path: root/src/cuda-sim/ptx-stats.cc

// Copyright (c) 2009-2011, Wilson W.L. Fung, Tor M. Aamodt
// The University of British Columbia
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
// Redistributions in binary form must reproduce the above copyright notice, this
// list of conditions and the following disclaimer in the documentation and/or
// other materials provided with the distribution.
// Neither the name of The University of British Columbia nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
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#include "ptx_ir.h"
#include "ptx_sim.h"
#include "ptx-stats.h"
#include "../option_parser.h"
#include <stdio.h>
#include <map>
#include "../tr1_hash_map.h"

// options
bool enable_ptx_file_line_stats;
char * ptx_line_stats_filename = NULL;

void ptx_file_line_stats_options(option_parser_t opp)
{
    option_parser_register(opp, "-enable_ptx_file_line_stats", OPT_BOOL, 
                           &enable_ptx_file_line_stats, 
                           "Turn on PTX source line statistic profiling. (1 = On)", "1");
    option_parser_register(opp, "-ptx_line_stats_filename", OPT_CSTR, 
                           &ptx_line_stats_filename, 
                           "Output file for PTX source line statistics.", "gpgpu_inst_stats.txt");
}

// implementations

// defining a PTX source line = filename + line number
class ptx_file_line 
{
public:
    ptx_file_line(const char* s, int l) {
        if( s == NULL ) 
            st = "NULL_NAME";
        else 
            st = s;
        line = l;
    }

    bool operator<(const ptx_file_line &other) const {
        if( st == other.st ) {
            if( line < other.line ) 
                return true;
            else
                return false; 
        } else {
            return st < other.st;
        }
    }

    bool operator==(const ptx_file_line &other) const {
        return (line==other.line) && (st==other.st);
    }

    std::string st;
    unsigned line;
};

// holds all statistics collected for a singe PTX source line
class ptx_file_line_stats
{
public:
    ptx_file_line_stats() 
        : exec_count(0), latency(0), dram_traffic(0), 
          smem_n_way_bank_conflict_total(0), smem_warp_count(0),
          gmem_n_access_total(0), gmem_warp_count(0), exposed_latency(0),
          warp_divergence(0)
    { }
    
    unsigned long exec_count;
    unsigned long long latency;
    unsigned long long dram_traffic;
    unsigned long long smem_n_way_bank_conflict_total;  // total number of banks accessed by this instruction
    unsigned long smem_warp_count;                      // number of warps accessing shared memory
    unsigned long long gmem_n_access_total; // number of uncoalesced access in total from this instruction
    unsigned long gmem_warp_count;          // number of warps causing these uncoalesced access
    unsigned long long exposed_latency; // latency exposed as pipeline bubbles (attributed to this instruction)
    unsigned long long warp_divergence; // number of warp divergence occured at this instruction
};

#if (tr1_hash_map_ismap == 1)
typedef tr1_hash_map<ptx_file_line, ptx_file_line_stats> ptx_file_line_stats_map_t;
#else
struct hash_ptx_file_line
{
    std::size_t operator()(const ptx_file_line & pfline) const {
        std::hash<unsigned> hash_line;
        return hash_line(pfline.line);
    }
};
typedef tr1_hash_map<ptx_file_line, ptx_file_line_stats, hash_ptx_file_line> ptx_file_line_stats_map_t;
#endif

static ptx_file_line_stats_map_t ptx_file_line_stats_tracker;

// output statistics to a file
void ptx_file_line_stats_write_file()
{
    // check if stat collection is turned on
    if (enable_ptx_file_line_stats == 0) return;

    ptx_file_line_stats_map_t::iterator it;
    FILE * pfile;

    pfile = fopen(ptx_line_stats_filename, "w");
    fprintf(pfile,"kernel line : count latency dram_traffic smem_bk_conflicts smem_warp gmem_access_generated gmem_warp exposed_latency warp_divergence\n");
    for( it=ptx_file_line_stats_tracker.begin(); it != ptx_file_line_stats_tracker.end(); it++ ) {
        fprintf(pfile, "%s %i : ", it->first.st.c_str(), it->first.line);
        fprintf(pfile, "%lu ", it->second.exec_count);
        fprintf(pfile, "%llu ", it->second.latency);
        fprintf(pfile, "%llu ", it->second.dram_traffic);
        fprintf(pfile, "%llu ", it->second.smem_n_way_bank_conflict_total);
        fprintf(pfile, "%lu ", it->second.smem_warp_count);
        fprintf(pfile, "%llu ", it->second.gmem_n_access_total);
        fprintf(pfile, "%lu ", it->second.gmem_warp_count);
        fprintf(pfile, "%llu ", it->second.exposed_latency);
        fprintf(pfile, "%llu ", it->second.warp_divergence);
        fprintf(pfile, "\n");
    }
    fflush(pfile);
    fclose(pfile);
}

// attribute one more execution count to this ptx instruction
// counting the number of threads (not warps) executing this instruction
void ptx_file_line_stats_add_exec_count(const ptx_instruction *pInsn)
{
    ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())].exec_count += 1;
}

// attribute pipeline latency to this ptx instruction (specified by the pc)
// pipeline latency is the number of cycles a warp with this instruction spent in the pipeline
void ptx_file_line_stats_add_latency(unsigned pc, unsigned latency)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);
    
    ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())].latency += latency;
}

// attribute dram traffic to this ptx instruction (specified by the pc)
// dram traffic is counted in number of requests 
void ptx_file_line_stats_add_dram_traffic(unsigned pc, unsigned dram_traffic)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);
    
    ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())].dram_traffic += dram_traffic;
}

// attribute the number of shared memory access cycles to a ptx instruction
// counts both the number of warps doing shared memory access and the number of cycles involved
void ptx_file_line_stats_add_smem_bank_conflict(unsigned pc, unsigned n_way_bkconflict)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);
    
    ptx_file_line_stats& line_stats = ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())];
    line_stats.smem_n_way_bank_conflict_total += n_way_bkconflict;
    line_stats.smem_warp_count += 1;
}

// attribute a non-coalesced mem access to a ptx instruction 
// counts both the number of warps causing this and the number of memory requests generated
void ptx_file_line_stats_add_uncoalesced_gmem(unsigned pc, unsigned n_access)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);
    
    ptx_file_line_stats& line_stats = ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())];
    line_stats.gmem_n_access_total += n_access;
    line_stats.gmem_warp_count += 1;
}

// a class that tracks the inflight memory instructions of a shader core 
// and attributes exposed latency to those instructions when signaled to do so 
class ptx_inflight_memory_insn_tracker
{
public:
    typedef std::map<const ptx_instruction *, int> insn_count_map;

    void add_count(const ptx_instruction * pInsn, int count = 1)
    {
        ptx_inflight_memory_insns[pInsn] += count;
    }

    void sub_count(const ptx_instruction * pInsn, int count = 1)
    {
        insn_count_map::iterator i_insncount; 
        i_insncount = ptx_inflight_memory_insns.find(pInsn);

        assert(i_insncount != ptx_inflight_memory_insns.end());

        i_insncount->second -= count;

        if (i_insncount->second <= 0) {
            ptx_inflight_memory_insns.erase(i_insncount);
        }
    }

    void attribute_exposed_latency(int count = 1)
    {
        insn_count_map &exlat_insnmap = ptx_inflight_memory_insns;
        insn_count_map::const_iterator i_exlatinsn;

        i_exlatinsn = exlat_insnmap.begin();
        for (; i_exlatinsn != exlat_insnmap.end(); ++i_exlatinsn) {
            const ptx_instruction *pInsn = i_exlatinsn->first;
            ptx_file_line_stats& line_stats = ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())];
            line_stats.exposed_latency += count;
        }
    }

    insn_count_map ptx_inflight_memory_insns;
};

static ptx_inflight_memory_insn_tracker *inflight_mem_tracker = NULL;

void ptx_file_line_stats_create_exposed_latency_tracker(int n_shader_cores)
{
    inflight_mem_tracker = new ptx_inflight_memory_insn_tracker[n_shader_cores];
}

// add an inflight memory instruction
void ptx_file_line_stats_add_inflight_memory_insn(int sc_id, unsigned pc)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);

    inflight_mem_tracker[sc_id].add_count(pInsn);
}

// remove an inflight memory instruction
void ptx_file_line_stats_sub_inflight_memory_insn(int sc_id, unsigned pc)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);

    inflight_mem_tracker[sc_id].sub_count(pInsn);
}

// attribute an empty cycle in the pipeline (exposed latency) to the ptx memory instructions in flight
void ptx_file_line_stats_commit_exposed_latency(int sc_id, int exposed_latency)
{
    assert(exposed_latency > 0);
    inflight_mem_tracker[sc_id].attribute_exposed_latency(exposed_latency);
}

// attribute the number of warp divergence to a ptx instruction
void ptx_file_line_stats_add_warp_divergence(unsigned pc, unsigned n_way_divergence)
{
    const ptx_instruction *pInsn = function_info::pc_to_instruction(pc);
    
    ptx_file_line_stats& line_stats = ptx_file_line_stats_tracker[ptx_file_line(pInsn->source_file(), pInsn->source_line())];
    line_stats.warp_divergence += n_way_divergence;
}