path: root/gprof/cg_arcs.c

/*
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that: (1) source distributions retain this entire copyright
 * notice and comment, and (2) distributions including binaries display
 * the following acknowledgement:  ``This product includes software
 * developed by the University of California, Berkeley and its contributors''
 * in the documentation or other materials provided with the distribution
 * and in all advertising materials mentioning features or use of this
 * software. Neither the name of the University nor the names of its
 * contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
#include "libiberty.h"
#include "gprof.h"
#include "call_graph.h"
#include "cg_arcs.h"
#include "cg_dfn.h"
#include "cg_print.h"
#include "utils.h"
#include "sym_ids.h"

Sym *cycle_header;
int num_cycles;

/*
 * Return TRUE iff PARENT has an arc to covers the address
 * range covered by CHILD.
 */
Arc*
DEFUN(arc_lookup, (parent, child), Sym *parent AND Sym *child)
{
    Arc *arc;

    if (!parent || !child) {
	printf("[arc_lookup] parent == 0 || child == 0\n");
	return 0;
    } /* if */
    DBG(LOOKUPDEBUG, printf("[arc_lookup] parent %s child %s\n",
			    parent->name, child->name));
    for (arc = parent->cg.children; arc; arc = arc->next_child) {
	DBG(LOOKUPDEBUG, printf("[arc_lookup]\t parent %s child %s\n",
				arc->parent->name, arc->child->name));
	if (child->addr >= arc->child->addr
	    && child->end_addr <= arc->child->end_addr)
	{
	    return arc;
	} /* if */
    } /* for */
    return 0;
} /* arc_lookup */


/*
 * Add (or just increment) an arc:
 */
void
DEFUN(arc_add, (parent, child, count),
      Sym *parent AND Sym *child AND int count)
{
    Arc *arc;

    DBG(TALLYDEBUG, printf("[arc_add] %d arcs from %s to %s\n",
			   count, parent->name, child->name));
    arc = arc_lookup(parent, child);
    if (arc) {
	/*
	 * A hit: just increment the count.
	 */
	DBG(TALLYDEBUG, printf("[tally] hit %d += %d\n",
			       arc->count, count));
	arc->count += count;
	return;
    } /* if */
    arc = (Arc*)xmalloc(sizeof(*arc));
    arc->parent = parent;
    arc->child = child;
    arc->count = count;

    /* prepend this child to the children of this parent: */
    arc->next_child = parent->cg.children;
    parent->cg.children = arc;

    /* prepend this parent to the parents of this child: */
    arc->next_parent = child->cg.parents;
    child->cg.parents = arc;
} /* arc_add */


static int
DEFUN(cmp_topo, (lp, rp), const PTR lp AND const PTR rp)
{
    const Sym *left = *(const Sym **) lp;
    const Sym *right = *(const Sym **) rp;

    return left->cg.top_order - right->cg.top_order;
} /* cmp_topo */


static void
DEFUN(propagate_time, (parent), Sym *parent)
{
    Arc	*arc;
    Sym	*child;
    double share, prop_share;

    if (parent->cg.prop.fract == 0.0) {
	return;
    } /* if */

    /* gather time from children of this parent: */

    for (arc = parent->cg.children; arc; arc = arc->next_child) {
	child = arc->child;
	if (arc->count == 0 || child == parent || child->cg.prop.fract == 0) {
	    continue;
	} /* if */
	if (child->cg.cyc.head != child) {
	    if (parent->cg.cyc.num == child->cg.cyc.num) {
		continue;
	    } /* if */
	    if (parent->cg.top_order <= child->cg.top_order) {
		fprintf(stderr, "[propagate] toporder botches\n");
	    } /* if */
	    child = child->cg.cyc.head;
	} else {
	    if (parent->cg.top_order <= child->cg.top_order) {
		fprintf(stderr, "[propagate] toporder botches\n");
		continue;
	    } /* if */
	} /* if */
	if (child->ncalls == 0) {
	    continue;
	} /* if */

	/* distribute time for this arc: */
	arc->time = child->hist.time * (((double) arc->count)
					/ ((double) child->ncalls));
	arc->child_time = child->cg.child_time
	  * (((double) arc->count) / ((double) child->ncalls));
	share = arc->time + arc->child_time;
	parent->cg.child_time += share;

	/* (1 - cg.prop.fract) gets lost along the way: */
	prop_share = parent->cg.prop.fract * share;

	/* fix things for printing: */
	parent->cg.prop.child += prop_share;
	arc->time *= parent->cg.prop.fract;
	arc->child_time *= parent->cg.prop.fract;

	/* add this share to the parent's cycle header, if any: */
	if (parent->cg.cyc.head != parent) {
	    parent->cg.cyc.head->cg.child_time += share;
	    parent->cg.cyc.head->cg.prop.child += prop_share;
	} /* if */
	DBG(PROPDEBUG,
	    printf("[prop_time] child \t");
	    print_name(child);
	    printf(" with %f %f %d/%d\n", child->hist.time,
		   child->cg.child_time, arc->count, child->ncalls);
	    printf("[prop_time] parent\t");
	    print_name(parent);
	    printf("\n[prop_time] share %f\n", share));
    } /* for */
} /* propagate_time */


/*
 * Compute the time of a cycle as the sum of the times of all
 * its members.
 */
static void
DEFUN_VOID(cycle_time)
{
    Sym *member, *cyc;

    for (cyc = &cycle_header[1]; cyc <= &cycle_header[num_cycles]; ++cyc) {
	for (member = cyc->cg.cyc.next; member; member = member->cg.cyc.next) {
	    if (member->cg.prop.fract == 0.0) {
		/*
		 * All members have the same propfraction except those
		 * that were excluded with -E.
		 */
		continue;
	    } /* if */
	    cyc->hist.time += member->hist.time;
	} /* for */
	cyc->cg.prop.self = cyc->cg.prop.fract * cyc->hist.time;
    } /* for */
} /* cycle_time */


static void
DEFUN_VOID(cycle_link)
{
    Sym *sym, *cyc, *member;
    Arc *arc;
    int num;

    /* count the number of cycles, and initialize the cycle lists: */

    num_cycles = 0;
    for (sym = symtab.base; sym < symtab.limit; ++sym) {
	/* this is how you find unattached cycles: */
	if (sym->cg.cyc.head == sym && sym->cg.cyc.next) {
	    ++num_cycles;
	} /* if */
    } /* for */

    /*
     * cycle_header is indexed by cycle number: i.e. it is origin 1,
     * not origin 0.
     */
    cycle_header = (Sym*)xmalloc((num_cycles + 1) * sizeof(Sym));

    /*
     * Now link cycles to true cycle-heads, number them, accumulate
     * the data for the cycle.
     */
    num = 0; cyc = cycle_header;
    for (sym = symtab.base; sym < symtab.limit; ++sym) {
	if (!(sym->cg.cyc.head == sym && sym->cg.cyc.next != 0)) {
	    continue;
	} /* if */
	++num; ++cyc;
	sym_init(cyc);
	cyc->cg.print_flag = TRUE;	/* should this be printed? */
	cyc->cg.top_order = DFN_NAN;	/* graph call chain top-sort order */
	cyc->cg.cyc.num = num;		/* internal number of cycle on */
	cyc->cg.cyc.head = cyc;		/* pointer to head of cycle */
	cyc->cg.cyc.next = sym;		/* pointer to next member of cycle */
	DBG(CYCLEDEBUG, printf("[cycle_link] "); print_name(sym);
	    printf(" is the head of cycle %d\n", num));

	/* link members to cycle header: */
	for (member = sym; member; member = member->cg.cyc.next) { 
	    member->cg.cyc.num = num;
	    member->cg.cyc.head = cyc;
	} /* for */

	/*
	 * Count calls from outside the cycle and those among cycle
	 * members:
	 */
	for (member = sym; member; member = member->cg.cyc.next) {
	    for (arc = member->cg.parents; arc; arc = arc->next_parent) {
		if (arc->parent == member) {
		    continue;
		} /* if */
		if (arc->parent->cg.cyc.num == num) {
		    cyc->cg.self_calls += arc->count;
		} else {
		    cyc->ncalls += arc->count;
		} /* if */
	    } /* for */
	} /* for */
    } /* for */
} /* cycle_link */


/*
 * Check if any parent of this child (or outside parents of this
 * cycle) have their print flags on and set the print flag of the
 * child (cycle) appropriately.  Similarly, deal with propagation
 * fractions from parents.
 */
static void
DEFUN(inherit_flags, (child), Sym *child)
{
    Sym *head, *parent, *member;
    Arc *arc;

    head = child->cg.cyc.head;
    if (child == head) {
	/* just a regular child, check its parents: */
	child->cg.print_flag = FALSE;
	child->cg.prop.fract = 0.0;
	for (arc = child->cg.parents; arc; arc = arc->next_parent) {
	    parent = arc->parent;
	    if (child == parent) {
		continue;
	    } /* if */
	    child->cg.print_flag |= parent->cg.print_flag;
	    /*
	     * If the child was never actually called (e.g., this arc
	     * is static (and all others are, too)) no time propagates
	     * along this arc.
	     */
	    if (child->ncalls) {
		child->cg.prop.fract += parent->cg.prop.fract
		  * (((double) arc->count) / ((double) child->ncalls));
	    } /* if */
	} /* for */
    } else {
	/*
	 * Its a member of a cycle, look at all parents from outside
	 * the cycle.
	 */
	head->cg.print_flag = FALSE;
	head->cg.prop.fract = 0.0;
	for (member = head->cg.cyc.next; member; member = member->cg.cyc.next)
	{
	    for (arc = member->cg.parents; arc; arc = arc->next_parent) {
		if (arc->parent->cg.cyc.head == head) {
		    continue;
		} /* if */
		parent = arc->parent;
		head->cg.print_flag |= parent->cg.print_flag;
		/*
		 * If the cycle was never actually called (e.g. this
		 * arc is static (and all others are, too)) no time
		 * propagates along this arc.
		 */
		if (head->ncalls) {
		    head->cg.prop.fract += parent->cg.prop.fract
		      * (((double) arc->count) / ((double) head->ncalls));
		} /* if */
	    } /* for */
	} /* for */
	for (member = head; member; member = member->cg.cyc.next) {
	    member->cg.print_flag = head->cg.print_flag;
	    member->cg.prop.fract = head->cg.prop.fract;
	} /* for */
    } /* if */
} /* inherit_flags */


/*
 * In one top-to-bottom pass over the topologically sorted symbols
 * propagate:
 *	cg.print_flag as the union of parents' print_flags
 *	propfraction as the sum of fractional parents' propfractions
 * and while we're here, sum time for functions.
 */
static void
DEFUN(propagate_flags, (symbols), Sym **symbols)
{
    int index;
    Sym *old_head, *child;

    old_head = 0;
    for (index = symtab.len - 1; index >= 0; --index) {
	child = symbols[index];
	/*
	 * If we haven't done this function or cycle, inherit things
	 * from parent.  This way, we are linear in the number of arcs
	 * since we do all members of a cycle (and the cycle itself)
	 * as we hit the first member of the cycle.
	 */
	if (child->cg.cyc.head != old_head) {
	    old_head = child->cg.cyc.head;
	    inherit_flags(child);
	} /* if */
	DBG(PROPDEBUG,
	    printf("[prop_flags] ");
	    print_name(child);
	    printf("inherits print-flag %d and prop-fract %f\n",
		   child->cg.print_flag, child->cg.prop.fract));
	if (!child->cg.print_flag) {
	    /*
	     * Printflag is off. It gets turned on by being in the
	     * INCL_GRAPH table, or there being an empty INCL_GRAPH
	     * table and not being in the EXCL_GRAPH table.
	     */
	    if (sym_lookup(&syms[INCL_GRAPH], child->addr)
		|| (syms[INCL_GRAPH].len == 0
		    && !sym_lookup(&syms[EXCL_GRAPH], child->addr)))
	    {
		child->cg.print_flag = TRUE;
	    } /* if */
	} else {
	    /*
	     * This function has printing parents: maybe someone wants
	     * to shut it up by putting it in the EXCL_GRAPH table.
	     * (But favor INCL_GRAPH over EXCL_GRAPH.)
	     */
	    if (!sym_lookup(&syms[INCL_GRAPH], child->addr)
		&& sym_lookup(&syms[EXCL_GRAPH], child->addr))
	    {
		child->cg.print_flag = FALSE;
	    } /* if */
	} /* if */
	if (child->cg.prop.fract == 0.0) {
	    /*
	     * No parents to pass time to.  Collect time from children
	     * if its in the INCL_TIME table, or there is an empty
	     * INCL_TIME table and its not in the EXCL_TIME table.
	     */
	    if (sym_lookup(&syms[INCL_TIME], child->addr)
		|| (syms[INCL_TIME].len == 0
		    && !sym_lookup(&syms[EXCL_TIME], child->addr)))
	    {
		child->cg.prop.fract = 1.0;
	    } /* if */
	} else {
	    /*
	     * It has parents to pass time to, but maybe someone wants
	     * to shut it up by puttting it in the EXCL_TIME table.
	     * (But favor being in INCL_TIME tabe over being in
	     * EXCL_TIME table.)
	     */
	    if (!sym_lookup(&syms[INCL_TIME], child->addr)
		&& sym_lookup(&syms[EXCL_TIME], child->addr))
	    {
		child->cg.prop.fract = 0.0;
	    } /* if */
	} /* if */
	child->cg.prop.self = child->hist.time * child->cg.prop.fract;
	print_time += child->cg.prop.self;
	DBG(PROPDEBUG,
	    printf("[prop_flags] ");
	    print_name(child);
	    printf(" ends up with printflag %d and prop-fract %f\n",
		   child->cg.print_flag, child->cg.prop.fract);
	    printf("[prop_flags] time %f propself %f print_time %f\n",
		   child->hist.time, child->cg.prop.self, print_time));
    } /* if */
} /* propagate_flags */


/*
 * Compare by decreasing propagated time.  If times are equal, but one
 * is a cycle header, say that's first (e.g. less, i.e. -1).  If one's
 * name doesn't have an underscore and the other does, say that one is
 * first.  All else being equal, compare by names.
 */
static int
DEFUN(cmp_total, (lp, rp), const PTR lp AND const PTR rp)
{
    const Sym *left = *(const Sym**)lp;
    const Sym *right = *(const Sym**)rp;
    double diff;

    diff = (left->cg.prop.self + left->cg.prop.child)
      - (right->cg.prop.self + right->cg.prop.child);
    if (diff < 0.0) {
	return 1;
    } /* if */
    if (diff > 0.0) {
	return -1;
    } /* if */
    if (!left->name && left->cg.cyc.num != 0) {
	return -1;
    } /* if */
    if (!right->name && right->cg.cyc.num != 0) {
	return 1;
    } /* if */
    if (!left->name) {
	return -1;
    } /* if */
    if (!right->name) {
	return 1;
    } /* if */
    if (left->name[0] != '_' && right->name[0] == '_') {
	return -1;
    } /* if */
    if (left->name[0] == '_' && right->name[0] != '_') {
	return 1;
    } /* if */
    if (left->ncalls > right->ncalls) {
	return -1;
    } /* if */
    if (left->ncalls < right->ncalls) {
	return 1;
    } /* if */
    return strcmp(left->name, right->name);
} /* cmp_total */


/*
 * Topologically sort the graph (collapsing cycles), and propagates
 * time bottom up and flags top down.
 */
Sym**
DEFUN_VOID(cg_assemble)
{
    Sym *parent, **time_sorted_syms, **top_sorted_syms;
    long index;
    Arc *arc;
    extern void find_call PARAMS((Sym *parent,
				  bfd_vma p_lowpc, bfd_vma p_highpc));
    /*
     * initialize various things:
     *	    zero out child times.
     *	    count self-recursive calls.
     *	    indicate that nothing is on cycles.
     */
    for (parent = symtab.base; parent < symtab.limit; parent++) {
	parent->cg.child_time = 0.0;
	arc = arc_lookup(parent, parent);
	if (arc && parent == arc->child) {
	    parent->ncalls -= arc->count;
	    parent->cg.self_calls = arc->count;
	} else {
	    parent->cg.self_calls = 0;
	} /* if */
	parent->cg.prop.fract = 0.0;
	parent->cg.prop.self = 0.0;
	parent->cg.prop.child = 0.0;
	parent->cg.print_flag = FALSE;
	parent->cg.top_order = DFN_NAN;
	parent->cg.cyc.num = 0;
	parent->cg.cyc.head = parent;
	parent->cg.cyc.next = 0;
	if (ignore_direct_calls) {
	    find_call(parent, parent->addr, (parent+1)->addr);
	} /* if */
    } /* for */
    /*
     * Topologically order things.  If any node is unnumbered, number
     * it and any of its descendents.
     */
    for (parent = symtab.base; parent < symtab.limit; parent++) {
	if (parent->cg.top_order == DFN_NAN) {
	    cg_dfn(parent);
	} /* if */
    } /* for */

    /* link together nodes on the same cycle: */
    cycle_link();

    /* sort the symbol table in reverse topological order: */
    top_sorted_syms = (Sym**)xmalloc(symtab.len * sizeof(Sym*));
    for (index = 0; index < symtab.len; ++index) {
	top_sorted_syms[index] = &symtab.base[index];
    } /* for */
    qsort(top_sorted_syms, symtab.len, sizeof(Sym *), cmp_topo);
    DBG(DFNDEBUG,
	printf("[cg_assemble] topological sort listing\n");
	for (index = 0; index < symtab.len; ++index) {
	    printf("[cg_assemble] ");
	    printf("%d:", top_sorted_syms[index]->cg.top_order);
	    print_name(top_sorted_syms[index]);
	    printf("\n");
	} /* for */);
    /*
     * Starting from the topological top, propagate print flags to
     * children.  also, calculate propagation fractions.  this happens
     * before time propagation since time propagation uses the
     * fractions.
     */
    propagate_flags(top_sorted_syms);

    /*
     * Starting from the topological bottom, propogate children times
     * up to parents.
     */
    cycle_time();
    for (index = 0; index < symtab.len; ++index) {
	propagate_time(top_sorted_syms[index]);
    } /* for */

    free(top_sorted_syms);

    /*
     * Now, sort by CG.PROP.SELF + CG.PROP.CHILD.  Sorting both the regular
     * function names and cycle headers.
     */
    time_sorted_syms = (Sym**)xmalloc((symtab.len + num_cycles)*sizeof(Sym*));
    for (index = 0; index < symtab.len; index++) {
	time_sorted_syms[index] = &symtab.base[index];
    } /* if */
    for (index = 1; index <= num_cycles; index++) {
	time_sorted_syms[symtab.len + index - 1] = &cycle_header[index];
    } /* for */
    qsort(time_sorted_syms, symtab.len + num_cycles, sizeof(Sym*),
	  cmp_total);
    for (index = 0; index < symtab.len + num_cycles; index++) {
	time_sorted_syms[index]->cg.index = index + 1;
    } /* for */
    return time_sorted_syms;
} /* cg_assemble */

			/*** end of cg_arcs.c ***/