Revert of D49126 [PredicateInfo] Use custom mangling to support ssa_copy with unnamed types.

Now that intrinsic name mangling can cope with unnamed types, the custom name mangling in PredicateInfo (introduced by D49126) can be removed.
(See D91250, D48541)

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D91661

1 files changed, 4 insertions, 56 deletions

diff --git a/llvm/lib/Transforms/Utils/PredicateInfo.cpp b/llvm/lib/Transforms/Utils/PredicateInfo.cpp
index 4c262f6..9128076 100644
--- a/llvm/lib/Transforms/Utils/PredicateInfo.cpp
+++ b/llvm/lib/Transforms/Utils/PredicateInfo.cpp
@@ -16,7 +16,6 @@
 #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"
@@ -24,7 +23,6 @@
 #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"
@@ -539,21 +537,6 @@ void PredicateInfoBuilder::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))
-          .getCallee());
-}
-
 // 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 *PredicateInfoBuilder::materializeStack(unsigned int &Counter,
@@ -585,9 +568,8 @@ Value *PredicateInfoBuilder::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 = getCopyDeclaration(F.getParent(), Op->getType());
-      if (IF->users().empty())
-        PI.CreatedDeclarations.insert(IF);
+      Function *IF = Intrinsic::getDeclaration(
+          F.getParent(), Intrinsic::ssa_copy, Op->getType());
       CallInst *PIC =
           B.CreateCall(IF, Op, Op->getName() + "." + Twine(Counter++));
       PI.PredicateMap.insert({PIC, ValInfo});
@@ -599,9 +581,8 @@ Value *PredicateInfoBuilder::materializeStack(unsigned int &Counter,
       // Insert the predicate directly after the assume. While it also holds
       // directly before it, assume(i1 true) is not a useful fact.
       IRBuilder<> B(PAssume->AssumeInst->getNextNode());
-      Function *IF = getCopyDeclaration(F.getParent(), Op->getType());
-      if (IF->users().empty())
-        PI.CreatedDeclarations.insert(IF);
+      Function *IF = Intrinsic::getDeclaration(
+          F.getParent(), Intrinsic::ssa_copy, Op->getType());
       CallInst *PIC = B.CreateCall(IF, Op);
       PI.PredicateMap.insert({PIC, ValInfo});
       Result.Def = PIC;
@@ -780,23 +761,6 @@ PredicateInfo::PredicateInfo(Function &F, DominatorTree &DT,
   Builder.buildPredicateInfo();
 }
 
-// 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();
-  }
-}
-
 Optional<PredicateConstraint> PredicateBase::getConstraint() const {
   switch (Type) {
   case PT_Assume:
@@ -863,19 +827,6 @@ 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 (Instruction &Inst : llvm::make_early_inc_range(instructions(F))) {
-    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);
@@ -883,8 +834,6 @@ bool PredicateInfoPrinterLegacyPass::runOnFunction(Function &F) {
   PredInfo->print(dbgs());
   if (VerifyPredicateInfo)
     PredInfo->verifyPredicateInfo();
-
-  replaceCreatedSSACopys(*PredInfo, F);
   return false;
 }
 
@@ -896,7 +845,6 @@ PreservedAnalyses PredicateInfoPrinterPass::run(Function &F,
   auto PredInfo = std::make_unique<PredicateInfo>(F, DT, AC);
   PredInfo->print(OS);
 
-  replaceCreatedSSACopys(*PredInfo, F);
   return PreservedAnalyses::all();
 }