--- /dev/null
+/* 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++;
+ }
+}
projects / gcc.git / commitdiff