https://github.com/halide/Halide
Tip revision: 8d447e559f433124b595d74f2eef12c27914b802 authored by Andrew Adams on 11 May 2018, 16:22:21 UTC
Better default schedule
Better default schedule
Tip revision: 8d447e5
Pipeline.cpp
#include <algorithm>
#include "Argument.h"
#include "FindCalls.h"
#include "Func.h"
#include "IRVisitor.h"
#include "InferArguments.h"
#include "LLVM_Headers.h"
#include "LLVM_Output.h"
#include "Lower.h"
#include "Outputs.h"
#include "ParamMap.h"
#include "Pipeline.h"
#include "PrintLoopNest.h"
#include "RealizationOrder.h"
using namespace Halide::Internal;
namespace Halide {
using std::set;
using std::string;
using std::vector;
namespace {
std::string output_name(const string &filename, const string &fn_name, const char* ext) {
return !filename.empty() ? filename : (fn_name + ext);
}
std::string output_name(const string &filename, const Module &m, const char* ext) {
return output_name(filename, m.name(), ext);
}
Outputs static_library_outputs(const string &filename_prefix, const Target &target) {
Outputs outputs = Outputs().c_header(filename_prefix + ".h");
if (target.os == Target::Windows && !target.has_feature(Target::MinGW)) {
outputs = outputs.static_library(filename_prefix + ".lib");
} else {
outputs = outputs.static_library(filename_prefix + ".a");
}
return outputs;
}
} // namespace
struct PipelineContents {
mutable RefCount ref_count;
// Cached lowered stmt
Module module;
// Name of the generated function
string name;
// Cached jit-compiled code
JITModule jit_module;
Target jit_target;
/** Clear all cached state */
void invalidate_cache() {
module = Module("", Target());
jit_module = JITModule();
jit_target = Target();
inferred_args.clear();
}
// The outputs
vector<Function> outputs;
// JIT custom overrides
JITHandlers jit_handlers;
/** The user context that's used when jitting. This is not
* settable by user code, but is reserved for internal use. Note
* that this is an Argument + Parameter (rather than a
* Param<void*>) so that we can exclude it from the
* ObjectInstanceRegistry. */
InferredArgument user_context_arg;
/** A set of custom passes to use when lowering this Func. */
vector<CustomLoweringPass> custom_lowering_passes;
/** The inferred arguments. Also the arguments to the main
* function in the jit_module above. The two must be updated
* together. */
vector<InferredArgument> inferred_args;
/** List of C funtions and Funcs to satisfy HalideExtern* and
* define_extern calls. */
std::map<std::string, JITExtern> jit_externs;
PipelineContents() :
module("", Target()) {
user_context_arg.arg = Argument("__user_context", Argument::InputScalar, type_of<const void*>(), 0);
user_context_arg.param = Parameter(Handle(), false, 0, "__user_context",
/*is_explicit_name*/ true);
}
~PipelineContents() {
clear_custom_lowering_passes();
}
void clear_custom_lowering_passes() {
invalidate_cache();
for (size_t i = 0; i < custom_lowering_passes.size(); i++) {
if (custom_lowering_passes[i].deleter) {
custom_lowering_passes[i].deleter();
}
}
custom_lowering_passes.clear();
}
};
namespace Internal {
template<>
RefCount &ref_count<PipelineContents>(const PipelineContents *p) {
return p->ref_count;
}
template<>
void destroy<PipelineContents>(const PipelineContents *p) {
delete p;
}
}
Pipeline::Pipeline() : contents(nullptr) {
}
bool Pipeline::defined() const {
return contents.defined();
}
Pipeline::Pipeline(Func output) : contents(new PipelineContents) {
output.function().freeze();
contents->outputs.push_back(output.function());
}
Pipeline::Pipeline(const vector<Func> &outputs) : contents(new PipelineContents) {
for (Func f: outputs) {
f.function().freeze();
contents->outputs.push_back(f.function());
}
}
vector<Func> Pipeline::outputs() const {
vector<Func> funcs;
for (Function f : contents->outputs) {
funcs.push_back(Func(f));
}
return funcs;
}
string Pipeline::auto_schedule(const Target &target, const MachineParams &arch_params) {
user_assert(target.arch == Target::X86 || target.arch == Target::ARM ||
target.arch == Target::POWERPC || target.arch == Target::MIPS)
<< "Automatic scheduling is currently supported only on these architectures.";
return generate_schedules(contents->outputs, target, arch_params);
}
Func Pipeline::get_func(size_t index) {
// Compute an environment
std::map<string, Function> env;
for (Function f : contents->outputs) {
std::map<string, Function> more_funcs = find_transitive_calls(f);
env.insert(more_funcs.begin(), more_funcs.end());
}
// Compute a topological order
vector<string> order = topological_order(contents->outputs, env);
user_assert(index < order.size())
<< "Index value passed is " << index << "; however, there are only "
<< order.size() << " functions in the pipeline.\n";
return Func(env.find(order[index])->second);
}
void Pipeline::compile_to(const Outputs &output_files,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
compile_to_module(args, fn_name, target).compile(output_files);
}
void Pipeline::compile_to_bitcode(const string &filename,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
m.compile(Outputs().bitcode(output_name(filename, m, ".bc")));
}
void Pipeline::compile_to_llvm_assembly(const string &filename,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
m.compile(Outputs().llvm_assembly(output_name(filename, m, ".ll")));
}
void Pipeline::compile_to_object(const string &filename,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
const char* ext = target.os == Target::Windows && !target.has_feature(Target::MinGW) ? ".obj" : ".o";
m.compile(Outputs().object(output_name(filename, m, ext)));
}
void Pipeline::compile_to_header(const string &filename,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
m.compile(Outputs().c_header(output_name(filename, m, ".h")));
}
void Pipeline::compile_to_assembly(const string &filename,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
m.compile(Outputs().assembly(output_name(filename, m, ".s")));
}
void Pipeline::compile_to_c(const string &filename,
const vector<Argument> &args,
const string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
m.compile(Outputs().c_source(output_name(filename, m, ".c")));
}
void Pipeline::print_loop_nest() {
user_assert(defined()) << "Can't print loop nest of undefined Pipeline.\n";
std::cerr << Halide::Internal::print_loop_nest(contents->outputs);
}
void Pipeline::compile_to_lowered_stmt(const string &filename,
const vector<Argument> &args,
StmtOutputFormat fmt,
const Target &target) {
Module m = compile_to_module(args, "", target);
Outputs outputs;
if (fmt == HTML) {
outputs = Outputs().stmt_html(output_name(filename, m, ".html"));
} else {
outputs = Outputs().stmt(output_name(filename, m, ".stmt"));
}
m.compile(outputs);
}
void Pipeline::compile_to_static_library(const string &filename_prefix,
const vector<Argument> &args,
const std::string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
Outputs outputs = static_library_outputs(filename_prefix, target);
m.compile(outputs);
}
void Pipeline::compile_to_multitarget_static_library(const std::string &filename_prefix,
const std::vector<Argument> &args,
const std::vector<Target> &targets) {
auto module_producer = [this, &args](const std::string &name, const Target &target) -> Module {
return compile_to_module(args, name, target);
};
Outputs outputs = static_library_outputs(filename_prefix, targets.back());
compile_multitarget(generate_function_name(), outputs, targets, module_producer);
}
void Pipeline::compile_to_file(const string &filename_prefix,
const vector<Argument> &args,
const std::string &fn_name,
const Target &target) {
Module m = compile_to_module(args, fn_name, target);
Outputs outputs = Outputs().c_header(filename_prefix + ".h");
if (target.os == Target::Windows && !target.has_feature(Target::MinGW)) {
outputs = outputs.object(filename_prefix + ".obj");
} else {
outputs = outputs.object(filename_prefix + ".o");
}
m.compile(outputs);
}
vector<Argument> Pipeline::infer_arguments(Stmt body) {
contents->inferred_args = ::infer_arguments(body, contents->outputs);
// Add the user context argument if it's not already there, or hook up our user context
// Parameter to any existing one.
bool has_user_context = false;
for (auto &arg : contents->inferred_args) {
if (arg.arg.name == contents->user_context_arg.arg.name) {
arg = contents->user_context_arg;
has_user_context = true;
}
}
if (!has_user_context) {
contents->inferred_args.push_back(contents->user_context_arg);
}
// Return the inferred argument types, minus any constant images
// (we'll embed those in the binary by default), and minus the user_context arg.
vector<Argument> result;
for (const InferredArgument &arg : contents->inferred_args) {
debug(1) << "Inferred argument: " << arg.arg.type << " " << arg.arg.name << "\n";
if (!arg.buffer.defined() &&
arg.arg.name != contents->user_context_arg.arg.name) {
result.push_back(arg.arg);
}
}
return result;
}
vector<Argument> Pipeline::infer_arguments() {
return infer_arguments(Stmt());
}
Module Pipeline::compile_to_module(const vector<Argument> &args,
const string &fn_name,
const Target &target,
const LinkageType linkage_type) {
user_assert(defined()) << "Can't compile undefined Pipeline.\n";
for (Function f : contents->outputs) {
user_assert(f.has_pure_definition() || f.has_extern_definition())
<< "Can't compile Pipeline with undefined output Func: " << f.name() << ".\n";
}
string new_fn_name(fn_name);
if (new_fn_name.empty()) {
new_fn_name = generate_function_name();
}
internal_assert(!new_fn_name.empty()) << "new_fn_name cannot be empty\n";
// TODO: Assert that the function name is legal
vector<Argument> lowering_args(args);
// If the target specifies user context but it's not in the args
// vector, add it at the start (the jit path puts it in there
// explicitly).
const bool requires_user_context = target.has_feature(Target::UserContext);
bool has_user_context = false;
for (Argument arg : lowering_args) {
if (arg.name == contents->user_context_arg.arg.name) {
has_user_context = true;
}
}
if (requires_user_context && !has_user_context) {
lowering_args.insert(lowering_args.begin(), contents->user_context_arg.arg);
}
const Module &old_module = contents->module;
bool same_compile = !old_module.functions().empty() && old_module.target() == target;
// Either generated name or one of the LoweredFuncs in the existing module has the same name.
same_compile = same_compile && fn_name.empty();
bool found_name = false;
for (const auto &lf : old_module.functions()) {
if (lf.name == fn_name) {
found_name = true;
break;
}
}
same_compile = same_compile && found_name;
// Number of args + number of outputs is the same as total args in existing LoweredFunc
same_compile = same_compile && (lowering_args.size() + outputs().size()) == old_module.functions().front().args.size();
// The initial args are the same.
same_compile = same_compile && std::equal(lowering_args.begin(), lowering_args.end(), old_module.functions().front().args.begin());
// Linkage is the same.
same_compile = same_compile && old_module.functions().front().linkage == linkage_type;
// The outputs of a Pipeline cannot change, so no need to test them.
if (same_compile) {
// We can avoid relowering and just reuse the existing module.
debug(2) << "Reusing old module\n";
} else {
vector<IRMutator2 *> custom_passes;
for (CustomLoweringPass p : contents->custom_lowering_passes) {
custom_passes.push_back(p.pass);
}
contents->module = lower(contents->outputs, new_fn_name, target, lowering_args, linkage_type, custom_passes);
}
return contents->module;
}
std::string Pipeline::generate_function_name() const {
user_assert(defined()) << "Pipeline is undefined\n";
// Come up with a name for a generated function
string name = contents->outputs[0].name();
for (size_t i = 0; i < name.size(); i++) {
if (!isalnum(name[i])) {
name[i] = '_';
}
}
return name;
}
void *Pipeline::compile_jit(const Target &target_arg) {
user_assert(defined()) << "Pipeline is undefined\n";
Target target(target_arg);
target.set_feature(Target::JIT);
target.set_feature(Target::UserContext);
debug(2) << "jit-compiling for: " << target_arg << "\n";
// If we're re-jitting for the same target, we can just keep the
// old jit module.
if (contents->jit_target == target &&
contents->jit_module.compiled()) {
debug(2) << "Reusing old jit module compiled for :\n" << contents->jit_target << "\n";
return contents->jit_module.main_function();
}
// Clear all cached info in case there is an error.
contents->invalidate_cache();
contents->jit_target = target;
// Infer an arguments vector
infer_arguments();
// Don't actually use the return value - it embeds all constant
// images and we don't want to do that when jitting. Instead
// use the vector of parameters found to make a more complete
// arguments list.
vector<Argument> args;
for (const InferredArgument &arg : contents->inferred_args) {
args.push_back(arg.arg);
}
// Come up with a name for the generated function
string name = generate_function_name();
// Compile to a module and also compile any submodules.
Module module = compile_to_module(args, name, target).resolve_submodules();
auto f = module.get_function_by_name(name);
std::map<std::string, JITExtern> lowered_externs = contents->jit_externs;
// Compile to jit module
JITModule jit_module(module, f, make_externs_jit_module(target_arg, lowered_externs));
// Dump bitcode to a file if the environment variable
// HL_GENBITCODE is defined to a nonzero value.
if (atoi(get_env_variable("HL_GENBITCODE").c_str())) {
string program_name = running_program_name();
if (program_name.empty()) {
program_name = "unknown" + unique_name('_').substr(1);
}
string file_name = program_name + "_" + name + "_" + unique_name('g').substr(1) + ".bc";
debug(4) << "Saving bitcode to: " << file_name << "\n";
module.compile(Outputs().bitcode(file_name));
}
contents->jit_module = jit_module;
return jit_module.main_function();
}
void Pipeline::set_error_handler(void (*handler)(void *, const char *)) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_handlers.custom_error = handler;
}
void Pipeline::set_custom_allocator(void *(*cust_malloc)(void *, size_t),
void (*cust_free)(void *, void *)) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_handlers.custom_malloc = cust_malloc;
contents->jit_handlers.custom_free = cust_free;
}
void Pipeline::set_custom_do_par_for(int (*cust_do_par_for)(void *, int (*)(void *, int, uint8_t *), int, int, uint8_t *)) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_handlers.custom_do_par_for = cust_do_par_for;
}
void Pipeline::set_custom_do_task(int (*cust_do_task)(void *, int (*)(void *, int, uint8_t *), int, uint8_t *)) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_handlers.custom_do_task = cust_do_task;
}
void Pipeline::set_custom_trace(int (*trace_fn)(void *, const halide_trace_event_t *)) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_handlers.custom_trace = trace_fn;
}
void Pipeline::set_custom_print(void (*cust_print)(void *, const char *)) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_handlers.custom_print = cust_print;
}
void Pipeline::set_jit_externs(const std::map<std::string, JITExtern> &externs) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->jit_externs = externs;
invalidate_cache();
}
const std::map<std::string, JITExtern> &Pipeline::get_jit_externs() {
user_assert(defined()) << "Pipeline is undefined\n";
return contents->jit_externs;
}
void Pipeline::add_custom_lowering_pass(IRMutator2 *pass, std::function<void()> deleter) {
user_assert(defined()) << "Pipeline is undefined\n";
contents->invalidate_cache();
CustomLoweringPass p = {pass, deleter};
contents->custom_lowering_passes.push_back(p);
}
void Pipeline::clear_custom_lowering_passes() {
if (!defined()) return;
contents->clear_custom_lowering_passes();
}
const vector<CustomLoweringPass> &Pipeline::custom_lowering_passes() {
user_assert(defined()) << "Pipeline is undefined\n";
return contents->custom_lowering_passes;
}
const JITHandlers &Pipeline::jit_handlers() {
user_assert(defined()) << "Pipeline is undefined\n";
return contents->jit_handlers;
}
Realization Pipeline::realize(vector<int32_t> sizes, const Target &target,
const ParamMap ¶m_map) {
user_assert(defined()) << "Pipeline is undefined\n";
vector<Buffer<>> bufs;
for (auto & out : contents->outputs) {
user_assert(out.has_pure_definition() || out.has_extern_definition()) <<
"Can't realize Pipeline with undefined output Func: " << out.name() << ".\n";
for (Type t : out.output_types()) {
bufs.emplace_back(t, sizes);
}
}
Realization r(bufs);
realize(r, target, param_map);
for (size_t i = 0; i < r.size(); i++) {
r[i].copy_to_host();
}
return r;
}
Realization Pipeline::realize(int x_size, int y_size, int z_size, int w_size, const Target &target,
const ParamMap ¶m_map) {
return realize({x_size, y_size, z_size, w_size}, target, param_map);
}
Realization Pipeline::realize(int x_size, int y_size, int z_size, const Target &target,
const ParamMap ¶m_map) {
return realize({x_size, y_size, z_size}, target, param_map);
}
Realization Pipeline::realize(int x_size, int y_size, const Target &target,
const ParamMap ¶m_map) {
return realize({x_size, y_size}, target, param_map);
}
Realization Pipeline::realize(int x_size, const Target &target,
const ParamMap ¶m_map) {
// Use an explicit vector here, since {x_size} can be interpreted
// as a scalar initializer
vector<int32_t> v = {x_size};
return realize(v, target, param_map);
}
Realization Pipeline::realize(const Target &target,
const ParamMap ¶m_map) {
return realize(vector<int32_t>(), target, param_map);
}
namespace {
struct ErrorBuffer {
enum { MaxBufSize = 4096 };
char buf[MaxBufSize];
int end;
ErrorBuffer() {
end = 0;
}
void concat(const char *message) {
size_t len = strlen(message);
if (len && message[len-1] != '\n') {
// Claim some extra space for a newline.
len++;
}
// Atomically claim some space in the buffer
#ifdef _MSC_VER
int old_end = _InterlockedExchangeAdd((volatile long *)(&end), len);
#else
int old_end = __sync_fetch_and_add(&end, len);
#endif
if (old_end + len >= MaxBufSize - 1) {
// Out of space
return;
}
for (size_t i = 0; i < len - 1; i++) {
buf[old_end + i] = message[i];
}
if (buf[old_end + len - 2] != '\n') {
buf[old_end + len - 1] = '\n';
}
}
std::string str() const {
return std::string(buf, end);
}
static void handler(void *ctx, const char *message) {
if (ctx) {
JITUserContext *ctx1 = (JITUserContext *)ctx;
ErrorBuffer *buf = (ErrorBuffer *)ctx1->user_context;
buf->concat(message);
}
}
};
struct JITFuncCallContext {
ErrorBuffer error_buffer;
JITUserContext jit_context;
bool custom_error_handler;
JITFuncCallContext(const JITHandlers &handlers) {
void *user_context = nullptr;
JITHandlers local_handlers = handlers;
if (local_handlers.custom_error == nullptr) {
custom_error_handler = false;
local_handlers.custom_error = ErrorBuffer::handler;
user_context = &error_buffer;
} else {
custom_error_handler = true;
}
JITSharedRuntime::init_jit_user_context(jit_context, user_context, local_handlers);
debug(2) << "custom_print: " << (void *)jit_context.handlers.custom_print << '\n'
<< "custom_malloc: " << (void *)jit_context.handlers.custom_malloc << '\n'
<< "custom_free: " << (void *)jit_context.handlers.custom_free << '\n'
<< "custom_do_task: " << (void *)jit_context.handlers.custom_do_task << '\n'
<< "custom_do_par_for: " << (void *)jit_context.handlers.custom_do_par_for << '\n'
<< "custom_error: " << (void *)jit_context.handlers.custom_error << '\n'
<< "custom_trace: " << (void *)jit_context.handlers.custom_trace << '\n';
}
void report_if_error(int exit_status) {
// Only report the errors if no custom error handler was installed
if (exit_status && !custom_error_handler) {
std::string output = error_buffer.str();
if (output.empty()) {
output = ("The pipeline returned exit status " +
std::to_string(exit_status) +
" but halide_error was never called.\n");
}
halide_runtime_error << output;
error_buffer.end = 0;
}
}
void finalize(int exit_status) {
report_if_error(exit_status);
}
};
} // namespace
struct Pipeline::JITCallArgs {
size_t size{0};
const void **store;
JITCallArgs(size_t size) : size(size) {
if (size > (sizeof(fixed_store) / sizeof(fixed_store[0]))) {
// TODO(zalman): Call new[]?
store = (const void **)malloc(sizeof(void *) * size);
} else {
store = fixed_store;
}
}
~JITCallArgs() {
if (store != fixed_store) {
free(store);
}
}
private:
const void *fixed_store[64];
JITCallArgs(const JITCallArgs &) = delete;
JITCallArgs(JITCallArgs &&) = delete;
void operator=(const JITCallArgs &) = delete;
};
// Make a vector of void *'s to pass to the jit call using the
// currently bound value for all of the params and image
// params.
void Pipeline::prepare_jit_call_arguments(RealizationArg &outputs, const Target &target,
const ParamMap ¶m_map, void *user_context,
bool is_bounds_inference, JITCallArgs &args_result) {
user_assert(defined()) << "Can't realize an undefined Pipeline\n";
JITModule &compiled_module = contents->jit_module;
internal_assert(compiled_module.argv_function());
const bool no_param_map = ¶m_map == &ParamMap::empty_map();
// Come up with the void * arguments to pass to the argv function
size_t arg_index = 0;
for (const InferredArgument &arg : contents->inferred_args) {
if (arg.param.defined()) {
if (arg.param.same_as(contents->user_context_arg.param)) {
args_result.store[arg_index++] = user_context;
} else {
Buffer<> *buf_out_param = nullptr;
const Parameter &p = no_param_map ? arg.param : param_map.map(arg.param, buf_out_param);
user_assert(is_bounds_inference || !buf_out_param)
<< "Cannot pass Buffer<> pointers in parameters map to a compute call.\n";
if (p.is_buffer()) {
// ImageParam arg
Buffer<> buf = p.buffer();
if (buf.defined()) {
args_result.store[arg_index++] = p.raw_buffer();
} else {
// Unbound
args_result.store[arg_index++] = nullptr;
}
debug(1) << "JIT input ImageParam argument ";
} else {
args_result.store[arg_index++] = p.scalar_address();
debug(1) << "JIT input scalar argument ";
}
}
} else {
debug(1) << "JIT input Image argument ";
internal_assert(arg.buffer.defined());
args_result.store[arg_index++] = arg.buffer.raw_buffer();
}
const void *ptr = args_result.store[arg_index - 1];
debug(1) << arg.arg.name << " @ " << ptr << "\n";
}
// Then the outputs
if (outputs.r) {
for (size_t i = 0; i < outputs.r->size(); i++) {
const halide_buffer_t *buf = (*outputs.r)[i].raw_buffer();
args_result.store[arg_index++] = buf;
debug(1) << "JIT output buffer @ " << (const void *)buf << ", " << (const void *)buf->host << "\n";
}
} else if (outputs.buf) {
args_result.store[arg_index++] = outputs.buf;
debug(1) << "JIT output buffer @ " << (const void *)outputs.buf << ", " << (const void *)outputs.buf->host << "\n";
} else {
for (const Buffer<> &buffer : *outputs.buffer_list) {
const halide_buffer_t *buf = buffer.raw_buffer();
args_result.store[arg_index++] = buf;
debug(1) << "JIT output buffer @ " << (const void *)buf << ", " << (const void *)buf->host << "\n";
}
}
}
std::vector<JITModule>
Pipeline::make_externs_jit_module(const Target &target,
std::map<std::string, JITExtern> &externs_in_out) {
std::vector<JITModule> result;
// Externs that are Funcs get their own JITModule. All standalone functions are
// held in a single JITModule at the end of the list (if there are any).
JITModule free_standing_jit_externs;
for (std::map<std::string, JITExtern>::iterator iter = externs_in_out.begin();
iter != externs_in_out.end();
iter++) {
Pipeline pipeline = iter->second.pipeline();
if (pipeline.defined()) {
PipelineContents &pipeline_contents(*pipeline.contents);
// Ensure that the pipeline is compiled.
pipeline.compile_jit(target);
free_standing_jit_externs.add_dependency(pipeline_contents.jit_module);
free_standing_jit_externs.add_symbol_for_export(iter->first, pipeline_contents.jit_module.entrypoint_symbol());
void *address = pipeline_contents.jit_module.entrypoint_symbol().address;
std::vector<Type> arg_types;
// Add the arguments to the compiled pipeline
for (const InferredArgument &arg : pipeline_contents.inferred_args) {
// TODO: it's not clear whether arg.arg.type is correct for
// the arg.is_buffer() case (AFAIK, is_buffer()==true isn't possible
// in current mtrunk Halide, but may be in some side branches that
// have not yet landed, e.g. JavaScript). Forcing it to be
// the correct type here, just in case.
arg_types.push_back(arg.arg.is_buffer() ?
type_of<struct buffer_t *>() :
arg.arg.type);
}
// Add the outputs of the pipeline
for (size_t i = 0; i < pipeline_contents.outputs.size(); i++) {
arg_types.push_back(type_of<struct buffer_t *>());
}
ExternSignature signature(Int(32), false, arg_types);
iter->second = ExternCFunction(address, signature);
} else {
free_standing_jit_externs.add_extern_for_export(iter->first, iter->second.extern_c_function());
}
}
if (free_standing_jit_externs.compiled() || !free_standing_jit_externs.exports().empty()) {
result.push_back(free_standing_jit_externs);
}
return result;
}
void Pipeline::realize(RealizationArg outputs, const Target &t,
const ParamMap ¶m_map) {
Target target = t;
user_assert(defined()) << "Can't realize an undefined Pipeline\n";
debug(2) << "Realizing Pipeline for " << target << "\n";
if (outputs.r) {
for (size_t i = 0; i < outputs.r->size(); i++) {
user_assert((*outputs.r)[i].data() != nullptr)
<< "Buffer at " << &((*outputs.r)[i]) << " is unallocated. "
<< "The Buffers in a Realization passed to realize must all be allocated\n";
}
} else if (outputs.buffer_list) {
for (const Buffer<> &buf : *outputs.buffer_list) {
user_assert(buf.data() != nullptr)
<< "Buffer at " << &buf << " is unallocated. "
<< "The Buffers in a Realization passed to realize must all be allocated\n";
}
} else {
user_assert(outputs.buf && (outputs.buf->host || outputs.buf->device))
<< "Buffer at " << (void *)outputs.buf << " is unallocated. "
<< "The Buffers passed to realize must all be allocated\n";
}
// If target is unspecified...
if (target.os == Target::OSUnknown) {
// If we've already jit-compiled for a specific target, use that.
if (contents->jit_module.compiled()) {
target = contents->jit_target;
} else {
// Otherwise get the target from the environment
target = get_jit_target_from_environment();
}
}
// We need to make a context for calling the jitted function to
// carry the the set of custom handlers. Here's how handlers get
// called when running jitted code:
// There's a single shared module that includes runtime code like
// posix_error_handler.cpp. This module is created the first time
// you JIT something and is reused for all subsequent runs of
// jitted code for any pipeline with the same target.
// To handle events like printing, tracing, or errors, the jitted
// code calls things like halide_error or halide_print in the
// shared runtime, which in turn call global function pointer
// variables in the shared runtime (e.g. halide_error_handler,
// halide_custom_print). When the shared module is created, we set
// those variables to point to the global handlers in
// JITModule.cpp (e.g. error_handler_handler, print_handler).
// Those global handlers use the user_context passed in to call
// the right handler for this particular pipeline run. The
// user_context is just a pointer to a JITUserContext, which is a
// member of the JITFuncCallContext which we will declare now:
// Ensure the module is compiled.
compile_jit(target);
// This has to happen after a runtime has been compiled in compile_jit.
JITFuncCallContext jit_context(jit_handlers());
void *user_context_storage = &jit_context.jit_context;
JITCallArgs args(contents->inferred_args.size() + outputs.size());
prepare_jit_call_arguments(outputs, target, param_map,
&user_context_storage, false, args);
// The handlers in the jit_context default to the default handlers
// in the runtime of the shared module (e.g. halide_print_impl,
// default_trace). As an example, here's what happens with a
// halide_print call:
// 1) Before the pipeline runs, when the single shared runtime
// module is created, halide_custom_print in posix_print.cpp is
// set to print_handler in JITModule.cpp
// 2) When the jitted module is compiled, we tell llvm to resolve
// calls to halide_print to the halide_print in the shared module
// we made.
// 3) The user calls realize(), and the jitted code calls
// halide_print in the shared runtime.
// 4) halide_print calls the function pointer halide_custom_print,
// which is print_handler in JITModule.cpp
// 5) print_handler casts the user_context to a JITUserContext,
// then calls the function pointer member handlers.custom_print,
// which is either halide_print_impl in the runtime, or some other
// function set by Pipeline::set_custom_print.
// Errors are slightly different, in that we always override the
// default when jitting. We instead use ErrorBuffer::handler
// above (this was set in jit_context's constructor). When
// jit-compiled code encounters an error, it calls this handler,
// which just records the fact there was an error and what the
// message was, then returns back into jitted code. The jitted
// code cleans up and returns early with an exit code. We record
// this exit status below, then pass it to jit_context.finalize at
// the end of this function. If it's non-zero,
// jit_context.finalize passes the recorded error message to
// halide_runtime_error, which either calls abort() or throws an
// exception.
debug(2) << "Calling jitted function\n";
int exit_status = contents->jit_module.argv_function()(args.store);
debug(2) << "Back from jitted function. Exit status was " << exit_status << "\n";
// If we're profiling, report runtimes and reset profiler stats.
if (target.has_feature(Target::Profile)) {
JITModule::Symbol report_sym =
contents->jit_module.find_symbol_by_name("halide_profiler_report");
JITModule::Symbol reset_sym =
contents->jit_module.find_symbol_by_name("halide_profiler_reset");
if (report_sym.address && reset_sym.address) {
void *uc = &jit_context.jit_context;
void (*report_fn_ptr)(void *) = (void (*)(void *))(report_sym.address);
report_fn_ptr(uc);
void (*reset_fn_ptr)() = (void (*)())(reset_sym.address);
reset_fn_ptr();
}
}
jit_context.finalize(exit_status);
}
void Pipeline::infer_input_bounds(RealizationArg outputs, const ParamMap ¶m_map) {
Target target = get_jit_target_from_environment();
compile_jit(target);
// This has to happen after a runtime has been compiled in compile_jit.
JITFuncCallContext jit_context(jit_handlers());
void *user_context_storage = &jit_context.jit_context;
size_t args_size = contents->inferred_args.size() + outputs.size();
JITCallArgs args(args_size);
prepare_jit_call_arguments(outputs, target, param_map,
&user_context_storage, true, args);
struct TrackedBuffer {
// The query buffer, and a backup to check for changes. We
// want wrappers around actual buffer_ts so that we can copy
// the metadata, not shared pointers to a single buffer, so
// it's simpler to use the runtime buffer class.
Runtime::Buffer<> query, orig;
};
vector<TrackedBuffer> tracked_buffers(args_size);
vector<size_t> query_indices;
for (size_t i = 0; i < contents->inferred_args.size(); i++) {
if (args.store[i] == nullptr) {
query_indices.push_back(i);
InferredArgument ia = contents->inferred_args[i];
internal_assert(ia.param.defined() && ia.param.is_buffer());
// Make some empty Buffers of the right dimensionality
vector<int> initial_shape(ia.param.dimensions(), 0);
tracked_buffers[i].query = Runtime::Buffer<>(ia.param.type(), nullptr, initial_shape);
tracked_buffers[i].orig = Runtime::Buffer<>(ia.param.type(), nullptr, initial_shape);
args.store[i] = tracked_buffers[i].query.raw_buffer();
}
}
// No need to query if all the inputs are bound already.
if (query_indices.empty()) {
debug(1) << "All inputs are bound. No need for bounds inference\n";
return;
}
int iter = 0;
const int max_iters = 16;
for (iter = 0; iter < max_iters; iter++) {
// Make a copy of the buffers that might be mutated
for (TrackedBuffer &tb : tracked_buffers) {
// Make a copy of the buffer sizes, etc.
tb.orig = tb.query;
}
Internal::debug(2) << "Calling jitted function\n";
int exit_status = contents->jit_module.argv_function()(args.store);
jit_context.report_if_error(exit_status);
Internal::debug(2) << "Back from jitted function\n";
bool changed = false;
// Check if there were any changes
for (TrackedBuffer &tb : tracked_buffers) {
for (int i = 0; i < tb.query.dimensions(); i++) {
if (tb.query.dim(i).min() != tb.orig.dim(i).min() ||
tb.query.dim(i).extent() != tb.orig.dim(i).extent() ||
tb.query.dim(i).stride() != tb.orig.dim(i).stride()) {
changed = true;
}
}
}
if (!changed) {
break;
}
}
jit_context.finalize(0);
user_assert(iter < max_iters)
<< "Inferring input bounds on Pipeline"
<< " didn't converge after " << max_iters
<< " iterations. There may be unsatisfiable constraints\n";
debug(1) << "Bounds inference converged after " << iter << " iterations\n";
// Now allocate the resulting buffers
for (size_t i : query_indices) {
InferredArgument ia = contents->inferred_args[i];
Buffer<> *buf_out_param = nullptr;
Parameter &p = param_map.map(ia.param, buf_out_param);
if (&p != &ia.param) {
user_assert(buf_out_param != nullptr) << "Output Buffer<> arguments to infer_input_bounds in parameters map must be passed as pointers.\n";
}
internal_assert(!p.buffer().defined());
// Allocate enough memory with the right type and dimensionality.
tracked_buffers[i].query.allocate();
if (buf_out_param != nullptr) {
*buf_out_param = Buffer<>(*tracked_buffers[i].query.raw_buffer());
} else {
// Bind this parameter to this buffer, giving away the
// buffer. The user retrieves it via ImageParam::get.
p.set_buffer(Buffer<>(std::move(tracked_buffers[i].query)));
}
}
}
void Pipeline::infer_input_bounds(int x_size, int y_size, int z_size, int w_size,
const ParamMap ¶m_map) {
user_assert(defined()) << "Can't infer input bounds on an undefined Pipeline.\n";
vector<int> size;
if (x_size) size.push_back(x_size);
if (y_size) size.push_back(y_size);
if (z_size) size.push_back(z_size);
if (w_size) size.push_back(w_size);
vector<Buffer<>> bufs;
for (Type t : contents->outputs[0].output_types()) {
bufs.emplace_back(t, size);
}
Realization r(bufs);
infer_input_bounds(r, param_map);
}
void Pipeline::invalidate_cache() {
if (defined()) {
contents->invalidate_cache();
}
}
JITExtern::JITExtern(Pipeline pipeline)
: pipeline_(pipeline) {
}
JITExtern::JITExtern(Func func)
: pipeline_(func) {
}
JITExtern::JITExtern(const ExternCFunction &extern_c_function)
: extern_c_function_(extern_c_function) {
}
} // namespace Halide