/*
 * 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 "gprof.h"
#include "cg_arcs.h"
#include "core.h"
#include "hist.h"
#include "symtab.h"

/*
 * Opcodes of the call instructions:
 */
#define OP_Jxx	0x1a
#define	OP_BSR	0x34

#define Jxx_FUNC_JMP		0
#define Jxx_FUNC_JSR		1
#define Jxx_FUNC_RET		2
#define Jxx_FUNC_JSR_COROUTINE	3

typedef union {
    struct {
	unsigned other	 : 26;
	unsigned op_code :  6;
    } a;				/* any format */
    struct {
	signed	 disp	 : 21;
	unsigned ra	 :  5;
	unsigned op_code :  6;
    } b;				/* branch format */
    struct {
	signed	 hint	 : 14;
	unsigned func	 :  2;
	unsigned rb	 :  5;
	unsigned ra	 :  5;
	unsigned op_code :  6;
    } j;				/* jump format */
} Instruction;

static Sym indirect_child;


/*
 * On the Alpha we can only detect PC relative calls, which are
 * usually generated for calls to functions within the same
 * object file only.  This is still better than nothing, however.
 * (In particular it should be possible to find functions that
 *  potentially call integer division routines, for example.)
 */
void
find_call(parent, p_lowpc, p_highpc)
     Sym *parent;
     bfd_vma p_lowpc;
     bfd_vma p_highpc;
{
    static bfd_vma delta = 0;
    bfd_vma dest_pc;
    Instruction *pc;
    Sym *child;
    
    if (!delta) {
	delta = (bfd_vma) core_text_space - core_text_sect->vma;

	sym_init(&indirect_child);
	indirect_child.name = "<indirect child>";
	indirect_child.cg.prop.fract = 1.0;
	indirect_child.cg.cyc.head = &indirect_child;
    } /* if */
    
    if (!core_text_space) {
	return;
    } /* if */
    if (p_lowpc < s_lowpc) {
	p_lowpc = s_lowpc;
    } /* if */
    if (p_highpc > s_highpc) {
	p_highpc = s_highpc;
    } /* if */
    DBG(CALLDEBUG, printf("[find_call] %s: 0x%lx to 0x%lx\n",
			  parent->name, p_lowpc, p_highpc));
    for (pc = (Instruction*)(p_lowpc + delta);
	 pc < (Instruction*)(p_highpc + delta);
	 ++pc)
    {
	switch (pc->a.op_code) {
	  case OP_Jxx:
	    /*
	     * There is no simple and reliable way to determine the
	     * target of a jsr (the hint bits help, but there aren't
	     * enough bits to get a satisfactory hit rate).  Instead,
	     * for any indirect jump we simply add an arc from PARENT
	     * to INDIRECT_CHILD---that way the user it at least able
	     * to see that there are other calls as well.
	     */
	    if (pc->j.func == Jxx_FUNC_JSR
		|| pc->j.func == Jxx_FUNC_JSR_COROUTINE)
	    {
		DBG(CALLDEBUG,
		    printf("[find_call] 0x%lx: jsr%s <indirect_child>\n",
			   (bfd_vma) pc - delta,
			   pc->j.func == Jxx_FUNC_JSR ? "" : "_coroutine"));
		arc_add(parent, &indirect_child, 0);
	    } /* if */
	    break;

	  case OP_BSR:
	    DBG(CALLDEBUG,
		printf("[find_call] 0x%lx: bsr", (bfd_vma) pc - delta));
	    /*
	     * Regular PC relative addressing.  Check that this is the
	     * address of a function.  The linker sometimes redirects
	     * the entry point by 8 bytes to skip loading the global
	     * pointer, so we all for either address:
	     */
	    dest_pc = ((bfd_vma) (pc + 1 + pc->b.disp)) - delta;
	    if (dest_pc >= s_lowpc && dest_pc <= s_highpc) {
		child = sym_lookup(&symtab, dest_pc);
		DBG(CALLDEBUG,
		    printf(" 0x%lx\t; name=%s, addr=0x%lx",
			   dest_pc, child->name, child->addr));
		if (child->addr == dest_pc || child->addr == dest_pc - 8) {
		    DBG(CALLDEBUG, printf("\n"));
		    /* a hit:  */
		    arc_add(parent, child, 0);
		    continue;
		} /* if */
	    } /* if */
	    /*
	     * Something funny going on.
	     */
	    DBG(CALLDEBUG, printf("\tbut it's a botch\n"));
	    break;

	  default:
	    break;
	} /* switch */
    } /* for */
} /* find_call */
			/*** end of alpha.c ***/