// Copyright (c) 2016 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.
#include <algorithm>
#include <cassert>
#include <cstring>
#include <fstream>
#include <iostream>
#include <memory>
#include <sstream>
#include <string>
#include <vector>
#include "source/opt/log.h"
#include "source/spirv_target_env.h"
#include "source/util/string_utils.h"
#include "spirv-tools/libspirv.hpp"
#include "spirv-tools/optimizer.hpp"
#include "tools/io.h"
#include "tools/util/cli_consumer.h"
namespace {
// Status and actions to perform after parsing command-line arguments.
enum OptActions { OPT_CONTINUE, OPT_STOP };
struct OptStatus {
OptActions action;
int code;
};
// 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 opt_diagnostic(spv_message_level_t level, const char* /*source*/,
const spv_position_t& /*positon*/, const char* message) {
if (level == SPV_MSG_ERROR) {
fprintf(stderr, "error: ");
}
fprintf(stderr, "%s\n", message);
}
std::string GetListOfPassesAsString(const spvtools::Optimizer& optimizer) {
std::stringstream ss;
for (const auto& name : optimizer.GetPassNames()) {
ss << "\n\t\t" << name;
}
return ss.str();
}
const auto kDefaultEnvironment = SPV_ENV_UNIVERSAL_1_3;
std::string GetLegalizationPasses() {
spvtools::Optimizer optimizer(kDefaultEnvironment);
optimizer.RegisterLegalizationPasses();
return GetListOfPassesAsString(optimizer);
}
std::string GetOptimizationPasses() {
spvtools::Optimizer optimizer(kDefaultEnvironment);
optimizer.RegisterPerformancePasses();
return GetListOfPassesAsString(optimizer);
}
std::string GetSizePasses() {
spvtools::Optimizer optimizer(kDefaultEnvironment);
optimizer.RegisterSizePasses();
return GetListOfPassesAsString(optimizer);
}
std::string GetWebGPUPasses() {
spvtools::Optimizer optimizer(SPV_ENV_WEBGPU_0);
optimizer.RegisterWebGPUPasses();
return GetListOfPassesAsString(optimizer);
}
void PrintUsage(const char* program) {
// NOTE: Please maintain flags in lexicographical order.
printf(
R"(%s - Optimize a SPIR-V binary file.
USAGE: %s [options] [<input>] -o <output>
The SPIR-V binary is read from <input>. If no file is specified,
or if <input> is "-", then the binary is read from standard input.
if <output> is "-", then the optimized output is written to
standard output.
NOTE: The optimizer is a work in progress.
Options (in lexicographical order):
--ccp
Apply the conditional constant propagation transform. This will
propagate constant values throughout the program, and simplify
expressions and conditional jumps with known predicate
values. Performed on entry point call tree functions and
exported functions.
--cfg-cleanup
Cleanup the control flow graph. This will remove any unnecessary
code from the CFG like unreachable code. Performed on entry
point call tree functions and exported functions.
--combine-access-chains
Combines chained access chains to produce a single instruction
where possible.
--compact-ids
Remap result ids to a compact range starting from %%1 and without
any gaps.
--convert-local-access-chains
Convert constant index access chain loads/stores into
equivalent load/stores with inserts and extracts. Performed
on function scope variables referenced only with load, store,
and constant index access chains in entry point call tree
functions.
--copy-propagate-arrays
Does propagation of memory references when an array is a copy of
another. It will only propagate an array if the source is never
written to, and the only store to the target is the copy.
--eliminate-common-uniform
Perform load/load elimination for duplicate uniform values.
Converts any constant index access chain uniform loads into
its equivalent load and extract. Some loads will be moved
to facilitate sharing. Performed only on entry point
call tree functions.
--eliminate-dead-branches
Convert conditional branches with constant condition to the
indicated unconditional brranch. Delete all resulting dead
code. Performed only on entry point call tree functions.
--eliminate-dead-code-aggressive
Delete instructions which do not contribute to a function's
output. Performed only on entry point call tree functions.
--eliminate-dead-const
Eliminate dead constants.
--eliminate-dead-functions
Deletes functions that cannot be reached from entry points or
exported functions.
--eliminate-dead-inserts
Deletes unreferenced inserts into composites, most notably
unused stores to vector components, that are not removed by
aggressive dead code elimination.
--eliminate-dead-variables
Deletes module scope variables that are not referenced.
--eliminate-insert-extract
DEPRECATED. This pass has been replaced by the simplification
pass, and that pass will be run instead.
See --simplify-instructions.
--eliminate-local-multi-store
Replace stores and loads of function scope variables that are
stored multiple times. Performed on variables referenceed only
with loads and stores. Performed only on entry point call tree
functions.
--eliminate-local-single-block
Perform single-block store/load and load/load elimination.
Performed only on function scope variables in entry point
call tree functions.
--eliminate-local-single-store
Replace stores and loads of function scope variables that are
only stored once. Performed on variables referenceed only with
loads and stores. Performed only on entry point call tree
functions.
--flatten-decorations
Replace decoration groups with repeated OpDecorate and
OpMemberDecorate instructions.
--fold-spec-const-op-composite
Fold the spec constants defined by OpSpecConstantOp or
OpSpecConstantComposite instructions to front-end constants
when possible.
--freeze-spec-const
Freeze the values of specialization constants to their default
values.
--if-conversion
Convert if-then-else like assignments into OpSelect.
--inline-entry-points-exhaustive
Exhaustively inline all function calls in entry point call tree
functions. Currently does not inline calls to functions with
early return in a loop.
--legalize-hlsl
Runs a series of optimizations that attempts to take SPIR-V
generated by an HLSL front-end and generates legal Vulkan SPIR-V.
The optimizations are:
%s
Note this does not guarantee legal code. This option passes the
option --relax-logical-pointer to the validator.
--local-redundancy-elimination
Looks for instructions in the same basic block that compute the
same value, and deletes the redundant ones.
--loop-fission
Splits any top level loops in which the register pressure has
exceeded a given threshold. The threshold must follow the use of
this flag and must be a positive integer value.
--loop-fusion
Identifies adjacent loops with the same lower and upper bound.
If this is legal, then merge the loops into a single loop.
Includes heuristics to ensure it does not increase number of
registers too much, while reducing the number of loads from
memory. Takes an additional positive integer argument to set
the maximum number of registers.
--loop-invariant-code-motion
Identifies code in loops that has the same value for every
iteration of the loop, and move it to the loop pre-header.
--loop-unroll
Fully unrolls loops marked with the Unroll flag
--loop-unroll-partial
Partially unrolls loops marked with the Unroll flag. Takes an
additional non-0 integer argument to set the unroll factor, or
how many times a loop body should be duplicated
--loop-peeling
Execute few first (respectively last) iterations before
(respectively after) the loop if it can elide some branches.
--loop-peeling-threshold
Takes a non-0 integer argument to set the loop peeling code size
growth threshold. The threshold prevents the loop peeling
from happening if the code size increase created by
the optimization is above the threshold.
--max-id-bound=<n>
Sets the maximum value for the id bound for the moudle. The
default is the minimum value for this limit, 0x3FFFFF. See
section 2.17 of the Spir-V specification.
--merge-blocks
Join two blocks into a single block if the second has the
first as its only predecessor. Performed only on entry point
call tree functions.
--merge-return
Changes functions that have multiple return statements so they
have a single return statement.
For structured control flow it is assumed that the only
unreachable blocks in the function are trivial merge and continue
blocks.
A trivial merge block contains the label and an OpUnreachable
instructions, nothing else. A trivial continue block contain a
label and an OpBranch to the header, nothing else.
These conditions are guaranteed to be met after running
dead-branch elimination.
--loop-unswitch
Hoists loop-invariant conditionals out of loops by duplicating
the loop on each branch of the conditional and adjusting each
copy of the loop.
-O
Optimize for performance. Apply a sequence of transformations
in an attempt to improve the performance of the generated
code. For this version of the optimizer, this flag is equivalent
to specifying the following optimization code names:
%s
-Os
Optimize for size. Apply a sequence of transformations in an
attempt to minimize the size of the generated code. For this
version of the optimizer, this flag is equivalent to specifying
the following optimization code names:
%s
NOTE: The specific transformations done by -O and -Os change
from release to release.
-Oconfig=<file>
Apply the sequence of transformations indicated in <file>.
This file contains a sequence of strings separated by whitespace
(tabs, newlines or blanks). Each string is one of the flags
accepted by spirv-opt. Optimizations will be applied in the
sequence they appear in the file. This is equivalent to
specifying all the flags on the command line. For example,
given the file opts.cfg with the content:
--inline-entry-points-exhaustive
--eliminate-dead-code-aggressive
The following two invocations to spirv-opt are equivalent:
$ spirv-opt -Oconfig=opts.cfg program.spv
$ spirv-opt --inline-entry-points-exhaustive \
--eliminate-dead-code-aggressive program.spv
Lines starting with the character '#' in the configuration
file indicate a comment and will be ignored.
The -O, -Os, and -Oconfig flags act as macros. Using one of them
is equivalent to explicitly inserting the underlying flags at
that position in the command line. For example, the invocation
'spirv-opt --merge-blocks -O ...' applies the transformation
--merge-blocks followed by all the transformations implied by
-O.
--print-all
Print SPIR-V assembly to standard error output before each pass
and after the last pass.
--private-to-local
Change the scope of private variables that are used in a single
function to that function.
--reduce-load-size
Replaces loads of composite objects where not every component is
used by loads of just the elements that are used.
--redundancy-elimination
Looks for instructions in the same function that compute the
same value, and deletes the redundant ones.
--relax-struct-store
Allow store from one struct type to a different type with
compatible layout and members. This option is forwarded to the
validator.
--remove-duplicates
Removes duplicate types, decorations, capabilities and extension
instructions.
--replace-invalid-opcode
Replaces instructions whose opcode is valid for shader modules,
but not for the current shader stage. To have an effect, all
entry points must have the same execution model.
--ssa-rewrite
Replace loads and stores to function local variables with
operations on SSA IDs.
--scalar-replacement[=<n>]
Replace aggregate function scope variables that are only accessed
via their elements with new function variables representing each
element. <n> is a limit on the size of the aggragates that will
be replaced. 0 means there is no limit. The default value is
100.
--set-spec-const-default-value "<spec id>:<default value> ..."
Set the default values of the specialization constants with
<spec id>:<default value> pairs specified in a double-quoted
string. <spec id>:<default value> pairs must be separated by
blank spaces, and in each pair, spec id and default value must
be separated with colon ':' without any blank spaces in between.
e.g.: --set-spec-const-default-value "1:100 2:400"
--simplify-instructions
Will simplify all instructions in the function as much as
possible.
--skip-validation
Will not validate the SPIR-V before optimizing. If the SPIR-V
is invalid, the optimizer may fail or generate incorrect code.
This options should be used rarely, and with caution.
--strength-reduction
Replaces instructions with equivalent and less expensive ones.
--strip-debug
Remove all debug instructions.
--strip-reflect
Remove all reflection information. For now, this covers
reflection information defined by SPV_GOOGLE_hlsl_functionality1.
--target-env=<env>
Set the target environment. Without this flag the target
enviroment defaults to spv1.3.
<env> must be one of vulkan1.0, vulkan1.1, opencl2.2, spv1.0,
spv1.1, spv1.2, spv1.3, or webgpu0.
--time-report
Print the resource utilization of each pass (e.g., CPU time,
RSS) to standard error output. Currently it supports only Unix
systems. This option is the same as -ftime-report in GCC. It
prints CPU/WALL/USR/SYS time (and RSS if possible), but note that
USR/SYS time are returned by getrusage() and can have a small
error.
--upgrade-memory-model
Upgrades the Logical GLSL450 memory model to Logical VulkanKHR.
Transforms memory, image, atomic and barrier operations to conform
to that model's requirements.
--vector-dce
This pass looks for components of vectors that are unused, and
removes them from the vector. Note this would still leave around
lots of dead code that a pass of ADCE will be able to remove.
--webgpu-mode
Turns on the prescribed passes for WebGPU and sets the target
environmet to webgpu0. Other passes may be turned on via
additional flags, but such combinations are not tested.
Using --target-env with this flag is not allowed.
This flag is the equivalent of passing in --target-env=webgpu0
and specifying the following optimization code names:
%s
NOTE: This flag is a WIP and its behaviour is subject to change.
--workaround-1209
Rewrites instructions for which there are known driver bugs to
avoid triggering those bugs.
Current workarounds: Avoid OpUnreachable in loops.
--unify-const
Remove the duplicated constants.
-h, --help
Print this help.
--version
Display optimizer version information.
)",
program, program, GetLegalizationPasses().c_str(),
GetOptimizationPasses().c_str(), GetSizePasses().c_str(),
GetWebGPUPasses().c_str());
}
// Reads command-line flags the file specified in |oconfig_flag|. This string
// is assumed to have the form "-Oconfig=FILENAME". This function parses the
// string and extracts the file name after the '=' sign.
//
// Flags found in |FILENAME| are pushed at the end of the vector |file_flags|.
//
// This function returns true on success, false on failure.
bool ReadFlagsFromFile(const char* oconfig_flag,
std::vector<std::string>* file_flags) {
const char* fname = strchr(oconfig_flag, '=');
if (fname == nullptr || fname[0] != '=') {
spvtools::Errorf(opt_diagnostic, nullptr, {}, "Invalid -Oconfig flag %s",
oconfig_flag);
return false;
}
fname++;
std::ifstream input_file;
input_file.open(fname);
if (input_file.fail()) {
spvtools::Errorf(opt_diagnostic, nullptr, {}, "Could not open file '%s'",
fname);
return false;
}
std::string line;
while (std::getline(input_file, line)) {
// Ignore empty lines and lines starting with the comment marker '#'.
if (line.length() == 0 || line[0] == '#') {
continue;
}
// Tokenize the line. Add all found tokens to the list of found flags. This
// mimics the way the shell will parse whitespace on the command line. NOTE:
// This does not support quoting and it is not intended to.
std::istringstream iss(line);
while (!iss.eof()) {
std::string flag;
iss >> flag;
file_flags->push_back(flag);
}
}
return true;
}
OptStatus ParseFlags(int argc, const char** argv,
spvtools::Optimizer* optimizer, const char** in_file,
const char** out_file,
spvtools::ValidatorOptions* validator_options,
spvtools::OptimizerOptions* optimizer_options);
// Parses and handles the -Oconfig flag. |prog_name| contains the name of
// the spirv-opt binary (used to build a new argv vector for the recursive
// invocation to ParseFlags). |opt_flag| contains the -Oconfig=FILENAME flag.
// |optimizer|, |in_file|, |out_file|, |validator_options|, and
// |optimizer_options| are as in ParseFlags.
//
// This returns the same OptStatus instance returned by ParseFlags.
OptStatus ParseOconfigFlag(const char* prog_name, const char* opt_flag,
spvtools::Optimizer* optimizer, const char** in_file,
const char** out_file,
spvtools::ValidatorOptions* validator_options,
spvtools::OptimizerOptions* optimizer_options) {
std::vector<std::string> flags;
flags.push_back(prog_name);
std::vector<std::string> file_flags;
if (!ReadFlagsFromFile(opt_flag, &file_flags)) {
spvtools::Error(opt_diagnostic, nullptr, {},
"Could not read optimizer flags from configuration file");
return {OPT_STOP, 1};
}
flags.insert(flags.end(), file_flags.begin(), file_flags.end());
const char** new_argv = new const char*[flags.size()];
for (size_t i = 0; i < flags.size(); i++) {
if (flags[i].find("-Oconfig=") != std::string::npos) {
spvtools::Error(
opt_diagnostic, nullptr, {},
"Flag -Oconfig= may not be used inside the configuration file");
return {OPT_STOP, 1};
}
new_argv[i] = flags[i].c_str();
}
auto ret_val =
ParseFlags(static_cast<int>(flags.size()), new_argv, optimizer, in_file,
out_file, validator_options, optimizer_options);
delete[] new_argv;
return ret_val;
}
// Canonicalize the flag in |argv[argi]| of the form '--pass arg' into
// '--pass=arg'. The optimizer only accepts arguments to pass names that use the
// form '--pass_name=arg'. Since spirv-opt also accepts the other form, this
// function makes the necessary conversion.
//
// Pass flags that require additional arguments should be handled here. Note
// that additional arguments should be given as a single string. If the flag
// requires more than one argument, the pass creator in
// Optimizer::GetPassFromFlag() should parse it accordingly (e.g., see the
// handler for --set-spec-const-default-value).
//
// If the argument requests one of the passes that need an additional argument,
// |argi| is modified to point past the current argument, and the string
// "argv[argi]=argv[argi + 1]" is returned. Otherwise, |argi| is unmodified and
// the string "|argv[argi]|" is returned.
std::string CanonicalizeFlag(const char** argv, int argc, int* argi) {
const char* cur_arg = argv[*argi];
const char* next_arg = (*argi + 1 < argc) ? argv[*argi + 1] : nullptr;
std::ostringstream canonical_arg;
canonical_arg << cur_arg;
// NOTE: DO NOT ADD NEW FLAGS HERE.
//
// These flags are supported for backwards compatibility. When adding new
// passes that need extra arguments in its command-line flag, please make them
// use the syntax "--pass_name[=pass_arg].
if (0 == strcmp(cur_arg, "--set-spec-const-default-value") ||
0 == strcmp(cur_arg, "--loop-fission") ||
0 == strcmp(cur_arg, "--loop-fusion") ||
0 == strcmp(cur_arg, "--loop-unroll-partial") ||
0 == strcmp(cur_arg, "--loop-peeling-threshold")) {
if (next_arg) {
canonical_arg << "=" << next_arg;
++(*argi);
}
}
return canonical_arg.str();
}
// Parses command-line flags. |argc| contains the number of command-line flags.
// |argv| points to an array of strings holding the flags. |optimizer| is the
// Optimizer instance used to optimize the program.
//
// On return, this function stores the name of the input program in |in_file|.
// The name of the output file in |out_file|. The return value indicates whether
// optimization should continue and a status code indicating an error or
// success.
OptStatus ParseFlags(int argc, const char** argv,
spvtools::Optimizer* optimizer, const char** in_file,
const char** out_file,
spvtools::ValidatorOptions* validator_options,
spvtools::OptimizerOptions* optimizer_options) {
std::vector<std::string> pass_flags;
bool target_env_set = false;
bool webgpu_mode_set = false;
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(opt_diagnostic, SPV_MSG_INFO, nullptr, {}, "%s\n",
spvSoftwareVersionDetailsString());
return {OPT_STOP, 0};
} else if (0 == strcmp(cur_arg, "--help") || 0 == strcmp(cur_arg, "-h")) {
PrintUsage(argv[0]);
return {OPT_STOP, 0};
} else if (0 == strcmp(cur_arg, "-o")) {
if (!*out_file && argi + 1 < argc) {
*out_file = argv[++argi];
} else {
PrintUsage(argv[0]);
return {OPT_STOP, 1};
}
} else if ('\0' == cur_arg[1]) {
// Setting a filename of "-" to indicate stdin.
if (!*in_file) {
*in_file = cur_arg;
} else {
spvtools::Error(opt_diagnostic, nullptr, {},
"More than one input file specified");
return {OPT_STOP, 1};
}
} else if (0 == strncmp(cur_arg, "-Oconfig=", sizeof("-Oconfig=") - 1)) {
OptStatus status =
ParseOconfigFlag(argv[0], cur_arg, optimizer, in_file, out_file,
validator_options, optimizer_options);
if (status.action != OPT_CONTINUE) {
return status;
}
} else if (0 == strcmp(cur_arg, "--skip-validation")) {
optimizer_options->set_run_validator(false);
} else if (0 == strcmp(cur_arg, "--print-all")) {
optimizer->SetPrintAll(&std::cerr);
} else if (0 == strcmp(cur_arg, "--time-report")) {
optimizer->SetTimeReport(&std::cerr);
} else if (0 == strcmp(cur_arg, "--relax-struct-store")) {
validator_options->SetRelaxStructStore(true);
} else if (0 == strncmp(cur_arg, "--max-id-bound=",
sizeof("--max-id-bound=") - 1)) {
auto split_flag = spvtools::utils::SplitFlagArgs(cur_arg);
// Will not allow values in the range [2^31,2^32).
uint32_t max_id_bound =
static_cast<uint32_t>(atoi(split_flag.second.c_str()));
// That SPIR-V mandates the minimum value for max id bound but
// implementations may allow higher minimum bounds.
if (max_id_bound < kDefaultMaxIdBound) {
spvtools::Error(opt_diagnostic, nullptr, {},
"The max id bound must be at least 0x3FFFFF");
return {OPT_STOP, 1};
}
optimizer_options->set_max_id_bound(max_id_bound);
validator_options->SetUniversalLimit(spv_validator_limit_max_id_bound,
max_id_bound);
} else if (0 == strncmp(cur_arg,
"--target-env=", sizeof("--target-env=") - 1)) {
if (webgpu_mode_set) {
spvtools::Error(opt_diagnostic, nullptr, {},
"Cannot use both --webgpu-mode and --target-env at "
"the same time");
return {OPT_STOP, 1};
}
const auto split_flag = spvtools::utils::SplitFlagArgs(cur_arg);
const auto target_env_str = split_flag.second.c_str();
spv_target_env target_env;
if (!spvParseTargetEnv(target_env_str, &target_env)) {
spvtools::Error(opt_diagnostic, nullptr, {},
"Invalid value passed to --target-env");
return {OPT_STOP, 1};
}
optimizer->SetTargetEnv(target_env);
} else if (0 == strcmp(cur_arg, "--webgpu-mode")) {
if (target_env_set) {
spvtools::Error(opt_diagnostic, nullptr, {},
"Cannot use both --webgpu-mode and --target-env at "
"the same time");
return {OPT_STOP, 1};
}
optimizer->SetTargetEnv(SPV_ENV_WEBGPU_0);
optimizer->RegisterWebGPUPasses();
} else {
// Some passes used to accept the form '--pass arg', canonicalize them
// to '--pass=arg'.
pass_flags.push_back(CanonicalizeFlag(argv, argc, &argi));
// If we were requested to legalize SPIR-V generated from the HLSL
// front-end, skip validation.
if (0 == strcmp(cur_arg, "--legalize-hlsl")) {
validator_options->SetRelaxLogicalPointer(true);
}
}
} else {
if (!*in_file) {
*in_file = cur_arg;
} else {
spvtools::Error(opt_diagnostic, nullptr, {},
"More than one input file specified");
return {OPT_STOP, 1};
}
}
}
if (!optimizer->RegisterPassesFromFlags(pass_flags)) {
return {OPT_STOP, 1};
}
return {OPT_CONTINUE, 0};
}
} // namespace
int main(int argc, const char** argv) {
const char* in_file = nullptr;
const char* out_file = nullptr;
spv_target_env target_env = kDefaultEnvironment;
spvtools::Optimizer optimizer(target_env);
optimizer.SetMessageConsumer(spvtools::utils::CLIMessageConsumer);
spvtools::ValidatorOptions validator_options;
spvtools::OptimizerOptions optimizer_options;
OptStatus status = ParseFlags(argc, argv, &optimizer, &in_file, &out_file,
&validator_options, &optimizer_options);
optimizer_options.set_validator_options(validator_options);
if (status.action == OPT_STOP) {
return status.code;
}
if (out_file == nullptr) {
spvtools::Error(opt_diagnostic, nullptr, {}, "-o required");
return 1;
}
std::vector<uint32_t> binary;
if (!ReadFile<uint32_t>(in_file, "rb", &binary)) {
return 1;
}
// By using the same vector as input and output, we save time in the case
// that there was no change.
bool ok =
optimizer.Run(binary.data(), binary.size(), &binary, optimizer_options);
if (!WriteFile<uint32_t>(out_file, "wb", binary.data(), binary.size())) {
return 1;
}
return ok ? 0 : 1;
}