SPIRV-Tools/source/opt/ir_builder.h
Steven Perron 2e4563d94f
Document in the context what happens with id overflow. (#2159)
Added documentation to the ir context to indicates that TakeNextId()
returns 0 when the max id is reached.  TODOs were added to each call
sight so that we know where we have to start to handle this case.

Handle id overflow in |SplitLoopHeader|.

Handle id overflow in |GetOrCreatePreHeaderBlock|.

Handle failure to create preheader in LICM.

Part of https://github.com/KhronosGroup/SPIRV-Tools/issues/1841.
2018-12-06 09:07:00 -05:00

533 lines
22 KiB
C++

// Copyright (c) 2018 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 SOURCE_OPT_IR_BUILDER_H_
#define SOURCE_OPT_IR_BUILDER_H_
#include <limits>
#include <memory>
#include <utility>
#include <vector>
#include "source/opt/basic_block.h"
#include "source/opt/constants.h"
#include "source/opt/instruction.h"
#include "source/opt/ir_context.h"
namespace spvtools {
namespace opt {
// In SPIR-V, ids are encoded as uint16_t, this id is guaranteed to be always
// invalid.
const uint32_t kInvalidId = std::numeric_limits<uint32_t>::max();
// Helper class to abstract instruction construction and insertion.
// The instruction builder can preserve the following analyses (specified via
// the constructors):
// - Def-use analysis
// - Instruction to block analysis
class InstructionBuilder {
public:
using InsertionPointTy = BasicBlock::iterator;
// Creates an InstructionBuilder, all new instructions will be inserted before
// the instruction |insert_before|.
InstructionBuilder(
IRContext* context, Instruction* insert_before,
IRContext::Analysis preserved_analyses = IRContext::kAnalysisNone)
: InstructionBuilder(context, context->get_instr_block(insert_before),
InsertionPointTy(insert_before),
preserved_analyses) {}
// Creates an InstructionBuilder, all new instructions will be inserted at the
// end of the basic block |parent_block|.
InstructionBuilder(
IRContext* context, BasicBlock* parent_block,
IRContext::Analysis preserved_analyses = IRContext::kAnalysisNone)
: InstructionBuilder(context, parent_block, parent_block->end(),
preserved_analyses) {}
Instruction* AddNullaryOp(uint32_t type_id, SpvOp opcode) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> newUnOp(new Instruction(
GetContext(), opcode, type_id,
opcode == SpvOpReturn ? 0 : GetContext()->TakeNextId(), {}));
return AddInstruction(std::move(newUnOp));
}
Instruction* AddUnaryOp(uint32_t type_id, SpvOp opcode, uint32_t operand1) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> newUnOp(new Instruction(
GetContext(), opcode, type_id, GetContext()->TakeNextId(),
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand1}}}));
return AddInstruction(std::move(newUnOp));
}
Instruction* AddBinaryOp(uint32_t type_id, SpvOp opcode, uint32_t operand1,
uint32_t operand2) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> newBinOp(new Instruction(
GetContext(), opcode, type_id,
opcode == SpvOpStore ? 0 : GetContext()->TakeNextId(),
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand1}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand2}}}));
return AddInstruction(std::move(newBinOp));
}
Instruction* AddTernaryOp(uint32_t type_id, SpvOp opcode, uint32_t operand1,
uint32_t operand2, uint32_t operand3) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> newTernOp(new Instruction(
GetContext(), opcode, type_id, GetContext()->TakeNextId(),
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand1}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand2}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand3}}}));
return AddInstruction(std::move(newTernOp));
}
Instruction* AddQuadOp(uint32_t type_id, SpvOp opcode, uint32_t operand1,
uint32_t operand2, uint32_t operand3,
uint32_t operand4) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> newQuadOp(new Instruction(
GetContext(), opcode, type_id, GetContext()->TakeNextId(),
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand1}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand2}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand3}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand4}}}));
return AddInstruction(std::move(newQuadOp));
}
Instruction* AddIdLiteralOp(uint32_t type_id, SpvOp opcode, uint32_t operand1,
uint32_t operand2) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> newBinOp(new Instruction(
GetContext(), opcode, type_id, GetContext()->TakeNextId(),
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {operand1}},
{spv_operand_type_t::SPV_OPERAND_TYPE_LITERAL_INTEGER, {operand2}}}));
return AddInstruction(std::move(newBinOp));
}
// Creates an N-ary instruction of |opcode|.
// |typid| must be the id of the instruction's type.
// |operands| must be a sequence of operand ids.
// Use |result| for the result id if non-zero.
Instruction* AddNaryOp(uint32_t type_id, SpvOp opcode,
const std::vector<uint32_t>& operands,
uint32_t result = 0) {
std::vector<Operand> ops;
for (size_t i = 0; i < operands.size(); i++) {
ops.push_back({SPV_OPERAND_TYPE_ID, {operands[i]}});
}
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> new_inst(new Instruction(
GetContext(), opcode, type_id,
result != 0 ? result : GetContext()->TakeNextId(), ops));
return AddInstruction(std::move(new_inst));
}
// Creates a new selection merge instruction.
// The id |merge_id| is the merge basic block id.
Instruction* AddSelectionMerge(
uint32_t merge_id,
uint32_t selection_control = SpvSelectionControlMaskNone) {
std::unique_ptr<Instruction> new_branch_merge(new Instruction(
GetContext(), SpvOpSelectionMerge, 0, 0,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {merge_id}},
{spv_operand_type_t::SPV_OPERAND_TYPE_SELECTION_CONTROL,
{selection_control}}}));
return AddInstruction(std::move(new_branch_merge));
}
// Creates a new loop merge instruction.
// The id |merge_id| is the basic block id of the merge block.
// |continue_id| is the id of the continue block.
// |loop_control| are the loop control flags to be added to the instruction.
Instruction* AddLoopMerge(uint32_t merge_id, uint32_t continue_id,
uint32_t loop_control = SpvLoopControlMaskNone) {
std::unique_ptr<Instruction> new_branch_merge(new Instruction(
GetContext(), SpvOpLoopMerge, 0, 0,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {merge_id}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {continue_id}},
{spv_operand_type_t::SPV_OPERAND_TYPE_LOOP_CONTROL, {loop_control}}}));
return AddInstruction(std::move(new_branch_merge));
}
// Creates a new branch instruction to |label_id|.
// Note that the user must make sure the final basic block is
// well formed.
Instruction* AddBranch(uint32_t label_id) {
std::unique_ptr<Instruction> new_branch(new Instruction(
GetContext(), SpvOpBranch, 0, 0,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {label_id}}}));
return AddInstruction(std::move(new_branch));
}
// Creates a new conditional instruction and the associated selection merge
// instruction if requested.
// The id |cond_id| is the id of the condition instruction, must be of
// type bool.
// The id |true_id| is the id of the basic block to branch to if the condition
// is true.
// The id |false_id| is the id of the basic block to branch to if the
// condition is false.
// The id |merge_id| is the id of the merge basic block for the selection
// merge instruction. If |merge_id| equals kInvalidId then no selection merge
// instruction will be created.
// The value |selection_control| is the selection control flag for the
// selection merge instruction.
// Note that the user must make sure the final basic block is
// well formed.
Instruction* AddConditionalBranch(
uint32_t cond_id, uint32_t true_id, uint32_t false_id,
uint32_t merge_id = kInvalidId,
uint32_t selection_control = SpvSelectionControlMaskNone) {
if (merge_id != kInvalidId) {
AddSelectionMerge(merge_id, selection_control);
}
std::unique_ptr<Instruction> new_branch(new Instruction(
GetContext(), SpvOpBranchConditional, 0, 0,
{{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {cond_id}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {true_id}},
{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {false_id}}}));
return AddInstruction(std::move(new_branch));
}
// Creates a new switch instruction and the associated selection merge
// instruction if requested.
// The id |selector_id| is the id of the selector instruction, must be of
// type int.
// The id |default_id| is the id of the default basic block to branch to.
// The vector |targets| is the pair of literal/branch id.
// The id |merge_id| is the id of the merge basic block for the selection
// merge instruction. If |merge_id| equals kInvalidId then no selection merge
// instruction will be created.
// The value |selection_control| is the selection control flag for the
// selection merge instruction.
// Note that the user must make sure the final basic block is
// well formed.
Instruction* AddSwitch(
uint32_t selector_id, uint32_t default_id,
const std::vector<std::pair<Operand::OperandData, uint32_t>>& targets,
uint32_t merge_id = kInvalidId,
uint32_t selection_control = SpvSelectionControlMaskNone) {
if (merge_id != kInvalidId) {
AddSelectionMerge(merge_id, selection_control);
}
std::vector<Operand> operands;
operands.emplace_back(
Operand{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {selector_id}});
operands.emplace_back(
Operand{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {default_id}});
for (auto& target : targets) {
operands.emplace_back(
Operand{spv_operand_type_t::SPV_OPERAND_TYPE_TYPED_LITERAL_NUMBER,
target.first});
operands.emplace_back(
Operand{spv_operand_type_t::SPV_OPERAND_TYPE_ID, {target.second}});
}
std::unique_ptr<Instruction> new_switch(
new Instruction(GetContext(), SpvOpSwitch, 0, 0, operands));
return AddInstruction(std::move(new_switch));
}
// Creates a phi instruction.
// The id |type| must be the id of the phi instruction's type.
// The vector |incomings| must be a sequence of pairs of <definition id,
// parent id>.
Instruction* AddPhi(uint32_t type, const std::vector<uint32_t>& incomings,
uint32_t result = 0) {
assert(incomings.size() % 2 == 0 && "A sequence of pairs is expected");
return AddNaryOp(type, SpvOpPhi, incomings, result);
}
// Creates an addition instruction.
// The id |type| must be the id of the instruction's type, must be the same as
// |op1| and |op2| types.
// The id |op1| is the left hand side of the operation.
// The id |op2| is the right hand side of the operation.
Instruction* AddIAdd(uint32_t type, uint32_t op1, uint32_t op2) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> inst(new Instruction(
GetContext(), SpvOpIAdd, type, GetContext()->TakeNextId(),
{{SPV_OPERAND_TYPE_ID, {op1}}, {SPV_OPERAND_TYPE_ID, {op2}}}));
return AddInstruction(std::move(inst));
}
// Creates a less than instruction for unsigned integer.
// The id |op1| is the left hand side of the operation.
// The id |op2| is the right hand side of the operation.
// It is assumed that |op1| and |op2| have the same underlying type.
Instruction* AddULessThan(uint32_t op1, uint32_t op2) {
analysis::Bool bool_type;
uint32_t type = GetContext()->get_type_mgr()->GetId(&bool_type);
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> inst(new Instruction(
GetContext(), SpvOpULessThan, type, GetContext()->TakeNextId(),
{{SPV_OPERAND_TYPE_ID, {op1}}, {SPV_OPERAND_TYPE_ID, {op2}}}));
return AddInstruction(std::move(inst));
}
// Creates a less than instruction for signed integer.
// The id |op1| is the left hand side of the operation.
// The id |op2| is the right hand side of the operation.
// It is assumed that |op1| and |op2| have the same underlying type.
Instruction* AddSLessThan(uint32_t op1, uint32_t op2) {
analysis::Bool bool_type;
uint32_t type = GetContext()->get_type_mgr()->GetId(&bool_type);
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> inst(new Instruction(
GetContext(), SpvOpSLessThan, type, GetContext()->TakeNextId(),
{{SPV_OPERAND_TYPE_ID, {op1}}, {SPV_OPERAND_TYPE_ID, {op2}}}));
return AddInstruction(std::move(inst));
}
// Creates an OpILessThan or OpULessThen instruction depending on the sign of
// |op1|. The id |op1| is the left hand side of the operation. The id |op2| is
// the right hand side of the operation. It is assumed that |op1| and |op2|
// have the same underlying type.
Instruction* AddLessThan(uint32_t op1, uint32_t op2) {
Instruction* op1_insn = context_->get_def_use_mgr()->GetDef(op1);
analysis::Type* type =
GetContext()->get_type_mgr()->GetType(op1_insn->type_id());
analysis::Integer* int_type = type->AsInteger();
assert(int_type && "Operand is not of int type");
if (int_type->IsSigned())
return AddSLessThan(op1, op2);
else
return AddULessThan(op1, op2);
}
// Creates a select instruction.
// |type| must match the types of |true_value| and |false_value|. It is up to
// the caller to ensure that |cond| is a correct type (bool or vector of
// bool) for |type|.
Instruction* AddSelect(uint32_t type, uint32_t cond, uint32_t true_value,
uint32_t false_value) {
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> select(new Instruction(
GetContext(), SpvOpSelect, type, GetContext()->TakeNextId(),
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {cond}},
{SPV_OPERAND_TYPE_ID, {true_value}},
{SPV_OPERAND_TYPE_ID, {false_value}}}));
return AddInstruction(std::move(select));
}
// Adds a signed int32 constant to the binary.
// The |value| parameter is the constant value to be added.
Instruction* GetSintConstant(int32_t value) {
return GetIntConstant<int32_t>(value, true);
}
// Create a composite construct.
// |type| should be a composite type and the number of elements it has should
// match the size od |ids|.
Instruction* AddCompositeConstruct(uint32_t type,
const std::vector<uint32_t>& ids) {
std::vector<Operand> ops;
for (auto id : ids) {
ops.emplace_back(SPV_OPERAND_TYPE_ID,
std::initializer_list<uint32_t>{id});
}
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> construct(
new Instruction(GetContext(), SpvOpCompositeConstruct, type,
GetContext()->TakeNextId(), ops));
return AddInstruction(std::move(construct));
}
// Adds an unsigned int32 constant to the binary.
// The |value| parameter is the constant value to be added.
Instruction* GetUintConstant(uint32_t value) {
return GetIntConstant<uint32_t>(value, false);
}
uint32_t GetUintConstantId(uint32_t value) {
Instruction* uint_inst = GetUintConstant(value);
return uint_inst->result_id();
}
uint32_t GetNullId(uint32_t type_id) {
analysis::TypeManager* type_mgr = GetContext()->get_type_mgr();
analysis::ConstantManager* const_mgr = GetContext()->get_constant_mgr();
const analysis::Type* type = type_mgr->GetType(type_id);
const analysis::Constant* null_const = const_mgr->GetConstant(type, {});
Instruction* null_inst =
const_mgr->GetDefiningInstruction(null_const, type_id);
return null_inst->result_id();
}
// Adds either a signed or unsigned 32 bit integer constant to the binary
// depedning on the |sign|. If |sign| is true then the value is added as a
// signed constant otherwise as an unsigned constant. If |sign| is false the
// value must not be a negative number.
template <typename T>
Instruction* GetIntConstant(T value, bool sign) {
// Assert that we are not trying to store a negative number in an unsigned
// type.
if (!sign)
assert(value >= 0 &&
"Trying to add a signed integer with an unsigned type!");
analysis::Integer int_type{32, sign};
// Get or create the integer type. This rebuilds the type and manages the
// memory for the rebuilt type.
uint32_t type_id =
GetContext()->get_type_mgr()->GetTypeInstruction(&int_type);
// Get the memory managed type so that it is safe to be stored by
// GetConstant.
analysis::Type* rebuilt_type =
GetContext()->get_type_mgr()->GetType(type_id);
// Even if the value is negative we need to pass the bit pattern as a
// uint32_t to GetConstant.
uint32_t word = value;
// Create the constant value.
const analysis::Constant* constant =
GetContext()->get_constant_mgr()->GetConstant(rebuilt_type, {word});
// Create the OpConstant instruction using the type and the value.
return GetContext()->get_constant_mgr()->GetDefiningInstruction(constant);
}
Instruction* AddCompositeExtract(uint32_t type, uint32_t id_of_composite,
const std::vector<uint32_t>& index_list) {
std::vector<Operand> operands;
operands.push_back({SPV_OPERAND_TYPE_ID, {id_of_composite}});
for (uint32_t index : index_list) {
operands.push_back({SPV_OPERAND_TYPE_LITERAL_INTEGER, {index}});
}
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> new_inst(
new Instruction(GetContext(), SpvOpCompositeExtract, type,
GetContext()->TakeNextId(), operands));
return AddInstruction(std::move(new_inst));
}
// Creates an unreachable instruction.
Instruction* AddUnreachable() {
std::unique_ptr<Instruction> select(
new Instruction(GetContext(), SpvOpUnreachable, 0, 0,
std::initializer_list<Operand>{}));
return AddInstruction(std::move(select));
}
Instruction* AddAccessChain(uint32_t type_id, uint32_t base_ptr_id,
std::vector<uint32_t> ids) {
std::vector<Operand> operands;
operands.push_back({SPV_OPERAND_TYPE_ID, {base_ptr_id}});
for (uint32_t index_id : ids) {
operands.push_back({SPV_OPERAND_TYPE_ID, {index_id}});
}
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> new_inst(
new Instruction(GetContext(), SpvOpAccessChain, type_id,
GetContext()->TakeNextId(), operands));
return AddInstruction(std::move(new_inst));
}
Instruction* AddLoad(uint32_t type_id, uint32_t base_ptr_id) {
std::vector<Operand> operands;
operands.push_back({SPV_OPERAND_TYPE_ID, {base_ptr_id}});
// TODO(1841): Handle id overflow.
std::unique_ptr<Instruction> new_inst(
new Instruction(GetContext(), SpvOpLoad, type_id,
GetContext()->TakeNextId(), operands));
return AddInstruction(std::move(new_inst));
}
// Inserts the new instruction before the insertion point.
Instruction* AddInstruction(std::unique_ptr<Instruction>&& insn) {
Instruction* insn_ptr = &*insert_before_.InsertBefore(std::move(insn));
UpdateInstrToBlockMapping(insn_ptr);
UpdateDefUseMgr(insn_ptr);
return insn_ptr;
}
// Returns the insertion point iterator.
InsertionPointTy GetInsertPoint() { return insert_before_; }
// Change the insertion point to insert before the instruction
// |insert_before|.
void SetInsertPoint(Instruction* insert_before) {
parent_ = context_->get_instr_block(insert_before);
insert_before_ = InsertionPointTy(insert_before);
}
// Change the insertion point to insert at the end of the basic block
// |parent_block|.
void SetInsertPoint(BasicBlock* parent_block) {
parent_ = parent_block;
insert_before_ = parent_block->end();
}
// Returns the context which instructions are constructed for.
IRContext* GetContext() const { return context_; }
// Returns the set of preserved analyses.
inline IRContext::Analysis GetPreservedAnalysis() const {
return preserved_analyses_;
}
private:
InstructionBuilder(IRContext* context, BasicBlock* parent,
InsertionPointTy insert_before,
IRContext::Analysis preserved_analyses)
: context_(context),
parent_(parent),
insert_before_(insert_before),
preserved_analyses_(preserved_analyses) {
assert(!(preserved_analyses_ & ~(IRContext::kAnalysisDefUse |
IRContext::kAnalysisInstrToBlockMapping)));
}
// Returns true if the users requested to update |analysis|.
inline bool IsAnalysisUpdateRequested(IRContext::Analysis analysis) const {
return preserved_analyses_ & analysis;
}
// Updates the def/use manager if the user requested it. If he did not request
// an update, this function does nothing.
inline void UpdateDefUseMgr(Instruction* insn) {
if (IsAnalysisUpdateRequested(IRContext::kAnalysisDefUse))
GetContext()->get_def_use_mgr()->AnalyzeInstDefUse(insn);
}
// Updates the instruction to block analysis if the user requested it. If he
// did not request an update, this function does nothing.
inline void UpdateInstrToBlockMapping(Instruction* insn) {
if (IsAnalysisUpdateRequested(IRContext::kAnalysisInstrToBlockMapping) &&
parent_)
GetContext()->set_instr_block(insn, parent_);
}
IRContext* context_;
BasicBlock* parent_;
InsertionPointTy insert_before_;
const IRContext::Analysis preserved_analyses_;
};
} // namespace opt
} // namespace spvtools
#endif // SOURCE_OPT_IR_BUILDER_H_