Remove select_value SIL instruction

Author: meg-gupta

docs/SIL.rst

@@ -3475,8 +3475,6 @@ A value ``%1`` is said to be *value-dependent* on a value ``%0`` if:
   with ``tuple_extract``, ``struct_extract``, ``unchecked_enum_data``,
   ``select_enum``, or ``select_enum_addr``.
 
-- ``%1`` is the result of ``select_value`` and ``%0`` is one of the cases.
-
 - ``%1`` is a basic block parameter and ``%0`` is the corresponding
   argument from a branch to that block.
 
@@ -7949,45 +7947,6 @@ block. If there is a ``default`` basic block, control is transferred to it if
 the value does not match any of the ``case`` values. It is undefined behavior
 if the value does not match any cases and no ``default`` branch is provided.
 
-select_value
-````````````
-::
-
-  sil-instruction ::= 'select_value' sil-operand sil-select-value-case*
-                      (',' 'default' sil-value)?
-                      ':' sil-type
-  sil-select-value-case ::= 'case' sil-value ':' sil-value
-
-
-  %n = select_value %0 : $U, \
-    case %c1: %r1,           \
-    case %c2: %r2, /* ... */ \
-    default %r3 : $T
-
-  // $U must be a builtin type. Only integers types are supported currently.
-  // c1, c2, etc must be of type $U
-  // %r1, %r2, %r3, etc. must have type $T
-  // %n has type $T
-
-Selects one of the "case" or "default" operands based on the case of a
-value. This is equivalent to a trivial `switch_value`_ branch sequence::
-
-  entry:
-    switch_value %0 : $U,            \
-      case %c1: bb1,           \
-      case %c2: bb2, /* ... */ \
-      default bb_default
-  bb1:
-    br cont(%r1 : $T) // value for %c1
-  bb2:
-    br cont(%r2 : $T) // value for %c2
-  bb_default:
-    br cont(%r3 : $T) // value for default
-  cont(%n : $T):
-    // use argument %n
-
-but turns the control flow dependency into a data flow dependency.
-
 switch_enum
 ```````````
 ::

include/swift/SIL/SILBuilder.h

@@ -1700,14 +1700,6 @@ class SILBuilder {
         getModule(), CaseCounts, DefaultCount));
   }
 
-  SelectValueInst *createSelectValue(
-      SILLocation Loc, SILValue Operand, SILType Ty, SILValue DefaultResult,
-      ArrayRef<std::pair<SILValue, SILValue>> CaseValuesAndResult) {
-    return insert(SelectValueInst::create(getSILDebugLocation(Loc), Operand, Ty,
-                                          DefaultResult, CaseValuesAndResult,
-                                          getModule()));
-  }
-
   TupleExtractInst *createTupleExtract(SILLocation Loc, SILValue Operand,
                                        unsigned FieldNo, SILType ResultTy) {
     return createTupleExtract(Loc, Operand, FieldNo, ResultTy,

include/swift/SIL/SILCloner.h

@@ -3213,24 +3213,6 @@ SILCloner<ImplClass>::visitSelectEnumAddrInst(SelectEnumAddrInst *Inst) {
                                     CaseResults));
 }
 
-template<typename ImplClass>
-void
-SILCloner<ImplClass>::visitSelectValueInst(SelectValueInst *Inst) {
-  SILValue DefaultResult;
-  if (Inst->hasDefault())
-    DefaultResult = getOpValue(Inst->getDefaultResult());
-  SmallVector<std::pair<SILValue, SILValue>, 8> CaseResults;
-  for (unsigned i = 0, e = Inst->getNumCases(); i != e; ++i)
-    CaseResults.push_back(std::make_pair(getOpValue(Inst->getCase(i).first),
-                                         getOpValue(Inst->getCase(i).second)));
-
-  getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
-  recordClonedInstruction(
-      Inst, getBuilder().createSelectValue(
-                getOpLocation(Inst->getLoc()), getOpValue(Inst->getOperand()),
-                getOpType(Inst->getType()), DefaultResult, CaseResults));
-}
-
 template <typename ImplClass>
 void SILCloner<ImplClass>::visitDynamicMethodBranchInst(
     DynamicMethodBranchInst *Inst) {

include/swift/SIL/SILInstruction.h

@@ -1392,7 +1392,6 @@ FirstArgOwnershipForwardingSingleValueInst::classof(SILInstructionKind kind) {
   case SILInstructionKind::ObjectInst:
   case SILInstructionKind::EnumInst:
   case SILInstructionKind::UncheckedEnumDataInst:
-  case SILInstructionKind::SelectValueInst:
   case SILInstructionKind::OpenExistentialRefInst:
   case SILInstructionKind::InitExistentialRefInst:
   case SILInstructionKind::MarkDependenceInst:
@@ -6581,8 +6580,8 @@ class UncheckedTakeEnumDataAddrInst
   }
 };
 
-// Abstract base class of all select instructions like select_enum,
-// select_value, etc. The template parameter represents a type of case values
+// Abstract base class of all select instructions like select_enum.
+// The template parameter represents a type of case values
 // to be compared with the operand of a select instruction.
 //
 // Subclasses must provide tail allocated storage.
@@ -6800,50 +6799,6 @@ class SelectEnumAddrInst final
          ProfileCounter DefaultCount);
 };
 
-/// Select on a value of a builtin integer type.
-///
-/// There is 'the' operand, followed by pairs of operands for each case,
-/// followed by an optional default operand.
-class SelectValueInst final
-    : public InstructionBaseWithTrailingOperands<
-          SILInstructionKind::SelectValueInst, SelectValueInst,
-          SelectInstBase<SelectValueInst, SILValue, SingleValueInstruction>> {
-  friend SILBuilder;
-
-  SelectValueInst(SILDebugLocation DebugLoc, SILValue Operand, SILType Type,
-                  SILValue DefaultResult,
-                  ArrayRef<SILValue> CaseValuesAndResults);
-
-  static SelectValueInst *
-  create(SILDebugLocation DebugLoc, SILValue Operand, SILType Type,
-         SILValue DefaultValue,
-         ArrayRef<std::pair<SILValue, SILValue>> CaseValues, SILModule &M);
-
-public:
-  std::pair<SILValue, SILValue>
-  getCase(unsigned i) const {
-    auto cases = getAllOperands().slice(1);
-    return {cases[i*2].get(), cases[i*2+1].get()};
-  }
-
-  unsigned getNumCases() const {
-    // Ignore the first non-case operand.
-    auto count = getAllOperands().size() - 1;
-    // This implicitly ignore the optional default operand.
-    return count / 2;
-  }
-
-  bool hasDefault() const {
-    // If the operand count is even, then we have a default value.
-    return (getAllOperands().size() & 1) == 0;
-  }
-
-  SILValue getDefaultResult() const {
-    assert(hasDefault() && "doesn't have a default");
-    return getAllOperands().back().get();
-  }
-};
-
 /// MetatypeInst - Represents the production of an instance of a given metatype
 /// named statically.
 class MetatypeInst final

include/swift/SIL/SILNodes.def

@@ -595,8 +595,6 @@ ABSTRACT_VALUE_AND_INST(SingleValueInstruction, ValueBase, SILInstruction)
                     SingleValueInstruction, None, DoesNotRelease)
   SINGLE_VALUE_INST(SelectEnumAddrInst, select_enum_addr,
                     SingleValueInstruction, MayRead, DoesNotRelease)
-  SINGLE_VALUE_INST(SelectValueInst, select_value,
-                    SingleValueInstruction, None, DoesNotRelease)
 
   // Protocol and Protocol Composition Types
   SINGLE_VALUE_INST(InitExistentialAddrInst, init_existential_addr,

lib/IRGen/IRGenSIL.cpp

@@ -1284,7 +1284,6 @@ class IRGenSILFunction :
   void visitInitEnumDataAddrInst(InitEnumDataAddrInst *i);
   void visitSelectEnumInst(SelectEnumInst *i);
   void visitSelectEnumAddrInst(SelectEnumAddrInst *i);
-  void visitSelectValueInst(SelectValueInst *i);
   void visitUncheckedEnumDataInst(UncheckedEnumDataInst *i);
   void visitUncheckedTakeEnumDataAddrInst(UncheckedTakeEnumDataAddrInst *i);
   void visitInjectEnumAddrInst(InjectEnumAddrInst *i);
@@ -4637,27 +4636,6 @@ void IRGenSILFunction::visitSelectEnumAddrInst(SelectEnumAddrInst *inst) {
     // emitBBMapForSelectEnum set up a phi node to receive the result.
     Builder.SetInsertPoint(contBB);
   }
-  
-  setLoweredValue(inst,
-                  getLoweredValueForSelect(*this, result, inst));
-}
-
-void IRGenSILFunction::visitSelectValueInst(SelectValueInst *inst) {
-  Explosion value = getLoweredExplosion(inst->getOperand());
-
-  // Map the SIL dest bbs to their LLVM bbs.
-  SmallVector<std::pair<SILValue, llvm::BasicBlock*>, 4> dests;
-  llvm::BasicBlock *defaultDest;
-  Explosion result;
-  auto *contBB = emitBBMapForSelect(*this, result, dests, defaultDest, inst);
-
-  // Emit the dispatch.
-  emitSwitchValueDispatch(*this, inst->getOperand()->getType(), value, dests,
-                          defaultDest);
-
-  // emitBBMapForSelectEnum set up a continuation block and phi nodes to
-  // receive the result.
-  Builder.SetInsertPoint(contBB);
 
   setLoweredValue(inst,
                   getLoweredValueForSelect(*this, result, inst));

lib/SIL/IR/OperandOwnership.cpp

@@ -186,8 +186,6 @@ OPERAND_OWNERSHIP(TrivialUse, PointerToAddress)
 OPERAND_OWNERSHIP(TrivialUse, ProjectBlockStorage)
 OPERAND_OWNERSHIP(TrivialUse, RawPointerToRef)
 OPERAND_OWNERSHIP(TrivialUse, SelectEnumAddr)
-// select_value is only supported for integer types currently.
-OPERAND_OWNERSHIP(TrivialUse, SelectValue)
 OPERAND_OWNERSHIP(TrivialUse, StructElementAddr)
 OPERAND_OWNERSHIP(TrivialUse, SwitchEnumAddr)
 OPERAND_OWNERSHIP(TrivialUse, SwitchValue)

lib/SIL/IR/SILInstruction.cpp

@@ -688,25 +688,6 @@ namespace {
       return visitSelectEnumInstBase(RHS);
     }
 
-    bool visitSelectValueInst(const SelectValueInst *RHS) {
-      // Check that the instructions match cases in the same order.
-      auto *X = cast<SelectValueInst>(LHS);
-
-      if (X->getNumCases() != RHS->getNumCases())
-        return false;
-      if (X->hasDefault() != RHS->hasDefault())
-        return false;
-
-      for (unsigned i = 0, e = X->getNumCases(); i < e; ++i) {
-        if (X->getCase(i).first != RHS->getCase(i).first)
-          return false;
-        if (X->getCase(i).second != RHS->getCase(i).second)
-          return false;
-      }
-
-      return true;
-    }
-
     // Conversion instructions.
     // All of these just return true as they have already had their
     // operands and types checked

lib/SIL/IR/SILInstructions.cpp

@@ -1914,35 +1914,6 @@ SwitchValueInst *SwitchValueInst::create(
   return ::new (buf) SwitchValueInst(Loc, Operand, DefaultBB, Cases, BBs);
 }
 
-SelectValueInst::SelectValueInst(SILDebugLocation DebugLoc, SILValue Operand,
-                                 SILType Type, SILValue DefaultResult,
-                                 ArrayRef<SILValue> CaseValuesAndResults)
-    : InstructionBaseWithTrailingOperands(Operand, CaseValuesAndResults,
-                                          DebugLoc, Type) {}
-
-SelectValueInst *
-SelectValueInst::create(SILDebugLocation Loc, SILValue Operand, SILType Type,
-                        SILValue DefaultResult,
-                        ArrayRef<std::pair<SILValue, SILValue>> CaseValues,
-                        SILModule &M) {
-  // Allocate enough room for the instruction with tail-allocated data for all
-  // the case values and the SILSuccessor arrays. There are `CaseBBs.size()`
-  // SILValues and `CaseBBs.size() + (DefaultBB ? 1 : 0)` successors.
-  SmallVector<SILValue, 8> CaseValuesAndResults;
-  for (auto pair : CaseValues) {
-    CaseValuesAndResults.push_back(pair.first);
-    CaseValuesAndResults.push_back(pair.second);
-  }
-
-  if ((bool)DefaultResult)
-    CaseValuesAndResults.push_back(DefaultResult);
-
-  auto Size = totalSizeToAlloc<swift::Operand>(CaseValuesAndResults.size() + 1);
-  auto Buf = M.allocateInst(Size, alignof(SelectValueInst));
-  return ::new (Buf)
-      SelectValueInst(Loc, Operand, Type, DefaultResult, CaseValuesAndResults);
-}
-
 template <typename SELECT_ENUM_INST>
 SELECT_ENUM_INST *SelectEnumInstBase::createSelectEnum(
     SILDebugLocation Loc, SILValue Operand, SILType Ty, SILValue DefaultValue,

lib/SIL/IR/SILPrinter.cpp

@@ -2669,21 +2669,6 @@ class SILPrinter : public SILInstructionVisitor<SILPrinter> {
     printSelectEnumInst(SEI);
   }
 
-  void visitSelectValueInst(SelectValueInst *SVI) {
-    *this << getIDAndType(SVI->getOperand());
-
-    for (unsigned i = 0, e = SVI->getNumCases(); i < e; ++i) {
-      SILValue casevalue;
-      SILValue result;
-      std::tie(casevalue, result) = SVI->getCase(i);
-      *this << ", case " << Ctx.getID(casevalue) << ": " << Ctx.getID(result);
-    }
-    if (SVI->hasDefault())
-      *this << ", default " << Ctx.getID(SVI->getDefaultResult());
-
-    *this << " : " << SVI->getType();
-  }
-  
   void visitDynamicMethodBranchInst(DynamicMethodBranchInst *DMBI) {
     *this << getIDAndType(DMBI->getOperand()) << ", " << DMBI->getMember()
           << ", " << Ctx.getID(DMBI->getHasMethodBB()) << ", "

lib/SIL/IR/ValueOwnership.cpp

@@ -132,7 +132,6 @@ CONSTANT_OWNERSHIP_INST(None, RefElementAddr)
 CONSTANT_OWNERSHIP_INST(None, RefTailAddr)
 CONSTANT_OWNERSHIP_INST(None, RefToRawPointer)
 CONSTANT_OWNERSHIP_INST(None, SelectEnumAddr)
-CONSTANT_OWNERSHIP_INST(None, SelectValue)
 CONSTANT_OWNERSHIP_INST(None, StringLiteral)
 CONSTANT_OWNERSHIP_INST(None, StructElementAddr)
 CONSTANT_OWNERSHIP_INST(None, SuperMethod)

lib/SIL/Parser/ParseSIL.cpp

@@ -5908,66 +5908,6 @@ bool SILParser::parseSpecificSILInstruction(SILBuilder &B,
       ResultVal = B.createSwitchValue(InstLoc, Val, DefaultBB, CaseBBs);
       break;
     }
-    case SILInstructionKind::SelectValueInst: {
-      if (parseTypedValueRef(Val, B))
-        return true;
-
-      SmallVector<std::pair<UnresolvedValueName, UnresolvedValueName>, 4>
-          CaseValueAndResultNames;
-      Optional<UnresolvedValueName> DefaultResultName;
-      while (P.consumeIf(tok::comma)) {
-        Identifier BBName;
-        SourceLoc BBLoc;
-        // Parse 'default' sil-value.
-        UnresolvedValueName tmp;
-        if (P.consumeIf(tok::kw_default)) {
-          if (parseValueName(tmp))
-            return true;
-          DefaultResultName = tmp;
-          break;
-        }
-
-        // Parse 'case' sil-decl-ref ':' sil-value.
-        if (P.consumeIf(tok::kw_case)) {
-          UnresolvedValueName casevalue;
-          parseValueName(casevalue);
-          P.parseToken(tok::colon, diag::expected_tok_in_sil_instr, ":");
-          parseValueName(tmp);
-          CaseValueAndResultNames.push_back(std::make_pair(casevalue, tmp));
-          continue;
-        }
-
-        P.diagnose(P.Tok, diag::expected_tok_in_sil_instr, "case or default");
-        return true;
-      }
-
-      if (!DefaultResultName) {
-        P.diagnose(P.Tok, diag::expected_tok_in_sil_instr, "default");
-        return true;
-      }
-
-      // Parse the type of the result operands.
-      SILType ResultType;
-      if (P.parseToken(tok::colon, diag::expected_tok_in_sil_instr, ":") ||
-          parseSILType(ResultType) || parseSILDebugLocation(InstLoc, B))
-        return true;
-
-      // Resolve the results.
-      SmallVector<std::pair<SILValue, SILValue>, 4> CaseValues;
-      SILValue DefaultValue;
-      if (DefaultResultName)
-        DefaultValue =
-            getLocalValue(*DefaultResultName, ResultType, InstLoc, B);
-      SILType ValType = Val->getType();
-      for (auto &caseName : CaseValueAndResultNames)
-        CaseValues.push_back(std::make_pair(
-            getLocalValue(caseName.first, ValType, InstLoc, B),
-            getLocalValue(caseName.second, ResultType, InstLoc, B)));
-
-      ResultVal = B.createSelectValue(InstLoc, Val, ResultType, DefaultValue,
-                                      CaseValues);
-      break;
-    }
     case SILInstructionKind::DeinitExistentialAddrInst: {
       if (parseTypedValueRef(Val, B) || parseSILDebugLocation(InstLoc, B))
         return true;

lib/SIL/Utils/InstructionUtils.cpp

@@ -466,7 +466,6 @@ RuntimeEffect swift::getRuntimeEffect(SILInstruction *inst, SILType &impactType)
   case SILInstructionKind::UncheckedTakeEnumDataAddrInst:
   case SILInstructionKind::SelectEnumInst:
   case SILInstructionKind::SelectEnumAddrInst:
-  case SILInstructionKind::SelectValueInst:
   case SILInstructionKind::OpenExistentialMetatypeInst:
   case SILInstructionKind::OpenExistentialBoxInst:
   case SILInstructionKind::OpenExistentialValueInst: