SPIRV-Tools/source/opt/inline_pass.h
Steven Perron c18c9ff6bc
Handle OpKill better (#2933)
We want to handle OpKill better.  The wrap opkill causes lots of extra
code to be generated, even when they are not needed to avoid the main
problem: OpKill cannot be found directly in a continue construct.

This change will be more selective on which functions the OpKill will be
wrapped and inlining will avoid inlining.

Fixes #2912
2019-10-04 13:05:32 -04:00

180 lines
7.0 KiB
C++

// Copyright (c) 2017 The Khronos Group Inc.
// Copyright (c) 2017 Valve Corporation
// Copyright (c) 2017 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.
#ifndef SOURCE_OPT_INLINE_PASS_H_
#define SOURCE_OPT_INLINE_PASS_H_
#include <algorithm>
#include <list>
#include <memory>
#include <set>
#include <unordered_map>
#include <vector>
#include "source/opt/decoration_manager.h"
#include "source/opt/module.h"
#include "source/opt/pass.h"
namespace spvtools {
namespace opt {
// See optimizer.hpp for documentation.
class InlinePass : public Pass {
using cbb_ptr = const BasicBlock*;
public:
virtual ~InlinePass() = default;
protected:
InlinePass();
// Add pointer to type to module and return resultId. Returns 0 if the type
// could not be created.
uint32_t AddPointerToType(uint32_t type_id, SpvStorageClass storage_class);
// Add unconditional branch to labelId to end of block block_ptr.
void AddBranch(uint32_t labelId, std::unique_ptr<BasicBlock>* block_ptr);
// Add conditional branch to end of block |block_ptr|.
void AddBranchCond(uint32_t cond_id, uint32_t true_id, uint32_t false_id,
std::unique_ptr<BasicBlock>* block_ptr);
// Add unconditional branch to labelId to end of block block_ptr.
void AddLoopMerge(uint32_t merge_id, uint32_t continue_id,
std::unique_ptr<BasicBlock>* block_ptr);
// Add store of valId to ptrId to end of block block_ptr.
void AddStore(uint32_t ptrId, uint32_t valId,
std::unique_ptr<BasicBlock>* block_ptr);
// Add load of ptrId into resultId to end of block block_ptr.
void AddLoad(uint32_t typeId, uint32_t resultId, uint32_t ptrId,
std::unique_ptr<BasicBlock>* block_ptr);
// Return new label.
std::unique_ptr<Instruction> NewLabel(uint32_t label_id);
// Returns the id for the boolean false value. Looks in the module first
// and creates it if not found. Remembers it for future calls. Returns 0 if
// the value could not be created.
uint32_t GetFalseId();
// Map callee params to caller args
void MapParams(Function* calleeFn, BasicBlock::iterator call_inst_itr,
std::unordered_map<uint32_t, uint32_t>* callee2caller);
// Clone and map callee locals. Return true if successful.
bool CloneAndMapLocals(Function* calleeFn,
std::vector<std::unique_ptr<Instruction>>* new_vars,
std::unordered_map<uint32_t, uint32_t>* callee2caller);
// Create return variable for callee clone code. The return type of
// |calleeFn| must not be void. Returns the id of the return variable if
// created. Returns 0 if the return variable could not be created.
uint32_t CreateReturnVar(Function* calleeFn,
std::vector<std::unique_ptr<Instruction>>* new_vars);
// Return true if instruction must be in the same block that its result
// is used.
bool IsSameBlockOp(const Instruction* inst) const;
// Clone operands which must be in same block as consumer instructions.
// Look in preCallSB for instructions that need cloning. Look in
// postCallSB for instructions already cloned. Add cloned instruction
// to postCallSB.
bool CloneSameBlockOps(std::unique_ptr<Instruction>* inst,
std::unordered_map<uint32_t, uint32_t>* postCallSB,
std::unordered_map<uint32_t, Instruction*>* preCallSB,
std::unique_ptr<BasicBlock>* block_ptr);
// Return in new_blocks the result of inlining the call at call_inst_itr
// within its block at call_block_itr. The block at call_block_itr can
// just be replaced with the blocks in new_blocks. Any additional branches
// are avoided. Debug instructions are cloned along with their callee
// instructions. Early returns are replaced by a store to a local return
// variable and a branch to a (created) exit block where the local variable
// is returned. Formal parameters are trivially mapped to their actual
// parameters. Note that the first block in new_blocks retains the label
// of the original calling block. Also note that if an exit block is
// created, it is the last block of new_blocks.
//
// Also return in new_vars additional OpVariable instructions required by
// and to be inserted into the caller function after the block at
// call_block_itr is replaced with new_blocks.
//
// Returns true if successful.
bool GenInlineCode(std::vector<std::unique_ptr<BasicBlock>>* new_blocks,
std::vector<std::unique_ptr<Instruction>>* new_vars,
BasicBlock::iterator call_inst_itr,
UptrVectorIterator<BasicBlock> call_block_itr);
// Return true if |inst| is a function call that can be inlined.
bool IsInlinableFunctionCall(const Instruction* inst);
// Return true if |func| does not have a return that is
// nested in a structured if, switch or loop.
bool HasNoReturnInStructuredConstruct(Function* func);
// Return true if |func| has no return in a loop. The current analysis
// requires structured control flow, so return false if control flow not
// structured ie. module is not a shader.
bool HasNoReturnInLoop(Function* func);
// Find all functions with multiple returns and no returns in loops
void AnalyzeReturns(Function* func);
// Return true if |func| is a function that can be inlined.
bool IsInlinableFunction(Function* func);
// Returns true if |func| contains an OpKill instruction.
bool ContainsKill(Function* func) const;
// Update phis in succeeding blocks to point to new last block
void UpdateSucceedingPhis(
std::vector<std::unique_ptr<BasicBlock>>& new_blocks);
// Initialize state for optimization of |module|
void InitializeInline();
// Map from function's result id to function.
std::unordered_map<uint32_t, Function*> id2function_;
// Map from block's label id to block. TODO(dnovillo): This is superfluous wrt
// CFG. It has functionality not present in CFG. Consolidate.
std::unordered_map<uint32_t, BasicBlock*> id2block_;
// Set of ids of functions with early return.
std::set<uint32_t> early_return_funcs_;
// Set of ids of functions with no returns in loop
std::set<uint32_t> no_return_in_loop_;
// Set of ids of inlinable functions
std::set<uint32_t> inlinable_;
// result id for OpConstantFalse
uint32_t false_id_;
// Set of functions that are originally called directly or indirectly from a
// continue construct.
std::unordered_set<uint32_t> funcs_called_from_continue_;
};
} // namespace opt
} // namespace spvtools
#endif // SOURCE_OPT_INLINE_PASS_H_