Remangle intrinsics names when types are renamed

This is a resubmittion of previously reverted rL273568.

This is a fix for the problem mentioned in "LTO and intrinsics mangling" llvm-dev mail thread:
http://lists.llvm.org/pipermail/llvm-dev/2016-April/098387.html

Reviewers: mehdi_amini, reames

Differential Revision: http://reviews.llvm.org/D19373

llvm-svn: 273686

4 files changed, 79 insertions, 2 deletions

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 691625209e4..bf4934c4f73 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -18,12 +18,14 @@
 #include "llvm/AsmParser/SlotMapping.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/CallingConv.h"
+#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Instructions.h"
+#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/Operator.h"
@@ -210,6 +212,17 @@ bool LLParser::ValidateEndOfModule() {
   for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; )
     UpgradeCallsToIntrinsic(&*FI++); // must be post-increment, as we remove
 
+  // Some types could be renamed during loading if several modules are
+  // loaded in the same LLVMContext (LTO scenario). In this case we should
+  // remangle intrinsics names as well.
+  for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ) {
+    Function *F = &*FI++;
+    if (auto Remangled = Intrinsic::remangleIntrinsicFunction(F)) {
+      F->replaceAllUsesWith(Remangled.getValue());
+      F->eraseFromParent();
+    }
+  }
+
   UpgradeDebugInfo(*M);
 
   UpgradeModuleFlags(*M);
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index a9c509809cb..cdb6a1f30bf 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -15,6 +15,7 @@
 #include "llvm/Bitcode/LLVMBitCodes.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/AutoUpgrade.h"
+#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DebugInfoMetadata.h"
@@ -230,8 +231,10 @@ class BitcodeReader : public GVMaterializer {
 
   // When intrinsic functions are encountered which require upgrading they are
   // stored here with their replacement function.
-  typedef DenseMap<Function*, Function*> UpgradedIntrinsicMap;
-  UpgradedIntrinsicMap UpgradedIntrinsics;
+  typedef DenseMap<Function*, Function*> UpdatedIntrinsicMap;
+  UpdatedIntrinsicMap UpgradedIntrinsics;
+  // Intrinsics which were remangled because of types rename
+  UpdatedIntrinsicMap RemangledIntrinsics;
 
   // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
   DenseMap<unsigned, unsigned> MDKindMap;
@@ -3425,6 +3428,11 @@ std::error_code BitcodeReader::globalCleanup() {
     Function *NewFn;
     if (UpgradeIntrinsicFunction(&F, NewFn))
       UpgradedIntrinsics[&F] = NewFn;
+    else if (auto Remangled = Intrinsic::remangleIntrinsicFunction(&F))
+      // Some types could be renamed during loading if several modules are
+      // loaded in the same LLVMContext (LTO scenario). In this case we should
+      // remangle intrinsics names as well.
+      RemangledIntrinsics[&F] = Remangled.getValue();
   }
 
   // Look for global variables which need to be renamed.
@@ -5601,6 +5609,13 @@ std::error_code BitcodeReader::materialize(GlobalValue *GV) {
     }
   }
 
+  // Update calls to the remangled intrinsics
+  for (auto &I : RemangledIntrinsics)
+    for (auto UI = I.first->materialized_user_begin(), UE = I.first->user_end();
+         UI != UE;)
+      // Don't expect any other users than call sites
+      CallSite(*UI++).setCalledFunction(I.second);
+
   // Finish fn->subprogram upgrade for materialized functions.
   if (DISubprogram *SP = FunctionsWithSPs.lookup(F))
     F->setSubprogram(SP);
@@ -5654,6 +5669,12 @@ std::error_code BitcodeReader::materializeModule() {
     I.first->eraseFromParent();
   }
   UpgradedIntrinsics.clear();
+  // Do the same for remangled intrinsics
+  for (auto &I : RemangledIntrinsics) {
+    I.first->replaceAllUsesWith(I.second);
+    I.first->eraseFromParent();
+  }
+  RemangledIntrinsics.clear();
 
   UpgradeDebugInfo(*TheModule);
 
diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index 29ed68a2c5e..0da9b98258c 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -1080,6 +1080,40 @@ Intrinsic::matchIntrinsicVarArg(bool isVarArg,
   return true;
 }
 
+Optional<Function*> Intrinsic::remangleIntrinsicFunction(Function *F) {
+  Intrinsic::ID ID = F->getIntrinsicID();
+  if (!ID)
+    return None;
+
+  FunctionType *FTy = F->getFunctionType();
+  // Accumulate an array of overloaded types for the given intrinsic
+  SmallVector<Type *, 4> ArgTys;
+  {
+    SmallVector<Intrinsic::IITDescriptor, 8> Table;
+    getIntrinsicInfoTableEntries(ID, Table);
+    ArrayRef<Intrinsic::IITDescriptor> TableRef = Table;
+
+    // If we encounter any problems matching the signature with the descriptor
+    // just give up remangling. It's up to verifier to report the discrepancy.
+    if (Intrinsic::matchIntrinsicType(FTy->getReturnType(), TableRef, ArgTys))
+      return None;
+    for (auto Ty : FTy->params())
+      if (Intrinsic::matchIntrinsicType(Ty, TableRef, ArgTys))
+        return None;
+    if (Intrinsic::matchIntrinsicVarArg(FTy->isVarArg(), TableRef))
+      return None;
+  }
+
+  StringRef Name = F->getName();
+  if (Name == Intrinsic::getName(ID, ArgTys))
+    return None;
+
+  auto NewDecl = Intrinsic::getDeclaration(F->getParent(), ID, ArgTys);
+  NewDecl->setCallingConv(F->getCallingConv());
+  assert(NewDecl->getFunctionType() == FTy && "Shouldn't change the signature");
+  return NewDecl;
+}
+
 /// hasAddressTaken - returns true if there are any uses of this function
 /// other than direct calls or invokes to it.
 bool Function::hasAddressTaken(const User* *PutOffender) const {
diff --git a/llvm/lib/Linker/IRMover.cpp b/llvm/lib/Linker/IRMover.cpp
index 7d09b7be868..c82fc8b3dff 100644
--- a/llvm/lib/Linker/IRMover.cpp
+++ b/llvm/lib/Linker/IRMover.cpp
@@ -16,6 +16,7 @@
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
 #include "llvm/IR/GVMaterializer.h"
+#include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/TypeFinder.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Transforms/Utils/Cloning.h"
@@ -901,6 +902,14 @@ Expected<Constant *> IRLinker::linkGlobalValueProto(GlobalValue *SGV,
     if (ShouldLink || !ForAlias)
       forceRenaming(NewGV, SGV->getName());
   }
+
+  // Overloaded intrinsics have overloaded types names as part of their
+  // names. If we renamed overloaded types we should rename the intrinsic
+  // as well.
+  if (Function *F = dyn_cast<Function>(NewGV))
+    if (auto Remangled = Intrinsic::remangleIntrinsicFunction(F))
+      NewGV = Remangled.getValue();
+
   if (ShouldLink || ForAlias) {
     if (const Comdat *SC = SGV->getComdat()) {
       if (auto *GO = dyn_cast<GlobalObject>(NewGV)) {