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/*
* Copyright (c) 2002-2005 The TenDRA Project <http://www.tendra.org/>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of The TenDRA Project 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 BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id$
*/
/*
Crown Copyright (c) 1997
This TenDRA(r) Computer Program is subject to Copyright
owned by the United Kingdom Secretary of State for Defence
acting through the Defence Evaluation and Research Agency
(DERA). It is made available to Recipients with a
royalty-free licence for its use, reproduction, transfer
to other parties and amendment for any purpose not excluding
product development provided that any such use et cetera
shall be deemed to be acceptance of the following conditions:-
(1) Its Recipients shall ensure that this Notice is
reproduced upon any copies or amended versions of it;
(2) Any amended version of it shall be clearly marked to
show both the nature of and the organisation responsible
for the relevant amendment or amendments;
(3) Its onward transfer from a recipient to another
party shall be deemed to be that party's acceptance of
these conditions;
(4) DERA gives no warranty or assurance as to its
quality or suitability for any purpose and DERA accepts
no liability whatsoever in relation to any use to which
it may be put.
*/
/* 80x86/inlinechoice.c */
/**********************************************************************
$Author: release $
$Date: 1998/01/17 15:55:51 $
$Revision: 1.1.1.1 $
$Log: inlinechoice.c,v $
* Revision 1.1.1.1 1998/01/17 15:55:51 release
* First version to be checked into rolling release.
*
* Revision 1.8 1996/12/04 17:58:36 pwe
* correct to allow inlining at >1 location
*
* Revision 1.7 1995/09/28 12:45:17 pwe
* tidy for tcc
*
* Revision 1.6 1995/08/04 08:29:20 pwe
* 4.0 general procs implemented
*
* Revision 1.5 1995/02/22 13:34:31 pwe
* no inline if application shape differs from return shape of proc
*
* Revision 1.4 1995/01/30 12:56:15 pwe
* Ownership -> PWE, tidy banners
*
**********************************************************************/
#include "config.h"
#include "common_types.h"
#include "installglob.h"
#include "exp.h"
#include "expmacs.h"
#include "tags.h"
#include "flags.h"
#include "shapemacs.h"
#include "inl_norm.h"
#define crit_inline 300
#define crit_decs 5
#define crit_decsatapp 5
#define apply_cost 3
static int complexity(exp e, int count, int newdecs);
static last_new_decs = -999;
/*
APPLY COMPLEXITY TO A LIST OF EXPRESSIONS
*/
int sbl
(exp e, int count, int newdecs)
{
int c = complexity(e, count, newdecs);
if (c < 0) return(c);
if (last(e)) return(c);
return(sbl(bro(e), c, newdecs));
}
/*
FIND THE COMPLEXITY OF AN EXPRESSION
This routine examines the structure of e to see if its complexity
(roughly the number of nodes) is greater than count. As soon as the
complexity exceeds this value it stops. It returns the difference
between count and the calculated complexity.
*/
static int complexity
(exp e, int count, int newdecs)
{
unsigned char n = name(e);
last_new_decs = newdecs;
if (count < 0)
return(-1);
if (newdecs > crit_decs)
return(-2);
if (son(e) == nilexp)
return(count);
switch (n) {
case apply_tag: {
if (newdecs > crit_decsatapp)
return(-3);
return(sbl(son(e), (count - apply_cost),
(newdecs + 1)));
}
case rep_tag: {
return(complexity(bro(son(e)), (count - 1),
(newdecs + 1)
));
}
case res_tag: {
return(complexity(son(e), (count + 1),
newdecs));
}
case ident_tag: {
return(sbl(son(e), (count - 1),
(newdecs + 1)));
}
case top_tag:
case clear_tag:
case val_tag: {
return(count);
}
case case_tag: {
return(complexity(son(e), (count - 1),
newdecs));
}
case name_tag:
case string_tag:
case env_offset_tag: {
return(count - 1);
}
case labst_tag: {
return(complexity(bro(son(e)), count, newdecs));
}
case solve_tag:
case seq_tag:
case cond_tag: {
return(sbl(son(e), count, newdecs));
}
default : {
return(sbl(son(e), (count - 1), newdecs));
}
}
/* NOT REACHED */
}
/* delivers 0 if no uses of this proc can be inlined.
delivers 1 if this use cannot be inlined
delivers 2 if this use can be inlined.
*/
int inlinechoice
(exp t, exp def, int total_uses)
{
int res;
exp apars;
exp fpars;
int newdecs = 0;
int no_actuals;
int max_complexity;
int nparam;
CONST int CONST_BONUS_UNIT = 16;
int const_param_bonus;
int adjusted_max_complexity;
shape shdef = pt(def) /* Oh, yes it is! */;
if (!eq_shape(sh(father(t)), shdef)) {
/* shape required by application is different from definition */
return 1;
}
nparam = 0;
const_param_bonus = 0;
max_complexity = (crit_inline / total_uses);
#if issparc
{
#define QQQ 2
int i;
if (total_uses >= (1<<QQQ))
{
for (i= total_uses >> QQQ; i>0; i >>=1)
{
max_complexity *= 3;
max_complexity /= 2;
}
}
#undef QQQ
}
#endif
if (max_complexity < 15) {
max_complexity = 15;
} else if (max_complexity > 120) {
max_complexity = 120;
}
apars = bro(t); /* only uses are applications */
no_actuals = last(t); /* if so then apars is apply_tag... */
fpars = son(def);
for (;;) {
if (name(fpars)!=ident_tag || !isparam(fpars)) {
/* first beyond formals */
if (!no_actuals)
newdecs = 10;
/* more actuals than formals, since last(apars)->break */
break;
}
nparam++;
switch (name(apars)) {
case val_tag: case real_tag: case string_tag: case name_tag:
break;
case cont_tag: {
if (name(son(apars)) ==name_tag && isvar(son(son(apars))) &&
!isvar(fpars))break;
} /* ... else continue */
default: newdecs++;
}
switch (name(apars))
{
case val_tag: {
int n = no(apars);
if (isbigval(apars))break;
/* Simple constant param. Increase desire to
inline since a constant may cause further
optimisation, eg strength reduction (mul
to shift) or dead code savings */
#define IS_POW2(c) ((c)!= 0 && ((c) & ((c) - 1)) == 0)
if (0) {
/* needs a register - poor */
const_param_bonus += CONST_BONUS_UNIT / 4;
} else if (n == 0 || (n > 0 && IS_POW2(n))) {
/* very good */
const_param_bonus += CONST_BONUS_UNIT;
} else {
/* less good */
const_param_bonus += CONST_BONUS_UNIT / 2;
}
break;
}
#undef IS_POW2
case real_tag:
/* reals not that useful */
const_param_bonus += CONST_BONUS_UNIT / 4;
break;
case string_tag:
case name_tag:
break;
case cont_tag:
if (name(son(apars)) == name_tag &&
isvar(son(son(apars))) &&
!isvar(fpars)) {
break;
}
/* FALL THROUGH */
default : {
newdecs++;
break;
}
}
fpars = bro(son(fpars));
if (last(apars))break;
apars = bro(apars);
}
adjusted_max_complexity = max_complexity;
/* increase to up to 3 times (average around 2) according
to const params */
if (nparam != 0) {
adjusted_max_complexity +=
(2 * max_complexity * const_param_bonus) /
(CONST_BONUS_UNIT * nparam);
}
/* increase by number of instructions saved for call */
adjusted_max_complexity += nparam - newdecs + 1;
if ((complexity(fpars, adjusted_max_complexity, newdecs)) >= 0)
res = 2;
else if (newdecs == 0)
res = 0;
else
res = 1;
return res;
}