[libfirm] / ir / be / beprofile.c

/** vim: set sw=4 ts=4:
 * @file   beprofile.c
 * @date   2006-04-06
 * @author Adam M. Szalkowski
 * @cvs-id $Id$
 *
 * Code instrumentation and execution count profiling
 *
 * Copyright (C) 2006 Universitaet Karlsruhe
 * Released under the GPL
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <math.h>

#include "hashptr.h"
#include "debug.h"
#include "obst.h"
#include "set.h"
#include "list.h"
#include "pmap.h"

#include "entity.h"
#include "irprintf.h"
#include "irgwalk.h"
#include "irdump_t.h"
#include "irnode_t.h"
#include "ircons_t.h"
#include "irloop_t.h"
#include "iredges.h"
#include "execfreq.h"
#include "irvrfy.h"
#include "type.h"
#include "entity.h"

#include "be_t.h"
#include "belive_t.h"
#include "besched_t.h"
#include "beirgmod.h"
#include "bearch.h"
#include "beabi.h"
#include "benode_t.h"
#include "beutil.h"
#include "ircons.h"
#include "irhooks.h"
#include "iredges.h"

#include "bechordal_t.h"

#ifdef WITH_LIBCORE
#include <libcore/lc_opts.h>
#include <libcore/lc_opts_enum.h>
#endif /* WITH_LIBCORE */

#include "beprofile.h"

/** An entry in the id-to-location map */
typedef struct loc_entry {
        entity       *fname;   /**< the entity holding the file name */
        unsigned int lineno;   /**< line number */
} loc_entry;

typedef struct _block_id_walker_data_t {
        tarval         **array;    /**< the entity the holds the block counts */
        unsigned int   id;         /**< current block id number */
        ir_node        *symconst;  /**< the SymConst representing array */
        pmap           *fname_map; /**< set containing all found filenames */
        loc_entry      *locs;      /**< locations */
        ir_type        *tp_char;   /**< the character type */
        unsigned       flags;      /**< profile flags */
} block_id_walker_data_t;

typedef struct _execcount_t {
        unsigned int block;
        unsigned int count;
} execcount_t;

static int
cmp_execcount(const void * a, const void * b, size_t size)
{
        return ((execcount_t*)a)->block != ((execcount_t*)b)->block;
}

static void
block_counter(ir_node * bb, void * data)
{
        unsigned int  *count = data;
        *count = *count + 1;
}

static unsigned int
count_blocks(ir_graph * irg)
{
        unsigned int count = 0;

        irg_block_walk_graph(irg, block_counter, NULL, &count);
        return count;
}

/* keep the execcounts here because they are only read once per compiler run */
static set * profile = NULL;
static hook_entry_t hook;

/**
 * Instrument a block with code needed for profiling
 */
static void
instrument_block(ir_node * bb, ir_node * address, unsigned int id)
{
        ir_graph *irg = get_irn_irg(bb);
        ir_node  *start_block = get_irg_start_block(irg);
        ir_node  *load, *store, *offset, *add, *projm, *proji, *unknown;
        ir_node  *cnst;

        /**
         * We can't instrument the start and end block as there are no real
         * instructions in these blocks
         */
        if(bb == start_block || bb == get_irg_end_block(irg))
                return;

        unknown = new_r_Unknown(irg, mode_M);
        cnst    = new_r_Const_long(irg, start_block, mode_Iu, get_mode_size_bytes(mode_Iu) * id);
        offset  = new_r_Add(irg, bb, address, cnst, mode_P);
        load    = new_r_Load(irg, bb, unknown, offset, mode_Iu);
        projm   = new_r_Proj(irg, bb, load, mode_M, pn_Load_M);
        proji   = new_r_Proj(irg, bb, load, mode_Iu, pn_Load_res);
        cnst    = new_r_Const_long(irg, start_block, mode_Iu, 1);
        add     = new_r_Add(irg, bb, proji, cnst, mode_Iu);
        store   = new_r_Store(irg, bb, projm, offset, add);
        projm   = new_r_Proj(irg, bb, store, mode_M, pn_Store_M);
        set_irn_link(bb, projm);
        set_irn_link(projm, load);
}

typedef struct fix_env {
        ir_node *start_block;
        ir_node *end_block;
} fix_env;

/**
 * SSA Construction for instrumentation code memory
 */
static void
fix_ssa(ir_node * bb, void * data)
{
        fix_env *env = data;
        ir_node *mem;
        int     arity = get_Block_n_cfgpreds(bb);

        /* start and end block are not instrumented, skip! */
        if (bb == env->start_block || bb == env->end_block)
                return;

        if (arity == 1) {
                mem = get_irn_link(get_Block_cfgpred_block(bb, 0));
        } else {
                int n;
                ir_node **ins;
                ir_graph *irg = current_ir_graph;

                NEW_ARR_A(ir_node*, ins, arity);
                for (n = arity - 1; n >= 0; --n) {
                        ins[n] = get_irn_link(get_Block_cfgpred_block(bb, n));
                }
                mem = new_r_Phi(irg, bb, arity, ins, mode_M);
        }
        set_Load_mem(get_irn_link(get_irn_link(bb)), mem);
}


/**
 * Generates a new irg which calls the initializer
 *
 * Pseudocode:
 *       void __firmprof_initializer(void) { __init_firmprof(ent_filename, bblock_id, bblock_counts, n_blocks); }
 */
static ir_graph *
gen_initializer_irg(entity * ent_filename, entity * bblock_id, entity * bblock_counts, int n_blocks)
{
        ir_node *start_block;

        ir_node   *ins[4];
        ident     *name = new_id_from_str("__firmprof_initializer");
        entity    *ent  = new_entity(get_glob_type(), name, new_type_method(name, 0, 0));
        ir_node   *ret, *call, *symconst;
        symconst_symbol sym;

        ident     *init_name = new_id_from_str("__init_firmprof");
        ir_type   *init_type = new_type_method(init_name, 4, 0);
        ir_type   *uint, *uintptr, *string;
        entity    *init_ent;
        ir_graph  *irg;
        ir_node   *bb;
        ir_type   *empty_frame_type;

        set_entity_ld_ident(ent, name);

        uint    = new_type_primitive(new_id_from_str("__uint"), mode_Iu);
        uintptr = new_type_pointer(new_id_from_str("__uintptr"), uint, mode_P);
        string  = new_type_pointer(new_id_from_str("__charptr"), new_type_primitive(new_id_from_str("__char"), mode_Bs), mode_P);

        set_method_param_type(init_type, 0, string);
        set_method_param_type(init_type, 1, uintptr);
        set_method_param_type(init_type, 2, uintptr);
        set_method_param_type(init_type, 3, uint);
        init_ent = new_entity(get_glob_type(), init_name, init_type);
        set_entity_ld_ident(init_ent, init_name);

        irg = new_ir_graph(ent, 0);
        empty_frame_type = get_irg_frame_type(irg);
        set_type_size_bytes(empty_frame_type, 0);

        bb = get_cur_block();

        start_block = get_irg_start_block(irg);

        sym.entity_p = init_ent;
        symconst     = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);

        sym.entity_p = ent_filename;
        ins[0] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
        sym.entity_p = bblock_id;
        ins[1] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
        sym.entity_p = bblock_counts;
        ins[2] = new_r_SymConst(irg, start_block, sym, symconst_addr_ent);
        ins[3] = new_r_Const_long(irg, start_block, mode_Iu, n_blocks);

        call = new_r_Call(irg, bb, get_irg_initial_mem(irg), symconst, 4, ins, init_type);
        ret = new_r_Return(irg, bb, new_r_Proj(irg, bb, call, mode_M, pn_Call_M_regular), 0, NULL);
        mature_immBlock(bb);

        add_immBlock_pred(get_irg_end_block(irg), ret);
        mature_immBlock(get_irg_end_block(irg));

        irg_finalize_cons(irg);

        return irg;
}

/**
 * Create the location data for the given debug info.
 */
static void create_location_data(dbg_info *dbg, block_id_walker_data_t *wd)
{
        unsigned lineno;
        const char *fname = be_retrieve_dbg_info(dbg, &lineno);

        if (fname) {
                pmap_entry *entry = pmap_find(wd->fname_map, (void *)fname);
                entity     *ent;

                if (! entry) {
                        static unsigned nr = 0;
                        ident   *id;
                        char    buf[128];
                        ir_type *arr;
                        int     i, len = strlen(fname) + 1;
                        tarval  **tarval_string;

                        snprintf(buf, sizeof(buf), "firm_name_arr.%d", nr);
                        arr = new_type_array(new_id_from_str(buf), 1, wd->tp_char);
                        set_array_bounds_int(arr, 0, 0, len);

                        snprintf(buf, sizeof(buf), "__firm_name.%d", nr++);
                        id = new_id_from_str(buf);
                        ent = new_entity(get_glob_type(), id, arr);
                        set_entity_ld_ident(ent, id);

                        pmap_insert(wd->fname_map, (void *)fname, ent);

                        /* initialize file name string constant */
                        tarval_string = alloca(sizeof(*tarval_string) * (len));
                        for (i = 0; i < len; ++i) {
                                tarval_string[i] = new_tarval_from_long(fname[i], mode_Bs);
                        }
                        set_entity_variability(ent, variability_constant);
                        set_array_entity_values(ent, tarval_string, len);
                } else {
                        ent = entry->value;
                }
                wd->locs[wd->id].fname  = ent;
                wd->locs[wd->id].lineno = lineno;
        } else {
                wd->locs[wd->id].fname  = NULL;
                wd->locs[wd->id].lineno = 0;
        }
}

/**
 * Walker: assigns an ID to every block.
 * Builds the string table
 */
static void
block_id_walker(ir_node * bb, void * data)
{
        block_id_walker_data_t *wd = data;

        wd->array[wd->id] = new_tarval_from_long(get_irn_node_nr(bb), mode_Iu);
        instrument_block(bb, wd->symconst, wd->id);

        if (wd->flags & profile_with_locations) {
                dbg_info *dbg = get_irn_dbg_info(bb);
                create_location_data(dbg, wd);
        }
        ++wd->id;
}

#define IDENT(x)        new_id_from_chars(x, sizeof(x) - 1)

ir_graph *
be_profile_instrument(const char *filename, unsigned flags)
{
        int            n, i;
        unsigned int   n_blocks = 0;
        entity        *bblock_id, *bblock_counts, *ent_filename, *ent_locations,
                          *loc_lineno, *loc_name, *ent;
        ir_type       *array_type, *uint_type, *string_type, *character_type,
                          *loc_type, *charptr_type, *gtp;
        tarval       **tarval_array, **tarval_string, *tv;
        int            filename_len = strlen(filename)+1;
        ident         *cur_ident;
        int            align_l, align_n, size;
        ir_graph      *rem;

        block_id_walker_data_t  wd;
        symconst_symbol sym;

        /* count the number of block first */
        for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
                ir_graph *irg = get_irp_irg(n);

                n_blocks += count_blocks(irg);
        }

        /* create all the necessary types and entities. Note that the
           types must have a fixed layout, because we already running in the
           backend */
        uint_type      = new_type_primitive(IDENT("__uint"), mode_Iu);
        set_type_alignment_bytes(uint_type, get_type_size_bytes(uint_type));
        array_type     = new_type_array(IDENT("__block_info_array"), 1, uint_type);
        set_array_bounds_int(array_type, 0, 0, n_blocks);

        character_type = new_type_primitive(IDENT("__char"), mode_Bs);
        string_type    = new_type_array(IDENT("__filename"), 1, character_type);
        set_array_bounds_int(string_type, 0, 0, filename_len);

        gtp            = get_glob_type();

        cur_ident      = IDENT("__FIRMPROF__BLOCK_IDS");
        bblock_id      = new_entity(gtp, cur_ident, array_type);
        set_entity_ld_ident(bblock_id, cur_ident);
        set_entity_variability(bblock_id, variability_initialized);

        cur_ident      = IDENT("__FIRMPROF__BLOCK_COUNTS");
        bblock_counts  = new_entity(gtp, cur_ident, array_type);
        set_entity_ld_ident(bblock_counts, cur_ident);
        set_entity_variability(bblock_counts, variability_initialized);

        cur_ident      = IDENT("__FIRMPROF__FILE_NAME");
        ent_filename   = new_entity(gtp, cur_ident, string_type);
        set_entity_ld_ident(ent_filename, cur_ident);

        if (flags & profile_with_locations) {
                loc_type       = new_type_struct(IDENT("__location"));
                loc_lineno     = new_entity(loc_type, IDENT("lineno"), uint_type);
                align_l        = get_type_alignment_bytes(uint_type);
                size           = get_type_size_bytes(uint_type);
                set_entity_offset_bytes(loc_lineno, 0);

                charptr_type   = new_type_pointer(IDENT("__charptr"), character_type, mode_P_data);
                align_n        = get_type_size_bytes(charptr_type);
                set_type_alignment_bytes(charptr_type, align_n);
                loc_name       = new_entity(loc_type, IDENT("name"), charptr_type);
                size           = (size + align_n - 1) & -align_n;
                set_entity_offset_bytes(loc_name, size);
                size          += align_n;

                if (align_n > align_l)
                        align_l = align_n;
                size = (size + align_l - 1) & -align_l;
                set_type_size_bytes(loc_type, size);
                set_type_state(loc_type, layout_fixed);

                loc_type = new_type_array(IDENT("__locarray"), 1, loc_type);
                set_array_bounds_int(string_type, 0, 0, n_blocks);

                cur_ident      = IDENT("__FIRMPROF__LOCATIONS");
                ent_locations   = new_entity(gtp, cur_ident, loc_type);
                set_entity_ld_ident(ent_locations, cur_ident);
        }

        /* initialize count array */
        NEW_ARR_A(tarval *, tarval_array, n_blocks);
        tv = get_tarval_null(mode_Iu);
        for (i = 0; i < n_blocks; ++i) {
                tarval_array[i] = tv;
        }
        set_array_entity_values(bblock_counts, tarval_array, n_blocks);

        /* initialize function name string constant */
        tarval_string = alloca(sizeof(*tarval_string) * (filename_len));
        for (i = 0; i < filename_len; ++i) {
                tarval_string[i] = new_tarval_from_long(filename[i], mode_Bs);
        }
        set_entity_variability(ent_filename, variability_constant);
        set_array_entity_values(ent_filename, tarval_string, filename_len);

        /* initialize block id array and instrument blocks */
        wd.array     = tarval_array;
        wd.id        = 0;
        wd.tp_char   = character_type;
        wd.flags     = flags;
        if (flags & profile_with_locations) {
                wd.fname_map = pmap_create();
                NEW_ARR_A(loc_entry, wd.locs, n_blocks);
        }

        for (n = get_irp_n_irgs() - 1; n >= 0; --n) {
                ir_graph      *irg = get_irp_irg(n);
                int            i;
                ir_node       *endbb = get_irg_end_block(irg);
                fix_env       env;

                set_current_ir_graph(irg);

                /* generate a symbolic constant pointing to the count array */
                sym.entity_p = bblock_counts;
                wd.symconst  = new_r_SymConst(irg, get_irg_start_block(irg), sym, symconst_addr_ent);

                irg_block_walk_graph(irg, block_id_walker, NULL, &wd);
                env.start_block = get_irg_start_block(irg);
                env.end_block   = get_irg_end_block(irg);
                set_irn_link(env.start_block, get_irg_no_mem(irg));
                irg_block_walk_graph(irg, fix_ssa, NULL, &env);
                for (i = get_Block_n_cfgpreds(endbb) - 1; i >= 0; --i) {
                        ir_node *node = skip_Proj(get_Block_cfgpred(endbb, i));
                        ir_node *bb   = get_Block_cfgpred_block(endbb, i);
                        ir_node *sync;
                        ir_node *ins[2];

                        switch (get_irn_opcode(node)) {
                        case iro_Return:
                                ins[0] = get_irn_link(bb);
                                ins[1] = get_Return_mem(node);
                                sync   = new_r_Sync(irg, bb, 2, ins);
                                set_Return_mem(node, sync);
                                break;
                        case iro_Raise:
                                ins[0] = get_irn_link(bb);
                                ins[1] = get_Raise_mem(node);
                                sync   = new_r_Sync(irg, bb, 2, ins);
                                set_Raise_mem(node, sync);
                                break;
                        default:
                                /* a fragile's op exception. There should be another path to End,
                                   so ignore it */
                                assert(is_fragile_op(node) && "unexpected End control flow predecessor");
                        }
                }
        }
        set_array_entity_values(bblock_id, tarval_array, n_blocks);

        if (flags & profile_with_locations) {
                /* build the initializer for the locations */
                rem = current_ir_graph;
                current_ir_graph = get_const_code_irg();
                ent = get_array_element_entity(loc_type);
                set_entity_variability(ent_locations, variability_constant);
                for (i = 0; i < n_blocks; ++i) {
                        compound_graph_path *path;
                        tarval *tv;
                        ir_node *n;

                        /* lineno */
                        path = new_compound_graph_path(loc_type, 2);
                        set_compound_graph_path_array_index(path, 0, i);
                        set_compound_graph_path_node(path, 0, ent);
                        set_compound_graph_path_node(path, 1, loc_lineno);
                        tv = new_tarval_from_long(wd.locs[i].lineno, mode_Iu);
                        add_compound_ent_value_w_path(ent_locations, new_Const(mode_Iu, tv), path);

                        /* name */
                        path = new_compound_graph_path(loc_type, 2);
                        set_compound_graph_path_array_index(path, 0, i);
                        set_compound_graph_path_node(path, 0, ent);
                        set_compound_graph_path_node(path, 1, loc_name);
                        if (wd.locs[i].fname) {
                                sym.entity_p = wd.locs[i].fname;
                                n = new_SymConst(sym, symconst_addr_ent);
                        } else {
                                n = new_Const(mode_P_data, get_mode_null(mode_P_data));
                        }
                        add_compound_ent_value_w_path(ent_locations, n, path);
                }
                pmap_destroy(wd.fname_map);
        }
        return gen_initializer_irg(ent_filename, bblock_id, bblock_counts, n_blocks);
}

static void
profile_node_info(void *ctx, FILE *f, const ir_node *irn)
{
        if(is_Block(irn)) {
                fprintf(f, "profiled execution count: %u\n", be_profile_get_block_execcount(irn));
        }
}

static void
register_vcg_hook(void)
{
        memset(&hook, 0, sizeof(hook));
        hook.hook._hook_node_info = profile_node_info;
        register_hook(hook_node_info, &hook);
}

static void
unregister_vcg_hook(void)
{
        unregister_hook(hook_node_info, &hook);
}

/**
 * Reads the corresponding profile info file if it exists and returns a
 * profile info struct
 */
void
be_profile_read(const char *filename)
{
        FILE   *f;
        char    buf[8];
        size_t  ret;

        f = fopen(filename, "r");
        if(f == NULL) {
                return;
        }
        printf("found profile data '%s'.\n", filename);

        /* check magic */
        ret = fread(buf, 8, 1, f);
        if(ret == 0 || strncmp(buf, "firmprof", 8) != 0) {
                return;
        }

        if(profile) be_profile_free();
        profile = new_set(cmp_execcount, 16);

        do {
                execcount_t  query;
                ret = fread(&query, sizeof(unsigned int), 2, f);

                if(ret != 2) break;

                set_insert(profile, &query, sizeof(query), query.block);
        } while(1);

        fclose(f);
        register_vcg_hook();
}

/**
 * Frees the profile info
 */
void
be_profile_free(void)
{
        if(profile) {
                unregister_vcg_hook();
                del_set(profile);
        }
}

/**
 * Tells whether profile module has acquired data
 */
int
be_profile_has_data(void)
{
        return (profile != NULL);
}

/**
 * Get block execution count as determined be profiling
 */
unsigned int
be_profile_get_block_execcount(const ir_node *block)
{
        execcount_t *ec, query;

        if(!profile)
                return 1;

        query.block = get_irn_node_nr(block);
        ec = set_find(profile, &query, sizeof(query), get_irn_node_nr(block));

        if(ec != NULL) {
                return ec->count;
        } else {
                ir_fprintf(stderr, "Warning: Profile contains no data for %+F\n",
                           block);
                return 1;
        }
}

typedef struct _intialize_execfreq_env_t {
        ir_graph *irg;
        exec_freq_t *execfreqs;
        double freq_factor;
} initialize_execfreq_env_t;

// minimal execution frequency (an execfreq of 0 confuses algos)
static const double MIN_EXECFREQ = 0.00001;

static void initialize_execfreq(ir_node *block, void *data) {
        initialize_execfreq_env_t *env = data;
        double freq;

        if(block == get_irg_start_block(env->irg)
           || block == get_irg_end_block(env->irg)) {
                freq = 1.0;
        } else {
                freq = be_profile_get_block_execcount(block);
                freq *= env->freq_factor;
                if(freq < MIN_EXECFREQ)
                        freq = MIN_EXECFREQ;
        }

        set_execfreq(env->execfreqs, block, freq);
}

exec_freq_t *be_create_execfreqs_from_profile(ir_graph *irg)
{
        ir_node *block2 = NULL;
        ir_node *start_block;
        const ir_edge_t *edge;
        initialize_execfreq_env_t env;
        unsigned count;

        env.irg = irg;
        env.execfreqs = create_execfreq(irg);

        // find the successor to the start block
        start_block = get_irg_start_block(irg);
        foreach_block_succ(start_block, edge) {
                ir_node *succ = get_edge_src_irn(edge);
                if(succ != start_block) {
                        block2 = succ;
                        break;
                }
        }
        assert(block2 != NULL);

        count = be_profile_get_block_execcount(block2);
        if(count == 0) {
                // the function was never executed, so fallback to estimated freqs
                free_execfreq(env.execfreqs);

                return compute_execfreq(irg, 10);
        }

        env.freq_factor = 1.0 / count;
        irg_block_walk_graph(irg, initialize_execfreq, NULL, &env);

        return env.execfreqs;
}