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[Driver] Add -fsample-profile-use-profi

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This patch enable `-sample-profile-use-profi` in Clang frontend as user-facing
feature. By using this patch, we can use the cflag of `-fsample-profile-use-profi`
instead of `-mllvm -sample-profile-use-profi`.

Reviewed By: hans, MaskRay

Differential Revision: https://reviews.llvm.org/D136846
This commit is contained in:
haoyuintel 2022-11-08 14:51:14 +08:00 committed by Phoebe Wang
parent 70c781f4b6
commit 13f83365cd
4 changed files with 26 additions and 0 deletions
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9
clang/docs/UsersManual.rst
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@ -2241,6 +2241,15 @@ usual build cycle when using sample profilers for optimization:
$ 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
""""""""""""""""""""""

7
clang/include/clang/Driver/Options.td
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@ -1251,6 +1251,13 @@ def fprofile_sample_accurate : Flag<["-"], "fprofile-sample-accurate">,
as cold. Otherwise, treat callsites without profile samples as if
we have no profile}]>,
MarshallingInfoFlag<CodeGenOpts<"ProfileSampleAccurate">>;
def fsample_profile_use_profi : Flag<["-"], "fsample-profile-use-profi">,
Flags<[NoXarchOption, CC1Option]>, Group<f_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<f_Group>, Flags<[NoXarchOption]>;
def fauto_profile : Flag<["-"], "fauto-profile">, Group<f_Group>,

6
clang/lib/Driver/ToolChains/Clang.cpp
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@ -5729,6 +5729,12 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
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)) {

4
clang/test/Driver/pgo-sample-use-profi.c Normal file
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@ -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"