SPIRV-Tools/source/opt/cfg.h
Diego Novillo 9d6cc26226 Move class CFG from namespace opt to namespace ir.
It makes more sense to have the CFG inside the ir name space, as it is
descriptive of the representation.
2017-11-02 11:51:07 -04:00

111 lines
3.9 KiB
C++

// Copyright (c) 2017 Google 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.
#ifndef LIBSPIRV_OPT_CFG_H_
#define LIBSPIRV_OPT_CFG_H_
#include "basic_block.h"
#include <list>
#include <unordered_map>
namespace spvtools {
namespace ir {
class CFG {
public:
CFG(ir::Module* module);
// Return the module described by this CFG.
ir::Module* get_module() const { return module_; }
// Return the list of predecesors for basic block with label |blkid|.
// TODO(dnovillo): Move this to ir::BasicBlock.
const std::vector<uint32_t>& preds(uint32_t blk_id) const {
return label2preds_.at(blk_id);
}
// Return a pointer to the basic block instance corresponding to the label
// |blk_id|.
ir::BasicBlock* block(uint32_t blk_id) const { return id2block_.at(blk_id); }
// Return the pseudo entry and exit blocks. TODO(dnovillo): Remove when
// LocalSingleStoreElimPass::CalculateImmediateDominators() is moved into this
// class.
const ir::BasicBlock* pseudo_entry_block() const {
return &pseudo_entry_block_;
}
ir::BasicBlock* pseudo_entry_block() { return &pseudo_entry_block_; }
const ir::BasicBlock* pseudo_exit_block() const {
return &pseudo_exit_block_;
}
ir::BasicBlock* pseudo_exit_block() { return &pseudo_exit_block_; }
// Return true if |block_ptr| is the pseudo-entry block.
bool IsPseudoEntryBlock(ir::BasicBlock* block_ptr) const {
return block_ptr == &pseudo_entry_block_;
}
// Return true if |block_ptr| is the pseudo-exit block.
bool IsPseudoExitBlock(ir::BasicBlock* block_ptr) const {
return block_ptr == &pseudo_exit_block_;
}
// Compute structured block order into |structuredOrder| for |func| starting
// at |root|. This order has the property that dominators come before all
// blocks they dominate and merge blocks come after all blocks that are in
// the control constructs of their header.
void ComputeStructuredOrder(ir::Function* func, ir::BasicBlock* root,
std::list<ir::BasicBlock*>* order);
private:
using cbb_ptr = const ir::BasicBlock*;
// Compute structured successors for function |func|. A block's structured
// successors are the blocks it branches to together with its declared merge
// block and continue block if it has them. When order matters, the merge
// block and continue block always appear first. This assures correct depth
// first search in the presence of early returns and kills. If the successor
// vector contain duplicates of the merge or continue blocks, they are safely
// ignored by DFS.
void ComputeStructuredSuccessors(ir::Function* func);
// Module for this CFG.
ir::Module* module_;
// Map from block to its structured successor blocks. See
// ComputeStructuredSuccessors() for definition.
std::unordered_map<const ir::BasicBlock*, std::vector<ir::BasicBlock*>>
block2structured_succs_;
// Extra block whose successors are all blocks with no predecessors
// in function. TODO(dnovillo): Needed?
ir::BasicBlock pseudo_entry_block_;
// Augmented CFG Exit Block. TODO(dnovillo): Needed?
ir::BasicBlock pseudo_exit_block_;
// Map from block's label id to its predecessor blocks ids
std::unordered_map<uint32_t, std::vector<uint32_t>> label2preds_;
// Map from block's label id to block.
std::unordered_map<uint32_t, ir::BasicBlock*> id2block_;
};
} // namespace opt
} // namespace spvtools
#endif // LIBSPIRV_OPT_CFG_H_