//===-- FIROps.cpp --------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "flang/Optimizer/Dialect/FIROps.h"
#include "flang/Optimizer/Dialect/FIRAttr.h"
#include "flang/Optimizer/Dialect/FIROpsSupport.h"
#include "flang/Optimizer/Dialect/FIRType.h"
#include "mlir/ADT/TypeSwitch.h"
#include "mlir/Dialect/StandardOps/IR/Ops.h"
#include "mlir/IR/Diagnostics.h"
#include "mlir/IR/Function.h"
#include "mlir/IR/Module.h"
#include "mlir/IR/StandardTypes.h"
#include "mlir/IR/SymbolTable.h"
#include "llvm/ADT/StringSwitch.h"

using namespace fir;

/// return true if the sequence type is abstract or the record type is malformed
/// or contains an abstract sequence type
static bool verifyInType(mlir::Type inType,
                         llvm::SmallVectorImpl<llvm::StringRef> &visited) {
  if (auto st = inType.dyn_cast<fir::SequenceType>()) {
    auto shape = st.getShape();
    if (shape.size() == 0)
      return true;
    for (auto ext : shape)
      if (ext < 0)
        return true;
  } else if (auto rt = inType.dyn_cast<fir::RecordType>()) {
    // don't recurse if we're already visiting this one
    if (llvm::is_contained(visited, rt.getName()))
      return false;
    // keep track of record types currently being visited
    visited.push_back(rt.getName());
    for (auto &field : rt.getTypeList())
      if (verifyInType(field.second, visited))
        return true;
    visited.pop_back();
  } else if (auto rt = inType.dyn_cast<fir::PointerType>()) {
    return verifyInType(rt.getEleTy(), visited);
  }
  return false;
}

static bool verifyRecordLenParams(mlir::Type inType, unsigned numLenParams) {
  if (numLenParams > 0) {
    if (auto rt = inType.dyn_cast<fir::RecordType>())
      return numLenParams != rt.getNumLenParams();
    return true;
  }
  return false;
}

//===----------------------------------------------------------------------===//
// AllocaOp
//===----------------------------------------------------------------------===//

mlir::Type fir::AllocaOp::getAllocatedType() {
  return getType().cast<ReferenceType>().getEleTy();
}

/// Create a legal memory reference as return type
mlir::Type fir::AllocaOp::wrapResultType(mlir::Type intype) {
  // FIR semantics: memory references to memory references are disallowed
  if (intype.isa<ReferenceType>())
    return {};
  return ReferenceType::get(intype);
}

mlir::Type fir::AllocaOp::getRefTy(mlir::Type ty) {
  return ReferenceType::get(ty);
}

//===----------------------------------------------------------------------===//
// AllocMemOp
//===----------------------------------------------------------------------===//

mlir::Type fir::AllocMemOp::getAllocatedType() {
  return getType().cast<HeapType>().getEleTy();
}

mlir::Type fir::AllocMemOp::getRefTy(mlir::Type ty) {
  return HeapType::get(ty);
}

/// Create a legal heap reference as return type
mlir::Type fir::AllocMemOp::wrapResultType(mlir::Type intype) {
  // Fortran semantics: C852 an entity cannot be both ALLOCATABLE and POINTER
  // 8.5.3 note 1 prohibits ALLOCATABLE procedures as well
  // FIR semantics: one may not allocate a memory reference value
  if (intype.isa<ReferenceType>() || intype.isa<HeapType>() ||
      intype.isa<PointerType>() || intype.isa<FunctionType>())
    return {};
  return HeapType::get(intype);
}

//===----------------------------------------------------------------------===//
// BoxDimsOp
//===----------------------------------------------------------------------===//

/// Get the result types packed in a tuple tuple
mlir::Type fir::BoxDimsOp::getTupleType() {
  // note: triple, but 4 is nearest power of 2
  llvm::SmallVector<mlir::Type, 4> triple{
      getResult(0).getType(), getResult(1).getType(), getResult(2).getType()};
  return mlir::TupleType::get(triple, getContext());
}

//===----------------------------------------------------------------------===//
// CallOp
//===----------------------------------------------------------------------===//

static void printCallOp(mlir::OpAsmPrinter &p, fir::CallOp &op) {
  auto callee = op.callee();
  bool isDirect = callee.hasValue();
  p << op.getOperationName() << ' ';
  if (isDirect)
    p << callee.getValue();
  else
    p << op.getOperand(0);
  p << '(' << op.getOperands().drop_front(isDirect ? 0 : 1) << ')';
  p.printOptionalAttrDict(op.getAttrs(), {fir::CallOp::calleeAttrName()});
  auto resultTypes{op.getResultTypes()};
  llvm::SmallVector<Type, 8> argTypes(
      llvm::drop_begin(op.getOperandTypes(), isDirect ? 0 : 1));
  p << " : " << FunctionType::get(argTypes, resultTypes, op.getContext());
}

static mlir::ParseResult parseCallOp(mlir::OpAsmParser &parser,
                                     mlir::OperationState &result) {
  llvm::SmallVector<mlir::OpAsmParser::OperandType, 8> operands;
  if (parser.parseOperandList(operands))
    return mlir::failure();

  llvm::SmallVector<mlir::NamedAttribute, 4> attrs;
  mlir::SymbolRefAttr funcAttr;
  bool isDirect = operands.empty();
  if (isDirect)
    if (parser.parseAttribute(funcAttr, fir::CallOp::calleeAttrName(), attrs))
      return mlir::failure();

  Type type;
  if (parser.parseOperandList(operands, mlir::OpAsmParser::Delimiter::Paren) ||
      parser.parseOptionalAttrDict(attrs) || parser.parseColon() ||
      parser.parseType(type))
    return mlir::failure();

  auto funcType = type.dyn_cast<mlir::FunctionType>();
  if (!funcType)
    return parser.emitError(parser.getNameLoc(), "expected function type");
  if (isDirect) {
    if (parser.resolveOperands(operands, funcType.getInputs(),
                               parser.getNameLoc(), result.operands))
      return mlir::failure();
  } else {
    auto funcArgs =
        llvm::ArrayRef<mlir::OpAsmParser::OperandType>(operands).drop_front();
    llvm::SmallVector<mlir::Value, 8> resultArgs(
        result.operands.begin() + (result.operands.empty() ? 0 : 1),
        result.operands.end());
    if (parser.resolveOperand(operands[0], funcType, result.operands) ||
        parser.resolveOperands(funcArgs, funcType.getInputs(),
                               parser.getNameLoc(), resultArgs))
      return mlir::failure();
  }
  result.addTypes(funcType.getResults());
  result.attributes = attrs;
  return mlir::success();
}

//===----------------------------------------------------------------------===//
// CmpfOp
//===----------------------------------------------------------------------===//

// Note: getCmpFPredicateNames() is inline static in StandardOps/IR/Ops.cpp
mlir::CmpFPredicate fir::CmpfOp::getPredicateByName(llvm::StringRef name) {
  auto pred = mlir::symbolizeCmpFPredicate(name);
  assert(pred.hasValue() && "invalid predicate name");
  return pred.getValue();
}

void fir::buildCmpFOp(Builder *builder, OperationState &result,
                      CmpFPredicate predicate, Value lhs, Value rhs) {
  result.addOperands({lhs, rhs});
  result.types.push_back(builder->getI1Type());
  result.addAttribute(
      CmpfOp::getPredicateAttrName(),
      builder->getI64IntegerAttr(static_cast<int64_t>(predicate)));
}

template <typename OPTY>
static void printCmpOp(OpAsmPrinter &p, OPTY op) {
  p << op.getOperationName() << ' ';
  auto predSym = mlir::symbolizeCmpFPredicate(
      op.template getAttrOfType<mlir::IntegerAttr>(OPTY::getPredicateAttrName())
          .getInt());
  assert(predSym.hasValue() && "invalid symbol value for predicate");
  p << '"' << mlir::stringifyCmpFPredicate(predSym.getValue()) << '"' << ", ";
  p.printOperand(op.lhs());
  p << ", ";
  p.printOperand(op.rhs());
  p.printOptionalAttrDict(op.getAttrs(),
                          /*elidedAttrs=*/{OPTY::getPredicateAttrName()});
  p << " : " << op.lhs().getType();
}

static void printCmpfOp(OpAsmPrinter &p, CmpfOp op) { printCmpOp(p, op); }

template <typename OPTY>
static mlir::ParseResult parseCmpOp(mlir::OpAsmParser &parser,
                                    mlir::OperationState &result) {
  llvm::SmallVector<mlir::OpAsmParser::OperandType, 2> ops;
  llvm::SmallVector<mlir::NamedAttribute, 4> attrs;
  mlir::Attribute predicateNameAttr;
  mlir::Type type;
  if (parser.parseAttribute(predicateNameAttr, OPTY::getPredicateAttrName(),
                            attrs) ||
      parser.parseComma() || parser.parseOperandList(ops, 2) ||
      parser.parseOptionalAttrDict(attrs) || parser.parseColonType(type) ||
      parser.resolveOperands(ops, type, result.operands))
    return failure();

  if (!predicateNameAttr.isa<mlir::StringAttr>())
    return parser.emitError(parser.getNameLoc(),
                            "expected string comparison predicate attribute");

  // Rewrite string attribute to an enum value.
  llvm::StringRef predicateName =
      predicateNameAttr.cast<mlir::StringAttr>().getValue();
  auto predicate = fir::CmpfOp::getPredicateByName(predicateName);
  auto builder = parser.getBuilder();
  mlir::Type i1Type = builder.getI1Type();
  attrs[0].second = builder.getI64IntegerAttr(static_cast<int64_t>(predicate));
  result.attributes = attrs;
  result.addTypes({i1Type});
  return success();
}

mlir::ParseResult fir::parseCmpfOp(mlir::OpAsmParser &parser,
                                   mlir::OperationState &result) {
  return parseCmpOp<fir::CmpfOp>(parser, result);
}

//===----------------------------------------------------------------------===//
// CmpcOp
//===----------------------------------------------------------------------===//

void fir::buildCmpCOp(Builder *builder, OperationState &result,
                      CmpFPredicate predicate, Value lhs, Value rhs) {
  result.addOperands({lhs, rhs});
  result.types.push_back(builder->getI1Type());
  result.addAttribute(
      fir::CmpcOp::getPredicateAttrName(),
      builder->getI64IntegerAttr(static_cast<int64_t>(predicate)));
}

static void printCmpcOp(OpAsmPrinter &p, fir::CmpcOp op) { printCmpOp(p, op); }

mlir::ParseResult fir::parseCmpcOp(mlir::OpAsmParser &parser,
                                   mlir::OperationState &result) {
  return parseCmpOp<fir::CmpcOp>(parser, result);
}

//===----------------------------------------------------------------------===//
// DispatchOp
//===----------------------------------------------------------------------===//

mlir::FunctionType fir::DispatchOp::getFunctionType() {
  auto attr = getAttr("fn_type").cast<mlir::TypeAttr>();
  return attr.getValue().cast<mlir::FunctionType>();
}

//===----------------------------------------------------------------------===//
// DispatchTableOp
//===----------------------------------------------------------------------===//

void fir::DispatchTableOp::appendTableEntry(mlir::Operation *op) {
  assert(mlir::isa<fir::DTEntryOp>(*op) && "operation must be a DTEntryOp");
  auto &block = getBlock();
  block.getOperations().insert(block.end(), op);
}

//===----------------------------------------------------------------------===//
// EmboxOp
//===----------------------------------------------------------------------===//

static mlir::ParseResult parseEmboxOp(mlir::OpAsmParser &parser,
                                      mlir::OperationState &result) {
  mlir::FunctionType type;
  llvm::SmallVector<mlir::OpAsmParser::OperandType, 8> operands;
  mlir::OpAsmParser::OperandType memref;
  if (parser.parseOperand(memref))
    return mlir::failure();
  operands.push_back(memref);
  auto &builder = parser.getBuilder();
  if (!parser.parseOptionalLParen()) {
    if (parser.parseOperandList(operands, mlir::OpAsmParser::Delimiter::None) ||
        parser.parseRParen())
      return mlir::failure();
    auto lens = builder.getI32IntegerAttr(operands.size());
    result.addAttribute(fir::EmboxOp::lenpName(), lens);
  }
  if (!parser.parseOptionalComma()) {
    mlir::OpAsmParser::OperandType dims;
    if (parser.parseOperand(dims))
      return mlir::failure();
    operands.push_back(dims);
  } else if (!parser.parseOptionalLSquare()) {
    mlir::AffineMapAttr map;
    if (parser.parseAttribute(map, fir::EmboxOp::layoutName(),
                              result.attributes) ||
        parser.parseRSquare())
      return mlir::failure();
  }
  if (parser.parseOptionalAttrDict(result.attributes) ||
      parser.parseColonType(type) ||
      parser.resolveOperands(operands, type.getInputs(), parser.getNameLoc(),
                             result.operands) ||
      parser.addTypesToList(type.getResults(), result.types))
    return mlir::failure();
  return mlir::success();
}

//===----------------------------------------------------------------------===//
// GenTypeDescOp
//===----------------------------------------------------------------------===//

void fir::GenTypeDescOp::build(Builder *, OperationState &result,
                               mlir::TypeAttr inty) {
  result.addAttribute("in_type", inty);
  result.addTypes(TypeDescType::get(inty.getValue()));
}

//===----------------------------------------------------------------------===//
// GlobalOp
//===----------------------------------------------------------------------===//

void fir::GlobalOp::appendInitialValue(mlir::Operation *op) {
  getBlock().getOperations().push_back(op);
}

//===----------------------------------------------------------------------===//
// LoadOp
//===----------------------------------------------------------------------===//

/// Get the element type of a reference like type; otherwise null
static mlir::Type elementTypeOf(mlir::Type ref) {
  return mlir::TypeSwitch<mlir::Type, mlir::Type>(ref)
      .Case<ReferenceType, PointerType, HeapType>(
          [](auto type) { return type.getEleTy(); })
      .Default([](mlir::Type) { return mlir::Type{}; });
}

mlir::ParseResult fir::LoadOp::getElementOf(mlir::Type &ele, mlir::Type ref) {
  if ((ele = elementTypeOf(ref)))
    return mlir::success();
  return mlir::failure();
}

//===----------------------------------------------------------------------===//
// LoopOp
//===----------------------------------------------------------------------===//

void fir::LoopOp::build(mlir::Builder *builder, OperationState &result,
                        mlir::Value lb, mlir::Value ub, ValueRange step,
                        ArrayRef<NamedAttribute> attributes) {
  if (step.empty())
    result.addOperands({lb, ub});
  else
    result.addOperands({lb, ub, step[0]});
  mlir::Region *bodyRegion = result.addRegion();
  LoopOp::ensureTerminator(*bodyRegion, *builder, result.location);
  bodyRegion->front().addArgument(builder->getIndexType());
  result.addAttributes(attributes);
  NamedAttributeList attrs(attributes);
  if (!attrs.get(unorderedAttrName()))
    result.addTypes(builder->getIndexType());
}

static mlir::ParseResult parseLoopOp(mlir::OpAsmParser &parser,
                                     mlir::OperationState &result) {
  auto &builder = parser.getBuilder();
  OpAsmParser::OperandType inductionVariable, lb, ub, step;
  // Parse the induction variable followed by '='.
  if (parser.parseRegionArgument(inductionVariable) || parser.parseEqual())
    return mlir::failure();

  // Parse loop bounds.
  mlir::Type indexType = builder.getIndexType();
  if (parser.parseOperand(lb) ||
      parser.resolveOperand(lb, indexType, result.operands) ||
      parser.parseKeyword("to") || parser.parseOperand(ub) ||
      parser.resolveOperand(ub, indexType, result.operands))
    return mlir::failure();

  if (parser.parseOptionalKeyword(fir::LoopOp::stepAttrName())) {
    result.addAttribute(fir::LoopOp::stepAttrName(),
                        builder.getIntegerAttr(builder.getIndexType(), 1));
  } else if (parser.parseOperand(step) ||
             parser.resolveOperand(step, indexType, result.operands)) {
    return mlir::failure();
  }

  // Parse the optional `unordered` keyword
  bool isUnordered = false;
  if (!parser.parseOptionalKeyword(LoopOp::unorderedAttrName())) {
    result.addAttribute(LoopOp::unorderedAttrName(), builder.getUnitAttr());
    isUnordered = true;
  }

  // Parse the body region.
  mlir::Region *body = result.addRegion();
  if (parser.parseRegion(*body, inductionVariable, indexType))
    return mlir::failure();

  fir::LoopOp::ensureTerminator(*body, builder, result.location);

  // Parse the optional attribute list.
  if (parser.parseOptionalAttrDict(result.attributes))
    return mlir::failure();
  if (!isUnordered)
    result.addTypes(builder.getIndexType());
  return mlir::success();
}

fir::LoopOp fir::getForInductionVarOwner(mlir::Value val) {
  auto ivArg = val.dyn_cast<mlir::BlockArgument>();
  if (!ivArg)
    return {};
  assert(ivArg.getOwner() && "unlinked block argument");
  auto *containingInst = ivArg.getOwner()->getParentOp();
  return dyn_cast_or_null<fir::LoopOp>(containingInst);
}

//===----------------------------------------------------------------------===//
// SelectOp
//===----------------------------------------------------------------------===//

static constexpr llvm::StringRef getCompareOffsetAttr() {
  return "compare_operand_offsets";
}

static constexpr llvm::StringRef getTargetOffsetAttr() {
  return "target_operand_offsets";
}

template <typename A>
static A getSubOperands(unsigned pos, A allArgs,
                        mlir::DenseIntElementsAttr ranges) {
  unsigned start = 0;
  for (unsigned i = 0; i < pos; ++i)
    start += (*(ranges.begin() + i)).getZExtValue();
  unsigned end = start + (*(ranges.begin() + pos)).getZExtValue();
  return {std::next(allArgs.begin(), start), std::next(allArgs.begin(), end)};
}

llvm::Optional<mlir::OperandRange> fir::SelectOp::getCompareOperands(unsigned) {
  return {};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectOp::getCompareOperands(llvm::ArrayRef<mlir::Value>, unsigned) {
  return {};
}

llvm::Optional<mlir::OperandRange>
fir::SelectOp::getSuccessorOperands(unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  return {getSubOperands(oper, targetArgs(), a)};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectOp::getSuccessorOperands(llvm::ArrayRef<mlir::Value> operands,
                                    unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  auto segments =
      getAttrOfType<mlir::DenseIntElementsAttr>(getOperandSegmentSizeAttr());
  return {getSubOperands(oper, getSubOperands(2, operands, segments), a)};
}

bool fir::SelectOp::canEraseSuccessorOperand() { return true; }

//===----------------------------------------------------------------------===//
// SelectCaseOp
//===----------------------------------------------------------------------===//

llvm::Optional<mlir::OperandRange>
fir::SelectCaseOp::getCompareOperands(unsigned cond) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getCompareOffsetAttr());
  return {getSubOperands(cond, compareArgs(), a)};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectCaseOp::getCompareOperands(llvm::ArrayRef<mlir::Value> operands,
                                      unsigned cond) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getCompareOffsetAttr());
  auto segments =
      getAttrOfType<mlir::DenseIntElementsAttr>(getOperandSegmentSizeAttr());
  return {getSubOperands(cond, getSubOperands(1, operands, segments), a)};
}

llvm::Optional<mlir::OperandRange>
fir::SelectCaseOp::getSuccessorOperands(unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  return {getSubOperands(oper, targetArgs(), a)};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectCaseOp::getSuccessorOperands(llvm::ArrayRef<mlir::Value> operands,
                                        unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  auto segments =
      getAttrOfType<mlir::DenseIntElementsAttr>(getOperandSegmentSizeAttr());
  return {getSubOperands(oper, getSubOperands(2, operands, segments), a)};
}

bool fir::SelectCaseOp::canEraseSuccessorOperand() { return true; }

// parser for fir.select_case Op
static mlir::ParseResult parseSelectCase(mlir::OpAsmParser &parser,
                                         mlir::OperationState &result) {
  mlir::OpAsmParser::OperandType selector;
  mlir::Type type;
  if (parseSelector(parser, result, selector, type))
    return mlir::failure();

  llvm::SmallVector<mlir::Attribute, 8> attrs;
  llvm::SmallVector<mlir::OpAsmParser::OperandType, 8> opers;
  llvm::SmallVector<mlir::Block *, 8> dests;
  llvm::SmallVector<llvm::SmallVector<mlir::Value, 8>, 8> destArgs;
  llvm::SmallVector<int32_t, 8> argOffs;
  int32_t offSize = 0;
  while (true) {
    mlir::Attribute attr;
    mlir::Block *dest;
    llvm::SmallVector<mlir::Value, 8> destArg;
    llvm::SmallVector<mlir::NamedAttribute, 1> temp;
    if (parser.parseAttribute(attr, "a", temp) || isValidCaseAttr(attr) ||
        parser.parseComma())
      return mlir::failure();
    attrs.push_back(attr);
    if (attr.dyn_cast_or_null<mlir::UnitAttr>()) {
      argOffs.push_back(0);
    } else if (attr.dyn_cast_or_null<fir::ClosedIntervalAttr>()) {
      mlir::OpAsmParser::OperandType oper1;
      mlir::OpAsmParser::OperandType oper2;
      if (parser.parseOperand(oper1) || parser.parseComma() ||
          parser.parseOperand(oper2) || parser.parseComma())
        return mlir::failure();
      opers.push_back(oper1);
      opers.push_back(oper2);
      argOffs.push_back(2);
      offSize += 2;
    } else {
      mlir::OpAsmParser::OperandType oper;
      if (parser.parseOperand(oper) || parser.parseComma())
        return mlir::failure();
      opers.push_back(oper);
      argOffs.push_back(1);
      ++offSize;
    }
    if (parser.parseSuccessorAndUseList(dest, destArg))
      return mlir::failure();
    dests.push_back(dest);
    destArgs.push_back(destArg);
    if (!parser.parseOptionalRSquare())
      break;
    if (parser.parseComma())
      return mlir::failure();
  }
  result.addAttribute(fir::SelectCaseOp::getCasesAttr(),
                      parser.getBuilder().getArrayAttr(attrs));
  if (parser.resolveOperands(opers, type, result.operands))
    return mlir::failure();
  llvm::SmallVector<int32_t, 8> targOffs;
  int32_t toffSize = 0;
  const auto count = dests.size();
  for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {
    result.addSuccessors(dests[i]);
    result.addOperands(destArgs[i]);
    auto argSize = destArgs[i].size();
    targOffs.push_back(argSize);
    toffSize += argSize;
  }
  auto &bld = parser.getBuilder();
  result.addAttribute(fir::SelectCaseOp::getOperandSegmentSizeAttr(),
                      bld.getI32VectorAttr({1, offSize, toffSize}));
  result.addAttribute(getCompareOffsetAttr(), bld.getI32VectorAttr(argOffs));
  result.addAttribute(getTargetOffsetAttr(), bld.getI32VectorAttr(targOffs));
  return mlir::success();
}

//===----------------------------------------------------------------------===//
// SelectRankOp
//===----------------------------------------------------------------------===//

llvm::Optional<mlir::OperandRange>
fir::SelectRankOp::getCompareOperands(unsigned) {
  return {};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectRankOp::getCompareOperands(llvm::ArrayRef<mlir::Value>, unsigned) {
  return {};
}

llvm::Optional<mlir::OperandRange>
fir::SelectRankOp::getSuccessorOperands(unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  return {getSubOperands(oper, targetArgs(), a)};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectRankOp::getSuccessorOperands(llvm::ArrayRef<mlir::Value> operands,
                                        unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  auto segments =
      getAttrOfType<mlir::DenseIntElementsAttr>(getOperandSegmentSizeAttr());
  return {getSubOperands(oper, getSubOperands(2, operands, segments), a)};
}

bool fir::SelectRankOp::canEraseSuccessorOperand() { return true; }

//===----------------------------------------------------------------------===//
// SelectTypeOp
//===----------------------------------------------------------------------===//

llvm::Optional<mlir::OperandRange>
fir::SelectTypeOp::getCompareOperands(unsigned) {
  return {};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectTypeOp::getCompareOperands(llvm::ArrayRef<mlir::Value>, unsigned) {
  return {};
}

llvm::Optional<mlir::OperandRange>
fir::SelectTypeOp::getSuccessorOperands(unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  return {getSubOperands(oper, targetArgs(), a)};
}

llvm::Optional<llvm::ArrayRef<mlir::Value>>
fir::SelectTypeOp::getSuccessorOperands(llvm::ArrayRef<mlir::Value> operands,
                                        unsigned oper) {
  auto a = getAttrOfType<mlir::DenseIntElementsAttr>(getTargetOffsetAttr());
  auto segments =
      getAttrOfType<mlir::DenseIntElementsAttr>(getOperandSegmentSizeAttr());
  return {getSubOperands(oper, getSubOperands(2, operands, segments), a)};
}

bool fir::SelectTypeOp::canEraseSuccessorOperand() { return true; }

static ParseResult parseSelectType(OpAsmParser &parser,
                                   OperationState &result) {
  mlir::OpAsmParser::OperandType selector;
  mlir::Type type;
  if (parseSelector(parser, result, selector, type))
    return mlir::failure();

  llvm::SmallVector<mlir::Attribute, 8> attrs;
  llvm::SmallVector<mlir::Block *, 8> dests;
  llvm::SmallVector<llvm::SmallVector<mlir::Value, 8>, 8> destArgs;
  while (true) {
    mlir::Attribute attr;
    mlir::Block *dest;
    llvm::SmallVector<mlir::Value, 8> destArg;
    llvm::SmallVector<mlir::NamedAttribute, 1> temp;
    if (parser.parseAttribute(attr, "a", temp) || parser.parseComma() ||
        parser.parseSuccessorAndUseList(dest, destArg))
      return mlir::failure();
    attrs.push_back(attr);
    dests.push_back(dest);
    destArgs.push_back(destArg);
    if (!parser.parseOptionalRSquare())
      break;
    if (parser.parseComma())
      return mlir::failure();
  }
  auto &bld = parser.getBuilder();
  result.addAttribute(fir::SelectTypeOp::getCasesAttr(),
                      bld.getArrayAttr(attrs));
  llvm::SmallVector<int32_t, 8> argOffs;
  int32_t offSize = 0;
  const auto count = dests.size();
  for (std::remove_const_t<decltype(count)> i = 0; i != count; ++i) {
    result.addSuccessors(dests[i]);
    result.addOperands(destArgs[i]);
    auto argSize = destArgs[i].size();
    argOffs.push_back(argSize);
    offSize += argSize;
  }
  result.addAttribute(fir::SelectTypeOp::getOperandSegmentSizeAttr(),
                      bld.getI32VectorAttr({1, 0, offSize}));
  result.addAttribute(getTargetOffsetAttr(), bld.getI32VectorAttr(argOffs));
  return mlir::success();
}

//===----------------------------------------------------------------------===//
// StoreOp
//===----------------------------------------------------------------------===//

mlir::Type fir::StoreOp::elementType(mlir::Type refType) {
  if (auto ref = refType.dyn_cast<ReferenceType>())
    return ref.getEleTy();
  if (auto ref = refType.dyn_cast<PointerType>())
    return ref.getEleTy();
  if (auto ref = refType.dyn_cast<HeapType>())
    return ref.getEleTy();
  return {};
}

//===----------------------------------------------------------------------===//
// StringLitOp
//===----------------------------------------------------------------------===//

bool fir::StringLitOp::isWideValue() {
  auto eleTy = getType().cast<fir::SequenceType>().getEleTy();
  return eleTy.cast<fir::CharacterType>().getFKind() != 1;
}

//===----------------------------------------------------------------------===//
// WhereOp
//===----------------------------------------------------------------------===//

void fir::WhereOp::build(mlir::Builder *builder, OperationState &result,
                         mlir::Value cond, bool withElseRegion) {
  result.addOperands(cond);
  mlir::Region *thenRegion = result.addRegion();
  mlir::Region *elseRegion = result.addRegion();
  WhereOp::ensureTerminator(*thenRegion, *builder, result.location);
  if (withElseRegion)
    WhereOp::ensureTerminator(*elseRegion, *builder, result.location);
}

static mlir::ParseResult parseWhereOp(OpAsmParser &parser,
                                      OperationState &result) {
  result.regions.reserve(2);
  mlir::Region *thenRegion = result.addRegion();
  mlir::Region *elseRegion = result.addRegion();

  auto &builder = parser.getBuilder();
  OpAsmParser::OperandType cond;
  mlir::Type i1Type = builder.getIntegerType(1);
  if (parser.parseOperand(cond) ||
      parser.resolveOperand(cond, i1Type, result.operands))
    return mlir::failure();

  if (parser.parseRegion(*thenRegion, {}, {}))
    return mlir::failure();

  WhereOp::ensureTerminator(*thenRegion, parser.getBuilder(), result.location);

  if (!parser.parseOptionalKeyword("otherwise")) {
    if (parser.parseRegion(*elseRegion, {}, {}))
      return mlir::failure();
    WhereOp::ensureTerminator(*elseRegion, parser.getBuilder(),
                              result.location);
  }

  // Parse the optional attribute list.
  if (parser.parseOptionalAttrDict(result.attributes))
    return mlir::failure();

  return mlir::success();
}

//===----------------------------------------------------------------------===//

mlir::ParseResult fir::isValidCaseAttr(mlir::Attribute attr) {
  if (attr.dyn_cast_or_null<mlir::UnitAttr>() ||
      attr.dyn_cast_or_null<ClosedIntervalAttr>() ||
      attr.dyn_cast_or_null<PointIntervalAttr>() ||
      attr.dyn_cast_or_null<LowerBoundAttr>() ||
      attr.dyn_cast_or_null<UpperBoundAttr>())
    return mlir::success();
  return mlir::failure();
}

unsigned fir::getCaseArgumentOffset(llvm::ArrayRef<mlir::Attribute> cases,
                                    unsigned dest) {
  unsigned o = 0;
  for (unsigned i = 0; i < dest; ++i) {
    auto &attr = cases[i];
    if (!attr.dyn_cast_or_null<mlir::UnitAttr>()) {
      ++o;
      if (attr.dyn_cast_or_null<ClosedIntervalAttr>())
        ++o;
    }
  }
  return o;
}

mlir::ParseResult fir::parseSelector(mlir::OpAsmParser &parser,
                                     mlir::OperationState &result,
                                     mlir::OpAsmParser::OperandType &selector,
                                     mlir::Type &type) {
  if (parser.parseOperand(selector) || parser.parseColonType(type) ||
      parser.resolveOperand(selector, type, result.operands) ||
      parser.parseLSquare())
    return mlir::failure();
  return mlir::success();
}

/// Generic pretty-printer of a binary operation
static void printBinaryOp(Operation *op, OpAsmPrinter &p) {
  assert(op->getNumOperands() == 2 && "binary op must have two operands");
  assert(op->getNumResults() == 1 && "binary op must have one result");

  p << op->getName() << ' ' << op->getOperand(0) << ", " << op->getOperand(1);
  p.printOptionalAttrDict(op->getAttrs());
  p << " : " << op->getResult(0).getType();
}

/// Generic pretty-printer of an unary operation
static void printUnaryOp(Operation *op, OpAsmPrinter &p) {
  assert(op->getNumOperands() == 1 && "unary op must have one operand");
  assert(op->getNumResults() == 1 && "unary op must have one result");

  p << op->getName() << ' ' << op->getOperand(0);
  p.printOptionalAttrDict(op->getAttrs());
  p << " : " << op->getResult(0).getType();
}

bool fir::isReferenceLike(mlir::Type type) {
  return type.isa<fir::ReferenceType>() || type.isa<fir::HeapType>() ||
         type.isa<fir::PointerType>();
}

mlir::FuncOp fir::createFuncOp(mlir::Location loc, mlir::ModuleOp module,
                               StringRef name, mlir::FunctionType type,
                               llvm::ArrayRef<mlir::NamedAttribute> attrs) {
  if (auto f = module.lookupSymbol<mlir::FuncOp>(name))
    return f;
  mlir::OpBuilder modBuilder(module.getBodyRegion());
  return modBuilder.create<mlir::FuncOp>(loc, name, type, attrs);
}

fir::GlobalOp fir::createGlobalOp(mlir::Location loc, mlir::ModuleOp module,
                                  StringRef name, mlir::Type type,
                                  llvm::ArrayRef<mlir::NamedAttribute> attrs) {
  if (auto g = module.lookupSymbol<fir::GlobalOp>(name))
    return g;
  mlir::OpBuilder modBuilder(module.getBodyRegion());
  return modBuilder.create<fir::GlobalOp>(loc, name, type, attrs);
}

namespace fir {

// Tablegen operators

#define GET_OP_CLASSES
#include "flang/Optimizer/Dialect/FIROps.cpp.inc"

} // namespace fir