SIL Optimizer: remove legacy C++ passes

They were used as a backup during the transition to Swift passes. Now they are not needed anymore.

Author: eeckstein

include/swift/SILOptimizer/PassManager/Passes.def

@@ -65,16 +65,6 @@
 #define SWIFT_FUNCTION_PASS(Id, Tag, Description) PASS(Id, Tag, Description)
 #endif
 
-/// SWIFT_FUNCTION_PASS_WITH_LEGACY(Id, Tag, Description)
-///   Like SWIFT_FUNCTION_PASS, but a C++ legacy pass is used if the Swift pass
-///   is not registered.
-///   The C++ legacy creation function must be named 'createLegacy<Id>'
-///
-#ifndef SWIFT_FUNCTION_PASS_WITH_LEGACY
-#define SWIFT_FUNCTION_PASS_WITH_LEGACY(Id, Tag, Description) \
-        SWIFT_FUNCTION_PASS(Id, Tag, Description)
-#endif
-
 /// SWIFT_INSTRUCTION_PASS(Inst, Tag)
 ///   Similar to SWIFT_FUNCTION_PASS, but defines an instruction pass which is
 ///   implemented in swift and is run by the SILCombiner.
@@ -88,17 +78,6 @@
 #define SWIFT_INSTRUCTION_PASS(Inst, Tag)
 #endif
 
-/// SWIFT_INSTRUCTION_PASS_WITH_LEGACY(Inst, Tag)
-///   Like SWIFT_INSTRUCTION_PASS, but the a C++ legacy SILCombine visit
-///   function is used if the swift pass is not registered.
-///   The C++ legacy visit function must be named
-///   'SILCombiner::legacyVisit<Inst>'.
-///
-#ifndef SWIFT_INSTRUCTION_PASS_WITH_LEGACY
-#define SWIFT_INSTRUCTION_PASS_WITH_LEGACY(Inst, Tag) \
-        SWIFT_INSTRUCTION_PASS(Inst, Tag)
-#endif
-
 /// PASS_RANGE(RANGE_ID, START, END)
 ///   Pass IDs between PassKind::START and PassKind::END, inclusive,
 ///   fall within the set known as
@@ -142,7 +121,7 @@ PASS(ArrayCountPropagation, "array-count-propagation",
      "Array Count Propagation")
 PASS(ArrayElementPropagation, "array-element-propagation",
      "Array Element Propagation")
-SWIFT_FUNCTION_PASS_WITH_LEGACY(AssumeSingleThreaded, "sil-assume-single-threaded",
+SWIFT_FUNCTION_PASS(AssumeSingleThreaded, "sil-assume-single-threaded",
      "Assume Single-Threaded Environment")
 PASS(BasicInstructionPropertyDumper, "basic-instruction-property-dump",
      "Print SIL Instruction MemBehavior and ReleaseBehavior Information")
@@ -326,7 +305,7 @@ PASS(MemBehaviorDumper, "mem-behavior-dump",
      "Print SIL Instruction MemBehavior from Alias Analysis over all Pairs")
 PASS(LSLocationPrinter, "lslocation-dump",
      "Print Load-Store Location Results Covering all Accesses")
-SWIFT_FUNCTION_PASS_WITH_LEGACY(MergeCondFails, "merge-cond_fails",
+SWIFT_FUNCTION_PASS(MergeCondFails, "merge-cond_fails",
      "Merge SIL cond_fail to Eliminate Redundant Overflow Checks")
 PASS(MoveCondFailToPreds, "move-cond-fail-to-preds",
      "Move SIL cond_fail by Hoisting Checks")
@@ -367,7 +346,7 @@ PASS(RedundantPhiElimination, "redundant-phi-elimination",
      "Redundant Phi Block Argument Elimination")
 PASS(PhiExpansion, "phi-expansion",
      "Replace Phi arguments by their only used field")
-SWIFT_FUNCTION_PASS_WITH_LEGACY(ReleaseDevirtualizer, "release-devirtualizer",
+SWIFT_FUNCTION_PASS(ReleaseDevirtualizer, "release-devirtualizer",
      "SIL release Devirtualization")
 PASS(RetainSinking, "retain-sinking",
      "SIL retain Sinking")
@@ -489,15 +468,13 @@ PASS(PruneVTables, "prune-vtables",
 PASS_RANGE(AllPasses, AADumper, PruneVTables)
 
 SWIFT_INSTRUCTION_PASS(BeginCOWMutationInst, "simplify-begin_cow_mutation")
-SWIFT_INSTRUCTION_PASS_WITH_LEGACY(GlobalValueInst, "simplify-global_value")
-SWIFT_INSTRUCTION_PASS_WITH_LEGACY(StrongRetainInst, "simplify-strong_retain")
-SWIFT_INSTRUCTION_PASS_WITH_LEGACY(StrongReleaseInst, "simplify-strong_release")
+SWIFT_INSTRUCTION_PASS(GlobalValueInst, "simplify-global_value")
+SWIFT_INSTRUCTION_PASS(StrongRetainInst, "simplify-strong_retain")
+SWIFT_INSTRUCTION_PASS(StrongReleaseInst, "simplify-strong_release")
 
 #undef IRGEN_PASS
 #undef SWIFT_MODULE_PASS
 #undef SWIFT_FUNCTION_PASS
-#undef SWIFT_FUNCTION_PASS_WITH_LEGACY
 #undef SWIFT_INSTRUCTION_PASS
-#undef SWIFT_INSTRUCTION_PASS_WITH_LEGACY
 #undef PASS
 #undef PASS_RANGE

include/swift/SILOptimizer/PassManager/Passes.h

@@ -76,9 +76,6 @@ namespace swift {
 
 #define PASS(ID, TAG, NAME) \
   SILTransform *create##ID();
-#define SWIFT_FUNCTION_PASS_WITH_LEGACY(ID, TAG, NAME) \
-  PASS(ID, TAG, NAME) \
-  SILTransform *createLegacy##ID();
 #define IRGEN_PASS(ID, TAG, NAME)
 #include "Passes.def"
 

lib/SILOptimizer/PassManager/Passes.cpp

@@ -304,14 +304,6 @@ SILTransform *swift::create##ID() { return new ID##Pass(); }               \
 SWIFT_FUNCTION_PASS_COMMON(ID, TAG)                                        \
 SILTransform *swift::create##ID() { return new ID##Pass(); }               \
 
-#define SWIFT_FUNCTION_PASS_WITH_LEGACY(ID, TAG, DESCRIPTION) \
-SWIFT_FUNCTION_PASS_COMMON(ID, TAG)                                        \
-SILTransform *swift::create##ID() {                                        \
-  if (passesRegistered)                                                    \
-    return new ID##Pass();                                                 \
-  return createLegacy##ID();                                               \
-}                                                                          \
-
 #include "swift/SILOptimizer/PassManager/Passes.def"
 
 #undef SWIFT_FUNCTION_PASS_COMMON

lib/SILOptimizer/SILCombiner/SILCombine.cpp

@@ -574,9 +574,6 @@ SILInstruction *SILCombiner::visit##INST(INST *inst) {                     \
 #define SWIFT_INSTRUCTION_PASS(INST, TAG) \
   SWIFT_INSTRUCTION_PASS_COMMON(INST, TAG, { return nullptr; })
 
-#define SWIFT_INSTRUCTION_PASS_WITH_LEGACY(INST, TAG) \
-  SWIFT_INSTRUCTION_PASS_COMMON(INST, TAG, { return legacyVisit##INST(inst); })
-
 #include "swift/SILOptimizer/PassManager/Passes.def"
 
 #undef SWIFT_INSTRUCTION_PASS_COMMON

lib/SILOptimizer/SILCombiner/SILCombiner.h

@@ -240,7 +240,6 @@ class SILCombiner :
   SILInstruction *optimizeStringObject(BuiltinInst *BI);
   SILInstruction *visitBuiltinInst(BuiltinInst *BI);
   SILInstruction *visitCondFailInst(CondFailInst *CFI);
-  SILInstruction *legacyVisitStrongRetainInst(StrongRetainInst *SRI);
   SILInstruction *visitCopyValueInst(CopyValueInst *cvi);
   SILInstruction *visitDestroyValueInst(DestroyValueInst *dvi);
   SILInstruction *visitRefToRawPointerInst(RefToRawPointerInst *RRPI);
@@ -270,7 +269,6 @@ class SILCombiner :
   SILInstruction *visitRawPointerToRefInst(RawPointerToRefInst *RPTR);
   SILInstruction *
   visitUncheckedTakeEnumDataAddrInst(UncheckedTakeEnumDataAddrInst *TEDAI);
-  SILInstruction *legacyVisitStrongReleaseInst(StrongReleaseInst *SRI);
   SILInstruction *visitCondBranchInst(CondBranchInst *CBI);
   SILInstruction *
   visitUncheckedTrivialBitCastInst(UncheckedTrivialBitCastInst *UTBCI);
@@ -298,8 +296,6 @@ class SILCombiner :
   visitConvertEscapeToNoEscapeInst(ConvertEscapeToNoEscapeInst *Cvt);
   SILInstruction *
   visitDifferentiableFunctionExtractInst(DifferentiableFunctionExtractInst *DFEI);
-  
-  SILInstruction *legacyVisitGlobalValueInst(GlobalValueInst *globalValue);
 
 #define PASS(ID, TAG, DESCRIPTION)
 #define SWIFT_FUNCTION_PASS(ID, TAG, DESCRIPTION)

lib/SILOptimizer/SILCombiner/SILCombinerMiscVisitors.cpp

@@ -1250,60 +1250,6 @@ SILInstruction *SILCombiner::visitDestroyValueInst(DestroyValueInst *dvi) {
   return nullptr;
 }
 
-SILInstruction *SILCombiner::legacyVisitStrongRetainInst(StrongRetainInst *SRI) {
-  assert(!SRI->getFunction()->hasOwnership());
-
-  // Retain of ThinToThickFunction is a no-op.
-  SILValue funcOper = SRI->getOperand();
-  if (auto *CFI = dyn_cast<ConvertFunctionInst>(funcOper))
-    funcOper = CFI->getOperand();
-
-  if (isa<ThinToThickFunctionInst>(funcOper))
-    return eraseInstFromFunction(*SRI);
-
-  if (isa<ObjCExistentialMetatypeToObjectInst>(SRI->getOperand()) ||
-      isa<ObjCMetatypeToObjectInst>(SRI->getOperand()))
-    return eraseInstFromFunction(*SRI);
-
-  // Retain and Release of tagged strings is a no-op.
-  // The builtin code pattern to find tagged strings is:
-  // builtin "stringObjectOr_Int64" (or to tag the string)
-  // value_to_bridge_object (cast the UInt to bridge object)
-  if (isa<ValueToBridgeObjectInst>(SRI->getOperand())) {
-    return eraseInstFromFunction(*SRI);
-  }
-
-  // Sometimes in the stdlib due to hand offs, we will see code like:
-  //
-  // strong_release %0
-  // strong_retain %0
-  //
-  // with the matching strong_retain to the strong_release in a predecessor
-  // basic block and the matching strong_release for the strong_retain in a
-  // successor basic block.
-  //
-  // Due to the matching pairs being in different basic blocks, the ARC
-  // Optimizer (which is currently local to one basic block does not handle
-  // it). But that does not mean that we cannot eliminate this pair with a
-  // peephole.
-
-  // If we are not the first instruction in this basic block...
-  if (SRI != &*SRI->getParent()->begin()) {
-    auto Pred = std::prev(SRI->getIterator());
-
-    // ...and the predecessor instruction is a strong_release on the same value
-    // as our strong_retain...
-    if (auto *Release = dyn_cast<StrongReleaseInst>(&*Pred))
-      // Remove them...
-      if (Release->getOperand() == SRI->getOperand()) {
-        eraseInstFromFunction(*Release);
-        return eraseInstFromFunction(*SRI);
-      }
-  }
-
-  return nullptr;
-}
-
 /// Create a value from stores to an address.
 ///
 /// If there are only stores to \p addr, return the stored value. Also, if there
@@ -1858,37 +1804,6 @@ SILInstruction *SILCombiner::visitUncheckedTakeEnumDataAddrInst(
   return eraseInstFromFunction(*tedai);
 }
 
-SILInstruction *SILCombiner::legacyVisitStrongReleaseInst(StrongReleaseInst *SRI) {
-  assert(!SRI->getFunction()->hasOwnership());
-
-  // Release of ThinToThickFunction is a no-op.
-  if (isa<ThinToThickFunctionInst>(SRI->getOperand()))
-    return eraseInstFromFunction(*SRI);
-
-  if (isa<ObjCExistentialMetatypeToObjectInst>(SRI->getOperand()) ||
-      isa<ObjCMetatypeToObjectInst>(SRI->getOperand()))
-    return eraseInstFromFunction(*SRI);
-
-  // Retain and Release of tagged strings is a no-op.
-  // The builtin code pattern to find tagged strings is:
-  // builtin "stringObjectOr_Int64" (or to tag the string)
-  // value_to_bridge_object (cast the UInt to bridge object)
-  if (isa<ValueToBridgeObjectInst>(SRI->getOperand())) {
-    return eraseInstFromFunction(*SRI);
-  }
-
-  // Release of a classbound existential converted from a class is just a
-  // release of the class, squish the conversion.
-  if (auto ier = dyn_cast<InitExistentialRefInst>(SRI->getOperand()))
-    if (ier->hasOneUse()) {
-      SRI->setOperand(ier->getOperand());
-      eraseInstFromFunction(*ier);
-      return SRI;
-    }
-  
-  return nullptr;
-}
-
 SILInstruction *SILCombiner::visitCondBranchInst(CondBranchInst *CBI) {
   // NOTE: All of the following optimizations do invalidates branches by
   // replacing the branches, but do not modify the underlying CFG properties
@@ -2411,20 +2326,6 @@ static bool checkGlobalValueUsers(SILValue val,
   return true;
 }
 
-SILInstruction *
-SILCombiner::legacyVisitGlobalValueInst(GlobalValueInst *globalValue) {
-  // Delete all reference count instructions on a global_value if the only other
-  // users are projections (ref_element_addr and ref_tail_addr).
-  SmallVector<SILInstruction *, 8> toDelete;
-  if (!checkGlobalValueUsers(globalValue, toDelete))
-    return nullptr;
-  for (SILInstruction *inst : toDelete) {
-    eraseInstFromFunction(*inst);
-  }
-  return nullptr;
-
-}
-
 // Simplify `differentiable_function_extract` of `differentiable_function`.
 //
 // Before:

lib/SILOptimizer/Transforms/AssumeSingleThreaded.cpp

@@ -7,7 +7,6 @@ target_sources(swiftSILOptimizer PRIVATE
   AllocBoxToStack.cpp
   ArrayCountPropagation.cpp
   ArrayElementValuePropagation.cpp
-  AssumeSingleThreaded.cpp
   COWOpts.cpp
   CSE.cpp
   ConditionForwarding.cpp
@@ -21,7 +20,6 @@ target_sources(swiftSILOptimizer PRIVATE
   DifferentiabilityWitnessDevirtualizer.cpp
   EagerSpecializer.cpp
   GenericSpecializer.cpp
-  MergeCondFail.cpp
   Outliner.cpp
   ObjectOutliner.cpp
   AssemblyVisionRemarkGenerator.cpp
@@ -31,7 +29,6 @@ target_sources(swiftSILOptimizer PRIVATE
   PruneVTables.cpp
   RedundantLoadElimination.cpp
   RedundantOverflowCheckRemoval.cpp
-  ReleaseDevirtualizer.cpp
   SILCodeMotion.cpp
   SILLowerAggregateInstrs.cpp
   SILMem2Reg.cpp