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

1 files changed, 23 insertions, 2 deletions

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);