In rGc93f93b2e3f28997f794265089fb8138dd5b5f13#1039669 <https://reviews.llvm.org/rGc93f93b2e3f28997f794265089fb8138dd5b5f13#1039669>, @bgraur wrote:
> Early heads up that this revision causes a large regression in compilation > time for some of our internal source files: we are seeing an almost 20x > increase in compilation times for some files (from 42s to 728s). > > I'm working on a reproducer which I'm going to upload when ready. We're still reducing it, but the test case is a different one as the one I posted in https://reviews.llvm.org/D106056#3023708. Similar to https://reviews.llvm.org/D106056, adding `-mllvm -disable-early-taildup=true` reduces the compilation time to normal. `perf record --call-graph lbr clang -xc++ -std=gnu++17 -c -O3 test.ii` results in the profile below: - 99.28% 0.00% clang clang [.] llvm::FPPassManager::runOnFunction ◆ - 99.27% llvm::FPPassManager::runOnFunction ▒ - 99.24% llvm::MachineFunctionPass::runOnFunction ▒ - 97.51% (anonymous namespace)::MachineBlockPlacement::runOnMachineFunction ▒ - 97.51% (anonymous namespace)::MachineBlockPlacement::buildCFGChains ▒ - 97.45% (anonymous namespace)::MachineBlockPlacement::buildChain ▒ - 96.82% (anonymous namespace)::MachineBlockPlacement::canTailDuplicateUnplacedPreds ▒ 94.66% hasSameSuccessors ▒ Hope this helps finding out the cause of the problem. It would be helpful, if you could revert the commit while you're investigating. BRANCHES fix_asan, main Users: junparser (Author) https://reviews.llvm.org/rGc93f93b2e3f2 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
