4 files changed, 20 insertions, 9 deletions

diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
index a3f43071b44..0c07e1d878f 100644
--- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
+++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
@@ -78,7 +78,7 @@ static CalleeInfo::HotnessType getHotness(uint64_t ProfileCount,
 static void computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
                                    const Function &F, BlockFrequencyInfo *BFI,
                                    ProfileSummaryInfo *PSI,
-                                   SmallPtrSetImpl<GlobalValue *> &LocalsUsed) {
+                                   bool HasLocalsInUsed) {
   // Summary not currently supported for anonymous functions, they should
   // have been named.
   assert(F.hasName());
@@ -90,8 +90,8 @@ static void computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
   DenseMap<GlobalValue::GUID, CalleeInfo> IndirectCallEdges;
   DenseSet<const Value *> RefEdges;
   ICallPromotionAnalysis ICallAnalysis;
-  bool HasLocalsInUsed = !LocalsUsed.empty();
 
+  bool HasInlineAsmMaybeReferencingInternal = false;
   SmallPtrSet<const User *, 8> Visited;
   for (const BasicBlock &BB : F)
     for (const Instruction &I : BB) {
@@ -105,11 +105,12 @@ static void computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
 
       const auto *CI = dyn_cast<CallInst>(&I);
       // Since we don't know exactly which local values are referenced in inline
-      // assembly, conservatively reference all of them from this function, to
-      // ensure we don't export a reference (which would require renaming and
-      // promotion).
+      // assembly, conservatively mark the function as possibly referencing
+      // a local value from inline assembly to ensure we don't export a
+      // reference (which would require renaming and promotion of the
+      // referenced value).
       if (HasLocalsInUsed && CI && CI->isInlineAsm())
-        RefEdges.insert(LocalsUsed.begin(), LocalsUsed.end());
+        HasInlineAsmMaybeReferencingInternal = true;
 
       auto *CalledValue = CS.getCalledValue();
       auto *CalledFunction = CS.getCalledFunction();
@@ -162,6 +163,8 @@ static void computeFunctionSummary(ModuleSummaryIndex &Index, const Module &M,
   FuncSummary->addCallGraphEdges(CallGraphEdges);
   FuncSummary->addCallGraphEdges(IndirectCallEdges);
   FuncSummary->addRefEdges(RefEdges);
+  if (HasInlineAsmMaybeReferencingInternal)
+    FuncSummary->setHasInlineAsmMaybeReferencingInternal();
   Index.addGlobalValueSummary(F.getName(), std::move(FuncSummary));
 }
 
@@ -232,7 +235,7 @@ ModuleSummaryIndex llvm::buildModuleSummaryIndex(
       BFI = BFIPtr.get();
     }
 
-    computeFunctionSummary(Index, M, F, BFI, PSI, LocalsUsed);
+    computeFunctionSummary(Index, M, F, BFI, PSI, !LocalsUsed.empty());
   }
 
   // Compute summaries for all variables defined in module, and save in the
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index bf1f6a56fa1..94a3bcf8554 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -946,7 +946,10 @@ static GlobalValueSummary::GVFlags getDecodedGVSummaryFlags(uint64_t RawFlags,
   RawFlags = RawFlags >> 4;
   bool NoRename = RawFlags & 0x1;
   bool IsNotViableToInline = RawFlags & 0x2;
-  return GlobalValueSummary::GVFlags(Linkage, NoRename, IsNotViableToInline);
+  bool HasInlineAsmMaybeReferencingInternal = RawFlags & 0x4;
+  return GlobalValueSummary::GVFlags(Linkage, NoRename,
+                                     HasInlineAsmMaybeReferencingInternal,
+                                     IsNotViableToInline);
 }
 
 static GlobalValue::VisibilityTypes getDecodedVisibility(unsigned Val) {
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 288c7c6fac2..80db5b2e061 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -992,6 +992,7 @@ static uint64_t getEncodedGVSummaryFlags(GlobalValueSummary::GVFlags Flags) {
 
   RawFlags |= Flags.NoRename; // bool
   RawFlags |= (Flags.IsNotViableToInline << 1);
+  RawFlags |= (Flags.HasInlineAsmMaybeReferencingInternal << 2);
   // Linkage don't need to be remapped at that time for the summary. Any future
   // change to the getEncodedLinkage() function will need to be taken into
   // account here as well.
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index 3bebc609bea..68626c02038 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -153,7 +153,11 @@ static bool eligibleForImport(const ModuleSummaryIndex &Index,
 
   // Check references (and potential calls) in the same module. If the current
   // value references a global that can't be externally referenced it is not
-  // eligible for import.
+  // eligible for import. First check the flag set when we have possible
+  // opaque references (e.g. inline asm calls), then check the call and
+  // reference sets.
+  if (Summary.hasInlineAsmMaybeReferencingInternal())
+    return false;
   bool AllRefsCanBeExternallyReferenced =
       llvm::all_of(Summary.refs(), [&](const ValueInfo &VI) {
         return canBeExternallyReferenced(Index, VI.getGUID());