SPIRV-Tools/tools/reduce/reduce.cpp
Alastair Donaldson 34c5ac614c
Fixes #2358. Added to the reducer the ability to remove a function t… (#2361)
* Fixes #2358.  Added to the reducer the ability to remove a function that is not directly called.  Factored out some code from the optimizer to help with this.
2019-02-08 16:20:29 +00:00

270 lines
9.5 KiB
C++

// 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.
#include <cassert>
#include <cerrno>
#include <cstring>
#include <functional>
#include "source/opt/build_module.h"
#include "source/opt/ir_context.h"
#include "source/opt/log.h"
#include "source/reduce/merge_blocks_reduction_opportunity_finder.h"
#include "source/reduce/operand_to_const_reduction_opportunity_finder.h"
#include "source/reduce/operand_to_dominating_id_reduction_opportunity_finder.h"
#include "source/reduce/operand_to_undef_reduction_opportunity_finder.h"
#include "source/reduce/reducer.h"
#include "source/reduce/remove_function_reduction_opportunity_finder.h"
#include "source/reduce/remove_opname_instruction_reduction_opportunity_finder.h"
#include "source/reduce/remove_unreferenced_instruction_reduction_opportunity_finder.h"
#include "source/reduce/structured_loop_to_selection_reduction_opportunity_finder.h"
#include "source/spirv_reducer_options.h"
#include "source/util/make_unique.h"
#include "source/util/string_utils.h"
#include "spirv-tools/libspirv.hpp"
#include "tools/io.h"
#include "tools/util/cli_consumer.h"
using namespace spvtools::reduce;
namespace {
using ErrorOrInt = std::pair<std::string, int>;
// Check that the std::system function can actually be used.
bool CheckExecuteCommand() {
int res = std::system(nullptr);
return res != 0;
}
// Execute a command using the shell.
// Returns true if and only if the command's exit status was 0.
bool ExecuteCommand(const std::string& command) {
errno = 0;
int status = std::system(command.c_str());
assert(errno == 0 && "failed to execute command");
// The result returned by 'system' is implementation-defined, but is
// usually the case that the returned value is 0 when the command's exit
// code was 0. We are assuming that here, and that's all we depend on.
return status == 0;
}
// Status and actions to perform after parsing command-line arguments.
enum ReduceActions { REDUCE_CONTINUE, REDUCE_STOP };
struct ReduceStatus {
ReduceActions action;
int code;
};
void PrintUsage(const char* program) {
// NOTE: Please maintain flags in lexicographical order.
printf(
R"(%s - Reduce a SPIR-V binary file with respect to a user-provided
interestingness test.
USAGE: %s [options] <input> <interestingness-test>
The SPIR-V binary is read from <input>.
Whether a binary is interesting is determined by <interestingness-test>, which
should be the path to a script.
* The script must be executable.
* The script should take the path to a SPIR-V binary file (.spv) as its single
argument, and exit with code 0 if and only if the binary file is
interesting.
* Example: an interestingness test for reducing a SPIR-V binary file that
causes tool "foo" to exit with error code 1 and print "Fatal error: bar" to
standard error should:
- invoke "foo" on the binary passed as the script argument;
- capture the return code and standard error from "bar";
- exit with code 0 if and only if the return code of "foo" was 1 and the
standard error from "bar" contained "Fatal error: bar".
* The reducer does not place a time limit on how long the interestingness test
takes to run, so it is advisable to use per-command timeouts inside the
script when invoking SPIR-V-processing tools (such as "foo" in the above
example).
NOTE: The reducer is a work in progress.
Options (in lexicographical order):
-h, --help
Print this help.
--step-limit
32-bit unsigned integer specifying maximum number of steps the
reducer will take before giving up.
--version
Display reducer version information.
)",
program, program);
}
// Message consumer for this tool. Used to emit diagnostics during
// initialization and setup. Note that |source| and |position| are irrelevant
// here because we are still not processing a SPIR-V input file.
void ReduceDiagnostic(spv_message_level_t level, const char* /*source*/,
const spv_position_t& /*position*/, const char* message) {
if (level == SPV_MSG_ERROR) {
fprintf(stderr, "error: ");
}
fprintf(stderr, "%s\n", message);
}
ReduceStatus ParseFlags(int argc, const char** argv, const char** in_file,
const char** interestingness_test,
spvtools::ReducerOptions* reducer_options) {
uint32_t positional_arg_index = 0;
for (int argi = 1; argi < argc; ++argi) {
const char* cur_arg = argv[argi];
if ('-' == cur_arg[0]) {
if (0 == strcmp(cur_arg, "--version")) {
spvtools::Logf(ReduceDiagnostic, SPV_MSG_INFO, nullptr, {}, "%s\n",
spvSoftwareVersionDetailsString());
return {REDUCE_STOP, 0};
} else if (0 == strcmp(cur_arg, "--help") || 0 == strcmp(cur_arg, "-h")) {
PrintUsage(argv[0]);
return {REDUCE_STOP, 0};
} else if ('\0' == cur_arg[1]) {
// We do not support reduction from standard input. We could support
// this if there was a compelling use case.
PrintUsage(argv[0]);
return {REDUCE_STOP, 0};
} else if (0 == strncmp(cur_arg,
"--step-limit=", sizeof("--step-limit=") - 1)) {
const auto split_flag = spvtools::utils::SplitFlagArgs(cur_arg);
char* end = nullptr;
errno = 0;
const auto step_limit =
static_cast<uint32_t>(strtol(split_flag.second.c_str(), &end, 10));
assert(end != split_flag.second.c_str() && errno == 0);
reducer_options->set_step_limit(step_limit);
}
} else if (positional_arg_index == 0) {
// Input file name
assert(!*in_file);
*in_file = cur_arg;
positional_arg_index++;
} else if (positional_arg_index == 1) {
assert(!*interestingness_test);
*interestingness_test = cur_arg;
positional_arg_index++;
} else {
spvtools::Error(ReduceDiagnostic, nullptr, {},
"Too many positional arguments specified");
return {REDUCE_STOP, 1};
}
}
if (!*in_file) {
spvtools::Error(ReduceDiagnostic, nullptr, {}, "No input file specified");
return {REDUCE_STOP, 1};
}
if (!*interestingness_test) {
spvtools::Error(ReduceDiagnostic, nullptr, {},
"No interestingness test specified");
return {REDUCE_STOP, 1};
}
return {REDUCE_CONTINUE, 0};
}
} // namespace
const auto kDefaultEnvironment = SPV_ENV_UNIVERSAL_1_3;
int main(int argc, const char** argv) {
const char* in_file = nullptr;
const char* interestingness_test = nullptr;
spv_target_env target_env = kDefaultEnvironment;
spvtools::ReducerOptions reducer_options;
ReduceStatus status =
ParseFlags(argc, argv, &in_file, &interestingness_test, &reducer_options);
if (status.action == REDUCE_STOP) {
return status.code;
}
if (!CheckExecuteCommand()) {
std::cerr << "could not find shell interpreter for executing a command"
<< std::endl;
return 2;
}
Reducer reducer(target_env);
reducer.SetInterestingnessFunction(
[interestingness_test](std::vector<uint32_t> binary,
uint32_t reductions_applied) -> bool {
std::stringstream ss;
ss << "temp_" << std::setw(4) << std::setfill('0') << reductions_applied
<< ".spv";
const auto spv_file = ss.str();
const std::string command =
std::string(interestingness_test) + " " + spv_file;
auto write_file_succeeded =
WriteFile(spv_file.c_str(), "wb", &binary[0], binary.size());
(void)(write_file_succeeded);
assert(write_file_succeeded);
return ExecuteCommand(command);
});
reducer.AddReductionPass(
spvtools::MakeUnique<
RemoveOpNameInstructionReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<OperandToUndefReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<OperandToConstReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<OperandToDominatingIdReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<
RemoveUnreferencedInstructionReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<
StructuredLoopToSelectionReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<MergeBlocksReductionOpportunityFinder>());
reducer.AddReductionPass(
spvtools::MakeUnique<RemoveFunctionReductionOpportunityFinder>());
reducer.SetMessageConsumer(spvtools::utils::CLIMessageConsumer);
std::vector<uint32_t> binary_in;
if (!ReadFile<uint32_t>(in_file, "rb", &binary_in)) {
return 1;
}
std::vector<uint32_t> binary_out;
const auto reduction_status =
reducer.Run(std::move(binary_in), &binary_out, reducer_options);
if (reduction_status ==
Reducer::ReductionResultStatus::kInitialStateNotInteresting ||
!WriteFile<uint32_t>("_reduced_final.spv", "wb", binary_out.data(),
binary_out.size())) {
return 1;
}
return 0;
}