modocache created this revision.
Herald added a subscriber: fhahn.
Depends on https://reviews.llvm.org/D34867.
Add a Clang frontend option to enable optimization remark hotness
thresholds, which were added to LLVM in https://reviews.llvm.org/D34867.
This prevents diagnostics that do not meet a minimum hotness
threshold from being output. When generating optimization remarks for large
codebases with a ton of cold code paths, this option can be used
to limit the optimization remark output at a reasonable size.
Discussion of this change can be read here:
http://lists.llvm.org/pipermail/llvm-dev/2017-June/114377.html
https://reviews.llvm.org/D34868
Files:
docs/UsersManual.rst
include/clang/Basic/DiagnosticDriverKinds.td
include/clang/Driver/Options.td
include/clang/Frontend/CodeGenOptions.def
lib/CodeGen/CodeGenAction.cpp
lib/Driver/ToolChains/Clang.cpp
lib/Frontend/CompilerInvocation.cpp
test/Frontend/Inputs/optimization-remark-with-hotness-sample.proftext
test/Frontend/optimization-remark-with-hotness.c
Index: test/Frontend/optimization-remark-with-hotness.c
===================================================================
--- test/Frontend/optimization-remark-with-hotness.c
+++ test/Frontend/optimization-remark-with-hotness.c
@@ -10,29 +10,39 @@
// RUN: optimization-remark-with-hotness.c %s -emit-llvm-only \
// RUN: -fprofile-instrument-use-path=%t.profdata -Rpass=inline \
// RUN: -Rpass-analysis=inline -Rpass-missed=inline \
-// RUN: -fdiagnostics-show-hotness -verify
+// RUN: -fdiagnostics-show-hotness -fdiagnostics-hotness-threshold=10 \
+// RUN: -verify
// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name \
// RUN: optimization-remark-with-hotness.c %s -emit-llvm-only \
// RUN: -fprofile-sample-use=%t-sample.profdata -Rpass=inline \
// RUN: -Rpass-analysis=inline -Rpass-missed=inline \
-// RUN: -fdiagnostics-show-hotness -verify
+// RUN: -fdiagnostics-show-hotness -fdiagnostics-hotness-threshold=10 \
+// RUN: -verify
// The clang version of the previous test.
// RUN: %clang -target x86_64-apple-macosx10.9 %s -c -emit-llvm -o /dev/null \
// RUN: -fprofile-instr-use=%t.profdata -Rpass=inline \
// RUN: -Rpass-analysis=inline -Rpass-missed=inline \
-// RUN: -fdiagnostics-show-hotness -Xclang -verify
+// RUN: -fdiagnostics-show-hotness -fdiagnostics-hotness-threshold=10 \
+// RUN: -Xclang -verify
// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name \
// RUN: optimization-remark-with-hotness.c %s -emit-llvm-only \
// RUN: -fprofile-instrument-use-path=%t.profdata -Rpass=inline \
// RUN: -Rpass-analysis=inline 2>&1 | FileCheck -check-prefix=HOTNESS_OFF %s
// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name \
// RUN: optimization-remark-with-hotness.c %s -emit-llvm-only \
// RUN: -fprofile-instrument-use-path=%t.profdata -Rpass=inline \
-// RUN: -Rpass-analysis=inline -Rno-pass-with-hotness 2>&1 | FileCheck \
+// RUN: -Rpass-analysis=inline -Rno-pass-with-hotness 2>&1 | FileCheck \
// RUN: -check-prefix=HOTNESS_OFF %s
// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name \
// RUN: optimization-remark-with-hotness.c %s -emit-llvm-only \
-// RUN: -Rpass=inline -Rpass-analysis=inline -fdiagnostics-show-hotness 2>&1 \
+// RUN: -fprofile-instrument-use-path=%t.profdata -Rpass=inline \
+// RUN: -Rpass-analysis=inline -fdiagnostics-show-hotness \
+// RUN: -fdiagnostics-hotness-threshold=100 2>&1 \
+// RUN: | FileCheck -allow-empty -check-prefix=THRESHOLD %s
+// RUN: %clang_cc1 -triple x86_64-apple-macosx10.9 -main-file-name \
+// RUN: optimization-remark-with-hotness.c %s -emit-llvm-only \
+// RUN: -Rpass=inline -Rpass-analysis=inline \
+// RUN: -fdiagnostics-show-hotness -fdiagnostics-hotness-threshold=10 2>&1 \
// RUN: | FileCheck -check-prefix=NO_PGO %s
int foo(int x, int y) __attribute__((always_inline));
@@ -43,7 +53,10 @@
void bar(int x) {
// HOTNESS_OFF: foo inlined into bar
// HOTNESS_OFF-NOT: hotness:
+ // THRESHOLD-NOT: inlined
+ // THRESHOLD-NOT: hotness
// NO_PGO: '-fdiagnostics-show-hotness' requires profile-guided optimization information
+ // NO_PGO: '-fdiagnostics-hotness-threshold=' requires profile-guided optimization information
// expected-remark@+2 {{foo should always be inlined (cost=always) (hotness: 30)}}
// expected-remark@+1 {{foo inlined into bar (hotness: 30)}}
sum += foo(x, x - 2);
Index: test/Frontend/Inputs/optimization-remark-with-hotness-sample.proftext
===================================================================
--- test/Frontend/Inputs/optimization-remark-with-hotness-sample.proftext
+++ test/Frontend/Inputs/optimization-remark-with-hotness-sample.proftext
@@ -1,7 +1,7 @@
foo:0:0
0: 0
bar:29:29
- 6: foo:0
+ 9: foo:0
main:0:0
0: 0 bar:0
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -906,13 +906,19 @@
Opts.DiagnosticsWithHotness =
Args.hasArg(options::OPT_fdiagnostics_show_hotness);
bool UsingSampleProfile = !Opts.SampleProfileFile.empty();
+ bool UsingProfile = UsingSampleProfile ||
+ (Opts.getProfileUse() != CodeGenOptions::ProfileNone);
- if (Opts.DiagnosticsWithHotness &&
- Opts.getProfileUse() == CodeGenOptions::ProfileNone &&
- !UsingSampleProfile) {
+ if (Opts.DiagnosticsWithHotness && !UsingProfile) {
Diags.Report(diag::warn_drv_fdiagnostics_show_hotness_requires_pgo);
}
+ Opts.DiagnosticsHotnessThreshold = getLastArgUInt64Value(
+ Args, options::OPT_fdiagnostics_hotness_threshold_EQ, 0);
+ if (Opts.DiagnosticsHotnessThreshold > 0 && !UsingProfile) {
+ Diags.Report(diag::warn_drv_fdiagnostics_hotness_threshold_requires_pgo);
+ }
+
// If the user requested to use a sample profile for PGO, then the
// backend will need to track source location information so the profile
// can be incorporated into the IR.
Index: lib/Driver/ToolChains/Clang.cpp
===================================================================
--- lib/Driver/ToolChains/Clang.cpp
+++ lib/Driver/ToolChains/Clang.cpp
@@ -4072,6 +4072,12 @@
options::OPT_fno_diagnostics_show_hotness, false))
CmdArgs.push_back("-fdiagnostics-show-hotness");
+ if (const Arg *A =
+ Args.getLastArg(options::OPT_fdiagnostics_hotness_threshold_EQ)) {
+ std::string Opt = std::string("-fdiagnostics-hotness-threshold=") + A->getValue();
+ CmdArgs.push_back(Args.MakeArgString(Opt));
+ }
+
if (const Arg *A = Args.getLastArg(options::OPT_fdiagnostics_format_EQ)) {
CmdArgs.push_back("-fdiagnostics-format");
CmdArgs.push_back(A->getValue());
Index: lib/CodeGen/CodeGenAction.cpp
===================================================================
--- lib/CodeGen/CodeGenAction.cpp
+++ lib/CodeGen/CodeGenAction.cpp
@@ -229,6 +229,10 @@
void *OldDiagnosticContext = Ctx.getDiagnosticContext();
Ctx.setDiagnosticHandler(DiagnosticHandler, this);
Ctx.setDiagnosticsHotnessRequested(CodeGenOpts.DiagnosticsWithHotness);
+ if (CodeGenOpts.DiagnosticsHotnessThreshold != 0) {
+ Ctx.setDiagnosticsHotnessThreshold(
+ CodeGenOpts.DiagnosticsHotnessThreshold);
+ }
std::unique_ptr<llvm::tool_output_file> OptRecordFile;
if (!CodeGenOpts.OptRecordFile.empty()) {
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -260,6 +260,10 @@
/// Whether to report the hotness of the code region for optimization remarks.
CODEGENOPT(DiagnosticsWithHotness, 1, 0)
+/// The minimum hotness value a diagnostic needs in order to be included in
+/// optimization diagnostics.
+VALUE_CODEGENOPT(DiagnosticsHotnessThreshold, 32, 0)
+
/// Whether copy relocations support is available when building as PIE.
CODEGENOPT(PIECopyRelocations, 1, 0)
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -723,6 +723,9 @@
HelpText<"Print source range spans in numeric form">;
def fdiagnostics_show_hotness : Flag<["-"], "fdiagnostics-show-hotness">, Group<f_Group>,
Flags<[CC1Option]>, HelpText<"Enable profile hotness information in diagnostic line">;
+def fdiagnostics_hotness_threshold_EQ : Joined<["-"], "fdiagnostics-hotness-threshold=">,
+ Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<number>">,
+ HelpText<"Prevent optimization remarks from being output if they do not have at least this hotness value">;
def fdiagnostics_show_option : Flag<["-"], "fdiagnostics-show-option">, Group<f_Group>,
Flags<[CC1Option]>, HelpText<"Print option name with mappable diagnostics">;
def fdiagnostics_show_note_include_stack : Flag<["-"], "fdiagnostics-show-note-include-stack">,
Index: include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- include/clang/Basic/DiagnosticDriverKinds.td
+++ include/clang/Basic/DiagnosticDriverKinds.td
@@ -198,6 +198,9 @@
def warn_drv_fdiagnostics_show_hotness_requires_pgo : Warning<
"argument '-fdiagnostics-show-hotness' requires profile-guided optimization information">,
InGroup<UnusedCommandLineArgument>;
+def warn_drv_fdiagnostics_hotness_threshold_requires_pgo : Warning<
+ "argument '-fdiagnostics-hotness-threshold=' requires profile-guided optimization information">,
+ InGroup<UnusedCommandLineArgument>;
def warn_drv_clang_unsupported : Warning<
"the clang compiler does not support '%0'">;
def warn_drv_deprecated_arg : Warning<
Index: docs/UsersManual.rst
===================================================================
--- docs/UsersManual.rst
+++ docs/UsersManual.rst
@@ -344,6 +344,19 @@
sum += foo(x, x - 2);
^
+.. _opt_fdiagnostics-hotness-threshold
+
+**-fdiagnostics-hotness-threshold**
+ Prevent optimization remarks from being output if they do not have at least
+ this hotness value.
+
+ This option, which defaults to zero, controls the minimum hotness an
+ optimization remark would need in order to be output by Clang. This is
+ currently supported with optimization remarks (see :ref:`Options to Emit
+ Optimization Reports <rpass>`) when profile hotness information in
+ diagnostics is enabled (see
+ :ref:`-fdiagnostics-show-hotness <opt_fdiagnostics-show-hotness>`).
+
.. _opt_fdiagnostics-fixit-info:
**-f[no-]diagnostics-fixit-info**
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