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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.
*/
/*
$Log: weights.c,v $
* Revision 1.1.1.1 1998/01/17 15:56:03 release
* First version to be checked into rolling release.
*
* Revision 1.2 1995/12/18 13:12:46 wfs
* Put hppatrans uder cvs control. Major Changes made since last release
* include:
* (i) PIC code generation.
* (ii) Profiling.
* (iii) Dynamic Initialization.
* (iv) Debugging of Exception Handling and Diagnostics.
*
* Revision 5.0 1995/08/25 13:42:58 wfs
* Preperation for August 25 Glue release
*
* Revision 3.4 1995/08/25 10:41:19 wfs
* A few refinements necessary for 3.1 and 4.0 compatability.
*
* Revision 3.4 1995/08/25 10:41:19 wfs
* A few refinements necessary for 3.1 and 4.0 compatability.
*
* Revision 3.1 95/04/10 16:28:41 16:28:41 wfs (William Simmonds)
* Apr95 tape version.
*
* Revision 3.0 95/03/30 11:19:16 11:19:16 wfs (William Simmonds)
* Mar95 tape version with CRCR95_178 bug fix.
*
* Revision 2.0 95/03/15 15:29:06 15:29:06 wfs (William Simmonds)
* spec 3.1 changes implemented, tests outstanding.
*
* Revision 1.1 95/01/11 13:19:42 13:19:42 wfs (William Simmonds)
* Initial revision
*
*/
#define HPPATRANS_CODE
/******************************************************************
weights.c
The main procedure here is weightsv which determines
the allocation of s regs. It considers which of those tags not already
allocated to a t reg by scan, are best put in an s register. The same
conditions as for t regs apply as to the suitability of the tags for registers.
Weights estimates the usage of each tag and hence the amount that would
be saved if it were held in an s reg. Thus it computes break points for
register allocation for later use by reg_alloc.
The type weights consists of two arrays of integers. In the first
array each integer corresponds to a fixpnt reg and the second arrays'
integers correspond to floating point regs.
At the end of a call of weights on an ident exp the props field
of the ident may still contain inreg_bits or infreg_bits, set by scan, to
indicate that a t reg should be used. Otherwise number of ident is set up to
represent the break point for allocation. A similar process occurs for
proc parameters which have the break value in the forweights field
of the parapair of the corresponding procrec. This value has three
meanings:
1) The ident (or parameter) defines a fixpnt value and number
of ident (forweights of parpair) is an integer brk with the interpretation
that if there are at least brk fixpt s registers unallocated at this point then
one will be used for this tag (parameter).
2) As 1 but for floating point values.
3) number of ident = 100 in which case allocate value on the
stack, (this is obviously always available for parameters).
******************************************************************/
#include "config.h"
#include "exptypes.h"
#include "expmacs.h"
#include "codetypes.h"
#include "installtypes.h"
#include "const.h"
#include "exp.h"
#include "tags.h"
#include "common_types.h"
#include "proctypes.h"
#include "procrec.h"
#include "bitsmacs.h"
#include "maxminmacs.h"
#include "regable.h"
#include "comment.h"
#include "shapemacs.h"
#include "special.h"
#include "weights.h"
weights zeroweights =
{{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
},
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
}
};
/* NB scale, throughout, should be a float but mips cc V2.10 compiles calls and
proc body inconsistently !! */
weights weightsv(double, exp);
weights add_weights
(weights * w1, weights * w2)
{
/* sum of weights */
weights r;
long i;
for (i = 0; i < wfixno; ++i)
{
(r.fix)[i] = (w1->fix)[i] + (w2->fix)[i];
};
for (i = 0; i < wfloatno; ++i)
{
(r.floating)[i] = (w1->floating)[i] + (w2->floating)[i];
};
return(r);
}
wp max_weights
(double loc, weights * ws, bool fix)
{
/*
* loc is the usage count of a tag, ws is the weights computed for the scope
* of the tag and fix distinguishes between fix and float. This computes the
* weights for the declaration and a break point for register allocation
* which gives the number of available regs for which it is worthwhile to
* allocate this tag into a reg ("regged"). This proc is the source of all
* non-zero weights. NB loc may be negative since using a s-reg will involve
* a dump and restore
*/
long bk = wfixno + 1;
long i;
float *w = (ws->fix);
/* w[i] = greatest usage of (i+1) inner fixed tags */
wp res;
float *pw = & (((res.wp_weights).fix)[0]);
if (fix)
{
for (i = 0; i < wfixno; ++i)
{
if (i == 0)
{
if (loc > w[i])
{
/* this tag has higher usage than any inner one ... */
pw[i] = loc;
bk = i; /* ... so it's regged in pref to others */
}
else
pw[i] = w[i];
}
else
{
if ((loc + w[i - 1]) > w[i])
{
/*
* this tag and i inner ones have higher usage than any other (i+1)
* inner ones ...
*/
pw[i] = loc + w[i - 1];
if (i < bk)
bk = i;
/*
* ... so it and i inner ones are regged in preference to any other
* (i+1) inner ones
*/
}
else
pw[i] = w[i];
};
};
res.fix_break = bk;
}
else
{
for (i = 0; i < wfixno; ++i)
{
pw[i] = w[i];
}
}
#if NO_SREG
res.fix_break = wfixno + 1;
#else
res.fix_break = bk;
#endif
bk = wfloatno + 1;
w = (ws->floating);
pw = & (((res.wp_weights).floating)[0]);
if (!fix)
{ /* same algorithm for float regs as fixed regs */
for (i = 0; i < wfloatno; ++i)
{
if (i == 0)
{
if (loc > w[i])
{
pw[i] = loc;
bk = i;
}
else
pw[i] = w[i];
}
else
{
if ((loc + w[i - 1]) > w[i])
{
pw[i] = loc + w[i - 1];
if (i < bk)
bk = i;
}
else
pw[i] = w[i];
};
};
}
else
{
for (i = 0; i < wfloatno; ++i)
{
pw[i] = w[i];
}
}
res.float_break = bk;
return res;
}
weights mult_weights
(double m, weights * ws)
{
/*
* multiply weights by scalar - non overflowing
*/
weights res;
float *r = & (res.fix)[0];
float *w = ws->fix;
long i;
for (i = 0; i < wfixno; ++i)
{
r[i] = w[i]* m;
};
r = & (res.floating)[0];
w = ws->floating;
for (i = 0; i < wfloatno; ++i)
{
r[i] = w[i]* m;
};
return(res);
}
weights add_wlist
(double scale, exp re)
{ /* sum of weights of list re */
weights w, w1;
exp r = re;
if (r == nilexp)
{
return zeroweights;
}
else if (last(r))
{
return(weightsv(scale, r));
}
else
{
w = weightsv(scale, r);
do
{
r = bro(r);
w1 = weightsv(scale, r);
w = add_weights(&w, &w1);
} while (!last(r));
return w;
}
}
/*****************************************************************
weightsv
This procedure estimates the usage of tags and parameters to help
determine whether they can advantageously be placed in s registers.
The parameter scale allows more importance to be placed on usage
inside 'for' loops for example. The procedure reg_alloc in reg_alloc.c
finally determines the actual choice of s reg and recodes the number
field of an ident.
******************************************************************/
weights weightsv
(double scale, exp e)
{
unsigned char n;
tailrecurse:
n = name(e);
switch (n)
{
case name_tag:
{
exp s = son(e);
if (name(s) == ident_tag && !isglob(s))
{
if (is_floating(name(sh(e))) && name(sh(e))!= shrealhd)
{
fno(s) += scale * 2.0;
}
else
fno(s) += scale;
}
/* usage of tag stored in number of son of load_name (decl) */
return zeroweights;
};
case ident_tag:
{
if (son(e)!= nilexp)
{
weights wdef;
bool wdef_set;
weights wbody;
long noe = no(e) /* set by scan */ ;
#if 1
if (isparam(e))
{
/* initialising is a use */
fno(e) = scale;
wdef_set = 0;
}
else
#endif
if (name(son(e)) == clear_tag || props(e) & defer_bit)
{
wdef = zeroweights;
fno(e) = 0.0;
wdef_set = 0;
}
else
{
/* maybe needs a store to initialise */
if (is_floating(name(sh(son(e)))) && name(sh(son(e)))!= shrealhd)
{
fno(e) = scale * 2.0;
}
else
fno(e) = scale;
wdef = weightsv(scale, son(e));
wdef_set = 1;
}
/* weights for initialisation of dec */
wbody = weightsv(scale, bro(son(e)));
/* weights of body of scan */
if (props(e) & defer_bit)
{ /* declaration will be treated transparently
* in code production */
exp t = son(e);
exp s;
if ((name(t) == val_tag) || (name(t) == real_tag)) /* +++ string_tag too */
{
return wbody;
}
while (name(t)!= name_tag)
{
t = son(t);
}
s = son(t);
if (name(s) == ident_tag && !isglob(t))
{
fno(s) += fno(e);
}
/* usage of tag stored in number of son of load_name (decl) */
return wbody;
} /* end deferred */
if ((props(e) & inreg_bits) == 0 && fixregable(e))
{
wp p;
p = max_weights(fno(e) - 2.0 * scale, &wbody, 1);
no(e) = p.fix_break;
if (wdef_set)
return add_weights(&wdef, &p.wp_weights);
else
return p.wp_weights;
}
else if ((props(e) & infreg_bits) == 0 && floatregable(e))
{
wp p;
p = max_weights(fno(e) - 3.0 * scale, &wbody, 0);
/*
* usage decreased by 3 because of dump and restore of double s-reg
*/
no(e) = p.float_break /* was noe */ ;
if (wdef_set)
return add_weights(&wdef, &p.wp_weights);
else
return p.wp_weights;
}
else
{
no(e) = noe;
if (wdef_set)
return add_weights(&wdef, &wbody);
else
return wbody;
}
}
else
return zeroweights;
};
case rep_tag:
{
e = bro(son(e));
goto tailrecurse;
}
case case_tag:
{
e = son(e);
goto tailrecurse;
};
case labst_tag:
{
scale = fno(e)* scale;
e = bro(son(e));
goto tailrecurse;
}
case val_tag:
{
return zeroweights;
};
case ncopies_tag:
{
scale = no(e)* scale;
e = son(e);
goto tailrecurse;
}
default:
{
if (son(e) == nilexp || n == env_offset_tag
|| n == general_env_offset_tag)
{
return zeroweights;
}
if (last(son(e)))
{
e = son(e);
goto tailrecurse;
}
return(add_wlist(scale, son(e)));
}
}
}