Merge pull request #30738 from apple/revert-30689-curry-thunk-peephole

Revert "SILOptimizer: Peephole to eliminate closures which just apply a witness_method"

Author: shahmishal

lib/SILOptimizer/SILCombiner/SILCombinerApplyVisitors.cpp

@@ -78,104 +78,6 @@ static bool foldInverseReabstractionThunks(PartialApplyInst *PAI,
   return true;
 }
 
-ApplyInst *getSingleApplyInBlock(SILBasicBlock &BB) {
-  ApplyInst *Result = nullptr;
-
-  for (auto &I : BB) {
-    if (isa<DebugValueAddrInst>(I) ||
-        isa<DebugValueInst>(I))
-      continue;
-
-    // FIXME: Should also support ClassMethodInst
-    if (isa<WitnessMethodInst>(I) ||
-        isa<ReturnInst>(I))
-      continue;
-
-    if (auto *TI = dyn_cast<TupleInst>(&I))
-      if (TI->getElements().empty())
-        continue;
-
-    if (auto *AI = dyn_cast<ApplyInst>(&I)) {
-      if (Result == nullptr) {
-        Result = AI;
-        continue;
-      }
-    }
-
-    return nullptr;
-  }
-
-  return Result;
-}
-
-static bool foldPartialApplyOfTrivialClosure(PartialApplyInst *PAI,
-                                             SILCombiner *Combiner) {
-  auto *FRI = dyn_cast<FunctionRefInst>(PAI->getCallee());
-  if (FRI == nullptr)
-    return false;
-
-  auto *F = FRI->getReferencedFunctionOrNull();
-  if (F == nullptr)
-    return false;
-
-  // The referenced function must consist of a single basic block.
-  if (F->getBlocks().size() != 1)
-    return false;
-
-  // The referenced function must not throw.
-  if (F->getLoweredFunctionType()->getOptionalErrorResult())
-    return false;
-
-  // The only non-trivial instructions in the function must be an apply
-  // of a witness_method callee.
-  auto &BB = *F->getBlocks().begin();
-  auto *AI = getSingleApplyInBlock(BB);
-  if (AI == nullptr)
-    return false;
-
-  // The apply instruction must have the same number of arguments as the
-  // function that contains it, and they must be passed in order.
-  auto InnerArgs = AI->getArguments();
-  if (InnerArgs.size() != BB.args_size())
-    return false;
-
-  auto ArgsIter = BB.args_begin();
-  for (auto Arg : InnerArgs) {
-    if (Arg != *(ArgsIter++))
-      return false;
-  }
-
-  SILBuilderWithScope B(PAI);
-
-  // FIXME: Should also support ClassMethodInst
-  auto *WMI = cast<WitnessMethodInst>(AI->getCallee());
-  auto InnerSubs = PAI->getSubstitutionMap();
-  auto Subs = AI->getSubstitutionMap().subst(InnerSubs);
-  auto *NewCallee = B.createWitnessMethod(
-      WMI->getLoc(),
-      WMI->getLookupType().subst(InnerSubs)->getCanonicalType(),
-      WMI->getConformance().subst(WMI->getLookupType(), InnerSubs),
-      WMI->getMember(),
-      WMI->getType().subst(F->getModule().Types, InnerSubs));
-
-  SmallVector<SILValue, 8> NewArgs;
-  auto Args = PAI->getArguments();
-  NewArgs.append(Args.begin(), Args.end());
-
-  auto *NewPAI = B.createPartialApply(
-      PAI->getLoc(),
-      NewCallee,
-      Subs,
-      NewArgs,
-      PAI->getType().getAs<SILFunctionType>()->getCalleeConvention(),
-      PAI->isOnStack());
-
-  assert(PAI->getType() == NewPAI->getType());
-  PAI->replaceAllUsesWith(NewPAI);
-  Combiner->eraseInstFromFunction(*PAI);
-  return true;
-}
-
 SILInstruction *SILCombiner::visitPartialApplyInst(PartialApplyInst *PAI) {
   if (PAI->getFunction()->hasOwnership())
     return nullptr;
@@ -207,11 +109,6 @@ SILInstruction *SILCombiner::visitPartialApplyInst(PartialApplyInst *PAI) {
   if (foldInverseReabstractionThunks(PAI, this))
     return nullptr;
 
-  // partial_apply %function_ref => partial_apply %witness_method if
-  // the body of the function_ref is just an apply %witness_method
-  if (foldPartialApplyOfTrivialClosure(PAI, this))
-    return nullptr;
-
   bool argsAreKeptAlive = tryOptimizeApplyOfPartialApply(
       PAI, Builder.getBuilderContext(), getInstModCallbacks());
   if (argsAreKeptAlive)

lib/SILOptimizer/Utils/Devirtualize.cpp

@@ -589,8 +589,7 @@ replacePartialApplyInst(SILBuilder &builder, SILLocation loc,
   auto convention =
       oldPAI->getType().getAs<SILFunctionType>()->getCalleeConvention();
   auto *newPAI =
-      builder.createPartialApply(loc, newFn, newSubs, newArgs, convention,
-                                 oldPAI->isOnStack());
+      builder.createPartialApply(loc, newFn, newSubs, newArgs, convention);
 
   // Check if any casting is required for the partially-applied function.
   SILValue resultValue = castValueToABICompatibleType(