ilive.c

CC386 is a general-purpose 32-bit C compiler. It is not an optimizing compiler but given that the co

/* 
Copyright 1994-2003 Free Software Foundation, Inc.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  

This program is derived from the cc68k complier by 
Matthew Brandt ([e-mail]) 

You may contact the author of this derivative at:

mailto::[e-mail]

or by snail mail at:

David Lindauer
850 Washburn Ave Apt 99
Louisville, KY 40222
 */
/*
 * ilive.c
 *
 * live variable analysis
 *
 */
#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <limits.h>
#include "utype.h"	
#include "cmdline.h"	
#include "lists.h"
#include "expr.h"
#include "c.h"
#include "iexpr.h"
#include "iopt.h"
#include "diag.h"

extern int global_flag;
extern int blocknum;
extern int *dfst;
extern BLOCKLIST **blockarray;
extern int pointer_count, source_count;
extern IMODE **pointerarray;
extern QUAD **sourcearray;
extern BYTE *temparray4;
extern int sourcebytes;
extern unsigned char bittab[8];

static int variable_count, variable_bytes;
static int max_variables;
static IMODE **usearray;
static BYTE *temparray3;

#ifdef DUMP_GCSE_INFO
    extern FILE *icdFile,  *outputFile;
    static void dumpvarset(BYTE *set, char *title)
    {
        int i;
        fprintf(icdFile, "\n;%s\n", title);
        for (i = 0; i < variable_count; i++)
        if (isset(set, i))
        {
            fprintf(icdFile, "; ");
            putamode(usearray[i]);
            fprintf(icdFile, "\n");
        }

    }
    static void dump_use(void)
    {
        int i;
        char buf[256];
        FILE *temp;
        if (!icdFile)
            return ;
        temp = outputFile;
        outputFile = icdFile;

        fprintf(icdFile, "\n; Used Variables: %d\n", variable_count);
        for (i = 0; i < variable_count; i++)
        {
            fprintf(icdFile, "; ");
            putamode(usearray[i]);
            fprintf(icdFile, "\n");
        }
        fprintf(icdFile, "\n; Sets:\n");
        for (i = 0; i < blocknum; i++)
        {
            sprintf(buf, "; def block %d", i + 1);
            dumpvarset(blockarray[i]->block->p_def, buf);
            sprintf(buf, "; use block %d", i + 1);
            dumpvarset(blockarray[i]->block->p_use, buf);
            sprintf(buf, "; live in block %d", i + 1);
            dumpvarset(blockarray[i]->block->p_live_in, buf);
            sprintf(buf, "; live out block %d", i + 1);
            dumpvarset(blockarray[i]->block->p_live_out, buf);
        }
        outputFile = temp;
    }
#endif 
static void enter_use(IMODE *var, int ans)
{
    if (var)
    {
        if (var->mode == i_ind || var->mode == i_direct && !ans)
        {
            int i;
            SYM *sp;
            if (var->offset->nodetype == en_labcon)
                return ;
            sp = varsp(var->offset);
            if (sp && sp->imvalue)
                var = sp->imvalue;
            if (var->useindx)
                return ;
            if (variable_count >= max_variables)
            {
                IMODE **newarray = oalloc(sizeof(IMODE*)*(max_variables += 256))
                    ;
                if (usearray)
                    memcpy(newarray, usearray, sizeof(QUAD*)*(max_variables -
                        256));
                usearray = newarray;
            }
            if (ans && var->mode == i_ind)
            {
                IMODE *oldvar = var;
                global_flag++;
                var = xalloc(sizeof(IMODE));
                global_flag--;
                *var =  *oldvar;
                var->mode = i_direct;
                if (sp)
                    sp->imvalue = var;
            }
            usearray[variable_count++] = var;
            var->useindx = variable_count;
        }
    }
}

//-------------------------------------------------------------------------

void RundownUse(void)
{
    int i;
    for (i = 0; i < variable_count; i++)
        usearray[i]->useindx = 0;
}

//-------------------------------------------------------------------------

static void CountUses(void)
{
    int block = 0, i, j, k;

    variable_count = 0;

    usearray = 0;

    max_variables = 0;

    for (i = 0; i < blocknum; i++)
    {
        BLOCK *l = blockarray[i]->block;
        QUAD *head = l->head;
        memcpy(temparray4, l->p_pin, sourcebytes *pointer_count);
        while (head && head->back != l->tail)
        {
            switch (head->dc.opcode)
            {
                case i_add:
                case i_sub:
                case i_udiv:
                case i_umod:
                case i_sdiv:
                case i_smod:
                case i_umul:
                case i_smul:
                case i_lsl:
                case i_lsr:
                case i_asl:
                case i_asr:
                case i_neg:
                case i_not:
                case i_and:
                case i_or:
                case i_eor:
                case i_setne:
                case i_sete:
                case i_setc:
                case i_seta:
                case i_setnc:
                case i_setbe:
                case i_setl:
                case i_setg:
                case i_setle:
                case i_setge:
                case i_assn:
                case i_coswitch:
                case i_jc:
                case i_ja:
                case i_je:
                case i_jnc:
                case i_jbe:
                case i_jne:
                case i_jl:
                case i_jg:
                case i_jle:
                case i_jge:
                case i_parm:
                    enter_use(head->dc.left, FALSE);
                    enter_use(head->dc.right, FALSE);
                    enter_use(head->ans, FALSE);
                    break;
                case i_gosub:
                    l->callcount++;
                    break;

            }
            ptrindex(head, l, temparray4);
            head = head->fwd;
        }
    }
}

//-------------------------------------------------------------------------

static void CreateUseBitArrays(void)
{
    int i;
    variable_bytes = (variable_count + 8) / 8;
    ;
    if (variable_bytes % 4)
        variable_bytes += 4-variable_bytes % 4;
    for (i = 0; i < blocknum; i++)
    {
        blockarray[i]->block->p_use = oalloc(variable_bytes);
        blockarray[i]->block->p_def = oalloc(variable_bytes);
        blockarray[i]->block->p_live_in = oalloc(variable_bytes);
        blockarray[i]->block->p_live_out = oalloc(variable_bytes);
    }
    temparray3 = oalloc(variable_bytes);
}

//-------------------------------------------------------------------------

static void use(IMODE *var, int *match, int *opposite)
{
    IMODE *xvar = 0;
    int i;
    SYM *sp;
    *match =  *opposite =  - 1;
    if (!var)
        return  - 1;
    if (var->mode != i_ind && var->mode != i_direct)
        return  - 1;
    if (var->offset->nodetype == en_labcon)
        return  - 1;
    sp = varsp(var->offset);
    if (var->mode == i_ind)
        xvar = sp->imvalue;
    else
        xvar = sp->imind;
    if (!xvar)
    {
        global_flag++;
        xvar = xalloc(sizeof(IMODE));
        global_flag--;
        *xvar =  *var;
        if (var->mode == i_ind)
        {
            xvar->mode = i_direct;
            if (sp)
                sp->imvalue = xvar;
        }
        else
        {
            xvar->mode = i_ind;
            if (sp)
                sp->imind = xvar;
        }
    }
    *match = var->useindx - 1;
    *opposite = xvar->useindx - 1;
    return ;
}

//-------------------------------------------------------------------------

static int use2(QUAD *var, int ans)
{
    int i;
    SYM *sp;
    IMODE *xvar;
    if (!((sp = varsp(var->dc.left->offset)) && var->dc.left->mode == i_immed))