2006 lines
59 KiB
C
2006 lines
59 KiB
C
/* Instruction scheduling pass.
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Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998,
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1999, 2000, 2001, 2002 Free Software Foundation, Inc.
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Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by,
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and currently maintained by, Jim Wilson (wilson@cygnus.com)
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to the Free
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Software Foundation, 59 Temple Place - Suite 330, Boston, MA
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02111-1307, USA. */
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/* Instruction scheduling pass. This file, along with sched-deps.c,
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contains the generic parts. The actual entry point is found for
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the normal instruction scheduling pass is found in sched-rgn.c.
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We compute insn priorities based on data dependencies. Flow
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analysis only creates a fraction of the data-dependencies we must
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observe: namely, only those dependencies which the combiner can be
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expected to use. For this pass, we must therefore create the
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remaining dependencies we need to observe: register dependencies,
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memory dependencies, dependencies to keep function calls in order,
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and the dependence between a conditional branch and the setting of
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condition codes are all dealt with here.
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The scheduler first traverses the data flow graph, starting with
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the last instruction, and proceeding to the first, assigning values
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to insn_priority as it goes. This sorts the instructions
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topologically by data dependence.
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Once priorities have been established, we order the insns using
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list scheduling. This works as follows: starting with a list of
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all the ready insns, and sorted according to priority number, we
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schedule the insn from the end of the list by placing its
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predecessors in the list according to their priority order. We
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consider this insn scheduled by setting the pointer to the "end" of
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the list to point to the previous insn. When an insn has no
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predecessors, we either queue it until sufficient time has elapsed
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or add it to the ready list. As the instructions are scheduled or
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when stalls are introduced, the queue advances and dumps insns into
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the ready list. When all insns down to the lowest priority have
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been scheduled, the critical path of the basic block has been made
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as short as possible. The remaining insns are then scheduled in
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remaining slots.
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Function unit conflicts are resolved during forward list scheduling
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by tracking the time when each insn is committed to the schedule
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and from that, the time the function units it uses must be free.
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As insns on the ready list are considered for scheduling, those
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that would result in a blockage of the already committed insns are
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queued until no blockage will result.
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The following list shows the order in which we want to break ties
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among insns in the ready list:
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1. choose insn with the longest path to end of bb, ties
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broken by
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2. choose insn with least contribution to register pressure,
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ties broken by
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3. prefer in-block upon interblock motion, ties broken by
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4. prefer useful upon speculative motion, ties broken by
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5. choose insn with largest control flow probability, ties
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broken by
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6. choose insn with the least dependences upon the previously
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scheduled insn, or finally
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7 choose the insn which has the most insns dependent on it.
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8. choose insn with lowest UID.
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Memory references complicate matters. Only if we can be certain
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that memory references are not part of the data dependency graph
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(via true, anti, or output dependence), can we move operations past
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memory references. To first approximation, reads can be done
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independently, while writes introduce dependencies. Better
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approximations will yield fewer dependencies.
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Before reload, an extended analysis of interblock data dependences
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is required for interblock scheduling. This is performed in
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compute_block_backward_dependences ().
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Dependencies set up by memory references are treated in exactly the
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same way as other dependencies, by using LOG_LINKS backward
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dependences. LOG_LINKS are translated into INSN_DEPEND forward
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dependences for the purpose of forward list scheduling.
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Having optimized the critical path, we may have also unduly
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extended the lifetimes of some registers. If an operation requires
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that constants be loaded into registers, it is certainly desirable
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to load those constants as early as necessary, but no earlier.
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I.e., it will not do to load up a bunch of registers at the
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beginning of a basic block only to use them at the end, if they
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could be loaded later, since this may result in excessive register
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utilization.
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Note that since branches are never in basic blocks, but only end
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basic blocks, this pass will not move branches. But that is ok,
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since we can use GNU's delayed branch scheduling pass to take care
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of this case.
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Also note that no further optimizations based on algebraic
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identities are performed, so this pass would be a good one to
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perform instruction splitting, such as breaking up a multiply
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instruction into shifts and adds where that is profitable.
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Given the memory aliasing analysis that this pass should perform,
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it should be possible to remove redundant stores to memory, and to
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load values from registers instead of hitting memory.
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Before reload, speculative insns are moved only if a 'proof' exists
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that no exception will be caused by this, and if no live registers
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exist that inhibit the motion (live registers constraints are not
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represented by data dependence edges).
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This pass must update information that subsequent passes expect to
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be correct. Namely: reg_n_refs, reg_n_sets, reg_n_deaths,
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reg_n_calls_crossed, and reg_live_length. Also, BLOCK_HEAD,
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BLOCK_END.
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The information in the line number notes is carefully retained by
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this pass. Notes that refer to the starting and ending of
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exception regions are also carefully retained by this pass. All
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other NOTE insns are grouped in their same relative order at the
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beginning of basic blocks and regions that have been scheduled. */
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#include "config.h"
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#include "system.h"
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#include "toplev.h"
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#include "rtl.h"
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#include "tm_p.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "regs.h"
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#include "function.h"
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#include "flags.h"
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#include "insn-config.h"
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#include "insn-attr.h"
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#include "except.h"
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#include "toplev.h"
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#include "recog.h"
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#include "sched-int.h"
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#include "target.h"
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#ifdef INSN_SCHEDULING
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/* issue_rate is the number of insns that can be scheduled in the same
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machine cycle. It can be defined in the config/mach/mach.h file,
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otherwise we set it to 1. */
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static int issue_rate;
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/* sched-verbose controls the amount of debugging output the
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scheduler prints. It is controlled by -fsched-verbose=N:
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N>0 and no -DSR : the output is directed to stderr.
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N>=10 will direct the printouts to stderr (regardless of -dSR).
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N=1: same as -dSR.
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N=2: bb's probabilities, detailed ready list info, unit/insn info.
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N=3: rtl at abort point, control-flow, regions info.
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N=5: dependences info. */
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static int sched_verbose_param = 0;
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int sched_verbose = 0;
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/* Debugging file. All printouts are sent to dump, which is always set,
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either to stderr, or to the dump listing file (-dRS). */
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FILE *sched_dump = 0;
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/* Highest uid before scheduling. */
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static int old_max_uid;
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/* fix_sched_param() is called from toplev.c upon detection
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of the -fsched-verbose=N option. */
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void
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fix_sched_param (param, val)
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const char *param, *val;
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{
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if (!strcmp (param, "verbose"))
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sched_verbose_param = atoi (val);
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else
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warning ("fix_sched_param: unknown param: %s", param);
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}
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struct haifa_insn_data *h_i_d;
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#define DONE_PRIORITY -1
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#define MAX_PRIORITY 0x7fffffff
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#define TAIL_PRIORITY 0x7ffffffe
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#define LAUNCH_PRIORITY 0x7f000001
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#define DONE_PRIORITY_P(INSN) (INSN_PRIORITY (INSN) < 0)
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#define LOW_PRIORITY_P(INSN) ((INSN_PRIORITY (INSN) & 0x7f000000) == 0)
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#define LINE_NOTE(INSN) (h_i_d[INSN_UID (INSN)].line_note)
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#define INSN_TICK(INSN) (h_i_d[INSN_UID (INSN)].tick)
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/* Vector indexed by basic block number giving the starting line-number
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for each basic block. */
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static rtx *line_note_head;
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/* List of important notes we must keep around. This is a pointer to the
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last element in the list. */
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static rtx note_list;
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/* Queues, etc. */
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/* An instruction is ready to be scheduled when all insns preceding it
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have already been scheduled. It is important to ensure that all
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insns which use its result will not be executed until its result
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has been computed. An insn is maintained in one of four structures:
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(P) the "Pending" set of insns which cannot be scheduled until
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their dependencies have been satisfied.
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(Q) the "Queued" set of insns that can be scheduled when sufficient
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time has passed.
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(R) the "Ready" list of unscheduled, uncommitted insns.
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(S) the "Scheduled" list of insns.
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Initially, all insns are either "Pending" or "Ready" depending on
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whether their dependencies are satisfied.
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Insns move from the "Ready" list to the "Scheduled" list as they
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are committed to the schedule. As this occurs, the insns in the
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"Pending" list have their dependencies satisfied and move to either
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the "Ready" list or the "Queued" set depending on whether
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sufficient time has passed to make them ready. As time passes,
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insns move from the "Queued" set to the "Ready" list. Insns may
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move from the "Ready" list to the "Queued" set if they are blocked
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due to a function unit conflict.
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The "Pending" list (P) are the insns in the INSN_DEPEND of the unscheduled
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insns, i.e., those that are ready, queued, and pending.
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The "Queued" set (Q) is implemented by the variable `insn_queue'.
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The "Ready" list (R) is implemented by the variables `ready' and
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`n_ready'.
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The "Scheduled" list (S) is the new insn chain built by this pass.
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The transition (R->S) is implemented in the scheduling loop in
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`schedule_block' when the best insn to schedule is chosen.
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The transition (R->Q) is implemented in `queue_insn' when an
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insn is found to have a function unit conflict with the already
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committed insns.
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The transitions (P->R and P->Q) are implemented in `schedule_insn' as
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insns move from the ready list to the scheduled list.
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The transition (Q->R) is implemented in 'queue_to_insn' as time
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passes or stalls are introduced. */
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/* Implement a circular buffer to delay instructions until sufficient
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time has passed. INSN_QUEUE_SIZE is a power of two larger than
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MAX_BLOCKAGE and MAX_READY_COST computed by genattr.c. This is the
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longest time an isnsn may be queued. */
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static rtx insn_queue[INSN_QUEUE_SIZE];
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static int q_ptr = 0;
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static int q_size = 0;
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#define NEXT_Q(X) (((X)+1) & (INSN_QUEUE_SIZE-1))
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#define NEXT_Q_AFTER(X, C) (((X)+C) & (INSN_QUEUE_SIZE-1))
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/* Describe the ready list of the scheduler.
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VEC holds space enough for all insns in the current region. VECLEN
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says how many exactly.
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FIRST is the index of the element with the highest priority; i.e. the
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last one in the ready list, since elements are ordered by ascending
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priority.
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N_READY determines how many insns are on the ready list. */
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struct ready_list
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{
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rtx *vec;
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int veclen;
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int first;
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int n_ready;
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};
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/* Forward declarations. */
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static unsigned int blockage_range PARAMS ((int, rtx));
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static void clear_units PARAMS ((void));
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static void schedule_unit PARAMS ((int, rtx, int));
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static int actual_hazard PARAMS ((int, rtx, int, int));
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static int potential_hazard PARAMS ((int, rtx, int));
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static int priority PARAMS ((rtx));
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static int rank_for_schedule PARAMS ((const PTR, const PTR));
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static void swap_sort PARAMS ((rtx *, int));
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static void queue_insn PARAMS ((rtx, int));
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static void schedule_insn PARAMS ((rtx, struct ready_list *, int));
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static void find_insn_reg_weight PARAMS ((int));
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static void adjust_priority PARAMS ((rtx));
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/* Notes handling mechanism:
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=========================
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Generally, NOTES are saved before scheduling and restored after scheduling.
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The scheduler distinguishes between three types of notes:
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(1) LINE_NUMBER notes, generated and used for debugging. Here,
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before scheduling a region, a pointer to the LINE_NUMBER note is
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added to the insn following it (in save_line_notes()), and the note
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is removed (in rm_line_notes() and unlink_line_notes()). After
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scheduling the region, this pointer is used for regeneration of
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the LINE_NUMBER note (in restore_line_notes()).
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(2) LOOP_BEGIN, LOOP_END, SETJMP, EHREGION_BEG, EHREGION_END notes:
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Before scheduling a region, a pointer to the note is added to the insn
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that follows or precedes it. (This happens as part of the data dependence
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computation). After scheduling an insn, the pointer contained in it is
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used for regenerating the corresponding note (in reemit_notes).
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(3) All other notes (e.g. INSN_DELETED): Before scheduling a block,
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these notes are put in a list (in rm_other_notes() and
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unlink_other_notes ()). After scheduling the block, these notes are
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inserted at the beginning of the block (in schedule_block()). */
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static rtx unlink_other_notes PARAMS ((rtx, rtx));
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static rtx unlink_line_notes PARAMS ((rtx, rtx));
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static rtx reemit_notes PARAMS ((rtx, rtx));
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static rtx *ready_lastpos PARAMS ((struct ready_list *));
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static void ready_sort PARAMS ((struct ready_list *));
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static rtx ready_remove_first PARAMS ((struct ready_list *));
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static void queue_to_ready PARAMS ((struct ready_list *));
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static void debug_ready_list PARAMS ((struct ready_list *));
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static rtx move_insn1 PARAMS ((rtx, rtx));
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static rtx move_insn PARAMS ((rtx, rtx));
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#endif /* INSN_SCHEDULING */
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/* Point to state used for the current scheduling pass. */
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struct sched_info *current_sched_info;
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#ifndef INSN_SCHEDULING
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void
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schedule_insns (dump_file)
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FILE *dump_file ATTRIBUTE_UNUSED;
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{
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}
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#else
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/* Pointer to the last instruction scheduled. Used by rank_for_schedule,
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so that insns independent of the last scheduled insn will be preferred
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over dependent instructions. */
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static rtx last_scheduled_insn;
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/* Compute the function units used by INSN. This caches the value
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returned by function_units_used. A function unit is encoded as the
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unit number if the value is non-negative and the compliment of a
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mask if the value is negative. A function unit index is the
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non-negative encoding. */
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HAIFA_INLINE int
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insn_unit (insn)
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rtx insn;
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{
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int unit = INSN_UNIT (insn);
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if (unit == 0)
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{
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recog_memoized (insn);
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/* A USE insn, or something else we don't need to understand.
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We can't pass these directly to function_units_used because it will
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trigger a fatal error for unrecognizable insns. */
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if (INSN_CODE (insn) < 0)
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unit = -1;
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else
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{
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unit = function_units_used (insn);
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/* Increment non-negative values so we can cache zero. */
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if (unit >= 0)
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unit++;
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}
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/* We only cache 16 bits of the result, so if the value is out of
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range, don't cache it. */
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if (FUNCTION_UNITS_SIZE < HOST_BITS_PER_SHORT
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|| unit >= 0
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|| (unit & ~((1 << (HOST_BITS_PER_SHORT - 1)) - 1)) == 0)
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INSN_UNIT (insn) = unit;
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}
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return (unit > 0 ? unit - 1 : unit);
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}
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/* Compute the blockage range for executing INSN on UNIT. This caches
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the value returned by the blockage_range_function for the unit.
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These values are encoded in an int where the upper half gives the
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minimum value and the lower half gives the maximum value. */
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HAIFA_INLINE static unsigned int
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blockage_range (unit, insn)
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int unit;
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rtx insn;
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{
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unsigned int blockage = INSN_BLOCKAGE (insn);
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unsigned int range;
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if ((int) UNIT_BLOCKED (blockage) != unit + 1)
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{
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range = function_units[unit].blockage_range_function (insn);
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/* We only cache the blockage range for one unit and then only if
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the values fit. */
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if (HOST_BITS_PER_INT >= UNIT_BITS + 2 * BLOCKAGE_BITS)
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INSN_BLOCKAGE (insn) = ENCODE_BLOCKAGE (unit + 1, range);
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}
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else
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range = BLOCKAGE_RANGE (blockage);
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return range;
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}
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/* A vector indexed by function unit instance giving the last insn to use
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the unit. The value of the function unit instance index for unit U
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instance I is (U + I * FUNCTION_UNITS_SIZE). */
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static rtx unit_last_insn[FUNCTION_UNITS_SIZE * MAX_MULTIPLICITY];
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/* A vector indexed by function unit instance giving the minimum time when
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the unit will unblock based on the maximum blockage cost. */
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static int unit_tick[FUNCTION_UNITS_SIZE * MAX_MULTIPLICITY];
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/* A vector indexed by function unit number giving the number of insns
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that remain to use the unit. */
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static int unit_n_insns[FUNCTION_UNITS_SIZE];
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/* Access the unit_last_insn array. Used by the visualization code. */
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rtx
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get_unit_last_insn (instance)
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int instance;
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{
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return unit_last_insn[instance];
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}
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/* Reset the function unit state to the null state. */
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static void
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clear_units ()
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{
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memset ((char *) unit_last_insn, 0, sizeof (unit_last_insn));
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memset ((char *) unit_tick, 0, sizeof (unit_tick));
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memset ((char *) unit_n_insns, 0, sizeof (unit_n_insns));
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}
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/* Return the issue-delay of an insn. */
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HAIFA_INLINE int
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insn_issue_delay (insn)
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rtx insn;
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{
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int i, delay = 0;
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int unit = insn_unit (insn);
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/* Efficiency note: in fact, we are working 'hard' to compute a
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value that was available in md file, and is not available in
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function_units[] structure. It would be nice to have this
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value there, too. */
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if (unit >= 0)
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{
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if (function_units[unit].blockage_range_function &&
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function_units[unit].blockage_function)
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delay = function_units[unit].blockage_function (insn, insn);
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}
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else
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for (i = 0, unit = ~unit; unit; i++, unit >>= 1)
|
||
if ((unit & 1) != 0 && function_units[i].blockage_range_function
|
||
&& function_units[i].blockage_function)
|
||
delay = MAX (delay, function_units[i].blockage_function (insn, insn));
|
||
|
||
return delay;
|
||
}
|
||
|
||
/* Return the actual hazard cost of executing INSN on the unit UNIT,
|
||
instance INSTANCE at time CLOCK if the previous actual hazard cost
|
||
was COST. */
|
||
|
||
HAIFA_INLINE int
|
||
actual_hazard_this_instance (unit, instance, insn, clock, cost)
|
||
int unit, instance, clock, cost;
|
||
rtx insn;
|
||
{
|
||
int tick = unit_tick[instance]; /* Issue time of the last issued insn. */
|
||
|
||
if (tick - clock > cost)
|
||
{
|
||
/* The scheduler is operating forward, so unit's last insn is the
|
||
executing insn and INSN is the candidate insn. We want a
|
||
more exact measure of the blockage if we execute INSN at CLOCK
|
||
given when we committed the execution of the unit's last insn.
|
||
|
||
The blockage value is given by either the unit's max blockage
|
||
constant, blockage range function, or blockage function. Use
|
||
the most exact form for the given unit. */
|
||
|
||
if (function_units[unit].blockage_range_function)
|
||
{
|
||
if (function_units[unit].blockage_function)
|
||
tick += (function_units[unit].blockage_function
|
||
(unit_last_insn[instance], insn)
|
||
- function_units[unit].max_blockage);
|
||
else
|
||
tick += ((int) MAX_BLOCKAGE_COST (blockage_range (unit, insn))
|
||
- function_units[unit].max_blockage);
|
||
}
|
||
if (tick - clock > cost)
|
||
cost = tick - clock;
|
||
}
|
||
return cost;
|
||
}
|
||
|
||
/* Record INSN as having begun execution on the units encoded by UNIT at
|
||
time CLOCK. */
|
||
|
||
HAIFA_INLINE static void
|
||
schedule_unit (unit, insn, clock)
|
||
int unit, clock;
|
||
rtx insn;
|
||
{
|
||
int i;
|
||
|
||
if (unit >= 0)
|
||
{
|
||
int instance = unit;
|
||
#if MAX_MULTIPLICITY > 1
|
||
/* Find the first free instance of the function unit and use that
|
||
one. We assume that one is free. */
|
||
for (i = function_units[unit].multiplicity - 1; i > 0; i--)
|
||
{
|
||
if (!actual_hazard_this_instance (unit, instance, insn, clock, 0))
|
||
break;
|
||
instance += FUNCTION_UNITS_SIZE;
|
||
}
|
||
#endif
|
||
unit_last_insn[instance] = insn;
|
||
unit_tick[instance] = (clock + function_units[unit].max_blockage);
|
||
}
|
||
else
|
||
for (i = 0, unit = ~unit; unit; i++, unit >>= 1)
|
||
if ((unit & 1) != 0)
|
||
schedule_unit (i, insn, clock);
|
||
}
|
||
|
||
/* Return the actual hazard cost of executing INSN on the units encoded by
|
||
UNIT at time CLOCK if the previous actual hazard cost was COST. */
|
||
|
||
HAIFA_INLINE static int
|
||
actual_hazard (unit, insn, clock, cost)
|
||
int unit, clock, cost;
|
||
rtx insn;
|
||
{
|
||
int i;
|
||
|
||
if (unit >= 0)
|
||
{
|
||
/* Find the instance of the function unit with the minimum hazard. */
|
||
int instance = unit;
|
||
int best_cost = actual_hazard_this_instance (unit, instance, insn,
|
||
clock, cost);
|
||
#if MAX_MULTIPLICITY > 1
|
||
int this_cost;
|
||
|
||
if (best_cost > cost)
|
||
{
|
||
for (i = function_units[unit].multiplicity - 1; i > 0; i--)
|
||
{
|
||
instance += FUNCTION_UNITS_SIZE;
|
||
this_cost = actual_hazard_this_instance (unit, instance, insn,
|
||
clock, cost);
|
||
if (this_cost < best_cost)
|
||
{
|
||
best_cost = this_cost;
|
||
if (this_cost <= cost)
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
#endif
|
||
cost = MAX (cost, best_cost);
|
||
}
|
||
else
|
||
for (i = 0, unit = ~unit; unit; i++, unit >>= 1)
|
||
if ((unit & 1) != 0)
|
||
cost = actual_hazard (i, insn, clock, cost);
|
||
|
||
return cost;
|
||
}
|
||
|
||
/* Return the potential hazard cost of executing an instruction on the
|
||
units encoded by UNIT if the previous potential hazard cost was COST.
|
||
An insn with a large blockage time is chosen in preference to one
|
||
with a smaller time; an insn that uses a unit that is more likely
|
||
to be used is chosen in preference to one with a unit that is less
|
||
used. We are trying to minimize a subsequent actual hazard. */
|
||
|
||
HAIFA_INLINE static int
|
||
potential_hazard (unit, insn, cost)
|
||
int unit, cost;
|
||
rtx insn;
|
||
{
|
||
int i, ncost;
|
||
unsigned int minb, maxb;
|
||
|
||
if (unit >= 0)
|
||
{
|
||
minb = maxb = function_units[unit].max_blockage;
|
||
if (maxb > 1)
|
||
{
|
||
if (function_units[unit].blockage_range_function)
|
||
{
|
||
maxb = minb = blockage_range (unit, insn);
|
||
maxb = MAX_BLOCKAGE_COST (maxb);
|
||
minb = MIN_BLOCKAGE_COST (minb);
|
||
}
|
||
|
||
if (maxb > 1)
|
||
{
|
||
/* Make the number of instructions left dominate. Make the
|
||
minimum delay dominate the maximum delay. If all these
|
||
are the same, use the unit number to add an arbitrary
|
||
ordering. Other terms can be added. */
|
||
ncost = minb * 0x40 + maxb;
|
||
ncost *= (unit_n_insns[unit] - 1) * 0x1000 + unit;
|
||
if (ncost > cost)
|
||
cost = ncost;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
for (i = 0, unit = ~unit; unit; i++, unit >>= 1)
|
||
if ((unit & 1) != 0)
|
||
cost = potential_hazard (i, insn, cost);
|
||
|
||
return cost;
|
||
}
|
||
|
||
/* Compute cost of executing INSN given the dependence LINK on the insn USED.
|
||
This is the number of cycles between instruction issue and
|
||
instruction results. */
|
||
|
||
HAIFA_INLINE int
|
||
insn_cost (insn, link, used)
|
||
rtx insn, link, used;
|
||
{
|
||
int cost = INSN_COST (insn);
|
||
|
||
if (cost == 0)
|
||
{
|
||
recog_memoized (insn);
|
||
|
||
/* A USE insn, or something else we don't need to understand.
|
||
We can't pass these directly to result_ready_cost because it will
|
||
trigger a fatal error for unrecognizable insns. */
|
||
if (INSN_CODE (insn) < 0)
|
||
{
|
||
INSN_COST (insn) = 1;
|
||
return 1;
|
||
}
|
||
else
|
||
{
|
||
cost = result_ready_cost (insn);
|
||
|
||
if (cost < 1)
|
||
cost = 1;
|
||
|
||
INSN_COST (insn) = cost;
|
||
}
|
||
}
|
||
|
||
/* In this case estimate cost without caring how insn is used. */
|
||
if (link == 0 && used == 0)
|
||
return cost;
|
||
|
||
/* A USE insn should never require the value used to be computed. This
|
||
allows the computation of a function's result and parameter values to
|
||
overlap the return and call. */
|
||
recog_memoized (used);
|
||
if (INSN_CODE (used) < 0)
|
||
LINK_COST_FREE (link) = 1;
|
||
|
||
/* If some dependencies vary the cost, compute the adjustment. Most
|
||
commonly, the adjustment is complete: either the cost is ignored
|
||
(in the case of an output- or anti-dependence), or the cost is
|
||
unchanged. These values are cached in the link as LINK_COST_FREE
|
||
and LINK_COST_ZERO. */
|
||
|
||
if (LINK_COST_FREE (link))
|
||
cost = 0;
|
||
else if (!LINK_COST_ZERO (link) && targetm.sched.adjust_cost)
|
||
{
|
||
int ncost = (*targetm.sched.adjust_cost) (used, link, insn, cost);
|
||
|
||
if (ncost < 1)
|
||
{
|
||
LINK_COST_FREE (link) = 1;
|
||
ncost = 0;
|
||
}
|
||
if (cost == ncost)
|
||
LINK_COST_ZERO (link) = 1;
|
||
cost = ncost;
|
||
}
|
||
|
||
return cost;
|
||
}
|
||
|
||
/* Compute the priority number for INSN. */
|
||
|
||
static int
|
||
priority (insn)
|
||
rtx insn;
|
||
{
|
||
rtx link;
|
||
|
||
if (! INSN_P (insn))
|
||
return 0;
|
||
|
||
if (! INSN_PRIORITY_KNOWN (insn))
|
||
{
|
||
int this_priority = 0;
|
||
|
||
if (INSN_DEPEND (insn) == 0)
|
||
this_priority = insn_cost (insn, 0, 0);
|
||
else
|
||
{
|
||
for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1))
|
||
{
|
||
rtx next;
|
||
int next_priority;
|
||
|
||
if (RTX_INTEGRATED_P (link))
|
||
continue;
|
||
|
||
next = XEXP (link, 0);
|
||
|
||
/* Critical path is meaningful in block boundaries only. */
|
||
if (! (*current_sched_info->contributes_to_priority) (next, insn))
|
||
continue;
|
||
|
||
next_priority = insn_cost (insn, link, next) + priority (next);
|
||
if (next_priority > this_priority)
|
||
this_priority = next_priority;
|
||
}
|
||
}
|
||
INSN_PRIORITY (insn) = this_priority;
|
||
INSN_PRIORITY_KNOWN (insn) = 1;
|
||
}
|
||
|
||
return INSN_PRIORITY (insn);
|
||
}
|
||
|
||
/* Macros and functions for keeping the priority queue sorted, and
|
||
dealing with queueing and dequeueing of instructions. */
|
||
|
||
#define SCHED_SORT(READY, N_READY) \
|
||
do { if ((N_READY) == 2) \
|
||
swap_sort (READY, N_READY); \
|
||
else if ((N_READY) > 2) \
|
||
qsort (READY, N_READY, sizeof (rtx), rank_for_schedule); } \
|
||
while (0)
|
||
|
||
/* Returns a positive value if x is preferred; returns a negative value if
|
||
y is preferred. Should never return 0, since that will make the sort
|
||
unstable. */
|
||
|
||
static int
|
||
rank_for_schedule (x, y)
|
||
const PTR x;
|
||
const PTR y;
|
||
{
|
||
rtx tmp = *(const rtx *) y;
|
||
rtx tmp2 = *(const rtx *) x;
|
||
rtx link;
|
||
int tmp_class, tmp2_class, depend_count1, depend_count2;
|
||
int val, priority_val, weight_val, info_val;
|
||
|
||
/* Prefer insn with higher priority. */
|
||
priority_val = INSN_PRIORITY (tmp2) - INSN_PRIORITY (tmp);
|
||
if (priority_val)
|
||
return priority_val;
|
||
|
||
/* Prefer an insn with smaller contribution to registers-pressure. */
|
||
if (!reload_completed &&
|
||
(weight_val = INSN_REG_WEIGHT (tmp) - INSN_REG_WEIGHT (tmp2)))
|
||
return (weight_val);
|
||
|
||
info_val = (*current_sched_info->rank) (tmp, tmp2);
|
||
if (info_val)
|
||
return info_val;
|
||
|
||
/* Compare insns based on their relation to the last-scheduled-insn. */
|
||
if (last_scheduled_insn)
|
||
{
|
||
/* Classify the instructions into three classes:
|
||
1) Data dependent on last schedule insn.
|
||
2) Anti/Output dependent on last scheduled insn.
|
||
3) Independent of last scheduled insn, or has latency of one.
|
||
Choose the insn from the highest numbered class if different. */
|
||
link = find_insn_list (tmp, INSN_DEPEND (last_scheduled_insn));
|
||
if (link == 0 || insn_cost (last_scheduled_insn, link, tmp) == 1)
|
||
tmp_class = 3;
|
||
else if (REG_NOTE_KIND (link) == 0) /* Data dependence. */
|
||
tmp_class = 1;
|
||
else
|
||
tmp_class = 2;
|
||
|
||
link = find_insn_list (tmp2, INSN_DEPEND (last_scheduled_insn));
|
||
if (link == 0 || insn_cost (last_scheduled_insn, link, tmp2) == 1)
|
||
tmp2_class = 3;
|
||
else if (REG_NOTE_KIND (link) == 0) /* Data dependence. */
|
||
tmp2_class = 1;
|
||
else
|
||
tmp2_class = 2;
|
||
|
||
if ((val = tmp2_class - tmp_class))
|
||
return val;
|
||
}
|
||
|
||
/* Prefer the insn which has more later insns that depend on it.
|
||
This gives the scheduler more freedom when scheduling later
|
||
instructions at the expense of added register pressure. */
|
||
depend_count1 = 0;
|
||
for (link = INSN_DEPEND (tmp); link; link = XEXP (link, 1))
|
||
depend_count1++;
|
||
|
||
depend_count2 = 0;
|
||
for (link = INSN_DEPEND (tmp2); link; link = XEXP (link, 1))
|
||
depend_count2++;
|
||
|
||
val = depend_count2 - depend_count1;
|
||
if (val)
|
||
return val;
|
||
|
||
/* If insns are equally good, sort by INSN_LUID (original insn order),
|
||
so that we make the sort stable. This minimizes instruction movement,
|
||
thus minimizing sched's effect on debugging and cross-jumping. */
|
||
return INSN_LUID (tmp) - INSN_LUID (tmp2);
|
||
}
|
||
|
||
/* Resort the array A in which only element at index N may be out of order. */
|
||
|
||
HAIFA_INLINE static void
|
||
swap_sort (a, n)
|
||
rtx *a;
|
||
int n;
|
||
{
|
||
rtx insn = a[n - 1];
|
||
int i = n - 2;
|
||
|
||
while (i >= 0 && rank_for_schedule (a + i, &insn) >= 0)
|
||
{
|
||
a[i + 1] = a[i];
|
||
i -= 1;
|
||
}
|
||
a[i + 1] = insn;
|
||
}
|
||
|
||
/* Add INSN to the insn queue so that it can be executed at least
|
||
N_CYCLES after the currently executing insn. Preserve insns
|
||
chain for debugging purposes. */
|
||
|
||
HAIFA_INLINE static void
|
||
queue_insn (insn, n_cycles)
|
||
rtx insn;
|
||
int n_cycles;
|
||
{
|
||
int next_q = NEXT_Q_AFTER (q_ptr, n_cycles);
|
||
rtx link = alloc_INSN_LIST (insn, insn_queue[next_q]);
|
||
insn_queue[next_q] = link;
|
||
q_size += 1;
|
||
|
||
if (sched_verbose >= 2)
|
||
{
|
||
fprintf (sched_dump, ";;\t\tReady-->Q: insn %s: ",
|
||
(*current_sched_info->print_insn) (insn, 0));
|
||
|
||
fprintf (sched_dump, "queued for %d cycles.\n", n_cycles);
|
||
}
|
||
}
|
||
|
||
/* Return a pointer to the bottom of the ready list, i.e. the insn
|
||
with the lowest priority. */
|
||
|
||
HAIFA_INLINE static rtx *
|
||
ready_lastpos (ready)
|
||
struct ready_list *ready;
|
||
{
|
||
if (ready->n_ready == 0)
|
||
abort ();
|
||
return ready->vec + ready->first - ready->n_ready + 1;
|
||
}
|
||
|
||
/* Add an element INSN to the ready list so that it ends up with the lowest
|
||
priority. */
|
||
|
||
HAIFA_INLINE void
|
||
ready_add (ready, insn)
|
||
struct ready_list *ready;
|
||
rtx insn;
|
||
{
|
||
if (ready->first == ready->n_ready)
|
||
{
|
||
memmove (ready->vec + ready->veclen - ready->n_ready,
|
||
ready_lastpos (ready),
|
||
ready->n_ready * sizeof (rtx));
|
||
ready->first = ready->veclen - 1;
|
||
}
|
||
ready->vec[ready->first - ready->n_ready] = insn;
|
||
ready->n_ready++;
|
||
}
|
||
|
||
/* Remove the element with the highest priority from the ready list and
|
||
return it. */
|
||
|
||
HAIFA_INLINE static rtx
|
||
ready_remove_first (ready)
|
||
struct ready_list *ready;
|
||
{
|
||
rtx t;
|
||
if (ready->n_ready == 0)
|
||
abort ();
|
||
t = ready->vec[ready->first--];
|
||
ready->n_ready--;
|
||
/* If the queue becomes empty, reset it. */
|
||
if (ready->n_ready == 0)
|
||
ready->first = ready->veclen - 1;
|
||
return t;
|
||
}
|
||
|
||
/* Sort the ready list READY by ascending priority, using the SCHED_SORT
|
||
macro. */
|
||
|
||
HAIFA_INLINE static void
|
||
ready_sort (ready)
|
||
struct ready_list *ready;
|
||
{
|
||
rtx *first = ready_lastpos (ready);
|
||
SCHED_SORT (first, ready->n_ready);
|
||
}
|
||
|
||
/* PREV is an insn that is ready to execute. Adjust its priority if that
|
||
will help shorten or lengthen register lifetimes as appropriate. Also
|
||
provide a hook for the target to tweek itself. */
|
||
|
||
HAIFA_INLINE static void
|
||
adjust_priority (prev)
|
||
rtx prev;
|
||
{
|
||
/* ??? There used to be code here to try and estimate how an insn
|
||
affected register lifetimes, but it did it by looking at REG_DEAD
|
||
notes, which we removed in schedule_region. Nor did it try to
|
||
take into account register pressure or anything useful like that.
|
||
|
||
Revisit when we have a machine model to work with and not before. */
|
||
|
||
if (targetm.sched.adjust_priority)
|
||
INSN_PRIORITY (prev) =
|
||
(*targetm.sched.adjust_priority) (prev, INSN_PRIORITY (prev));
|
||
}
|
||
|
||
/* Clock at which the previous instruction was issued. */
|
||
static int last_clock_var;
|
||
|
||
/* INSN is the "currently executing insn". Launch each insn which was
|
||
waiting on INSN. READY is the ready list which contains the insns
|
||
that are ready to fire. CLOCK is the current cycle.
|
||
*/
|
||
|
||
static void
|
||
schedule_insn (insn, ready, clock)
|
||
rtx insn;
|
||
struct ready_list *ready;
|
||
int clock;
|
||
{
|
||
rtx link;
|
||
int unit;
|
||
|
||
unit = insn_unit (insn);
|
||
|
||
if (sched_verbose >= 2)
|
||
{
|
||
fprintf (sched_dump, ";;\t\t--> scheduling insn <<<%d>>> on unit ",
|
||
INSN_UID (insn));
|
||
insn_print_units (insn);
|
||
fprintf (sched_dump, "\n");
|
||
}
|
||
|
||
if (sched_verbose && unit == -1)
|
||
visualize_no_unit (insn);
|
||
|
||
if (MAX_BLOCKAGE > 1 || issue_rate > 1 || sched_verbose)
|
||
schedule_unit (unit, insn, clock);
|
||
|
||
if (INSN_DEPEND (insn) == 0)
|
||
return;
|
||
|
||
for (link = INSN_DEPEND (insn); link != 0; link = XEXP (link, 1))
|
||
{
|
||
rtx next = XEXP (link, 0);
|
||
int cost = insn_cost (insn, link, next);
|
||
|
||
INSN_TICK (next) = MAX (INSN_TICK (next), clock + cost);
|
||
|
||
if ((INSN_DEP_COUNT (next) -= 1) == 0)
|
||
{
|
||
int effective_cost = INSN_TICK (next) - clock;
|
||
|
||
if (! (*current_sched_info->new_ready) (next))
|
||
continue;
|
||
|
||
if (sched_verbose >= 2)
|
||
{
|
||
fprintf (sched_dump, ";;\t\tdependences resolved: insn %s ",
|
||
(*current_sched_info->print_insn) (next, 0));
|
||
|
||
if (effective_cost < 1)
|
||
fprintf (sched_dump, "into ready\n");
|
||
else
|
||
fprintf (sched_dump, "into queue with cost=%d\n", effective_cost);
|
||
}
|
||
|
||
/* Adjust the priority of NEXT and either put it on the ready
|
||
list or queue it. */
|
||
adjust_priority (next);
|
||
if (effective_cost < 1)
|
||
ready_add (ready, next);
|
||
else
|
||
queue_insn (next, effective_cost);
|
||
}
|
||
}
|
||
|
||
/* Annotate the instruction with issue information -- TImode
|
||
indicates that the instruction is expected not to be able
|
||
to issue on the same cycle as the previous insn. A machine
|
||
may use this information to decide how the instruction should
|
||
be aligned. */
|
||
if (reload_completed && issue_rate > 1)
|
||
{
|
||
PUT_MODE (insn, clock > last_clock_var ? TImode : VOIDmode);
|
||
last_clock_var = clock;
|
||
}
|
||
}
|
||
|
||
/* Functions for handling of notes. */
|
||
|
||
/* Delete notes beginning with INSN and put them in the chain
|
||
of notes ended by NOTE_LIST.
|
||
Returns the insn following the notes. */
|
||
|
||
static rtx
|
||
unlink_other_notes (insn, tail)
|
||
rtx insn, tail;
|
||
{
|
||
rtx prev = PREV_INSN (insn);
|
||
|
||
while (insn != tail && GET_CODE (insn) == NOTE)
|
||
{
|
||
rtx next = NEXT_INSN (insn);
|
||
/* Delete the note from its current position. */
|
||
if (prev)
|
||
NEXT_INSN (prev) = next;
|
||
if (next)
|
||
PREV_INSN (next) = prev;
|
||
|
||
/* See sched_analyze to see how these are handled. */
|
||
if (NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_BEG
|
||
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_LOOP_END
|
||
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_RANGE_BEG
|
||
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_RANGE_END
|
||
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_EH_REGION_BEG
|
||
&& NOTE_LINE_NUMBER (insn) != NOTE_INSN_EH_REGION_END)
|
||
{
|
||
/* Insert the note at the end of the notes list. */
|
||
PREV_INSN (insn) = note_list;
|
||
if (note_list)
|
||
NEXT_INSN (note_list) = insn;
|
||
note_list = insn;
|
||
}
|
||
|
||
insn = next;
|
||
}
|
||
return insn;
|
||
}
|
||
|
||
/* Delete line notes beginning with INSN. Record line-number notes so
|
||
they can be reused. Returns the insn following the notes. */
|
||
|
||
static rtx
|
||
unlink_line_notes (insn, tail)
|
||
rtx insn, tail;
|
||
{
|
||
rtx prev = PREV_INSN (insn);
|
||
|
||
while (insn != tail && GET_CODE (insn) == NOTE)
|
||
{
|
||
rtx next = NEXT_INSN (insn);
|
||
|
||
if (write_symbols != NO_DEBUG && NOTE_LINE_NUMBER (insn) > 0)
|
||
{
|
||
/* Delete the note from its current position. */
|
||
if (prev)
|
||
NEXT_INSN (prev) = next;
|
||
if (next)
|
||
PREV_INSN (next) = prev;
|
||
|
||
/* Record line-number notes so they can be reused. */
|
||
LINE_NOTE (insn) = insn;
|
||
}
|
||
else
|
||
prev = insn;
|
||
|
||
insn = next;
|
||
}
|
||
return insn;
|
||
}
|
||
|
||
/* Return the head and tail pointers of BB. */
|
||
|
||
void
|
||
get_block_head_tail (b, headp, tailp)
|
||
int b;
|
||
rtx *headp;
|
||
rtx *tailp;
|
||
{
|
||
/* HEAD and TAIL delimit the basic block being scheduled. */
|
||
rtx head = BLOCK_HEAD (b);
|
||
rtx tail = BLOCK_END (b);
|
||
|
||
/* Don't include any notes or labels at the beginning of the
|
||
basic block, or notes at the ends of basic blocks. */
|
||
while (head != tail)
|
||
{
|
||
if (GET_CODE (head) == NOTE)
|
||
head = NEXT_INSN (head);
|
||
else if (GET_CODE (tail) == NOTE)
|
||
tail = PREV_INSN (tail);
|
||
else if (GET_CODE (head) == CODE_LABEL)
|
||
head = NEXT_INSN (head);
|
||
else
|
||
break;
|
||
}
|
||
|
||
*headp = head;
|
||
*tailp = tail;
|
||
}
|
||
|
||
/* Return nonzero if there are no real insns in the range [ HEAD, TAIL ]. */
|
||
|
||
int
|
||
no_real_insns_p (head, tail)
|
||
rtx head, tail;
|
||
{
|
||
while (head != NEXT_INSN (tail))
|
||
{
|
||
if (GET_CODE (head) != NOTE && GET_CODE (head) != CODE_LABEL)
|
||
return 0;
|
||
head = NEXT_INSN (head);
|
||
}
|
||
return 1;
|
||
}
|
||
|
||
/* Delete line notes from one block. Save them so they can be later restored
|
||
(in restore_line_notes). HEAD and TAIL are the boundaries of the
|
||
block in which notes should be processed. */
|
||
|
||
void
|
||
rm_line_notes (head, tail)
|
||
rtx head, tail;
|
||
{
|
||
rtx next_tail;
|
||
rtx insn;
|
||
|
||
next_tail = NEXT_INSN (tail);
|
||
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
|
||
{
|
||
rtx prev;
|
||
|
||
/* Farm out notes, and maybe save them in NOTE_LIST.
|
||
This is needed to keep the debugger from
|
||
getting completely deranged. */
|
||
if (GET_CODE (insn) == NOTE)
|
||
{
|
||
prev = insn;
|
||
insn = unlink_line_notes (insn, next_tail);
|
||
|
||
if (prev == tail)
|
||
abort ();
|
||
if (prev == head)
|
||
abort ();
|
||
if (insn == next_tail)
|
||
abort ();
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Save line number notes for each insn in block B. HEAD and TAIL are
|
||
the boundaries of the block in which notes should be processed. */
|
||
|
||
void
|
||
save_line_notes (b, head, tail)
|
||
int b;
|
||
rtx head, tail;
|
||
{
|
||
rtx next_tail;
|
||
|
||
/* We must use the true line number for the first insn in the block
|
||
that was computed and saved at the start of this pass. We can't
|
||
use the current line number, because scheduling of the previous
|
||
block may have changed the current line number. */
|
||
|
||
rtx line = line_note_head[b];
|
||
rtx insn;
|
||
|
||
next_tail = NEXT_INSN (tail);
|
||
|
||
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
|
||
if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
|
||
line = insn;
|
||
else
|
||
LINE_NOTE (insn) = line;
|
||
}
|
||
|
||
/* After a block was scheduled, insert line notes into the insns list.
|
||
HEAD and TAIL are the boundaries of the block in which notes should
|
||
be processed. */
|
||
|
||
void
|
||
restore_line_notes (head, tail)
|
||
rtx head, tail;
|
||
{
|
||
rtx line, note, prev, new;
|
||
int added_notes = 0;
|
||
rtx next_tail, insn;
|
||
|
||
head = head;
|
||
next_tail = NEXT_INSN (tail);
|
||
|
||
/* Determine the current line-number. We want to know the current
|
||
line number of the first insn of the block here, in case it is
|
||
different from the true line number that was saved earlier. If
|
||
different, then we need a line number note before the first insn
|
||
of this block. If it happens to be the same, then we don't want to
|
||
emit another line number note here. */
|
||
for (line = head; line; line = PREV_INSN (line))
|
||
if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0)
|
||
break;
|
||
|
||
/* Walk the insns keeping track of the current line-number and inserting
|
||
the line-number notes as needed. */
|
||
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
|
||
if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
|
||
line = insn;
|
||
/* This used to emit line number notes before every non-deleted note.
|
||
However, this confuses a debugger, because line notes not separated
|
||
by real instructions all end up at the same address. I can find no
|
||
use for line number notes before other notes, so none are emitted. */
|
||
else if (GET_CODE (insn) != NOTE
|
||
&& INSN_UID (insn) < old_max_uid
|
||
&& (note = LINE_NOTE (insn)) != 0
|
||
&& note != line
|
||
&& (line == 0
|
||
|| NOTE_LINE_NUMBER (note) != NOTE_LINE_NUMBER (line)
|
||
|| NOTE_SOURCE_FILE (note) != NOTE_SOURCE_FILE (line)))
|
||
{
|
||
line = note;
|
||
prev = PREV_INSN (insn);
|
||
if (LINE_NOTE (note))
|
||
{
|
||
/* Re-use the original line-number note. */
|
||
LINE_NOTE (note) = 0;
|
||
PREV_INSN (note) = prev;
|
||
NEXT_INSN (prev) = note;
|
||
PREV_INSN (insn) = note;
|
||
NEXT_INSN (note) = insn;
|
||
}
|
||
else
|
||
{
|
||
added_notes++;
|
||
new = emit_note_after (NOTE_LINE_NUMBER (note), prev);
|
||
NOTE_SOURCE_FILE (new) = NOTE_SOURCE_FILE (note);
|
||
RTX_INTEGRATED_P (new) = RTX_INTEGRATED_P (note);
|
||
}
|
||
}
|
||
if (sched_verbose && added_notes)
|
||
fprintf (sched_dump, ";; added %d line-number notes\n", added_notes);
|
||
}
|
||
|
||
/* After scheduling the function, delete redundant line notes from the
|
||
insns list. */
|
||
|
||
void
|
||
rm_redundant_line_notes ()
|
||
{
|
||
rtx line = 0;
|
||
rtx insn = get_insns ();
|
||
int active_insn = 0;
|
||
int notes = 0;
|
||
|
||
/* Walk the insns deleting redundant line-number notes. Many of these
|
||
are already present. The remainder tend to occur at basic
|
||
block boundaries. */
|
||
for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
|
||
if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
|
||
{
|
||
/* If there are no active insns following, INSN is redundant. */
|
||
if (active_insn == 0)
|
||
{
|
||
notes++;
|
||
NOTE_SOURCE_FILE (insn) = 0;
|
||
NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
|
||
}
|
||
/* If the line number is unchanged, LINE is redundant. */
|
||
else if (line
|
||
&& NOTE_LINE_NUMBER (line) == NOTE_LINE_NUMBER (insn)
|
||
&& NOTE_SOURCE_FILE (line) == NOTE_SOURCE_FILE (insn))
|
||
{
|
||
notes++;
|
||
NOTE_SOURCE_FILE (line) = 0;
|
||
NOTE_LINE_NUMBER (line) = NOTE_INSN_DELETED;
|
||
line = insn;
|
||
}
|
||
else
|
||
line = insn;
|
||
active_insn = 0;
|
||
}
|
||
else if (!((GET_CODE (insn) == NOTE
|
||
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_DELETED)
|
||
|| (GET_CODE (insn) == INSN
|
||
&& (GET_CODE (PATTERN (insn)) == USE
|
||
|| GET_CODE (PATTERN (insn)) == CLOBBER))))
|
||
active_insn++;
|
||
|
||
if (sched_verbose && notes)
|
||
fprintf (sched_dump, ";; deleted %d line-number notes\n", notes);
|
||
}
|
||
|
||
/* Delete notes between HEAD and TAIL and put them in the chain
|
||
of notes ended by NOTE_LIST. */
|
||
|
||
void
|
||
rm_other_notes (head, tail)
|
||
rtx head;
|
||
rtx tail;
|
||
{
|
||
rtx next_tail;
|
||
rtx insn;
|
||
|
||
note_list = 0;
|
||
if (head == tail && (! INSN_P (head)))
|
||
return;
|
||
|
||
next_tail = NEXT_INSN (tail);
|
||
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
|
||
{
|
||
rtx prev;
|
||
|
||
/* Farm out notes, and maybe save them in NOTE_LIST.
|
||
This is needed to keep the debugger from
|
||
getting completely deranged. */
|
||
if (GET_CODE (insn) == NOTE)
|
||
{
|
||
prev = insn;
|
||
|
||
insn = unlink_other_notes (insn, next_tail);
|
||
|
||
if (prev == tail)
|
||
abort ();
|
||
if (prev == head)
|
||
abort ();
|
||
if (insn == next_tail)
|
||
abort ();
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Functions for computation of registers live/usage info. */
|
||
|
||
/* Calculate INSN_REG_WEIGHT for all insns of a block. */
|
||
|
||
static void
|
||
find_insn_reg_weight (b)
|
||
int b;
|
||
{
|
||
rtx insn, next_tail, head, tail;
|
||
|
||
get_block_head_tail (b, &head, &tail);
|
||
next_tail = NEXT_INSN (tail);
|
||
|
||
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
|
||
{
|
||
int reg_weight = 0;
|
||
rtx x;
|
||
|
||
/* Handle register life information. */
|
||
if (! INSN_P (insn))
|
||
continue;
|
||
|
||
/* Increment weight for each register born here. */
|
||
x = PATTERN (insn);
|
||
if ((GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
|
||
&& register_operand (SET_DEST (x), VOIDmode))
|
||
reg_weight++;
|
||
else if (GET_CODE (x) == PARALLEL)
|
||
{
|
||
int j;
|
||
for (j = XVECLEN (x, 0) - 1; j >= 0; j--)
|
||
{
|
||
x = XVECEXP (PATTERN (insn), 0, j);
|
||
if ((GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
|
||
&& register_operand (SET_DEST (x), VOIDmode))
|
||
reg_weight++;
|
||
}
|
||
}
|
||
|
||
/* Decrement weight for each register that dies here. */
|
||
for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
|
||
{
|
||
if (REG_NOTE_KIND (x) == REG_DEAD
|
||
|| REG_NOTE_KIND (x) == REG_UNUSED)
|
||
reg_weight--;
|
||
}
|
||
|
||
INSN_REG_WEIGHT (insn) = reg_weight;
|
||
}
|
||
}
|
||
|
||
/* Scheduling clock, modified in schedule_block() and queue_to_ready (). */
|
||
static int clock_var;
|
||
|
||
/* Move insns that became ready to fire from queue to ready list. */
|
||
|
||
static void
|
||
queue_to_ready (ready)
|
||
struct ready_list *ready;
|
||
{
|
||
rtx insn;
|
||
rtx link;
|
||
|
||
q_ptr = NEXT_Q (q_ptr);
|
||
|
||
/* Add all pending insns that can be scheduled without stalls to the
|
||
ready list. */
|
||
for (link = insn_queue[q_ptr]; link; link = XEXP (link, 1))
|
||
{
|
||
insn = XEXP (link, 0);
|
||
q_size -= 1;
|
||
|
||
if (sched_verbose >= 2)
|
||
fprintf (sched_dump, ";;\t\tQ-->Ready: insn %s: ",
|
||
(*current_sched_info->print_insn) (insn, 0));
|
||
|
||
ready_add (ready, insn);
|
||
if (sched_verbose >= 2)
|
||
fprintf (sched_dump, "moving to ready without stalls\n");
|
||
}
|
||
insn_queue[q_ptr] = 0;
|
||
|
||
/* If there are no ready insns, stall until one is ready and add all
|
||
of the pending insns at that point to the ready list. */
|
||
if (ready->n_ready == 0)
|
||
{
|
||
int stalls;
|
||
|
||
for (stalls = 1; stalls < INSN_QUEUE_SIZE; stalls++)
|
||
{
|
||
if ((link = insn_queue[NEXT_Q_AFTER (q_ptr, stalls)]))
|
||
{
|
||
for (; link; link = XEXP (link, 1))
|
||
{
|
||
insn = XEXP (link, 0);
|
||
q_size -= 1;
|
||
|
||
if (sched_verbose >= 2)
|
||
fprintf (sched_dump, ";;\t\tQ-->Ready: insn %s: ",
|
||
(*current_sched_info->print_insn) (insn, 0));
|
||
|
||
ready_add (ready, insn);
|
||
if (sched_verbose >= 2)
|
||
fprintf (sched_dump, "moving to ready with %d stalls\n", stalls);
|
||
}
|
||
insn_queue[NEXT_Q_AFTER (q_ptr, stalls)] = 0;
|
||
|
||
if (ready->n_ready)
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (sched_verbose && stalls)
|
||
visualize_stall_cycles (stalls);
|
||
q_ptr = NEXT_Q_AFTER (q_ptr, stalls);
|
||
clock_var += stalls;
|
||
}
|
||
}
|
||
|
||
/* Print the ready list for debugging purposes. Callable from debugger. */
|
||
|
||
static void
|
||
debug_ready_list (ready)
|
||
struct ready_list *ready;
|
||
{
|
||
rtx *p;
|
||
int i;
|
||
|
||
if (ready->n_ready == 0)
|
||
return;
|
||
|
||
p = ready_lastpos (ready);
|
||
for (i = 0; i < ready->n_ready; i++)
|
||
fprintf (sched_dump, " %s", (*current_sched_info->print_insn) (p[i], 0));
|
||
fprintf (sched_dump, "\n");
|
||
}
|
||
|
||
/* move_insn1: Remove INSN from insn chain, and link it after LAST insn. */
|
||
|
||
static rtx
|
||
move_insn1 (insn, last)
|
||
rtx insn, last;
|
||
{
|
||
NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (insn);
|
||
PREV_INSN (NEXT_INSN (insn)) = PREV_INSN (insn);
|
||
|
||
NEXT_INSN (insn) = NEXT_INSN (last);
|
||
PREV_INSN (NEXT_INSN (last)) = insn;
|
||
|
||
NEXT_INSN (last) = insn;
|
||
PREV_INSN (insn) = last;
|
||
|
||
return insn;
|
||
}
|
||
|
||
/* Search INSN for REG_SAVE_NOTE note pairs for
|
||
NOTE_INSN_{LOOP,EHREGION}_{BEG,END}; and convert them back into
|
||
NOTEs. The REG_SAVE_NOTE note following first one is contains the
|
||
saved value for NOTE_BLOCK_NUMBER which is useful for
|
||
NOTE_INSN_EH_REGION_{BEG,END} NOTEs. LAST is the last instruction
|
||
output by the instruction scheduler. Return the new value of LAST. */
|
||
|
||
static rtx
|
||
reemit_notes (insn, last)
|
||
rtx insn;
|
||
rtx last;
|
||
{
|
||
rtx note, retval;
|
||
|
||
retval = last;
|
||
for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
|
||
{
|
||
if (REG_NOTE_KIND (note) == REG_SAVE_NOTE)
|
||
{
|
||
enum insn_note note_type = INTVAL (XEXP (note, 0));
|
||
|
||
if (note_type == NOTE_INSN_RANGE_BEG
|
||
|| note_type == NOTE_INSN_RANGE_END)
|
||
{
|
||
last = emit_note_before (note_type, last);
|
||
remove_note (insn, note);
|
||
note = XEXP (note, 1);
|
||
NOTE_RANGE_INFO (last) = XEXP (note, 0);
|
||
}
|
||
else
|
||
{
|
||
last = emit_note_before (note_type, last);
|
||
remove_note (insn, note);
|
||
note = XEXP (note, 1);
|
||
if (note_type == NOTE_INSN_EH_REGION_BEG
|
||
|| note_type == NOTE_INSN_EH_REGION_END)
|
||
NOTE_EH_HANDLER (last) = INTVAL (XEXP (note, 0));
|
||
}
|
||
remove_note (insn, note);
|
||
}
|
||
}
|
||
return retval;
|
||
}
|
||
|
||
/* Move INSN, and all insns which should be issued before it,
|
||
due to SCHED_GROUP_P flag. Reemit notes if needed.
|
||
|
||
Return the last insn emitted by the scheduler, which is the
|
||
return value from the first call to reemit_notes. */
|
||
|
||
static rtx
|
||
move_insn (insn, last)
|
||
rtx insn, last;
|
||
{
|
||
rtx retval = NULL;
|
||
|
||
/* If INSN has SCHED_GROUP_P set, then issue it and any other
|
||
insns with SCHED_GROUP_P set first. */
|
||
while (SCHED_GROUP_P (insn))
|
||
{
|
||
rtx prev = PREV_INSN (insn);
|
||
|
||
/* Move a SCHED_GROUP_P insn. */
|
||
move_insn1 (insn, last);
|
||
/* If this is the first call to reemit_notes, then record
|
||
its return value. */
|
||
if (retval == NULL_RTX)
|
||
retval = reemit_notes (insn, insn);
|
||
else
|
||
reemit_notes (insn, insn);
|
||
insn = prev;
|
||
}
|
||
|
||
/* Now move the first non SCHED_GROUP_P insn. */
|
||
move_insn1 (insn, last);
|
||
|
||
/* If this is the first call to reemit_notes, then record
|
||
its return value. */
|
||
if (retval == NULL_RTX)
|
||
retval = reemit_notes (insn, insn);
|
||
else
|
||
reemit_notes (insn, insn);
|
||
|
||
return retval;
|
||
}
|
||
|
||
/* Called from backends from targetm.sched.reorder to emit stuff into
|
||
the instruction stream. */
|
||
|
||
rtx
|
||
sched_emit_insn (pat)
|
||
rtx pat;
|
||
{
|
||
rtx insn = emit_insn_after (pat, last_scheduled_insn);
|
||
last_scheduled_insn = insn;
|
||
return insn;
|
||
}
|
||
|
||
/* Use forward list scheduling to rearrange insns of block B in region RGN,
|
||
possibly bringing insns from subsequent blocks in the same region. */
|
||
|
||
void
|
||
schedule_block (b, rgn_n_insns)
|
||
int b;
|
||
int rgn_n_insns;
|
||
{
|
||
struct ready_list ready;
|
||
int can_issue_more;
|
||
|
||
/* Head/tail info for this block. */
|
||
rtx prev_head = current_sched_info->prev_head;
|
||
rtx next_tail = current_sched_info->next_tail;
|
||
rtx head = NEXT_INSN (prev_head);
|
||
rtx tail = PREV_INSN (next_tail);
|
||
|
||
/* We used to have code to avoid getting parameters moved from hard
|
||
argument registers into pseudos.
|
||
|
||
However, it was removed when it proved to be of marginal benefit
|
||
and caused problems because schedule_block and compute_forward_dependences
|
||
had different notions of what the "head" insn was. */
|
||
|
||
if (head == tail && (! INSN_P (head)))
|
||
abort ();
|
||
|
||
/* Debug info. */
|
||
if (sched_verbose)
|
||
{
|
||
fprintf (sched_dump, ";; ======================================================\n");
|
||
fprintf (sched_dump,
|
||
";; -- basic block %d from %d to %d -- %s reload\n",
|
||
b, INSN_UID (head), INSN_UID (tail),
|
||
(reload_completed ? "after" : "before"));
|
||
fprintf (sched_dump, ";; ======================================================\n");
|
||
fprintf (sched_dump, "\n");
|
||
|
||
visualize_alloc ();
|
||
init_block_visualization ();
|
||
}
|
||
|
||
clear_units ();
|
||
|
||
/* Allocate the ready list. */
|
||
ready.veclen = rgn_n_insns + 1 + issue_rate;
|
||
ready.first = ready.veclen - 1;
|
||
ready.vec = (rtx *) xmalloc (ready.veclen * sizeof (rtx));
|
||
ready.n_ready = 0;
|
||
|
||
(*current_sched_info->init_ready_list) (&ready);
|
||
|
||
if (targetm.sched.md_init)
|
||
(*targetm.sched.md_init) (sched_dump, sched_verbose, ready.veclen);
|
||
|
||
/* We start inserting insns after PREV_HEAD. */
|
||
last_scheduled_insn = prev_head;
|
||
|
||
/* Initialize INSN_QUEUE. Q_SIZE is the total number of insns in the
|
||
queue. */
|
||
q_ptr = 0;
|
||
q_size = 0;
|
||
last_clock_var = 0;
|
||
memset ((char *) insn_queue, 0, sizeof (insn_queue));
|
||
|
||
/* Start just before the beginning of time. */
|
||
clock_var = -1;
|
||
|
||
/* Loop until all the insns in BB are scheduled. */
|
||
while ((*current_sched_info->schedule_more_p) ())
|
||
{
|
||
clock_var++;
|
||
|
||
/* Add to the ready list all pending insns that can be issued now.
|
||
If there are no ready insns, increment clock until one
|
||
is ready and add all pending insns at that point to the ready
|
||
list. */
|
||
queue_to_ready (&ready);
|
||
|
||
if (ready.n_ready == 0)
|
||
abort ();
|
||
|
||
if (sched_verbose >= 2)
|
||
{
|
||
fprintf (sched_dump, ";;\t\tReady list after queue_to_ready: ");
|
||
debug_ready_list (&ready);
|
||
}
|
||
|
||
/* Sort the ready list based on priority. */
|
||
ready_sort (&ready);
|
||
|
||
/* Allow the target to reorder the list, typically for
|
||
better instruction bundling. */
|
||
if (targetm.sched.reorder)
|
||
can_issue_more =
|
||
(*targetm.sched.reorder) (sched_dump, sched_verbose,
|
||
ready_lastpos (&ready),
|
||
&ready.n_ready, clock_var);
|
||
else
|
||
can_issue_more = issue_rate;
|
||
|
||
if (sched_verbose && targetm.sched.cycle_display)
|
||
last_scheduled_insn
|
||
= (*targetm.sched.cycle_display) (clock_var, last_scheduled_insn);
|
||
|
||
if (sched_verbose)
|
||
{
|
||
fprintf (sched_dump, "\n;;\tReady list (t =%3d): ", clock_var);
|
||
debug_ready_list (&ready);
|
||
}
|
||
|
||
/* Issue insns from ready list. */
|
||
while (ready.n_ready != 0
|
||
&& can_issue_more
|
||
&& (*current_sched_info->schedule_more_p) ())
|
||
{
|
||
/* Select and remove the insn from the ready list. */
|
||
rtx insn = ready_remove_first (&ready);
|
||
int cost = actual_hazard (insn_unit (insn), insn, clock_var, 0);
|
||
|
||
if (cost >= 1)
|
||
{
|
||
queue_insn (insn, cost);
|
||
continue;
|
||
}
|
||
|
||
if (! (*current_sched_info->can_schedule_ready_p) (insn))
|
||
goto next;
|
||
|
||
last_scheduled_insn = move_insn (insn, last_scheduled_insn);
|
||
|
||
if (targetm.sched.variable_issue)
|
||
can_issue_more =
|
||
(*targetm.sched.variable_issue) (sched_dump, sched_verbose,
|
||
insn, can_issue_more);
|
||
else
|
||
can_issue_more--;
|
||
|
||
schedule_insn (insn, &ready, clock_var);
|
||
|
||
next:
|
||
if (targetm.sched.reorder2)
|
||
{
|
||
/* Sort the ready list based on priority. */
|
||
if (ready.n_ready > 0)
|
||
ready_sort (&ready);
|
||
can_issue_more =
|
||
(*targetm.sched.reorder2) (sched_dump,sched_verbose,
|
||
ready.n_ready
|
||
? ready_lastpos (&ready) : NULL,
|
||
&ready.n_ready, clock_var);
|
||
}
|
||
}
|
||
|
||
/* Debug info. */
|
||
if (sched_verbose)
|
||
visualize_scheduled_insns (clock_var);
|
||
}
|
||
|
||
if (targetm.sched.md_finish)
|
||
(*targetm.sched.md_finish) (sched_dump, sched_verbose);
|
||
|
||
/* Debug info. */
|
||
if (sched_verbose)
|
||
{
|
||
fprintf (sched_dump, ";;\tReady list (final): ");
|
||
debug_ready_list (&ready);
|
||
print_block_visualization ("");
|
||
}
|
||
|
||
/* Sanity check -- queue must be empty now. Meaningless if region has
|
||
multiple bbs. */
|
||
if (current_sched_info->queue_must_finish_empty && q_size != 0)
|
||
abort ();
|
||
|
||
/* Update head/tail boundaries. */
|
||
head = NEXT_INSN (prev_head);
|
||
tail = last_scheduled_insn;
|
||
|
||
/* Restore-other-notes: NOTE_LIST is the end of a chain of notes
|
||
previously found among the insns. Insert them at the beginning
|
||
of the insns. */
|
||
if (note_list != 0)
|
||
{
|
||
rtx note_head = note_list;
|
||
|
||
while (PREV_INSN (note_head))
|
||
{
|
||
note_head = PREV_INSN (note_head);
|
||
}
|
||
|
||
PREV_INSN (note_head) = PREV_INSN (head);
|
||
NEXT_INSN (PREV_INSN (head)) = note_head;
|
||
PREV_INSN (head) = note_list;
|
||
NEXT_INSN (note_list) = head;
|
||
head = note_head;
|
||
}
|
||
|
||
/* Debugging. */
|
||
if (sched_verbose)
|
||
{
|
||
fprintf (sched_dump, ";; total time = %d\n;; new head = %d\n",
|
||
clock_var, INSN_UID (head));
|
||
fprintf (sched_dump, ";; new tail = %d\n\n",
|
||
INSN_UID (tail));
|
||
visualize_free ();
|
||
}
|
||
|
||
current_sched_info->head = head;
|
||
current_sched_info->tail = tail;
|
||
|
||
free (ready.vec);
|
||
}
|
||
|
||
/* Set_priorities: compute priority of each insn in the block. */
|
||
|
||
int
|
||
set_priorities (head, tail)
|
||
rtx head, tail;
|
||
{
|
||
rtx insn;
|
||
int n_insn;
|
||
|
||
rtx prev_head;
|
||
|
||
prev_head = PREV_INSN (head);
|
||
|
||
if (head == tail && (! INSN_P (head)))
|
||
return 0;
|
||
|
||
n_insn = 0;
|
||
for (insn = tail; insn != prev_head; insn = PREV_INSN (insn))
|
||
{
|
||
if (GET_CODE (insn) == NOTE)
|
||
continue;
|
||
|
||
if (!(SCHED_GROUP_P (insn)))
|
||
n_insn++;
|
||
(void) priority (insn);
|
||
}
|
||
|
||
return n_insn;
|
||
}
|
||
|
||
/* Initialize some global state for the scheduler. DUMP_FILE is to be used
|
||
for debugging output. */
|
||
|
||
void
|
||
sched_init (dump_file)
|
||
FILE *dump_file;
|
||
{
|
||
int luid, b;
|
||
rtx insn;
|
||
|
||
/* Disable speculative loads in their presence if cc0 defined. */
|
||
#ifdef HAVE_cc0
|
||
flag_schedule_speculative_load = 0;
|
||
#endif
|
||
|
||
/* Set dump and sched_verbose for the desired debugging output. If no
|
||
dump-file was specified, but -fsched-verbose=N (any N), print to stderr.
|
||
For -fsched-verbose=N, N>=10, print everything to stderr. */
|
||
sched_verbose = sched_verbose_param;
|
||
if (sched_verbose_param == 0 && dump_file)
|
||
sched_verbose = 1;
|
||
sched_dump = ((sched_verbose_param >= 10 || !dump_file)
|
||
? stderr : dump_file);
|
||
|
||
/* Initialize issue_rate. */
|
||
if (targetm.sched.issue_rate)
|
||
issue_rate = (*targetm.sched.issue_rate) ();
|
||
else
|
||
issue_rate = 1;
|
||
|
||
/* We use LUID 0 for the fake insn (UID 0) which holds dependencies for
|
||
pseudos which do not cross calls. */
|
||
old_max_uid = get_max_uid () + 1;
|
||
|
||
h_i_d = (struct haifa_insn_data *) xcalloc (old_max_uid, sizeof (*h_i_d));
|
||
|
||
h_i_d[0].luid = 0;
|
||
luid = 1;
|
||
for (b = 0; b < n_basic_blocks; b++)
|
||
for (insn = BLOCK_HEAD (b);; insn = NEXT_INSN (insn))
|
||
{
|
||
INSN_LUID (insn) = luid;
|
||
|
||
/* Increment the next luid, unless this is a note. We don't
|
||
really need separate IDs for notes and we don't want to
|
||
schedule differently depending on whether or not there are
|
||
line-number notes, i.e., depending on whether or not we're
|
||
generating debugging information. */
|
||
if (GET_CODE (insn) != NOTE)
|
||
++luid;
|
||
|
||
if (insn == BLOCK_END (b))
|
||
break;
|
||
}
|
||
|
||
init_dependency_caches (luid);
|
||
|
||
compute_bb_for_insn (old_max_uid);
|
||
|
||
init_alias_analysis ();
|
||
|
||
if (write_symbols != NO_DEBUG)
|
||
{
|
||
rtx line;
|
||
|
||
line_note_head = (rtx *) xcalloc (n_basic_blocks, sizeof (rtx));
|
||
|
||
/* Save-line-note-head:
|
||
Determine the line-number at the start of each basic block.
|
||
This must be computed and saved now, because after a basic block's
|
||
predecessor has been scheduled, it is impossible to accurately
|
||
determine the correct line number for the first insn of the block. */
|
||
|
||
for (b = 0; b < n_basic_blocks; b++)
|
||
{
|
||
for (line = BLOCK_HEAD (b); line; line = PREV_INSN (line))
|
||
if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0)
|
||
{
|
||
line_note_head[b] = line;
|
||
break;
|
||
}
|
||
/* Do a forward search as well, since we won't get to see the first
|
||
notes in a basic block. */
|
||
for (line = BLOCK_HEAD (b); line; line = NEXT_INSN (line))
|
||
{
|
||
if (INSN_P (line))
|
||
break;
|
||
if (GET_CODE (line) == NOTE && NOTE_LINE_NUMBER (line) > 0)
|
||
line_note_head[b] = line;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Find units used in this function, for visualization. */
|
||
if (sched_verbose)
|
||
init_target_units ();
|
||
|
||
/* ??? Add a NOTE after the last insn of the last basic block. It is not
|
||
known why this is done. */
|
||
|
||
insn = BLOCK_END (n_basic_blocks - 1);
|
||
if (NEXT_INSN (insn) == 0
|
||
|| (GET_CODE (insn) != NOTE
|
||
&& GET_CODE (insn) != CODE_LABEL
|
||
/* Don't emit a NOTE if it would end up before a BARRIER. */
|
||
&& GET_CODE (NEXT_INSN (insn)) != BARRIER))
|
||
{
|
||
emit_note_after (NOTE_INSN_DELETED, BLOCK_END (n_basic_blocks - 1));
|
||
/* Make insn to appear outside BB. */
|
||
BLOCK_END (n_basic_blocks - 1) = PREV_INSN (BLOCK_END (n_basic_blocks - 1));
|
||
}
|
||
|
||
/* Compute INSN_REG_WEIGHT for all blocks. We must do this before
|
||
removing death notes. */
|
||
for (b = n_basic_blocks - 1; b >= 0; b--)
|
||
find_insn_reg_weight (b);
|
||
}
|
||
|
||
/* Free global data used during insn scheduling. */
|
||
|
||
void
|
||
sched_finish ()
|
||
{
|
||
free (h_i_d);
|
||
free_dependency_caches ();
|
||
end_alias_analysis ();
|
||
if (write_symbols != NO_DEBUG)
|
||
free (line_note_head);
|
||
}
|
||
#endif /* INSN_SCHEDULING */
|