2018-04-11 05:44:28 +03:00
|
|
|
// Copyright (c) 2018 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.
|
|
|
|
|
2018-09-03 07:14:20 +03:00
|
|
|
#ifndef SOURCE_OPT_CONST_FOLDING_RULES_H_
|
|
|
|
#define SOURCE_OPT_CONST_FOLDING_RULES_H_
|
2018-04-11 05:44:28 +03:00
|
|
|
|
2018-09-03 07:14:20 +03:00
|
|
|
#include <unordered_map>
|
2018-04-11 05:44:28 +03:00
|
|
|
#include <vector>
|
|
|
|
|
2018-09-03 07:14:20 +03:00
|
|
|
#include "source/opt/constants.h"
|
2018-04-11 05:44:28 +03:00
|
|
|
|
|
|
|
namespace spvtools {
|
|
|
|
namespace opt {
|
|
|
|
|
|
|
|
// Constant Folding Rules:
|
|
|
|
//
|
|
|
|
// The folding mechanism is built around the concept of a |ConstantFoldingRule|.
|
|
|
|
// A constant folding rule is a function that implements a method of simplifying
|
|
|
|
// an instruction to a constant.
|
|
|
|
//
|
|
|
|
// The inputs to a folding rule are:
|
|
|
|
// |inst| - the instruction to be simplified.
|
|
|
|
// |constants| - if an in-operands is an id of a constant, then the
|
|
|
|
// corresponding value in |constants| contains that
|
|
|
|
// constant value. Otherwise, the corresponding entry in
|
|
|
|
// |constants| is |nullptr|.
|
|
|
|
//
|
|
|
|
// A constant folding rule returns a pointer to an Constant if |inst| can be
|
|
|
|
// simplified using this rule. Otherwise, it returns |nullptr|.
|
|
|
|
//
|
|
|
|
// See const_folding_rules.cpp for examples on how to write a constant folding
|
|
|
|
// rule.
|
|
|
|
//
|
|
|
|
// Be sure to add new constant folding rules to the table of constant folding
|
|
|
|
// rules in the constructor for ConstantFoldingRules. The new rule should be
|
|
|
|
// added to the list for every opcode that it applies to. Note that earlier
|
|
|
|
// rules in the list are given priority. That is, if an earlier rule is able to
|
|
|
|
// fold an instruction, the later rules will not be attempted.
|
|
|
|
|
|
|
|
using ConstantFoldingRule = std::function<const analysis::Constant*(
|
2018-09-03 07:14:20 +03:00
|
|
|
IRContext* ctx, Instruction* inst,
|
2018-04-11 05:44:28 +03:00
|
|
|
const std::vector<const analysis::Constant*>& constants)>;
|
|
|
|
|
|
|
|
class ConstantFoldingRules {
|
|
|
|
public:
|
|
|
|
ConstantFoldingRules();
|
|
|
|
|
|
|
|
// Returns true if there is at least 1 folding rule for |opcode|.
|
|
|
|
bool HasFoldingRule(SpvOp opcode) const { return rules_.count(opcode); }
|
|
|
|
|
|
|
|
// Returns an vector of constant folding rules for |opcode|.
|
|
|
|
const std::vector<ConstantFoldingRule>& GetRulesForOpcode(
|
|
|
|
SpvOp opcode) const {
|
|
|
|
auto it = rules_.find(opcode);
|
|
|
|
if (it != rules_.end()) {
|
|
|
|
return it->second;
|
|
|
|
}
|
|
|
|
return empty_vector_;
|
|
|
|
}
|
|
|
|
|
|
|
|
private:
|
|
|
|
std::unordered_map<uint32_t, std::vector<ConstantFoldingRule>> rules_;
|
|
|
|
std::vector<ConstantFoldingRule> empty_vector_;
|
|
|
|
};
|
|
|
|
|
|
|
|
} // namespace opt
|
|
|
|
} // namespace spvtools
|
|
|
|
|
2018-09-03 07:14:20 +03:00
|
|
|
#endif // SOURCE_OPT_CONST_FOLDING_RULES_H_
|