SPIRV-Tools/source/opt/instrument_pass.h
2018-11-12 15:11:32 -05:00

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// Copyright (c) 2018 The Khronos Group Inc.
// Copyright (c) 2018 Valve Corporation
// Copyright (c) 2018 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 LIBSPIRV_OPT_INSTRUMENT_PASS_H_
#define LIBSPIRV_OPT_INSTRUMENT_PASS_H_
#include <list>
#include <memory>
#include <vector>
#include "source/opt/ir_builder.h"
#include "source/opt/pass.h"
#include "spirv-tools/instrument.hpp"
// This is a base class to assist in the creation of passes which instrument
// shader modules. More specifically, passes which replace instructions with a
// larger and more capable set of instructions. Commonly, these new
// instructions will add testing of operands and execute different
// instructions depending on the outcome, including outputting of debug
// information into a buffer created especially for that purpose.
//
// This class contains helper functions to create an InstProcessFunction,
// which is the heart of any derived class implementing a specific
// instrumentation pass. It takes an instruction as an argument, decides
// if it should be instrumented, and generates code to replace it. This class
// also supplies function InstProcessEntryPointCallTree which applies the
// InstProcessFunction to every reachable instruction in a module and replaces
// the instruction with new instructions if generated.
//
// Chief among the helper functions are output code generation functions,
// used to generate code in the shader which writes data to output buffers
// associated with that validation. Currently one such function,
// GenDebugStreamWrite, exists. Other such functions may be added in the
// future. Each is accompanied by documentation describing the format of
// its output buffer.
//
// A validation pass may read or write multiple buffers. All such buffers
// are located in a single debug descriptor set whose index is passed at the
// creation of the instrumentation pass. The bindings of the buffers used by
// a validation pass are permanantly assigned and fixed and documented by
// the kDebugOutput* static consts.
namespace spvtools {
namespace opt {
// Validation Ids
// These are used to identify the general validation being done and map to
// its output buffers.
static const uint32_t kInstValidationIdBindless = 0;
class InstrumentPass : public Pass {
using cbb_ptr = const BasicBlock*;
public:
using InstProcessFunction = std::function<void(
BasicBlock::iterator, UptrVectorIterator<BasicBlock>, uint32_t, uint32_t,
std::vector<std::unique_ptr<BasicBlock>>*)>;
~InstrumentPass() override = default;
IRContext::Analysis GetPreservedAnalyses() override {
return IRContext::kAnalysisDefUse |
IRContext::kAnalysisInstrToBlockMapping |
IRContext::kAnalysisDecorations | IRContext::kAnalysisCombinators |
IRContext::kAnalysisNameMap | IRContext::kAnalysisBuiltinVarId;
}
protected:
// Create instrumentation pass which utilizes descriptor set |desc_set|
// for debug input and output buffers and writes |shader_id| into debug
// output records.
InstrumentPass(uint32_t desc_set, uint32_t shader_id, uint32_t validation_id)
: Pass(),
desc_set_(desc_set),
shader_id_(shader_id),
validation_id_(validation_id) {}
// Initialize state for instrumentation of module by |validation_id|.
void InitializeInstrument();
// Call |pfn| on all instructions in all functions in the call tree of the
// entry points in |module|. If code is generated for an instruction, replace
// the instruction's block with the new blocks that are generated. Continue
// processing at the top of the last new block.
bool InstProcessEntryPointCallTree(InstProcessFunction& pfn);
// Move all code in |ref_block_itr| preceding the instruction |ref_inst_itr|
// to be instrumented into block |new_blk_ptr|.
void MovePreludeCode(BasicBlock::iterator ref_inst_itr,
UptrVectorIterator<BasicBlock> ref_block_itr,
std::unique_ptr<BasicBlock>* new_blk_ptr);
// Move all code in |ref_block_itr| succeeding the instruction |ref_inst_itr|
// to be instrumented into block |new_blk_ptr|.
void MovePostludeCode(UptrVectorIterator<BasicBlock> ref_block_itr,
std::unique_ptr<BasicBlock>* new_blk_ptr);
// Generate instructions in |builder| which will atomically fetch and
// increment the size of the debug output buffer stream of the current
// validation and write a record to the end of the stream, if enough space
// in the buffer remains. The record will contain the index of the function
// and instruction within that function |func_idx, instruction_idx| which
// generated the record. It will also contain additional information to
// identify the instance of the shader, depending on the stage |stage_idx|
// of the shader. Finally, the record will contain validation-specific
// data contained in |validation_ids| which will identify the validation
// error as well as the values involved in the error.
//
// The output buffer binding written to by the code generated by the function
// is determined by the validation id specified when each specific
// instrumentation pass is created.
//
// The output buffer is a sequence of 32-bit values with the following
// format (where all elements are unsigned 32-bit unless otherwise noted):
//
// Size
// Record0
// Record1
// Record2
// ...
//
// Size is the number of 32-bit values that have been written or
// attempted to be written to the output buffer, excluding the Size. It is
// initialized to 0. If the size of attempts to write the buffer exceeds
// the actual size of the buffer, it is possible that this field can exceed
// the actual size of the buffer.
//
// Each Record* is a variable-length sequence of 32-bit values with the
// following format defined using static const offsets in the .cpp file:
//
// Record Size
// Shader ID
// Instruction Index
// Stage
// Stage-specific Word 0
// Stage-specific Word 1
// Validation Error Code
// Validation-specific Word 0
// Validation-specific Word 1
// Validation-specific Word 2
// ...
//
// Each record consists of three subsections: members common across all
// validation, members specific to the stage, and members specific to a
// validation.
//
// The Record Size is the number of 32-bit words in the record, including
// the Record Size word.
//
// Shader ID is a value that identifies which shader has generated the
// validation error. It is passed when the instrumentation pass is created.
//
// The Instruction Index is the position of the instruction within the
// SPIR-V file which is in error.
//
// The Stage is the pipeline stage which has generated the error as defined
// by the SpvExecutionModel_ enumeration. This is used to interpret the
// following Stage-specific words.
//
// The Stage-specific Words identify which invocation of the shader generated
// the error. Every stage will write two words, although in some cases the
// second word is unused and so zero is written. Vertex shaders will write
// the Vertex and Instance ID. Fragment shaders will write FragCoord.xy.
// Compute shaders will write the Global Invocation ID and zero (unused).
// Both tesselation shaders will write the Invocation Id and zero (unused).
// The geometry shader will write the Primitive ID and Invocation ID.
//
// The Validation Error Code specifies the exact error which has occurred.
// These are enumerated with the kInstError* static consts. This allows
// multiple validation layers to use the same, single output buffer.
//
// The Validation-specific Words are a validation-specific number of 32-bit
// words which give further information on the validation error that
// occurred. These are documented further in each file containing the
// validation-specific class which derives from this base class.
//
// Because the code that is generated checks against the size of the buffer
// before writing, the size of the debug out buffer can be used by the
// validation layer to control the number of error records that are written.
void GenDebugStreamWrite(uint32_t instruction_idx, uint32_t stage_idx,
const std::vector<uint32_t>& validation_ids,
InstructionBuilder* builder);
// Generate code to cast |value_id| to unsigned, if needed. Return
// an id to the unsigned equivalent.
uint32_t GenUintCastCode(uint32_t value_id, InstructionBuilder* builder);
// Return new label.
std::unique_ptr<Instruction> NewLabel(uint32_t label_id);
// Return id for 32-bit unsigned type
uint32_t GetUintId();
// Return id for 32-bit unsigned type
uint32_t GetBoolId();
// Return id for void type
uint32_t GetVoidId();
// Return id for output buffer uint type
uint32_t GetOutputBufferUintPtrId();
// Return binding for output buffer for current validation.
uint32_t GetOutputBufferBinding();
// Return id for debug output buffer
uint32_t GetOutputBufferId();
// Return id for v4float type
uint32_t GetVec4FloatId();
// Return id for v4uint type
uint32_t GetVec4UintId();
// Return id for output function. Define if it doesn't exist with
// |val_spec_arg_cnt| validation-specific uint32 arguments.
uint32_t GetStreamWriteFunctionId(uint32_t stage_idx,
uint32_t val_spec_param_cnt);
// Apply instrumentation function |pfn| to every instruction in |func|.
// If code is generated for an instruction, replace the instruction's
// block with the new blocks that are generated. Continue processing at the
// top of the last new block.
bool InstrumentFunction(Function* func, uint32_t stage_idx,
InstProcessFunction& pfn);
// Call |pfn| on all functions in the call tree of the function
// ids in |roots|.
bool InstProcessCallTreeFromRoots(InstProcessFunction& pfn,
std::queue<uint32_t>* roots,
uint32_t stage_idx);
// Gen code into |builder| to write |field_value_id| into debug output
// buffer at |base_offset_id| + |field_offset|.
void GenDebugOutputFieldCode(uint32_t base_offset_id, uint32_t field_offset,
uint32_t field_value_id,
InstructionBuilder* builder);
// Generate instructions into |builder| which will write the members
// of the debug output record common for all stages and validations at
// |base_off|.
void GenCommonStreamWriteCode(uint32_t record_sz, uint32_t instruction_idx,
uint32_t stage_idx, uint32_t base_off,
InstructionBuilder* builder);
// Generate instructions into |builder| which will write
// |uint_frag_coord_id| at |component| of the record at |base_offset_id| of
// the debug output buffer .
void GenFragCoordEltDebugOutputCode(uint32_t base_offset_id,
uint32_t uint_frag_coord_id,
uint32_t component,
InstructionBuilder* builder);
// Generate instructions into |builder| which will load the uint |builtin_id|
// and write it into the debug output buffer at |base_off| + |builtin_off|.
void GenBuiltinOutputCode(uint32_t builtin_id, uint32_t builtin_off,
uint32_t base_off, InstructionBuilder* builder);
// Generate instructions into |builder| which will write a uint null into
// the debug output buffer at |base_off| + |builtin_off|.
void GenUintNullOutputCode(uint32_t field_off, uint32_t base_off,
InstructionBuilder* builder);
// Generate instructions into |builder| which will write the |stage_idx|-
// specific members of the debug output stream at |base_off|.
void GenStageStreamWriteCode(uint32_t stage_idx, uint32_t base_off,
InstructionBuilder* builder);
// 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 same_blk_pre for instructions that need cloning. Look in
// same_blk_post for instructions already cloned. Add cloned instruction
// to same_blk_post.
void CloneSameBlockOps(
std::unique_ptr<Instruction>* inst,
std::unordered_map<uint32_t, uint32_t>* same_blk_post,
std::unordered_map<uint32_t, Instruction*>* same_blk_pre,
std::unique_ptr<BasicBlock>* block_ptr);
// Update phis in succeeding blocks to point to new last block
void UpdateSucceedingPhis(
std::vector<std::unique_ptr<BasicBlock>>& new_blocks);
// Debug descriptor set index
uint32_t desc_set_;
// Shader module ID written into output record
uint32_t shader_id_;
// Map from function id to function pointer.
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_;
// Map from function's position index to the offset of its first instruction
std::unordered_map<uint32_t, uint32_t> funcIdx2offset_;
// result id for OpConstantFalse
uint32_t validation_id_;
// id for output buffer variable
uint32_t output_buffer_id_;
// type id for output buffer element
uint32_t output_buffer_uint_ptr_id_;
// id for debug output function
uint32_t output_func_id_;
// param count for output function
uint32_t output_func_param_cnt_;
// id for v4float type
uint32_t v4float_id_;
// id for v4float type
uint32_t v4uint_id_;
// id for 32-bit unsigned type
uint32_t uint_id_;
// id for bool type
uint32_t bool_id_;
// id for void type
uint32_t void_id_;
// Pre-instrumentation same-block insts
std::unordered_map<uint32_t, Instruction*> same_block_pre_;
// Post-instrumentation same-block op ids
std::unordered_map<uint32_t, uint32_t> same_block_post_;
};
} // namespace opt
} // namespace spvtools
#endif // LIBSPIRV_OPT_INSTRUMENT_PASS_H_