ArithToSPIRV.cpp

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//===- ArithToSPIRV.cpp - Arithmetic to SPIRV dialect conversion -----===//
//
// 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 "mlir/Conversion/ArithToSPIRV/ArithToSPIRV.h"
 
#include "../SPIRVCommon/Pattern.h"
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/SPIRV/IR/SPIRVAttributes.h"
#include "mlir/Dialect/SPIRV/IR/SPIRVDialect.h"
#include "mlir/Dialect/SPIRV/IR/SPIRVOps.h"
#include "mlir/Dialect/SPIRV/IR/SPIRVTypes.h"
#include "mlir/Dialect/SPIRV/Transforms/SPIRVConversion.h"
#include "mlir/IR/BuiltinAttributes.h"
#include "mlir/IR/BuiltinTypes.h"
#include "mlir/IR/DialectResourceBlobManager.h"
#include "llvm/ADT/APInt.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include <cassert>
#include <memory>
 
namespace mlir {
#define GEN_PASS_DEF_CONVERTARITHTOSPIRVPASS
#include "mlir/Conversion/Passes.h.inc"
} // namespace mlir
 
#define DEBUG_TYPE "arith-to-spirv-pattern"
 
using namespace mlir;
 
//===----------------------------------------------------------------------===//
// Conversion Helpers
//===----------------------------------------------------------------------===//
 
/// Converts the given `srcAttr` into a boolean attribute if it holds an
/// integral value. Returns null attribute if conversion fails.
static BoolAttr convertBoolAttr(Attribute srcAttr, Builder builder) {
  if (auto boolAttr = dyn_cast<BoolAttr>(srcAttr))
    return boolAttr;
  if (auto intAttr = dyn_cast<IntegerAttr>(srcAttr))
    return builder.getBoolAttr(intAttr.getValue().getBoolValue());
  return {};
}
 
/// Converts the given `srcAttr` to a new attribute of the given `dstType`.
/// Returns null attribute if conversion fails.
static IntegerAttr convertIntegerAttr(IntegerAttr srcAttr, IntegerType dstType,
                                      Builder builder) {
  // If the source number uses less active bits than the target bitwidth, then
  // it should be safe to convert.
  if (srcAttr.getValue().isIntN(dstType.getWidth()))
    return builder.getIntegerAttr(dstType, srcAttr.getInt());
 
  // XXX: Try again by interpreting the source number as a signed value.
  // Although integers in the standard dialect are signless, they can represent
  // a signed number. It's the operation decides how to interpret. This is
  // dangerous, but it seems there is no good way of handling this if we still
  // want to change the bitwidth. Emit a message at least.
  if (srcAttr.getValue().isSignedIntN(dstType.getWidth())) {
    auto dstAttr = builder.getIntegerAttr(dstType, srcAttr.getInt());
    LLVM_DEBUG(llvm::dbgs() << "attribute '" << srcAttr << "' converted to '"
                            << dstAttr << "' for type '" << dstType << "'\n");
    return dstAttr;
  }
 
  LLVM_DEBUG(llvm::dbgs() << "attribute '" << srcAttr
                          << "' illegal: cannot fit into target type '"
                          << dstType << "'\n");
  return {};
}
 
/// Converts the given `srcAttr` to a new attribute of the given `dstType`.
/// Returns null attribute if `dstType` is not 32-bit or conversion fails.
static FloatAttr convertFloatAttr(FloatAttr srcAttr, FloatType dstType,
                                  Builder builder) {
  // Only support converting to float for now.
  if (!dstType.isF32())
    return FloatAttr();
 
  // Try to convert the source floating-point number to single precision.
  APFloat dstVal = srcAttr.getValue();
  bool losesInfo = false;
  APFloat::opStatus status =
      dstVal.convert(APFloat::IEEEsingle(), APFloat::rmTowardZero, &losesInfo);
  if (status != APFloat::opOK || losesInfo) {
    LLVM_DEBUG(llvm::dbgs()
               << srcAttr << " illegal: cannot fit into converted type '"
               << dstType << "'\n");
    return FloatAttr();
  }
 
  return builder.getF32FloatAttr(dstVal.convertToFloat());
}
 
// Get in IntegerAttr from FloatAttr while preserving the bits.
// Useful for converting float constants to integer constants while preserving
// the bits.
static IntegerAttr
getIntegerAttrFromFloatAttr(FloatAttr floatAttr, Type dstType,
                            ConversionPatternRewriter &rewriter) {
  APFloat floatVal = floatAttr.getValue();
  APInt intVal = floatVal.bitcastToAPInt();
  return rewriter.getIntegerAttr(dstType, intVal);
}
 
/// Returns true if the given `type` is a boolean scalar or vector type.
static bool isBoolScalarOrVector(Type type) {
  assert(type && "Not a valid type");
  if (type.isInteger(1))
    return true;
 
  if (auto vecType = dyn_cast<VectorType>(type))
    return vecType.getElementType().isInteger(1);
 
  return false;
}
 
/// Creates a scalar/vector integer constant.
static Value getScalarOrVectorConstInt(Type type, uint64_t value,
                                       OpBuilder &builder, Location loc) {
  if (auto vectorType = dyn_cast<VectorType>(type)) {
    Attribute element = IntegerAttr::get(vectorType.getElementType(), value);
    auto attr = SplatElementsAttr::get(vectorType, element);
    return spirv::ConstantOp::create(builder, loc, vectorType, attr);
  }
 
  if (auto intType = dyn_cast<IntegerType>(type))
    return spirv::ConstantOp::create(builder, loc, type,
                                     builder.getIntegerAttr(type, value));
 
  return nullptr;
}
 
/// Returns true if scalar/vector type `a` and `b` have the same number of
/// bitwidth.
static bool hasSameBitwidth(Type a, Type b) {
  auto getNumBitwidth = [](Type type) {
    unsigned bw = 0;
    if (type.isIntOrFloat())
      bw = type.getIntOrFloatBitWidth();
    else if (auto vecType = dyn_cast<VectorType>(type))
      bw = vecType.getElementTypeBitWidth() * vecType.getNumElements();
    return bw;
  };
  unsigned aBW = getNumBitwidth(a);
  unsigned bBW = getNumBitwidth(b);
  return aBW != 0 && bBW != 0 && aBW == bBW;
}
 
/// Returns a source type conversion failure for `srcType` and operation `op`.
static LogicalResult
getTypeConversionFailure(ConversionPatternRewriter &rewriter, Operation *op,
                         Type srcType) {
  return rewriter.notifyMatchFailure(
      op->getLoc(),
      llvm::formatv("failed to convert source type '{0}'", srcType));
}
 
/// Returns a source type conversion failure for the result type of `op`.
static LogicalResult
getTypeConversionFailure(ConversionPatternRewriter &rewriter, Operation *op) {
  assert(op->getNumResults() == 1);
  return getTypeConversionFailure(rewriter, op, op->getResultTypes().front());
}
 
// TODO: Move to some common place?
static std::string getDecorationString(spirv::Decoration decor) {
  return llvm::convertToSnakeFromCamelCase(stringifyDecoration(decor));
}
 
namespace {
 
/// Converts elementwise unary, binary and ternary arith operations to SPIR-V
/// operations. Op can potentially support overflow flags.
template <typename Op, typename SPIRVOp>
struct ElementwiseArithOpPattern final : OpConversionPattern<Op> {
  using OpConversionPattern<Op>::OpConversionPattern;
 
  LogicalResult
  matchAndRewrite(Op op, typename Op::Adaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    assert(adaptor.getOperands().size() <= 3);
    auto converter = this->template getTypeConverter<SPIRVTypeConverter>();
    Type dstType = converter->convertType(op.getType());
    if (!dstType) {
      return rewriter.notifyMatchFailure(
          op->getLoc(),
          llvm::formatv("failed to convert type {0} for SPIR-V", op.getType()));
    }
 
    if (SPIRVOp::template hasTrait<OpTrait::spirv::UnsignedOp>() &&
        !getElementTypeOrSelf(op.getType()).isIndex() &&
        dstType != op.getType()) {
      return op.emitError("bitwidth emulation is not implemented yet on "
                          "unsigned op pattern version");
    }
 
    auto overflowFlags = arith::IntegerOverflowFlags::none;
    if (auto overflowIface =
            dyn_cast<arith::ArithIntegerOverflowFlagsInterface>(*op)) {
      if (converter->getTargetEnv().allows(
              spirv::Extension::SPV_KHR_no_integer_wrap_decoration))
        overflowFlags = overflowIface.getOverflowAttr().getValue();
    }
 
    auto newOp = rewriter.template replaceOpWithNewOp<SPIRVOp>(
        op, dstType, adaptor.getOperands());
 
    if (bitEnumContainsAny(overflowFlags, arith::IntegerOverflowFlags::nsw))
      newOp->setAttr(getDecorationString(spirv::Decoration::NoSignedWrap),
                     rewriter.getUnitAttr());
 
    if (bitEnumContainsAny(overflowFlags, arith::IntegerOverflowFlags::nuw))
      newOp->setAttr(getDecorationString(spirv::Decoration::NoUnsignedWrap),
                     rewriter.getUnitAttr());
 
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// ConstantOp
//===----------------------------------------------------------------------===//
 
/// Converts composite arith.constant operation to spirv.Constant.
struct ConstantCompositeOpPattern final
    : public OpConversionPattern<arith::ConstantOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::ConstantOp constOp, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    auto srcType = dyn_cast<ShapedType>(constOp.getType());
    if (!srcType || srcType.getNumElements() == 1)
      return failure();
 
    // arith.constant should only have vector or tensor types. This is a MLIR
    // wide problem at the moment.
    if (!isa<VectorType, RankedTensorType>(srcType))
      return rewriter.notifyMatchFailure(constOp, "unsupported ShapedType");
 
    Type dstType = getTypeConverter()->convertType(srcType);
    if (!dstType)
      return failure();
 
    // Import the resource into the IR to make use of the special handling of
    // element types later on.
    mlir::DenseElementsAttr dstElementsAttr;
    if (auto denseElementsAttr =
            dyn_cast<DenseElementsAttr>(constOp.getValue())) {
      dstElementsAttr = denseElementsAttr;
    } else if (auto resourceAttr =
                   dyn_cast<DenseResourceElementsAttr>(constOp.getValue())) {
 
      AsmResourceBlob *blob = resourceAttr.getRawHandle().getBlob();
      if (!blob)
        return constOp->emitError("could not find resource blob");
 
      ArrayRef<char> ptr = blob->getData();
 
      // Check that the buffer meets the requirements to get converted to a
      // DenseElementsAttr
      bool detectedSplat = false;
      if (!DenseElementsAttr::isValidRawBuffer(srcType, ptr, detectedSplat))
        return constOp->emitError("resource is not a valid buffer");
 
      dstElementsAttr =
          DenseElementsAttr::getFromRawBuffer(resourceAttr.getType(), ptr);
    } else {
      return constOp->emitError("unsupported elements attribute");
    }
 
    ShapedType dstAttrType = dstElementsAttr.getType();
 
    // If the composite type has more than one dimensions, perform
    // linearization.
    if (srcType.getRank() > 1) {
      if (isa<RankedTensorType>(srcType)) {
        dstAttrType = RankedTensorType::get(srcType.getNumElements(),
                                            srcType.getElementType());
        dstElementsAttr = dstElementsAttr.reshape(dstAttrType);
      } else {
        // TODO: add support for large vectors.
        return failure();
      }
    }
 
    Type srcElemType = srcType.getElementType();
    Type dstElemType;
    // Tensor types are converted to SPIR-V array types; vector types are
    // converted to SPIR-V vector/array types.
    if (auto arrayType = dyn_cast<spirv::ArrayType>(dstType))
      dstElemType = arrayType.getElementType();
    else
      dstElemType = cast<VectorType>(dstType).getElementType();
 
    // If the source and destination element types are different, perform
    // attribute conversion.
    if (srcElemType != dstElemType) {
      SmallVector<Attribute, 8> elements;
      if (isa<FloatType>(srcElemType)) {
        for (FloatAttr srcAttr : dstElementsAttr.getValues<FloatAttr>()) {
          Attribute dstAttr = nullptr;
          // Handle 8-bit float conversion to 8-bit integer.
          auto *typeConverter = getTypeConverter<SPIRVTypeConverter>();
          if (typeConverter->getOptions().emulateUnsupportedFloatTypes &&
              srcElemType.getIntOrFloatBitWidth() == 8 &&
              isa<IntegerType>(dstElemType)) {
            dstAttr =
                getIntegerAttrFromFloatAttr(srcAttr, dstElemType, rewriter);
          } else {
            dstAttr = convertFloatAttr(srcAttr, cast<FloatType>(dstElemType),
                                       rewriter);
          }
          if (!dstAttr)
            return failure();
          elements.push_back(dstAttr);
        }
      } else if (srcElemType.isInteger(1)) {
        return failure();
      } else {
        for (IntegerAttr srcAttr : dstElementsAttr.getValues<IntegerAttr>()) {
          IntegerAttr dstAttr = convertIntegerAttr(
              srcAttr, cast<IntegerType>(dstElemType), rewriter);
          if (!dstAttr)
            return failure();
          elements.push_back(dstAttr);
        }
      }
 
      // Unfortunately, we cannot use dialect-specific types for element
      // attributes; element attributes only works with builtin types. So we
      // need to prepare another converted builtin types for the destination
      // elements attribute.
      if (isa<RankedTensorType>(dstAttrType))
        dstAttrType =
            RankedTensorType::get(dstAttrType.getShape(), dstElemType);
      else
        dstAttrType = VectorType::get(dstAttrType.getShape(), dstElemType);
 
      dstElementsAttr = DenseElementsAttr::get(dstAttrType, elements);
    }
 
    rewriter.replaceOpWithNewOp<spirv::ConstantOp>(constOp, dstType,
                                                   dstElementsAttr);
    return success();
  }
};
 
/// Converts scalar arith.constant operation to spirv.Constant.
struct ConstantScalarOpPattern final
    : public OpConversionPattern<arith::ConstantOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::ConstantOp constOp, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = constOp.getType();
    if (auto shapedType = dyn_cast<ShapedType>(srcType)) {
      if (shapedType.getNumElements() != 1)
        return failure();
      srcType = shapedType.getElementType();
    }
    if (!srcType.isIntOrIndexOrFloat())
      return failure();
 
    Attribute cstAttr = constOp.getValue();
    if (auto elementsAttr = dyn_cast<DenseElementsAttr>(cstAttr))
      cstAttr = elementsAttr.getSplatValue<Attribute>();
 
    Type dstType = getTypeConverter()->convertType(srcType);
    if (!dstType)
      return failure();
 
    // Floating-point types.
    if (isa<FloatType>(srcType)) {
      auto srcAttr = cast<FloatAttr>(cstAttr);
      Attribute dstAttr = srcAttr;
 
      // Floating-point types not supported in the target environment are all
      // converted to float type.
      auto *typeConverter = getTypeConverter<SPIRVTypeConverter>();
      if (typeConverter->getOptions().emulateUnsupportedFloatTypes &&
          srcType.getIntOrFloatBitWidth() == 8 && isa<IntegerType>(dstType) &&
          dstType.getIntOrFloatBitWidth() == 8) {
        // If the source is an 8-bit float, convert it to a 8-bit integer.
        dstAttr = getIntegerAttrFromFloatAttr(srcAttr, dstType, rewriter);
        if (!dstAttr)
          return failure();
      } else if (srcType != dstType) {
        dstAttr = convertFloatAttr(srcAttr, cast<FloatType>(dstType), rewriter);
        if (!dstAttr)
          return failure();
      }
 
      rewriter.replaceOpWithNewOp<spirv::ConstantOp>(constOp, dstType, dstAttr);
      return success();
    }
 
    // Bool type.
    if (srcType.isInteger(1)) {
      // arith.constant can use 0/1 instead of true/false for i1 values. We need
      // to handle that here.
      auto dstAttr = convertBoolAttr(cstAttr, rewriter);
      if (!dstAttr)
        return failure();
      rewriter.replaceOpWithNewOp<spirv::ConstantOp>(constOp, dstType, dstAttr);
      return success();
    }
 
    // IndexType or IntegerType. Index values are converted to 32-bit integer
    // values when converting to SPIR-V.
    auto srcAttr = cast<IntegerAttr>(cstAttr);
    IntegerAttr dstAttr =
        convertIntegerAttr(srcAttr, cast<IntegerType>(dstType), rewriter);
    if (!dstAttr)
      return failure();
    rewriter.replaceOpWithNewOp<spirv::ConstantOp>(constOp, dstType, dstAttr);
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// RemSIOp
//===----------------------------------------------------------------------===//
 
/// Returns signed remainder for `lhs` and `rhs` and lets the result follow
/// the sign of `signOperand`.
///
/// Note that this is needed for Vulkan. Per the Vulkan's SPIR-V environment
/// spec, "for the OpSRem and OpSMod instructions, if either operand is negative
/// the result is undefined."  So we cannot directly use spirv.SRem/spirv.SMod
/// if either operand can be negative. Emulate it via spirv.UMod.
template <typename SignedAbsOp>
static Value emulateSignedRemainder(Location loc, Value lhs, Value rhs,
                                    Value signOperand, OpBuilder &builder) {
  assert(lhs.getType() == rhs.getType());
  assert(lhs == signOperand || rhs == signOperand);
 
  Type type = lhs.getType();
 
  // Calculate the remainder with spirv.UMod.
  Value lhsAbs = SignedAbsOp::create(builder, loc, type, lhs);
  Value rhsAbs = SignedAbsOp::create(builder, loc, type, rhs);
  Value abs = spirv::UModOp::create(builder, loc, lhsAbs, rhsAbs);
 
  // Fix the sign.
  Value isPositive;
  if (lhs == signOperand)
    isPositive = spirv::IEqualOp::create(builder, loc, lhs, lhsAbs);
  else
    isPositive = spirv::IEqualOp::create(builder, loc, rhs, rhsAbs);
  Value absNegate = spirv::SNegateOp::create(builder, loc, type, abs);
  return spirv::SelectOp::create(builder, loc, type, isPositive, abs,
                                 absNegate);
}
 
/// Converts arith.remsi to GLSL SPIR-V ops.
///
/// This cannot be merged into the template unary/binary pattern due to Vulkan
/// restrictions over spirv.SRem and spirv.SMod.
struct RemSIOpGLPattern final : public OpConversionPattern<arith::RemSIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::RemSIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Value result = emulateSignedRemainder<spirv::CLSAbsOp>(
        op.getLoc(), adaptor.getOperands()[0], adaptor.getOperands()[1],
        adaptor.getOperands()[0], rewriter);
    rewriter.replaceOp(op, result);
 
    return success();
  }
};
 
/// Converts arith.remsi to OpenCL SPIR-V ops.
struct RemSIOpCLPattern final : public OpConversionPattern<arith::RemSIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::RemSIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Value result = emulateSignedRemainder<spirv::GLSAbsOp>(
        op.getLoc(), adaptor.getOperands()[0], adaptor.getOperands()[1],
        adaptor.getOperands()[0], rewriter);
    rewriter.replaceOp(op, result);
 
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// BitwiseOp
//===----------------------------------------------------------------------===//
 
/// Converts bitwise operations to SPIR-V operations. This is a special pattern
/// other than the BinaryOpPatternPattern because if the operands are boolean
/// values, SPIR-V uses different operations (`SPIRVLogicalOp`). For
/// non-boolean operands, SPIR-V should use `SPIRVBitwiseOp`.
template <typename Op, typename SPIRVLogicalOp, typename SPIRVBitwiseOp>
struct BitwiseOpPattern final : public OpConversionPattern<Op> {
  using OpConversionPattern<Op>::OpConversionPattern;
 
  LogicalResult
  matchAndRewrite(Op op, typename Op::Adaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    assert(adaptor.getOperands().size() == 2);
    Type dstType = this->getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    if (isBoolScalarOrVector(adaptor.getOperands().front().getType())) {
      rewriter.template replaceOpWithNewOp<SPIRVLogicalOp>(
          op, dstType, adaptor.getOperands());
    } else {
      rewriter.template replaceOpWithNewOp<SPIRVBitwiseOp>(
          op, dstType, adaptor.getOperands());
    }
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// XOrIOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.xori to SPIR-V operations.
struct XOrIOpLogicalPattern final : public OpConversionPattern<arith::XOrIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::XOrIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    assert(adaptor.getOperands().size() == 2);
 
    if (isBoolScalarOrVector(adaptor.getOperands().front().getType()))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    rewriter.replaceOpWithNewOp<spirv::BitwiseXorOp>(op, dstType,
                                                     adaptor.getOperands());
 
    return success();
  }
};
 
/// Converts arith.xori to SPIR-V operations if the type of source is i1 or
/// vector of i1.
struct XOrIOpBooleanPattern final : public OpConversionPattern<arith::XOrIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::XOrIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    assert(adaptor.getOperands().size() == 2);
 
    if (!isBoolScalarOrVector(adaptor.getOperands().front().getType()))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    rewriter.replaceOpWithNewOp<spirv::LogicalNotEqualOp>(
        op, dstType, adaptor.getOperands());
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// UIToFPOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.uitofp to spirv.Select if the type of source is i1 or vector
/// of i1.
struct UIToFPI1Pattern final : public OpConversionPattern<arith::UIToFPOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::UIToFPOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = adaptor.getOperands().front().getType();
    if (!isBoolScalarOrVector(srcType))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    Location loc = op.getLoc();
    Value zero = spirv::ConstantOp::getZero(dstType, loc, rewriter);
    Value one = spirv::ConstantOp::getOne(dstType, loc, rewriter);
    rewriter.replaceOpWithNewOp<spirv::SelectOp>(
        op, dstType, adaptor.getOperands().front(), one, zero);
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// IndexCastOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.index_cast to spirv.INotEqual if the target type is i1.
struct IndexCastIndexI1Pattern final
    : public OpConversionPattern<arith::IndexCastOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::IndexCastOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    if (!isBoolScalarOrVector(op.getType()))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    Location loc = op.getLoc();
    Value zeroIdx =
        spirv::ConstantOp::getZero(adaptor.getIn().getType(), loc, rewriter);
    rewriter.replaceOpWithNewOp<spirv::INotEqualOp>(op, dstType, zeroIdx,
                                                    adaptor.getIn());
    return success();
  }
};
 
/// Converts arith.index_cast to spirv.Select if the source type is i1.
struct IndexCastI1IndexPattern final
    : public OpConversionPattern<arith::IndexCastOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::IndexCastOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    if (!isBoolScalarOrVector(adaptor.getIn().getType()))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    Location loc = op.getLoc();
    Value zero = spirv::ConstantOp::getZero(dstType, loc, rewriter);
    Value one = spirv::ConstantOp::getOne(dstType, loc, rewriter);
    rewriter.replaceOpWithNewOp<spirv::SelectOp>(op, dstType, adaptor.getIn(),
                                                 one, zero);
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// ExtSIOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.extsi to spirv.Select if the type of source is i1 or vector
/// of i1.
struct ExtSII1Pattern final : public OpConversionPattern<arith::ExtSIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::ExtSIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Value operand = adaptor.getIn();
    if (!isBoolScalarOrVector(operand.getType()))
      return failure();
 
    Location loc = op.getLoc();
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    Value allOnes;
    if (auto intTy = dyn_cast<IntegerType>(dstType)) {
      unsigned componentBitwidth = intTy.getWidth();
      allOnes = spirv::ConstantOp::create(
          rewriter, loc, intTy,
          rewriter.getIntegerAttr(intTy, APInt::getAllOnes(componentBitwidth)));
    } else if (auto vectorTy = dyn_cast<VectorType>(dstType)) {
      unsigned componentBitwidth = vectorTy.getElementTypeBitWidth();
      allOnes = spirv::ConstantOp::create(
          rewriter, loc, vectorTy,
          SplatElementsAttr::get(vectorTy,
                                 APInt::getAllOnes(componentBitwidth)));
    } else {
      return rewriter.notifyMatchFailure(
          loc, llvm::formatv("unhandled type: {0}", dstType));
    }
 
    Value zero = spirv::ConstantOp::getZero(dstType, loc, rewriter);
    rewriter.replaceOpWithNewOp<spirv::SelectOp>(op, dstType, operand, allOnes,
                                                 zero);
    return success();
  }
};
 
/// Converts arith.extsi to spirv.Select if the type of source is neither i1 nor
/// vector of i1.
struct ExtSIPattern final : public OpConversionPattern<arith::ExtSIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::ExtSIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = adaptor.getIn().getType();
    if (isBoolScalarOrVector(srcType))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    if (dstType == srcType) {
      // We can have the same source and destination type due to type emulation.
      // Perform bit shifting to make sure we have the proper leading set bits.
 
      unsigned srcBW =
          getElementTypeOrSelf(op.getIn().getType()).getIntOrFloatBitWidth();
      unsigned dstBW =
          getElementTypeOrSelf(op.getType()).getIntOrFloatBitWidth();
      assert(srcBW < dstBW);
      Value shiftSize = getScalarOrVectorConstInt(dstType, dstBW - srcBW,
                                                  rewriter, op.getLoc());
 
      // First shift left to sequeeze out all leading bits beyond the original
      // bitwidth. Here we need to use the original source and result type's
      // bitwidth.
      auto shiftLOp = spirv::ShiftLeftLogicalOp::create(
          rewriter, op.getLoc(), dstType, adaptor.getIn(), shiftSize);
 
      // Then we perform arithmetic right shift to make sure we have the right
      // sign bits for negative values.
      rewriter.replaceOpWithNewOp<spirv::ShiftRightArithmeticOp>(
          op, dstType, shiftLOp, shiftSize);
    } else {
      rewriter.replaceOpWithNewOp<spirv::SConvertOp>(op, dstType,
                                                     adaptor.getOperands());
    }
 
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// ExtUIOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.extui to spirv.Select if the type of source is i1 or vector
/// of i1.
struct ExtUII1Pattern final : public OpConversionPattern<arith::ExtUIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::ExtUIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = adaptor.getOperands().front().getType();
    if (!isBoolScalarOrVector(srcType))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    Location loc = op.getLoc();
    Value zero = spirv::ConstantOp::getZero(dstType, loc, rewriter);
    Value one = spirv::ConstantOp::getOne(dstType, loc, rewriter);
    rewriter.replaceOpWithNewOp<spirv::SelectOp>(
        op, dstType, adaptor.getOperands().front(), one, zero);
    return success();
  }
};
 
/// Converts arith.extui for cases where the type of source is neither i1 nor
/// vector of i1.
struct ExtUIPattern final : public OpConversionPattern<arith::ExtUIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::ExtUIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = adaptor.getIn().getType();
    if (isBoolScalarOrVector(srcType))
      return failure();
 
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    if (dstType == srcType) {
      // We can have the same source and destination type due to type emulation.
      // Perform bit masking to make sure we don't pollute downstream consumers
      // with unwanted bits. Here we need to use the original source type's
      // bitwidth.
      unsigned bitwidth =
          getElementTypeOrSelf(op.getIn().getType()).getIntOrFloatBitWidth();
      Value mask = getScalarOrVectorConstInt(
          dstType, llvm::maskTrailingOnes<uint64_t>(bitwidth), rewriter,
          op.getLoc());
      rewriter.replaceOpWithNewOp<spirv::BitwiseAndOp>(op, dstType,
                                                       adaptor.getIn(), mask);
    } else {
      rewriter.replaceOpWithNewOp<spirv::UConvertOp>(op, dstType,
                                                     adaptor.getOperands());
    }
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// TruncIOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.trunci to spirv.Select if the type of result is i1 or vector
/// of i1.
struct TruncII1Pattern final : public OpConversionPattern<arith::TruncIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::TruncIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    if (!isBoolScalarOrVector(dstType))
      return failure();
 
    Location loc = op.getLoc();
    auto srcType = adaptor.getOperands().front().getType();
    // Check if (x & 1) == 1.
    Value mask = spirv::ConstantOp::getOne(srcType, loc, rewriter);
    Value maskedSrc = spirv::BitwiseAndOp::create(
        rewriter, loc, srcType, adaptor.getOperands()[0], mask);
    Value isOne = spirv::IEqualOp::create(rewriter, loc, maskedSrc, mask);
 
    Value zero = spirv::ConstantOp::getZero(dstType, loc, rewriter);
    Value one = spirv::ConstantOp::getOne(dstType, loc, rewriter);
    rewriter.replaceOpWithNewOp<spirv::SelectOp>(op, dstType, isOne, one, zero);
    return success();
  }
};
 
/// Converts arith.trunci for cases where the type of result is neither i1
/// nor vector of i1.
struct TruncIPattern final : public OpConversionPattern<arith::TruncIOp> {
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::TruncIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = adaptor.getIn().getType();
    Type dstType = getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    if (isBoolScalarOrVector(dstType))
      return failure();
 
    if (dstType == srcType) {
      // We can have the same source and destination type due to type emulation.
      // Perform bit masking to make sure we don't pollute downstream consumers
      // with unwanted bits. Here we need to use the original result type's
      // bitwidth.
      unsigned bw = getElementTypeOrSelf(op.getType()).getIntOrFloatBitWidth();
      Value mask = getScalarOrVectorConstInt(
          dstType, llvm::maskTrailingOnes<uint64_t>(bw), rewriter, op.getLoc());
      rewriter.replaceOpWithNewOp<spirv::BitwiseAndOp>(op, dstType,
                                                       adaptor.getIn(), mask);
    } else {
      // Given this is truncation, either SConvertOp or UConvertOp works.
      rewriter.replaceOpWithNewOp<spirv::SConvertOp>(op, dstType,
                                                     adaptor.getOperands());
    }
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// TypeCastingOp
//===----------------------------------------------------------------------===//
 
static std::optional<spirv::FPRoundingMode>
convertArithRoundingModeToSPIRV(arith::RoundingMode roundingMode) {
  switch (roundingMode) {
  case arith::RoundingMode::downward:
    return spirv::FPRoundingMode::RTN;
  case arith::RoundingMode::to_nearest_even:
    return spirv::FPRoundingMode::RTE;
  case arith::RoundingMode::toward_zero:
    return spirv::FPRoundingMode::RTZ;
  case arith::RoundingMode::upward:
    return spirv::FPRoundingMode::RTP;
  case arith::RoundingMode::to_nearest_away:
    // SPIR-V FPRoundingMode decoration has no ties-away-from-zero mode
    // (as of SPIR-V 1.6)
    return std::nullopt;
  }
  llvm_unreachable("Unhandled rounding mode");
}
 
/// Converts type-casting standard operations to SPIR-V operations.
template <typename Op, typename SPIRVOp>
struct TypeCastingOpPattern final : public OpConversionPattern<Op> {
  using OpConversionPattern<Op>::OpConversionPattern;
 
  LogicalResult
  matchAndRewrite(Op op, typename Op::Adaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = llvm::getSingleElement(adaptor.getOperands()).getType();
    Type dstType = this->getTypeConverter()->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    if (isBoolScalarOrVector(srcType) || isBoolScalarOrVector(dstType))
      return failure();
 
    if (dstType == srcType) {
      // Due to type conversion, we are seeing the same source and target type.
      // Then we can just erase this operation by forwarding its operand.
      rewriter.replaceOp(op, adaptor.getOperands().front());
    } else {
      // Compute new rounding mode (if any).
      std::optional<spirv::FPRoundingMode> rm = std::nullopt;
      if (auto roundingModeOp =
              dyn_cast<arith::ArithRoundingModeInterface>(*op)) {
        if (arith::RoundingModeAttr roundingMode =
                roundingModeOp.getRoundingModeAttr()) {
          if (!(rm =
                    convertArithRoundingModeToSPIRV(roundingMode.getValue()))) {
            return rewriter.notifyMatchFailure(
                op->getLoc(),
                llvm::formatv("unsupported rounding mode '{0}'", roundingMode));
          }
        }
      }
      // Create replacement op and attach rounding mode attribute (if any).
      auto newOp = rewriter.template replaceOpWithNewOp<SPIRVOp>(
          op, dstType, adaptor.getOperands());
      if (rm) {
        newOp->setAttr(
            getDecorationString(spirv::Decoration::FPRoundingMode),
            spirv::FPRoundingModeAttr::get(rewriter.getContext(), *rm));
      }
    }
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// CmpIOp
//===----------------------------------------------------------------------===//
 
/// Converts integer compare operation on i1 type operands to SPIR-V ops.
class CmpIOpBooleanPattern final : public OpConversionPattern<arith::CmpIOp> {
public:
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::CmpIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = op.getLhs().getType();
    if (!isBoolScalarOrVector(srcType))
      return failure();
    Type dstType = getTypeConverter()->convertType(srcType);
    if (!dstType)
      return getTypeConversionFailure(rewriter, op, srcType);
 
    switch (op.getPredicate()) {
    case arith::CmpIPredicate::eq: {
      rewriter.replaceOpWithNewOp<spirv::LogicalEqualOp>(op, adaptor.getLhs(),
                                                         adaptor.getRhs());
      return success();
    }
    case arith::CmpIPredicate::ne: {
      rewriter.replaceOpWithNewOp<spirv::LogicalNotEqualOp>(
          op, adaptor.getLhs(), adaptor.getRhs());
      return success();
    }
    case arith::CmpIPredicate::uge:
    case arith::CmpIPredicate::ugt:
    case arith::CmpIPredicate::ule:
    case arith::CmpIPredicate::ult: {
      // There are no direct corresponding instructions in SPIR-V for such
      // cases. Extend them to 32-bit and do comparision then.
      Type type = rewriter.getI32Type();
      if (auto vectorType = dyn_cast<VectorType>(dstType))
        type = VectorType::get(vectorType.getShape(), type);
      Value extLhs =
          arith::ExtUIOp::create(rewriter, op.getLoc(), type, adaptor.getLhs());
      Value extRhs =
          arith::ExtUIOp::create(rewriter, op.getLoc(), type, adaptor.getRhs());
 
      rewriter.replaceOpWithNewOp<arith::CmpIOp>(op, op.getPredicate(), extLhs,
                                                 extRhs);
      return success();
    }
    default:
      break;
    }
    return failure();
  }
};
 
/// Converts integer compare operation to SPIR-V ops.
class CmpIOpPattern final : public OpConversionPattern<arith::CmpIOp> {
public:
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::CmpIOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type srcType = op.getLhs().getType();
    if (isBoolScalarOrVector(srcType))
      return failure();
    Type dstType = getTypeConverter()->convertType(srcType);
    if (!dstType)
      return getTypeConversionFailure(rewriter, op, srcType);
 
    switch (op.getPredicate()) {
#define DISPATCH(cmpPredicate, spirvOp)                                        \
  case cmpPredicate:                                                           \
    if (spirvOp::template hasTrait<OpTrait::spirv::UnsignedOp>() &&            \
        !getElementTypeOrSelf(srcType).isIndex() && srcType != dstType &&      \
        !hasSameBitwidth(srcType, dstType)) {                                  \
      return op.emitError(                                                     \
          "bitwidth emulation is not implemented yet on unsigned op");         \
    }                                                                          \
    rewriter.replaceOpWithNewOp<spirvOp>(op, adaptor.getLhs(),                 \
                                         adaptor.getRhs());                    \
    return success();
 
      DISPATCH(arith::CmpIPredicate::eq, spirv::IEqualOp);
      DISPATCH(arith::CmpIPredicate::ne, spirv::INotEqualOp);
      DISPATCH(arith::CmpIPredicate::slt, spirv::SLessThanOp);
      DISPATCH(arith::CmpIPredicate::sle, spirv::SLessThanEqualOp);
      DISPATCH(arith::CmpIPredicate::sgt, spirv::SGreaterThanOp);
      DISPATCH(arith::CmpIPredicate::sge, spirv::SGreaterThanEqualOp);
      DISPATCH(arith::CmpIPredicate::ult, spirv::ULessThanOp);
      DISPATCH(arith::CmpIPredicate::ule, spirv::ULessThanEqualOp);
      DISPATCH(arith::CmpIPredicate::ugt, spirv::UGreaterThanOp);
      DISPATCH(arith::CmpIPredicate::uge, spirv::UGreaterThanEqualOp);
 
#undef DISPATCH
    }
    return failure();
  }
};
 
//===----------------------------------------------------------------------===//
// CmpFOpPattern
//===----------------------------------------------------------------------===//
 
/// Converts floating-point comparison operations to SPIR-V ops.
class CmpFOpPattern final : public OpConversionPattern<arith::CmpFOp> {
public:
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::CmpFOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    switch (op.getPredicate()) {
#define DISPATCH(cmpPredicate, spirvOp)                                        \
  case cmpPredicate:                                                           \
    rewriter.replaceOpWithNewOp<spirvOp>(op, adaptor.getLhs(),                 \
                                         adaptor.getRhs());                    \
    return success();
 
      // Ordered.
      DISPATCH(arith::CmpFPredicate::OEQ, spirv::FOrdEqualOp);
      DISPATCH(arith::CmpFPredicate::OGT, spirv::FOrdGreaterThanOp);
      DISPATCH(arith::CmpFPredicate::OGE, spirv::FOrdGreaterThanEqualOp);
      DISPATCH(arith::CmpFPredicate::OLT, spirv::FOrdLessThanOp);
      DISPATCH(arith::CmpFPredicate::OLE, spirv::FOrdLessThanEqualOp);
      DISPATCH(arith::CmpFPredicate::ONE, spirv::FOrdNotEqualOp);
      // Unordered.
      DISPATCH(arith::CmpFPredicate::UEQ, spirv::FUnordEqualOp);
      DISPATCH(arith::CmpFPredicate::UGT, spirv::FUnordGreaterThanOp);
      DISPATCH(arith::CmpFPredicate::UGE, spirv::FUnordGreaterThanEqualOp);
      DISPATCH(arith::CmpFPredicate::ULT, spirv::FUnordLessThanOp);
      DISPATCH(arith::CmpFPredicate::ULE, spirv::FUnordLessThanEqualOp);
      DISPATCH(arith::CmpFPredicate::UNE, spirv::FUnordNotEqualOp);
 
#undef DISPATCH
 
    default:
      break;
    }
    return failure();
  }
};
 
/// Converts floating point NaN check to SPIR-V ops. This pattern requires
/// Kernel capability.
class CmpFOpNanKernelPattern final : public OpConversionPattern<arith::CmpFOp> {
public:
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::CmpFOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    if (op.getPredicate() == arith::CmpFPredicate::ORD) {
      rewriter.replaceOpWithNewOp<spirv::OrderedOp>(op, adaptor.getLhs(),
                                                    adaptor.getRhs());
      return success();
    }
 
    if (op.getPredicate() == arith::CmpFPredicate::UNO) {
      rewriter.replaceOpWithNewOp<spirv::UnorderedOp>(op, adaptor.getLhs(),
                                                      adaptor.getRhs());
      return success();
    }
 
    return failure();
  }
};
 
/// Converts floating point NaN check to SPIR-V ops. This pattern does not
/// require additional capability.
class CmpFOpNanNonePattern final : public OpConversionPattern<arith::CmpFOp> {
public:
  using Base::Base;
 
  LogicalResult
  matchAndRewrite(arith::CmpFOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    if (op.getPredicate() != arith::CmpFPredicate::ORD &&
        op.getPredicate() != arith::CmpFPredicate::UNO)
      return failure();
 
    Location loc = op.getLoc();
 
    Value replace;
    if (bitEnumContainsAll(op.getFastmath(), arith::FastMathFlags::nnan)) {
      if (op.getPredicate() == arith::CmpFPredicate::ORD) {
        // Ordered comparsion checks if neither operand is NaN.
        replace = spirv::ConstantOp::getOne(op.getType(), loc, rewriter);
      } else {
        // Unordered comparsion checks if either operand is NaN.
        replace = spirv::ConstantOp::getZero(op.getType(), loc, rewriter);
      }
    } else {
      Value lhsIsNan = spirv::IsNanOp::create(rewriter, loc, adaptor.getLhs());
      Value rhsIsNan = spirv::IsNanOp::create(rewriter, loc, adaptor.getRhs());
 
      replace = spirv::LogicalOrOp::create(rewriter, loc, lhsIsNan, rhsIsNan);
      if (op.getPredicate() == arith::CmpFPredicate::ORD)
        replace = spirv::LogicalNotOp::create(rewriter, loc, replace);
    }
 
    rewriter.replaceOp(op, replace);
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// AddUIExtendedOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.addui_extended to spirv.IAddCarry.
class AddUIExtendedOpPattern final
    : public OpConversionPattern<arith::AddUIExtendedOp> {
public:
  using Base::Base;
  LogicalResult
  matchAndRewrite(arith::AddUIExtendedOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Type dstElemTy = adaptor.getLhs().getType();
    Location loc = op->getLoc();
    Value result = spirv::IAddCarryOp::create(rewriter, loc, adaptor.getLhs(),
                                              adaptor.getRhs());
 
    Value sumResult = spirv::CompositeExtractOp::create(rewriter, loc, result,
                                                        llvm::ArrayRef(0));
    Value carryValue = spirv::CompositeExtractOp::create(rewriter, loc, result,
                                                         llvm::ArrayRef(1));
 
    // Convert the carry value to boolean.
    Value one = spirv::ConstantOp::getOne(dstElemTy, loc, rewriter);
    Value carryResult = spirv::IEqualOp::create(rewriter, loc, carryValue, one);
 
    rewriter.replaceOp(op, {sumResult, carryResult});
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// MulIExtendedOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.mul*i_extended to spirv.*MulExtended.
template <typename ArithMulOp, typename SPIRVMulOp>
class MulIExtendedOpPattern final : public OpConversionPattern<ArithMulOp> {
public:
  using OpConversionPattern<ArithMulOp>::OpConversionPattern;
  LogicalResult
  matchAndRewrite(ArithMulOp op, typename ArithMulOp::Adaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Location loc = op->getLoc();
    Value result =
        SPIRVMulOp::create(rewriter, loc, adaptor.getLhs(), adaptor.getRhs());
 
    Value low = spirv::CompositeExtractOp::create(rewriter, loc, result,
                                                  llvm::ArrayRef(0));
    Value high = spirv::CompositeExtractOp::create(rewriter, loc, result,
                                                   llvm::ArrayRef(1));
 
    rewriter.replaceOp(op, {low, high});
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// SelectOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.select to spirv.Select.
class SelectOpPattern final : public OpConversionPattern<arith::SelectOp> {
public:
  using Base::Base;
  LogicalResult
  matchAndRewrite(arith::SelectOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    rewriter.replaceOpWithNewOp<spirv::SelectOp>(op, adaptor.getCondition(),
                                                 adaptor.getTrueValue(),
                                                 adaptor.getFalseValue());
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// MinimumFOp, MaximumFOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.maximumf/minimumf to spirv.GL.FMax/FMin or
/// spirv.CL.fmax/fmin.
template <typename Op, typename SPIRVOp>
class MinimumMaximumFOpPattern final : public OpConversionPattern<Op> {
public:
  using OpConversionPattern<Op>::OpConversionPattern;
  LogicalResult
  matchAndRewrite(Op op, typename Op::Adaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    auto *converter = this->template getTypeConverter<SPIRVTypeConverter>();
    Type dstType = converter->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    // arith.maximumf/minimumf:
    //   "if one of the arguments is NaN, then the result is also NaN."
    // spirv.GL.FMax/FMin
    //   "which operand is the result is undefined if one of the operands
    //   is a NaN."
    // spirv.CL.fmax/fmin:
    //   "If one argument is a NaN, Fmin returns the other argument."
 
    Location loc = op.getLoc();
    Value spirvOp =
        SPIRVOp::create(rewriter, loc, dstType, adaptor.getOperands());
 
    if (bitEnumContainsAll(op.getFastmath(), arith::FastMathFlags::nnan)) {
      rewriter.replaceOp(op, spirvOp);
      return success();
    }
 
    Value lhsIsNan = spirv::IsNanOp::create(rewriter, loc, adaptor.getLhs());
    Value rhsIsNan = spirv::IsNanOp::create(rewriter, loc, adaptor.getRhs());
 
    Value select1 = spirv::SelectOp::create(rewriter, loc, dstType, lhsIsNan,
                                            adaptor.getLhs(), spirvOp);
    Value select2 = spirv::SelectOp::create(rewriter, loc, dstType, rhsIsNan,
                                            adaptor.getRhs(), select1);
 
    rewriter.replaceOp(op, select2);
    return success();
  }
};
 
//===----------------------------------------------------------------------===//
// MinNumFOp, MaxNumFOp
//===----------------------------------------------------------------------===//
 
/// Converts arith.maxnumf/minnumf to spirv.GL.FMax/FMin or
/// spirv.CL.fmax/fmin.
template <typename Op, typename SPIRVOp>
class MinNumMaxNumFOpPattern final : public OpConversionPattern<Op> {
  template <typename TargetOp>
  constexpr bool shouldInsertNanGuards() const {
    return llvm::is_one_of<TargetOp, spirv::GLFMaxOp, spirv::GLFMinOp>::value;
  }
 
public:
  using OpConversionPattern<Op>::OpConversionPattern;
  LogicalResult
  matchAndRewrite(Op op, typename Op::Adaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    auto *converter = this->template getTypeConverter<SPIRVTypeConverter>();
    Type dstType = converter->convertType(op.getType());
    if (!dstType)
      return getTypeConversionFailure(rewriter, op);
 
    // arith.maxnumf/minnumf:
    //   "If one of the arguments is NaN, then the result is the other
    //   argument."
    // spirv.GL.FMax/FMin
    //   "which operand is the result is undefined if one of the operands
    //   is a NaN."
    // spirv.CL.fmax/fmin:
    //   "If one argument is a NaN, Fmin returns the other argument."
 
    Location loc = op.getLoc();
    Value spirvOp =
        SPIRVOp::create(rewriter, loc, dstType, adaptor.getOperands());
 
    if (!shouldInsertNanGuards<SPIRVOp>() ||
        bitEnumContainsAll(op.getFastmath(), arith::FastMathFlags::nnan)) {
      rewriter.replaceOp(op, spirvOp);
      return success();
    }
 
    Value lhsIsNan = spirv::IsNanOp::create(rewriter, loc, adaptor.getLhs());
    Value rhsIsNan = spirv::IsNanOp::create(rewriter, loc, adaptor.getRhs());
 
    Value select1 = spirv::SelectOp::create(rewriter, loc, dstType, lhsIsNan,
                                            adaptor.getRhs(), spirvOp);
    Value select2 = spirv::SelectOp::create(rewriter, loc, dstType, rhsIsNan,
                                            adaptor.getLhs(), select1);
 
    rewriter.replaceOp(op, select2);
    return success();
  }
};
 
} // namespace
 
//===----------------------------------------------------------------------===//
// Pattern Population
//===----------------------------------------------------------------------===//
 
void mlir::arith::populateArithToSPIRVPatterns(
    const SPIRVTypeConverter &typeConverter, RewritePatternSet &patterns) {
  // clang-format off
  patterns.add<
    ConstantCompositeOpPattern,
    ConstantScalarOpPattern,
    ElementwiseArithOpPattern<arith::AddIOp, spirv::IAddOp>,
    ElementwiseArithOpPattern<arith::SubIOp, spirv::ISubOp>,
    ElementwiseArithOpPattern<arith::MulIOp, spirv::IMulOp>,
    spirv::ElementwiseOpPattern<arith::DivUIOp, spirv::UDivOp>,
    spirv::ElementwiseOpPattern<arith::DivSIOp, spirv::SDivOp>,
    spirv::ElementwiseOpPattern<arith::RemUIOp, spirv::UModOp>,
    RemSIOpGLPattern, RemSIOpCLPattern,
    BitwiseOpPattern<arith::AndIOp, spirv::LogicalAndOp, spirv::BitwiseAndOp>,
    BitwiseOpPattern<arith::OrIOp, spirv::LogicalOrOp, spirv::BitwiseOrOp>,
    XOrIOpLogicalPattern, XOrIOpBooleanPattern,
    ElementwiseArithOpPattern<arith::ShLIOp, spirv::ShiftLeftLogicalOp>,
    spirv::ElementwiseOpPattern<arith::ShRUIOp, spirv::ShiftRightLogicalOp>,
    spirv::ElementwiseOpPattern<arith::ShRSIOp, spirv::ShiftRightArithmeticOp>,
    spirv::ElementwiseOpPattern<arith::NegFOp, spirv::FNegateOp>,
    spirv::ElementwiseOpPattern<arith::AddFOp, spirv::FAddOp>,
    spirv::ElementwiseOpPattern<arith::SubFOp, spirv::FSubOp>,
    spirv::ElementwiseOpPattern<arith::MulFOp, spirv::FMulOp>,
    spirv::ElementwiseOpPattern<arith::DivFOp, spirv::FDivOp>,
    spirv::ElementwiseOpPattern<arith::RemFOp, spirv::FRemOp>,
    ExtUIPattern, ExtUII1Pattern,
    ExtSIPattern, ExtSII1Pattern,
    TypeCastingOpPattern<arith::ExtFOp, spirv::FConvertOp>,
    TruncIPattern, TruncII1Pattern,
    TypeCastingOpPattern<arith::TruncFOp, spirv::FConvertOp>,
    TypeCastingOpPattern<arith::UIToFPOp, spirv::ConvertUToFOp>, UIToFPI1Pattern,
    TypeCastingOpPattern<arith::SIToFPOp, spirv::ConvertSToFOp>,
    TypeCastingOpPattern<arith::FPToUIOp, spirv::ConvertFToUOp>,
    TypeCastingOpPattern<arith::FPToSIOp, spirv::ConvertFToSOp>,
    TypeCastingOpPattern<arith::IndexCastOp, spirv::SConvertOp>,
    IndexCastIndexI1Pattern, IndexCastI1IndexPattern,
    TypeCastingOpPattern<arith::IndexCastUIOp, spirv::UConvertOp>,
    TypeCastingOpPattern<arith::BitcastOp, spirv::BitcastOp>,
    CmpIOpBooleanPattern, CmpIOpPattern,
    CmpFOpNanNonePattern, CmpFOpPattern,
    AddUIExtendedOpPattern,
    MulIExtendedOpPattern<arith::MulSIExtendedOp, spirv::SMulExtendedOp>,
    MulIExtendedOpPattern<arith::MulUIExtendedOp, spirv::UMulExtendedOp>,
    SelectOpPattern,
 
    MinimumMaximumFOpPattern<arith::MaximumFOp, spirv::GLFMaxOp>,
    MinimumMaximumFOpPattern<arith::MinimumFOp, spirv::GLFMinOp>,
    MinNumMaxNumFOpPattern<arith::MaxNumFOp, spirv::GLFMaxOp>,
    MinNumMaxNumFOpPattern<arith::MinNumFOp, spirv::GLFMinOp>,
    spirv::ElementwiseOpPattern<arith::MaxSIOp, spirv::GLSMaxOp>,
    spirv::ElementwiseOpPattern<arith::MaxUIOp, spirv::GLUMaxOp>,
    spirv::ElementwiseOpPattern<arith::MinSIOp, spirv::GLSMinOp>,
    spirv::ElementwiseOpPattern<arith::MinUIOp, spirv::GLUMinOp>,
 
    MinimumMaximumFOpPattern<arith::MaximumFOp, spirv::CLFMaxOp>,
    MinimumMaximumFOpPattern<arith::MinimumFOp, spirv::CLFMinOp>,
    MinNumMaxNumFOpPattern<arith::MaxNumFOp, spirv::CLFMaxOp>,
    MinNumMaxNumFOpPattern<arith::MinNumFOp, spirv::CLFMinOp>,
    spirv::ElementwiseOpPattern<arith::MaxSIOp, spirv::CLSMaxOp>,
    spirv::ElementwiseOpPattern<arith::MaxUIOp, spirv::CLUMaxOp>,
    spirv::ElementwiseOpPattern<arith::MinSIOp, spirv::CLSMinOp>,
    spirv::ElementwiseOpPattern<arith::MinUIOp, spirv::CLUMinOp>
  >(typeConverter, patterns.getContext());
  // clang-format on
 
  // Give CmpFOpNanKernelPattern a higher benefit so it can prevail when Kernel
  // capability is available.
  patterns.add<CmpFOpNanKernelPattern>(typeConverter, patterns.getContext(),
                                       /*benefit=*/2);
}
 
//===----------------------------------------------------------------------===//
// Pass Definition
//===----------------------------------------------------------------------===//
 
namespace {
struct ConvertArithToSPIRVPass
    : public impl::ConvertArithToSPIRVPassBase<ConvertArithToSPIRVPass> {
  using Base::Base;
 
  void runOnOperation() override {
    Operation *op = getOperation();
    spirv::TargetEnvAttr targetAttr = spirv::lookupTargetEnvOrDefault(op);
    std::unique_ptr<SPIRVConversionTarget> target =
        SPIRVConversionTarget::get(targetAttr);
 
    SPIRVConversionOptions options;
    options.emulateLT32BitScalarTypes = this->emulateLT32BitScalarTypes;
    options.emulateUnsupportedFloatTypes = this->emulateUnsupportedFloatTypes;
    SPIRVTypeConverter typeConverter(targetAttr, options);
 
    // Use UnrealizedConversionCast as the bridge so that we don't need to pull
    // in patterns for other dialects.
    target->addLegalOp<UnrealizedConversionCastOp>();
 
    // Fail hard when there are any remaining 'arith' ops.
    target->addIllegalDialect<arith::ArithDialect>();
 
    RewritePatternSet patterns(&getContext());
    arith::populateArithToSPIRVPatterns(typeConverter, patterns);
 
    if (failed(applyPartialConversion(op, *target, std::move(patterns))))
      signalPassFailure();
  }
};
} // namespace