Files
triton/lib/codegen/buffer_info.cpp
2019-02-24 14:35:16 -05:00

81 lines
2.3 KiB
C++

#include "triton/codegen/buffer_info.h"
#include "triton/ir/module.h"
#include "triton/ir/function.h"
#include "triton/ir/basic_block.h"
#include "triton/ir/instructions.h"
#include "triton/ir/type.h"
namespace triton {
namespace codegen{
// run pass on module
bool buffer_info_pass::is_loop_latch(ir::phi_node *phi, ir::value *terminator){
if(auto *br = dynamic_cast<ir::cond_branch_inst*>(terminator))
return br->get_true_dest() == phi->get_parent()
|| br->get_false_dest() == phi->get_parent();
else if(auto *br = dynamic_cast<ir::uncond_branch_inst*>(terminator))
return br->get_dest() == phi->get_parent();
else
throw std::runtime_error("unreachable");
}
void buffer_info_pass::run(ir::module &mod) {
// Find which buffers are shared
for(ir::function *fn: mod.get_function_list())
for(ir::basic_block *block: fn->blocks())
for(ir::instruction *i: block->get_inst_list())
if(dynamic_cast<ir::matmul_inst*>(i)){
shared_.insert(i->get_operand(0));
shared_.insert(i->get_operand(1));
}
// Handles phi nodes
for(ir::function *fn: mod.get_function_list())
for(ir::basic_block *block: fn->blocks())
for(ir::instruction *i: block->get_inst_list()) {
if(!i->get_type()->is_tile_ty())
continue;
// handle phi
if(auto *phi = dynamic_cast<ir::phi_node*>(i))
if(is_shared(phi)){
// determine if the value is in shared memory
bool is_double = false;
for(unsigned n = 0; n < phi->get_num_incoming(); n++){
ir::basic_block *inc_block = phi->get_incoming_block(n);
ir::value *terminator = inc_block->get_inst_list().back();
is_double = is_double || is_loop_latch(phi, terminator);
}
// add to double-buffered
if(is_double)
double_.insert(phi);
// set references of input
for(unsigned n = 0; n < phi->get_num_incoming(); n++){
ir::value *inc_val = phi->get_incoming_value(n);
refs_[inc_val] = phi;
}
}
}
for(auto &ref: refs_)
shared_.insert(ref.first);
}
// query double-buffered status
bool buffer_info_pass::is_double(ir::value *x)
{ return double_.find(x) != double_.end(); }
// query shared status
bool buffer_info_pass::is_shared(ir::value *x)
{ return shared_.find(x) != shared_.end(); }
// get reference if any
ir::value *buffer_info_pass::get_reference(ir::value *x)
{ return refs_[x]; }
}
}