source/opt/inst_bindless_check_pass.cpp

// Copyright (c) 2018 The Khronos Group Inc.
// Copyright (c) 2018 Valve Corporation
// Copyright (c) 2018 LunarG Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "inst_bindless_check_pass.h"

#include "source/spirv_constant.h"

namespace spvtools {
namespace opt {
namespace {
// Input Operand Indices
constexpr int kSpvImageSampleImageIdInIdx = 0;
constexpr int kSpvSampledImageImageIdInIdx = 0;
constexpr int kSpvSampledImageSamplerIdInIdx = 1;
constexpr int kSpvImageSampledImageIdInIdx = 0;
constexpr int kSpvCopyObjectOperandIdInIdx = 0;
constexpr int kSpvLoadPtrIdInIdx = 0;
constexpr int kSpvAccessChainBaseIdInIdx = 0;
constexpr int kSpvAccessChainIndex0IdInIdx = 1;
constexpr int kSpvTypeArrayTypeIdInIdx = 0;
constexpr int kSpvVariableStorageClassInIdx = 0;
constexpr int kSpvTypePtrTypeIdInIdx = 1;
constexpr int kSpvTypeImageDim = 1;
constexpr int kSpvTypeImageDepth = 2;
constexpr int kSpvTypeImageArrayed = 3;
constexpr int kSpvTypeImageMS = 4;
}  // namespace

// This is a stub function for use with Import linkage
// clang-format off
// GLSL:
//bool inst_bindless_check_desc(const uint shader_id, const uint inst_num, const uvec4 stage_info, const uint desc_set,
//                              const uint binding, const uint desc_index, const uint byte_offset) {
//}
// clang-format on
uint32_t InstBindlessCheckPass::GenDescCheckFunctionId() {
  enum {
    kShaderId = 0,
    kInstructionIndex = 1,
    kStageInfo = 2,
    kDescSet = 3,
    kDescBinding = 4,
    kDescIndex = 5,
    kByteOffset = 6,
    kNumArgs
  };
  if (check_desc_func_id_ != 0) {
    return check_desc_func_id_;
  }

  analysis::TypeManager* type_mgr = context()->get_type_mgr();
  const analysis::Integer* uint_type = GetInteger(32, false);
  const analysis::Vector v4uint(uint_type, 4);
  const analysis::Type* v4uint_type = type_mgr->GetRegisteredType(&v4uint);
  std::vector<const analysis::Type*> param_types(kNumArgs, uint_type);
  param_types[2] = v4uint_type;

  const uint32_t func_id = TakeNextId();
  std::unique_ptr<Function> func =
      StartFunction(func_id, type_mgr->GetBoolType(), param_types);

  func->SetFunctionEnd(EndFunction());

  static const std::string func_name{"inst_bindless_check_desc"};
  context()->AddFunctionDeclaration(std::move(func));
  context()->AddDebug2Inst(NewName(func_id, func_name));
  std::vector<Operand> operands{
      {spv_operand_type_t::SPV_OPERAND_TYPE_ID, {func_id}},
      {spv_operand_type_t::SPV_OPERAND_TYPE_LITERAL_INTEGER,
       {uint32_t(spv::Decoration::LinkageAttributes)}},
      {spv_operand_type_t::SPV_OPERAND_TYPE_LITERAL_STRING,
       utils::MakeVector(func_name.c_str())},
      {spv_operand_type_t::SPV_OPERAND_TYPE_LINKAGE_TYPE,
       {uint32_t(spv::LinkageType::Import)}},
  };
  get_decoration_mgr()->AddDecoration(spv::Op::OpDecorate, operands);

  check_desc_func_id_ = func_id;
  // Make sure function doesn't get processed by
  // InstrumentPass::InstProcessCallTreeFromRoots()
  param2output_func_id_[3] = func_id;
  return check_desc_func_id_;
}

// clang-format off
// GLSL:
// result = inst_bindless_check_desc(shader_id, inst_idx, stage_info, desc_set, binding, desc_idx, offset);
//
// clang-format on
uint32_t InstBindlessCheckPass::GenDescCheckCall(
    uint32_t inst_idx, uint32_t stage_idx, uint32_t var_id,
    uint32_t desc_idx_id, uint32_t offset_id, InstructionBuilder* builder) {
  const uint32_t func_id = GenDescCheckFunctionId();
  const std::vector<uint32_t> args = {
      builder->GetUintConstantId(shader_id_),
      builder->GetUintConstantId(inst_idx),
      GenStageInfo(stage_idx, builder),
      builder->GetUintConstantId(var2desc_set_[var_id]),
      builder->GetUintConstantId(var2binding_[var_id]),
      GenUintCastCode(desc_idx_id, builder),
      offset_id};
  return GenReadFunctionCall(GetBoolId(), func_id, args, builder);
}

uint32_t InstBindlessCheckPass::CloneOriginalImage(
    uint32_t old_image_id, InstructionBuilder* builder) {
  Instruction* new_image_inst;
  Instruction* old_image_inst = get_def_use_mgr()->GetDef(old_image_id);
  if (old_image_inst->opcode() == spv::Op::OpLoad) {
    new_image_inst = builder->AddLoad(
        old_image_inst->type_id(),
        old_image_inst->GetSingleWordInOperand(kSpvLoadPtrIdInIdx));
  } else if (old_image_inst->opcode() == spv::Op::OpSampledImage) {
    uint32_t clone_id = CloneOriginalImage(
        old_image_inst->GetSingleWordInOperand(kSpvSampledImageImageIdInIdx),
        builder);
    new_image_inst = builder->AddBinaryOp(
        old_image_inst->type_id(), spv::Op::OpSampledImage, clone_id,
        old_image_inst->GetSingleWordInOperand(kSpvSampledImageSamplerIdInIdx));
  } else if (old_image_inst->opcode() == spv::Op::OpImage) {
    uint32_t clone_id = CloneOriginalImage(
        old_image_inst->GetSingleWordInOperand(kSpvImageSampledImageIdInIdx),
        builder);
    new_image_inst = builder->AddUnaryOp(old_image_inst->type_id(),
                                         spv::Op::OpImage, clone_id);
  } else {
    assert(old_image_inst->opcode() == spv::Op::OpCopyObject &&
           "expecting OpCopyObject");
    uint32_t clone_id = CloneOriginalImage(
        old_image_inst->GetSingleWordInOperand(kSpvCopyObjectOperandIdInIdx),
        builder);
    // Since we are cloning, no need to create new copy
    new_image_inst = get_def_use_mgr()->GetDef(clone_id);
  }
  uid2offset_[new_image_inst->unique_id()] =
      uid2offset_[old_image_inst->unique_id()];
  uint32_t new_image_id = new_image_inst->result_id();
  get_decoration_mgr()->CloneDecorations(old_image_id, new_image_id);
  return new_image_id;
}

uint32_t InstBindlessCheckPass::CloneOriginalReference(
    RefAnalysis* ref, InstructionBuilder* builder) {
  // If original is image based, start by cloning descriptor load
  uint32_t new_image_id = 0;
  if (ref->desc_load_id != 0) {
    uint32_t old_image_id =
        ref->ref_inst->GetSingleWordInOperand(kSpvImageSampleImageIdInIdx);
    new_image_id = CloneOriginalImage(old_image_id, builder);
  }
  // Clone original reference
  std::unique_ptr<Instruction> new_ref_inst(ref->ref_inst->Clone(context()));
  uint32_t ref_result_id = ref->ref_inst->result_id();
  uint32_t new_ref_id = 0;
  if (ref_result_id != 0) {
    new_ref_id = TakeNextId();
    new_ref_inst->SetResultId(new_ref_id);
  }
  // Update new ref with new image if created
  if (new_image_id != 0)
    new_ref_inst->SetInOperand(kSpvImageSampleImageIdInIdx, {new_image_id});
  // Register new reference and add to new block
  Instruction* added_inst = builder->AddInstruction(std::move(new_ref_inst));
  uid2offset_[added_inst->unique_id()] =
      uid2offset_[ref->ref_inst->unique_id()];
  if (new_ref_id != 0)
    get_decoration_mgr()->CloneDecorations(ref_result_id, new_ref_id);
  return new_ref_id;
}

uint32_t InstBindlessCheckPass::GetImageId(Instruction* inst) {
  switch (inst->opcode()) {
    case spv::Op::OpImageSampleImplicitLod:
    case spv::Op::OpImageSampleExplicitLod:
    case spv::Op::OpImageSampleDrefImplicitLod:
    case spv::Op::OpImageSampleDrefExplicitLod:
    case spv::Op::OpImageSampleProjImplicitLod:
    case spv::Op::OpImageSampleProjExplicitLod:
    case spv::Op::OpImageSampleProjDrefImplicitLod:
    case spv::Op::OpImageSampleProjDrefExplicitLod:
    case spv::Op::OpImageGather:
    case spv::Op::OpImageDrefGather:
    case spv::Op::OpImageQueryLod:
    case spv::Op::OpImageSparseSampleImplicitLod:
    case spv::Op::OpImageSparseSampleExplicitLod:
    case spv::Op::OpImageSparseSampleDrefImplicitLod:
    case spv::Op::OpImageSparseSampleDrefExplicitLod:
    case spv::Op::OpImageSparseSampleProjImplicitLod:
    case spv::Op::OpImageSparseSampleProjExplicitLod:
    case spv::Op::OpImageSparseSampleProjDrefImplicitLod:
    case spv::Op::OpImageSparseSampleProjDrefExplicitLod:
    case spv::Op::OpImageSparseGather:
    case spv::Op::OpImageSparseDrefGather:
    case spv::Op::OpImageFetch:
    case spv::Op::OpImageRead:
    case spv::Op::OpImageQueryFormat:
    case spv::Op::OpImageQueryOrder:
    case spv::Op::OpImageQuerySizeLod:
    case spv::Op::OpImageQuerySize:
    case spv::Op::OpImageQueryLevels:
    case spv::Op::OpImageQuerySamples:
    case spv::Op::OpImageSparseFetch:
    case spv::Op::OpImageSparseRead:
    case spv::Op::OpImageWrite:
      return inst->GetSingleWordInOperand(kSpvImageSampleImageIdInIdx);
    default:
      break;
  }
  return 0;
}

Instruction* InstBindlessCheckPass::GetPointeeTypeInst(Instruction* ptr_inst) {
  uint32_t pte_ty_id = GetPointeeTypeId(ptr_inst);
  return get_def_use_mgr()->GetDef(pte_ty_id);
}

bool InstBindlessCheckPass::AnalyzeDescriptorReference(Instruction* ref_inst,
                                                       RefAnalysis* ref) {
  ref->ref_inst = ref_inst;
  if (ref_inst->opcode() == spv::Op::OpLoad ||
      ref_inst->opcode() == spv::Op::OpStore) {
    ref->desc_load_id = 0;
    ref->ptr_id = ref_inst->GetSingleWordInOperand(kSpvLoadPtrIdInIdx);
    Instruction* ptr_inst = get_def_use_mgr()->GetDef(ref->ptr_id);
    if (ptr_inst->opcode() != spv::Op::OpAccessChain) return false;
    ref->var_id = ptr_inst->GetSingleWordInOperand(kSpvAccessChainBaseIdInIdx);
    Instruction* var_inst = get_def_use_mgr()->GetDef(ref->var_id);
    if (var_inst->opcode() != spv::Op::OpVariable) return false;
    spv::StorageClass storage_class = spv::StorageClass(
        var_inst->GetSingleWordInOperand(kSpvVariableStorageClassInIdx));
    switch (storage_class) {
      case spv::StorageClass::Uniform:
      case spv::StorageClass::StorageBuffer:
        break;
      default:
        return false;
        break;
    }
    // Check for deprecated storage block form
    if (storage_class == spv::StorageClass::Uniform) {
      uint32_t var_ty_id = var_inst->type_id();
      Instruction* var_ty_inst = get_def_use_mgr()->GetDef(var_ty_id);
      uint32_t ptr_ty_id =
          var_ty_inst->GetSingleWordInOperand(kSpvTypePtrTypeIdInIdx);
      Instruction* ptr_ty_inst = get_def_use_mgr()->GetDef(ptr_ty_id);
      spv::Op ptr_ty_op = ptr_ty_inst->opcode();
      uint32_t block_ty_id =
          (ptr_ty_op == spv::Op::OpTypeArray ||
           ptr_ty_op == spv::Op::OpTypeRuntimeArray)
              ? ptr_ty_inst->GetSingleWordInOperand(kSpvTypeArrayTypeIdInIdx)
              : ptr_ty_id;
      assert(get_def_use_mgr()->GetDef(block_ty_id)->opcode() ==
                 spv::Op::OpTypeStruct &&
             "unexpected block type");
      bool block_found = get_decoration_mgr()->FindDecoration(
          block_ty_id, uint32_t(spv::Decoration::Block),
          [](const Instruction&) { return true; });
      if (!block_found) {
        // If block decoration not found, verify deprecated form of SSBO
        bool buffer_block_found = get_decoration_mgr()->FindDecoration(
            block_ty_id, uint32_t(spv::Decoration::BufferBlock),
            [](const Instruction&) { return true; });
        USE_ASSERT(buffer_block_found && "block decoration not found");
        storage_class = spv::StorageClass::StorageBuffer;
      }
    }
    ref->strg_class = uint32_t(storage_class);
    Instruction* desc_type_inst = GetPointeeTypeInst(var_inst);
    switch (desc_type_inst->opcode()) {
      case spv::Op::OpTypeArray:
      case spv::Op::OpTypeRuntimeArray:
        // A load through a descriptor array will have at least 3 operands. We
        // do not want to instrument loads of descriptors here which are part of
        // an image-based reference.
        if (ptr_inst->NumInOperands() < 3) return false;
        ref->desc_idx_id =
            ptr_inst->GetSingleWordInOperand(kSpvAccessChainIndex0IdInIdx);
        break;
      default:
        break;
    }
    auto decos =
        context()->get_decoration_mgr()->GetDecorationsFor(ref->var_id, false);
    for (const auto& deco : decos) {
      spv::Decoration d = spv::Decoration(deco->GetSingleWordInOperand(1u));
      if (d == spv::Decoration::DescriptorSet) {
        ref->set = deco->GetSingleWordInOperand(2u);
      } else if (d == spv::Decoration::Binding) {
        ref->binding = deco->GetSingleWordInOperand(2u);
      }
    }
    return true;
  }
  // Reference is not load or store. If not an image-based reference, return.
  ref->image_id = GetImageId(ref_inst);
  if (ref->image_id == 0) return false;
  // Search for descriptor load
  uint32_t desc_load_id = ref->image_id;
  Instruction* desc_load_inst;
  for (;;) {
    desc_load_inst = get_def_use_mgr()->GetDef(desc_load_id);
    if (desc_load_inst->opcode() == spv::Op::OpSampledImage)
      desc_load_id =
          desc_load_inst->GetSingleWordInOperand(kSpvSampledImageImageIdInIdx);
    else if (desc_load_inst->opcode() == spv::Op::OpImage)
      desc_load_id =
          desc_load_inst->GetSingleWordInOperand(kSpvImageSampledImageIdInIdx);
    else if (desc_load_inst->opcode() == spv::Op::OpCopyObject)
      desc_load_id =
          desc_load_inst->GetSingleWordInOperand(kSpvCopyObjectOperandIdInIdx);
    else
      break;
  }
  if (desc_load_inst->opcode() != spv::Op::OpLoad) {
    // TODO(greg-lunarg): Handle additional possibilities?
    return false;
  }
  ref->desc_load_id = desc_load_id;
  ref->ptr_id = desc_load_inst->GetSingleWordInOperand(kSpvLoadPtrIdInIdx);
  Instruction* ptr_inst = get_def_use_mgr()->GetDef(ref->ptr_id);
  if (ptr_inst->opcode() == spv::Op::OpVariable) {
    ref->desc_idx_id = 0;
    ref->var_id = ref->ptr_id;
  } else if (ptr_inst->opcode() == spv::Op::OpAccessChain) {
    if (ptr_inst->NumInOperands() != 2) {
      assert(false && "unexpected bindless index number");
      return false;
    }
    ref->desc_idx_id =
        ptr_inst->GetSingleWordInOperand(kSpvAccessChainIndex0IdInIdx);
    ref->var_id = ptr_inst->GetSingleWordInOperand(kSpvAccessChainBaseIdInIdx);
    Instruction* var_inst = get_def_use_mgr()->GetDef(ref->var_id);
    if (var_inst->opcode() != spv::Op::OpVariable) {
      assert(false && "unexpected bindless base");
      return false;
    }
  } else {
    // TODO(greg-lunarg): Handle additional possibilities?
    return false;
  }
  auto decos =
      context()->get_decoration_mgr()->GetDecorationsFor(ref->var_id, false);
  for (const auto& deco : decos) {
    spv::Decoration d = spv::Decoration(deco->GetSingleWordInOperand(1u));
    if (d == spv::Decoration::DescriptorSet) {
      ref->set = deco->GetSingleWordInOperand(2u);
    } else if (d == spv::Decoration::Binding) {
      ref->binding = deco->GetSingleWordInOperand(2u);
    }
  }
  return true;
}

uint32_t InstBindlessCheckPass::FindStride(uint32_t ty_id,
                                           uint32_t stride_deco) {
  uint32_t stride = 0xdeadbeef;
  bool found = get_decoration_mgr()->FindDecoration(
      ty_id, stride_deco, [&stride](const Instruction& deco_inst) {
        stride = deco_inst.GetSingleWordInOperand(2u);
        return true;
      });
  USE_ASSERT(found && "stride not found");
  return stride;
}

uint32_t InstBindlessCheckPass::ByteSize(uint32_t ty_id, uint32_t matrix_stride,
                                         bool col_major, bool in_matrix) {
  analysis::TypeManager* type_mgr = context()->get_type_mgr();
  const analysis::Type* sz_ty = type_mgr->GetType(ty_id);
  if (sz_ty->kind() == analysis::Type::kPointer) {
    // Assuming PhysicalStorageBuffer pointer
    return 8;
  }
  if (sz_ty->kind() == analysis::Type::kMatrix) {
    assert(matrix_stride != 0 && "missing matrix stride");
    const analysis::Matrix* m_ty = sz_ty->AsMatrix();
    if (col_major) {
      return m_ty->element_count() * matrix_stride;
    } else {
      const analysis::Vector* v_ty = m_ty->element_type()->AsVector();
      return v_ty->element_count() * matrix_stride;
    }
  }
  uint32_t size = 1;
  if (sz_ty->kind() == analysis::Type::kVector) {
    const analysis::Vector* v_ty = sz_ty->AsVector();
    size = v_ty->element_count();
    const analysis::Type* comp_ty = v_ty->element_type();
    // if vector in row major matrix, the vector is strided so return the
    // number of bytes spanned by the vector
    if (in_matrix && !col_major && matrix_stride > 0) {
      uint32_t comp_ty_id = type_mgr->GetId(comp_ty);
      return (size - 1) * matrix_stride + ByteSize(comp_ty_id, 0, false, false);
    }
    sz_ty = comp_ty;
  }
  switch (sz_ty->kind()) {
    case analysis::Type::kFloat: {
      const analysis::Float* f_ty = sz_ty->AsFloat();
      size *= f_ty->width();
    } break;
    case analysis::Type::kInteger: {
      const analysis::Integer* i_ty = sz_ty->AsInteger();
      size *= i_ty->width();
    } break;
    default: { assert(false && "unexpected type"); } break;
  }
  size /= 8;
  return size;
}

uint32_t InstBindlessCheckPass::GenLastByteIdx(RefAnalysis* ref,
                                               InstructionBuilder* builder) {
  // Find outermost buffer type and its access chain index
  Instruction* var_inst = get_def_use_mgr()->GetDef(ref->var_id);
  Instruction* desc_ty_inst = GetPointeeTypeInst(var_inst);
  uint32_t buff_ty_id;
  uint32_t ac_in_idx = 1;
  switch (desc_ty_inst->opcode()) {
    case spv::Op::OpTypeArray:
    case spv::Op::OpTypeRuntimeArray:
      buff_ty_id = desc_ty_inst->GetSingleWordInOperand(0);
      ++ac_in_idx;
      break;
    default:
      assert(desc_ty_inst->opcode() == spv::Op::OpTypeStruct &&
             "unexpected descriptor type");
      buff_ty_id = desc_ty_inst->result_id();
      break;
  }
  // Process remaining access chain indices
  Instruction* ac_inst = get_def_use_mgr()->GetDef(ref->ptr_id);
  uint32_t curr_ty_id = buff_ty_id;
  uint32_t sum_id = 0u;
  uint32_t matrix_stride = 0u;
  bool col_major = false;
  uint32_t matrix_stride_id = 0u;
  bool in_matrix = false;
  while (ac_in_idx < ac_inst->NumInOperands()) {
    uint32_t curr_idx_id = ac_inst->GetSingleWordInOperand(ac_in_idx);
    Instruction* curr_ty_inst = get_def_use_mgr()->GetDef(curr_ty_id);
    uint32_t curr_offset_id = 0;
    switch (curr_ty_inst->opcode()) {
      case spv::Op::OpTypeArray:
      case spv::Op::OpTypeRuntimeArray: {
        // Get array stride and multiply by current index
        uint32_t arr_stride =
            FindStride(curr_ty_id, uint32_t(spv::Decoration::ArrayStride));
        uint32_t arr_stride_id = builder->GetUintConstantId(arr_stride);
        uint32_t curr_idx_32b_id = Gen32BitCvtCode(curr_idx_id, builder);
        Instruction* curr_offset_inst = builder->AddBinaryOp(
            GetUintId(), spv::Op::OpIMul, arr_stride_id, curr_idx_32b_id);
        curr_offset_id = curr_offset_inst->result_id();
        // Get element type for next step
        curr_ty_id = curr_ty_inst->GetSingleWordInOperand(0);
      } break;
      case spv::Op::OpTypeMatrix: {
        assert(matrix_stride != 0 && "missing matrix stride");
        matrix_stride_id = builder->GetUintConstantId(matrix_stride);
        uint32_t vec_ty_id = curr_ty_inst->GetSingleWordInOperand(0);
        // If column major, multiply column index by matrix stride, otherwise
        // by vector component size and save matrix stride for vector (row)
        // index
        uint32_t col_stride_id;
        if (col_major) {
          col_stride_id = matrix_stride_id;
        } else {
          Instruction* vec_ty_inst = get_def_use_mgr()->GetDef(vec_ty_id);
          uint32_t comp_ty_id = vec_ty_inst->GetSingleWordInOperand(0u);
          uint32_t col_stride = ByteSize(comp_ty_id, 0u, false, false);
          col_stride_id = builder->GetUintConstantId(col_stride);
        }
        uint32_t curr_idx_32b_id = Gen32BitCvtCode(curr_idx_id, builder);
        Instruction* curr_offset_inst = builder->AddBinaryOp(
            GetUintId(), spv::Op::OpIMul, col_stride_id, curr_idx_32b_id);
        curr_offset_id = curr_offset_inst->result_id();
        // Get element type for next step
        curr_ty_id = vec_ty_id;
        in_matrix = true;
      } break;
      case spv::Op::OpTypeVector: {
        // If inside a row major matrix type, multiply index by matrix stride,
        // else multiply by component size
        uint32_t comp_ty_id = curr_ty_inst->GetSingleWordInOperand(0u);
        uint32_t curr_idx_32b_id = Gen32BitCvtCode(curr_idx_id, builder);
        if (in_matrix && !col_major) {
          Instruction* curr_offset_inst = builder->AddBinaryOp(
              GetUintId(), spv::Op::OpIMul, matrix_stride_id, curr_idx_32b_id);
          curr_offset_id = curr_offset_inst->result_id();
        } else {
          uint32_t comp_ty_sz = ByteSize(comp_ty_id, 0u, false, false);
          uint32_t comp_ty_sz_id = builder->GetUintConstantId(comp_ty_sz);
          Instruction* curr_offset_inst = builder->AddBinaryOp(
              GetUintId(), spv::Op::OpIMul, comp_ty_sz_id, curr_idx_32b_id);
          curr_offset_id = curr_offset_inst->result_id();
        }
        // Get element type for next step
        curr_ty_id = comp_ty_id;
      } break;
      case spv::Op::OpTypeStruct: {
        // Get buffer byte offset for the referenced member
        Instruction* curr_idx_inst = get_def_use_mgr()->GetDef(curr_idx_id);
        assert(curr_idx_inst->opcode() == spv::Op::OpConstant &&
               "unexpected struct index");
        uint32_t member_idx = curr_idx_inst->GetSingleWordInOperand(0);
        uint32_t member_offset = 0xdeadbeef;
        bool found = get_decoration_mgr()->FindDecoration(
            curr_ty_id, uint32_t(spv::Decoration::Offset),
            [&member_idx, &member_offset](const Instruction& deco_inst) {
              if (deco_inst.GetSingleWordInOperand(1u) != member_idx)
                return false;
              member_offset = deco_inst.GetSingleWordInOperand(3u);
              return true;
            });
        USE_ASSERT(found && "member offset not found");
        curr_offset_id = builder->GetUintConstantId(member_offset);
        // Look for matrix stride for this member if there is one. The matrix
        // stride is not on the matrix type, but in a OpMemberDecorate on the
        // enclosing struct type at the member index. If none found, reset
        // stride to 0.
        found = get_decoration_mgr()->FindDecoration(
            curr_ty_id, uint32_t(spv::Decoration::MatrixStride),
            [&member_idx, &matrix_stride](const Instruction& deco_inst) {
              if (deco_inst.GetSingleWordInOperand(1u) != member_idx)
                return false;
              matrix_stride = deco_inst.GetSingleWordInOperand(3u);
              return true;
            });
        if (!found) matrix_stride = 0;
        // Look for column major decoration
        found = get_decoration_mgr()->FindDecoration(
            curr_ty_id, uint32_t(spv::Decoration::ColMajor),
            [&member_idx, &col_major](const Instruction& deco_inst) {
              if (deco_inst.GetSingleWordInOperand(1u) != member_idx)
                return false;
              col_major = true;
              return true;
            });
        if (!found) col_major = false;
        // Get element type for next step
        curr_ty_id = curr_ty_inst->GetSingleWordInOperand(member_idx);
      } break;
      default: { assert(false && "unexpected non-composite type"); } break;
    }
    if (sum_id == 0)
      sum_id = curr_offset_id;
    else {
      Instruction* sum_inst =
          builder->AddIAdd(GetUintId(), sum_id, curr_offset_id);
      sum_id = sum_inst->result_id();
    }
    ++ac_in_idx;
  }
  // Add in offset of last byte of referenced object
  uint32_t bsize = ByteSize(curr_ty_id, matrix_stride, col_major, in_matrix);
  uint32_t last = bsize - 1;
  uint32_t last_id = builder->GetUintConstantId(last);
  Instruction* sum_inst = builder->AddIAdd(GetUintId(), sum_id, last_id);
  return sum_inst->result_id();
}

void InstBindlessCheckPass::GenCheckCode(
    uint32_t check_id, RefAnalysis* ref,
    std::vector<std::unique_ptr<BasicBlock>>* new_blocks) {
  BasicBlock* back_blk_ptr = &*new_blocks->back();
  InstructionBuilder builder(
      context(), back_blk_ptr,
      IRContext::kAnalysisDefUse | IRContext::kAnalysisInstrToBlockMapping);
  // Gen conditional branch on check_id. Valid branch generates original
  // reference. Invalid generates debug output and zero result (if needed).
  uint32_t merge_blk_id = TakeNextId();
  uint32_t valid_blk_id = TakeNextId();
  uint32_t invalid_blk_id = TakeNextId();
  std::unique_ptr<Instruction> merge_label(NewLabel(merge_blk_id));
  std::unique_ptr<Instruction> valid_label(NewLabel(valid_blk_id));
  std::unique_ptr<Instruction> invalid_label(NewLabel(invalid_blk_id));
  (void)builder.AddConditionalBranch(
      check_id, valid_blk_id, invalid_blk_id, merge_blk_id,
      uint32_t(spv::SelectionControlMask::MaskNone));
  // Gen valid bounds branch
  std::unique_ptr<BasicBlock> new_blk_ptr(
      new BasicBlock(std::move(valid_label)));
  builder.SetInsertPoint(&*new_blk_ptr);
  uint32_t new_ref_id = CloneOriginalReference(ref, &builder);
  uint32_t null_id = 0;
  uint32_t ref_type_id = ref->ref_inst->type_id();
  (void)builder.AddBranch(merge_blk_id);
  new_blocks->push_back(std::move(new_blk_ptr));
  // Gen invalid block
  new_blk_ptr.reset(new BasicBlock(std::move(invalid_label)));
  builder.SetInsertPoint(&*new_blk_ptr);

  // Generate a ConstantNull, converting to uint64 if the type cannot be a null.
  if (new_ref_id != 0) {
    analysis::TypeManager* type_mgr = context()->get_type_mgr();
    analysis::Type* ref_type = type_mgr->GetType(ref_type_id);
    if (ref_type->AsPointer() != nullptr) {
      context()->AddCapability(spv::Capability::Int64);
      uint32_t null_u64_id = GetNullId(GetUint64Id());
      Instruction* null_ptr_inst = builder.AddUnaryOp(
          ref_type_id, spv::Op::OpConvertUToPtr, null_u64_id);
      null_id = null_ptr_inst->result_id();
    } else {
      null_id = GetNullId(ref_type_id);
    }
  }
  // Remember last invalid block id
  uint32_t last_invalid_blk_id = new_blk_ptr->GetLabelInst()->result_id();
  // Gen zero for invalid  reference
  (void)builder.AddBranch(merge_blk_id);
  new_blocks->push_back(std::move(new_blk_ptr));
  // Gen merge block
  new_blk_ptr.reset(new BasicBlock(std::move(merge_label)));
  builder.SetInsertPoint(&*new_blk_ptr);
  // Gen phi of new reference and zero, if necessary, and replace the
  // result id of the original reference with that of the Phi. Kill original
  // reference.
  if (new_ref_id != 0) {
    Instruction* phi_inst = builder.AddPhi(
        ref_type_id, {new_ref_id, valid_blk_id, null_id, last_invalid_blk_id});
    context()->ReplaceAllUsesWith(ref->ref_inst->result_id(),
                                  phi_inst->result_id());
  }
  new_blocks->push_back(std::move(new_blk_ptr));
  context()->KillInst(ref->ref_inst);
}

void InstBindlessCheckPass::GenDescCheckCode(
    BasicBlock::iterator ref_inst_itr,
    UptrVectorIterator<BasicBlock> ref_block_itr, uint32_t stage_idx,
    std::vector<std::unique_ptr<BasicBlock>>* new_blocks) {
  // Look for reference through descriptor. If not, return.
  RefAnalysis ref;
  if (!AnalyzeDescriptorReference(&*ref_inst_itr, &ref)) return;
  std::unique_ptr<BasicBlock> new_blk_ptr;
  // Move original block's preceding instructions into first new block
  MovePreludeCode(ref_inst_itr, ref_block_itr, &new_blk_ptr);
  InstructionBuilder builder(
      context(), &*new_blk_ptr,
      IRContext::kAnalysisDefUse | IRContext::kAnalysisInstrToBlockMapping);
  new_blocks->push_back(std::move(new_blk_ptr));
  // Determine if we can only do initialization check
  uint32_t ref_id = builder.GetUintConstantId(0u);
  spv::Op op = ref.ref_inst->opcode();
  if (ref.desc_load_id != 0) {
    uint32_t num_in_oprnds = ref.ref_inst->NumInOperands();
    if ((op == spv::Op::OpImageRead && num_in_oprnds == 2) ||
        (op == spv::Op::OpImageFetch && num_in_oprnds == 2) ||
        (op == spv::Op::OpImageWrite && num_in_oprnds == 3)) {
      Instruction* image_inst = get_def_use_mgr()->GetDef(ref.image_id);
      uint32_t image_ty_id = image_inst->type_id();
      Instruction* image_ty_inst = get_def_use_mgr()->GetDef(image_ty_id);
      if (spv::Dim(image_ty_inst->GetSingleWordInOperand(kSpvTypeImageDim)) ==
          spv::Dim::Buffer) {
        if ((image_ty_inst->GetSingleWordInOperand(kSpvTypeImageDepth) == 0) &&
            (image_ty_inst->GetSingleWordInOperand(kSpvTypeImageArrayed) ==
             0) &&
            (image_ty_inst->GetSingleWordInOperand(kSpvTypeImageMS) == 0)) {
          ref_id = GenUintCastCode(ref.ref_inst->GetSingleWordInOperand(1),
                                   &builder);
        }
      }
    }
  } else {
    // For now, only do bounds check for non-aggregate types. Otherwise
    // just do descriptor initialization check.
    // TODO(greg-lunarg): Do bounds check for aggregate loads and stores
    Instruction* ref_ptr_inst = get_def_use_mgr()->GetDef(ref.ptr_id);
    Instruction* pte_type_inst = GetPointeeTypeInst(ref_ptr_inst);
    spv::Op pte_type_op = pte_type_inst->opcode();
    if (pte_type_op != spv::Op::OpTypeArray &&
        pte_type_op != spv::Op::OpTypeRuntimeArray &&
        pte_type_op != spv::Op::OpTypeStruct) {
      ref_id = GenLastByteIdx(&ref, &builder);
    }
  }
  // Read initialization/bounds from debug input buffer. If index id not yet
  // set, binding is single descriptor, so set index to constant 0.
  if (ref.desc_idx_id == 0) ref.desc_idx_id = builder.GetUintConstantId(0u);
  uint32_t check_id =
      GenDescCheckCall(ref.ref_inst->unique_id(), stage_idx, ref.var_id,
                       ref.desc_idx_id, ref_id, &builder);

  // Generate runtime initialization/bounds test code with true branch
  // being full reference and false branch being zero
  // for the referenced value.
  GenCheckCode(check_id, &ref, new_blocks);

  // Move original block's remaining code into remainder/merge block and add
  // to new blocks
  BasicBlock* back_blk_ptr = &*new_blocks->back();
  MovePostludeCode(ref_block_itr, back_blk_ptr);
}

void InstBindlessCheckPass::InitializeInstBindlessCheck() {
  // Initialize base class
  InitializeInstrument();
  for (auto& anno : get_module()->annotations()) {
    if (anno.opcode() == spv::Op::OpDecorate) {
      if (spv::Decoration(anno.GetSingleWordInOperand(1u)) ==
          spv::Decoration::DescriptorSet) {
        var2desc_set_[anno.GetSingleWordInOperand(0u)] =
            anno.GetSingleWordInOperand(2u);
      } else if (spv::Decoration(anno.GetSingleWordInOperand(1u)) ==
                 spv::Decoration::Binding) {
        var2binding_[anno.GetSingleWordInOperand(0u)] =
            anno.GetSingleWordInOperand(2u);
      }
    }
  }
}

Pass::Status InstBindlessCheckPass::ProcessImpl() {
  // The memory model and linkage must always be updated for spirv-link to work
  // correctly.
  AddStorageBufferExt();
  if (!get_feature_mgr()->HasExtension(kSPV_KHR_physical_storage_buffer)) {
    context()->AddExtension("SPV_KHR_physical_storage_buffer");
  }

  context()->AddCapability(spv::Capability::PhysicalStorageBufferAddresses);
  Instruction* memory_model = get_module()->GetMemoryModel();
  memory_model->SetInOperand(
      0u, {uint32_t(spv::AddressingModel::PhysicalStorageBuffer64)});

  context()->AddCapability(spv::Capability::Linkage);

  InstProcessFunction pfn =
      [this](BasicBlock::iterator ref_inst_itr,
             UptrVectorIterator<BasicBlock> ref_block_itr, uint32_t stage_idx,
             std::vector<std::unique_ptr<BasicBlock>>* new_blocks) {
        return GenDescCheckCode(ref_inst_itr, ref_block_itr, stage_idx,
                                new_blocks);
      };

  InstProcessEntryPointCallTree(pfn);
  // This pass always changes the memory model, so that linking will work
  // properly.
  return Status::SuccessWithChange;
}

Pass::Status InstBindlessCheckPass::Process() {
  InitializeInstBindlessCheck();
  return ProcessImpl();
}

}  // namespace opt
}  // namespace spvtools