From d90c50eaea792a051bc7b183067ca54c2c79a460 Mon Sep 17 00:00:00 2001
From: Dehao Chen <dehao@google.com>
Date: Thu, 19 Jan 2017 00:44:21 +0000
Subject: [PATCH] Add -fdebug-info-for-profiling to emit more debug info for
sample pgo profile collection
Summary:
SamplePGO uses profile with debug info to collect profile. Unlike the traditional debugging purpose, sample pgo needs more accurate debug info to represent the profile. We add -femit-accurate-debug-info for this purpose. It can be combined with all debugging modes (-g, -gmlt, etc). It makes sure that the following pieces of info is always emitted:
* start line of all subprograms
* linkage name of all subprograms
* standalone subprograms (functions that has neither inlined nor been inlined)
The impact on speccpu2006 binary size (size increase comparing with -g0 binary, also includes data for -g binary, which does not change with this patch):
-gmlt(orig) -gmlt(patched) -g
433.milc 4.68% 5.40% 19.73%
444.namd 8.45% 8.93% 45.99%
447.dealII 97.43% 115.21% 374.89%
450.soplex 27.75% 31.88% 126.04%
453.povray 21.81% 26.16% 92.03%
470.lbm 0.60% 0.67% 1.96%
482.sphinx3 5.77% 6.47% 26.17%
400.perlbench 17.81% 19.43% 73.08%
401.bzip2 3.73% 3.92% 12.18%
403.gcc 31.75% 34.48% 122.75%
429.mcf 0.78% 0.88% 3.89%
445.gobmk 6.08% 7.92% 42.27%
456.hmmer 10.36% 11.25% 35.23%
458.sjeng 5.08% 5.42% 14.36%
462.libquantum 1.71% 1.96% 6.36%
464.h264ref 15.61% 16.56% 43.92%
471.omnetpp 11.93% 15.84% 60.09%
473.astar 3.11% 3.69% 14.18%
483.xalancbmk 56.29% 81.63% 353.22%
geomean 15.60% 18.30% 57.81%
Debug info size change for -gmlt binary with this patch:
433.milc 13.46%
444.namd 5.35%
447.dealII 18.21%
450.soplex 14.68%
453.povray 19.65%
470.lbm 6.03%
482.sphinx3 11.21%
400.perlbench 8.91%
401.bzip2 4.41%
403.gcc 8.56%
429.mcf 8.24%
445.gobmk 29.47%
456.hmmer 8.19%
458.sjeng 6.05%
462.libquantum 11.23%
464.h264ref 5.93%
471.omnetpp 31.89%
473.astar 16.20%
483.xalancbmk 44.62%
geomean 16.83%
Reviewers: davidxl, andreadb, rob.lougher, dblaikie, echristo
Reviewed By: dblaikie, echristo
Subscribers: hfinkel, rob.lougher, andreadb, gbedwell, cfe-commits, probinson, llvm-commits, mehdi_amini
Differential Revision: https://reviews.llvm.org/D25435
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@292458 91177308-0d34-0410-b5e6-96231b3b80d8
---
include/clang/Driver/Options.td | 6 ++++++
include/clang/Frontend/CodeGenOptions.def | 3 +++
lib/CodeGen/BackendUtil.cpp | 1 +
lib/CodeGen/CGDebugInfo.cpp | 3 ++-
lib/Driver/Tools.cpp | 4 ++++
lib/Frontend/CompilerInvocation.cpp | 2 ++
test/Driver/clang_f_opts.c | 5 +++++
7 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index ecc34af44ef..af9e4a77ea2 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -516,6 +516,12 @@ def fprofile_sample_use_EQ : Joined<["-"], "fprofile-sample-use=">,
HelpText<"Enable sample-based profile guided optimizations">;
def fauto_profile_EQ : Joined<["-"], "fauto-profile=">,
Alias<fprofile_sample_use_EQ>;
+def fdebug_info_for_profiling : Flag<["-"], "fdebug-info-for-profiling">, Group<f_Group>,
+ Flags<[CC1Option]>,
+ HelpText<"Emit extra debug info to make sample profile more accurate.">;
+def fno_debug_info_for_profiling : Flag<["-"], "fno-debug-info-for-profiling">, Group<f_Group>,
+ Flags<[DriverOption]>,
+ HelpText<"Do not emit extra debug info for sample profiler.">;
def fprofile_instr_generate : Flag<["-"], "fprofile-instr-generate">,
Group<f_Group>, Flags<[CoreOption]>,
HelpText<"Generate instrumented code to collect execution counts into default.profraw file (overridden by '=' form of option or LLVM_PROFILE_FILE env var)">;
diff --git a/include/clang/Frontend/CodeGenOptions.def b/include/clang/Frontend/CodeGenOptions.def
index d4b2049d61f..0685b6613f3 100644
--- a/include/clang/Frontend/CodeGenOptions.def
+++ b/include/clang/Frontend/CodeGenOptions.def
@@ -258,6 +258,9 @@ CODEGENOPT(PIECopyRelocations, 1, 0)
/// paths that reach the end of a function without executing a required return.
CODEGENOPT(StrictReturn, 1, 1)
+/// Whether emit extra debug info for sample pgo profile collection.
+CODEGENOPT(DebugInfoForProfiling, 1, 0)
+
#undef CODEGENOPT
#undef ENUM_CODEGENOPT
#undef VALUE_CODEGENOPT
diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index 765c403fd15..bac1e89820a 100644
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -573,6 +573,7 @@ void EmitAssemblyHelper::CreateTargetMachine(bool MustCreateTM) {
Options.DisableIntegratedAS = CodeGenOpts.DisableIntegratedAS;
Options.CompressDebugSections = CodeGenOpts.CompressDebugSections;
Options.RelaxELFRelocations = CodeGenOpts.RelaxELFRelocations;
+ Options.DebugInfoForProfiling = CodeGenOpts.DebugInfoForProfiling;
// Set EABI version.
Options.EABIVersion = llvm::StringSwitch<llvm::EABI>(TargetOpts.EABIVersion)
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 12a68036b09..c3dd53f12e2 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -2774,9 +2774,10 @@ void CGDebugInfo::collectFunctionDeclProps(GlobalDecl GD, llvm::DIFile *Unit,
}
// No need to replicate the linkage name if it isn't different from the
// subprogram name, no need to have it at all unless coverage is enabled or
- // debug is set to more than just line tables.
+ // debug is set to more than just line tables or extra debug info is needed.
if (LinkageName == Name || (!CGM.getCodeGenOpts().EmitGcovArcs &&
!CGM.getCodeGenOpts().EmitGcovNotes &&
+ !CGM.getCodeGenOpts().DebugInfoForProfiling &&
DebugKind <= codegenoptions::DebugLineTablesOnly))
LinkageName = StringRef();
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index e7c6f22c95d..cb11f5d6f59 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -5615,6 +5615,10 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
A->render(Args, CmdArgs);
}
+ if (Args.hasFlag(options::OPT_fdebug_info_for_profiling,
+ options::OPT_fno_debug_info_for_profiling, false))
+ CmdArgs.push_back("-fdebug-info-for-profiling");
+
// -fbuiltin is default unless -mkernel is used.
bool UseBuiltins =
Args.hasFlag(options::OPT_fbuiltin, options::OPT_fno_builtin,
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 8256edd988e..7576d6d4e5e 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -544,6 +544,8 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
Opts.DisableIntegratedAS = Args.hasArg(OPT_fno_integrated_as);
Opts.Autolink = !Args.hasArg(OPT_fno_autolink);
Opts.SampleProfileFile = Args.getLastArgValue(OPT_fprofile_sample_use_EQ);
+ Opts.DebugInfoForProfiling = Args.hasFlag(
+ OPT_fdebug_info_for_profiling, OPT_fno_debug_info_for_profiling, false);
setPGOInstrumentor(Opts, Args, Diags);
Opts.InstrProfileOutput =
diff --git a/test/Driver/clang_f_opts.c b/test/Driver/clang_f_opts.c
index 210e16935d8..0261d93c49b 100644
--- a/test/Driver/clang_f_opts.c
+++ b/test/Driver/clang_f_opts.c
@@ -482,3 +482,8 @@
// RUN: %clang -### -S -fno-strict-return %s 2>&1 | FileCheck -check-prefix=CHECK-NO-STRICT-RETURN %s
// CHECK-STRICT-RETURN-NOT: "-fno-strict-return"
// CHECK-NO-STRICT-RETURN: "-fno-strict-return"
+
+// RUN: %clang -### -S -fno-debug-info-for-profiling -fdebug-info-for-profiling %s 2>&1 | FileCheck -check-prefix=CHECK-PROFILE-DEBUG %s
+// RUN: %clang -### -S -fdebug-info-for-profiling -fno-debug-info-for-profiling %s 2>&1 | FileCheck -check-prefix=CHECK-NO-PROFILE-DEBUG %s
+// CHECK-PROFILE-DEBUG: -fdebug-info-for-profiling
+// CHECK-NO-PROFILE-DEBUG-NOT: -fdebug-info-for-profiling
--
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