anemet created this revision.
anemet added reviewers: hfinkel, rjmccall, aaron.ballman.
anemet added a subscriber: cfe-commits.
I've recently added the ability for optimization remarks to include the
hotness of the corresponding code region. This uses PGO and allows
filtering of the optimization remarks by relevance. The idea was first
discussed here:
http://thread.gmane.org/gmane.comp.compilers.llvm.devel/98334
The general goal is to produce a YAML file with the remarks. Then, an
external tool could dynamically filter these by hotness and perhaps by
other things.
That said it makes sense to also expose this at the more basic level
where we just include the hotness info with each optimization remark.
For example, in D22694, the clang flag was pretty useful to measure the
overhead of the additional analyses required to include hotness.
(Without the flag we don't even run the analyses.)
For the record, Hal has already expressed support for the idea of this
patch on IRC.
I didn't make -R{,no-}pass-with-hotness member of Group<R_Group>.
I *think* that this is right because unlike other -Rpass flags this one
does not enable any remark group, so it shouldn't be processed by
ProcessWarningOptions.
https://reviews.llvm.org/D23284
Files:
include/clang/Basic/DiagnosticDriverKinds.td
include/clang/Driver/Options.td
include/clang/Frontend/CodeGenOptions.def
lib/CodeGen/CodeGenAction.cpp
lib/Frontend/CompilerInvocation.cpp
test/Frontend/Inputs/optimization-remark-with-hotness.proftext
test/Frontend/optimization-remark-with-hotness.c
Index: test/Frontend/optimization-remark-with-hotness.c
===================================================================
--- /dev/null
+++ test/Frontend/optimization-remark-with-hotness.c
@@ -0,0 +1,41 @@
+// RUN: llvm-profdata merge \
+// RUN: %S/Inputs/optimization-remark-with-hotness.proftext \
+// RUN: -o %t.profdata
+// 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 -Rpass-with-hotness -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: -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 -Rpass-with-hotness 2>&1 \
+// RUN: | FileCheck -check-prefix=NO_PGO %s
+
+int foo(int x, int y) __attribute__((always_inline));
+int foo(int x, int y) { return x + y; }
+
+int sum = 0;
+
+void bar(int x) {
+ // HOTNESS_OFF: foo inlined into bar
+ // HOTNESS_OFF-NOT: hotness:
+ // NO_PGO: '-Rpass-with-hotness' requires profile 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);
+}
+
+int main(int argc, const char *argv[]) {
+ for (int i = 0; i < 30; i++)
+ // expected-remark@+1 {{bar should never be inlined}}
+ bar(argc);
+ return sum;
+}
Index: test/Frontend/Inputs/optimization-remark-with-hotness.proftext
===================================================================
--- /dev/null
+++ test/Frontend/Inputs/optimization-remark-with-hotness.proftext
@@ -0,0 +1,25 @@
+foo
+# Func Hash:
+0
+# Num Counters:
+1
+# Counter Values:
+30
+
+bar
+# Func Hash:
+0
+# Num Counters:
+1
+# Counter Values:
+30
+
+main
+# Func Hash:
+4
+# Num Counters:
+2
+# Counter Values:
+1
+30
+
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -818,6 +818,14 @@
NeedLocTracking = true;
}
+ Opts.PassRemarksWithHotness =
+ Args.hasFlag(options::OPT_Rpass_with_hotness,
+ options::OPT_Rno_pass_with_hotness, /*default*/ false);
+ if (Opts.PassRemarksWithHotness &&
+ Opts.getProfileUse() == CodeGenOptions::ProfileNone)
+ Diags.Report(diag::warn_drv_argument_requires) << "-Rpass-with-hotness"
+ << "profile information";
+
// 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/CodeGen/CodeGenAction.cpp
===================================================================
--- lib/CodeGen/CodeGenAction.cpp
+++ lib/CodeGen/CodeGenAction.cpp
@@ -179,6 +179,7 @@
Ctx.getDiagnosticHandler();
void *OldDiagnosticContext = Ctx.getDiagnosticContext();
Ctx.setDiagnosticHandler(DiagnosticHandler, this);
+ Ctx.setDiagnosticHotnessRequested(CodeGenOpts.PassRemarksWithHotness);
// Link LinkModule into this module if present, preserving its validity.
for (auto &I : LinkModules) {
@@ -511,9 +512,16 @@
FullSourceLoc Loc = getBestLocationFromDebugLoc(D, BadDebugInfo, Filename,
Line, Column);
+ std::string Msg;
+ raw_string_ostream MsgStream(Msg);
+ MsgStream << D.getMsg().str();
+
+ if (D.getHotness())
+ MsgStream << " (hotness: " << *D.getHotness() << ")";
+
Diags.Report(Loc, DiagID)
<< AddFlagValue(D.getPassName() ? D.getPassName() : "")
- << D.getMsg().str();
+ << MsgStream.str();
if (BadDebugInfo)
// If we were not able to translate the file:line:col information
Index: include/clang/Frontend/CodeGenOptions.def
===================================================================
--- include/clang/Frontend/CodeGenOptions.def
+++ include/clang/Frontend/CodeGenOptions.def
@@ -237,6 +237,9 @@
/// filename)
VALUE_CODEGENOPT(EmitCheckPathComponentsToStrip, 32, 0)
+/// Whether to report the hotness of the code region for optimization remarks.
+CODEGENOPT(PassRemarksWithHotness, 1, 0)
+
#undef CODEGENOPT
#undef ENUM_CODEGENOPT
#undef VALUE_CODEGENOPT
Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -303,6 +303,12 @@
"name matches the given POSIX regular expression">;
def R_Joined : Joined<["-"], "R">, Group<R_Group>, Flags<[CC1Option, CoreOption]>,
MetaVarName<"<remark>">, HelpText<"Enable the specified remark">;
+// Don't include in R_Group, since this does not enable any remark group.
+def Rpass_with_hotness : Flag<["-"], "Rpass-with-hotness">, Flags<[CC1Option]>,
+ HelpText<"If profile-guided optimization information is available, "
+ "include hotness of transformed code region in messages "
+ "reported by -Rpass* options">;
+def Rno_pass_with_hotness : Flag<["-"], "Rno-pass-with-hotness">, Flags<[CC1Option]>;
def S : Flag<["-"], "S">, Flags<[DriverOption,CC1Option]>, Group<Action_Group>,
HelpText<"Only run preprocess and compilation steps">;
def Tbss : JoinedOrSeparate<["-"], "Tbss">, Group<T_Group>;
Index: include/clang/Basic/DiagnosticDriverKinds.td
===================================================================
--- include/clang/Basic/DiagnosticDriverKinds.td
+++ include/clang/Basic/DiagnosticDriverKinds.td
@@ -182,6 +182,9 @@
def warn_drv_empty_joined_argument : Warning<
"joined argument expects additional value: '%0'">,
InGroup<UnusedCommandLineArgument>;
+def warn_drv_argument_requires : Warning<
+ "argument '%0' requires %1">,
+ InGroup<UnusedCommandLineArgument>;
def warn_drv_clang_unsupported : Warning<
"the clang compiler does not support '%0'">;
def warn_drv_deprecated_arg : Warning<
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
