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-rw-r--r--lib/Bitcode/Writer/ValueEnumerator.cpp333
1 files changed, 293 insertions, 40 deletions
diff --git a/lib/Bitcode/Writer/ValueEnumerator.cpp b/lib/Bitcode/Writer/ValueEnumerator.cpp
index 15f8034..f065c83 100644
--- a/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -18,31 +18,280 @@
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Module.h"
+#include "llvm/IR/UseListOrder.h"
#include "llvm/IR/ValueSymbolTable.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
using namespace llvm;
+namespace {
+struct OrderMap {
+ DenseMap<const Value *, std::pair<unsigned, bool>> IDs;
+ unsigned LastGlobalConstantID;
+ unsigned LastGlobalValueID;
+
+ OrderMap() : LastGlobalConstantID(0), LastGlobalValueID(0) {}
+
+ bool isGlobalConstant(unsigned ID) const {
+ return ID <= LastGlobalConstantID;
+ }
+ bool isGlobalValue(unsigned ID) const {
+ return ID <= LastGlobalValueID && !isGlobalConstant(ID);
+ }
+
+ unsigned size() const { return IDs.size(); }
+ std::pair<unsigned, bool> &operator[](const Value *V) { return IDs[V]; }
+ std::pair<unsigned, bool> lookup(const Value *V) const {
+ return IDs.lookup(V);
+ }
+ void index(const Value *V) {
+ // Explicitly sequence get-size and insert-value operations to avoid UB.
+ unsigned ID = IDs.size() + 1;
+ IDs[V].first = ID;
+ }
+};
+}
+
+static void orderValue(const Value *V, OrderMap &OM) {
+ if (OM.lookup(V).first)
+ return;
+
+ if (const Constant *C = dyn_cast<Constant>(V))
+ if (C->getNumOperands() && !isa<GlobalValue>(C))
+ for (const Value *Op : C->operands())
+ if (!isa<BasicBlock>(Op) && !isa<GlobalValue>(Op))
+ orderValue(Op, OM);
+
+ // Note: we cannot cache this lookup above, since inserting into the map
+ // changes the map's size, and thus affects the other IDs.
+ OM.index(V);
+}
+
+static OrderMap orderModule(const Module &M) {
+ // This needs to match the order used by ValueEnumerator::ValueEnumerator()
+ // and ValueEnumerator::incorporateFunction().
+ OrderMap OM;
+
+ // In the reader, initializers of GlobalValues are set *after* all the
+ // globals have been read. Rather than awkwardly modeling this behaviour
+ // directly in predictValueUseListOrderImpl(), just assign IDs to
+ // initializers of GlobalValues before GlobalValues themselves to model this
+ // implicitly.
+ for (const GlobalVariable &G : M.globals())
+ if (G.hasInitializer())
+ if (!isa<GlobalValue>(G.getInitializer()))
+ orderValue(G.getInitializer(), OM);
+ for (const GlobalAlias &A : M.aliases())
+ if (!isa<GlobalValue>(A.getAliasee()))
+ orderValue(A.getAliasee(), OM);
+ for (const Function &F : M)
+ if (F.hasPrefixData())
+ if (!isa<GlobalValue>(F.getPrefixData()))
+ orderValue(F.getPrefixData(), OM);
+ OM.LastGlobalConstantID = OM.size();
+
+ // Initializers of GlobalValues are processed in
+ // BitcodeReader::ResolveGlobalAndAliasInits(). Match the order there rather
+ // than ValueEnumerator, and match the code in predictValueUseListOrderImpl()
+ // by giving IDs in reverse order.
+ //
+ // Since GlobalValues never reference each other directly (just through
+ // initializers), their relative IDs only matter for determining order of
+ // uses in their initializers.
+ for (const Function &F : M)
+ orderValue(&F, OM);
+ for (const GlobalAlias &A : M.aliases())
+ orderValue(&A, OM);
+ for (const GlobalVariable &G : M.globals())
+ orderValue(&G, OM);
+ OM.LastGlobalValueID = OM.size();
+
+ for (const Function &F : M) {
+ if (F.isDeclaration())
+ continue;
+ // Here we need to match the union of ValueEnumerator::incorporateFunction()
+ // and WriteFunction(). Basic blocks are implicitly declared before
+ // anything else (by declaring their size).
+ for (const BasicBlock &BB : F)
+ orderValue(&BB, OM);
+ for (const Argument &A : F.args())
+ orderValue(&A, OM);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ for (const Value *Op : I.operands())
+ if ((isa<Constant>(*Op) && !isa<GlobalValue>(*Op)) ||
+ isa<InlineAsm>(*Op))
+ orderValue(Op, OM);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ orderValue(&I, OM);
+ }
+ return OM;
+}
+
+static void predictValueUseListOrderImpl(const Value *V, const Function *F,
+ unsigned ID, const OrderMap &OM,
+ UseListOrderStack &Stack) {
+ // Predict use-list order for this one.
+ typedef std::pair<const Use *, unsigned> Entry;
+ SmallVector<Entry, 64> List;
+ for (const Use &U : V->uses())
+ // Check if this user will be serialized.
+ if (OM.lookup(U.getUser()).first)
+ List.push_back(std::make_pair(&U, List.size()));
+
+ if (List.size() < 2)
+ // We may have lost some users.
+ return;
+
+ bool IsGlobalValue = OM.isGlobalValue(ID);
+ std::sort(List.begin(), List.end(), [&](const Entry &L, const Entry &R) {
+ const Use *LU = L.first;
+ const Use *RU = R.first;
+ if (LU == RU)
+ return false;
+
+ auto LID = OM.lookup(LU->getUser()).first;
+ auto RID = OM.lookup(RU->getUser()).first;
+
+ // Global values are processed in reverse order.
+ //
+ // Moreover, initializers of GlobalValues are set *after* all the globals
+ // have been read (despite having earlier IDs). Rather than awkwardly
+ // modeling this behaviour here, orderModule() has assigned IDs to
+ // initializers of GlobalValues before GlobalValues themselves.
+ if (OM.isGlobalValue(LID) && OM.isGlobalValue(RID))
+ return LID < RID;
+
+ // If ID is 4, then expect: 7 6 5 1 2 3.
+ if (LID < RID) {
+ if (RID <= ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return true;
+ return false;
+ }
+ if (RID < LID) {
+ if (LID <= ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return false;
+ return true;
+ }
+
+ // LID and RID are equal, so we have different operands of the same user.
+ // Assume operands are added in order for all instructions.
+ if (LID <= ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return LU->getOperandNo() < RU->getOperandNo();
+ return LU->getOperandNo() > RU->getOperandNo();
+ });
+
+ if (std::is_sorted(
+ List.begin(), List.end(),
+ [](const Entry &L, const Entry &R) { return L.second < R.second; }))
+ // Order is already correct.
+ return;
+
+ // Store the shuffle.
+ Stack.emplace_back(V, F, List.size());
+ assert(List.size() == Stack.back().Shuffle.size() && "Wrong size");
+ for (size_t I = 0, E = List.size(); I != E; ++I)
+ Stack.back().Shuffle[I] = List[I].second;
+}
+
+static void predictValueUseListOrder(const Value *V, const Function *F,
+ OrderMap &OM, UseListOrderStack &Stack) {
+ auto &IDPair = OM[V];
+ assert(IDPair.first && "Unmapped value");
+ if (IDPair.second)
+ // Already predicted.
+ return;
+
+ // Do the actual prediction.
+ IDPair.second = true;
+ if (!V->use_empty() && std::next(V->use_begin()) != V->use_end())
+ predictValueUseListOrderImpl(V, F, IDPair.first, OM, Stack);
+
+ // Recursive descent into constants.
+ if (const Constant *C = dyn_cast<Constant>(V))
+ if (C->getNumOperands()) // Visit GlobalValues.
+ for (const Value *Op : C->operands())
+ if (isa<Constant>(Op)) // Visit GlobalValues.
+ predictValueUseListOrder(Op, F, OM, Stack);
+}
+
+static UseListOrderStack predictUseListOrder(const Module &M) {
+ OrderMap OM = orderModule(M);
+
+ // Use-list orders need to be serialized after all the users have been added
+ // to a value, or else the shuffles will be incomplete. Store them per
+ // function in a stack.
+ //
+ // Aside from function order, the order of values doesn't matter much here.
+ UseListOrderStack Stack;
+
+ // We want to visit the functions backward now so we can list function-local
+ // constants in the last Function they're used in. Module-level constants
+ // have already been visited above.
+ for (auto I = M.rbegin(), E = M.rend(); I != E; ++I) {
+ const Function &F = *I;
+ if (F.isDeclaration())
+ continue;
+ for (const BasicBlock &BB : F)
+ predictValueUseListOrder(&BB, &F, OM, Stack);
+ for (const Argument &A : F.args())
+ predictValueUseListOrder(&A, &F, OM, Stack);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ for (const Value *Op : I.operands())
+ if (isa<Constant>(*Op) || isa<InlineAsm>(*Op)) // Visit GlobalValues.
+ predictValueUseListOrder(Op, &F, OM, Stack);
+ for (const BasicBlock &BB : F)
+ for (const Instruction &I : BB)
+ predictValueUseListOrder(&I, &F, OM, Stack);
+ }
+
+ // Visit globals last, since the module-level use-list block will be seen
+ // before the function bodies are processed.
+ for (const GlobalVariable &G : M.globals())
+ predictValueUseListOrder(&G, nullptr, OM, Stack);
+ for (const Function &F : M)
+ predictValueUseListOrder(&F, nullptr, OM, Stack);
+ for (const GlobalAlias &A : M.aliases())
+ predictValueUseListOrder(&A, nullptr, OM, Stack);
+ for (const GlobalVariable &G : M.globals())
+ if (G.hasInitializer())
+ predictValueUseListOrder(G.getInitializer(), nullptr, OM, Stack);
+ for (const GlobalAlias &A : M.aliases())
+ predictValueUseListOrder(A.getAliasee(), nullptr, OM, Stack);
+ for (const Function &F : M)
+ if (F.hasPrefixData())
+ predictValueUseListOrder(F.getPrefixData(), nullptr, OM, Stack);
+
+ return Stack;
+}
+
static bool isIntOrIntVectorValue(const std::pair<const Value*, unsigned> &V) {
return V.first->getType()->isIntOrIntVectorTy();
}
-/// ValueEnumerator - Enumerate module-level information.
-ValueEnumerator::ValueEnumerator(const Module *M) {
+ValueEnumerator::ValueEnumerator(const Module &M) {
+ if (shouldPreserveBitcodeUseListOrder())
+ UseListOrders = predictUseListOrder(M);
+
// Enumerate the global variables.
- for (Module::const_global_iterator I = M->global_begin(),
- E = M->global_end(); I != E; ++I)
+ for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
+ I != E; ++I)
EnumerateValue(I);
// Enumerate the functions.
- for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
+ for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
EnumerateValue(I);
EnumerateAttributes(cast<Function>(I)->getAttributes());
}
// Enumerate the aliases.
- for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
+ for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
I != E; ++I)
EnumerateValue(I);
@@ -50,30 +299,30 @@ ValueEnumerator::ValueEnumerator(const Module *M) {
unsigned FirstConstant = Values.size();
// Enumerate the global variable initializers.
- for (Module::const_global_iterator I = M->global_begin(),
- E = M->global_end(); I != E; ++I)
+ for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
+ I != E; ++I)
if (I->hasInitializer())
EnumerateValue(I->getInitializer());
// Enumerate the aliasees.
- for (Module::const_alias_iterator I = M->alias_begin(), E = M->alias_end();
+ for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
I != E; ++I)
EnumerateValue(I->getAliasee());
// Enumerate the prefix data constants.
- for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
+ for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I)
if (I->hasPrefixData())
EnumerateValue(I->getPrefixData());
// Insert constants and metadata that are named at module level into the slot
// pool so that the module symbol table can refer to them...
- EnumerateValueSymbolTable(M->getValueSymbolTable());
+ EnumerateValueSymbolTable(M.getValueSymbolTable());
EnumerateNamedMetadata(M);
- SmallVector<std::pair<unsigned, MDNode*>, 8> MDs;
+ SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
// Enumerate types used by function bodies and argument lists.
- for (const Function &F : *M) {
+ for (const Function &F : M) {
for (const Argument &A : F.args())
EnumerateType(A.getType());
@@ -179,6 +428,11 @@ void ValueEnumerator::print(raw_ostream &OS, const ValueMapType &Map,
void ValueEnumerator::OptimizeConstants(unsigned CstStart, unsigned CstEnd) {
if (CstStart == CstEnd || CstStart+1 == CstEnd) return;
+ if (shouldPreserveBitcodeUseListOrder())
+ // Optimizing constants makes the use-list order difficult to predict.
+ // Disable it for now when trying to preserve the order.
+ return;
+
std::stable_sort(Values.begin() + CstStart, Values.begin() + CstEnd,
[this](const std::pair<const Value *, unsigned> &LHS,
const std::pair<const Value *, unsigned> &RHS) {
@@ -209,11 +463,12 @@ void ValueEnumerator::EnumerateValueSymbolTable(const ValueSymbolTable &VST) {
EnumerateValue(VI->getValue());
}
-/// EnumerateNamedMetadata - Insert all of the values referenced by
-/// named metadata in the specified module.
-void ValueEnumerator::EnumerateNamedMetadata(const Module *M) {
- for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
- E = M->named_metadata_end(); I != E; ++I)
+/// Insert all of the values referenced by named metadata in the specified
+/// module.
+void ValueEnumerator::EnumerateNamedMetadata(const Module &M) {
+ for (Module::const_named_metadata_iterator I = M.named_metadata_begin(),
+ E = M.named_metadata_end();
+ I != E; ++I)
EnumerateNamedMDNode(I);
}
@@ -239,31 +494,31 @@ void ValueEnumerator::EnumerateMDNodeOperands(const MDNode *N) {
void ValueEnumerator::EnumerateMetadata(const Value *MD) {
assert((isa<MDNode>(MD) || isa<MDString>(MD)) && "Invalid metadata kind");
- // Enumerate the type of this value.
- EnumerateType(MD->getType());
-
+ // Skip function-local nodes themselves, but walk their operands.
const MDNode *N = dyn_cast<MDNode>(MD);
-
- // In the module-level pass, skip function-local nodes themselves, but
- // do walk their operands.
if (N && N->isFunctionLocal() && N->getFunction()) {
EnumerateMDNodeOperands(N);
return;
}
- // Check to see if it's already in!
- unsigned &MDValueID = MDValueMap[MD];
- if (MDValueID) {
- // Increment use count.
- MDValues[MDValueID-1].second++;
+ // Insert a dummy ID to block the co-recursive call to
+ // EnumerateMDNodeOperands() from re-visiting MD in a cyclic graph.
+ //
+ // Return early if there's already an ID.
+ if (!MDValueMap.insert(std::make_pair(MD, 0)).second)
return;
- }
- MDValues.push_back(std::make_pair(MD, 1U));
- MDValueID = MDValues.size();
- // Enumerate all non-function-local operands.
+ // Enumerate the type of this value.
+ EnumerateType(MD->getType());
+
+ // Visit operands first to minimize RAUW.
if (N)
EnumerateMDNodeOperands(N);
+
+ // Replace the dummy ID inserted above with the correct one. MDValueMap may
+ // have changed by inserting operands, so we need a fresh lookup here.
+ MDValues.push_back(MD);
+ MDValueMap[MD] = MDValues.size();
}
/// EnumerateFunctionLocalMetadataa - Incorporate function-local metadata
@@ -277,12 +532,10 @@ void ValueEnumerator::EnumerateFunctionLocalMetadata(const MDNode *N) {
// Check to see if it's already in!
unsigned &MDValueID = MDValueMap[N];
- if (MDValueID) {
- // Increment use count.
- MDValues[MDValueID-1].second++;
+ if (MDValueID)
return;
- }
- MDValues.push_back(std::make_pair(N, 1U));
+
+ MDValues.push_back(N);
MDValueID = MDValues.size();
// To incoroporate function-local information visit all function-local
@@ -487,7 +740,7 @@ void ValueEnumerator::incorporateFunction(const Function &F) {
FnLocalMDVector.push_back(MD);
}
- SmallVector<std::pair<unsigned, MDNode*>, 8> MDs;
+ SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
I->getAllMetadataOtherThanDebugLoc(MDs);
for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
MDNode *N = MDs[i].second;
@@ -510,7 +763,7 @@ void ValueEnumerator::purgeFunction() {
for (unsigned i = NumModuleValues, e = Values.size(); i != e; ++i)
ValueMap.erase(Values[i].first);
for (unsigned i = NumModuleMDValues, e = MDValues.size(); i != e; ++i)
- MDValueMap.erase(MDValues[i].first);
+ MDValueMap.erase(MDValues[i]);
for (unsigned i = 0, e = BasicBlocks.size(); i != e; ++i)
ValueMap.erase(BasicBlocks[i]);
generated by cgit v1.1 at 2024-12-22 18:45:15 +0000