SPIRV-Tools/source/opt/desc_sroa_util.cpp

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// Copyright (c) 2021 Google LLC
//
// 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 "source/opt/desc_sroa_util.h"
namespace spvtools {
namespace opt {
namespace {
const uint32_t kOpAccessChainInOperandIndexes = 1;
// Returns the length of array type |type|.
uint32_t GetLengthOfArrayType(IRContext* context, Instruction* type) {
assert(type->opcode() == SpvOpTypeArray && "type must be array");
uint32_t length_id = type->GetSingleWordInOperand(1);
const analysis::Constant* length_const =
context->get_constant_mgr()->FindDeclaredConstant(length_id);
assert(length_const != nullptr);
return length_const->GetU32();
}
} // namespace
namespace descsroautil {
bool IsDescriptorArray(IRContext* context, Instruction* var) {
if (var->opcode() != SpvOpVariable) {
return false;
}
uint32_t ptr_type_id = var->type_id();
Instruction* ptr_type_inst = context->get_def_use_mgr()->GetDef(ptr_type_id);
if (ptr_type_inst->opcode() != SpvOpTypePointer) {
return false;
}
uint32_t var_type_id = ptr_type_inst->GetSingleWordInOperand(1);
Instruction* var_type_inst = context->get_def_use_mgr()->GetDef(var_type_id);
if (var_type_inst->opcode() != SpvOpTypeArray &&
var_type_inst->opcode() != SpvOpTypeStruct) {
return false;
}
// All structures with descriptor assignments must be replaced by variables,
// one for each of their members - with the exceptions of buffers.
if (IsTypeOfStructuredBuffer(context, var_type_inst)) {
return false;
}
if (!context->get_decoration_mgr()->HasDecoration(
var->result_id(), SpvDecorationDescriptorSet)) {
return false;
}
return context->get_decoration_mgr()->HasDecoration(var->result_id(),
SpvDecorationBinding);
}
bool IsTypeOfStructuredBuffer(IRContext* context, const Instruction* type) {
if (type->opcode() != SpvOpTypeStruct) {
return false;
}
// All buffers have offset decorations for members of their structure types.
// This is how we distinguish it from a structure of descriptors.
return context->get_decoration_mgr()->HasDecoration(type->result_id(),
SpvDecorationOffset);
}
const analysis::Constant* GetAccessChainIndexAsConst(
IRContext* context, Instruction* access_chain) {
if (access_chain->NumInOperands() <= 1) {
return nullptr;
}
uint32_t idx_id = GetFirstIndexOfAccessChain(access_chain);
const analysis::Constant* idx_const =
context->get_constant_mgr()->FindDeclaredConstant(idx_id);
return idx_const;
}
uint32_t GetFirstIndexOfAccessChain(Instruction* access_chain) {
assert(access_chain->NumInOperands() > 1 &&
"OpAccessChain does not have Indexes operand");
return access_chain->GetSingleWordInOperand(kOpAccessChainInOperandIndexes);
}
uint32_t GetNumberOfElementsForArrayOrStruct(IRContext* context,
Instruction* var) {
uint32_t ptr_type_id = var->type_id();
Instruction* ptr_type_inst = context->get_def_use_mgr()->GetDef(ptr_type_id);
assert(ptr_type_inst->opcode() == SpvOpTypePointer &&
"Variable should be a pointer to an array or structure.");
uint32_t pointee_type_id = ptr_type_inst->GetSingleWordInOperand(1);
Instruction* pointee_type_inst =
context->get_def_use_mgr()->GetDef(pointee_type_id);
if (pointee_type_inst->opcode() == SpvOpTypeArray) {
return GetLengthOfArrayType(context, pointee_type_inst);
}
assert(pointee_type_inst->opcode() == SpvOpTypeStruct &&
"Variable should be a pointer to an array or structure.");
return pointee_type_inst->NumInOperands();
}
} // namespace descsroautil
} // namespace opt
} // namespace spvtools