SPIRV-Tools/source/val/function.cpp
alan-baker aea4e6b1b9 Fix block depth rule priority (#2755)
Fixes #2743

* Continue depth calculation should take precedence over merge calculation
2019-07-23 13:57:44 -04:00

421 lines
14 KiB
C++

// Copyright (c) 2015-2016 The Khronos Group 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 "source/val/function.h"
#include <cassert>
#include <algorithm>
#include <sstream>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include "source/cfa.h"
#include "source/val/basic_block.h"
#include "source/val/construct.h"
#include "source/val/validate.h"
namespace spvtools {
namespace val {
// Universal Limit of ResultID + 1
static const uint32_t kInvalidId = 0x400000;
Function::Function(uint32_t function_id, uint32_t result_type_id,
SpvFunctionControlMask function_control,
uint32_t function_type_id)
: id_(function_id),
function_type_id_(function_type_id),
result_type_id_(result_type_id),
function_control_(function_control),
declaration_type_(FunctionDecl::kFunctionDeclUnknown),
end_has_been_registered_(false),
blocks_(),
current_block_(nullptr),
pseudo_entry_block_(0),
pseudo_exit_block_(kInvalidId),
cfg_constructs_(),
variable_ids_(),
parameter_ids_() {}
bool Function::IsFirstBlock(uint32_t block_id) const {
return !ordered_blocks_.empty() && *first_block() == block_id;
}
spv_result_t Function::RegisterFunctionParameter(uint32_t parameter_id,
uint32_t type_id) {
assert(current_block_ == nullptr &&
"RegisterFunctionParameter can only be called when parsing the binary "
"ouside of a block");
// TODO(umar): Validate function parameter type order and count
// TODO(umar): Use these variables to validate parameter type
(void)parameter_id;
(void)type_id;
return SPV_SUCCESS;
}
spv_result_t Function::RegisterLoopMerge(uint32_t merge_id,
uint32_t continue_id) {
RegisterBlock(merge_id, false);
RegisterBlock(continue_id, false);
BasicBlock& merge_block = blocks_.at(merge_id);
BasicBlock& continue_target_block = blocks_.at(continue_id);
assert(current_block_ &&
"RegisterLoopMerge must be called when called within a block");
current_block_->set_type(kBlockTypeLoop);
merge_block.set_type(kBlockTypeMerge);
continue_target_block.set_type(kBlockTypeContinue);
Construct& loop_construct =
AddConstruct({ConstructType::kLoop, current_block_, &merge_block});
Construct& continue_construct =
AddConstruct({ConstructType::kContinue, &continue_target_block});
continue_construct.set_corresponding_constructs({&loop_construct});
loop_construct.set_corresponding_constructs({&continue_construct});
merge_block_header_[&merge_block] = current_block_;
if (continue_target_headers_.find(&continue_target_block) ==
continue_target_headers_.end()) {
continue_target_headers_[&continue_target_block] = {current_block_};
} else {
continue_target_headers_[&continue_target_block].push_back(current_block_);
}
return SPV_SUCCESS;
}
spv_result_t Function::RegisterSelectionMerge(uint32_t merge_id) {
RegisterBlock(merge_id, false);
BasicBlock& merge_block = blocks_.at(merge_id);
current_block_->set_type(kBlockTypeHeader);
merge_block.set_type(kBlockTypeMerge);
merge_block_header_[&merge_block] = current_block_;
AddConstruct({ConstructType::kSelection, current_block(), &merge_block});
return SPV_SUCCESS;
}
spv_result_t Function::RegisterSetFunctionDeclType(FunctionDecl type) {
assert(declaration_type_ == FunctionDecl::kFunctionDeclUnknown);
declaration_type_ = type;
return SPV_SUCCESS;
}
spv_result_t Function::RegisterBlock(uint32_t block_id, bool is_definition) {
assert(
declaration_type_ == FunctionDecl::kFunctionDeclDefinition &&
"RegisterBlocks can only be called after declaration_type_ is defined");
std::unordered_map<uint32_t, BasicBlock>::iterator inserted_block;
bool success = false;
tie(inserted_block, success) =
blocks_.insert({block_id, BasicBlock(block_id)});
if (is_definition) { // new block definition
assert(current_block_ == nullptr &&
"Register Block can only be called when parsing a binary outside of "
"a BasicBlock");
undefined_blocks_.erase(block_id);
current_block_ = &inserted_block->second;
ordered_blocks_.push_back(current_block_);
if (IsFirstBlock(block_id)) current_block_->set_reachable(true);
} else if (success) { // Block doesn't exsist but this is not a definition
undefined_blocks_.insert(block_id);
}
return SPV_SUCCESS;
}
void Function::RegisterBlockEnd(std::vector<uint32_t> next_list,
SpvOp branch_instruction) {
assert(
current_block_ &&
"RegisterBlockEnd can only be called when parsing a binary in a block");
std::vector<BasicBlock*> next_blocks;
next_blocks.reserve(next_list.size());
std::unordered_map<uint32_t, BasicBlock>::iterator inserted_block;
bool success;
for (uint32_t successor_id : next_list) {
tie(inserted_block, success) =
blocks_.insert({successor_id, BasicBlock(successor_id)});
if (success) {
undefined_blocks_.insert(successor_id);
}
next_blocks.push_back(&inserted_block->second);
}
if (current_block_->is_type(kBlockTypeLoop)) {
// For each loop header, record the set of its successors, and include
// its continue target if the continue target is not the loop header
// itself.
std::vector<BasicBlock*>& next_blocks_plus_continue_target =
loop_header_successors_plus_continue_target_map_[current_block_];
next_blocks_plus_continue_target = next_blocks;
auto continue_target =
FindConstructForEntryBlock(current_block_, ConstructType::kLoop)
.corresponding_constructs()
.back()
->entry_block();
if (continue_target != current_block_) {
next_blocks_plus_continue_target.push_back(continue_target);
}
}
current_block_->RegisterBranchInstruction(branch_instruction);
current_block_->RegisterSuccessors(next_blocks);
current_block_ = nullptr;
return;
}
void Function::RegisterFunctionEnd() {
if (!end_has_been_registered_) {
end_has_been_registered_ = true;
ComputeAugmentedCFG();
}
}
size_t Function::block_count() const { return blocks_.size(); }
size_t Function::undefined_block_count() const {
return undefined_blocks_.size();
}
const std::vector<BasicBlock*>& Function::ordered_blocks() const {
return ordered_blocks_;
}
std::vector<BasicBlock*>& Function::ordered_blocks() { return ordered_blocks_; }
const BasicBlock* Function::current_block() const { return current_block_; }
BasicBlock* Function::current_block() { return current_block_; }
const std::list<Construct>& Function::constructs() const {
return cfg_constructs_;
}
std::list<Construct>& Function::constructs() { return cfg_constructs_; }
const BasicBlock* Function::first_block() const {
if (ordered_blocks_.empty()) return nullptr;
return ordered_blocks_[0];
}
BasicBlock* Function::first_block() {
if (ordered_blocks_.empty()) return nullptr;
return ordered_blocks_[0];
}
bool Function::IsBlockType(uint32_t merge_block_id, BlockType type) const {
bool ret = false;
const BasicBlock* block;
std::tie(block, std::ignore) = GetBlock(merge_block_id);
if (block) {
ret = block->is_type(type);
}
return ret;
}
std::pair<const BasicBlock*, bool> Function::GetBlock(uint32_t block_id) const {
const auto b = blocks_.find(block_id);
if (b != end(blocks_)) {
const BasicBlock* block = &(b->second);
bool defined =
undefined_blocks_.find(block->id()) == std::end(undefined_blocks_);
return std::make_pair(block, defined);
} else {
return std::make_pair(nullptr, false);
}
}
std::pair<BasicBlock*, bool> Function::GetBlock(uint32_t block_id) {
const BasicBlock* out;
bool defined;
std::tie(out, defined) =
const_cast<const Function*>(this)->GetBlock(block_id);
return std::make_pair(const_cast<BasicBlock*>(out), defined);
}
Function::GetBlocksFunction Function::AugmentedCFGSuccessorsFunction() const {
return [this](const BasicBlock* block) {
auto where = augmented_successors_map_.find(block);
return where == augmented_successors_map_.end() ? block->successors()
: &(*where).second;
};
}
Function::GetBlocksFunction
Function::AugmentedCFGSuccessorsFunctionIncludingHeaderToContinueEdge() const {
return [this](const BasicBlock* block) {
auto where = loop_header_successors_plus_continue_target_map_.find(block);
return where == loop_header_successors_plus_continue_target_map_.end()
? AugmentedCFGSuccessorsFunction()(block)
: &(*where).second;
};
}
Function::GetBlocksFunction Function::AugmentedCFGPredecessorsFunction() const {
return [this](const BasicBlock* block) {
auto where = augmented_predecessors_map_.find(block);
return where == augmented_predecessors_map_.end() ? block->predecessors()
: &(*where).second;
};
}
void Function::ComputeAugmentedCFG() {
// Compute the successors of the pseudo-entry block, and
// the predecessors of the pseudo exit block.
auto succ_func = [](const BasicBlock* b) { return b->successors(); };
auto pred_func = [](const BasicBlock* b) { return b->predecessors(); };
CFA<BasicBlock>::ComputeAugmentedCFG(
ordered_blocks_, &pseudo_entry_block_, &pseudo_exit_block_,
&augmented_successors_map_, &augmented_predecessors_map_, succ_func,
pred_func);
}
Construct& Function::AddConstruct(const Construct& new_construct) {
cfg_constructs_.push_back(new_construct);
auto& result = cfg_constructs_.back();
entry_block_to_construct_[std::make_pair(new_construct.entry_block(),
new_construct.type())] = &result;
return result;
}
Construct& Function::FindConstructForEntryBlock(const BasicBlock* entry_block,
ConstructType type) {
auto where =
entry_block_to_construct_.find(std::make_pair(entry_block, type));
assert(where != entry_block_to_construct_.end());
auto construct_ptr = (*where).second;
assert(construct_ptr);
return *construct_ptr;
}
int Function::GetBlockDepth(BasicBlock* bb) {
// Guard against nullptr.
if (!bb) {
return 0;
}
// Only calculate the depth if it's not already calculated.
// This function uses memoization to avoid duplicate CFG depth calculations.
if (block_depth_.find(bb) != block_depth_.end()) {
return block_depth_[bb];
}
BasicBlock* bb_dom = bb->immediate_dominator();
if (!bb_dom || bb == bb_dom) {
// This block has no dominator, so it's at depth 0.
block_depth_[bb] = 0;
} else if (bb->is_type(kBlockTypeContinue)) {
// This rule must precede the rule for merge blocks in order to set up
// depths correctly. If a block is both a merge and continue then the merge
// is nested within the continue's loop (or the graph is incorrect).
// The depth of the continue block entry point is 1 + loop header depth.
Construct* continue_construct =
entry_block_to_construct_[std::make_pair(bb, ConstructType::kContinue)];
assert(continue_construct);
// Continue construct has only 1 corresponding construct (loop header).
Construct* loop_construct =
continue_construct->corresponding_constructs()[0];
assert(loop_construct);
BasicBlock* loop_header = loop_construct->entry_block();
// The continue target may be the loop itself (while 1).
// In such cases, the depth of the continue block is: 1 + depth of the
// loop's dominator block.
if (loop_header == bb) {
block_depth_[bb] = 1 + GetBlockDepth(bb_dom);
} else {
block_depth_[bb] = 1 + GetBlockDepth(loop_header);
}
} else if (bb->is_type(kBlockTypeMerge)) {
// If this is a merge block, its depth is equal to the block before
// branching.
BasicBlock* header = merge_block_header_[bb];
assert(header);
block_depth_[bb] = GetBlockDepth(header);
} else if (bb_dom->is_type(kBlockTypeHeader) ||
bb_dom->is_type(kBlockTypeLoop)) {
// The dominator of the given block is a header block. So, the nesting
// depth of this block is: 1 + nesting depth of the header.
block_depth_[bb] = 1 + GetBlockDepth(bb_dom);
} else {
block_depth_[bb] = GetBlockDepth(bb_dom);
}
return block_depth_[bb];
}
void Function::RegisterExecutionModelLimitation(SpvExecutionModel model,
const std::string& message) {
execution_model_limitations_.push_back(
[model, message](SpvExecutionModel in_model, std::string* out_message) {
if (model != in_model) {
if (out_message) {
*out_message = message;
}
return false;
}
return true;
});
}
bool Function::IsCompatibleWithExecutionModel(SpvExecutionModel model,
std::string* reason) const {
bool return_value = true;
std::stringstream ss_reason;
for (const auto& is_compatible : execution_model_limitations_) {
std::string message;
if (!is_compatible(model, &message)) {
if (!reason) return false;
return_value = false;
if (!message.empty()) {
ss_reason << message << "\n";
}
}
}
if (!return_value && reason) {
*reason = ss_reason.str();
}
return return_value;
}
bool Function::CheckLimitations(const ValidationState_t& _,
const Function* entry_point,
std::string* reason) const {
bool return_value = true;
std::stringstream ss_reason;
for (const auto& is_compatible : limitations_) {
std::string message;
if (!is_compatible(_, entry_point, &message)) {
if (!reason) return false;
return_value = false;
if (!message.empty()) {
ss_reason << message << "\n";
}
}
}
if (!return_value && reason) {
*reason = ss_reason.str();
}
return return_value;
}
} // namespace val
} // namespace spvtools