800 lines
22 KiB
C
800 lines
22 KiB
C
/* Generic partial redundancy elimination with lazy code motion
|
|
support.
|
|
Copyright (C) 1998 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU CC.
|
|
|
|
GNU CC 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, or (at your option)
|
|
any later version.
|
|
|
|
GNU CC 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 GNU CC; see the file COPYING. If not, write to
|
|
the Free Software Foundation, 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
/* These routines are meant to be used by various optimization
|
|
passes which can be modeled as lazy code motion problems.
|
|
Including, but not limited to:
|
|
|
|
* Traditional partial redundancy elimination.
|
|
|
|
* Placement of caller/caller register save/restores.
|
|
|
|
* Load/store motion.
|
|
|
|
* Copy motion.
|
|
|
|
* Conversion of flat register files to a stacked register
|
|
model.
|
|
|
|
* Dead load/store elimination.
|
|
|
|
These routines accept as input:
|
|
|
|
* Basic block information (number of blocks, lists of
|
|
predecessors and successors). Note the granularity
|
|
does not need to be basic block, they could be statements
|
|
or functions.
|
|
|
|
* Bitmaps of local properties (computed, transparent and
|
|
anticipatable expressions).
|
|
|
|
The output of these routines is bitmap of redundant computations
|
|
and a bitmap of optimal placement points. */
|
|
|
|
|
|
#include "config.h"
|
|
#include "system.h"
|
|
|
|
#include "rtl.h"
|
|
#include "regs.h"
|
|
#include "hard-reg-set.h"
|
|
#include "flags.h"
|
|
#include "real.h"
|
|
#include "insn-config.h"
|
|
#include "recog.h"
|
|
#include "basic-block.h"
|
|
|
|
static void compute_antinout PROTO ((int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *, sbitmap *));
|
|
static void compute_earlyinout PROTO ((int, int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *, sbitmap *));
|
|
static void compute_delayinout PROTO ((int, int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *,
|
|
sbitmap *, sbitmap *));
|
|
static void compute_latein PROTO ((int, int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *));
|
|
static void compute_isoinout PROTO ((int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *, sbitmap *));
|
|
static void compute_optimal PROTO ((int, sbitmap *,
|
|
sbitmap *, sbitmap *));
|
|
static void compute_redundant PROTO ((int, int, sbitmap *,
|
|
sbitmap *, sbitmap *, sbitmap *));
|
|
|
|
/* Similarly, but for the reversed flowgraph. */
|
|
static void compute_avinout PROTO ((int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *, sbitmap *));
|
|
static void compute_fartherinout PROTO ((int, int, int_list_ptr *,
|
|
sbitmap *, sbitmap *,
|
|
sbitmap *, sbitmap *));
|
|
static void compute_earlierinout PROTO ((int, int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *,
|
|
sbitmap *, sbitmap *));
|
|
static void compute_firstout PROTO ((int, int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *));
|
|
static void compute_rev_isoinout PROTO ((int, int_list_ptr *, sbitmap *,
|
|
sbitmap *, sbitmap *, sbitmap *));
|
|
|
|
/* Given local properties TRANSP, ANTLOC, return the redundant and optimal
|
|
computation points for expressions.
|
|
|
|
To reduce overall memory consumption, we allocate memory immediately
|
|
before its needed and deallocate it as soon as possible. */
|
|
void
|
|
pre_lcm (n_blocks, n_exprs, s_preds, s_succs, transp,
|
|
antloc, redundant, optimal)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_preds;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *transp;
|
|
sbitmap *antloc;
|
|
sbitmap *redundant;
|
|
sbitmap *optimal;
|
|
{
|
|
sbitmap *antin, *antout, *earlyin, *earlyout, *delayin, *delayout;
|
|
sbitmap *latein, *isoin, *isoout;
|
|
|
|
/* Compute global anticipatability. ANTOUT is not needed except to
|
|
compute ANTIN, so free its memory as soon as we return from
|
|
compute_antinout. */
|
|
antin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
antout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_antinout (n_blocks, s_succs, antloc,
|
|
transp, antin, antout);
|
|
free (antout);
|
|
antout = NULL;
|
|
|
|
/* Compute earliestness. EARLYOUT is not needed except to compute
|
|
EARLYIN, so free its memory as soon as we return from
|
|
compute_earlyinout. */
|
|
earlyin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
earlyout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_earlyinout (n_blocks, n_exprs, s_preds, transp, antin,
|
|
earlyin, earlyout);
|
|
free (earlyout);
|
|
earlyout = NULL;
|
|
|
|
/* Compute delayedness. DELAYOUT is not needed except to compute
|
|
DELAYIN, so free its memory as soon as we return from
|
|
compute_delayinout. We also no longer need ANTIN and EARLYIN. */
|
|
delayin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
delayout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_delayinout (n_blocks, n_exprs, s_preds, antloc,
|
|
antin, earlyin, delayin, delayout);
|
|
free (delayout);
|
|
delayout = NULL;
|
|
free (antin);
|
|
antin = NULL;
|
|
free (earlyin);
|
|
earlyin = NULL;
|
|
|
|
/* Compute latestness. We no longer need DELAYIN after we compute
|
|
LATEIN. */
|
|
latein = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_latein (n_blocks, n_exprs, s_succs, antloc, delayin, latein);
|
|
free (delayin);
|
|
delayin = NULL;
|
|
|
|
/* Compute isolatedness. ISOIN is not needed except to compute
|
|
ISOOUT, so free its memory as soon as we return from
|
|
compute_isoinout. */
|
|
isoin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
isoout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_isoinout (n_blocks, s_succs, antloc, latein, isoin, isoout);
|
|
free (isoin);
|
|
isoin = NULL;
|
|
|
|
/* Now compute optimal placement points and the redundant expressions. */
|
|
compute_optimal (n_blocks, latein, isoout, optimal);
|
|
compute_redundant (n_blocks, n_exprs, antloc, latein, isoout, redundant);
|
|
free (latein);
|
|
latein = NULL;
|
|
free (isoout);
|
|
isoout = NULL;
|
|
}
|
|
|
|
/* Given local properties TRANSP, AVLOC, return the redundant and optimal
|
|
computation points for expressions on the reverse flowgraph.
|
|
|
|
To reduce overall memory consumption, we allocate memory immediately
|
|
before its needed and deallocate it as soon as possible. */
|
|
|
|
void
|
|
pre_rev_lcm (n_blocks, n_exprs, s_preds, s_succs, transp,
|
|
avloc, redundant, optimal)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_preds;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *transp;
|
|
sbitmap *avloc;
|
|
sbitmap *redundant;
|
|
sbitmap *optimal;
|
|
{
|
|
sbitmap *avin, *avout, *fartherin, *fartherout, *earlierin, *earlierout;
|
|
sbitmap *firstout, *rev_isoin, *rev_isoout;
|
|
|
|
/* Compute global availability. AVIN is not needed except to
|
|
compute AVOUT, so free its memory as soon as we return from
|
|
compute_avinout. */
|
|
avin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
avout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_avinout (n_blocks, s_preds, avloc, transp, avin, avout);
|
|
free (avin);
|
|
avin = NULL;
|
|
|
|
/* Compute fartherness. FARTHERIN is not needed except to compute
|
|
FARTHEROUT, so free its memory as soon as we return from
|
|
compute_earlyinout. */
|
|
fartherin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
fartherout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_fartherinout (n_blocks, n_exprs, s_succs, transp,
|
|
avout, fartherin, fartherout);
|
|
free (fartherin);
|
|
fartherin = NULL;
|
|
|
|
/* Compute earlierness. EARLIERIN is not needed except to compute
|
|
EARLIEROUT, so free its memory as soon as we return from
|
|
compute_delayinout. We also no longer need AVOUT and FARTHEROUT. */
|
|
earlierin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
earlierout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_earlierinout (n_blocks, n_exprs, s_succs, avloc,
|
|
avout, fartherout, earlierin, earlierout);
|
|
free (earlierin);
|
|
earlierin = NULL;
|
|
free (avout);
|
|
avout = NULL;
|
|
free (fartherout);
|
|
fartherout = NULL;
|
|
|
|
/* Compute firstness. We no longer need EARLIEROUT after we compute
|
|
FIRSTOUT. */
|
|
firstout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_firstout (n_blocks, n_exprs, s_preds, avloc, earlierout, firstout);
|
|
free (earlierout);
|
|
earlierout = NULL;
|
|
|
|
/* Compute rev_isolatedness. ISOIN is not needed except to compute
|
|
ISOOUT, so free its memory as soon as we return from
|
|
compute_isoinout. */
|
|
rev_isoin = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
rev_isoout = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
compute_rev_isoinout (n_blocks, s_preds, avloc, firstout,
|
|
rev_isoin, rev_isoout);
|
|
free (rev_isoout);
|
|
rev_isoout = NULL;
|
|
|
|
/* Now compute optimal placement points and the redundant expressions. */
|
|
compute_optimal (n_blocks, firstout, rev_isoin, optimal);
|
|
compute_redundant (n_blocks, n_exprs, avloc, firstout, rev_isoin, redundant);
|
|
free (firstout);
|
|
firstout = NULL;
|
|
free (rev_isoin);
|
|
rev_isoin = NULL;
|
|
}
|
|
|
|
/* Compute expression anticipatability at entrance and exit of each block. */
|
|
|
|
static void
|
|
compute_antinout (n_blocks, s_succs, antloc, transp, antin, antout)
|
|
int n_blocks;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *antloc;
|
|
sbitmap *transp;
|
|
sbitmap *antin;
|
|
sbitmap *antout;
|
|
{
|
|
int bb, changed, passes;
|
|
sbitmap old_changed, new_changed;
|
|
|
|
sbitmap_zero (antout[n_blocks - 1]);
|
|
sbitmap_vector_ones (antin, n_blocks);
|
|
|
|
old_changed = sbitmap_alloc (n_blocks);
|
|
new_changed = sbitmap_alloc (n_blocks);
|
|
sbitmap_ones (old_changed);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
sbitmap_zero (new_changed);
|
|
/* We scan the blocks in the reverse order to speed up
|
|
the convergence. */
|
|
for (bb = n_blocks - 1; bb >= 0; bb--)
|
|
{
|
|
int_list_ptr ps;
|
|
|
|
/* If none of the successors of this block have changed,
|
|
then this block is not going to change. */
|
|
for (ps = s_succs[bb] ; ps; ps = ps->next)
|
|
{
|
|
if (INT_LIST_VAL (ps) == EXIT_BLOCK
|
|
|| INT_LIST_VAL (ps) == ENTRY_BLOCK)
|
|
break;
|
|
|
|
if (TEST_BIT (old_changed, INT_LIST_VAL (ps))
|
|
|| TEST_BIT (new_changed, INT_LIST_VAL (ps)))
|
|
break;
|
|
}
|
|
|
|
if (!ps)
|
|
continue;
|
|
|
|
if (bb != n_blocks - 1)
|
|
sbitmap_intersect_of_successors (antout[bb], antin,
|
|
bb, s_succs);
|
|
if (sbitmap_a_or_b_and_c (antin[bb], antloc[bb],
|
|
transp[bb], antout[bb]))
|
|
{
|
|
changed = 1;
|
|
SET_BIT (new_changed, bb);
|
|
}
|
|
}
|
|
sbitmap_copy (old_changed, new_changed);
|
|
passes++;
|
|
}
|
|
free (old_changed);
|
|
free (new_changed);
|
|
}
|
|
|
|
/* Compute expression earliestness at entrance and exit of each block.
|
|
|
|
From Advanced Compiler Design and Implementation pp411.
|
|
|
|
An expression is earliest at the entrance to basic block BB if no
|
|
block from entry to block BB both evaluates the expression and
|
|
produces the same value as evaluating it at the entry to block BB
|
|
does. Similarly for earlistness at basic block BB exit. */
|
|
|
|
static void
|
|
compute_earlyinout (n_blocks, n_exprs, s_preds, transp, antin,
|
|
earlyin, earlyout)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_preds;
|
|
sbitmap *transp;
|
|
sbitmap *antin;
|
|
sbitmap *earlyin;
|
|
sbitmap *earlyout;
|
|
{
|
|
int bb, changed, passes;
|
|
sbitmap temp_bitmap;
|
|
sbitmap old_changed, new_changed;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
sbitmap_vector_zero (earlyout, n_blocks);
|
|
sbitmap_ones (earlyin[0]);
|
|
|
|
old_changed = sbitmap_alloc (n_blocks);
|
|
new_changed = sbitmap_alloc (n_blocks);
|
|
sbitmap_ones (old_changed);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
sbitmap_zero (new_changed);
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
int_list_ptr ps;
|
|
|
|
/* If none of the predecessors of this block have changed,
|
|
then this block is not going to change. */
|
|
for (ps = s_preds[bb] ; ps; ps = ps->next)
|
|
{
|
|
if (INT_LIST_VAL (ps) == EXIT_BLOCK
|
|
|| INT_LIST_VAL (ps) == ENTRY_BLOCK)
|
|
break;
|
|
|
|
if (TEST_BIT (old_changed, INT_LIST_VAL (ps))
|
|
|| TEST_BIT (new_changed, INT_LIST_VAL (ps)))
|
|
break;
|
|
}
|
|
|
|
if (!ps)
|
|
continue;
|
|
|
|
if (bb != 0)
|
|
sbitmap_union_of_predecessors (earlyin[bb], earlyout,
|
|
bb, s_preds);
|
|
sbitmap_not (temp_bitmap, transp[bb]);
|
|
if (sbitmap_union_of_diff (earlyout[bb], temp_bitmap,
|
|
earlyin[bb], antin[bb]))
|
|
{
|
|
changed = 1;
|
|
SET_BIT (new_changed, bb);
|
|
}
|
|
}
|
|
sbitmap_copy (old_changed, new_changed);
|
|
passes++;
|
|
}
|
|
free (old_changed);
|
|
free (new_changed);
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute expression delayedness at entrance and exit of each block.
|
|
|
|
From Advanced Compiler Design and Implementation pp411.
|
|
|
|
An expression is delayed at the entrance to BB if it is anticipatable
|
|
and earliest at that point and if all subsequent computations of
|
|
the expression are in block BB. */
|
|
|
|
static void
|
|
compute_delayinout (n_blocks, n_exprs, s_preds, antloc,
|
|
antin, earlyin, delayin, delayout)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_preds;
|
|
sbitmap *antloc;
|
|
sbitmap *antin;
|
|
sbitmap *earlyin;
|
|
sbitmap *delayin;
|
|
sbitmap *delayout;
|
|
{
|
|
int bb, changed, passes;
|
|
sbitmap *anti_and_early;
|
|
sbitmap temp_bitmap;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
/* This is constant throughout the flow equations below, so compute
|
|
it once to save time. */
|
|
anti_and_early = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
sbitmap_a_and_b (anti_and_early[bb], antin[bb], earlyin[bb]);
|
|
|
|
sbitmap_vector_zero (delayout, n_blocks);
|
|
sbitmap_copy (delayin[0], anti_and_early[0]);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
if (bb != 0)
|
|
{
|
|
sbitmap_intersect_of_predecessors (temp_bitmap, delayout,
|
|
bb, s_preds);
|
|
changed |= sbitmap_a_or_b (delayin[bb],
|
|
anti_and_early[bb],
|
|
temp_bitmap);
|
|
}
|
|
sbitmap_not (temp_bitmap, antloc[bb]);
|
|
changed |= sbitmap_a_and_b (delayout[bb],
|
|
temp_bitmap,
|
|
delayin[bb]);
|
|
}
|
|
passes++;
|
|
}
|
|
|
|
/* We're done with this, so go ahead and free it's memory now instead
|
|
of waiting until the end of pre. */
|
|
free (anti_and_early);
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute latestness.
|
|
|
|
From Advanced Compiler Design and Implementation pp412.
|
|
|
|
An expression is latest at the entrance to block BB if that is an optimal
|
|
point for computing the expression and if on every path from block BB's
|
|
entrance to the exit block, any optimal computation point for the
|
|
expression occurs after one of the points at which the expression was
|
|
computed in the original flowgraph. */
|
|
|
|
static void
|
|
compute_latein (n_blocks, n_exprs, s_succs, antloc, delayin, latein)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *antloc;
|
|
sbitmap *delayin;
|
|
sbitmap *latein;
|
|
{
|
|
int bb;
|
|
sbitmap temp_bitmap;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
/* The last block is succeeded only by the exit block; therefore,
|
|
temp_bitmap will not be set by the following call! */
|
|
if (bb == n_blocks - 1)
|
|
{
|
|
sbitmap_intersect_of_successors (temp_bitmap, delayin,
|
|
bb, s_succs);
|
|
sbitmap_not (temp_bitmap, temp_bitmap);
|
|
}
|
|
else
|
|
sbitmap_ones (temp_bitmap);
|
|
sbitmap_a_and_b_or_c (latein[bb], delayin[bb],
|
|
antloc[bb], temp_bitmap);
|
|
}
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute isolated.
|
|
|
|
From Advanced Compiler Design and Implementation pp413.
|
|
|
|
A computationally optimal placement for the evaluation of an expression
|
|
is defined to be isolated if and only if on every path from a successor
|
|
of the block in which it is computed to the exit block, every original
|
|
computation of the expression is preceded by the optimal placement point. */
|
|
|
|
static void
|
|
compute_isoinout (n_blocks, s_succs, antloc, latein, isoin, isoout)
|
|
int n_blocks;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *antloc;
|
|
sbitmap *latein;
|
|
sbitmap *isoin;
|
|
sbitmap *isoout;
|
|
{
|
|
int bb, changed, passes;
|
|
|
|
sbitmap_vector_zero (isoin, n_blocks);
|
|
sbitmap_zero (isoout[n_blocks - 1]);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
for (bb = n_blocks - 1; bb >= 0; bb--)
|
|
{
|
|
if (bb != n_blocks - 1)
|
|
sbitmap_intersect_of_successors (isoout[bb], isoin,
|
|
bb, s_succs);
|
|
changed |= sbitmap_union_of_diff (isoin[bb], latein[bb],
|
|
isoout[bb], antloc[bb]);
|
|
}
|
|
passes++;
|
|
}
|
|
}
|
|
|
|
/* Compute the set of expressions which have optimal computational points
|
|
in each basic block. This is the set of expressions that are latest, but
|
|
that are not isolated in the block. */
|
|
|
|
static void
|
|
compute_optimal (n_blocks, latein, isoout, optimal)
|
|
int n_blocks;
|
|
sbitmap *latein;
|
|
sbitmap *isoout;
|
|
sbitmap *optimal;
|
|
{
|
|
int bb;
|
|
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
sbitmap_difference (optimal[bb], latein[bb], isoout[bb]);
|
|
}
|
|
|
|
/* Compute the set of expressions that are redundant in a block. They are
|
|
the expressions that are used in the block and that are neither isolated
|
|
or latest. */
|
|
|
|
static void
|
|
compute_redundant (n_blocks, n_exprs, antloc, latein, isoout, redundant)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
sbitmap *antloc;
|
|
sbitmap *latein;
|
|
sbitmap *isoout;
|
|
sbitmap *redundant;
|
|
{
|
|
int bb;
|
|
sbitmap temp_bitmap;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
sbitmap_a_or_b (temp_bitmap, latein[bb], isoout[bb]);
|
|
sbitmap_difference (redundant[bb], antloc[bb], temp_bitmap);
|
|
}
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute expression availability at entrance and exit of each block. */
|
|
|
|
static void
|
|
compute_avinout (n_blocks, s_preds, avloc, transp, avin, avout)
|
|
int n_blocks;
|
|
int_list_ptr *s_preds;
|
|
sbitmap *avloc;
|
|
sbitmap *transp;
|
|
sbitmap *avin;
|
|
sbitmap *avout;
|
|
{
|
|
int bb, changed, passes;
|
|
|
|
sbitmap_zero (avin[0]);
|
|
sbitmap_vector_ones (avout, n_blocks);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
if (bb != 0)
|
|
sbitmap_intersect_of_predecessors (avin[bb], avout,
|
|
bb, s_preds);
|
|
changed |= sbitmap_a_or_b_and_c (avout[bb], avloc[bb],
|
|
transp[bb], avin[bb]);
|
|
}
|
|
passes++;
|
|
}
|
|
}
|
|
|
|
/* Compute expression latestness.
|
|
|
|
This is effectively the same as earliestness computed on the reverse
|
|
flow graph. */
|
|
|
|
static void
|
|
compute_fartherinout (n_blocks, n_exprs, s_succs,
|
|
transp, avout, fartherin, fartherout)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *transp;
|
|
sbitmap *avout;
|
|
sbitmap *fartherin;
|
|
sbitmap *fartherout;
|
|
{
|
|
int bb, changed, passes;
|
|
sbitmap temp_bitmap;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
sbitmap_vector_zero (fartherin, n_blocks);
|
|
sbitmap_ones (fartherout[n_blocks - 1]);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
for (bb = n_blocks - 1; bb >= 0; bb--)
|
|
{
|
|
if (bb != n_blocks - 1)
|
|
sbitmap_union_of_successors (fartherout[bb], fartherin,
|
|
bb, s_succs);
|
|
sbitmap_not (temp_bitmap, transp[bb]);
|
|
changed |= sbitmap_union_of_diff (fartherin[bb], temp_bitmap,
|
|
fartherout[bb], avout[bb]);
|
|
}
|
|
passes++;
|
|
}
|
|
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute expression earlierness at entrance and exit of each block.
|
|
|
|
This is effectively the same as delayedness computed on the reverse
|
|
flow graph. */
|
|
|
|
static void
|
|
compute_earlierinout (n_blocks, n_exprs, s_succs, avloc,
|
|
avout, fartherout, earlierin, earlierout)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_succs;
|
|
sbitmap *avloc;
|
|
sbitmap *avout;
|
|
sbitmap *fartherout;
|
|
sbitmap *earlierin;
|
|
sbitmap *earlierout;
|
|
{
|
|
int bb, changed, passes;
|
|
sbitmap *av_and_farther;
|
|
sbitmap temp_bitmap;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
/* This is constant throughout the flow equations below, so compute
|
|
it once to save time. */
|
|
av_and_farther = sbitmap_vector_alloc (n_blocks, n_exprs);
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
sbitmap_a_and_b (av_and_farther[bb], avout[bb], fartherout[bb]);
|
|
|
|
sbitmap_vector_zero (earlierin, n_blocks);
|
|
sbitmap_copy (earlierout[n_blocks - 1], av_and_farther[n_blocks - 1]);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
for (bb = n_blocks - 1; bb >= 0; bb--)
|
|
{
|
|
if (bb != n_blocks - 1)
|
|
{
|
|
sbitmap_intersect_of_successors (temp_bitmap, earlierin,
|
|
bb, s_succs);
|
|
changed |= sbitmap_a_or_b (earlierout[bb],
|
|
av_and_farther[bb],
|
|
temp_bitmap);
|
|
}
|
|
sbitmap_not (temp_bitmap, avloc[bb]);
|
|
changed |= sbitmap_a_and_b (earlierin[bb],
|
|
temp_bitmap,
|
|
earlierout[bb]);
|
|
}
|
|
passes++;
|
|
}
|
|
|
|
/* We're done with this, so go ahead and free it's memory now instead
|
|
of waiting until the end of pre. */
|
|
free (av_and_farther);
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute firstness.
|
|
|
|
This is effectively the same as latestness computed on the reverse
|
|
flow graph. */
|
|
|
|
static void
|
|
compute_firstout (n_blocks, n_exprs, s_preds, avloc, earlierout, firstout)
|
|
int n_blocks;
|
|
int n_exprs;
|
|
int_list_ptr *s_preds;
|
|
sbitmap *avloc;
|
|
sbitmap *earlierout;
|
|
sbitmap *firstout;
|
|
{
|
|
int bb;
|
|
sbitmap temp_bitmap;
|
|
|
|
temp_bitmap = sbitmap_alloc (n_exprs);
|
|
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
/* The first block is preceded only by the entry block; therefore,
|
|
temp_bitmap will not be set by the following call! */
|
|
if (bb != 0)
|
|
{
|
|
sbitmap_intersect_of_predecessors (temp_bitmap, earlierout,
|
|
bb, s_preds);
|
|
sbitmap_not (temp_bitmap, temp_bitmap);
|
|
}
|
|
else
|
|
{
|
|
sbitmap_ones (temp_bitmap);
|
|
}
|
|
sbitmap_a_and_b_or_c (firstout[bb], earlierout[bb],
|
|
avloc[bb], temp_bitmap);
|
|
}
|
|
free (temp_bitmap);
|
|
}
|
|
|
|
/* Compute reverse isolated.
|
|
|
|
This is effectively the same as isolatedness computed on the reverse
|
|
flow graph. */
|
|
|
|
static void
|
|
compute_rev_isoinout (n_blocks, s_preds, avloc, firstout,
|
|
rev_isoin, rev_isoout)
|
|
int n_blocks;
|
|
int_list_ptr *s_preds;
|
|
sbitmap *avloc;
|
|
sbitmap *firstout;
|
|
sbitmap *rev_isoin;
|
|
sbitmap *rev_isoout;
|
|
{
|
|
int bb, changed, passes;
|
|
|
|
sbitmap_vector_zero (rev_isoout, n_blocks);
|
|
sbitmap_zero (rev_isoin[0]);
|
|
|
|
passes = 0;
|
|
changed = 1;
|
|
while (changed)
|
|
{
|
|
changed = 0;
|
|
for (bb = 0; bb < n_blocks; bb++)
|
|
{
|
|
if (bb != 0)
|
|
sbitmap_intersect_of_predecessors (rev_isoin[bb], rev_isoout,
|
|
bb, s_preds);
|
|
changed |= sbitmap_union_of_diff (rev_isoout[bb], firstout[bb],
|
|
rev_isoin[bb], avloc[bb]);
|
|
}
|
|
passes++;
|
|
}
|
|
}
|