[llvm] r328909 - [ThinLTO] Add an option to force summary call edges cold for debugging
Teresa Johnson via llvm-commits
llvm-commits at lists.llvm.org
Fri Mar 30 17:18:08 PDT 2018
Author: tejohnson
Date: Fri Mar 30 17:18:08 2018
New Revision: 328909
URL: http://llvm.org/viewvc/llvm-project?rev=328909&view=rev
Log:
[ThinLTO] Add an option to force summary call edges cold for debugging
Summary:
Useful to selectively disable importing into specific modules for
debugging/triaging/workarounds.
Reviewers: eraman
Subscribers: inglorion, llvm-commits
Differential Revision: https://reviews.llvm.org/D45062
Added:
llvm/trunk/test/Transforms/FunctionImport/Inputs/funcimport_forcecold.ll
llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold.ll
llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold_samplepgo.ll
Modified:
llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp
llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
Modified: llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h?rev=328909&r1=328908&r2=328909&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h (original)
+++ llvm/trunk/include/llvm/IR/ModuleSummaryIndex.h Fri Mar 30 17:18:08 2018
@@ -404,6 +404,13 @@ public:
/// <CalleeValueInfo, CalleeInfo> call edge pair.
using EdgeTy = std::pair<ValueInfo, CalleeInfo>;
+ /// Types for -force-summary-edges-cold debugging option.
+ enum ForceSummaryHotnessType : unsigned {
+ FSHT_None,
+ FSHT_AllNonCritical,
+ FSHT_All
+ };
+
/// An "identifier" for a virtual function. This contains the type identifier
/// represented as a GUID and the offset from the address point to the virtual
/// function pointer, where "address point" is as defined in the Itanium ABI:
Modified: llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp?rev=328909&r1=328908&r2=328909&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp Fri Mar 30 17:18:08 2018
@@ -49,6 +49,7 @@
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
@@ -58,6 +59,18 @@ using namespace llvm;
#define DEBUG_TYPE "module-summary-analysis"
+// Option to force edges cold which will block importing when the
+// -import-cold-multiplier is set to 0. Useful for debugging.
+FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold =
+ FunctionSummary::FSHT_None;
+cl::opt<FunctionSummary::ForceSummaryHotnessType, true> FSEC(
+ "force-summary-edges-cold", cl::Hidden, cl::location(ForceSummaryEdgesCold),
+ cl::desc("Force all edges in the function summary to cold"),
+ cl::values(clEnumValN(FunctionSummary::FSHT_None, "none", "None."),
+ clEnumValN(FunctionSummary::FSHT_AllNonCritical,
+ "all-non-critical", "All non-critical edges."),
+ clEnumValN(FunctionSummary::FSHT_All, "all", "All edges.")));
+
// Walk through the operands of a given User via worklist iteration and populate
// the set of GlobalValue references encountered. Invoked either on an
// Instruction or a GlobalVariable (which walks its initializer).
@@ -268,6 +281,8 @@ computeFunctionSummary(ModuleSummaryInde
auto ScaledCount = PSI->getProfileCount(&I, BFI);
auto Hotness = ScaledCount ? getHotness(ScaledCount.getValue(), PSI)
: CalleeInfo::HotnessType::Unknown;
+ if (ForceSummaryEdgesCold != FunctionSummary::FSHT_None)
+ Hotness = CalleeInfo::HotnessType::Cold;
// Use the original CalledValue, in case it was an alias. We want
// to record the call edge to the alias in that case. Eventually
@@ -318,7 +333,9 @@ computeFunctionSummary(ModuleSummaryInde
// sample PGO, to enable the same inlines as the profiled optimized binary.
for (auto &I : F.getImportGUIDs())
CallGraphEdges[Index.getOrInsertValueInfo(I)].updateHotness(
- CalleeInfo::HotnessType::Critical);
+ ForceSummaryEdgesCold == FunctionSummary::FSHT_All
+ ? CalleeInfo::HotnessType::Cold
+ : CalleeInfo::HotnessType::Critical);
bool NonRenamableLocal = isNonRenamableLocal(F);
bool NotEligibleForImport =
Modified: llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp?rev=328909&r1=328908&r2=328909&view=diff
==============================================================================
--- llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp (original)
+++ llvm/trunk/lib/Bitcode/Writer/BitcodeWriter.cpp Fri Mar 30 17:18:08 2018
@@ -89,6 +89,9 @@ static cl::opt<unsigned>
cl::opt<bool> WriteRelBFToSummary(
"write-relbf-to-summary", cl::Hidden, cl::init(false),
cl::desc("Write relative block frequency to function summary "));
+
+extern FunctionSummary::ForceSummaryHotnessType ForceSummaryEdgesCold;
+
namespace {
/// These are manifest constants used by the bitcode writer. They do not need to
@@ -3436,7 +3439,8 @@ void ModuleBitcodeWriterBase::writePerMo
for (auto &RI : FS->refs())
NameVals.push_back(VE.getValueID(RI.getValue()));
- bool HasProfileData = F.hasProfileData();
+ bool HasProfileData =
+ F.hasProfileData() || ForceSummaryEdgesCold != FunctionSummary::FSHT_None;
for (auto &ECI : FS->calls()) {
NameVals.push_back(getValueId(ECI.first));
if (HasProfileData)
Added: llvm/trunk/test/Transforms/FunctionImport/Inputs/funcimport_forcecold.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionImport/Inputs/funcimport_forcecold.ll?rev=328909&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/FunctionImport/Inputs/funcimport_forcecold.ll (added)
+++ llvm/trunk/test/Transforms/FunctionImport/Inputs/funcimport_forcecold.ll Fri Mar 30 17:18:08 2018
@@ -0,0 +1,4 @@
+define void @foo() {
+entry:
+ ret void
+}
Added: llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold.ll?rev=328909&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold.ll (added)
+++ llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold.ll Fri Mar 30 17:18:08 2018
@@ -0,0 +1,36 @@
+; Test to ensure that building summary with -force-summary-edges-cold
+; blocks importing as expected.
+
+; "-stats" and "-debug-only" require +Asserts.
+; REQUIRES: asserts
+
+; First do with default options, which should import
+; RUN: opt -module-summary %s -o %t.bc
+; RUN: opt -module-summary %p/Inputs/funcimport_forcecold.ll -o %t2.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=IMPORT
+
+; Next rebuild caller module summary with non-critical edges forced cold (which
+; should affect all edges in this test as we don't have any sample pgo).
+; Make sure we don't import.
+; RUN: opt -force-summary-edges-cold=all-non-critical -module-summary %s -o %t.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=NOIMPORT
+
+; Next rebuild caller module summary with all edges forced cold.
+; Make sure we don't import.
+; RUN: opt -force-summary-edges-cold=all -module-summary %s -o %t.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=NOIMPORT
+
+define i32 @main() {
+entry:
+ call void @foo()
+ ret i32 0
+}
+
+; IMPORT: Import foo
+; NOIMPORT-NOT: Import foo
+; IMPORT: define available_externally void @foo()
+; NOIMPORT: declare void @foo()
+declare void @foo()
Added: llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold_samplepgo.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold_samplepgo.ll?rev=328909&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold_samplepgo.ll (added)
+++ llvm/trunk/test/Transforms/FunctionImport/funcimport_forcecold_samplepgo.ll Fri Mar 30 17:18:08 2018
@@ -0,0 +1,37 @@
+; Test to ensure that building summary with -force-summary-edges-cold
+; blocks importing as expected.
+
+; "-stats" and "-debug-only" require +Asserts.
+; REQUIRES: asserts
+
+; First do with default options, which should import
+; RUN: opt -module-summary %s -o %t.bc
+; RUN: opt -module-summary %p/Inputs/funcimport_forcecold.ll -o %t2.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=IMPORT
+
+; Next rebuild caller module summary with only non-critical edges forced cold,
+; which should still import in this case.
+; RUN: opt -force-summary-edges-cold=all-non-critical -module-summary %s -o %t.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=IMPORT
+
+; Next rebuild caller module summary with all edges forced cold.
+; Make sure we don't import.
+; RUN: opt -force-summary-edges-cold=all -module-summary %s -o %t.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+; RUN: opt -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=NOIMPORT
+
+define i32 @main() !prof !1 {
+entry:
+ call void @foo()
+ ret i32 0
+}
+
+; IMPORT: Import foo
+; NOIMPORT-NOT: Import foo
+; IMPORT: define available_externally void @foo()
+; NOIMPORT: declare void @foo()
+declare void @foo()
+
+!1 = !{!"function_entry_count", i64 110, i64 6699318081062747564}
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