diff --git a/clang/docs/UsersManual.rst b/clang/docs/UsersManual.rst --- a/clang/docs/UsersManual.rst +++ b/clang/docs/UsersManual.rst @@ -2241,6 +2241,15 @@ $ clang++ -O2 -gline-tables-only -fprofile-sample-use=code.prof code.cc -o code + [OPTIONAL] Sampling-based profiles can have inaccuracies or missing block/ + edge counters. The profile inference algorithm (profi) can be used to infer + missing blocks and edge counts, and improve the quality of profile data. + Enable it with ``-fsample-profile-use-profi``. + + .. code-block:: console + + $ clang++ -O2 -gline-tables-only -fprofile-sample-use=code.prof \ + -fsample-profile-use-profi code.cc -o code Sample Profile Formats """""""""""""""""""""" diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -1251,6 +1251,13 @@ as cold. Otherwise, treat callsites without profile samples as if we have no profile}]>, MarshallingInfoFlag>; +def fsample_profile_use_profi : Flag<["-"], "fsample-profile-use-profi">, + Flags<[NoXarchOption, CC1Option]>, Group, + HelpText<"Use profi to infer block and edge counts">, + DocBrief<[{Infer block and edge counts. If the profiles have errors or missing + blocks caused by sampling, profile inference (profi) can convert + basic block counts to branch probabilites to fix them by extended + and re-engineered classic MCMF (min-cost max-flow) approach.}]>; def fno_profile_sample_accurate : Flag<["-"], "fno-profile-sample-accurate">, Group, Flags<[NoXarchOption]>; def fauto_profile : Flag<["-"], "fauto-profile">, Group, diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp --- a/clang/lib/Driver/ToolChains/Clang.cpp +++ b/clang/lib/Driver/ToolChains/Clang.cpp @@ -5729,6 +5729,12 @@ Args.AddLastArg(CmdArgs, options::OPT_fclang_abi_compat_EQ); + if (getLastProfileSampleUseArg(Args) && + Args.hasArg(options::OPT_fsample_profile_use_profi)) { + CmdArgs.push_back("-mllvm"); + CmdArgs.push_back("-sample-profile-use-profi"); + } + // Add runtime flag for PS4/PS5 when PGO, coverage, or sanitizers are enabled. if (RawTriple.isPS() && !Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) { diff --git a/clang/test/Driver/pgo-sample-use-profi.c b/clang/test/Driver/pgo-sample-use-profi.c new file mode 100644 --- /dev/null +++ b/clang/test/Driver/pgo-sample-use-profi.c @@ -0,0 +1,4 @@ +/// Test if profi flat is enabled in frontend as user-facing feature. +// RUN: %clang -c -fsample-profile-use-profi -fprofile-sample-use=/dev/null -### %s 2>&1 | FileCheck %s + +// CHECK: "-mllvm" "-sample-profile-use-profi"