[ORC] Promote and rename private symbols inside the CompileOnDemand layer,

rather than require them to have been promoted before being passed in.

Dropping this precondition is better for layer composition (CompileOnDemandLayer
was the only one that placed pre-conditions on the modules that could be added).
It also means that the promoted private symbols do not show up in the target
JITDylib's symbol table. Instead, they are confined to the hidden implementation
dylib that contains the actual definitions.

For the 403.gcc testcase this cut down the public symbol table size from ~15,000
symbols to ~4000, substantially reducing symbol dependence tracking costs.

llvm-svn: 344078

4 files changed, 38 insertions, 8 deletions

diff --git a/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp b/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp
index 368969b7a57..ae1c7e84259 100644
--- a/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/CompileOnDemandLayer.cpp
@@ -134,10 +134,7 @@ void CompileOnDemandLayer2::emit(MaterializationResponsibility R, VModuleKey K,
   SymbolAliasMap NonCallables;
   SymbolAliasMap Callables;
   for (auto &GV : M.global_values()) {
-    assert(GV.hasName() && !GV.hasLocalLinkage() &&
-           "GlobalValues must have been promoted before adding to "
-           "CompileOnDemandLayer");
-    if (GV.isDeclaration() || GV.hasAppendingLinkage())
+    if (GV.isDeclaration() || GV.hasLocalLinkage() || GV.hasAppendingLinkage())
       continue;
 
     auto Name = Mangle(GV.getName());
@@ -259,6 +256,25 @@ void CompileOnDemandLayer2::emitPartition(
     return;
   }
 
+  // Ok -- we actually need to partition the symbols. Promote the symbol
+  // linkages/names.
+  // FIXME: We apply this once per partitioning. It's safe, but overkill.
+  {
+    auto PromotedGlobals = PromoteSymbols(*TSM.getModule());
+    if (!PromotedGlobals.empty()) {
+      MangleAndInterner Mangle(ES, TSM.getModule()->getDataLayout());
+      SymbolFlagsMap SymbolFlags;
+      for (auto &GV : PromotedGlobals)
+        SymbolFlags[Mangle(GV->getName())] =
+            JITSymbolFlags::fromGlobalValue(*GV);
+      if (auto Err = R.defineMaterializing(SymbolFlags)) {
+        ES.reportError(std::move(Err));
+        R.failMaterialization();
+        return;
+      }
+    }
+  }
+
   expandPartition(*GVsToExtract);
 
   // Extract the requested partiton (plus any necessary aliases) and
@@ -268,7 +284,6 @@ void CompileOnDemandLayer2::emitPartition(
   };
 
   auto ExtractedTSM = extractSubModule(TSM, ".submodule", ShouldExtract);
-
   R.replace(llvm::make_unique<PartitioningIRMaterializationUnit>(
       ES, std::move(TSM), *this));
 
diff --git a/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp b/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
index 29c3f4e5636..47cb273ee12 100644
--- a/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/ExecutionUtils.cpp
@@ -99,6 +99,12 @@ void CtorDtorRunner2::add(iterator_range<CtorDtorIterator> CtorDtors) {
     assert(CtorDtor.Func && CtorDtor.Func->hasName() &&
            "Ctor/Dtor function must be named to be runnable under the JIT");
 
+    // FIXME: Maybe use a symbol promoter here instead.
+    if (CtorDtor.Func->hasLocalLinkage()) {
+      CtorDtor.Func->setLinkage(GlobalValue::ExternalLinkage);
+      CtorDtor.Func->setVisibility(GlobalValue::HiddenVisibility);
+    }
+
     if (CtorDtor.Data && cast<GlobalValue>(CtorDtor.Data)->isDeclaration()) {
       dbgs() << "  Skipping because why now?\n";
       continue;
diff --git a/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp b/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
index 0acc5db76f4..d7fd57b6e53 100644
--- a/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
@@ -248,8 +248,11 @@ void makeStub(Function &F, Value &ImplPointer) {
     Builder.CreateRet(Call);
 }
 
-void SymbolLinkagePromoter::operator()(Module &M) {
+std::vector<GlobalValue *> SymbolLinkagePromoter::operator()(Module &M) {
+  std::vector<GlobalValue *> PromotedGlobals;
+
   for (auto &GV : M.global_values()) {
+    bool Promoted = true;
 
     // Rename if necessary.
     if (!GV.hasName())
@@ -258,13 +261,21 @@ void SymbolLinkagePromoter::operator()(Module &M) {
       GV.setName("__" + GV.getName().substr(1) + "." + Twine(NextId++));
     else if (GV.hasLocalLinkage())
       GV.setName("__orc_lcl." + GV.getName() + "." + Twine(NextId++));
+    else
+      Promoted = false;
 
     if (GV.hasLocalLinkage()) {
       GV.setLinkage(GlobalValue::ExternalLinkage);
       GV.setVisibility(GlobalValue::HiddenVisibility);
+      Promoted = true;
     }
     GV.setUnnamedAddr(GlobalValue::UnnamedAddr::None);
+
+    if (Promoted)
+      PromotedGlobals.push_back(&GV);
   }
+
+  return PromotedGlobals;
 }
 
 Function* cloneFunctionDecl(Module &Dst, const Function &F,
diff --git a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
index 89a302ca02f..47baa45a8aa 100644
--- a/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/LLJIT.cpp
@@ -185,8 +185,6 @@ Error LLLazyJIT::addLazyIRModule(JITDylib &JD, ThreadSafeModule TSM) {
   if (auto Err = applyDataLayout(*TSM.getModule()))
     return Err;
 
-  PromoteSymbols(*TSM.getModule());
-
   recordCtorDtors(*TSM.getModule());
 
   auto K = ES->allocateVModule();