[llvm] r288528 - [PGO] Fix PGO use ICE when there are unreachable BBs
Rong Xu via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 2 11:10:30 PST 2016
Author: xur
Date: Fri Dec 2 13:10:29 2016
New Revision: 288528
URL: http://llvm.org/viewvc/llvm-project?rev=288528&view=rev
Log:
[PGO] Fix PGO use ICE when there are unreachable BBs
For -O0 there might be unreachable BBs, which breaks the assumption that all the
BBs have an auxiliary data structure. In this patch, we add another interface
called findBBInfo() so that a nullptr can be returned for the unreachable BBs
(and the callers can ignore those BBs).
This fixes the bug reported
https://llvm.org/bugs/show_bug.cgi?id=31209
Differential Revision: https://reviews.llvm.org/D27280
Added:
llvm/trunk/test/Transforms/PGOProfile/Inputs/unreachable_bb.proftext
llvm/trunk/test/Transforms/PGOProfile/unreachable_bb.ll
Modified:
llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h
llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
Modified: llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h?rev=288528&r1=288527&r2=288528&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/CFGMST.h Fri Dec 2 13:10:29 2016
@@ -78,6 +78,14 @@ public:
return *It->second.get();
}
+ // Give BB, return the auxiliary information if it's available.
+ BBInfo *findBBInfo(const BasicBlock *BB) const {
+ auto It = BBInfos.find(BB);
+ if (It == BBInfos.end())
+ return nullptr;
+ return It->second.get();
+ }
+
// Traverse the CFG using a stack. Find all the edges and assign the weight.
// Edges with large weight will be put into MST first so they are less likely
// to be instrumented.
Modified: llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp?rev=288528&r1=288527&r2=288528&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/PGOInstrumentation.cpp Fri Dec 2 13:10:29 2016
@@ -327,6 +327,9 @@ public:
// Return the auxiliary BB information.
BBInfo &getBBInfo(const BasicBlock *BB) const { return MST.getBBInfo(BB); }
+ // Return the auxiliary BB information if available.
+ BBInfo *findBBInfo(const BasicBlock *BB) const { return MST.findBBInfo(BB); }
+
// Dump edges and BB information.
void dumpInfo(std::string Str = "") const {
MST.dumpEdges(dbgs(), Twine("Dump Function ") + FuncName + " Hash: " +
@@ -386,7 +389,10 @@ void FuncPGOInstrumentation<Edge, BBInfo
const TerminatorInst *TI = BB.getTerminator();
for (unsigned I = 0, E = TI->getNumSuccessors(); I != E; ++I) {
BasicBlock *Succ = TI->getSuccessor(I);
- uint32_t Index = getBBInfo(Succ).Index;
+ auto BI = findBBInfo(Succ);
+ if (BI == nullptr)
+ continue;
+ uint32_t Index = BI->Index;
for (int J = 0; J < 4; J++)
Indexes.push_back((char)(Index >> (J * 8)));
}
@@ -672,6 +678,11 @@ public:
return FuncInfo.getBBInfo(BB);
}
+ // Return the auxiliary BB information if available.
+ UseBBInfo *findBBInfo(const BasicBlock *BB) const {
+ return FuncInfo.findBBInfo(BB);
+ }
+
private:
Function &F;
Module *M;
@@ -857,27 +868,29 @@ void PGOUseFunc::populateCounters() {
// For efficient traversal, it's better to start from the end as most
// of the instrumented edges are at the end.
for (auto &BB : reverse(F)) {
- UseBBInfo &Count = getBBInfo(&BB);
- if (!Count.CountValid) {
- if (Count.UnknownCountOutEdge == 0) {
- Count.CountValue = sumEdgeCount(Count.OutEdges);
- Count.CountValid = true;
+ UseBBInfo *Count = findBBInfo(&BB);
+ if (Count == nullptr)
+ continue;
+ if (!Count->CountValid) {
+ if (Count->UnknownCountOutEdge == 0) {
+ Count->CountValue = sumEdgeCount(Count->OutEdges);
+ Count->CountValid = true;
Changes = true;
- } else if (Count.UnknownCountInEdge == 0) {
- Count.CountValue = sumEdgeCount(Count.InEdges);
- Count.CountValid = true;
+ } else if (Count->UnknownCountInEdge == 0) {
+ Count->CountValue = sumEdgeCount(Count->InEdges);
+ Count->CountValid = true;
Changes = true;
}
}
- if (Count.CountValid) {
- if (Count.UnknownCountOutEdge == 1) {
- uint64_t Total = Count.CountValue - sumEdgeCount(Count.OutEdges);
- setEdgeCount(Count.OutEdges, Total);
+ if (Count->CountValid) {
+ if (Count->UnknownCountOutEdge == 1) {
+ uint64_t Total = Count->CountValue - sumEdgeCount(Count->OutEdges);
+ setEdgeCount(Count->OutEdges, Total);
Changes = true;
}
- if (Count.UnknownCountInEdge == 1) {
- uint64_t Total = Count.CountValue - sumEdgeCount(Count.InEdges);
- setEdgeCount(Count.InEdges, Total);
+ if (Count->UnknownCountInEdge == 1) {
+ uint64_t Total = Count->CountValue - sumEdgeCount(Count->InEdges);
+ setEdgeCount(Count->InEdges, Total);
Changes = true;
}
}
@@ -887,14 +900,22 @@ void PGOUseFunc::populateCounters() {
DEBUG(dbgs() << "Populate counts in " << NumPasses << " passes.\n");
#ifndef NDEBUG
// Assert every BB has a valid counter.
- for (auto &BB : F)
- assert(getBBInfo(&BB).CountValid && "BB count is not valid");
+ for (auto &BB : F) {
+ auto BI = findBBInfo(&BB);
+ if (BI == nullptr)
+ continue;
+ assert(BI->CountValid && "BB count is not valid");
+ }
#endif
uint64_t FuncEntryCount = getBBInfo(&*F.begin()).CountValue;
F.setEntryCount(FuncEntryCount);
uint64_t FuncMaxCount = FuncEntryCount;
- for (auto &BB : F)
- FuncMaxCount = std::max(FuncMaxCount, getBBInfo(&BB).CountValue);
+ for (auto &BB : F) {
+ auto BI = findBBInfo(&BB);
+ if (BI == nullptr)
+ continue;
+ FuncMaxCount = std::max(FuncMaxCount, BI->CountValue);
+ }
markFunctionAttributes(FuncEntryCount, FuncMaxCount);
// Now annotate select instructions
@@ -974,7 +995,10 @@ void SelectInstVisitor::annotateOneSelec
uint64_t SCounts[2];
SCounts[0] = CountFromProfile[*CurCtrIdx]; // True count
++(*CurCtrIdx);
- uint64_t TotalCount = UseFunc->getBBInfo(SI.getParent()).CountValue;
+ uint64_t TotalCount = 0;
+ auto BI = UseFunc->findBBInfo(SI.getParent());
+ if (BI != nullptr)
+ TotalCount = BI->CountValue;
// False Count
SCounts[1] = (TotalCount > SCounts[0] ? TotalCount - SCounts[0] : 0);
uint64_t MaxCount = std::max(SCounts[0], SCounts[1]);
Added: llvm/trunk/test/Transforms/PGOProfile/Inputs/unreachable_bb.proftext
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PGOProfile/Inputs/unreachable_bb.proftext?rev=288528&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/PGOProfile/Inputs/unreachable_bb.proftext (added)
+++ llvm/trunk/test/Transforms/PGOProfile/Inputs/unreachable_bb.proftext Fri Dec 2 13:10:29 2016
@@ -0,0 +1,9 @@
+# IR level Instrumentation Flag
+:ir
+foo
+# Func Hash:
+12884901887
+# Num Counters:
+1
+# Counter Values:
+0
Added: llvm/trunk/test/Transforms/PGOProfile/unreachable_bb.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/PGOProfile/unreachable_bb.ll?rev=288528&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/PGOProfile/unreachable_bb.ll (added)
+++ llvm/trunk/test/Transforms/PGOProfile/unreachable_bb.ll Fri Dec 2 13:10:29 2016
@@ -0,0 +1,23 @@
+; RUN: llvm-profdata merge %S/Inputs/unreachable_bb.proftext -o %t.profdata
+; RUN: opt < %s -pgo-instr-use -pgo-test-profile-file=%t.profdata -S | FileCheck %s --check-prefix=USE
+; RUN: opt < %s -passes=pgo-instr-use -pgo-test-profile-file=%t.profdata -S | FileCheck %s --check-prefix=USE
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @foo() {
+entry:
+ call void @bar()
+ unreachable
+return:
+ ret void
+}
+
+declare void @bar()
+
+;USE: !0 = !{i32 1, !"ProfileSummary", !1}
+;USE: !1 = !{!2, !3, !4, !5, !6, !7, !8, !9}
+;USE: !2 = !{!"ProfileFormat", !"InstrProf"}
+;USE: !3 = !{!"TotalCount", i64 0}
+
+
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