1 files changed, 56 insertions, 6 deletions

diff --git a/llvm/lib/Transforms/Utils/PredicateInfo.cpp b/llvm/lib/Transforms/Utils/PredicateInfo.cpp
index 38cada8cb06..2923977b791 100644
--- a/llvm/lib/Transforms/Utils/PredicateInfo.cpp
+++ b/llvm/lib/Transforms/Utils/PredicateInfo.cpp
@@ -17,6 +17,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/Analysis/AssumptionCache.h"
 #include "llvm/Analysis/CFG.h"
 #include "llvm/IR/AssemblyAnnotationWriter.h"
@@ -24,6 +25,7 @@
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InstIterator.h"
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Metadata.h"
@@ -479,6 +481,19 @@ void PredicateInfo::buildPredicateInfo() {
   renameUses(OpsToRename);
 }
 
+// Create a ssa_copy declaration with custom mangling, because
+// Intrinsic::getDeclaration does not handle overloaded unnamed types properly:
+// all unnamed types get mangled to the same string. We use the pointer
+// to the type as name here, as it guarantees unique names for different
+// types and we remove the declarations when destroying PredicateInfo.
+// It is a workaround for PR38117, because solving it in a fully general way is
+// tricky (FIXME).
+static Function *getCopyDeclaration(Module *M, Type *Ty) {
+  std::string Name = "llvm.ssa.copy." + utostr((uintptr_t) Ty);
+  return cast<Function>(M->getOrInsertFunction(
+      Name, getType(M->getContext(), Intrinsic::ssa_copy, Ty)));
+}
+
 // Given the renaming stack, make all the operands currently on the stack real
 // by inserting them into the IR.  Return the last operation's value.
 Value *PredicateInfo::materializeStack(unsigned int &Counter,
@@ -507,8 +522,9 @@ Value *PredicateInfo::materializeStack(unsigned int &Counter,
     // order in the case of multiple predicateinfo in the same block.
     if (isa<PredicateWithEdge>(ValInfo)) {
       IRBuilder<> B(getBranchTerminator(ValInfo));
-      Function *IF = Intrinsic::getDeclaration(
-          F.getParent(), Intrinsic::ssa_copy, Op->getType());
+      Function *IF = getCopyDeclaration(F.getParent(), Op->getType());
+      if (IF->user_begin() == IF->user_end())
+        CreatedDeclarations.insert(IF);
       CallInst *PIC =
           B.CreateCall(IF, Op, Op->getName() + "." + Twine(Counter++));
       PredicateMap.insert({PIC, ValInfo});
@@ -518,8 +534,9 @@ Value *PredicateInfo::materializeStack(unsigned int &Counter,
       assert(PAssume &&
              "Should not have gotten here without it being an assume");
       IRBuilder<> B(PAssume->AssumeInst);
-      Function *IF = Intrinsic::getDeclaration(
-          F.getParent(), Intrinsic::ssa_copy, Op->getType());
+      Function *IF = getCopyDeclaration(F.getParent(), Op->getType());
+      if (IF->user_begin() == IF->user_end())
+        CreatedDeclarations.insert(IF);
       CallInst *PIC = B.CreateCall(IF, Op);
       PredicateMap.insert({PIC, ValInfo});
       Result.Def = PIC;
@@ -704,7 +721,22 @@ PredicateInfo::PredicateInfo(Function &F, DominatorTree &DT,
   buildPredicateInfo();
 }
 
-PredicateInfo::~PredicateInfo() {}
+// Remove all declarations we created . The PredicateInfo consumers are
+// responsible for remove the ssa_copy calls created.
+PredicateInfo::~PredicateInfo() {
+  // Collect function pointers in set first, as SmallSet uses a SmallVector
+  // internally and we have to remove the asserting value handles first.
+  SmallPtrSet<Function *, 20> FunctionPtrs;
+  for (auto &F : CreatedDeclarations)
+    FunctionPtrs.insert(&*F);
+  CreatedDeclarations.clear();
+
+  for (Function *F : FunctionPtrs) {
+    assert(F->user_begin() == F->user_end() &&
+           "PredicateInfo consumer did not remove all SSA copies.");
+    F->eraseFromParent();
+  }
+}
 
 void PredicateInfo::verifyPredicateInfo() const {}
 
@@ -722,6 +754,20 @@ void PredicateInfoPrinterLegacyPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<AssumptionCacheTracker>();
 }
 
+// Replace ssa_copy calls created by PredicateInfo with their operand.
+static void replaceCreatedSSACopys(PredicateInfo &PredInfo, Function &F) {
+  for (auto I = inst_begin(F), E = inst_end(F); I != E;) {
+    Instruction *Inst = &*I++;
+    const auto *PI = PredInfo.getPredicateInfoFor(Inst);
+    auto *II = dyn_cast<IntrinsicInst>(Inst);
+    if (!PI || !II || II->getIntrinsicID() != Intrinsic::ssa_copy)
+      continue;
+
+    Inst->replaceAllUsesWith(II->getOperand(0));
+    Inst->eraseFromParent();
+  }
+}
+
 bool PredicateInfoPrinterLegacyPass::runOnFunction(Function &F) {
   auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
   auto &AC = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
@@ -729,6 +775,8 @@ bool PredicateInfoPrinterLegacyPass::runOnFunction(Function &F) {
   PredInfo->print(dbgs());
   if (VerifyPredicateInfo)
     PredInfo->verifyPredicateInfo();
+
+  replaceCreatedSSACopys(*PredInfo, F);
   return false;
 }
 
@@ -737,8 +785,10 @@ PreservedAnalyses PredicateInfoPrinterPass::run(Function &F,
   auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
   auto &AC = AM.getResult<AssumptionAnalysis>(F);
   OS << "PredicateInfo for function: " << F.getName() << "\n";
-  make_unique<PredicateInfo>(F, DT, AC)->print(OS);
+  auto PredInfo = make_unique<PredicateInfo>(F, DT, AC);
+  PredInfo->print(OS);
 
+  replaceCreatedSSACopys(*PredInfo, F);
   return PreservedAnalyses::all();
 }