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gnu / gcc / cd99b30c7cf1e68ef76ed2af7a41ac74c78116fe / . / gcc / haifa-sched.c
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/* Instruction scheduling pass.
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Free Software Foundation, Inc.
Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by,
and currently maintained by, Jim Wilson (wilson@cygnus.com)
This file is part of GCC.
GCC 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 3, or (at your option) any later
version.
GCC 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 GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* Instruction scheduling pass. This file, along with sched-deps.c,
contains the generic parts. The actual entry point is found for
the normal instruction scheduling pass is found in sched-rgn.c.
We compute insn priorities based on data dependencies. Flow
analysis only creates a fraction of the data-dependencies we must
observe: namely, only those dependencies which the combiner can be
expected to use. For this pass, we must therefore create the
remaining dependencies we need to observe: register dependencies,
memory dependencies, dependencies to keep function calls in order,
and the dependence between a conditional branch and the setting of
condition codes are all dealt with here.
The scheduler first traverses the data flow graph, starting with
the last instruction, and proceeding to the first, assigning values
to insn_priority as it goes. This sorts the instructions
topologically by data dependence.
Once priorities have been established, we order the insns using
list scheduling. This works as follows: starting with a list of
all the ready insns, and sorted according to priority number, we
schedule the insn from the end of the list by placing its
predecessors in the list according to their priority order. We
consider this insn scheduled by setting the pointer to the "end" of
the list to point to the previous insn. When an insn has no
predecessors, we either queue it until sufficient time has elapsed
or add it to the ready list. As the instructions are scheduled or
when stalls are introduced, the queue advances and dumps insns into
the ready list. When all insns down to the lowest priority have
been scheduled, the critical path of the basic block has been made
as short as possible. The remaining insns are then scheduled in
remaining slots.
The following list shows the order in which we want to break ties
among insns in the ready list:
1. choose insn with the longest path to end of bb, ties
broken by
2. choose insn with least contribution to register pressure,
ties broken by
3. prefer in-block upon interblock motion, ties broken by
4. prefer useful upon speculative motion, ties broken by
5. choose insn with largest control flow probability, ties
broken by
6. choose insn with the least dependences upon the previously
scheduled insn, or finally
7 choose the insn which has the most insns dependent on it.
8. choose insn with lowest UID.
Memory references complicate matters. Only if we can be certain
that memory references are not part of the data dependency graph
(via true, anti, or output dependence), can we move operations past
memory references. To first approximation, reads can be done
independently, while writes introduce dependencies. Better
approximations will yield fewer dependencies.
Before reload, an extended analysis of interblock data dependences
is required for interblock scheduling. This is performed in
compute_block_backward_dependences ().
Dependencies set up by memory references are treated in exactly the
same way as other dependencies, by using insn backward dependences
INSN_BACK_DEPS. INSN_BACK_DEPS are translated into forward dependences
INSN_FORW_DEPS the purpose of forward list scheduling.
Having optimized the critical path, we may have also unduly
extended the lifetimes of some registers. If an operation requires
that constants be loaded into registers, it is certainly desirable
to load those constants as early as necessary, but no earlier.
I.e., it will not do to load up a bunch of registers at the
beginning of a basic block only to use them at the end, if they
could be loaded later, since this may result in excessive register
utilization.
Note that since branches are never in basic blocks, but only end
basic blocks, this pass will not move branches. But that is ok,
since we can use GNU's delayed branch scheduling pass to take care
of this case.
Also note that no further optimizations based on algebraic
identities are performed, so this pass would be a good one to
perform instruction splitting, such as breaking up a multiply
instruction into shifts and adds where that is profitable.
Given the memory aliasing analysis that this pass should perform,
it should be possible to remove redundant stores to memory, and to
load values from registers instead of hitting memory.
Before reload, speculative insns are moved only if a 'proof' exists
that no exception will be caused by this, and if no live registers
exist that inhibit the motion (live registers constraints are not
represented by data dependence edges).
This pass must update information that subsequent passes expect to
be correct. Namely: reg_n_refs, reg_n_sets, reg_n_deaths,
reg_n_calls_crossed, and reg_live_length. Also, BB_HEAD, BB_END.
The information in the line number notes is carefully retained by
this pass. Notes that refer to the starting and ending of
exception regions are also carefully retained by this pass. All
other NOTE insns are grouped in their same relative order at the
beginning of basic blocks and regions that have been scheduled. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "toplev.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "regs.h"
#include "function.h"
#include "flags.h"
#include "insn-config.h"
#include "insn-attr.h"
#include "except.h"
#include "toplev.h"
#include "recog.h"
#include "sched-int.h"
#include "target.h"
#include "output.h"
#include "params.h"
#include "vecprim.h"
#include "dbgcnt.h"
#include "cfgloop.h"
#ifdef INSN_SCHEDULING
/* issue_rate is the number of insns that can be scheduled in the same
machine cycle. It can be defined in the config/mach/mach.h file,
otherwise we set it to 1. */
int issue_rate;
/* sched-verbose controls the amount of debugging output the
scheduler prints. It is controlled by -fsched-verbose=N:
N>0 and no -DSR : the output is directed to stderr.
N>=10 will direct the printouts to stderr (regardless of -dSR).
N=1: same as -dSR.
N=2: bb's probabilities, detailed ready list info, unit/insn info.
N=3: rtl at abort point, control-flow, regions info.
N=5: dependences info. */
static int sched_verbose_param = 0;
int sched_verbose = 0;
/* Debugging file. All printouts are sent to dump, which is always set,
either to stderr, or to the dump listing file (-dRS). */
FILE *sched_dump = 0;
/* fix_sched_param() is called from toplev.c upon detection
of the -fsched-verbose=N option. */
void
fix_sched_param (const char *param, const char *val)
{
if (!strcmp (param, "verbose"))
sched_verbose_param = atoi (val);
else
warning (0, "fix_sched_param: unknown param: %s", param);
}
/* This is a placeholder for the scheduler parameters common
to all schedulers. */
struct common_sched_info_def *common_sched_info;
#define INSN_TICK(INSN) (HID (INSN)->tick)
#define INTER_TICK(INSN) (HID (INSN)->inter_tick)
/* If INSN_TICK of an instruction is equal to INVALID_TICK,
then it should be recalculated from scratch. */
#define INVALID_TICK (-(max_insn_queue_index + 1))
/* The minimal value of the INSN_TICK of an instruction. */
#define MIN_TICK (-max_insn_queue_index)
/* Issue points are used to distinguish between instructions in max_issue ().
For now, all instructions are equally good. */
#define ISSUE_POINTS(INSN) 1
/* List of important notes we must keep around. This is a pointer to the
last element in the list. */
rtx note_list;
static struct spec_info_def spec_info_var;
/* Description of the speculative part of the scheduling.
If NULL - no speculation. */
spec_info_t spec_info = NULL;
/* True, if recovery block was added during scheduling of current block.
Used to determine, if we need to fix INSN_TICKs. */
static bool haifa_recovery_bb_recently_added_p;
/* True, if recovery block was added during this scheduling pass.
Used to determine if we should have empty memory pools of dependencies
after finishing current region. */
bool haifa_recovery_bb_ever_added_p;
/* Counters of different types of speculative instructions. */
static int nr_begin_data, nr_be_in_data, nr_begin_control, nr_be_in_control;
/* Array used in {unlink, restore}_bb_notes. */
static rtx *bb_header = 0;
/* Basic block after which recovery blocks will be created. */
static basic_block before_recovery;
/* Basic block just before the EXIT_BLOCK and after recovery, if we have
created it. */
basic_block after_recovery;
/* FALSE if we add bb to another region, so we don't need to initialize it. */
bool adding_bb_to_current_region_p = true;
/* Queues, etc. */
/* An instruction is ready to be scheduled when all insns preceding it
have already been scheduled. It is important to ensure that all
insns which use its result will not be executed until its result
has been computed. An insn is maintained in one of four structures:
(P) the "Pending" set of insns which cannot be scheduled until
their dependencies have been satisfied.
(Q) the "Queued" set of insns that can be scheduled when sufficient
time has passed.
(R) the "Ready" list of unscheduled, uncommitted insns.
(S) the "Scheduled" list of insns.
Initially, all insns are either "Pending" or "Ready" depending on
whether their dependencies are satisfied.
Insns move from the "Ready" list to the "Scheduled" list as they
are committed to the schedule. As this occurs, the insns in the
"Pending" list have their dependencies satisfied and move to either
the "Ready" list or the "Queued" set depending on whether
sufficient time has passed to make them ready. As time passes,
insns move from the "Queued" set to the "Ready" list.
The "Pending" list (P) are the insns in the INSN_FORW_DEPS of the
unscheduled insns, i.e., those that are ready, queued, and pending.
The "Queued" set (Q) is implemented by the variable `insn_queue'.
The "Ready" list (R) is implemented by the variables `ready' and
`n_ready'.
The "Scheduled" list (S) is the new insn chain built by this pass.
The transition (R->S) is implemented in the scheduling loop in
`schedule_block' when the best insn to schedule is chosen.
The transitions (P->R and P->Q) are implemented in `schedule_insn' as
insns move from the ready list to the scheduled list.
The transition (Q->R) is implemented in 'queue_to_insn' as time
passes or stalls are introduced. */
/* Implement a circular buffer to delay instructions until sufficient
time has passed. For the new pipeline description interface,
MAX_INSN_QUEUE_INDEX is a power of two minus one which is not less
than maximal time of instruction execution computed by genattr.c on
the base maximal time of functional unit reservations and getting a
result. This is the longest time an insn may be queued. */
static rtx *insn_queue;
static int q_ptr = 0;
static int q_size = 0;
#define NEXT_Q(X) (((X)+1) & max_insn_queue_index)
#define NEXT_Q_AFTER(X, C) (((X)+C) & max_insn_queue_index)
#define QUEUE_SCHEDULED (-3)
#define QUEUE_NOWHERE (-2)
#define QUEUE_READY (-1)
/* QUEUE_SCHEDULED - INSN is scheduled.
QUEUE_NOWHERE - INSN isn't scheduled yet and is neither in
queue or ready list.
QUEUE_READY - INSN is in ready list.
N >= 0 - INSN queued for X [where NEXT_Q_AFTER (q_ptr, X) == N] cycles. */
#define QUEUE_INDEX(INSN) (HID (INSN)->queue_index)
/* The following variable value refers for all current and future
reservations of the processor units. */
state_t curr_state;
/* The following variable value is size of memory representing all
current and future reservations of the processor units. */
size_t dfa_state_size;
/* The following array is used to find the best insn from ready when
the automaton pipeline interface is used. */
char *ready_try = NULL;
/* The ready list. */
struct ready_list ready = {NULL, 0, 0, 0};
/* The pointer to the ready list (to be removed). */
static struct ready_list *readyp = &ready;
/* Scheduling clock. */
static int clock_var;
static int may_trap_exp (const_rtx, int);
/* Nonzero iff the address is comprised from at most 1 register. */
#define CONST_BASED_ADDRESS_P(x) \
(REG_P (x) \
|| ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS \
|| (GET_CODE (x) == LO_SUM)) \
&& (CONSTANT_P (XEXP (x, 0)) \
|| CONSTANT_P (XEXP (x, 1)))))
/* Returns a class that insn with GET_DEST(insn)=x may belong to,
as found by analyzing insn's expression. */
static int haifa_luid_for_non_insn (rtx x);
/* Haifa version of sched_info hooks common to all headers. */
const struct common_sched_info_def haifa_common_sched_info =
{
NULL, /* fix_recovery_cfg */
NULL, /* add_block */
NULL, /* estimate_number_of_insns */
haifa_luid_for_non_insn, /* luid_for_non_insn */
SCHED_PASS_UNKNOWN /* sched_pass_id */
};
const struct sched_scan_info_def *sched_scan_info;
/* Mapping from instruction UID to its Logical UID. */
VEC (int, heap) *sched_luids = NULL;
/* Next LUID to assign to an instruction. */
int sched_max_luid = 1;
/* Haifa Instruction Data. */
VEC (haifa_insn_data_def, heap) *h_i_d = NULL;
void (* sched_init_only_bb) (basic_block, basic_block);
/* Split block function. Different schedulers might use different functions
to handle their internal data consistent. */
basic_block (* sched_split_block) (basic_block, rtx);
/* Create empty basic block after the specified block. */
basic_block (* sched_create_empty_bb) (basic_block);
static int
may_trap_exp (const_rtx x, int is_store)
{
enum rtx_code code;
if (x == 0)
return TRAP_FREE;
code = GET_CODE (x);
if (is_store)
{
if (code == MEM && may_trap_p (x))
return TRAP_RISKY;
else
return TRAP_FREE;
}
if (code == MEM)
{
/* The insn uses memory: a volatile load. */
if (MEM_VOLATILE_P (x))
return IRISKY;
/* An exception-free load. */
if (!may_trap_p (x))
return IFREE;
/* A load with 1 base register, to be further checked. */
if (CONST_BASED_ADDRESS_P (XEXP (x, 0)))
return PFREE_CANDIDATE;
/* No info on the load, to be further checked. */
return PRISKY_CANDIDATE;
}
else
{
const char *fmt;
int i, insn_class = TRAP_FREE;
/* Neither store nor load, check if it may cause a trap. */
if (may_trap_p (x))
return TRAP_RISKY;
/* Recursive step: walk the insn... */
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
if (fmt[i] == 'e')
{
int tmp_class = may_trap_exp (XEXP (x, i), is_store);
insn_class = WORST_CLASS (insn_class, tmp_class);
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
{
int tmp_class = may_trap_exp (XVECEXP (x, i, j), is_store);
insn_class = WORST_CLASS (insn_class, tmp_class);
if (insn_class == TRAP_RISKY || insn_class == IRISKY)
break;
}
}
if (insn_class == TRAP_RISKY || insn_class == IRISKY)
break;
}
return insn_class;
}
}
/* Classifies rtx X of an insn for the purpose of verifying that X can be
executed speculatively (and consequently the insn can be moved
speculatively), by examining X, returning:
TRAP_RISKY: store, or risky non-load insn (e.g. division by variable).
TRAP_FREE: non-load insn.
IFREE: load from a globally safe location.
IRISKY: volatile load.
PFREE_CANDIDATE, PRISKY_CANDIDATE: load that need to be checked for
being either PFREE or PRISKY. */
static int
haifa_classify_rtx (const_rtx x)
{
int tmp_class = TRAP_FREE;
int insn_class = TRAP_FREE;
enum rtx_code code;
if (GET_CODE (x) == PARALLEL)
{
int i, len = XVECLEN (x, 0);
for (i = len - 1; i >= 0; i--)
{
tmp_class = haifa_classify_rtx (XVECEXP (x, 0, i));
insn_class = WORST_CLASS (insn_class, tmp_class);
if (insn_class == TRAP_RISKY || insn_class == IRISKY)
break;
}
}
else
{
code = GET_CODE (x);
switch (code)
{
case CLOBBER:
/* Test if it is a 'store'. */
tmp_class = may_trap_exp (XEXP (x, 0), 1);
break;
case SET:
/* Test if it is a store. */
tmp_class = may_trap_exp (SET_DEST (x), 1);
if (tmp_class == TRAP_RISKY)
break;
/* Test if it is a load. */
tmp_class =
WORST_CLASS (tmp_class,
may_trap_exp (SET_SRC (x), 0));
break;
case COND_EXEC:
tmp_class = haifa_classify_rtx (COND_EXEC_CODE (x));
if (tmp_class == TRAP_RISKY)
break;
tmp_class = WORST_CLASS (tmp_class,
may_trap_exp (COND_EXEC_TEST (x), 0));
break;
case TRAP_IF:
tmp_class = TRAP_RISKY;
break;
default:;
}
insn_class = tmp_class;
}
return insn_class;
}
int
haifa_classify_insn (const_rtx insn)
{
return haifa_classify_rtx (PATTERN (insn));
}
/* Forward declarations. */
static int priority (rtx);
static int rank_for_schedule (const void *, const void *);
static void swap_sort (rtx *, int);
static void queue_insn (rtx, int);
static int schedule_insn (rtx);
static int find_set_reg_weight (const_rtx);
static void find_insn_reg_weight (const_rtx);
static void adjust_priority (rtx);
static void advance_one_cycle (void);
static void extend_h_i_d (void);
/* Notes handling mechanism:
=========================
Generally, NOTES are saved before scheduling and restored after scheduling.
The scheduler distinguishes between two types of notes:
(1) LOOP_BEGIN, LOOP_END, SETJMP, EHREGION_BEG, EHREGION_END notes:
Before scheduling a region, a pointer to the note is added to the insn
that follows or precedes it. (This happens as part of the data dependence
computation). After scheduling an insn, the pointer contained in it is
used for regenerating the corresponding note (in reemit_notes).
(2) All other notes (e.g. INSN_DELETED): Before scheduling a block,
these notes are put in a list (in rm_other_notes() and
unlink_other_notes ()). After scheduling the block, these notes are
inserted at the beginning of the block (in schedule_block()). */
static void ready_add (struct ready_list *, rtx, bool);
static rtx ready_remove_first (struct ready_list *);
static void queue_to_ready (struct ready_list *);
static int early_queue_to_ready (state_t, struct ready_list *);
static void debug_ready_list (struct ready_list *);
/* The following functions are used to implement multi-pass scheduling
on the first cycle. */
static rtx ready_remove (struct ready_list *, int);
static void ready_remove_insn (rtx);
static int choose_ready (struct ready_list *, rtx *);
static void fix_inter_tick (rtx, rtx);
static int fix_tick_ready (rtx);
static void change_queue_index (rtx, int);
/* The following functions are used to implement scheduling of data/control
speculative instructions. */
static void extend_h_i_d (void);
static void init_h_i_d (rtx);
static void generate_recovery_code (rtx);
static void process_insn_forw_deps_be_in_spec (rtx, rtx, ds_t);
static void begin_speculative_block (rtx);
static void add_to_speculative_block (rtx);
static void init_before_recovery (basic_block *);
static void create_check_block_twin (rtx, bool);
static void fix_recovery_deps (basic_block);
static void haifa_change_pattern (rtx, rtx);
static void dump_new_block_header (int, basic_block, rtx, rtx);
static void restore_bb_notes (basic_block);
static void fix_jump_move (rtx);
static void move_block_after_check (rtx);
static void move_succs (VEC(edge,gc) **, basic_block);
static void sched_remove_insn (rtx);
static void clear_priorities (rtx, rtx_vec_t *);
static void calc_priorities (rtx_vec_t);
static void add_jump_dependencies (rtx, rtx);
#ifdef ENABLE_CHECKING
static int has_edge_p (VEC(edge,gc) *, int);
static void check_cfg (rtx, rtx);
#endif
#endif /* INSN_SCHEDULING */
/* Point to state used for the current scheduling pass. */
struct haifa_sched_info *current_sched_info;
#ifndef INSN_SCHEDULING
void
schedule_insns (void)
{
}
#else
/* Pointer to the last instruction scheduled. Used by rank_for_schedule,
so that insns independent of the last scheduled insn will be preferred
over dependent instructions. */
static rtx last_scheduled_insn;
/* Cached cost of the instruction. Use below function to get cost of the
insn. -1 here means that the field is not initialized. */
#define INSN_COST(INSN) (HID (INSN)->cost)
/* Compute cost of executing INSN.
This is the number of cycles between instruction issue and
instruction results. */
HAIFA_INLINE int
insn_cost (rtx insn)
{
int cost;
if (sel_sched_p ())
{
if (recog_memoized (insn) < 0)
return 0;
cost = insn_default_latency (insn);
if (cost < 0)
cost = 0;
return cost;
}
cost = INSN_COST (insn);
if (cost < 0)
{
/* A USE insn, or something else we don't need to
understand. We can't pass these directly to
result_ready_cost or insn_default_latency because it will
trigger a fatal error for unrecognizable insns. */
if (recog_memoized (insn) < 0)
{
INSN_COST (insn) = 0;
return 0;
}
else
{
cost = insn_default_latency (insn);
if (cost < 0)
cost = 0;
INSN_COST (insn) = cost;
}
}
return cost;
}
/* Compute cost of dependence LINK.
This is the number of cycles between instruction issue and
instruction results.
??? We also use this function to call recog_memoized on all insns. */
int
dep_cost_1 (dep_t link, dw_t dw)
{
rtx insn = DEP_PRO (link);
rtx used = DEP_CON (link);
int 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. */
if (recog_memoized (used) < 0)
{
cost = 0;
recog_memoized (insn);
}
else
{
enum reg_note dep_type = DEP_TYPE (link);
cost = insn_cost (insn);
if (INSN_CODE (insn) >= 0)
{
if (dep_type == REG_DEP_ANTI)
cost = 0;
else if (dep_type == REG_DEP_OUTPUT)
{
cost = (insn_default_latency (insn)
- insn_default_latency (used));
if (cost <= 0)
cost = 1;
}
else if (bypass_p (insn))
cost = insn_latency (insn, used);
}
if (targetm.sched.adjust_cost_2)
{
cost = targetm.sched.adjust_cost_2 (used, (int) dep_type, insn, cost,
dw);
}
else if (targetm.sched.adjust_cost != NULL)
{
/* This variable is used for backward compatibility with the
targets. */
rtx dep_cost_rtx_link = alloc_INSN_LIST (NULL_RTX, NULL_RTX);
/* Make it self-cycled, so that if some tries to walk over this
incomplete list he/she will be caught in an endless loop. */
XEXP (dep_cost_rtx_link, 1) = dep_cost_rtx_link;
/* Targets use only REG_NOTE_KIND of the link. */
PUT_REG_NOTE_KIND (dep_cost_rtx_link, DEP_TYPE (link));
cost = targetm.sched.adjust_cost (used, dep_cost_rtx_link,
insn, cost);
free_INSN_LIST_node (dep_cost_rtx_link);
}
if (cost < 0)
cost = 0;
}
return cost;
}
/* Compute cost of dependence LINK.
This is the number of cycles between instruction issue and
instruction results. */
int
dep_cost (dep_t link)
{
return dep_cost_1 (link, 0);
}
/* Use this sel-sched.c friendly function in reorder2 instead of increasing
INSN_PRIORITY explicitly. */
void
increase_insn_priority (rtx insn, int amount)
{
if (!sel_sched_p ())
{
/* We're dealing with haifa-sched.c INSN_PRIORITY. */
if (INSN_PRIORITY_KNOWN (insn))
INSN_PRIORITY (insn) += amount;
}
else
{
/* In sel-sched.c INSN_PRIORITY is not kept up to date.
Use EXPR_PRIORITY instead. */
sel_add_to_insn_priority (insn, amount);
}
}
/* Return 'true' if DEP should be included in priority calculations. */
static bool
contributes_to_priority_p (dep_t dep)
{
/* Critical path is meaningful in block boundaries only. */
if (!current_sched_info->contributes_to_priority (DEP_CON (dep),
DEP_PRO (dep)))
return false;
/* If flag COUNT_SPEC_IN_CRITICAL_PATH is set,
then speculative instructions will less likely be
scheduled. That is because the priority of
their producers will increase, and, thus, the
producers will more likely be scheduled, thus,
resolving the dependence. */
if (sched_deps_info->generate_spec_deps
&& !(spec_info->flags & COUNT_SPEC_IN_CRITICAL_PATH)
&& (DEP_STATUS (dep) & SPECULATIVE))
return false;
return true;
}
/* Compute the priority number for INSN. */
static int
priority (rtx insn)
{
if (! INSN_P (insn))
return 0;
/* We should not be interested in priority of an already scheduled insn. */
gcc_assert (QUEUE_INDEX (insn) != QUEUE_SCHEDULED);
if (!INSN_PRIORITY_KNOWN (insn))
{
int this_priority = -1;
if (sd_lists_empty_p (insn, SD_LIST_FORW))
/* ??? We should set INSN_PRIORITY to insn_cost when and insn has
some forward deps but all of them are ignored by
contributes_to_priority hook. At the moment we set priority of
such insn to 0. */
this_priority = insn_cost (insn);
else
{
rtx prev_first, twin;
basic_block rec;
/* For recovery check instructions we calculate priority slightly
different than that of normal instructions. Instead of walking
through INSN_FORW_DEPS (check) list, we walk through
INSN_FORW_DEPS list of each instruction in the corresponding
recovery block. */
/* Selective scheduling does not define RECOVERY_BLOCK macro. */
rec = sel_sched_p () ? NULL : RECOVERY_BLOCK (insn);
if (!rec || rec == EXIT_BLOCK_PTR)
{
prev_first = PREV_INSN (insn);
twin = insn;
}
else
{
prev_first = NEXT_INSN (BB_HEAD (rec));
twin = PREV_INSN (BB_END (rec));
}
do
{
sd_iterator_def sd_it;
dep_t dep;
FOR_EACH_DEP (twin, SD_LIST_FORW, sd_it, dep)
{
rtx next;
int next_priority;
next = DEP_CON (dep);
if (BLOCK_FOR_INSN (next) != rec)
{
int cost;
if (!contributes_to_priority_p (dep))
continue;
if (twin == insn)
cost = dep_cost (dep);
else
{
struct _dep _dep1, *dep1 = &_dep1;
init_dep (dep1, insn, next, REG_DEP_ANTI);
cost = dep_cost (dep1);
}
next_priority = cost + priority (next);
if (next_priority > this_priority)
this_priority = next_priority;
}
}
twin = PREV_INSN (twin);
}
while (twin != prev_first);
}
if (this_priority < 0)
{
gcc_assert (this_priority == -1);
this_priority = insn_cost (insn);
}
INSN_PRIORITY (insn) = this_priority;
INSN_PRIORITY_STATUS (insn) = 1;
}
return INSN_PRIORITY (insn);
}
/* Macros and functions for keeping the priority queue sorted, and
dealing with queuing and dequeuing 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 (const void *x, const void *y)
{
rtx tmp = *(const rtx *) y;
rtx tmp2 = *(const rtx *) x;
int tmp_class, tmp2_class;
int val, priority_val, weight_val, info_val;
/* The insn in a schedule group should be issued the first. */
if (SCHED_GROUP_P (tmp) != SCHED_GROUP_P (tmp2))
return SCHED_GROUP_P (tmp2) ? 1 : -1;
/* Make sure that priority of TMP and TMP2 are initialized. */
gcc_assert (INSN_PRIORITY_KNOWN (tmp) && INSN_PRIORITY_KNOWN (tmp2));
/* Prefer insn with higher priority. */
priority_val = INSN_PRIORITY (tmp2) - INSN_PRIORITY (tmp);
if (priority_val)
return priority_val;
/* Prefer speculative insn with greater dependencies weakness. */
if (spec_info)
{
ds_t ds1, ds2;
dw_t dw1, dw2;
int dw;
ds1 = TODO_SPEC (tmp) & SPECULATIVE;
if (ds1)
dw1 = ds_weak (ds1);
else
dw1 = NO_DEP_WEAK;
ds2 = TODO_SPEC (tmp2) & SPECULATIVE;
if (ds2)
dw2 = ds_weak (ds2);
else
dw2 = NO_DEP_WEAK;
dw = dw2 - dw1;
if (dw > (NO_DEP_WEAK / 8) || dw < -(NO_DEP_WEAK / 8))
return dw;
}
/* 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 (INSN_P (last_scheduled_insn))
{
dep_t dep1;
dep_t dep2;
/* 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. */
dep1 = sd_find_dep_between (last_scheduled_insn, tmp, true);
if (dep1 == NULL || dep_cost (dep1) == 1)
tmp_class = 3;
else if (/* Data dependence. */
DEP_TYPE (dep1) == REG_DEP_TRUE)
tmp_class = 1;
else
tmp_class = 2;
dep2 = sd_find_dep_between (last_scheduled_insn, tmp2, true);
if (dep2 == NULL || dep_cost (dep2) == 1)
tmp2_class = 3;
else if (/* Data dependence. */
DEP_TYPE (dep2) == REG_DEP_TRUE)
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. */
val = (sd_lists_size (tmp2, SD_LIST_FORW)
- sd_lists_size (tmp, SD_LIST_FORW));
if (val != 0)
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 (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 (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]);
gcc_assert (n_cycles <= max_insn_queue_index);
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);
}
QUEUE_INDEX (insn) = next_q;
}
/* Remove INSN from queue. */
static void
queue_remove (rtx insn)
{
gcc_assert (QUEUE_INDEX (insn) >= 0);
remove_free_INSN_LIST_elem (insn, &insn_queue[QUEUE_INDEX (insn)]);
q_size--;
QUEUE_INDEX (insn) = QUEUE_NOWHERE;
}
/* Return a pointer to the bottom of the ready list, i.e. the insn
with the lowest priority. */
rtx *
ready_lastpos (struct ready_list *ready)
{
gcc_assert (ready->n_ready >= 1);
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/highest priority depending on FIRST_P. */
HAIFA_INLINE static void
ready_add (struct ready_list *ready, rtx insn, bool first_p)
{
if (!first_p)
{
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;
}
else
{
if (ready->first == ready->veclen - 1)
{
if (ready->n_ready)
/* ready_lastpos() fails when called with (ready->n_ready == 0). */
memmove (ready->vec + ready->veclen - ready->n_ready - 1,
ready_lastpos (ready),
ready->n_ready * sizeof (rtx));
ready->first = ready->veclen - 2;
}
ready->vec[++(ready->first)] = insn;
}
ready->n_ready++;
gcc_assert (QUEUE_INDEX (insn) != QUEUE_READY);
QUEUE_INDEX (insn) = QUEUE_READY;
}
/* Remove the element with the highest priority from the ready list and
return it. */
HAIFA_INLINE static rtx
ready_remove_first (struct ready_list *ready)
{
rtx t;
gcc_assert (ready->n_ready);
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;
gcc_assert (QUEUE_INDEX (t) == QUEUE_READY);
QUEUE_INDEX (t) = QUEUE_NOWHERE;
return t;
}
/* The following code implements multi-pass scheduling for the first
cycle. In other words, we will try to choose ready insn which
permits to start maximum number of insns on the same cycle. */
/* Return a pointer to the element INDEX from the ready. INDEX for
insn with the highest priority is 0, and the lowest priority has
N_READY - 1. */
rtx
ready_element (struct ready_list *ready, int index)
{
gcc_assert (ready->n_ready && index < ready->n_ready);
return ready->vec[ready->first - index];
}
/* Remove the element INDEX from the ready list and return it. INDEX
for insn with the highest priority is 0, and the lowest priority
has N_READY - 1. */
HAIFA_INLINE static rtx
ready_remove (struct ready_list *ready, int index)
{
rtx t;
int i;
if (index == 0)
return ready_remove_first (ready);
gcc_assert (ready->n_ready && index < ready->n_ready);
t = ready->vec[ready->first - index];
ready->n_ready--;
for (i = index; i < ready->n_ready; i++)
ready->vec[ready->first - i] = ready->vec[ready->first - i - 1];
QUEUE_INDEX (t) = QUEUE_NOWHERE;
return t;
}
/* Remove INSN from the ready list. */
static void
ready_remove_insn (rtx insn)
{
int i;
for (i = 0; i < readyp->n_ready; i++)
if (ready_element (readyp, i) == insn)
{
ready_remove (readyp, i);
return;
}
gcc_unreachable ();
}
/* Sort the ready list READY by ascending priority, using the SCHED_SORT
macro. */
void
ready_sort (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 tweak itself. */
HAIFA_INLINE static void
adjust_priority (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));
}
/* Advance DFA state STATE on one cycle. */
void
advance_state (state_t state)
{
if (targetm.sched.dfa_pre_advance_cycle)
targetm.sched.dfa_pre_advance_cycle ();
if (targetm.sched.dfa_pre_cycle_insn)
state_transition (state,
targetm.sched.dfa_pre_cycle_insn ());
state_transition (state, NULL);
if (targetm.sched.dfa_post_cycle_insn)
state_transition (state,
targetm.sched.dfa_post_cycle_insn ());
if (targetm.sched.dfa_post_advance_cycle)
targetm.sched.dfa_post_advance_cycle ();
}
/* Advance time on one cycle. */
HAIFA_INLINE static void
advance_one_cycle (void)
{
advance_state (curr_state);
if (sched_verbose >= 6)
fprintf (sched_dump, ";;\tAdvanced a state.\n");
}
/* 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. The function
returns necessary cycle advance after issuing the insn (it is not
zero for insns in a schedule group). */
static int
schedule_insn (rtx insn)
{
sd_iterator_def sd_it;
dep_t dep;
int advance = 0;
if (sched_verbose >= 1)
{
char buf[2048];
print_insn (buf, insn, 0);
buf[40] = 0;
fprintf (sched_dump, ";;\t%3i--> %-40s:", clock_var, buf);
if (recog_memoized (insn) < 0)
fprintf (sched_dump, "nothing");
else
print_reservation (sched_dump, insn);
fputc ('\n', sched_dump);
}
/* Scheduling instruction should have all its dependencies resolved and
should have been removed from the ready list. */
gcc_assert (sd_lists_empty_p (insn, SD_LIST_BACK));
gcc_assert (QUEUE_INDEX (insn) == QUEUE_NOWHERE);
QUEUE_INDEX (insn) = QUEUE_SCHEDULED;
gcc_assert (INSN_TICK (insn) >= MIN_TICK);
if (INSN_TICK (insn) > clock_var)
/* INSN has been prematurely moved from the queue to the ready list.
This is possible only if following flag is set. */
gcc_assert (flag_sched_stalled_insns);
/* ??? Probably, if INSN is scheduled prematurely, we should leave
INSN_TICK untouched. This is a machine-dependent issue, actually. */
INSN_TICK (insn) = clock_var;
/* Update dependent instructions. */
for (sd_it = sd_iterator_start (insn, SD_LIST_FORW);
sd_iterator_cond (&sd_it, &dep);)
{
rtx next = DEP_CON (dep);
/* Resolve the dependence between INSN and NEXT.
sd_resolve_dep () moves current dep to another list thus
advancing the iterator. */
sd_resolve_dep (sd_it);
if (!IS_SPECULATION_BRANCHY_CHECK_P (insn))
{
int effective_cost;
effective_cost = try_ready (next);
if (effective_cost >= 0
&& SCHED_GROUP_P (next)
&& advance < effective_cost)
advance = effective_cost;
}
else
/* Check always has only one forward dependence (to the first insn in
the recovery block), therefore, this will be executed only once. */
{
gcc_assert (sd_lists_empty_p (insn, SD_LIST_FORW));
fix_recovery_deps (RECOVERY_BLOCK (insn));
}
}
/* This is the place where scheduler doesn't *basically* need backward and
forward dependencies for INSN anymore. Nevertheless they are used in
heuristics in rank_for_schedule (), early_queue_to_ready () and in
some targets (e.g. rs6000). Thus the earliest place where we *can*
remove dependencies is after targetm.sched.md_finish () call in
schedule_block (). But, on the other side, the safest place to remove
dependencies is when we are finishing scheduling entire region. As we
don't generate [many] dependencies during scheduling itself, we won't
need memory until beginning of next region.
Bottom line: Dependencies are removed for all insns in the end of
scheduling the region. */
/* 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 (issue_rate > 1
&& GET_CODE (PATTERN (insn)) != USE
&& GET_CODE (PATTERN (insn)) != CLOBBER)
{
if (reload_completed)
PUT_MODE (insn, clock_var > last_clock_var ? TImode : VOIDmode);
last_clock_var = clock_var;
}
return advance;
}
/* Functions for handling of notes. */
/* Insert the INSN note at the end of the notes list. */
static void
add_to_note_list (rtx insn, rtx *note_list_end_p)
{
PREV_INSN (insn) = *note_list_end_p;
if (*note_list_end_p)
NEXT_INSN (*note_list_end_p) = insn;
*note_list_end_p = insn;
}
/* Add note list that ends on FROM_END to the end of TO_ENDP. */
void
concat_note_lists (rtx from_end, rtx *to_endp)
{
rtx from_start;
if (from_end == NULL)
/* It's easy when have nothing to concat. */
return;
if (*to_endp == NULL)
/* It's also easy when destination is empty. */
{
*to_endp = from_end;
return;
}
from_start = from_end;
/* A note list should be traversed via PREV_INSN. */
while (PREV_INSN (from_start) != NULL)
from_start = PREV_INSN (from_start);
add_to_note_list (from_start, to_endp);
*to_endp = from_end;
}
/* 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 (rtx insn, rtx tail)
{
rtx prev = PREV_INSN (insn);
while (insn != tail && NOTE_NOT_BB_P (insn))
{
rtx next = NEXT_INSN (insn);
basic_block bb = BLOCK_FOR_INSN (insn);
/* Delete the note from its current position. */
if (prev)
NEXT_INSN (prev) = next;
if (next)
PREV_INSN (next) = prev;
if (bb)
{
/* Basic block can begin with either LABEL or
NOTE_INSN_BASIC_BLOCK. */
gcc_assert (BB_HEAD (bb) != insn);
/* Check if we are removing last insn in the BB. */
if (BB_END (bb) == insn)
BB_END (bb) = prev;
}
/* See sched_analyze to see how these are handled. */
if (NOTE_KIND (insn) != NOTE_INSN_EH_REGION_BEG
&& NOTE_KIND (insn) != NOTE_INSN_EH_REGION_END)
add_to_note_list (insn, &note_list);
insn = next;
}
if (insn == tail)
{
gcc_assert (sel_sched_p ());
return prev;
}
return insn;
}
/* Return the head and tail pointers of ebb starting at BEG and ending
at END. */
void
get_ebb_head_tail (basic_block beg, basic_block end, rtx *headp, rtx *tailp)
{
rtx beg_head = BB_HEAD (beg);
rtx beg_tail = BB_END (beg);
rtx end_head = BB_HEAD (end);
rtx end_tail = BB_END (end);
/* Don't include any notes or labels at the beginning of the BEG
basic block, or notes at the end of the END basic blocks. */
if (LABEL_P (beg_head))
beg_head = NEXT_INSN (beg_head);
while (beg_head != beg_tail)
if (NOTE_P (beg_head))
beg_head = NEXT_INSN (beg_head);
else
break;
*headp = beg_head;
if (beg == end)
end_head = beg_head;
else if (LABEL_P (end_head))
end_head = NEXT_INSN (end_head);
while (end_head != end_tail)
if (NOTE_P (end_tail))
end_tail = PREV_INSN (end_tail);
else
break;
*tailp = end_tail;
}
/* Return nonzero if there are no real insns in the range [ HEAD, TAIL ]. */
int
no_real_insns_p (const_rtx head, const_rtx tail)
{
while (head != NEXT_INSN (tail))
{
if (!NOTE_P (head) && !LABEL_P (head))
return 0;
head = NEXT_INSN (head);
}
return 1;
}
/* Delete notes between HEAD and TAIL and put them in the chain
of notes ended by NOTE_LIST. */
static void
rm_other_notes (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 (NOTE_NOT_BB_P (insn))
{
prev = insn;
insn = unlink_other_notes (insn, next_tail);
gcc_assert ((sel_sched_p ()
|| prev != tail) && prev != head && insn != next_tail);
}
}
}
/* Same as above, but also process REG_SAVE_NOTEs of HEAD. */
void
remove_notes (rtx head, rtx tail)
{
/* rm_other_notes only removes notes which are _inside_ the
block---that is, it won't remove notes before the first real insn
or after the last real insn of the block. So if the first insn
has a REG_SAVE_NOTE which would otherwise be emitted before the
insn, it is redundant with the note before the start of the
block, and so we have to take it out. */
if (INSN_P (head))
{
rtx note;
for (note = REG_NOTES (head); note; note = XEXP (note, 1))
if (REG_NOTE_KIND (note) == REG_SAVE_NOTE)
remove_note (head, note);
}
/* Remove remaining note insns from the block, save them in
note_list. These notes are restored at the end of
schedule_block (). */
rm_other_notes (head, tail);
}
/* Restore-other-notes: NOTE_LIST is the end of a chain of notes
previously found among the insns. Insert them just before HEAD. */
rtx
restore_other_notes (rtx head, basic_block head_bb)
{
if (note_list != 0)
{
rtx note_head = note_list;
if (head)
head_bb = BLOCK_FOR_INSN (head);
else
head = NEXT_INSN (bb_note (head_bb));
while (PREV_INSN (note_head))
{
set_block_for_insn (note_head, head_bb);
note_head = PREV_INSN (note_head);
}
/* In the above cycle we've missed this note. */
set_block_for_insn (note_head, head_bb);
PREV_INSN (note_head) = PREV_INSN (head);
NEXT_INSN (PREV_INSN (head)) = note_head;
PREV_INSN (head) = note_list;
NEXT_INSN (note_list) = head;
if (BLOCK_FOR_INSN (head) != head_bb)
BB_END (head_bb) = note_list;
head = note_head;
}
return head;
}
/* Functions for computation of registers live/usage info. */
/* This function looks for a new register being defined.
If the destination register is already used by the source,
a new register is not needed. */
static int
find_set_reg_weight (const_rtx x)
{
if (GET_CODE (x) == CLOBBER
&& register_operand (SET_DEST (x), VOIDmode))
return 1;
if (GET_CODE (x) == SET
&& register_operand (SET_DEST (x), VOIDmode))
{
if (REG_P (SET_DEST (x)))
{
if (!reg_mentioned_p (SET_DEST (x), SET_SRC (x)))
return 1;
else
return 0;
}
return 1;
}
return 0;
}
/* Calculate INSN_REG_WEIGHT for INSN. */
static void
find_insn_reg_weight (const_rtx insn)
{
int reg_weight = 0;
rtx x;
/* Handle register life information. */
if (! INSN_P (insn))
return;
/* Increment weight for each register born here. */
x = PATTERN (insn);
reg_weight += find_set_reg_weight (x);
if (GET_CODE (x) == PARALLEL)
{
int j;
for (j = XVECLEN (x, 0) - 1; j >= 0; j--)
{
x = XVECEXP (PATTERN (insn), 0, j);
reg_weight += find_set_reg_weight (x);
}
}
/* 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;
}
/* Move insns that became ready to fire from queue to ready list. */
static void
queue_to_ready (struct ready_list *ready)
{
rtx insn;
rtx link;
rtx skip_insn;
q_ptr = NEXT_Q (q_ptr);
if (dbg_cnt (sched_insn) == false)
/* If debug counter is activated do not requeue insn next after
last_scheduled_insn. */
skip_insn = next_nonnote_insn (last_scheduled_insn);
else
skip_insn = NULL_RTX;
/* 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));
/* If the ready list is full, delay the insn for 1 cycle.
See the comment in schedule_block for the rationale. */
if (!reload_completed
&& ready->n_ready > MAX_SCHED_READY_INSNS
&& !SCHED_GROUP_P (insn)
&& insn != skip_insn)
{
if (sched_verbose >= 2)
fprintf (sched_dump, "requeued because ready full\n");
queue_insn (insn, 1);
}
else
{
ready_add (ready, insn, false);
if (sched_verbose >= 2)
fprintf (sched_dump, "moving to ready without stalls\n");
}
}
free_INSN_LIST_list (&insn_queue[q_ptr]);
/* 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 <= max_insn_queue_index; 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, false);
if (sched_verbose >= 2)
fprintf (sched_dump, "moving to ready with %d stalls\n", stalls);
}
free_INSN_LIST_list (&insn_queue[NEXT_Q_AFTER (q_ptr, stalls)]);
advance_one_cycle ();
break;
}
advance_one_cycle ();
}
q_ptr = NEXT_Q_AFTER (q_ptr, stalls);
clock_var += stalls;
}
}
/* Used by early_queue_to_ready. Determines whether it is "ok" to
prematurely move INSN from the queue to the ready list. Currently,
if a target defines the hook 'is_costly_dependence', this function
uses the hook to check whether there exist any dependences which are
considered costly by the target, between INSN and other insns that
have already been scheduled. Dependences are checked up to Y cycles
back, with default Y=1; The flag -fsched-stalled-insns-dep=Y allows
controlling this value.
(Other considerations could be taken into account instead (or in
addition) depending on user flags and target hooks. */
static bool
ok_for_early_queue_removal (rtx insn)
{
int n_cycles;
rtx prev_insn = last_scheduled_insn;
if (targetm.sched.is_costly_dependence)
{
for (n_cycles = flag_sched_stalled_insns_dep; n_cycles; n_cycles--)
{
for ( ; prev_insn; prev_insn = PREV_INSN (prev_insn))
{
int cost;
if (prev_insn == current_sched_info->prev_head)
{
prev_insn = NULL;
break;
}
if (!NOTE_P (prev_insn))
{
dep_t dep;
dep = sd_find_dep_between (prev_insn, insn, true);
if (dep != NULL)
{
cost = dep_cost (dep);
if (targetm.sched.is_costly_dependence (dep, cost,
flag_sched_stalled_insns_dep - n_cycles))
return false;
}
}
if (GET_MODE (prev_insn) == TImode) /* end of dispatch group */
break;
}
if (!prev_insn)
break;
prev_insn = PREV_INSN (prev_insn);
}
}
return true;
}
/* Remove insns from the queue, before they become "ready" with respect
to FU latency considerations. */
static int
early_queue_to_ready (state_t state, struct ready_list *ready)
{
rtx insn;
rtx link;
rtx next_link;
rtx prev_link;
bool move_to_ready;
int cost;
state_t temp_state = alloca (dfa_state_size);
int stalls;
int insns_removed = 0;
/*
Flag '-fsched-stalled-insns=X' determines the aggressiveness of this
function:
X == 0: There is no limit on how many queued insns can be removed
prematurely. (flag_sched_stalled_insns = -1).
X >= 1: Only X queued insns can be removed prematurely in each
invocation. (flag_sched_stalled_insns = X).
Otherwise: Early queue removal is disabled.
(flag_sched_stalled_insns = 0)
*/
if (! flag_sched_stalled_insns)
return 0;
for (stalls = 0; stalls <= max_insn_queue_index; stalls++)
{
if ((link = insn_queue[NEXT_Q_AFTER (q_ptr, stalls)]))
{
if (sched_verbose > 6)
fprintf (sched_dump, ";; look at index %d + %d\n", q_ptr, stalls);
prev_link = 0;
while (link)
{
next_link = XEXP (link, 1);
insn = XEXP (link, 0);
if (insn && sched_verbose > 6)
print_rtl_single (sched_dump, insn);
memcpy (temp_state, state, dfa_state_size);
if (recog_memoized (insn) < 0)
/* non-negative to indicate that it's not ready
to avoid infinite Q->R->Q->R... */
cost = 0;
else
cost = state_transition (temp_state, insn);
if (sched_verbose >= 6)
fprintf (sched_dump, "transition cost = %d\n", cost);
move_to_ready = false;
if (cost < 0)
{
move_to_ready = ok_for_early_queue_removal (insn);
if (move_to_ready == true)
{
/* move from Q to R */
q_size -= 1;
ready_add (ready, insn, false);
if (prev_link)
XEXP (prev_link, 1) = next_link;
else
insn_queue[NEXT_Q_AFTER (q_ptr, stalls)] = next_link;
free_INSN_LIST_node (link);
if (sched_verbose >= 2)
fprintf (sched_dump, ";;\t\tEarly Q-->Ready: insn %s\n",
(*current_sched_info->print_insn) (insn, 0));
insns_removed++;
if (insns_removed == flag_sched_stalled_insns)
/* Remove no more than flag_sched_stalled_insns insns
from Q at a time. */
return insns_removed;
}
}
if (move_to_ready == false)
prev_link = link;
link = next_link;
} /* while link */
} /* if link */
} /* for stalls.. */
return insns_removed;
}
/* Print the ready list for debugging purposes. Callable from debugger. */
static void
debug_ready_list (struct ready_list *ready)
{
rtx *p;
int i;
if (ready->n_ready == 0)
{
fprintf (sched_dump, "\n");
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");
}
/* Search INSN for REG_SAVE_NOTE note pairs for
NOTE_INSN_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. */
void
reemit_notes (rtx insn)
{
rtx note, last = insn;
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));
last = emit_note_before (note_type, last);
remove_note (insn, note);
}
}
}
/* Move INSN. Reemit notes if needed. Update CFG, if needed. */
static void
move_insn (rtx insn, rtx last, rtx nt)
{
if (PREV_INSN (insn) != last)
{
basic_block bb;
rtx note;
int jump_p = 0;
bb = BLOCK_FOR_INSN (insn);
/* BB_HEAD is either LABEL or NOTE. */
gcc_assert (BB_HEAD (bb) != insn);
if (BB_END (bb) == insn)
/* If this is last instruction in BB, move end marker one
instruction up. */
{
/* Jumps are always placed at the end of basic block. */
jump_p = control_flow_insn_p (insn);
gcc_assert (!jump_p
|| ((common_sched_info->sched_pass_id == SCHED_RGN_PASS)
&& IS_SPECULATION_BRANCHY_CHECK_P (insn))
|| (common_sched_info->sched_pass_id
== SCHED_EBB_PASS));
gcc_assert (BLOCK_FOR_INSN (PREV_INSN (insn)) == bb);
BB_END (bb) = PREV_INSN (insn);
}
gcc_assert (BB_END (bb) != last);
if (jump_p)
/* We move the block note along with jump. */
{
gcc_assert (nt);
note = NEXT_INSN (insn);
while (NOTE_NOT_BB_P (note) && note != nt)
note = NEXT_INSN (note);
if (note != nt
&& (LABEL_P (note)
|| BARRIER_P (note)))
note = NEXT_INSN (note);
gcc_assert (NOTE_INSN_BASIC_BLOCK_P (note));
}
else
note = insn;
NEXT_INSN (PREV_INSN (insn)) = NEXT_INSN (note);
PREV_INSN (NEXT_INSN (note)) = PREV_INSN (insn);
NEXT_INSN (note) = NEXT_INSN (last);
PREV_INSN (NEXT_INSN (last)) = note;
NEXT_INSN (last) = insn;
PREV_INSN (insn) = last;
bb = BLOCK_FOR_INSN (last);
if (jump_p)
{
fix_jump_move (insn);
if (BLOCK_FOR_INSN (insn) != bb)
move_block_after_check (insn);
gcc_assert (BB_END (bb) == last);
}
df_insn_change_bb (insn, bb);
/* Update BB_END, if needed. */
if (BB_END (bb) == last)
BB_END (bb) = insn;
}
SCHED_GROUP_P (insn) = 0;
}
/* The following structure describe an entry of the stack of choices. */
struct choice_entry
{
/* Ordinal number of the issued insn in the ready queue. */
int index;
/* The number of the rest insns whose issues we should try. */
int rest;
/* The number of issued essential insns. */
int n;
/* State after issuing the insn. */
state_t state;
};
/* The following array is used to implement a stack of choices used in
function max_issue. */
static struct choice_entry *choice_stack;
/* The following variable value is number of essential insns issued on
the current cycle. An insn is essential one if it changes the
processors state. */
int cycle_issued_insns;
/* This holds the value of the target dfa_lookahead hook. */
int dfa_lookahead;
/* The following variable value is maximal number of tries of issuing
insns for the first cycle multipass insn scheduling. We define
this value as constant*(DFA_LOOKAHEAD**ISSUE_RATE). We would not
need this constraint if all real insns (with non-negative codes)
had reservations because in this case the algorithm complexity is
O(DFA_LOOKAHEAD**ISSUE_RATE). Unfortunately, the dfa descriptions
might be incomplete and such insn might occur. For such
descriptions, the complexity of algorithm (without the constraint)
could achieve DFA_LOOKAHEAD ** N , where N is the queue length. */
static int max_lookahead_tries;
/* The following value is value of hook
`first_cycle_multipass_dfa_lookahead' at the last call of
`max_issue'. */
static int cached_first_cycle_multipass_dfa_lookahead = 0;
/* The following value is value of `issue_rate' at the last call of
`sched_init'. */
static int cached_issue_rate = 0;
/* The following function returns maximal (or close to maximal) number
of insns which can be issued on the same cycle and one of which
insns is insns with the best rank (the first insn in READY). To
make this function tries different samples of ready insns. READY
is current queue `ready'. Global array READY_TRY reflects what
insns are already issued in this try. MAX_POINTS is the sum of points
of all instructions in READY. The function stops immediately,
if it reached the such a solution, that all instruction can be issued.
INDEX will contain index of the best insn in READY. The following
function is used only for first cycle multipass scheduling.
PRIVILEGED_N >= 0
This function expects recognized insns only. All USEs,
CLOBBERs, etc must be filtered elsewhere. */
int
max_issue (struct ready_list *ready, int privileged_n, state_t state,
int *index)
{
int n, i, all, n_ready, best, delay, tries_num, points = -1, max_points;
int more_issue;
struct choice_entry *top;
rtx insn;
n_ready = ready->n_ready;
gcc_assert (dfa_lookahead >= 1 && privileged_n >= 0
&& privileged_n <= n_ready);
/* Init MAX_LOOKAHEAD_TRIES. */
if (cached_first_cycle_multipass_dfa_lookahead != dfa_lookahead)
{
cached_first_cycle_multipass_dfa_lookahead = dfa_lookahead;
max_lookahead_tries = 100;
for (i = 0; i < issue_rate; i++)
max_lookahead_tries *= dfa_lookahead;
}
/* Init max_points. */
max_points = 0;
more_issue = issue_rate - cycle_issued_insns;
/* ??? We used to assert here that we never issue more insns than issue_rate.
However, some targets (e.g. MIPS/SB1) claim lower issue rate than can be
achieved to get better performance. Until these targets are fixed to use
scheduler hooks to manipulate insns priority instead, the assert should
be disabled.
gcc_assert (more_issue >= 0); */
for (i = 0; i < n_ready; i++)
if (!ready_try [i])
{
if (more_issue-- > 0)
max_points += ISSUE_POINTS (ready_element (ready, i));
else
break;
}
/* The number of the issued insns in the best solution. */
best = 0;
top = choice_stack;
/* Set initial state of the search. */
memcpy (top->state, state, dfa_state_size);
top->rest = dfa_lookahead;
top->n = 0;
/* Count the number of the insns to search among. */
for (all = i = 0; i < n_ready; i++)
if (!ready_try [i])
all++;
/* I is the index of the insn to try next. */
i = 0;
tries_num = 0;
for (;;)
{
if (/* If we've reached a dead end or searched enough of what we have
been asked... */
top->rest == 0
/* Or have nothing else to try. */
|| i >= n_ready)
{
/* ??? (... || i == n_ready). */
gcc_assert (i <= n_ready);
if (top == choice_stack)
break;
if (best < top - choice_stack)
{
if (privileged_n)
{
n = privileged_n;
/* Try to find issued privileged insn. */
while (n && !ready_try[--n]);
}
if (/* If all insns are equally good... */
privileged_n == 0
/* Or a privileged insn will be issued. */
|| ready_try[n])
/* Then we have a solution. */
{
best = top - choice_stack;
/* This is the index of the insn issued first in this
solution. */
*index = choice_stack [1].index;
points = top->n;
if (top->n == max_points || best == all)
break;
}
}
/* Set ready-list index to point to the last insn
('i++' below will advance it to the next insn). */
i = top->index;
/* Backtrack. */
ready_try [i] = 0;
top--;
memcpy (state, top->state, dfa_state_size);
}
else if (!ready_try [i])
{
tries_num++;
if (tries_num > max_lookahead_tries)
break;
insn = ready_element (ready, i);
delay = state_transition (state, insn);
if (delay < 0)
{
if (state_dead_lock_p (state))
top->rest = 0;
else
top->rest--;
n = top->n;
if (memcmp (top->state, state, dfa_state_size) != 0)
n += ISSUE_POINTS (insn);
/* Advance to the next choice_entry. */
top++;
/* Initialize it. */
top->rest = dfa_lookahead;
top->index = i;
top->n = n;
memcpy (top->state, state, dfa_state_size);
ready_try [i] = 1;
i = -1;
}
}
/* Increase ready-list index. */
i++;
}
/* Restore the original state of the DFA. */
memcpy (state, choice_stack->state, dfa_state_size);
return best;
}
/* The following function chooses insn from READY and modifies
READY. The following function is used only for first
cycle multipass scheduling.
Return:
-1 if cycle should be advanced,
0 if INSN_PTR is set to point to the desirable insn,
1 if choose_ready () should be restarted without advancing the cycle. */
static int
choose_ready (struct ready_list *ready, rtx *insn_ptr)
{
int lookahead;
if (dbg_cnt (sched_insn) == false)
{
rtx insn;
insn = next_nonnote_insn (last_scheduled_insn);
if (QUEUE_INDEX (insn) == QUEUE_READY)
/* INSN is in the ready_list. */
{
ready_remove_insn (insn);
*insn_ptr = insn;
return 0;
}
/* INSN is in the queue. Advance cycle to move it to the ready list. */
return -1;
}
lookahead = 0;
if (targetm.sched.first_cycle_multipass_dfa_lookahead)
lookahead = targetm.sched.first_cycle_multipass_dfa_lookahead ();
if (lookahead <= 0 || SCHED_GROUP_P (ready_element (ready, 0)))
{
*insn_ptr = ready_remove_first (ready);
return 0;
}
else
{
/* Try to choose the better insn. */
int index = 0, i, n;
rtx insn;
int try_data = 1, try_control = 1;
ds_t ts;
insn = ready_element (ready, 0);
if (INSN_CODE (insn) < 0)
{
*insn_ptr = ready_remove_first (ready);
return 0;
}
if (spec_info
&& spec_info->flags & (PREFER_NON_DATA_SPEC
| PREFER_NON_CONTROL_SPEC))
{
for (i = 0, n = ready->n_ready; i < n; i++)
{
rtx x;
ds_t s;
x = ready_element (ready, i);
s = TODO_SPEC (x);
if (spec_info->flags & PREFER_NON_DATA_SPEC
&& !(s & DATA_SPEC))
{
try_data = 0;
if (!(spec_info->flags & PREFER_NON_CONTROL_SPEC)
|| !try_control)
break;
}
if (spec_info->flags & PREFER_NON_CONTROL_SPEC
&& !(s & CONTROL_SPEC))
{
try_control = 0;
if (!(spec_info->flags & PREFER_NON_DATA_SPEC) || !try_data)
break;
}
}
}
ts = TODO_SPEC (insn);
if ((ts & SPECULATIVE)
&& (((!try_data && (ts & DATA_SPEC))
|| (!try_control && (ts & CONTROL_SPEC)))
|| (targetm.sched.first_cycle_multipass_dfa_lookahead_guard_spec
&& !targetm.sched
.first_cycle_multipass_dfa_lookahead_guard_spec (insn))))
/* Discard speculative instruction that stands first in the ready
list. */
{
change_queue_index (insn, 1);
return 1;
}
ready_try[0] = 0;
for (i = 1; i < ready->n_ready; i++)
{
insn = ready_element (ready, i);
ready_try [i]
= ((!try_data && (TODO_SPEC (insn) & DATA_SPEC))
|| (!try_control && (TODO_SPEC (insn) & CONTROL_SPEC)));
}
/* Let the target filter the search space. */
for (i = 1; i < ready->n_ready; i++)
if (!ready_try[i])
{
insn = ready_element (ready, i);
#ifdef ENABLE_CHECKING
/* If this insn is recognizable we should have already
recognized it earlier.
??? Not very clear where this is supposed to be done.
See dep_cost_1. */
gcc_assert (INSN_CODE (insn) >= 0
|| recog_memoized (insn) < 0);
#endif
ready_try [i]
= (/* INSN_CODE check can be omitted here as it is also done later
in max_issue (). */
INSN_CODE (insn) < 0
|| (targetm.sched.first_cycle_multipass_dfa_lookahead_guard
&& !targetm.sched.first_cycle_multipass_dfa_lookahead_guard
(insn)));
}
if (max_issue (ready, 1, curr_state, &index) == 0)
{
*insn_ptr = ready_remove_first (ready);
if (sched_verbose >= 4)
fprintf (sched_dump, ";;\t\tChosen insn (but can't issue) : %s \n",
(*current_sched_info->print_insn) (*insn_ptr, 0));
return 0;
}
else
{
if (sched_verbose >= 4)
fprintf (sched_dump, ";;\t\tChosen insn : %s\n",
(*current_sched_info->print_insn)
(ready_element (ready, index), 0));
*insn_ptr = ready_remove (ready, index);
return 0;
}
}
}
/* Use forward list scheduling to rearrange insns of block pointed to by
TARGET_BB, possibly bringing insns from subsequent blocks in the same
region. */
void
schedule_block (basic_block *target_bb)
{
int i, first_cycle_insn_p;
int can_issue_more;
state_t temp_state = NULL; /* It is used for multipass scheduling. */
int sort_p, advance, start_clock_var;
/* 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. */
gcc_assert (head != tail || INSN_P (head));
haifa_recovery_bb_recently_added_p = false;
/* Debug info. */
if (sched_verbose)
dump_new_block_header (0, *target_bb, head, tail);
state_reset (curr_state);
/* Clear the ready list. */
ready.first = ready.veclen - 1;
ready.n_ready = 0;
/* It is used for first cycle multipass scheduling. */
temp_state = alloca (dfa_state_size);
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;
gcc_assert (NOTE_P (last_scheduled_insn)
&& BLOCK_FOR_INSN (last_scheduled_insn) == *target_bb);
/* Initialize INSN_QUEUE. Q_SIZE is the total number of insns in the
queue. */
q_ptr = 0;
q_size = 0;
insn_queue = XALLOCAVEC (rtx, max_insn_queue_index + 1);
memset (insn_queue, 0, (max_insn_queue_index + 1) * sizeof (rtx));
/* Start just before the beginning of time. */
clock_var = -1;
/* We need queue and ready lists and clock_var be initialized
in try_ready () (which is called through init_ready_list ()). */
(*current_sched_info->init_ready_list) ();
/* The algorithm is O(n^2) in the number of ready insns at any given
time in the worst case. Before reload we are more likely to have
big lists so truncate them to a reasonable size. */
if (!reload_completed && ready.n_ready > MAX_SCHED_READY_INSNS)
{
ready_sort (&ready);
/* Find first free-standing insn past MAX_SCHED_READY_INSNS. */
for (i = MAX_SCHED_READY_INSNS; i < ready.n_ready; i++)
if (!SCHED_GROUP_P (ready_element (&ready, i)))
break;
if (sched_verbose >= 2)
{
fprintf (sched_dump,
";;\t\tReady list on entry: %d insns\n", ready.n_ready);
fprintf (sched_dump,
";;\t\t before reload => truncated to %d insns\n", i);
}
/* Delay all insns past it for 1 cycle. If debug counter is
activated make an exception for the insn right after
last_scheduled_insn. */
{
rtx skip_insn;
if (dbg_cnt (sched_insn) == false)
skip_insn = next_nonnote_insn (last_scheduled_insn);
else
skip_insn = NULL_RTX;
while (i < ready.n_ready)
{
rtx insn;
insn = ready_remove (&ready, i);
if (insn != skip_insn)
queue_insn (insn, 1);
}
}
}
/* Now we can restore basic block notes and maintain precise cfg. */
restore_bb_notes (*target_bb);
last_clock_var = -1;
advance = 0;
sort_p = TRUE;
/* Loop until all the insns in BB are scheduled. */
while ((*current_sched_info->schedule_more_p) ())
{
do
{
start_clock_var = clock_var;
clock_var++;
advance_one_cycle ();
/* 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);
gcc_assert (ready.n_ready);
if (sched_verbose >= 2)
{
fprintf (sched_dump, ";;\t\tReady list after queue_to_ready: ");
debug_ready_list (&ready);
}
advance -= clock_var - start_clock_var;
}
while (advance > 0);
if (sort_p)
{
/* Sort the ready list based on priority. */
ready_sort (&ready);
if (sched_verbose >= 2)
{
fprintf (sched_dump, ";;\t\tReady list after ready_sort: ");
debug_ready_list (&ready);
}
}
/* Allow the target to reorder the list, typically for
better instruction bundling. */
if (sort_p && targetm.sched.reorder
&& (ready.n_ready == 0
|| !SCHED_GROUP_P (ready_element (&ready, 0))))
can_issue_more =
targetm.sched.reorder (sched_dump, sched_verbose,
ready_lastpos (&ready),
&ready.n_ready, clock_var);
else
can_issue_more = issue_rate;
first_cycle_insn_p = 1;
cycle_issued_insns = 0;
for (;;)
{
rtx insn;
int cost;
bool asm_p = false;
if (sched_verbose >= 2)
{
fprintf (sched_dump, ";;\tReady list (t = %3d): ",
clock_var);
debug_ready_list (&ready);
}
if (ready.n_ready == 0
&& can_issue_more
&& reload_completed)
{
/* Allow scheduling insns directly from the queue in case
there's nothing better to do (ready list is empty) but
there are still vacant dispatch slots in the current cycle. */
if (sched_verbose >= 6)
fprintf (sched_dump,";;\t\tSecond chance\n");
memcpy (temp_state, curr_state, dfa_state_size);
if (early_queue_to_ready (temp_state, &ready))
ready_sort (&ready);
}
if (ready.n_ready == 0 || !can_issue_more
|| state_dead_lock_p (curr_state)
|| !(*current_sched_info->schedule_more_p) ())
break;
/* Select and remove the insn from the ready list. */
if (sort_p)
{
int res;
insn = NULL_RTX;
res = choose_ready (&ready, &insn);
if (res < 0)
/* Finish cycle. */
break;
if (res > 0)
/* Restart choose_ready (). */
continue;
gcc_assert (insn != NULL_RTX);
}
else
insn = ready_remove_first (&ready);
if (targetm.sched.dfa_new_cycle
&& targetm.sched.dfa_new_cycle (sched_dump, sched_verbose,
insn, last_clock_var,
clock_var, &sort_p))
/* SORT_P is used by the target to override sorting
of the ready list. This is needed when the target
has modified its internal structures expecting that
the insn will be issued next. As we need the insn
to have the highest priority (so it will be returned by
the ready_remove_first call above), we invoke
ready_add (&ready, insn, true).
But, still, there is one issue: INSN can be later
discarded by scheduler's front end through
current_sched_info->can_schedule_ready_p, hence, won't
be issued next. */
{
ready_add (&ready, insn, true);
break;
}
sort_p = TRUE;
memcpy (temp_state, curr_state, dfa_state_size);
if (recog_memoized (insn) < 0)
{
asm_p = (GET_CODE (PATTERN (insn)) == ASM_INPUT
|| asm_noperands (PATTERN (insn)) >= 0);
if (!first_cycle_insn_p && asm_p)
/* This is asm insn which is tried to be issued on the
cycle not first. Issue it on the next cycle. */
cost = 1;
else
/* A USE insn, or something else we don't need to
understand. We can't pass these directly to
state_transition because it will trigger a
fatal error for unrecognizable insns. */
cost = 0;
}
else
{
cost = state_transition (temp_state, insn);
if (cost < 0)
cost = 0;
else if (cost == 0)
cost = 1;
}
if (cost >= 1)
{
queue_insn (insn, cost);
if (SCHED_GROUP_P (insn))
{
advance = cost;
break;
}
continue;
}
if (current_sched_info->can_schedule_ready_p
&& ! (*current_sched_info->can_schedule_ready_p) (insn))
/* We normally get here only if we don't want to move
insn from the split block. */
{
TODO_SPEC (insn) = (TODO_SPEC (insn) & ~SPECULATIVE) | HARD_DEP;
continue;
}
/* DECISION is made. */
if (TODO_SPEC (insn) & SPECULATIVE)
generate_recovery_code (insn);
if (control_flow_insn_p (last_scheduled_insn)
/* This is used to switch basic blocks by request
from scheduler front-end (actually, sched-ebb.c only).
This is used to process blocks with single fallthru
edge. If succeeding block has jump, it [jump] will try
move at the end of current bb, thus corrupting CFG. */
|| current_sched_info->advance_target_bb (*target_bb, insn))
{
*target_bb = current_sched_info->advance_target_bb
(*target_bb, 0);
if (sched_verbose)
{
rtx x;
x = next_real_insn (last_scheduled_insn);
gcc_assert (x);
dump_new_block_header (1, *target_bb, x, tail);
}
last_scheduled_insn = bb_note (*target_bb);
}
/* Update counters, etc in the scheduler's front end. */
(*current_sched_info->begin_schedule_ready) (insn,
last_scheduled_insn);
move_insn (insn, last_scheduled_insn, current_sched_info->next_tail);
reemit_notes (insn);
last_scheduled_insn = insn;
if (memcmp (curr_state, temp_state, dfa_state_size) != 0)
{
cycle_issued_insns++;
memcpy (curr_state, temp_state, dfa_state_size);
}
if (targetm.sched.variable_issue)
can_issue_more =
targetm.sched.variable_issue (sched_dump, sched_verbose,
insn, can_issue_more);
/* A naked CLOBBER or USE generates no instruction, so do
not count them against the issue rate. */
else if (GET_CODE (PATTERN (insn)) != USE
&& GET_CODE (PATTERN (insn)) != CLOBBER)
can_issue_more--;
advance = schedule_insn (insn);
/* After issuing an asm insn we should start a new cycle. */
if (advance == 0 && asm_p)
advance = 1;
if (advance != 0)
break;
first_cycle_insn_p = 0;
/* Sort the ready list based on priority. This must be
redone here, as schedule_insn may have readied additional
insns that will not be sorted correctly. */
if (ready.n_ready > 0)
ready_sort (&ready);
if (targetm.sched.reorder2
&& (ready.n_ready == 0
|| !SCHED_GROUP_P (ready_element (&ready, 0))))
{
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)
{
fprintf (sched_dump, ";;\tReady list (final): ");
debug_ready_list (&ready);
}
if (current_sched_info->queue_must_finish_empty)
/* Sanity check -- queue must be empty now. Meaningless if region has
multiple bbs. */
gcc_assert (!q_size && !ready.n_ready);
else
{
/* We must maintain QUEUE_INDEX between blocks in region. */
for (i = ready.n_ready - 1; i >= 0; i--)
{
rtx x;
x = ready_element (&ready, i);
QUEUE_INDEX (x) = QUEUE_NOWHERE;
TODO_SPEC (x) = (TODO_SPEC (x) & ~SPECULATIVE) | HARD_DEP;
}
if (q_size)
for (i = 0; i <= max_insn_queue_index; i++)
{
rtx link;
for (link = insn_queue[i]; link; link = XEXP (link, 1))
{
rtx x;
x = XEXP (link, 0);
QUEUE_INDEX (x) = QUEUE_NOWHERE;
TODO_SPEC (x) = (TODO_SPEC (x) & ~SPECULATIVE) | HARD_DEP;
}
free_INSN_LIST_list (&insn_queue[i]);
}
}
if (sched_verbose)
fprintf (sched_dump, ";; total time = %d\n", clock_var);
if (!current_sched_info->queue_must_finish_empty
|| haifa_recovery_bb_recently_added_p)
{
/* INSN_TICK (minimum clock tick at which the insn becomes
ready) may be not correct for the insn in the subsequent
blocks of the region. We should use a correct value of
`clock_var' or modify INSN_TICK. It is better to keep
clock_var value equal to 0 at the start of a basic block.
Therefore we modify INSN_TICK here. */
fix_inter_tick (NEXT_INSN (prev_head), last_scheduled_insn);
}
if (targetm.sched.md_finish)
{
targetm.sched.md_finish (sched_dump, sched_verbose);
/* Target might have added some instructions to the scheduled block
in its md_finish () hook. These new insns don't have any data
initialized and to identify them we extend h_i_d so that they'll
get zero luids. */
sched_init_luids (NULL, NULL, NULL, NULL);
}
if (sched_verbose)
fprintf (sched_dump, ";; new head = %d\n;; new tail = %d\n\n",
INSN_UID (head), INSN_UID (tail));
/* Update head/tail boundaries. */
head = NEXT_INSN (prev_head);
tail = last_scheduled_insn;
head = restore_other_notes (head, NULL);
current_sched_info->head = head;
current_sched_info->tail = tail;
}
/* Set_priorities: compute priority of each insn in the block. */
int
set_priorities (rtx head, rtx tail)
{
rtx insn;
int n_insn;
int sched_max_insns_priority =
current_sched_info->sched_max_insns_priority;
rtx prev_head;
if (head == tail && (! INSN_P (head)))
return 0;
n_insn = 0;
prev_head = PREV_INSN (head);
for (insn = tail; insn != prev_head; insn = PREV_INSN (insn))
{
if (!INSN_P (insn))
continue;
n_insn++;
(void) priority (insn);
gcc_assert (INSN_PRIORITY_KNOWN (insn));
sched_max_insns_priority = MAX (sched_max_insns_priority,
INSN_PRIORITY (insn));
}
current_sched_info->sched_max_insns_priority = sched_max_insns_priority;
return n_insn;
}
/* 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. */
void
setup_sched_dump (void)
{
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 some global state for the scheduler. This function works
with the common data shared between all the schedulers. It is called
from the scheduler specific initialization routine. */
void
sched_init (void)
{
/* Disable speculative loads in their presence if cc0 defined. */
#ifdef HAVE_cc0
flag_schedule_speculative_load = 0;
#endif
/* Initialize SPEC_INFO. */
if (targetm.sched.set_sched_flags)
{
spec_info = &spec_info_var;
targetm.sched.set_sched_flags (spec_info);
if (spec_info->mask != 0)
{
spec_info->data_weakness_cutoff =
(PARAM_VALUE (PARAM_SCHED_SPEC_PROB_CUTOFF) * MAX_DEP_WEAK) / 100;
spec_info->control_weakness_cutoff =
(PARAM_VALUE (PARAM_SCHED_SPEC_PROB_CUTOFF)
* REG_BR_PROB_BASE) / 100;
}
else
/* So we won't read anything accidentally. */
spec_info = NULL;
}
else
/* So we won't read anything accidentally. */
spec_info = 0;
/* Initialize issue_rate. */
if (targetm.sched.issue_rate)
issue_rate = targetm.sched.issue_rate ();
else
issue_rate = 1;
if (cached_issue_rate != issue_rate)
{
cached_issue_rate = issue_rate;
/* To invalidate max_lookahead_tries: */
cached_first_cycle_multipass_dfa_lookahead = 0;
}
if (targetm.sched.first_cycle_multipass_dfa_lookahead)
dfa_lookahead = targetm.sched.first_cycle_multipass_dfa_lookahead ();
else
dfa_lookahead = 0;
if (targetm.sched.init_dfa_pre_cycle_insn)
targetm.sched.init_dfa_pre_cycle_insn ();
if (targetm.sched.init_dfa_post_cycle_insn)
targetm.sched.init_dfa_post_cycle_insn ();
dfa_start ();
dfa_state_size = state_size ();
init_alias_analysis ();
df_set_flags (DF_LR_RUN_DCE);
df_note_add_problem ();
/* More problems needed for interloop dep calculation in SMS. */
if (common_sched_info->sched_pass_id == SCHED_SMS_PASS)
{
df_rd_add_problem ();
df_chain_add_problem (DF_DU_CHAIN + DF_UD_CHAIN);
}
df_analyze ();
/* Do not run DCE after reload, as this can kill nops inserted
by bundling. */
if (reload_completed)
df_clear_flags (DF_LR_RUN_DCE);
regstat_compute_calls_crossed ();
if (targetm.sched.md_init_global)
targetm.sched.md_init_global (sched_dump, sched_verbose,
get_max_uid () + 1);
curr_state = xmalloc (dfa_state_size);
}
static void haifa_init_only_bb (basic_block, basic_block);
/* Initialize data structures specific to the Haifa scheduler. */
void
haifa_sched_init (void)
{
setup_sched_dump ();
sched_init ();
if (spec_info != NULL)
{
sched_deps_info->use_deps_list = 1;
sched_deps_info->generate_spec_deps = 1;
}
/* Initialize luids, dependency caches, target and h_i_d for the
whole function. */
{
bb_vec_t bbs = VEC_alloc (basic_block, heap, n_basic_blocks);
basic_block bb;
sched_init_bbs ();
FOR_EACH_BB (bb)
VEC_quick_push (basic_block, bbs, bb);
sched_init_luids (bbs, NULL, NULL, NULL);
sched_deps_init (true);
sched_extend_target ();
haifa_init_h_i_d (bbs, NULL, NULL, NULL);
VEC_free (basic_block, heap, bbs);
}
sched_init_only_bb = haifa_init_only_bb;
sched_split_block = sched_split_block_1;
sched_create_empty_bb = sched_create_empty_bb_1;
haifa_recovery_bb_ever_added_p = false;
#ifdef ENABLE_CHECKING
/* This is used preferably for finding bugs in check_cfg () itself.
We must call sched_bbs_init () before check_cfg () because check_cfg ()
assumes that the last insn in the last bb has a non-null successor. */
check_cfg (0, 0);
#endif
nr_begin_data = nr_begin_control = nr_be_in_data = nr_be_in_control = 0;
before_recovery = 0;
after_recovery = 0;
}
/* Finish work with the data specific to the Haifa scheduler. */
void
haifa_sched_finish (void)
{
sched_create_empty_bb = NULL;
sched_split_block = NULL;
sched_init_only_bb = NULL;
if (spec_info && spec_info->dump)
{
char c = reload_completed ? 'a' : 'b';
fprintf (spec_info->dump,
";; %s:\n", current_function_name ());
fprintf (spec_info->dump,
";; Procedure %cr-begin-data-spec motions == %d\n",
c, nr_begin_data);
fprintf (spec_info->dump,
";; Procedure %cr-be-in-data-spec motions == %d\n",
c, nr_be_in_data);
fprintf (spec_info->dump,
";; Procedure %cr-begin-control-spec motions == %d\n",
c, nr_begin_control);
fprintf (spec_info->dump,
";; Procedure %cr-be-in-control-spec motions == %d\n",
c, nr_be_in_control);
}
/* Finalize h_i_d, dependency caches, and luids for the whole
function. Target will be finalized in md_global_finish (). */
sched_deps_finish ();
sched_finish_luids ();
current_sched_info = NULL;
sched_finish ();
}
/* Free global data used during insn scheduling. This function works with
the common data shared between the schedulers. */
void
sched_finish (void)
{
haifa_finish_h_i_d ();
free (curr_state);
if (targetm.sched.md_finish_global)
targetm.sched.md_finish_global (sched_dump, sched_verbose);
end_alias_analysis ();
regstat_free_calls_crossed ();
dfa_finish ();
#ifdef ENABLE_CHECKING
/* After reload ia64 backend clobbers CFG, so can't check anything. */
if (!reload_completed)
check_cfg (0, 0);
#endif
}
/* Fix INSN_TICKs of the instructions in the current block as well as
INSN_TICKs of their dependents.
HEAD and TAIL are the begin and the end of the current scheduled block. */
static void
fix_inter_tick (rtx head, rtx tail)
{
/* Set of instructions with corrected INSN_TICK. */
bitmap_head processed;
/* ??? It is doubtful if we should assume that cycle advance happens on
basic block boundaries. Basically insns that are unconditionally ready
on the start of the block are more preferable then those which have
a one cycle dependency over insn from the previous block. */
int next_clock = clock_var + 1;
bitmap_initialize (&processed, 0);
/* Iterates over scheduled instructions and fix their INSN_TICKs and
INSN_TICKs of dependent instructions, so that INSN_TICKs are consistent
across different blocks. */
for (tail = NEXT_INSN (tail); head != tail; head = NEXT_INSN (head))
{
if (INSN_P (head))
{
int tick;
sd_iterator_def sd_it;
dep_t dep;
tick = INSN_TICK (head);
gcc_assert (tick >= MIN_TICK);
/* Fix INSN_TICK of instruction from just scheduled block. */
if (!bitmap_bit_p (&processed, INSN_LUID (head)))
{
bitmap_set_bit (&processed, INSN_LUID (head));
tick -= next_clock;
if (tick < MIN_TICK)
tick = MIN_TICK;
INSN_TICK (head) = tick;
}
FOR_EACH_DEP (head, SD_LIST_RES_FORW, sd_it, dep)
{
rtx next;
next = DEP_CON (dep);
tick = INSN_TICK (next);
if (tick != INVALID_TICK
/* If NEXT has its INSN_TICK calculated, fix it.
If not - it will be properly calculated from
scratch later in fix_tick_ready. */
&& !bitmap_bit_p (&processed, INSN_LUID (next)))
{
bitmap_set_bit (&processed, INSN_LUID (next));
tick -= next_clock;
if (tick < MIN_TICK)
tick = MIN_TICK;
if (tick > INTER_TICK (next))
INTER_TICK (next) = tick;
else
tick = INTER_TICK (next);
INSN_TICK (next) = tick;
}
}
}
}
bitmap_clear (&processed);
}
static int haifa_speculate_insn (rtx, ds_t, rtx *);
/* Check if NEXT is ready to be added to the ready or queue list.
If "yes", add it to the proper list.
Returns:
-1 - is not ready yet,
0 - added to the ready list,
0 < N - queued for N cycles. */
int
try_ready (rtx next)
{
ds_t old_ts, *ts;
ts = &TODO_SPEC (next);
old_ts = *ts;
gcc_assert (!(old_ts & ~(SPECULATIVE | HARD_DEP))
&& ((old_ts & HARD_DEP)
|| (old_ts & SPECULATIVE)));
if (sd_lists_empty_p (next, SD_LIST_BACK))
/* NEXT has all its dependencies resolved. */
{
/* Remove HARD_DEP bit from NEXT's status. */
*ts &= ~HARD_DEP;
if (current_sched_info->flags & DO_SPECULATION)
/* Remove all speculative bits from NEXT's status. */
*ts &= ~SPECULATIVE;
}
else
{
/* One of the NEXT's dependencies has been resolved.
Recalculate NEXT's status. */
*ts &= ~SPECULATIVE & ~HARD_DEP;
if (sd_lists_empty_p (next, SD_LIST_HARD_BACK))
/* Now we've got NEXT with speculative deps only.
1. Look at the deps to see what we have to do.
2. Check if we can do 'todo'. */
{
sd_iterator_def sd_it;
dep_t dep;
bool first_p = true;
FOR_EACH_DEP (next, SD_LIST_BACK, sd_it, dep)
{
ds_t ds = DEP_STATUS (dep) & SPECULATIVE;
if (first_p)
{
first_p = false;
*ts = ds;
}
else
*ts = ds_merge (*ts, ds);
}
if (ds_weak (*ts) < spec_info->data_weakness_cutoff)
/* Too few points. */
*ts = (*ts & ~SPECULATIVE) | HARD_DEP;
}
else
*ts |= HARD_DEP;
}
if (*ts & HARD_DEP)
gcc_assert (*ts == old_ts
&& QUEUE_INDEX (next) == QUEUE_NOWHERE);
else if (current_sched_info->new_ready)
*ts = current_sched_info->new_ready (next, *ts);
/* * if !(old_ts & SPECULATIVE) (e.g. HARD_DEP or 0), then insn might
have its original pattern or changed (speculative) one. This is due
to changing ebb in region scheduling.
* But if (old_ts & SPECULATIVE), then we are pretty sure that insn
has speculative pattern.
We can't assert (!(*ts & HARD_DEP) || *ts == old_ts) here because
control-speculative NEXT could have been discarded by sched-rgn.c
(the same case as when discarded by can_schedule_ready_p ()). */
if ((*ts & SPECULATIVE)
/* If (old_ts == *ts), then (old_ts & SPECULATIVE) and we don't
need to change anything. */
&& *ts != old_ts)
{
int res;
rtx new_pat;
gcc_assert ((*ts & SPECULATIVE) && !(*ts & ~SPECULATIVE));
res = haifa_speculate_insn (next, *ts, &new_pat);
switch (res)
{
case -1:
/* It would be nice to change DEP_STATUS of all dependences,
which have ((DEP_STATUS & SPECULATIVE) == *ts) to HARD_DEP,
so we won't reanalyze anything. */
*ts = (*ts & ~SPECULATIVE) | HARD_DEP;
break;
case 0:
/* We follow the rule, that every speculative insn
has non-null ORIG_PAT. */
if (!ORIG_PAT (next))
ORIG_PAT (next) = PATTERN (next);
break;
case 1:
if (!ORIG_PAT (next))
/* If we gonna to overwrite the original pattern of insn,
save it. */
ORIG_PAT (next) = PATTERN (next);
haifa_change_pattern (next, new_pat);
break;
default:
gcc_unreachable ();
}
}
/* We need to restore pattern only if (*ts == 0), because otherwise it is
either correct (*ts & SPECULATIVE),
or we simply don't care (*ts & HARD_DEP). */
gcc_assert (!ORIG_PAT (next)
|| !IS_SPECULATION_BRANCHY_CHECK_P (next));
if (*ts & HARD_DEP)
{
/* We can't assert (QUEUE_INDEX (next) == QUEUE_NOWHERE) here because
control-speculative NEXT could have been discarded by sched-rgn.c
(the same case as when discarded by can_schedule_ready_p ()). */
/*gcc_assert (QUEUE_INDEX (next) == QUEUE_NOWHERE);*/
change_queue_index (next, QUEUE_NOWHERE);
return -1;
}
else if (!(*ts & BEGIN_SPEC) && ORIG_PAT (next) && !IS_SPECULATION_CHECK_P (next))
/* We should change pattern of every previously speculative
instruction - and we determine if NEXT was speculative by using
ORIG_PAT field. Except one case - speculation checks have ORIG_PAT
pat too, so skip them. */
{
haifa_change_pattern (next, ORIG_PAT (next));
ORIG_PAT (next) = 0;
}
if (sched_verbose >= 2)
{
int s = TODO_SPEC (next);
fprintf (sched_dump, ";;\t\tdependencies resolved: insn %s",
(*current_sched_info->print_insn) (next, 0));
if (spec_info && spec_info->dump)
{
if (s & BEGIN_DATA)
fprintf (spec_info->dump, "; data-spec;");
if (s & BEGIN_CONTROL)
fprintf (spec_info->dump, "; control-spec;");
if (s & BE_IN_CONTROL)
fprintf (spec_info->dump, "; in-control-spec;");
}
fprintf (sched_dump, "\n");
}
adjust_priority (next);
return fix_tick_ready (next);
}
/* Calculate INSN_TICK of NEXT and add it to either ready or queue list. */
static int
fix_tick_ready (rtx next)
{
int tick, delay;
if (!sd_lists_empty_p (next, SD_LIST_RES_BACK))
{
int full_p;
sd_iterator_def sd_it;
dep_t dep;
tick = INSN_TICK (next);
/* if tick is not equal to INVALID_TICK, then update
INSN_TICK of NEXT with the most recent resolved dependence
cost. Otherwise, recalculate from scratch. */
full_p = (tick == INVALID_TICK);
FOR_EACH_DEP (next, SD_LIST_RES_BACK, sd_it, dep)
{
rtx pro = DEP_PRO (dep);
int tick1;
gcc_assert (INSN_TICK (pro) >= MIN_TICK);
tick1 = INSN_TICK (pro) + dep_cost (dep);
if (tick1 > tick)
tick = tick1;
if (!full_p)
break;
}
}
else
tick = -1;
INSN_TICK (next) =