Files
triton/lib/codegen/analysis/layout.cc
2019-10-10 15:52:03 -04:00

260 lines
8.1 KiB
C++

#include <algorithm>
#include <iostream>
#include <numeric>
#include "triton/codegen/analysis/axes.h"
#include "triton/codegen/analysis/align.h"
#include "triton/codegen/analysis/layout.h"
#include "triton/ir/function.h"
#include "triton/ir/module.h"
#include "triton/ir/utils.h"
namespace triton{
namespace codegen{
namespace analysis{
// constructor
layout::layout(analysis::axes *axes, analysis::align *align, size_t num_warps)
: axes_(axes), align_(align), num_warps_(num_warps) { }
// get group id
unsigned layout::layout_of(ir::value *value) const
{ return groups_.at(value); }
// get values
const std::vector<ir::value*>& layout::values_of(unsigned id) const
{ return values_.at(id); }
// get number of groups
size_t layout::num_layouts() const
{ return values_.size(); }
// connect two values
void layout::connect(ir::value *x, ir::value *y) {
if(x == y)
return;
if(!x->get_type()->is_tile_ty())
return;
if(!y->get_type()->is_tile_ty())
return;
std::vector<int> x_axes = axes_->get(x);
std::vector<int> y_axes = axes_->get(y);
std::set<int> sx_axes(x_axes.begin(), x_axes.end());
std::set<int> sy_axes(y_axes.begin(), y_axes.end());
std::set<int> common;
std::set_intersection(sx_axes.begin(), sx_axes.end(),
sy_axes.begin(), sy_axes.end(),
std::inserter(common, common.begin()));
if(!common.empty())
graph_.add_edge(x, y);
}
// make graph
void layout::make_graph(ir::instruction *i) {
for(ir::value* opx: i->ops())
for(ir::value* opy: i->ops()){
connect(i, opx);
connect(opx, opy);
}
}
// hmma
bool is_hmma_c(ir::value *v){
bool result = false;
if(auto *x = dynamic_cast<ir::dot_inst*>(v)){
ir::value *a = x->get_operand(0);
ir::type *a_ty = a->get_type();
ir::value *b = x->get_operand(1);
ir::type *b_ty = b->get_type();
result = a_ty->get_scalar_ty()->is_half_ty() &&
b_ty->get_scalar_ty()->is_half_ty();
}
return result;
}
const layout_t* layout::get(ir::value *v) const {
return layouts_.at(groups_.at(v));
}
std::map<size_t, layout_t*>& layout::get_all() {
return layouts_;
}
void extract_io_use(ir::value *v, std::set<ir::value*>& result) {
for(ir::user* u: v->get_users()){
auto i = dynamic_cast<ir::io_inst*>(u);
if(i && i->get_pointer_operand() == v)
result.insert(v);
}
}
inline bool is_trans(ir::value *v) {
if(dynamic_cast<ir::trans_inst *>(v)) {
return true;
}
if(auto *phi = dynamic_cast<ir::instruction *>(v)) {
bool result = true;
for(ir::value *op: phi->ops())
result = result && is_trans(op);
return result;
}
return false;
}
layout_t::layout_t(layout_type_t _type,
const std::vector<int> &_axes,
const std::vector<unsigned> &_shapes,
const std::vector<ir::value *> &values,
analysis::align* align): type(_type), axes(_axes), shapes(_shapes) {
// io pointer
std::set<ir::value*> ptr;
for(ir::value* v: values)
extract_io_use(v, ptr);
size_t rank = axes.size();
std::vector<int> order(rank);
std::iota(order.begin(), order.end(), 0);
for(ir::value *v: ptr){
auto max_contiguous = align->contiguous(v);
std::sort(order.begin(), order.end(), [&](unsigned a, unsigned b) {
return max_contiguous[a] > max_contiguous[b];
});
}
this->order = order;
}
inline unsigned clamp(unsigned x, unsigned lo, unsigned hi) {
return std::min(std::max(x, lo), hi);
}
layout_hmma_884_t::layout_hmma_884_t(size_t num_warps,
const std::vector<int>& _axes,
const std::vector<unsigned>& _shapes,
const std::vector<ir::value *> &values,
analysis::align* align): layout_t(HMMA_884, _axes, _shapes, values, align) {
unsigned shape_0 = shapes[order[0]];
unsigned shape_1 = shapes[order[1]];
/* fragments per warp */
// try to make things as square as possible to maximize data re-use
fpw = {1, 1, 1};
std::vector<int> fpw_nm1;
unsigned num_fragments = std::min<unsigned>((shape_0/8)*(shape_1/8), 4);
do {
fpw_nm1 = fpw;
if(fpw[0]*fpw[1] < num_fragments)
fpw[0] = clamp(fpw[0]*2, 1, shape_0 / 8);
if(fpw[0]*fpw[1] < num_fragments)
fpw[1] = clamp(fpw[1]*2, 1, shape_1 / 8);
}while(fpw_nm1 != fpw);
/* warps per tile */
// try to make things as square as possible to maximize data re-use
wpt = {1, 1, 1};
std::vector<int> wpt_nm1;
do{
wpt_nm1 = wpt;
if(wpt[0] * wpt[1] * wpt[2] < num_warps)
wpt[0] = clamp(wpt[0]*2, 1, shape_0 / (fpw[0]*8));
if(wpt[0] * wpt[1] * wpt[2] < num_warps)
wpt[1] = clamp(wpt[1]*2, 1, shape_1 / (fpw[1]*8));
}while(wpt_nm1 != wpt);
/* sanity check */
unsigned effective_num_warps = 1;
for(size_t d = 0; d < shapes.size(); d++)
effective_num_warps *= wpt[d];
if(num_warps != effective_num_warps)
throw std::runtime_error("cannot create a kernel with this amount of warps");
}
layout_scanline_t::layout_scanline_t(size_t num_warps,
const std::vector<int>& _axes,
const std::vector<unsigned>& _shapes,
const std::vector<ir::value *> &values,
analysis::align* align): layout_t(SCANLINE, _axes, _shapes, values, align){
unsigned size = std::accumulate(shapes.begin(), shapes.end(), 1, std::multiplies<int>());
unsigned num_threads = num_warps * 32;
nts.resize(shapes.size());
mts.resize(shapes.size());
unsigned i = order[0];
nts[i] = clamp(size / num_threads, 1, 4);
mts[i] = clamp(num_threads, 1, shapes[i] / nts[i]);
num_threads = num_threads / mts[i];
for(size_t d = 1; d < shapes.size(); d++){
i = order[d];
nts[i] = 1;
mts[i] = clamp(num_threads, 1, shapes[i]);
num_threads = num_threads / mts[i];
}
/* sanity check */
unsigned effective_num_threads = 1;
for(size_t d = 0; d < shapes.size(); d++)
effective_num_threads *= mts[d];
if(num_warps * 32 != effective_num_threads)
throw std::runtime_error("cannot create a kernel with this amount of warps");
}
void layout::run(ir::module &mod) {
// make graph
graph_.clear();
ir::for_each_instruction(mod, [this](ir::instruction* i) {
make_graph(i);
});
// connected components
graph_.connected_components(&values_, &groups_);
// create layouts
for(const auto& x: values_) {
bool hmma_c = std::any_of(x.second.begin(), x.second.end(), &is_hmma_c);
auto cmp = [](ir::value* x, ir::value *y) {
return x->get_type()->get_tile_ranks1() <
y->get_type()->get_tile_ranks1();
};
ir::value *largest = *std::max_element(x.second.begin(), x.second.end(), cmp);
const auto& axes = axes_->get(largest);
const auto& shapes = largest->get_type()->get_tile_shapes();
// type
if(hmma_c)
layouts_[x.first] = new layout_hmma_884_t(num_warps_, axes, shapes, x.second, align_);
else
layouts_[x.first] = new layout_scanline_t(num_warps_, axes, shapes, x.second, align_);
}
// matrix multiplication optimizations
for(const auto& x: values_) {
std::vector<ir::dot_inst*> dots;
for(ir::value* v: x.second)
if(auto *x = dynamic_cast<ir::dot_inst*>(v))
dots.push_back(x);
for(ir::dot_inst* dot: dots){
ir::value* a = dot->get_operand(0);
ir::value* b = dot->get_operand(1);
if(get(dot)->type == HMMA_884){
auto a_val = values_of(layout_of(a));
auto b_val = values_of(layout_of(b));
for(ir::value *v: a_val)
if(auto *cts = dynamic_cast<ir::copy_to_shared_inst*>(v))
layouts_[layout_of(a)]->order = layouts_[layout_of(cts->get_operand(0))]->order;
for(ir::value *v: b_val)
if(auto *cts = dynamic_cast<ir::copy_to_shared_inst*>(v))
layouts_[layout_of(b)]->order = layouts_[layout_of(cts->get_operand(0))]->order;
}
else{
std::vector<int> col = {0, 1};
std::vector<int> row = {1, 0};
layouts_[layout_of(a)]->order = is_trans(a) ? row : col;
layouts_[layout_of(b)]->order = is_trans(b) ? col : row;
}
}
}
}
}
}
}