llvm-project/llvm/unittests/IR/ModuleTest.cpp
Hiroshi Yamauchi 6c27c61d32 [PGO] Improve the working set size heuristics under the partial sample PGO.
Summary:
The working set size heuristics (ProfileSummaryInfo::hasHugeWorkingSetSize)
under the partial sample PGO may not be accurate because the profile is partial
and the number of hot profile counters in the ProfileSummary may not reflect the
actual working set size of the program being compiled.

To improve this, the (approximated) ratio of the the number of profile counters
of the program being compiled to the number of profile counters in the partial
sample profile is computed (which is called the partial profile ratio) and the
working set size of the profile is scaled by this ratio to reflect the working
set size of the program being compiled and used for the working set size
heuristics.

The partial profile ratio is approximated based on the number of the basic
blocks in the program and the NumCounts field in the ProfileSummary and computed
through the thin LTO indexing. This means that there is the limitation that the
scaled working set size is available to the thin LTO post link passes only.

Reviewers: davidxl

Subscribers: mgorny, eraman, hiraditya, steven_wu, dexonsmith, arphaman, dang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79831
2020-06-01 10:29:23 -07:00

162 lines
5.3 KiB
C++

//===- unittests/IR/ModuleTest.cpp - Module unit tests --------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/IR/Module.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/Pass.h"
#include "llvm/Support/RandomNumberGenerator.h"
#include "gtest/gtest.h"
#include <random>
using namespace llvm;
namespace {
bool sortByName(const GlobalVariable &L, const GlobalVariable &R) {
return L.getName() < R.getName();
}
bool sortByNameReverse(const GlobalVariable &L, const GlobalVariable &R) {
return sortByName(R, L);
}
TEST(ModuleTest, sortGlobalsByName) {
LLVMContext Context;
for (auto compare : {&sortByName, &sortByNameReverse}) {
Module M("M", Context);
Type *T = Type::getInt8Ty(Context);
GlobalValue::LinkageTypes L = GlobalValue::ExternalLinkage;
(void)new GlobalVariable(M, T, false, L, nullptr, "A");
(void)new GlobalVariable(M, T, false, L, nullptr, "F");
(void)new GlobalVariable(M, T, false, L, nullptr, "G");
(void)new GlobalVariable(M, T, false, L, nullptr, "E");
(void)new GlobalVariable(M, T, false, L, nullptr, "B");
(void)new GlobalVariable(M, T, false, L, nullptr, "H");
(void)new GlobalVariable(M, T, false, L, nullptr, "C");
(void)new GlobalVariable(M, T, false, L, nullptr, "D");
// Sort the globals by name.
EXPECT_FALSE(std::is_sorted(M.global_begin(), M.global_end(), compare));
M.getGlobalList().sort(compare);
EXPECT_TRUE(std::is_sorted(M.global_begin(), M.global_end(), compare));
}
}
TEST(ModuleTest, randomNumberGenerator) {
LLVMContext Context;
static char ID;
struct DummyPass : ModulePass {
DummyPass() : ModulePass(ID) {}
bool runOnModule(Module &) { return true; }
} DP;
Module M("R", Context);
std::uniform_int_distribution<int> dist;
const size_t NBCheck = 10;
std::array<int, NBCheck> RandomStreams[2];
for (auto &RandomStream : RandomStreams) {
std::unique_ptr<RandomNumberGenerator> RNG = M.createRNG(DP.getPassName());
std::generate(RandomStream.begin(), RandomStream.end(),
[&]() { return dist(*RNG); });
}
EXPECT_TRUE(std::equal(RandomStreams[0].begin(), RandomStreams[0].end(),
RandomStreams[1].begin()));
}
TEST(ModuleTest, setModuleFlag) {
LLVMContext Context;
Module M("M", Context);
StringRef Key = "Key";
Metadata *Val1 = MDString::get(Context, "Val1");
Metadata *Val2 = MDString::get(Context, "Val2");
EXPECT_EQ(nullptr, M.getModuleFlag(Key));
M.setModuleFlag(Module::ModFlagBehavior::Error, Key, Val1);
EXPECT_EQ(Val1, M.getModuleFlag(Key));
M.setModuleFlag(Module::ModFlagBehavior::Error, Key, Val2);
EXPECT_EQ(Val2, M.getModuleFlag(Key));
}
const char *IRString = R"IR(
!llvm.module.flags = !{!0}
!0 = !{i32 1, !"ProfileSummary", !1}
!1 = !{!2, !3, !4, !5, !6, !7, !8, !9}
!2 = !{!"ProfileFormat", !"SampleProfile"}
!3 = !{!"TotalCount", i64 10000}
!4 = !{!"MaxCount", i64 10}
!5 = !{!"MaxInternalCount", i64 1}
!6 = !{!"MaxFunctionCount", i64 1000}
!7 = !{!"NumCounts", i64 200}
!8 = !{!"NumFunctions", i64 3}
!9 = !{!"DetailedSummary", !10}
!10 = !{!11, !12, !13}
!11 = !{i32 10000, i64 1000, i32 1}
!12 = !{i32 990000, i64 300, i32 10}
!13 = !{i32 999999, i64 5, i32 100}
)IR";
TEST(ModuleTest, setProfileSummary) {
SMDiagnostic Err;
LLVMContext Context;
std::unique_ptr<Module> M = parseAssemblyString(IRString, Err, Context);
auto *PS = ProfileSummary::getFromMD(M->getProfileSummary(/*IsCS*/ false));
EXPECT_NE(nullptr, PS);
EXPECT_EQ(false, PS->isPartialProfile());
PS->setPartialProfile(true);
M->setProfileSummary(PS->getMD(Context), ProfileSummary::PSK_Sample);
delete PS;
PS = ProfileSummary::getFromMD(M->getProfileSummary(/*IsCS*/ false));
EXPECT_NE(nullptr, PS);
EXPECT_EQ(true, PS->isPartialProfile());
delete PS;
}
TEST(ModuleTest, setPartialSampleProfileRatio) {
const char *IRString = R"IR(
!llvm.module.flags = !{!0}
!0 = !{i32 1, !"ProfileSummary", !1}
!1 = !{!2, !3, !4, !5, !6, !7, !8, !9, !10, !11}
!2 = !{!"ProfileFormat", !"SampleProfile"}
!3 = !{!"TotalCount", i64 10000}
!4 = !{!"MaxCount", i64 10}
!5 = !{!"MaxInternalCount", i64 1}
!6 = !{!"MaxFunctionCount", i64 1000}
!7 = !{!"NumCounts", i64 200}
!8 = !{!"NumFunctions", i64 3}
!9 = !{!"IsPartialProfile", i64 1}
!10 = !{!"PartialProfileRatio", double 0.0}
!11 = !{!"DetailedSummary", !12}
!12 = !{!13, !14, !15}
!13 = !{i32 10000, i64 1000, i32 1}
!14 = !{i32 990000, i64 300, i32 10}
!15 = !{i32 999999, i64 5, i32 100}
)IR";
SMDiagnostic Err;
LLVMContext Context;
std::unique_ptr<Module> M = parseAssemblyString(IRString, Err, Context);
ModuleSummaryIndex Index(/*HaveGVs*/ false);
const unsigned BlockCount = 100;
const unsigned NumCounts = 200;
Index.setBlockCount(BlockCount);
M->setPartialSampleProfileRatio(Index);
double Ratio = (double)BlockCount / NumCounts;
std::unique_ptr<ProfileSummary> ProfileSummary(
ProfileSummary::getFromMD(M->getProfileSummary(/*IsCS*/ false)));
EXPECT_EQ(Ratio, ProfileSummary->getPartialProfileRatio());
}
} // end namespace