<div dir="ltr">Hello, this change seems to be causing some LeakSanitizer test failures, e.g. <a href="http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/10962/steps/check-llvm%20asan/logs/stdio">http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/10962/steps/check-llvm%20asan/logs/stdio</a><br><br><div class="gmail_quote"><div dir="ltr">On Tue, Dec 5, 2017 at 9:20 AM Xinliang David Li via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org">llvm-commits@lists.llvm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: davidxl<br>
Date: Tue Dec 5 09:19:41 2017<br>
New Revision: 319794<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=319794&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project?rev=319794&view=rev</a><br>
Log:<br>
[PGO] detect infinite loop and form MST properly<br>
<br>
Differential Revision: <a href="http://reviews.llvm.org/D40702" rel="noreferrer" target="_blank">http://reviews.llvm.org/D40702</a><br>
<br>
Added:<br>
llvm/trunk/test/Transforms/PGOProfile/infinite_loop_gen.ll<br>
Modified:<br>
llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h<br>
llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp<br>
<br>
Modified: llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h?rev=319794&r1=319793&r2=319794&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h?rev=319794&r1=319793&r2=319794&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h (original)<br>
+++ llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h Tue Dec 5 09:19:41 2017<br>
@@ -20,6 +20,7 @@<br>
#include "llvm/Analysis/BlockFrequencyInfo.h"<br>
#include "llvm/Analysis/BranchProbabilityInfo.h"<br>
#include "llvm/Analysis/CFG.h"<br>
+#include "llvm/Analysis/LoopInfo.h"<br>
#include "llvm/Support/BranchProbability.h"<br>
#include "llvm/Support/Debug.h"<br>
#include "llvm/Support/raw_ostream.h"<br>
@@ -136,6 +137,21 @@ public:<br>
<< " w = " << BBWeight << "\n");<br>
}<br>
}<br>
+ // check if there is any infinite loop. If yes, add a fake edge from<br>
+ // the header block to the fake node:<br>
+ for (auto *L : *LI) {<br>
+ SmallVector<BasicBlock *, 2> ExitingBlocks;<br>
+ L->getExitingBlocks(ExitingBlocks);<br>
+ if (!ExitingBlocks.empty())<br>
+ continue;<br>
+ auto *HB = L->getHeader();<br>
+ if (!HB)<br>
+ continue;<br>
+ addEdge(HB, nullptr, UINT64_MAX);<br>
+ DEBUG(dbgs() << " Edge: from infinite loop header "<br>
+ << HB->getName() << " to exit"<br>
+ << " w = " << UINT64_MAX << "\n");<br>
+ }<br>
}<br>
<br>
// Sort CFG edges based on its weight.<br>
@@ -212,11 +228,13 @@ public:<br>
<br>
BranchProbabilityInfo *BPI;<br>
BlockFrequencyInfo *BFI;<br>
+ LoopInfo *LI;<br>
<br>
public:<br>
CFGMST(Function &Func, BranchProbabilityInfo *BPI_ = nullptr,<br>
- BlockFrequencyInfo *BFI_ = nullptr)<br>
- : F(Func), BPI(BPI_), BFI(BFI_) {<br>
+ BlockFrequencyInfo *BFI_ = nullptr,<br>
+ LoopInfo *LI_ = nullptr)<br>
+ : F(Func), BPI(BPI_), BFI(BFI_), LI(LI_) {<br>
buildEdges();<br>
sortEdgesByWeight();<br>
computeMinimumSpanningTree();<br>
<br>
Modified: llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp?rev=319794&r1=319793&r2=319794&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp?rev=319794&r1=319793&r2=319794&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (original)<br>
+++ llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp Tue Dec 5 09:19:41 2017<br>
@@ -390,6 +390,7 @@ private:<br>
<br>
void getAnalysisUsage(AnalysisUsage &AU) const override {<br>
AU.addRequired<BlockFrequencyInfoWrapperPass>();<br>
+ AU.addRequired<LoopInfoWrapperPass>();<br>
}<br>
};<br>
<br>
@@ -415,6 +416,7 @@ private:<br>
<br>
void getAnalysisUsage(AnalysisUsage &AU) const override {<br>
AU.addRequired<BlockFrequencyInfoWrapperPass>();<br>
+ AU.addRequired<LoopInfoWrapperPass>();<br>
}<br>
};<br>
<br>
@@ -426,6 +428,7 @@ INITIALIZE_PASS_BEGIN(PGOInstrumentation<br>
"PGO instrumentation.", false, false)<br>
INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)<br>
INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfoWrapperPass)<br>
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)<br>
INITIALIZE_PASS_END(PGOInstrumentationGenLegacyPass, "pgo-instr-gen",<br>
"PGO instrumentation.", false, false)<br>
<br>
@@ -439,6 +442,7 @@ INITIALIZE_PASS_BEGIN(PGOInstrumentation<br>
"Read PGO instrumentation profile.", false, false)<br>
INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)<br>
INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfoWrapperPass)<br>
+INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)<br>
INITIALIZE_PASS_END(PGOInstrumentationUseLegacyPass, "pgo-instr-use",<br>
"Read PGO instrumentation profile.", false, false)<br>
<br>
@@ -530,9 +534,9 @@ public:<br>
Function &Func,<br>
std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers,<br>
bool CreateGlobalVar = false, BranchProbabilityInfo *BPI = nullptr,<br>
- BlockFrequencyInfo *BFI = nullptr)<br>
+ BlockFrequencyInfo *BFI = nullptr, LoopInfo *LI = nullptr)<br>
: F(Func), ComdatMembers(ComdatMembers), ValueSites(IPVK_Last + 1),<br>
- SIVisitor(Func), MIVisitor(Func), MST(F, BPI, BFI) {<br>
+ SIVisitor(Func), MIVisitor(Func), MST(F, BPI, BFI, LI) {<br>
// This should be done before CFG hash computation.<br>
SIVisitor.countSelects(Func);<br>
MIVisitor.countMemIntrinsics(Func);<br>
@@ -715,9 +719,10 @@ BasicBlock *FuncPGOInstrumentation<Edge,<br>
// Critical edges will be split.<br>
static void instrumentOneFunc(<br>
Function &F, Module *M, BranchProbabilityInfo *BPI, BlockFrequencyInfo *BFI,<br>
+ LoopInfo *LI,<br>
std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers) {<br>
FuncPGOInstrumentation<PGOEdge, BBInfo> FuncInfo(F, ComdatMembers, true, BPI,<br>
- BFI);<br>
+ BFI, LI);<br>
unsigned NumCounters = FuncInfo.getNumCounters();<br>
<br>
uint32_t I = 0;<br>
@@ -844,9 +849,10 @@ public:<br>
PGOUseFunc(Function &Func, Module *Modu,<br>
std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers,<br>
BranchProbabilityInfo *BPI = nullptr,<br>
- BlockFrequencyInfo *BFIin = nullptr)<br>
+ BlockFrequencyInfo *BFIin = nullptr,<br>
+ LoopInfo *LI = nullptr)<br>
: F(Func), M(Modu), BFI(BFIin),<br>
- FuncInfo(Func, ComdatMembers, false, BPI, BFIin),<br>
+ FuncInfo(Func, ComdatMembers, false, BPI, BFIin, LI),<br>
FreqAttr(FFA_Normal) {}<br>
<br>
// Read counts for the instrumented BB from profile.<br>
@@ -1379,7 +1385,8 @@ static void collectComdatMembers(<br>
<br>
static bool InstrumentAllFunctions(<br>
Module &M, function_ref<BranchProbabilityInfo *(Function &)> LookupBPI,<br>
- function_ref<BlockFrequencyInfo *(Function &)> LookupBFI) {<br>
+ function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,<br>
+ function_ref<LoopInfo *(Function &)> LookupLI) {<br>
createIRLevelProfileFlagVariable(M);<br>
std::unordered_multimap<Comdat *, GlobalValue *> ComdatMembers;<br>
collectComdatMembers(M, ComdatMembers);<br>
@@ -1389,7 +1396,8 @@ static bool InstrumentAllFunctions(<br>
continue;<br>
auto *BPI = LookupBPI(F);<br>
auto *BFI = LookupBFI(F);<br>
- instrumentOneFunc(F, &M, BPI, BFI, ComdatMembers);<br>
+ auto *LI = LookupLI(F);<br>
+ instrumentOneFunc(F, &M, BPI, BFI, LI, ComdatMembers);<br>
}<br>
return true;<br>
}<br>
@@ -1404,7 +1412,10 @@ bool PGOInstrumentationGenLegacyPass::ru<br>
auto LookupBFI = [this](Function &F) {<br>
return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();<br>
};<br>
- return InstrumentAllFunctions(M, LookupBPI, LookupBFI);<br>
+ auto LookupLI = [this](Function &F) {<br>
+ return &this->getAnalysis<LoopInfoWrapperPass>(F).getLoopInfo();<br>
+ };<br>
+ return InstrumentAllFunctions(M, LookupBPI, LookupBFI, LookupLI);<br>
}<br>
<br>
PreservedAnalyses PGOInstrumentationGen::run(Module &M,<br>
@@ -1418,7 +1429,11 @@ PreservedAnalyses PGOInstrumentationGen:<br>
return &FAM.getResult<BlockFrequencyAnalysis>(F);<br>
};<br>
<br>
- if (!InstrumentAllFunctions(M, LookupBPI, LookupBFI))<br>
+ auto LookupLI = [&FAM](Function &F) {<br>
+ return &FAM.getResult<LoopAnalysis>(F);<br>
+ };<br>
+<br>
+ if (!InstrumentAllFunctions(M, LookupBPI, LookupBFI, LookupLI))<br>
return PreservedAnalyses::all();<br>
<br>
return PreservedAnalyses::none();<br>
@@ -1427,7 +1442,8 @@ PreservedAnalyses PGOInstrumentationGen:<br>
static bool annotateAllFunctions(<br>
Module &M, StringRef ProfileFileName,<br>
function_ref<BranchProbabilityInfo *(Function &)> LookupBPI,<br>
- function_ref<BlockFrequencyInfo *(Function &)> LookupBFI) {<br>
+ function_ref<BlockFrequencyInfo *(Function &)> LookupBFI,<br>
+ function_ref<LoopInfo *(Function &)> LookupLI) {<br>
DEBUG(dbgs() << "Read in profile counters: ");<br>
auto &Ctx = M.getContext();<br>
// Read the counter array from file.<br>
@@ -1463,7 +1479,8 @@ static bool annotateAllFunctions(<br>
continue;<br>
auto *BPI = LookupBPI(F);<br>
auto *BFI = LookupBFI(F);<br>
- PGOUseFunc Func(F, &M, ComdatMembers, BPI, BFI);<br>
+ auto *LI = LookupLI(F);<br>
+ PGOUseFunc Func(F, &M, ComdatMembers, BPI, BFI, LI);<br>
if (!Func.readCounters(PGOReader.get()))<br>
continue;<br>
Func.populateCounters();<br>
@@ -1539,7 +1556,11 @@ PreservedAnalyses PGOInstrumentationUse:<br>
return &FAM.getResult<BlockFrequencyAnalysis>(F);<br>
};<br>
<br>
- if (!annotateAllFunctions(M, ProfileFileName, LookupBPI, LookupBFI))<br>
+ auto LookupLI = [&FAM](Function &F) {<br>
+ return &FAM.getResult<LoopAnalysis>(F);<br>
+ };<br>
+<br>
+ if (!annotateAllFunctions(M, ProfileFileName, LookupBPI, LookupBFI, LookupLI))<br>
return PreservedAnalyses::all();<br>
<br>
return PreservedAnalyses::none();<br>
@@ -1555,8 +1576,11 @@ bool PGOInstrumentationUseLegacyPass::ru<br>
auto LookupBFI = [this](Function &F) {<br>
return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();<br>
};<br>
+ auto LookupLI = [this](Function &F) {<br>
+ return &this->getAnalysis<LoopInfoWrapperPass>(F).getLoopInfo();<br>
+ };<br>
<br>
- return annotateAllFunctions(M, ProfileFileName, LookupBPI, LookupBFI);<br>
+ return annotateAllFunctions(M, ProfileFileName, LookupBPI, LookupBFI, LookupLI);<br>
}<br>
<br>
static std::string getSimpleNodeName(const BasicBlock *Node) {<br>
<br>
Added: llvm/trunk/test/Transforms/PGOProfile/infinite_loop_gen.ll<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PGOProfile/infinite_loop_gen.ll?rev=319794&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PGOProfile/infinite_loop_gen.ll?rev=319794&view=auto</a><br>
==============================================================================<br>
--- llvm/trunk/test/Transforms/PGOProfile/infinite_loop_gen.ll (added)<br>
+++ llvm/trunk/test/Transforms/PGOProfile/infinite_loop_gen.ll Tue Dec 5 09:19:41 2017<br>
@@ -0,0 +1,18 @@<br>
+; RUN: opt < %s -pgo-instr-gen -S -o - | FileCheck %s<br>
+<br>
+define void @foo() {<br>
+entry:<br>
+ br label %while.body<br>
+; CHECK: llvm.instrprof.increment<br>
+<br>
+ while.body: ; preds = %entry, %while.body<br>
+; CHECK: llvm.instrprof.increment<br>
+ call void (...) @bar() #2<br>
+ br label %while.body<br>
+}<br>
+<br>
+declare void @bar(...)<br>
+<br>
+<br>
+attributes #0 = { nounwind }<br>
+<br>
<br>
<br>
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</blockquote></div></div>