3120 lines
88 KiB
C
3120 lines
88 KiB
C
/* Instruction scheduling pass.
|
||
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998,
|
||
1999, 2000, 2001, 2002 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 2, 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 COPYING. If not, write to the Free
|
||
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||
02111-1307, USA. */
|
||
|
||
/* This pass implements list scheduling within basic blocks. It is
|
||
run twice: (1) after flow analysis, but before register allocation,
|
||
and (2) after register allocation.
|
||
|
||
The first run performs interblock scheduling, moving insns between
|
||
different blocks in the same "region", and the second runs only
|
||
basic block scheduling.
|
||
|
||
Interblock motions performed are useful motions and speculative
|
||
motions, including speculative loads. Motions requiring code
|
||
duplication are not supported. The identification of motion type
|
||
and the check for validity of speculative motions requires
|
||
construction and analysis of the function's control flow graph.
|
||
|
||
The main entry point for this pass is schedule_insns(), called for
|
||
each function. The work of the scheduler is organized in three
|
||
levels: (1) function level: insns are subject to splitting,
|
||
control-flow-graph is constructed, regions are computed (after
|
||
reload, each region is of one block), (2) region level: control
|
||
flow graph attributes required for interblock scheduling are
|
||
computed (dominators, reachability, etc.), data dependences and
|
||
priorities are computed, and (3) block level: insns in the block
|
||
are actually scheduled. */
|
||
|
||
#include "config.h"
|
||
#include "system.h"
|
||
#include "toplev.h"
|
||
#include "rtl.h"
|
||
#include "tm_p.h"
|
||
#include "hard-reg-set.h"
|
||
#include "basic-block.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 "cfglayout.h"
|
||
#include "sched-int.h"
|
||
#include "target.h"
|
||
|
||
/* Define when we want to do count REG_DEAD notes before and after scheduling
|
||
for sanity checking. We can't do that when conditional execution is used,
|
||
as REG_DEAD exist only for unconditional deaths. */
|
||
|
||
#if !defined (HAVE_conditional_execution) && defined (ENABLE_CHECKING)
|
||
#define CHECK_DEAD_NOTES 1
|
||
#else
|
||
#define CHECK_DEAD_NOTES 0
|
||
#endif
|
||
|
||
|
||
#ifdef INSN_SCHEDULING
|
||
/* Some accessor macros for h_i_d members only used within this file. */
|
||
#define INSN_REF_COUNT(INSN) (h_i_d[INSN_UID (INSN)].ref_count)
|
||
#define FED_BY_SPEC_LOAD(insn) (h_i_d[INSN_UID (insn)].fed_by_spec_load)
|
||
#define IS_LOAD_INSN(insn) (h_i_d[INSN_UID (insn)].is_load_insn)
|
||
|
||
#define MAX_RGN_BLOCKS 10
|
||
#define MAX_RGN_INSNS 100
|
||
|
||
/* nr_inter/spec counts interblock/speculative motion for the function. */
|
||
static int nr_inter, nr_spec;
|
||
|
||
/* Control flow graph edges are kept in circular lists. */
|
||
typedef struct
|
||
{
|
||
int from_block;
|
||
int to_block;
|
||
int next_in;
|
||
int next_out;
|
||
}
|
||
haifa_edge;
|
||
static haifa_edge *edge_table;
|
||
|
||
#define NEXT_IN(edge) (edge_table[edge].next_in)
|
||
#define NEXT_OUT(edge) (edge_table[edge].next_out)
|
||
#define FROM_BLOCK(edge) (edge_table[edge].from_block)
|
||
#define TO_BLOCK(edge) (edge_table[edge].to_block)
|
||
|
||
/* Number of edges in the control flow graph. (In fact, larger than
|
||
that by 1, since edge 0 is unused.) */
|
||
static int nr_edges;
|
||
|
||
/* Circular list of incoming/outgoing edges of a block. */
|
||
static int *in_edges;
|
||
static int *out_edges;
|
||
|
||
#define IN_EDGES(block) (in_edges[block])
|
||
#define OUT_EDGES(block) (out_edges[block])
|
||
|
||
static int is_cfg_nonregular PARAMS ((void));
|
||
static int build_control_flow PARAMS ((struct edge_list *));
|
||
static void new_edge PARAMS ((int, int));
|
||
|
||
/* A region is the main entity for interblock scheduling: insns
|
||
are allowed to move between blocks in the same region, along
|
||
control flow graph edges, in the 'up' direction. */
|
||
typedef struct
|
||
{
|
||
int rgn_nr_blocks; /* Number of blocks in region. */
|
||
int rgn_blocks; /* cblocks in the region (actually index in rgn_bb_table). */
|
||
}
|
||
region;
|
||
|
||
/* Number of regions in the procedure. */
|
||
static int nr_regions;
|
||
|
||
/* Table of region descriptions. */
|
||
static region *rgn_table;
|
||
|
||
/* Array of lists of regions' blocks. */
|
||
static int *rgn_bb_table;
|
||
|
||
/* Topological order of blocks in the region (if b2 is reachable from
|
||
b1, block_to_bb[b2] > block_to_bb[b1]). Note: A basic block is
|
||
always referred to by either block or b, while its topological
|
||
order name (in the region) is refered to by bb. */
|
||
static int *block_to_bb;
|
||
|
||
/* The number of the region containing a block. */
|
||
static int *containing_rgn;
|
||
|
||
#define RGN_NR_BLOCKS(rgn) (rgn_table[rgn].rgn_nr_blocks)
|
||
#define RGN_BLOCKS(rgn) (rgn_table[rgn].rgn_blocks)
|
||
#define BLOCK_TO_BB(block) (block_to_bb[block])
|
||
#define CONTAINING_RGN(block) (containing_rgn[block])
|
||
|
||
void debug_regions PARAMS ((void));
|
||
static void find_single_block_region PARAMS ((void));
|
||
static void find_rgns PARAMS ((struct edge_list *, dominance_info));
|
||
static int too_large PARAMS ((int, int *, int *));
|
||
|
||
extern void debug_live PARAMS ((int, int));
|
||
|
||
/* Blocks of the current region being scheduled. */
|
||
static int current_nr_blocks;
|
||
static int current_blocks;
|
||
|
||
/* The mapping from bb to block. */
|
||
#define BB_TO_BLOCK(bb) (rgn_bb_table[current_blocks + (bb)])
|
||
|
||
typedef struct
|
||
{
|
||
int *first_member; /* Pointer to the list start in bitlst_table. */
|
||
int nr_members; /* The number of members of the bit list. */
|
||
}
|
||
bitlst;
|
||
|
||
static int bitlst_table_last;
|
||
static int bitlst_table_size;
|
||
static int *bitlst_table;
|
||
|
||
static void extract_bitlst PARAMS ((sbitmap, bitlst *));
|
||
|
||
/* Target info declarations.
|
||
|
||
The block currently being scheduled is referred to as the "target" block,
|
||
while other blocks in the region from which insns can be moved to the
|
||
target are called "source" blocks. The candidate structure holds info
|
||
about such sources: are they valid? Speculative? Etc. */
|
||
typedef bitlst bblst;
|
||
typedef struct
|
||
{
|
||
char is_valid;
|
||
char is_speculative;
|
||
int src_prob;
|
||
bblst split_bbs;
|
||
bblst update_bbs;
|
||
}
|
||
candidate;
|
||
|
||
static candidate *candidate_table;
|
||
|
||
/* A speculative motion requires checking live information on the path
|
||
from 'source' to 'target'. The split blocks are those to be checked.
|
||
After a speculative motion, live information should be modified in
|
||
the 'update' blocks.
|
||
|
||
Lists of split and update blocks for each candidate of the current
|
||
target are in array bblst_table. */
|
||
static int *bblst_table, bblst_size, bblst_last;
|
||
|
||
#define IS_VALID(src) ( candidate_table[src].is_valid )
|
||
#define IS_SPECULATIVE(src) ( candidate_table[src].is_speculative )
|
||
#define SRC_PROB(src) ( candidate_table[src].src_prob )
|
||
|
||
/* The bb being currently scheduled. */
|
||
static int target_bb;
|
||
|
||
/* List of edges. */
|
||
typedef bitlst edgelst;
|
||
|
||
/* Target info functions. */
|
||
static void split_edges PARAMS ((int, int, edgelst *));
|
||
static void compute_trg_info PARAMS ((int));
|
||
void debug_candidate PARAMS ((int));
|
||
void debug_candidates PARAMS ((int));
|
||
|
||
/* Dominators array: dom[i] contains the sbitmap of dominators of
|
||
bb i in the region. */
|
||
static sbitmap *dom;
|
||
|
||
/* bb 0 is the only region entry. */
|
||
#define IS_RGN_ENTRY(bb) (!bb)
|
||
|
||
/* Is bb_src dominated by bb_trg. */
|
||
#define IS_DOMINATED(bb_src, bb_trg) \
|
||
( TEST_BIT (dom[bb_src], bb_trg) )
|
||
|
||
/* Probability: Prob[i] is a float in [0, 1] which is the probability
|
||
of bb i relative to the region entry. */
|
||
static float *prob;
|
||
|
||
/* The probability of bb_src, relative to bb_trg. Note, that while the
|
||
'prob[bb]' is a float in [0, 1], this macro returns an integer
|
||
in [0, 100]. */
|
||
#define GET_SRC_PROB(bb_src, bb_trg) ((int) (100.0 * (prob[bb_src] / \
|
||
prob[bb_trg])))
|
||
|
||
/* Bit-set of edges, where bit i stands for edge i. */
|
||
typedef sbitmap edgeset;
|
||
|
||
/* Number of edges in the region. */
|
||
static int rgn_nr_edges;
|
||
|
||
/* Array of size rgn_nr_edges. */
|
||
static int *rgn_edges;
|
||
|
||
|
||
/* Mapping from each edge in the graph to its number in the rgn. */
|
||
static int *edge_to_bit;
|
||
#define EDGE_TO_BIT(edge) (edge_to_bit[edge])
|
||
|
||
/* The split edges of a source bb is different for each target
|
||
bb. In order to compute this efficiently, the 'potential-split edges'
|
||
are computed for each bb prior to scheduling a region. This is actually
|
||
the split edges of each bb relative to the region entry.
|
||
|
||
pot_split[bb] is the set of potential split edges of bb. */
|
||
static edgeset *pot_split;
|
||
|
||
/* For every bb, a set of its ancestor edges. */
|
||
static edgeset *ancestor_edges;
|
||
|
||
static void compute_dom_prob_ps PARAMS ((int));
|
||
|
||
#define INSN_PROBABILITY(INSN) (SRC_PROB (BLOCK_TO_BB (BLOCK_NUM (INSN))))
|
||
#define IS_SPECULATIVE_INSN(INSN) (IS_SPECULATIVE (BLOCK_TO_BB (BLOCK_NUM (INSN))))
|
||
#define INSN_BB(INSN) (BLOCK_TO_BB (BLOCK_NUM (INSN)))
|
||
|
||
/* Parameters affecting the decision of rank_for_schedule().
|
||
??? Nope. But MIN_PROBABILITY is used in copmute_trg_info. */
|
||
#define MIN_PROBABILITY 40
|
||
|
||
/* Speculative scheduling functions. */
|
||
static int check_live_1 PARAMS ((int, rtx));
|
||
static void update_live_1 PARAMS ((int, rtx));
|
||
static int check_live PARAMS ((rtx, int));
|
||
static void update_live PARAMS ((rtx, int));
|
||
static void set_spec_fed PARAMS ((rtx));
|
||
static int is_pfree PARAMS ((rtx, int, int));
|
||
static int find_conditional_protection PARAMS ((rtx, int));
|
||
static int is_conditionally_protected PARAMS ((rtx, int, int));
|
||
static int may_trap_exp PARAMS ((rtx, int));
|
||
static int haifa_classify_insn PARAMS ((rtx));
|
||
static int is_prisky PARAMS ((rtx, int, int));
|
||
static int is_exception_free PARAMS ((rtx, int, int));
|
||
|
||
static bool sets_likely_spilled PARAMS ((rtx));
|
||
static void sets_likely_spilled_1 PARAMS ((rtx, rtx, void *));
|
||
static void add_branch_dependences PARAMS ((rtx, rtx));
|
||
static void compute_block_backward_dependences PARAMS ((int));
|
||
void debug_dependencies PARAMS ((void));
|
||
|
||
static void init_regions PARAMS ((void));
|
||
static void schedule_region PARAMS ((int));
|
||
static rtx concat_INSN_LIST PARAMS ((rtx, rtx));
|
||
static void concat_insn_mem_list PARAMS ((rtx, rtx, rtx *, rtx *));
|
||
static void propagate_deps PARAMS ((int, struct deps *));
|
||
static void free_pending_lists PARAMS ((void));
|
||
|
||
/* Functions for construction of the control flow graph. */
|
||
|
||
/* Return 1 if control flow graph should not be constructed, 0 otherwise.
|
||
|
||
We decide not to build the control flow graph if there is possibly more
|
||
than one entry to the function, if computed branches exist, of if we
|
||
have nonlocal gotos. */
|
||
|
||
static int
|
||
is_cfg_nonregular ()
|
||
{
|
||
basic_block b;
|
||
rtx insn;
|
||
RTX_CODE code;
|
||
|
||
/* If we have a label that could be the target of a nonlocal goto, then
|
||
the cfg is not well structured. */
|
||
if (nonlocal_goto_handler_labels)
|
||
return 1;
|
||
|
||
/* If we have any forced labels, then the cfg is not well structured. */
|
||
if (forced_labels)
|
||
return 1;
|
||
|
||
/* If this function has a computed jump, then we consider the cfg
|
||
not well structured. */
|
||
if (current_function_has_computed_jump)
|
||
return 1;
|
||
|
||
/* If we have exception handlers, then we consider the cfg not well
|
||
structured. ?!? We should be able to handle this now that flow.c
|
||
computes an accurate cfg for EH. */
|
||
if (current_function_has_exception_handlers ())
|
||
return 1;
|
||
|
||
/* If we have non-jumping insns which refer to labels, then we consider
|
||
the cfg not well structured. */
|
||
/* Check for labels referred to other thn by jumps. */
|
||
FOR_EACH_BB (b)
|
||
for (insn = b->head;; insn = NEXT_INSN (insn))
|
||
{
|
||
code = GET_CODE (insn);
|
||
if (GET_RTX_CLASS (code) == 'i' && code != JUMP_INSN)
|
||
{
|
||
rtx note = find_reg_note (insn, REG_LABEL, NULL_RTX);
|
||
|
||
if (note
|
||
&& ! (GET_CODE (NEXT_INSN (insn)) == JUMP_INSN
|
||
&& find_reg_note (NEXT_INSN (insn), REG_LABEL,
|
||
XEXP (note, 0))))
|
||
return 1;
|
||
}
|
||
|
||
if (insn == b->end)
|
||
break;
|
||
}
|
||
|
||
/* All the tests passed. Consider the cfg well structured. */
|
||
return 0;
|
||
}
|
||
|
||
/* Build the control flow graph and set nr_edges.
|
||
|
||
Instead of trying to build a cfg ourselves, we rely on flow to
|
||
do it for us. Stamp out useless code (and bug) duplication.
|
||
|
||
Return nonzero if an irregularity in the cfg is found which would
|
||
prevent cross block scheduling. */
|
||
|
||
static int
|
||
build_control_flow (edge_list)
|
||
struct edge_list *edge_list;
|
||
{
|
||
int i, unreachable, num_edges;
|
||
basic_block b;
|
||
|
||
/* This already accounts for entry/exit edges. */
|
||
num_edges = NUM_EDGES (edge_list);
|
||
|
||
/* Unreachable loops with more than one basic block are detected
|
||
during the DFS traversal in find_rgns.
|
||
|
||
Unreachable loops with a single block are detected here. This
|
||
test is redundant with the one in find_rgns, but it's much
|
||
cheaper to go ahead and catch the trivial case here. */
|
||
unreachable = 0;
|
||
FOR_EACH_BB (b)
|
||
{
|
||
if (b->pred == NULL
|
||
|| (b->pred->src == b
|
||
&& b->pred->pred_next == NULL))
|
||
unreachable = 1;
|
||
}
|
||
|
||
/* ??? We can kill these soon. */
|
||
in_edges = (int *) xcalloc (last_basic_block, sizeof (int));
|
||
out_edges = (int *) xcalloc (last_basic_block, sizeof (int));
|
||
edge_table = (haifa_edge *) xcalloc (num_edges, sizeof (haifa_edge));
|
||
|
||
nr_edges = 0;
|
||
for (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (edge_list, i);
|
||
|
||
if (e->dest != EXIT_BLOCK_PTR
|
||
&& e->src != ENTRY_BLOCK_PTR)
|
||
new_edge (e->src->index, e->dest->index);
|
||
}
|
||
|
||
/* Increment by 1, since edge 0 is unused. */
|
||
nr_edges++;
|
||
|
||
return unreachable;
|
||
}
|
||
|
||
/* Record an edge in the control flow graph from SOURCE to TARGET.
|
||
|
||
In theory, this is redundant with the s_succs computed above, but
|
||
we have not converted all of haifa to use information from the
|
||
integer lists. */
|
||
|
||
static void
|
||
new_edge (source, target)
|
||
int source, target;
|
||
{
|
||
int e, next_edge;
|
||
int curr_edge, fst_edge;
|
||
|
||
/* Check for duplicates. */
|
||
fst_edge = curr_edge = OUT_EDGES (source);
|
||
while (curr_edge)
|
||
{
|
||
if (FROM_BLOCK (curr_edge) == source
|
||
&& TO_BLOCK (curr_edge) == target)
|
||
{
|
||
return;
|
||
}
|
||
|
||
curr_edge = NEXT_OUT (curr_edge);
|
||
|
||
if (fst_edge == curr_edge)
|
||
break;
|
||
}
|
||
|
||
e = ++nr_edges;
|
||
|
||
FROM_BLOCK (e) = source;
|
||
TO_BLOCK (e) = target;
|
||
|
||
if (OUT_EDGES (source))
|
||
{
|
||
next_edge = NEXT_OUT (OUT_EDGES (source));
|
||
NEXT_OUT (OUT_EDGES (source)) = e;
|
||
NEXT_OUT (e) = next_edge;
|
||
}
|
||
else
|
||
{
|
||
OUT_EDGES (source) = e;
|
||
NEXT_OUT (e) = e;
|
||
}
|
||
|
||
if (IN_EDGES (target))
|
||
{
|
||
next_edge = NEXT_IN (IN_EDGES (target));
|
||
NEXT_IN (IN_EDGES (target)) = e;
|
||
NEXT_IN (e) = next_edge;
|
||
}
|
||
else
|
||
{
|
||
IN_EDGES (target) = e;
|
||
NEXT_IN (e) = e;
|
||
}
|
||
}
|
||
|
||
/* Translate a bit-set SET to a list BL of the bit-set members. */
|
||
|
||
static void
|
||
extract_bitlst (set, bl)
|
||
sbitmap set;
|
||
bitlst *bl;
|
||
{
|
||
int i;
|
||
|
||
/* bblst table space is reused in each call to extract_bitlst. */
|
||
bitlst_table_last = 0;
|
||
|
||
bl->first_member = &bitlst_table[bitlst_table_last];
|
||
bl->nr_members = 0;
|
||
|
||
/* Iterate over each word in the bitset. */
|
||
EXECUTE_IF_SET_IN_SBITMAP (set, 0, i,
|
||
{
|
||
bitlst_table[bitlst_table_last++] = i;
|
||
(bl->nr_members)++;
|
||
});
|
||
|
||
}
|
||
|
||
/* Functions for the construction of regions. */
|
||
|
||
/* Print the regions, for debugging purposes. Callable from debugger. */
|
||
|
||
void
|
||
debug_regions ()
|
||
{
|
||
int rgn, bb;
|
||
|
||
fprintf (sched_dump, "\n;; ------------ REGIONS ----------\n\n");
|
||
for (rgn = 0; rgn < nr_regions; rgn++)
|
||
{
|
||
fprintf (sched_dump, ";;\trgn %d nr_blocks %d:\n", rgn,
|
||
rgn_table[rgn].rgn_nr_blocks);
|
||
fprintf (sched_dump, ";;\tbb/block: ");
|
||
|
||
for (bb = 0; bb < rgn_table[rgn].rgn_nr_blocks; bb++)
|
||
{
|
||
current_blocks = RGN_BLOCKS (rgn);
|
||
|
||
if (bb != BLOCK_TO_BB (BB_TO_BLOCK (bb)))
|
||
abort ();
|
||
|
||
fprintf (sched_dump, " %d/%d ", bb, BB_TO_BLOCK (bb));
|
||
}
|
||
|
||
fprintf (sched_dump, "\n\n");
|
||
}
|
||
}
|
||
|
||
/* Build a single block region for each basic block in the function.
|
||
This allows for using the same code for interblock and basic block
|
||
scheduling. */
|
||
|
||
static void
|
||
find_single_block_region ()
|
||
{
|
||
basic_block bb;
|
||
|
||
nr_regions = 0;
|
||
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
rgn_bb_table[nr_regions] = bb->index;
|
||
RGN_NR_BLOCKS (nr_regions) = 1;
|
||
RGN_BLOCKS (nr_regions) = nr_regions;
|
||
CONTAINING_RGN (bb->index) = nr_regions;
|
||
BLOCK_TO_BB (bb->index) = 0;
|
||
nr_regions++;
|
||
}
|
||
}
|
||
|
||
/* Update number of blocks and the estimate for number of insns
|
||
in the region. Return 1 if the region is "too large" for interblock
|
||
scheduling (compile time considerations), otherwise return 0. */
|
||
|
||
static int
|
||
too_large (block, num_bbs, num_insns)
|
||
int block, *num_bbs, *num_insns;
|
||
{
|
||
(*num_bbs)++;
|
||
(*num_insns) += (INSN_LUID (BLOCK_END (block)) -
|
||
INSN_LUID (BLOCK_HEAD (block)));
|
||
if ((*num_bbs > MAX_RGN_BLOCKS) || (*num_insns > MAX_RGN_INSNS))
|
||
return 1;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* Update_loop_relations(blk, hdr): Check if the loop headed by max_hdr[blk]
|
||
is still an inner loop. Put in max_hdr[blk] the header of the most inner
|
||
loop containing blk. */
|
||
#define UPDATE_LOOP_RELATIONS(blk, hdr) \
|
||
{ \
|
||
if (max_hdr[blk] == -1) \
|
||
max_hdr[blk] = hdr; \
|
||
else if (dfs_nr[max_hdr[blk]] > dfs_nr[hdr]) \
|
||
RESET_BIT (inner, hdr); \
|
||
else if (dfs_nr[max_hdr[blk]] < dfs_nr[hdr]) \
|
||
{ \
|
||
RESET_BIT (inner,max_hdr[blk]); \
|
||
max_hdr[blk] = hdr; \
|
||
} \
|
||
}
|
||
|
||
/* Find regions for interblock scheduling.
|
||
|
||
A region for scheduling can be:
|
||
|
||
* A loop-free procedure, or
|
||
|
||
* A reducible inner loop, or
|
||
|
||
* A basic block not contained in any other region.
|
||
|
||
?!? In theory we could build other regions based on extended basic
|
||
blocks or reverse extended basic blocks. Is it worth the trouble?
|
||
|
||
Loop blocks that form a region are put into the region's block list
|
||
in topological order.
|
||
|
||
This procedure stores its results into the following global (ick) variables
|
||
|
||
* rgn_nr
|
||
* rgn_table
|
||
* rgn_bb_table
|
||
* block_to_bb
|
||
* containing region
|
||
|
||
We use dominator relationships to avoid making regions out of non-reducible
|
||
loops.
|
||
|
||
This procedure needs to be converted to work on pred/succ lists instead
|
||
of edge tables. That would simplify it somewhat. */
|
||
|
||
static void
|
||
find_rgns (edge_list, dom)
|
||
struct edge_list *edge_list;
|
||
dominance_info dom;
|
||
{
|
||
int *max_hdr, *dfs_nr, *stack, *degree;
|
||
char no_loops = 1;
|
||
int node, child, loop_head, i, head, tail;
|
||
int count = 0, sp, idx = 0, current_edge = out_edges[0];
|
||
int num_bbs, num_insns, unreachable;
|
||
int too_large_failure;
|
||
basic_block bb;
|
||
|
||
/* Note if an edge has been passed. */
|
||
sbitmap passed;
|
||
|
||
/* Note if a block is a natural loop header. */
|
||
sbitmap header;
|
||
|
||
/* Note if a block is a natural inner loop header. */
|
||
sbitmap inner;
|
||
|
||
/* Note if a block is in the block queue. */
|
||
sbitmap in_queue;
|
||
|
||
/* Note if a block is in the block queue. */
|
||
sbitmap in_stack;
|
||
|
||
int num_edges = NUM_EDGES (edge_list);
|
||
|
||
/* Perform a DFS traversal of the cfg. Identify loop headers, inner loops
|
||
and a mapping from block to its loop header (if the block is contained
|
||
in a loop, else -1).
|
||
|
||
Store results in HEADER, INNER, and MAX_HDR respectively, these will
|
||
be used as inputs to the second traversal.
|
||
|
||
STACK, SP and DFS_NR are only used during the first traversal. */
|
||
|
||
/* Allocate and initialize variables for the first traversal. */
|
||
max_hdr = (int *) xmalloc (last_basic_block * sizeof (int));
|
||
dfs_nr = (int *) xcalloc (last_basic_block, sizeof (int));
|
||
stack = (int *) xmalloc (nr_edges * sizeof (int));
|
||
|
||
inner = sbitmap_alloc (last_basic_block);
|
||
sbitmap_ones (inner);
|
||
|
||
header = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (header);
|
||
|
||
passed = sbitmap_alloc (nr_edges);
|
||
sbitmap_zero (passed);
|
||
|
||
in_queue = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (in_queue);
|
||
|
||
in_stack = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (in_stack);
|
||
|
||
for (i = 0; i < last_basic_block; i++)
|
||
max_hdr[i] = -1;
|
||
|
||
/* DFS traversal to find inner loops in the cfg. */
|
||
|
||
sp = -1;
|
||
while (1)
|
||
{
|
||
if (current_edge == 0 || TEST_BIT (passed, current_edge))
|
||
{
|
||
/* We have reached a leaf node or a node that was already
|
||
processed. Pop edges off the stack until we find
|
||
an edge that has not yet been processed. */
|
||
while (sp >= 0
|
||
&& (current_edge == 0 || TEST_BIT (passed, current_edge)))
|
||
{
|
||
/* Pop entry off the stack. */
|
||
current_edge = stack[sp--];
|
||
node = FROM_BLOCK (current_edge);
|
||
child = TO_BLOCK (current_edge);
|
||
RESET_BIT (in_stack, child);
|
||
if (max_hdr[child] >= 0 && TEST_BIT (in_stack, max_hdr[child]))
|
||
UPDATE_LOOP_RELATIONS (node, max_hdr[child]);
|
||
current_edge = NEXT_OUT (current_edge);
|
||
}
|
||
|
||
/* See if have finished the DFS tree traversal. */
|
||
if (sp < 0 && TEST_BIT (passed, current_edge))
|
||
break;
|
||
|
||
/* Nope, continue the traversal with the popped node. */
|
||
continue;
|
||
}
|
||
|
||
/* Process a node. */
|
||
node = FROM_BLOCK (current_edge);
|
||
child = TO_BLOCK (current_edge);
|
||
SET_BIT (in_stack, node);
|
||
dfs_nr[node] = ++count;
|
||
|
||
/* If the successor is in the stack, then we've found a loop.
|
||
Mark the loop, if it is not a natural loop, then it will
|
||
be rejected during the second traversal. */
|
||
if (TEST_BIT (in_stack, child))
|
||
{
|
||
no_loops = 0;
|
||
SET_BIT (header, child);
|
||
UPDATE_LOOP_RELATIONS (node, child);
|
||
SET_BIT (passed, current_edge);
|
||
current_edge = NEXT_OUT (current_edge);
|
||
continue;
|
||
}
|
||
|
||
/* If the child was already visited, then there is no need to visit
|
||
it again. Just update the loop relationships and restart
|
||
with a new edge. */
|
||
if (dfs_nr[child])
|
||
{
|
||
if (max_hdr[child] >= 0 && TEST_BIT (in_stack, max_hdr[child]))
|
||
UPDATE_LOOP_RELATIONS (node, max_hdr[child]);
|
||
SET_BIT (passed, current_edge);
|
||
current_edge = NEXT_OUT (current_edge);
|
||
continue;
|
||
}
|
||
|
||
/* Push an entry on the stack and continue DFS traversal. */
|
||
stack[++sp] = current_edge;
|
||
SET_BIT (passed, current_edge);
|
||
current_edge = OUT_EDGES (child);
|
||
|
||
/* This is temporary until haifa is converted to use rth's new
|
||
cfg routines which have true entry/exit blocks and the
|
||
appropriate edges from/to those blocks.
|
||
|
||
Generally we update dfs_nr for a node when we process its
|
||
out edge. However, if the node has no out edge then we will
|
||
not set dfs_nr for that node. This can confuse the scheduler
|
||
into thinking that we have unreachable blocks, which in turn
|
||
disables cross block scheduling.
|
||
|
||
So, if we have a node with no out edges, go ahead and mark it
|
||
as reachable now. */
|
||
if (current_edge == 0)
|
||
dfs_nr[child] = ++count;
|
||
}
|
||
|
||
/* Another check for unreachable blocks. The earlier test in
|
||
is_cfg_nonregular only finds unreachable blocks that do not
|
||
form a loop.
|
||
|
||
The DFS traversal will mark every block that is reachable from
|
||
the entry node by placing a nonzero value in dfs_nr. Thus if
|
||
dfs_nr is zero for any block, then it must be unreachable. */
|
||
unreachable = 0;
|
||
FOR_EACH_BB (bb)
|
||
if (dfs_nr[bb->index] == 0)
|
||
{
|
||
unreachable = 1;
|
||
break;
|
||
}
|
||
|
||
/* Gross. To avoid wasting memory, the second pass uses the dfs_nr array
|
||
to hold degree counts. */
|
||
degree = dfs_nr;
|
||
|
||
FOR_EACH_BB (bb)
|
||
degree[bb->index] = 0;
|
||
for (i = 0; i < num_edges; i++)
|
||
{
|
||
edge e = INDEX_EDGE (edge_list, i);
|
||
|
||
if (e->dest != EXIT_BLOCK_PTR)
|
||
degree[e->dest->index]++;
|
||
}
|
||
|
||
/* Do not perform region scheduling if there are any unreachable
|
||
blocks. */
|
||
if (!unreachable)
|
||
{
|
||
int *queue;
|
||
|
||
if (no_loops)
|
||
SET_BIT (header, 0);
|
||
|
||
/* Second travsersal:find reducible inner loops and topologically sort
|
||
block of each region. */
|
||
|
||
queue = (int *) xmalloc (n_basic_blocks * sizeof (int));
|
||
|
||
/* Find blocks which are inner loop headers. We still have non-reducible
|
||
loops to consider at this point. */
|
||
FOR_EACH_BB (bb)
|
||
{
|
||
if (TEST_BIT (header, bb->index) && TEST_BIT (inner, bb->index))
|
||
{
|
||
edge e;
|
||
basic_block jbb;
|
||
|
||
/* Now check that the loop is reducible. We do this separate
|
||
from finding inner loops so that we do not find a reducible
|
||
loop which contains an inner non-reducible loop.
|
||
|
||
A simple way to find reducible/natural loops is to verify
|
||
that each block in the loop is dominated by the loop
|
||
header.
|
||
|
||
If there exists a block that is not dominated by the loop
|
||
header, then the block is reachable from outside the loop
|
||
and thus the loop is not a natural loop. */
|
||
FOR_EACH_BB (jbb)
|
||
{
|
||
/* First identify blocks in the loop, except for the loop
|
||
entry block. */
|
||
if (bb->index == max_hdr[jbb->index] && bb != jbb)
|
||
{
|
||
/* Now verify that the block is dominated by the loop
|
||
header. */
|
||
if (!dominated_by_p (dom, jbb, bb))
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* If we exited the loop early, then I is the header of
|
||
a non-reducible loop and we should quit processing it
|
||
now. */
|
||
if (jbb != EXIT_BLOCK_PTR)
|
||
continue;
|
||
|
||
/* I is a header of an inner loop, or block 0 in a subroutine
|
||
with no loops at all. */
|
||
head = tail = -1;
|
||
too_large_failure = 0;
|
||
loop_head = max_hdr[bb->index];
|
||
|
||
/* Decrease degree of all I's successors for topological
|
||
ordering. */
|
||
for (e = bb->succ; e; e = e->succ_next)
|
||
if (e->dest != EXIT_BLOCK_PTR)
|
||
--degree[e->dest->index];
|
||
|
||
/* Estimate # insns, and count # blocks in the region. */
|
||
num_bbs = 1;
|
||
num_insns = (INSN_LUID (bb->end)
|
||
- INSN_LUID (bb->head));
|
||
|
||
/* Find all loop latches (blocks with back edges to the loop
|
||
header) or all the leaf blocks in the cfg has no loops.
|
||
|
||
Place those blocks into the queue. */
|
||
if (no_loops)
|
||
{
|
||
FOR_EACH_BB (jbb)
|
||
/* Leaf nodes have only a single successor which must
|
||
be EXIT_BLOCK. */
|
||
if (jbb->succ
|
||
&& jbb->succ->dest == EXIT_BLOCK_PTR
|
||
&& jbb->succ->succ_next == NULL)
|
||
{
|
||
queue[++tail] = jbb->index;
|
||
SET_BIT (in_queue, jbb->index);
|
||
|
||
if (too_large (jbb->index, &num_bbs, &num_insns))
|
||
{
|
||
too_large_failure = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
edge e;
|
||
|
||
for (e = bb->pred; e; e = e->pred_next)
|
||
{
|
||
if (e->src == ENTRY_BLOCK_PTR)
|
||
continue;
|
||
|
||
node = e->src->index;
|
||
|
||
if (max_hdr[node] == loop_head && node != bb->index)
|
||
{
|
||
/* This is a loop latch. */
|
||
queue[++tail] = node;
|
||
SET_BIT (in_queue, node);
|
||
|
||
if (too_large (node, &num_bbs, &num_insns))
|
||
{
|
||
too_large_failure = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Now add all the blocks in the loop to the queue.
|
||
|
||
We know the loop is a natural loop; however the algorithm
|
||
above will not always mark certain blocks as being in the
|
||
loop. Consider:
|
||
node children
|
||
a b,c
|
||
b c
|
||
c a,d
|
||
d b
|
||
|
||
The algorithm in the DFS traversal may not mark B & D as part
|
||
of the loop (ie they will not have max_hdr set to A).
|
||
|
||
We know they can not be loop latches (else they would have
|
||
had max_hdr set since they'd have a backedge to a dominator
|
||
block). So we don't need them on the initial queue.
|
||
|
||
We know they are part of the loop because they are dominated
|
||
by the loop header and can be reached by a backwards walk of
|
||
the edges starting with nodes on the initial queue.
|
||
|
||
It is safe and desirable to include those nodes in the
|
||
loop/scheduling region. To do so we would need to decrease
|
||
the degree of a node if it is the target of a backedge
|
||
within the loop itself as the node is placed in the queue.
|
||
|
||
We do not do this because I'm not sure that the actual
|
||
scheduling code will properly handle this case. ?!? */
|
||
|
||
while (head < tail && !too_large_failure)
|
||
{
|
||
edge e;
|
||
child = queue[++head];
|
||
|
||
for (e = BASIC_BLOCK (child)->pred; e; e = e->pred_next)
|
||
{
|
||
node = e->src->index;
|
||
|
||
/* See discussion above about nodes not marked as in
|
||
this loop during the initial DFS traversal. */
|
||
if (e->src == ENTRY_BLOCK_PTR
|
||
|| max_hdr[node] != loop_head)
|
||
{
|
||
tail = -1;
|
||
break;
|
||
}
|
||
else if (!TEST_BIT (in_queue, node) && node != bb->index)
|
||
{
|
||
queue[++tail] = node;
|
||
SET_BIT (in_queue, node);
|
||
|
||
if (too_large (node, &num_bbs, &num_insns))
|
||
{
|
||
too_large_failure = 1;
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
if (tail >= 0 && !too_large_failure)
|
||
{
|
||
/* Place the loop header into list of region blocks. */
|
||
degree[bb->index] = -1;
|
||
rgn_bb_table[idx] = bb->index;
|
||
RGN_NR_BLOCKS (nr_regions) = num_bbs;
|
||
RGN_BLOCKS (nr_regions) = idx++;
|
||
CONTAINING_RGN (bb->index) = nr_regions;
|
||
BLOCK_TO_BB (bb->index) = count = 0;
|
||
|
||
/* Remove blocks from queue[] when their in degree
|
||
becomes zero. Repeat until no blocks are left on the
|
||
list. This produces a topological list of blocks in
|
||
the region. */
|
||
while (tail >= 0)
|
||
{
|
||
if (head < 0)
|
||
head = tail;
|
||
child = queue[head];
|
||
if (degree[child] == 0)
|
||
{
|
||
edge e;
|
||
|
||
degree[child] = -1;
|
||
rgn_bb_table[idx++] = child;
|
||
BLOCK_TO_BB (child) = ++count;
|
||
CONTAINING_RGN (child) = nr_regions;
|
||
queue[head] = queue[tail--];
|
||
|
||
for (e = BASIC_BLOCK (child)->succ;
|
||
e;
|
||
e = e->succ_next)
|
||
if (e->dest != EXIT_BLOCK_PTR)
|
||
--degree[e->dest->index];
|
||
}
|
||
else
|
||
--head;
|
||
}
|
||
++nr_regions;
|
||
}
|
||
}
|
||
}
|
||
free (queue);
|
||
}
|
||
|
||
/* Any block that did not end up in a region is placed into a region
|
||
by itself. */
|
||
FOR_EACH_BB (bb)
|
||
if (degree[bb->index] >= 0)
|
||
{
|
||
rgn_bb_table[idx] = bb->index;
|
||
RGN_NR_BLOCKS (nr_regions) = 1;
|
||
RGN_BLOCKS (nr_regions) = idx++;
|
||
CONTAINING_RGN (bb->index) = nr_regions++;
|
||
BLOCK_TO_BB (bb->index) = 0;
|
||
}
|
||
|
||
free (max_hdr);
|
||
free (dfs_nr);
|
||
free (stack);
|
||
sbitmap_free (passed);
|
||
sbitmap_free (header);
|
||
sbitmap_free (inner);
|
||
sbitmap_free (in_queue);
|
||
sbitmap_free (in_stack);
|
||
}
|
||
|
||
/* Functions for regions scheduling information. */
|
||
|
||
/* Compute dominators, probability, and potential-split-edges of bb.
|
||
Assume that these values were already computed for bb's predecessors. */
|
||
|
||
static void
|
||
compute_dom_prob_ps (bb)
|
||
int bb;
|
||
{
|
||
int nxt_in_edge, fst_in_edge, pred;
|
||
int fst_out_edge, nxt_out_edge, nr_out_edges, nr_rgn_out_edges;
|
||
|
||
prob[bb] = 0.0;
|
||
if (IS_RGN_ENTRY (bb))
|
||
{
|
||
SET_BIT (dom[bb], 0);
|
||
prob[bb] = 1.0;
|
||
return;
|
||
}
|
||
|
||
fst_in_edge = nxt_in_edge = IN_EDGES (BB_TO_BLOCK (bb));
|
||
|
||
/* Initialize dom[bb] to '111..1'. */
|
||
sbitmap_ones (dom[bb]);
|
||
|
||
do
|
||
{
|
||
pred = FROM_BLOCK (nxt_in_edge);
|
||
sbitmap_a_and_b (dom[bb], dom[bb], dom[BLOCK_TO_BB (pred)]);
|
||
sbitmap_a_or_b (ancestor_edges[bb], ancestor_edges[bb], ancestor_edges[BLOCK_TO_BB (pred)]);
|
||
|
||
SET_BIT (ancestor_edges[bb], EDGE_TO_BIT (nxt_in_edge));
|
||
|
||
nr_out_edges = 1;
|
||
nr_rgn_out_edges = 0;
|
||
fst_out_edge = OUT_EDGES (pred);
|
||
nxt_out_edge = NEXT_OUT (fst_out_edge);
|
||
|
||
sbitmap_a_or_b (pot_split[bb], pot_split[bb], pot_split[BLOCK_TO_BB (pred)]);
|
||
|
||
SET_BIT (pot_split[bb], EDGE_TO_BIT (fst_out_edge));
|
||
|
||
/* The successor doesn't belong in the region? */
|
||
if (CONTAINING_RGN (TO_BLOCK (fst_out_edge)) !=
|
||
CONTAINING_RGN (BB_TO_BLOCK (bb)))
|
||
++nr_rgn_out_edges;
|
||
|
||
while (fst_out_edge != nxt_out_edge)
|
||
{
|
||
++nr_out_edges;
|
||
/* The successor doesn't belong in the region? */
|
||
if (CONTAINING_RGN (TO_BLOCK (nxt_out_edge)) !=
|
||
CONTAINING_RGN (BB_TO_BLOCK (bb)))
|
||
++nr_rgn_out_edges;
|
||
SET_BIT (pot_split[bb], EDGE_TO_BIT (nxt_out_edge));
|
||
nxt_out_edge = NEXT_OUT (nxt_out_edge);
|
||
|
||
}
|
||
|
||
/* Now nr_rgn_out_edges is the number of region-exit edges from
|
||
pred, and nr_out_edges will be the number of pred out edges
|
||
not leaving the region. */
|
||
nr_out_edges -= nr_rgn_out_edges;
|
||
if (nr_rgn_out_edges > 0)
|
||
prob[bb] += 0.9 * prob[BLOCK_TO_BB (pred)] / nr_out_edges;
|
||
else
|
||
prob[bb] += prob[BLOCK_TO_BB (pred)] / nr_out_edges;
|
||
nxt_in_edge = NEXT_IN (nxt_in_edge);
|
||
}
|
||
while (fst_in_edge != nxt_in_edge);
|
||
|
||
SET_BIT (dom[bb], bb);
|
||
sbitmap_difference (pot_split[bb], pot_split[bb], ancestor_edges[bb]);
|
||
|
||
if (sched_verbose >= 2)
|
||
fprintf (sched_dump, ";; bb_prob(%d, %d) = %3d\n", bb, BB_TO_BLOCK (bb),
|
||
(int) (100.0 * prob[bb]));
|
||
}
|
||
|
||
/* Functions for target info. */
|
||
|
||
/* Compute in BL the list of split-edges of bb_src relatively to bb_trg.
|
||
Note that bb_trg dominates bb_src. */
|
||
|
||
static void
|
||
split_edges (bb_src, bb_trg, bl)
|
||
int bb_src;
|
||
int bb_trg;
|
||
edgelst *bl;
|
||
{
|
||
sbitmap src = (edgeset) sbitmap_alloc (pot_split[bb_src]->n_bits);
|
||
sbitmap_copy (src, pot_split[bb_src]);
|
||
|
||
sbitmap_difference (src, src, pot_split[bb_trg]);
|
||
extract_bitlst (src, bl);
|
||
sbitmap_free (src);
|
||
}
|
||
|
||
/* Find the valid candidate-source-blocks for the target block TRG, compute
|
||
their probability, and check if they are speculative or not.
|
||
For speculative sources, compute their update-blocks and split-blocks. */
|
||
|
||
static void
|
||
compute_trg_info (trg)
|
||
int trg;
|
||
{
|
||
candidate *sp;
|
||
edgelst el;
|
||
int check_block, update_idx;
|
||
int i, j, k, fst_edge, nxt_edge;
|
||
|
||
/* Define some of the fields for the target bb as well. */
|
||
sp = candidate_table + trg;
|
||
sp->is_valid = 1;
|
||
sp->is_speculative = 0;
|
||
sp->src_prob = 100;
|
||
|
||
for (i = trg + 1; i < current_nr_blocks; i++)
|
||
{
|
||
sp = candidate_table + i;
|
||
|
||
sp->is_valid = IS_DOMINATED (i, trg);
|
||
if (sp->is_valid)
|
||
{
|
||
sp->src_prob = GET_SRC_PROB (i, trg);
|
||
sp->is_valid = (sp->src_prob >= MIN_PROBABILITY);
|
||
}
|
||
|
||
if (sp->is_valid)
|
||
{
|
||
split_edges (i, trg, &el);
|
||
sp->is_speculative = (el.nr_members) ? 1 : 0;
|
||
if (sp->is_speculative && !flag_schedule_speculative)
|
||
sp->is_valid = 0;
|
||
}
|
||
|
||
if (sp->is_valid)
|
||
{
|
||
char *update_blocks;
|
||
|
||
/* Compute split blocks and store them in bblst_table.
|
||
The TO block of every split edge is a split block. */
|
||
sp->split_bbs.first_member = &bblst_table[bblst_last];
|
||
sp->split_bbs.nr_members = el.nr_members;
|
||
for (j = 0; j < el.nr_members; bblst_last++, j++)
|
||
bblst_table[bblst_last] =
|
||
TO_BLOCK (rgn_edges[el.first_member[j]]);
|
||
sp->update_bbs.first_member = &bblst_table[bblst_last];
|
||
|
||
/* Compute update blocks and store them in bblst_table.
|
||
For every split edge, look at the FROM block, and check
|
||
all out edges. For each out edge that is not a split edge,
|
||
add the TO block to the update block list. This list can end
|
||
up with a lot of duplicates. We need to weed them out to avoid
|
||
overrunning the end of the bblst_table. */
|
||
update_blocks = (char *) alloca (last_basic_block);
|
||
memset (update_blocks, 0, last_basic_block);
|
||
|
||
update_idx = 0;
|
||
for (j = 0; j < el.nr_members; j++)
|
||
{
|
||
check_block = FROM_BLOCK (rgn_edges[el.first_member[j]]);
|
||
fst_edge = nxt_edge = OUT_EDGES (check_block);
|
||
do
|
||
{
|
||
if (! update_blocks[TO_BLOCK (nxt_edge)])
|
||
{
|
||
for (k = 0; k < el.nr_members; k++)
|
||
if (EDGE_TO_BIT (nxt_edge) == el.first_member[k])
|
||
break;
|
||
|
||
if (k >= el.nr_members)
|
||
{
|
||
bblst_table[bblst_last++] = TO_BLOCK (nxt_edge);
|
||
update_blocks[TO_BLOCK (nxt_edge)] = 1;
|
||
update_idx++;
|
||
}
|
||
}
|
||
|
||
nxt_edge = NEXT_OUT (nxt_edge);
|
||
}
|
||
while (fst_edge != nxt_edge);
|
||
}
|
||
sp->update_bbs.nr_members = update_idx;
|
||
|
||
/* Make sure we didn't overrun the end of bblst_table. */
|
||
if (bblst_last > bblst_size)
|
||
abort ();
|
||
}
|
||
else
|
||
{
|
||
sp->split_bbs.nr_members = sp->update_bbs.nr_members = 0;
|
||
|
||
sp->is_speculative = 0;
|
||
sp->src_prob = 0;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Print candidates info, for debugging purposes. Callable from debugger. */
|
||
|
||
void
|
||
debug_candidate (i)
|
||
int i;
|
||
{
|
||
if (!candidate_table[i].is_valid)
|
||
return;
|
||
|
||
if (candidate_table[i].is_speculative)
|
||
{
|
||
int j;
|
||
fprintf (sched_dump, "src b %d bb %d speculative \n", BB_TO_BLOCK (i), i);
|
||
|
||
fprintf (sched_dump, "split path: ");
|
||
for (j = 0; j < candidate_table[i].split_bbs.nr_members; j++)
|
||
{
|
||
int b = candidate_table[i].split_bbs.first_member[j];
|
||
|
||
fprintf (sched_dump, " %d ", b);
|
||
}
|
||
fprintf (sched_dump, "\n");
|
||
|
||
fprintf (sched_dump, "update path: ");
|
||
for (j = 0; j < candidate_table[i].update_bbs.nr_members; j++)
|
||
{
|
||
int b = candidate_table[i].update_bbs.first_member[j];
|
||
|
||
fprintf (sched_dump, " %d ", b);
|
||
}
|
||
fprintf (sched_dump, "\n");
|
||
}
|
||
else
|
||
{
|
||
fprintf (sched_dump, " src %d equivalent\n", BB_TO_BLOCK (i));
|
||
}
|
||
}
|
||
|
||
/* Print candidates info, for debugging purposes. Callable from debugger. */
|
||
|
||
void
|
||
debug_candidates (trg)
|
||
int trg;
|
||
{
|
||
int i;
|
||
|
||
fprintf (sched_dump, "----------- candidate table: target: b=%d bb=%d ---\n",
|
||
BB_TO_BLOCK (trg), trg);
|
||
for (i = trg + 1; i < current_nr_blocks; i++)
|
||
debug_candidate (i);
|
||
}
|
||
|
||
/* Functions for speculative scheduing. */
|
||
|
||
/* Return 0 if x is a set of a register alive in the beginning of one
|
||
of the split-blocks of src, otherwise return 1. */
|
||
|
||
static int
|
||
check_live_1 (src, x)
|
||
int src;
|
||
rtx x;
|
||
{
|
||
int i;
|
||
int regno;
|
||
rtx reg = SET_DEST (x);
|
||
|
||
if (reg == 0)
|
||
return 1;
|
||
|
||
while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT
|
||
|| GET_CODE (reg) == SIGN_EXTRACT
|
||
|| GET_CODE (reg) == STRICT_LOW_PART)
|
||
reg = XEXP (reg, 0);
|
||
|
||
if (GET_CODE (reg) == PARALLEL)
|
||
{
|
||
int i;
|
||
|
||
for (i = XVECLEN (reg, 0) - 1; i >= 0; i--)
|
||
if (XEXP (XVECEXP (reg, 0, i), 0) != 0)
|
||
if (check_live_1 (src, XEXP (XVECEXP (reg, 0, i), 0)))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
if (GET_CODE (reg) != REG)
|
||
return 1;
|
||
|
||
regno = REGNO (reg);
|
||
|
||
if (regno < FIRST_PSEUDO_REGISTER && global_regs[regno])
|
||
{
|
||
/* Global registers are assumed live. */
|
||
return 0;
|
||
}
|
||
else
|
||
{
|
||
if (regno < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
/* Check for hard registers. */
|
||
int j = HARD_REGNO_NREGS (regno, GET_MODE (reg));
|
||
while (--j >= 0)
|
||
{
|
||
for (i = 0; i < candidate_table[src].split_bbs.nr_members; i++)
|
||
{
|
||
int b = candidate_table[src].split_bbs.first_member[i];
|
||
|
||
if (REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start,
|
||
regno + j))
|
||
{
|
||
return 0;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Check for psuedo registers. */
|
||
for (i = 0; i < candidate_table[src].split_bbs.nr_members; i++)
|
||
{
|
||
int b = candidate_table[src].split_bbs.first_member[i];
|
||
|
||
if (REGNO_REG_SET_P (BASIC_BLOCK (b)->global_live_at_start, regno))
|
||
{
|
||
return 0;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* If x is a set of a register R, mark that R is alive in the beginning
|
||
of every update-block of src. */
|
||
|
||
static void
|
||
update_live_1 (src, x)
|
||
int src;
|
||
rtx x;
|
||
{
|
||
int i;
|
||
int regno;
|
||
rtx reg = SET_DEST (x);
|
||
|
||
if (reg == 0)
|
||
return;
|
||
|
||
while (GET_CODE (reg) == SUBREG || GET_CODE (reg) == ZERO_EXTRACT
|
||
|| GET_CODE (reg) == SIGN_EXTRACT
|
||
|| GET_CODE (reg) == STRICT_LOW_PART)
|
||
reg = XEXP (reg, 0);
|
||
|
||
if (GET_CODE (reg) == PARALLEL)
|
||
{
|
||
int i;
|
||
|
||
for (i = XVECLEN (reg, 0) - 1; i >= 0; i--)
|
||
if (XEXP (XVECEXP (reg, 0, i), 0) != 0)
|
||
update_live_1 (src, XEXP (XVECEXP (reg, 0, i), 0));
|
||
|
||
return;
|
||
}
|
||
|
||
if (GET_CODE (reg) != REG)
|
||
return;
|
||
|
||
/* Global registers are always live, so the code below does not apply
|
||
to them. */
|
||
|
||
regno = REGNO (reg);
|
||
|
||
if (regno >= FIRST_PSEUDO_REGISTER || !global_regs[regno])
|
||
{
|
||
if (regno < FIRST_PSEUDO_REGISTER)
|
||
{
|
||
int j = HARD_REGNO_NREGS (regno, GET_MODE (reg));
|
||
while (--j >= 0)
|
||
{
|
||
for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++)
|
||
{
|
||
int b = candidate_table[src].update_bbs.first_member[i];
|
||
|
||
SET_REGNO_REG_SET (BASIC_BLOCK (b)->global_live_at_start,
|
||
regno + j);
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
for (i = 0; i < candidate_table[src].update_bbs.nr_members; i++)
|
||
{
|
||
int b = candidate_table[src].update_bbs.first_member[i];
|
||
|
||
SET_REGNO_REG_SET (BASIC_BLOCK (b)->global_live_at_start, regno);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return 1 if insn can be speculatively moved from block src to trg,
|
||
otherwise return 0. Called before first insertion of insn to
|
||
ready-list or before the scheduling. */
|
||
|
||
static int
|
||
check_live (insn, src)
|
||
rtx insn;
|
||
int src;
|
||
{
|
||
/* Find the registers set by instruction. */
|
||
if (GET_CODE (PATTERN (insn)) == SET
|
||
|| GET_CODE (PATTERN (insn)) == CLOBBER)
|
||
return check_live_1 (src, PATTERN (insn));
|
||
else if (GET_CODE (PATTERN (insn)) == PARALLEL)
|
||
{
|
||
int j;
|
||
for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--)
|
||
if ((GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET
|
||
|| GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER)
|
||
&& !check_live_1 (src, XVECEXP (PATTERN (insn), 0, j)))
|
||
return 0;
|
||
|
||
return 1;
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Update the live registers info after insn was moved speculatively from
|
||
block src to trg. */
|
||
|
||
static void
|
||
update_live (insn, src)
|
||
rtx insn;
|
||
int src;
|
||
{
|
||
/* Find the registers set by instruction. */
|
||
if (GET_CODE (PATTERN (insn)) == SET
|
||
|| GET_CODE (PATTERN (insn)) == CLOBBER)
|
||
update_live_1 (src, PATTERN (insn));
|
||
else if (GET_CODE (PATTERN (insn)) == PARALLEL)
|
||
{
|
||
int j;
|
||
for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--)
|
||
if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET
|
||
|| GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == CLOBBER)
|
||
update_live_1 (src, XVECEXP (PATTERN (insn), 0, j));
|
||
}
|
||
}
|
||
|
||
/* Exception Free Loads:
|
||
|
||
We define five classes of speculative loads: IFREE, IRISKY,
|
||
PFREE, PRISKY, and MFREE.
|
||
|
||
IFREE loads are loads that are proved to be exception-free, just
|
||
by examining the load insn. Examples for such loads are loads
|
||
from TOC and loads of global data.
|
||
|
||
IRISKY loads are loads that are proved to be exception-risky,
|
||
just by examining the load insn. Examples for such loads are
|
||
volatile loads and loads from shared memory.
|
||
|
||
PFREE loads are loads for which we can prove, by examining other
|
||
insns, that they are exception-free. Currently, this class consists
|
||
of loads for which we are able to find a "similar load", either in
|
||
the target block, or, if only one split-block exists, in that split
|
||
block. Load2 is similar to load1 if both have same single base
|
||
register. We identify only part of the similar loads, by finding
|
||
an insn upon which both load1 and load2 have a DEF-USE dependence.
|
||
|
||
PRISKY loads are loads for which we can prove, by examining other
|
||
insns, that they are exception-risky. Currently we have two proofs for
|
||
such loads. The first proof detects loads that are probably guarded by a
|
||
test on the memory address. This proof is based on the
|
||
backward and forward data dependence information for the region.
|
||
Let load-insn be the examined load.
|
||
Load-insn is PRISKY iff ALL the following hold:
|
||
|
||
- insn1 is not in the same block as load-insn
|
||
- there is a DEF-USE dependence chain (insn1, ..., load-insn)
|
||
- test-insn is either a compare or a branch, not in the same block
|
||
as load-insn
|
||
- load-insn is reachable from test-insn
|
||
- there is a DEF-USE dependence chain (insn1, ..., test-insn)
|
||
|
||
This proof might fail when the compare and the load are fed
|
||
by an insn not in the region. To solve this, we will add to this
|
||
group all loads that have no input DEF-USE dependence.
|
||
|
||
The second proof detects loads that are directly or indirectly
|
||
fed by a speculative load. This proof is affected by the
|
||
scheduling process. We will use the flag fed_by_spec_load.
|
||
Initially, all insns have this flag reset. After a speculative
|
||
motion of an insn, if insn is either a load, or marked as
|
||
fed_by_spec_load, we will also mark as fed_by_spec_load every
|
||
insn1 for which a DEF-USE dependence (insn, insn1) exists. A
|
||
load which is fed_by_spec_load is also PRISKY.
|
||
|
||
MFREE (maybe-free) loads are all the remaining loads. They may be
|
||
exception-free, but we cannot prove it.
|
||
|
||
Now, all loads in IFREE and PFREE classes are considered
|
||
exception-free, while all loads in IRISKY and PRISKY classes are
|
||
considered exception-risky. As for loads in the MFREE class,
|
||
these are considered either exception-free or exception-risky,
|
||
depending on whether we are pessimistic or optimistic. We have
|
||
to take the pessimistic approach to assure the safety of
|
||
speculative scheduling, but we can take the optimistic approach
|
||
by invoking the -fsched_spec_load_dangerous option. */
|
||
|
||
enum INSN_TRAP_CLASS
|
||
{
|
||
TRAP_FREE = 0, IFREE = 1, PFREE_CANDIDATE = 2,
|
||
PRISKY_CANDIDATE = 3, IRISKY = 4, TRAP_RISKY = 5
|
||
};
|
||
|
||
#define WORST_CLASS(class1, class2) \
|
||
((class1 > class2) ? class1 : class2)
|
||
|
||
/* Non-zero if block bb_to is equal to, or reachable from block bb_from. */
|
||
#define IS_REACHABLE(bb_from, bb_to) \
|
||
(bb_from == bb_to \
|
||
|| IS_RGN_ENTRY (bb_from) \
|
||
|| (TEST_BIT (ancestor_edges[bb_to], \
|
||
EDGE_TO_BIT (IN_EDGES (BB_TO_BLOCK (bb_from))))))
|
||
|
||
/* Non-zero iff the address is comprised from at most 1 register. */
|
||
#define CONST_BASED_ADDRESS_P(x) \
|
||
(GET_CODE (x) == REG \
|
||
|| ((GET_CODE (x) == PLUS || GET_CODE (x) == MINUS \
|
||
|| (GET_CODE (x) == LO_SUM)) \
|
||
&& (CONSTANT_P (XEXP (x, 0)) \
|
||
|| CONSTANT_P (XEXP (x, 1)))))
|
||
|
||
/* Turns on the fed_by_spec_load flag for insns fed by load_insn. */
|
||
|
||
static void
|
||
set_spec_fed (load_insn)
|
||
rtx load_insn;
|
||
{
|
||
rtx link;
|
||
|
||
for (link = INSN_DEPEND (load_insn); link; link = XEXP (link, 1))
|
||
if (GET_MODE (link) == VOIDmode)
|
||
FED_BY_SPEC_LOAD (XEXP (link, 0)) = 1;
|
||
} /* set_spec_fed */
|
||
|
||
/* On the path from the insn to load_insn_bb, find a conditional
|
||
branch depending on insn, that guards the speculative load. */
|
||
|
||
static int
|
||
find_conditional_protection (insn, load_insn_bb)
|
||
rtx insn;
|
||
int load_insn_bb;
|
||
{
|
||
rtx link;
|
||
|
||
/* Iterate through DEF-USE forward dependences. */
|
||
for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1))
|
||
{
|
||
rtx next = XEXP (link, 0);
|
||
if ((CONTAINING_RGN (BLOCK_NUM (next)) ==
|
||
CONTAINING_RGN (BB_TO_BLOCK (load_insn_bb)))
|
||
&& IS_REACHABLE (INSN_BB (next), load_insn_bb)
|
||
&& load_insn_bb != INSN_BB (next)
|
||
&& GET_MODE (link) == VOIDmode
|
||
&& (GET_CODE (next) == JUMP_INSN
|
||
|| find_conditional_protection (next, load_insn_bb)))
|
||
return 1;
|
||
}
|
||
return 0;
|
||
} /* find_conditional_protection */
|
||
|
||
/* Returns 1 if the same insn1 that participates in the computation
|
||
of load_insn's address is feeding a conditional branch that is
|
||
guarding on load_insn. This is true if we find a the two DEF-USE
|
||
chains:
|
||
insn1 -> ... -> conditional-branch
|
||
insn1 -> ... -> load_insn,
|
||
and if a flow path exist:
|
||
insn1 -> ... -> conditional-branch -> ... -> load_insn,
|
||
and if insn1 is on the path
|
||
region-entry -> ... -> bb_trg -> ... load_insn.
|
||
|
||
Locate insn1 by climbing on LOG_LINKS from load_insn.
|
||
Locate the branch by following INSN_DEPEND from insn1. */
|
||
|
||
static int
|
||
is_conditionally_protected (load_insn, bb_src, bb_trg)
|
||
rtx load_insn;
|
||
int bb_src, bb_trg;
|
||
{
|
||
rtx link;
|
||
|
||
for (link = LOG_LINKS (load_insn); link; link = XEXP (link, 1))
|
||
{
|
||
rtx insn1 = XEXP (link, 0);
|
||
|
||
/* Must be a DEF-USE dependence upon non-branch. */
|
||
if (GET_MODE (link) != VOIDmode
|
||
|| GET_CODE (insn1) == JUMP_INSN)
|
||
continue;
|
||
|
||
/* Must exist a path: region-entry -> ... -> bb_trg -> ... load_insn. */
|
||
if (INSN_BB (insn1) == bb_src
|
||
|| (CONTAINING_RGN (BLOCK_NUM (insn1))
|
||
!= CONTAINING_RGN (BB_TO_BLOCK (bb_src)))
|
||
|| (!IS_REACHABLE (bb_trg, INSN_BB (insn1))
|
||
&& !IS_REACHABLE (INSN_BB (insn1), bb_trg)))
|
||
continue;
|
||
|
||
/* Now search for the conditional-branch. */
|
||
if (find_conditional_protection (insn1, bb_src))
|
||
return 1;
|
||
|
||
/* Recursive step: search another insn1, "above" current insn1. */
|
||
return is_conditionally_protected (insn1, bb_src, bb_trg);
|
||
}
|
||
|
||
/* The chain does not exist. */
|
||
return 0;
|
||
} /* is_conditionally_protected */
|
||
|
||
/* Returns 1 if a clue for "similar load" 'insn2' is found, and hence
|
||
load_insn can move speculatively from bb_src to bb_trg. All the
|
||
following must hold:
|
||
|
||
(1) both loads have 1 base register (PFREE_CANDIDATEs).
|
||
(2) load_insn and load1 have a def-use dependence upon
|
||
the same insn 'insn1'.
|
||
(3) either load2 is in bb_trg, or:
|
||
- there's only one split-block, and
|
||
- load1 is on the escape path, and
|
||
|
||
From all these we can conclude that the two loads access memory
|
||
addresses that differ at most by a constant, and hence if moving
|
||
load_insn would cause an exception, it would have been caused by
|
||
load2 anyhow. */
|
||
|
||
static int
|
||
is_pfree (load_insn, bb_src, bb_trg)
|
||
rtx load_insn;
|
||
int bb_src, bb_trg;
|
||
{
|
||
rtx back_link;
|
||
candidate *candp = candidate_table + bb_src;
|
||
|
||
if (candp->split_bbs.nr_members != 1)
|
||
/* Must have exactly one escape block. */
|
||
return 0;
|
||
|
||
for (back_link = LOG_LINKS (load_insn);
|
||
back_link; back_link = XEXP (back_link, 1))
|
||
{
|
||
rtx insn1 = XEXP (back_link, 0);
|
||
|
||
if (GET_MODE (back_link) == VOIDmode)
|
||
{
|
||
/* Found a DEF-USE dependence (insn1, load_insn). */
|
||
rtx fore_link;
|
||
|
||
for (fore_link = INSN_DEPEND (insn1);
|
||
fore_link; fore_link = XEXP (fore_link, 1))
|
||
{
|
||
rtx insn2 = XEXP (fore_link, 0);
|
||
if (GET_MODE (fore_link) == VOIDmode)
|
||
{
|
||
/* Found a DEF-USE dependence (insn1, insn2). */
|
||
if (haifa_classify_insn (insn2) != PFREE_CANDIDATE)
|
||
/* insn2 not guaranteed to be a 1 base reg load. */
|
||
continue;
|
||
|
||
if (INSN_BB (insn2) == bb_trg)
|
||
/* insn2 is the similar load, in the target block. */
|
||
return 1;
|
||
|
||
if (*(candp->split_bbs.first_member) == BLOCK_NUM (insn2))
|
||
/* insn2 is a similar load, in a split-block. */
|
||
return 1;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Couldn't find a similar load. */
|
||
return 0;
|
||
} /* is_pfree */
|
||
|
||
/* Returns a class that insn with GET_DEST(insn)=x may belong to,
|
||
as found by analyzing insn's expression. */
|
||
|
||
static int
|
||
may_trap_exp (x, is_store)
|
||
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 insn for the purpose of verifying that it can be
|
||
moved speculatively, by examining it's patterns, returning:
|
||
TRAP_RISKY: store, or risky non-load insn (e.g. division by variable).
|
||
TRAP_FREE: non-load insn.
|
||
IFREE: load from a globaly 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_insn (insn)
|
||
rtx insn;
|
||
{
|
||
rtx pat = PATTERN (insn);
|
||
int tmp_class = TRAP_FREE;
|
||
int insn_class = TRAP_FREE;
|
||
enum rtx_code code;
|
||
|
||
if (GET_CODE (pat) == PARALLEL)
|
||
{
|
||
int i, len = XVECLEN (pat, 0);
|
||
|
||
for (i = len - 1; i >= 0; i--)
|
||
{
|
||
code = GET_CODE (XVECEXP (pat, 0, i));
|
||
switch (code)
|
||
{
|
||
case CLOBBER:
|
||
/* Test if it is a 'store'. */
|
||
tmp_class = may_trap_exp (XEXP (XVECEXP (pat, 0, i), 0), 1);
|
||
break;
|
||
case SET:
|
||
/* Test if it is a store. */
|
||
tmp_class = may_trap_exp (SET_DEST (XVECEXP (pat, 0, i)), 1);
|
||
if (tmp_class == TRAP_RISKY)
|
||
break;
|
||
/* Test if it is a load. */
|
||
tmp_class
|
||
= WORST_CLASS (tmp_class,
|
||
may_trap_exp (SET_SRC (XVECEXP (pat, 0, i)),
|
||
0));
|
||
break;
|
||
case COND_EXEC:
|
||
case TRAP_IF:
|
||
tmp_class = TRAP_RISKY;
|
||
break;
|
||
default:
|
||
;
|
||
}
|
||
insn_class = WORST_CLASS (insn_class, tmp_class);
|
||
if (insn_class == TRAP_RISKY || insn_class == IRISKY)
|
||
break;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
code = GET_CODE (pat);
|
||
switch (code)
|
||
{
|
||
case CLOBBER:
|
||
/* Test if it is a 'store'. */
|
||
tmp_class = may_trap_exp (XEXP (pat, 0), 1);
|
||
break;
|
||
case SET:
|
||
/* Test if it is a store. */
|
||
tmp_class = may_trap_exp (SET_DEST (pat), 1);
|
||
if (tmp_class == TRAP_RISKY)
|
||
break;
|
||
/* Test if it is a load. */
|
||
tmp_class =
|
||
WORST_CLASS (tmp_class,
|
||
may_trap_exp (SET_SRC (pat), 0));
|
||
break;
|
||
case COND_EXEC:
|
||
case TRAP_IF:
|
||
tmp_class = TRAP_RISKY;
|
||
break;
|
||
default:;
|
||
}
|
||
insn_class = tmp_class;
|
||
}
|
||
|
||
return insn_class;
|
||
}
|
||
|
||
/* Return 1 if load_insn is prisky (i.e. if load_insn is fed by
|
||
a load moved speculatively, or if load_insn is protected by
|
||
a compare on load_insn's address). */
|
||
|
||
static int
|
||
is_prisky (load_insn, bb_src, bb_trg)
|
||
rtx load_insn;
|
||
int bb_src, bb_trg;
|
||
{
|
||
if (FED_BY_SPEC_LOAD (load_insn))
|
||
return 1;
|
||
|
||
if (LOG_LINKS (load_insn) == NULL)
|
||
/* Dependence may 'hide' out of the region. */
|
||
return 1;
|
||
|
||
if (is_conditionally_protected (load_insn, bb_src, bb_trg))
|
||
return 1;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Insn is a candidate to be moved speculatively from bb_src to bb_trg.
|
||
Return 1 if insn is exception-free (and the motion is valid)
|
||
and 0 otherwise. */
|
||
|
||
static int
|
||
is_exception_free (insn, bb_src, bb_trg)
|
||
rtx insn;
|
||
int bb_src, bb_trg;
|
||
{
|
||
int insn_class = haifa_classify_insn (insn);
|
||
|
||
/* Handle non-load insns. */
|
||
switch (insn_class)
|
||
{
|
||
case TRAP_FREE:
|
||
return 1;
|
||
case TRAP_RISKY:
|
||
return 0;
|
||
default:;
|
||
}
|
||
|
||
/* Handle loads. */
|
||
if (!flag_schedule_speculative_load)
|
||
return 0;
|
||
IS_LOAD_INSN (insn) = 1;
|
||
switch (insn_class)
|
||
{
|
||
case IFREE:
|
||
return (1);
|
||
case IRISKY:
|
||
return 0;
|
||
case PFREE_CANDIDATE:
|
||
if (is_pfree (insn, bb_src, bb_trg))
|
||
return 1;
|
||
/* Don't 'break' here: PFREE-candidate is also PRISKY-candidate. */
|
||
case PRISKY_CANDIDATE:
|
||
if (!flag_schedule_speculative_load_dangerous
|
||
|| is_prisky (insn, bb_src, bb_trg))
|
||
return 0;
|
||
break;
|
||
default:;
|
||
}
|
||
|
||
return flag_schedule_speculative_load_dangerous;
|
||
}
|
||
|
||
/* The number of insns from the current block scheduled so far. */
|
||
static int sched_target_n_insns;
|
||
/* The number of insns from the current block to be scheduled in total. */
|
||
static int target_n_insns;
|
||
/* The number of insns from the entire region scheduled so far. */
|
||
static int sched_n_insns;
|
||
/* Nonzero if the last scheduled insn was a jump. */
|
||
static int last_was_jump;
|
||
|
||
/* Implementations of the sched_info functions for region scheduling. */
|
||
static void init_ready_list PARAMS ((struct ready_list *));
|
||
static int can_schedule_ready_p PARAMS ((rtx));
|
||
static int new_ready PARAMS ((rtx));
|
||
static int schedule_more_p PARAMS ((void));
|
||
static const char *rgn_print_insn PARAMS ((rtx, int));
|
||
static int rgn_rank PARAMS ((rtx, rtx));
|
||
static int contributes_to_priority PARAMS ((rtx, rtx));
|
||
static void compute_jump_reg_dependencies PARAMS ((rtx, regset));
|
||
|
||
/* Return nonzero if there are more insns that should be scheduled. */
|
||
|
||
static int
|
||
schedule_more_p ()
|
||
{
|
||
return ! last_was_jump && sched_target_n_insns < target_n_insns;
|
||
}
|
||
|
||
/* Add all insns that are initially ready to the ready list READY. Called
|
||
once before scheduling a set of insns. */
|
||
|
||
static void
|
||
init_ready_list (ready)
|
||
struct ready_list *ready;
|
||
{
|
||
rtx prev_head = current_sched_info->prev_head;
|
||
rtx next_tail = current_sched_info->next_tail;
|
||
int bb_src;
|
||
rtx insn;
|
||
|
||
target_n_insns = 0;
|
||
sched_target_n_insns = 0;
|
||
sched_n_insns = 0;
|
||
last_was_jump = 0;
|
||
|
||
/* Print debugging information. */
|
||
if (sched_verbose >= 5)
|
||
debug_dependencies ();
|
||
|
||
/* Prepare current target block info. */
|
||
if (current_nr_blocks > 1)
|
||
{
|
||
candidate_table = (candidate *) xmalloc (current_nr_blocks
|
||
* sizeof (candidate));
|
||
|
||
bblst_last = 0;
|
||
/* bblst_table holds split blocks and update blocks for each block after
|
||
the current one in the region. split blocks and update blocks are
|
||
the TO blocks of region edges, so there can be at most rgn_nr_edges
|
||
of them. */
|
||
bblst_size = (current_nr_blocks - target_bb) * rgn_nr_edges;
|
||
bblst_table = (int *) xmalloc (bblst_size * sizeof (int));
|
||
|
||
bitlst_table_last = 0;
|
||
bitlst_table_size = rgn_nr_edges;
|
||
bitlst_table = (int *) xmalloc (rgn_nr_edges * sizeof (int));
|
||
|
||
compute_trg_info (target_bb);
|
||
}
|
||
|
||
/* Initialize ready list with all 'ready' insns in target block.
|
||
Count number of insns in the target block being scheduled. */
|
||
for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn))
|
||
{
|
||
rtx next;
|
||
|
||
if (! INSN_P (insn))
|
||
continue;
|
||
next = NEXT_INSN (insn);
|
||
|
||
if (INSN_DEP_COUNT (insn) == 0
|
||
&& (! INSN_P (next) || SCHED_GROUP_P (next) == 0))
|
||
ready_add (ready, insn);
|
||
if (!(SCHED_GROUP_P (insn)))
|
||
target_n_insns++;
|
||
}
|
||
|
||
/* Add to ready list all 'ready' insns in valid source blocks.
|
||
For speculative insns, check-live, exception-free, and
|
||
issue-delay. */
|
||
for (bb_src = target_bb + 1; bb_src < current_nr_blocks; bb_src++)
|
||
if (IS_VALID (bb_src))
|
||
{
|
||
rtx src_head;
|
||
rtx src_next_tail;
|
||
rtx tail, head;
|
||
|
||
get_block_head_tail (BB_TO_BLOCK (bb_src), &head, &tail);
|
||
src_next_tail = NEXT_INSN (tail);
|
||
src_head = head;
|
||
|
||
for (insn = src_head; insn != src_next_tail; insn = NEXT_INSN (insn))
|
||
{
|
||
if (! INSN_P (insn))
|
||
continue;
|
||
|
||
if (!CANT_MOVE (insn)
|
||
&& (!IS_SPECULATIVE_INSN (insn)
|
||
|| ((((!targetm.sched.use_dfa_pipeline_interface
|
||
|| !(*targetm.sched.use_dfa_pipeline_interface) ())
|
||
&& insn_issue_delay (insn) <= 3)
|
||
|| (targetm.sched.use_dfa_pipeline_interface
|
||
&& (*targetm.sched.use_dfa_pipeline_interface) ()
|
||
&& (recog_memoized (insn) < 0
|
||
|| min_insn_conflict_delay (curr_state,
|
||
insn, insn) <= 3)))
|
||
&& check_live (insn, bb_src)
|
||
&& is_exception_free (insn, bb_src, target_bb))))
|
||
{
|
||
rtx next;
|
||
|
||
/* Note that we haven't squirreled away the notes for
|
||
blocks other than the current. So if this is a
|
||
speculative insn, NEXT might otherwise be a note. */
|
||
next = next_nonnote_insn (insn);
|
||
if (INSN_DEP_COUNT (insn) == 0
|
||
&& (! next
|
||
|| ! INSN_P (next)
|
||
|| SCHED_GROUP_P (next) == 0))
|
||
ready_add (ready, insn);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Called after taking INSN from the ready list. Returns nonzero if this
|
||
insn can be scheduled, nonzero if we should silently discard it. */
|
||
|
||
static int
|
||
can_schedule_ready_p (insn)
|
||
rtx insn;
|
||
{
|
||
if (GET_CODE (insn) == JUMP_INSN)
|
||
last_was_jump = 1;
|
||
|
||
/* An interblock motion? */
|
||
if (INSN_BB (insn) != target_bb)
|
||
{
|
||
rtx temp;
|
||
basic_block b1;
|
||
|
||
if (IS_SPECULATIVE_INSN (insn))
|
||
{
|
||
if (!check_live (insn, INSN_BB (insn)))
|
||
return 0;
|
||
update_live (insn, INSN_BB (insn));
|
||
|
||
/* For speculative load, mark insns fed by it. */
|
||
if (IS_LOAD_INSN (insn) || FED_BY_SPEC_LOAD (insn))
|
||
set_spec_fed (insn);
|
||
|
||
nr_spec++;
|
||
}
|
||
nr_inter++;
|
||
|
||
/* Find the beginning of the scheduling group. */
|
||
/* ??? Ought to update basic block here, but later bits of
|
||
schedule_block assumes the original insn block is
|
||
still intact. */
|
||
|
||
temp = insn;
|
||
while (SCHED_GROUP_P (temp))
|
||
temp = PREV_INSN (temp);
|
||
|
||
/* Update source block boundaries. */
|
||
b1 = BLOCK_FOR_INSN (temp);
|
||
if (temp == b1->head && insn == b1->end)
|
||
{
|
||
/* We moved all the insns in the basic block.
|
||
Emit a note after the last insn and update the
|
||
begin/end boundaries to point to the note. */
|
||
rtx note = emit_note_after (NOTE_INSN_DELETED, insn);
|
||
b1->head = note;
|
||
b1->end = note;
|
||
}
|
||
else if (insn == b1->end)
|
||
{
|
||
/* We took insns from the end of the basic block,
|
||
so update the end of block boundary so that it
|
||
points to the first insn we did not move. */
|
||
b1->end = PREV_INSN (temp);
|
||
}
|
||
else if (temp == b1->head)
|
||
{
|
||
/* We took insns from the start of the basic block,
|
||
so update the start of block boundary so that
|
||
it points to the first insn we did not move. */
|
||
b1->head = NEXT_INSN (insn);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* In block motion. */
|
||
sched_target_n_insns++;
|
||
}
|
||
sched_n_insns++;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* Called after INSN has all its dependencies resolved. Return nonzero
|
||
if it should be moved to the ready list or the queue, or zero if we
|
||
should silently discard it. */
|
||
static int
|
||
new_ready (next)
|
||
rtx next;
|
||
{
|
||
/* For speculative insns, before inserting to ready/queue,
|
||
check live, exception-free, and issue-delay. */
|
||
if (INSN_BB (next) != target_bb
|
||
&& (!IS_VALID (INSN_BB (next))
|
||
|| CANT_MOVE (next)
|
||
|| (IS_SPECULATIVE_INSN (next)
|
||
&& (0
|
||
|| (targetm.sched.use_dfa_pipeline_interface
|
||
&& (*targetm.sched.use_dfa_pipeline_interface) ()
|
||
&& recog_memoized (next) >= 0
|
||
&& min_insn_conflict_delay (curr_state, next,
|
||
next) > 3)
|
||
|| ((!targetm.sched.use_dfa_pipeline_interface
|
||
|| !(*targetm.sched.use_dfa_pipeline_interface) ())
|
||
&& insn_issue_delay (next) > 3)
|
||
|| !check_live (next, INSN_BB (next))
|
||
|| !is_exception_free (next, INSN_BB (next), target_bb)))))
|
||
return 0;
|
||
return 1;
|
||
}
|
||
|
||
/* Return a string that contains the insn uid and optionally anything else
|
||
necessary to identify this insn in an output. It's valid to use a
|
||
static buffer for this. The ALIGNED parameter should cause the string
|
||
to be formatted so that multiple output lines will line up nicely. */
|
||
|
||
static const char *
|
||
rgn_print_insn (insn, aligned)
|
||
rtx insn;
|
||
int aligned;
|
||
{
|
||
static char tmp[80];
|
||
|
||
if (aligned)
|
||
sprintf (tmp, "b%3d: i%4d", INSN_BB (insn), INSN_UID (insn));
|
||
else
|
||
{
|
||
if (current_nr_blocks > 1 && INSN_BB (insn) != target_bb)
|
||
sprintf (tmp, "%d/b%d", INSN_UID (insn), INSN_BB (insn));
|
||
else
|
||
sprintf (tmp, "%d", INSN_UID (insn));
|
||
}
|
||
return tmp;
|
||
}
|
||
|
||
/* Compare priority of two insns. Return a positive number if the second
|
||
insn is to be preferred for scheduling, and a negative one if the first
|
||
is to be preferred. Zero if they are equally good. */
|
||
|
||
static int
|
||
rgn_rank (insn1, insn2)
|
||
rtx insn1, insn2;
|
||
{
|
||
/* Some comparison make sense in interblock scheduling only. */
|
||
if (INSN_BB (insn1) != INSN_BB (insn2))
|
||
{
|
||
int spec_val, prob_val;
|
||
|
||
/* Prefer an inblock motion on an interblock motion. */
|
||
if ((INSN_BB (insn2) == target_bb) && (INSN_BB (insn1) != target_bb))
|
||
return 1;
|
||
if ((INSN_BB (insn1) == target_bb) && (INSN_BB (insn2) != target_bb))
|
||
return -1;
|
||
|
||
/* Prefer a useful motion on a speculative one. */
|
||
spec_val = IS_SPECULATIVE_INSN (insn1) - IS_SPECULATIVE_INSN (insn2);
|
||
if (spec_val)
|
||
return spec_val;
|
||
|
||
/* Prefer a more probable (speculative) insn. */
|
||
prob_val = INSN_PROBABILITY (insn2) - INSN_PROBABILITY (insn1);
|
||
if (prob_val)
|
||
return prob_val;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
/* NEXT is an instruction that depends on INSN (a backward dependence);
|
||
return nonzero if we should include this dependence in priority
|
||
calculations. */
|
||
|
||
static int
|
||
contributes_to_priority (next, insn)
|
||
rtx next, insn;
|
||
{
|
||
return BLOCK_NUM (next) == BLOCK_NUM (insn);
|
||
}
|
||
|
||
/* INSN is a JUMP_INSN. Store the set of registers that must be considered
|
||
to be set by this jump in SET. */
|
||
|
||
static void
|
||
compute_jump_reg_dependencies (insn, set)
|
||
rtx insn ATTRIBUTE_UNUSED;
|
||
regset set ATTRIBUTE_UNUSED;
|
||
{
|
||
/* Nothing to do here, since we postprocess jumps in
|
||
add_branch_dependences. */
|
||
}
|
||
|
||
/* Used in schedule_insns to initialize current_sched_info for scheduling
|
||
regions (or single basic blocks). */
|
||
|
||
static struct sched_info region_sched_info =
|
||
{
|
||
init_ready_list,
|
||
can_schedule_ready_p,
|
||
schedule_more_p,
|
||
new_ready,
|
||
rgn_rank,
|
||
rgn_print_insn,
|
||
contributes_to_priority,
|
||
compute_jump_reg_dependencies,
|
||
|
||
NULL, NULL,
|
||
NULL, NULL,
|
||
0, 0
|
||
};
|
||
|
||
/* Determine if PAT sets a CLASS_LIKELY_SPILLED_P register. */
|
||
|
||
static bool
|
||
sets_likely_spilled (pat)
|
||
rtx pat;
|
||
{
|
||
bool ret = false;
|
||
note_stores (pat, sets_likely_spilled_1, &ret);
|
||
return ret;
|
||
}
|
||
|
||
static void
|
||
sets_likely_spilled_1 (x, pat, data)
|
||
rtx x, pat;
|
||
void *data;
|
||
{
|
||
bool *ret = (bool *) data;
|
||
|
||
if (GET_CODE (pat) == SET
|
||
&& REG_P (x)
|
||
&& REGNO (x) < FIRST_PSEUDO_REGISTER
|
||
&& CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
|
||
*ret = true;
|
||
}
|
||
|
||
/* Add dependences so that branches are scheduled to run last in their
|
||
block. */
|
||
|
||
static void
|
||
add_branch_dependences (head, tail)
|
||
rtx head, tail;
|
||
{
|
||
rtx insn, last;
|
||
|
||
/* For all branches, calls, uses, clobbers, cc0 setters, and instructions
|
||
that can throw exceptions, force them to remain in order at the end of
|
||
the block by adding dependencies and giving the last a high priority.
|
||
There may be notes present, and prev_head may also be a note.
|
||
|
||
Branches must obviously remain at the end. Calls should remain at the
|
||
end since moving them results in worse register allocation. Uses remain
|
||
at the end to ensure proper register allocation.
|
||
|
||
cc0 setters remaim at the end because they can't be moved away from
|
||
their cc0 user.
|
||
|
||
Insns setting CLASS_LIKELY_SPILLED_P registers (usually return values)
|
||
are not moved before reload because we can wind up with register
|
||
allocation failures. */
|
||
|
||
insn = tail;
|
||
last = 0;
|
||
while (GET_CODE (insn) == CALL_INSN
|
||
|| GET_CODE (insn) == JUMP_INSN
|
||
|| (GET_CODE (insn) == INSN
|
||
&& (GET_CODE (PATTERN (insn)) == USE
|
||
|| GET_CODE (PATTERN (insn)) == CLOBBER
|
||
|| can_throw_internal (insn)
|
||
#ifdef HAVE_cc0
|
||
|| sets_cc0_p (PATTERN (insn))
|
||
#endif
|
||
|| (!reload_completed
|
||
&& sets_likely_spilled (PATTERN (insn)))))
|
||
|| GET_CODE (insn) == NOTE)
|
||
{
|
||
if (GET_CODE (insn) != NOTE)
|
||
{
|
||
if (last != 0 && !find_insn_list (insn, LOG_LINKS (last)))
|
||
{
|
||
add_dependence (last, insn, REG_DEP_ANTI);
|
||
INSN_REF_COUNT (insn)++;
|
||
}
|
||
|
||
CANT_MOVE (insn) = 1;
|
||
|
||
last = insn;
|
||
/* Skip over insns that are part of a group.
|
||
Make each insn explicitly depend on the previous insn.
|
||
This ensures that only the group header will ever enter
|
||
the ready queue (and, when scheduled, will automatically
|
||
schedule the SCHED_GROUP_P block). */
|
||
while (SCHED_GROUP_P (insn))
|
||
{
|
||
rtx temp = prev_nonnote_insn (insn);
|
||
add_dependence (insn, temp, REG_DEP_ANTI);
|
||
insn = temp;
|
||
}
|
||
}
|
||
|
||
/* Don't overrun the bounds of the basic block. */
|
||
if (insn == head)
|
||
break;
|
||
|
||
insn = PREV_INSN (insn);
|
||
}
|
||
|
||
/* Make sure these insns are scheduled last in their block. */
|
||
insn = last;
|
||
if (insn != 0)
|
||
while (insn != head)
|
||
{
|
||
insn = prev_nonnote_insn (insn);
|
||
|
||
if (INSN_REF_COUNT (insn) != 0)
|
||
continue;
|
||
|
||
add_dependence (last, insn, REG_DEP_ANTI);
|
||
INSN_REF_COUNT (insn) = 1;
|
||
|
||
/* Skip over insns that are part of a group. */
|
||
while (SCHED_GROUP_P (insn))
|
||
insn = prev_nonnote_insn (insn);
|
||
}
|
||
}
|
||
|
||
/* Data structures for the computation of data dependences in a regions. We
|
||
keep one `deps' structure for every basic block. Before analyzing the
|
||
data dependences for a bb, its variables are initialized as a function of
|
||
the variables of its predecessors. When the analysis for a bb completes,
|
||
we save the contents to the corresponding bb_deps[bb] variable. */
|
||
|
||
static struct deps *bb_deps;
|
||
|
||
/* Duplicate the INSN_LIST elements of COPY and prepend them to OLD. */
|
||
|
||
static rtx
|
||
concat_INSN_LIST (copy, old)
|
||
rtx copy, old;
|
||
{
|
||
rtx new = old;
|
||
for (; copy ; copy = XEXP (copy, 1))
|
||
new = alloc_INSN_LIST (XEXP (copy, 0), new);
|
||
return new;
|
||
}
|
||
|
||
static void
|
||
concat_insn_mem_list (copy_insns, copy_mems, old_insns_p, old_mems_p)
|
||
rtx copy_insns, copy_mems;
|
||
rtx *old_insns_p, *old_mems_p;
|
||
{
|
||
rtx new_insns = *old_insns_p;
|
||
rtx new_mems = *old_mems_p;
|
||
|
||
while (copy_insns)
|
||
{
|
||
new_insns = alloc_INSN_LIST (XEXP (copy_insns, 0), new_insns);
|
||
new_mems = alloc_EXPR_LIST (VOIDmode, XEXP (copy_mems, 0), new_mems);
|
||
copy_insns = XEXP (copy_insns, 1);
|
||
copy_mems = XEXP (copy_mems, 1);
|
||
}
|
||
|
||
*old_insns_p = new_insns;
|
||
*old_mems_p = new_mems;
|
||
}
|
||
|
||
/* After computing the dependencies for block BB, propagate the dependencies
|
||
found in TMP_DEPS to the successors of the block. */
|
||
static void
|
||
propagate_deps (bb, pred_deps)
|
||
int bb;
|
||
struct deps *pred_deps;
|
||
{
|
||
int b = BB_TO_BLOCK (bb);
|
||
int e, first_edge;
|
||
|
||
/* bb's structures are inherited by its successors. */
|
||
first_edge = e = OUT_EDGES (b);
|
||
if (e > 0)
|
||
do
|
||
{
|
||
int b_succ = TO_BLOCK (e);
|
||
int bb_succ = BLOCK_TO_BB (b_succ);
|
||
struct deps *succ_deps = bb_deps + bb_succ;
|
||
int reg;
|
||
|
||
/* Only bbs "below" bb, in the same region, are interesting. */
|
||
if (CONTAINING_RGN (b) != CONTAINING_RGN (b_succ)
|
||
|| bb_succ <= bb)
|
||
{
|
||
e = NEXT_OUT (e);
|
||
continue;
|
||
}
|
||
|
||
/* The reg_last lists are inherited by bb_succ. */
|
||
EXECUTE_IF_SET_IN_REG_SET (&pred_deps->reg_last_in_use, 0, reg,
|
||
{
|
||
struct deps_reg *pred_rl = &pred_deps->reg_last[reg];
|
||
struct deps_reg *succ_rl = &succ_deps->reg_last[reg];
|
||
|
||
succ_rl->uses = concat_INSN_LIST (pred_rl->uses, succ_rl->uses);
|
||
succ_rl->sets = concat_INSN_LIST (pred_rl->sets, succ_rl->sets);
|
||
succ_rl->clobbers = concat_INSN_LIST (pred_rl->clobbers,
|
||
succ_rl->clobbers);
|
||
succ_rl->uses_length += pred_rl->uses_length;
|
||
succ_rl->clobbers_length += pred_rl->clobbers_length;
|
||
});
|
||
IOR_REG_SET (&succ_deps->reg_last_in_use, &pred_deps->reg_last_in_use);
|
||
|
||
/* Mem read/write lists are inherited by bb_succ. */
|
||
concat_insn_mem_list (pred_deps->pending_read_insns,
|
||
pred_deps->pending_read_mems,
|
||
&succ_deps->pending_read_insns,
|
||
&succ_deps->pending_read_mems);
|
||
concat_insn_mem_list (pred_deps->pending_write_insns,
|
||
pred_deps->pending_write_mems,
|
||
&succ_deps->pending_write_insns,
|
||
&succ_deps->pending_write_mems);
|
||
|
||
succ_deps->last_pending_memory_flush
|
||
= concat_INSN_LIST (pred_deps->last_pending_memory_flush,
|
||
succ_deps->last_pending_memory_flush);
|
||
|
||
succ_deps->pending_lists_length += pred_deps->pending_lists_length;
|
||
succ_deps->pending_flush_length += pred_deps->pending_flush_length;
|
||
|
||
/* last_function_call is inherited by bb_succ. */
|
||
succ_deps->last_function_call
|
||
= concat_INSN_LIST (pred_deps->last_function_call,
|
||
succ_deps->last_function_call);
|
||
|
||
/* sched_before_next_call is inherited by bb_succ. */
|
||
succ_deps->sched_before_next_call
|
||
= concat_INSN_LIST (pred_deps->sched_before_next_call,
|
||
succ_deps->sched_before_next_call);
|
||
|
||
e = NEXT_OUT (e);
|
||
}
|
||
while (e != first_edge);
|
||
|
||
/* These lists should point to the right place, for correct
|
||
freeing later. */
|
||
bb_deps[bb].pending_read_insns = pred_deps->pending_read_insns;
|
||
bb_deps[bb].pending_read_mems = pred_deps->pending_read_mems;
|
||
bb_deps[bb].pending_write_insns = pred_deps->pending_write_insns;
|
||
bb_deps[bb].pending_write_mems = pred_deps->pending_write_mems;
|
||
|
||
/* Can't allow these to be freed twice. */
|
||
pred_deps->pending_read_insns = 0;
|
||
pred_deps->pending_read_mems = 0;
|
||
pred_deps->pending_write_insns = 0;
|
||
pred_deps->pending_write_mems = 0;
|
||
}
|
||
|
||
/* Compute backward dependences inside bb. In a multiple blocks region:
|
||
(1) a bb is analyzed after its predecessors, and (2) the lists in
|
||
effect at the end of bb (after analyzing for bb) are inherited by
|
||
bb's successrs.
|
||
|
||
Specifically for reg-reg data dependences, the block insns are
|
||
scanned by sched_analyze () top-to-bottom. Two lists are
|
||
maintained by sched_analyze (): reg_last[].sets for register DEFs,
|
||
and reg_last[].uses for register USEs.
|
||
|
||
When analysis is completed for bb, we update for its successors:
|
||
; - DEFS[succ] = Union (DEFS [succ], DEFS [bb])
|
||
; - USES[succ] = Union (USES [succ], DEFS [bb])
|
||
|
||
The mechanism for computing mem-mem data dependence is very
|
||
similar, and the result is interblock dependences in the region. */
|
||
|
||
static void
|
||
compute_block_backward_dependences (bb)
|
||
int bb;
|
||
{
|
||
rtx head, tail;
|
||
struct deps tmp_deps;
|
||
|
||
tmp_deps = bb_deps[bb];
|
||
|
||
/* Do the analysis for this block. */
|
||
get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail);
|
||
sched_analyze (&tmp_deps, head, tail);
|
||
add_branch_dependences (head, tail);
|
||
|
||
if (current_nr_blocks > 1)
|
||
propagate_deps (bb, &tmp_deps);
|
||
|
||
/* Free up the INSN_LISTs. */
|
||
free_deps (&tmp_deps);
|
||
}
|
||
|
||
/* Remove all INSN_LISTs and EXPR_LISTs from the pending lists and add
|
||
them to the unused_*_list variables, so that they can be reused. */
|
||
|
||
static void
|
||
free_pending_lists ()
|
||
{
|
||
int bb;
|
||
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
{
|
||
free_INSN_LIST_list (&bb_deps[bb].pending_read_insns);
|
||
free_INSN_LIST_list (&bb_deps[bb].pending_write_insns);
|
||
free_EXPR_LIST_list (&bb_deps[bb].pending_read_mems);
|
||
free_EXPR_LIST_list (&bb_deps[bb].pending_write_mems);
|
||
}
|
||
}
|
||
|
||
/* Print dependences for debugging, callable from debugger. */
|
||
|
||
void
|
||
debug_dependencies ()
|
||
{
|
||
int bb;
|
||
|
||
fprintf (sched_dump, ";; --------------- forward dependences: ------------ \n");
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
{
|
||
if (1)
|
||
{
|
||
rtx head, tail;
|
||
rtx next_tail;
|
||
rtx insn;
|
||
|
||
get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail);
|
||
next_tail = NEXT_INSN (tail);
|
||
fprintf (sched_dump, "\n;; --- Region Dependences --- b %d bb %d \n",
|
||
BB_TO_BLOCK (bb), bb);
|
||
|
||
if (targetm.sched.use_dfa_pipeline_interface
|
||
&& (*targetm.sched.use_dfa_pipeline_interface) ())
|
||
{
|
||
fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%14s\n",
|
||
"insn", "code", "bb", "dep", "prio", "cost",
|
||
"reservation");
|
||
fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%14s\n",
|
||
"----", "----", "--", "---", "----", "----",
|
||
"-----------");
|
||
}
|
||
else
|
||
{
|
||
fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%11s%6s\n",
|
||
"insn", "code", "bb", "dep", "prio", "cost", "blockage", "units");
|
||
fprintf (sched_dump, ";; %7s%6s%6s%6s%6s%6s%11s%6s\n",
|
||
"----", "----", "--", "---", "----", "----", "--------", "-----");
|
||
}
|
||
|
||
for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
|
||
{
|
||
rtx link;
|
||
|
||
if (! INSN_P (insn))
|
||
{
|
||
int n;
|
||
fprintf (sched_dump, ";; %6d ", INSN_UID (insn));
|
||
if (GET_CODE (insn) == NOTE)
|
||
{
|
||
n = NOTE_LINE_NUMBER (insn);
|
||
if (n < 0)
|
||
fprintf (sched_dump, "%s\n", GET_NOTE_INSN_NAME (n));
|
||
else
|
||
fprintf (sched_dump, "line %d, file %s\n", n,
|
||
NOTE_SOURCE_FILE (insn));
|
||
}
|
||
else
|
||
fprintf (sched_dump, " {%s}\n", GET_RTX_NAME (GET_CODE (insn)));
|
||
continue;
|
||
}
|
||
|
||
if (targetm.sched.use_dfa_pipeline_interface
|
||
&& (*targetm.sched.use_dfa_pipeline_interface) ())
|
||
{
|
||
fprintf (sched_dump,
|
||
";; %s%5d%6d%6d%6d%6d%6d ",
|
||
(SCHED_GROUP_P (insn) ? "+" : " "),
|
||
INSN_UID (insn),
|
||
INSN_CODE (insn),
|
||
INSN_BB (insn),
|
||
INSN_DEP_COUNT (insn),
|
||
INSN_PRIORITY (insn),
|
||
insn_cost (insn, 0, 0));
|
||
|
||
if (recog_memoized (insn) < 0)
|
||
fprintf (sched_dump, "nothing");
|
||
else
|
||
print_reservation (sched_dump, insn);
|
||
}
|
||
else
|
||
{
|
||
int unit = insn_unit (insn);
|
||
int range
|
||
= (unit < 0
|
||
|| function_units[unit].blockage_range_function == 0
|
||
? 0
|
||
: function_units[unit].blockage_range_function (insn));
|
||
fprintf (sched_dump,
|
||
";; %s%5d%6d%6d%6d%6d%6d %3d -%3d ",
|
||
(SCHED_GROUP_P (insn) ? "+" : " "),
|
||
INSN_UID (insn),
|
||
INSN_CODE (insn),
|
||
INSN_BB (insn),
|
||
INSN_DEP_COUNT (insn),
|
||
INSN_PRIORITY (insn),
|
||
insn_cost (insn, 0, 0),
|
||
(int) MIN_BLOCKAGE_COST (range),
|
||
(int) MAX_BLOCKAGE_COST (range));
|
||
insn_print_units (insn);
|
||
}
|
||
|
||
fprintf (sched_dump, "\t: ");
|
||
for (link = INSN_DEPEND (insn); link; link = XEXP (link, 1))
|
||
fprintf (sched_dump, "%d ", INSN_UID (XEXP (link, 0)));
|
||
fprintf (sched_dump, "\n");
|
||
}
|
||
}
|
||
}
|
||
fprintf (sched_dump, "\n");
|
||
}
|
||
|
||
/* Schedule a region. A region is either an inner loop, a loop-free
|
||
subroutine, or a single basic block. Each bb in the region is
|
||
scheduled after its flow predecessors. */
|
||
|
||
static void
|
||
schedule_region (rgn)
|
||
int rgn;
|
||
{
|
||
int bb;
|
||
int rgn_n_insns = 0;
|
||
int sched_rgn_n_insns = 0;
|
||
|
||
/* Set variables for the current region. */
|
||
current_nr_blocks = RGN_NR_BLOCKS (rgn);
|
||
current_blocks = RGN_BLOCKS (rgn);
|
||
|
||
init_deps_global ();
|
||
|
||
/* Initializations for region data dependence analyisis. */
|
||
bb_deps = (struct deps *) xmalloc (sizeof (struct deps) * current_nr_blocks);
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
init_deps (bb_deps + bb);
|
||
|
||
/* Compute LOG_LINKS. */
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
compute_block_backward_dependences (bb);
|
||
|
||
/* Compute INSN_DEPEND. */
|
||
for (bb = current_nr_blocks - 1; bb >= 0; bb--)
|
||
{
|
||
rtx head, tail;
|
||
get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail);
|
||
|
||
compute_forward_dependences (head, tail);
|
||
}
|
||
|
||
/* Set priorities. */
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
{
|
||
rtx head, tail;
|
||
get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail);
|
||
|
||
rgn_n_insns += set_priorities (head, tail);
|
||
}
|
||
|
||
/* Compute interblock info: probabilities, split-edges, dominators, etc. */
|
||
if (current_nr_blocks > 1)
|
||
{
|
||
int i;
|
||
|
||
prob = (float *) xmalloc ((current_nr_blocks) * sizeof (float));
|
||
|
||
dom = sbitmap_vector_alloc (current_nr_blocks, current_nr_blocks);
|
||
sbitmap_vector_zero (dom, current_nr_blocks);
|
||
/* Edge to bit. */
|
||
rgn_nr_edges = 0;
|
||
edge_to_bit = (int *) xmalloc (nr_edges * sizeof (int));
|
||
for (i = 1; i < nr_edges; i++)
|
||
if (CONTAINING_RGN (FROM_BLOCK (i)) == rgn)
|
||
EDGE_TO_BIT (i) = rgn_nr_edges++;
|
||
rgn_edges = (int *) xmalloc (rgn_nr_edges * sizeof (int));
|
||
|
||
rgn_nr_edges = 0;
|
||
for (i = 1; i < nr_edges; i++)
|
||
if (CONTAINING_RGN (FROM_BLOCK (i)) == (rgn))
|
||
rgn_edges[rgn_nr_edges++] = i;
|
||
|
||
/* Split edges. */
|
||
pot_split = sbitmap_vector_alloc (current_nr_blocks, rgn_nr_edges);
|
||
sbitmap_vector_zero (pot_split, current_nr_blocks);
|
||
ancestor_edges = sbitmap_vector_alloc (current_nr_blocks, rgn_nr_edges);
|
||
sbitmap_vector_zero (ancestor_edges, current_nr_blocks);
|
||
|
||
/* Compute probabilities, dominators, split_edges. */
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
compute_dom_prob_ps (bb);
|
||
}
|
||
|
||
/* Now we can schedule all blocks. */
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
{
|
||
rtx head, tail;
|
||
int b = BB_TO_BLOCK (bb);
|
||
|
||
get_block_head_tail (b, &head, &tail);
|
||
|
||
if (no_real_insns_p (head, tail))
|
||
continue;
|
||
|
||
current_sched_info->prev_head = PREV_INSN (head);
|
||
current_sched_info->next_tail = NEXT_INSN (tail);
|
||
|
||
if (write_symbols != NO_DEBUG)
|
||
{
|
||
save_line_notes (b, head, tail);
|
||
rm_line_notes (head, 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);
|
||
note = XEXP (note, 1);
|
||
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);
|
||
|
||
target_bb = bb;
|
||
|
||
current_sched_info->queue_must_finish_empty
|
||
= current_nr_blocks > 1 && !flag_schedule_interblock;
|
||
|
||
schedule_block (b, rgn_n_insns);
|
||
sched_rgn_n_insns += sched_n_insns;
|
||
|
||
/* Update target block boundaries. */
|
||
if (head == BLOCK_HEAD (b))
|
||
BLOCK_HEAD (b) = current_sched_info->head;
|
||
if (tail == BLOCK_END (b))
|
||
BLOCK_END (b) = current_sched_info->tail;
|
||
|
||
/* Clean up. */
|
||
if (current_nr_blocks > 1)
|
||
{
|
||
free (candidate_table);
|
||
free (bblst_table);
|
||
free (bitlst_table);
|
||
}
|
||
}
|
||
|
||
/* Sanity check: verify that all region insns were scheduled. */
|
||
if (sched_rgn_n_insns != rgn_n_insns)
|
||
abort ();
|
||
|
||
/* Restore line notes. */
|
||
if (write_symbols != NO_DEBUG)
|
||
{
|
||
for (bb = 0; bb < current_nr_blocks; bb++)
|
||
{
|
||
rtx head, tail;
|
||
get_block_head_tail (BB_TO_BLOCK (bb), &head, &tail);
|
||
restore_line_notes (head, tail);
|
||
}
|
||
}
|
||
|
||
/* Done with this region. */
|
||
free_pending_lists ();
|
||
|
||
finish_deps_global ();
|
||
|
||
free (bb_deps);
|
||
|
||
if (current_nr_blocks > 1)
|
||
{
|
||
free (prob);
|
||
sbitmap_vector_free (dom);
|
||
sbitmap_vector_free (pot_split);
|
||
sbitmap_vector_free (ancestor_edges);
|
||
free (edge_to_bit);
|
||
free (rgn_edges);
|
||
}
|
||
}
|
||
|
||
/* Indexed by region, holds the number of death notes found in that region.
|
||
Used for consistency checks. */
|
||
static int *deaths_in_region;
|
||
|
||
/* Initialize data structures for region scheduling. */
|
||
|
||
static void
|
||
init_regions ()
|
||
{
|
||
sbitmap blocks;
|
||
int rgn;
|
||
|
||
nr_regions = 0;
|
||
rgn_table = (region *) xmalloc ((n_basic_blocks) * sizeof (region));
|
||
rgn_bb_table = (int *) xmalloc ((n_basic_blocks) * sizeof (int));
|
||
block_to_bb = (int *) xmalloc ((last_basic_block) * sizeof (int));
|
||
containing_rgn = (int *) xmalloc ((last_basic_block) * sizeof (int));
|
||
|
||
/* Compute regions for scheduling. */
|
||
if (reload_completed
|
||
|| n_basic_blocks == 1
|
||
|| !flag_schedule_interblock)
|
||
{
|
||
find_single_block_region ();
|
||
}
|
||
else
|
||
{
|
||
/* Verify that a 'good' control flow graph can be built. */
|
||
if (is_cfg_nonregular ())
|
||
{
|
||
find_single_block_region ();
|
||
}
|
||
else
|
||
{
|
||
dominance_info dom;
|
||
struct edge_list *edge_list;
|
||
|
||
/* The scheduler runs after flow; therefore, we can't blindly call
|
||
back into find_basic_blocks since doing so could invalidate the
|
||
info in global_live_at_start.
|
||
|
||
Consider a block consisting entirely of dead stores; after life
|
||
analysis it would be a block of NOTE_INSN_DELETED notes. If
|
||
we call find_basic_blocks again, then the block would be removed
|
||
entirely and invalidate our the register live information.
|
||
|
||
We could (should?) recompute register live information. Doing
|
||
so may even be beneficial. */
|
||
edge_list = create_edge_list ();
|
||
|
||
/* Compute the dominators and post dominators. */
|
||
dom = calculate_dominance_info (CDI_DOMINATORS);
|
||
|
||
/* build_control_flow will return nonzero if it detects unreachable
|
||
blocks or any other irregularity with the cfg which prevents
|
||
cross block scheduling. */
|
||
if (build_control_flow (edge_list) != 0)
|
||
find_single_block_region ();
|
||
else
|
||
find_rgns (edge_list, dom);
|
||
|
||
if (sched_verbose >= 3)
|
||
debug_regions ();
|
||
|
||
/* We are done with flow's edge list. */
|
||
free_edge_list (edge_list);
|
||
|
||
/* For now. This will move as more and more of haifa is converted
|
||
to using the cfg code in flow.c. */
|
||
free_dominance_info (dom);
|
||
}
|
||
}
|
||
|
||
|
||
if (CHECK_DEAD_NOTES)
|
||
{
|
||
blocks = sbitmap_alloc (last_basic_block);
|
||
deaths_in_region = (int *) xmalloc (sizeof (int) * nr_regions);
|
||
/* Remove all death notes from the subroutine. */
|
||
for (rgn = 0; rgn < nr_regions; rgn++)
|
||
{
|
||
int b;
|
||
|
||
sbitmap_zero (blocks);
|
||
for (b = RGN_NR_BLOCKS (rgn) - 1; b >= 0; --b)
|
||
SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn) + b]);
|
||
|
||
deaths_in_region[rgn] = count_or_remove_death_notes (blocks, 1);
|
||
}
|
||
sbitmap_free (blocks);
|
||
}
|
||
else
|
||
count_or_remove_death_notes (NULL, 1);
|
||
}
|
||
|
||
/* The one entry point in this file. DUMP_FILE is the dump file for
|
||
this pass. */
|
||
|
||
void
|
||
schedule_insns (dump_file)
|
||
FILE *dump_file;
|
||
{
|
||
sbitmap large_region_blocks, blocks;
|
||
int rgn;
|
||
int any_large_regions;
|
||
basic_block bb;
|
||
|
||
/* Taking care of this degenerate case makes the rest of
|
||
this code simpler. */
|
||
if (n_basic_blocks == 0)
|
||
return;
|
||
|
||
nr_inter = 0;
|
||
nr_spec = 0;
|
||
|
||
sched_init (dump_file);
|
||
|
||
init_regions ();
|
||
|
||
current_sched_info = ®ion_sched_info;
|
||
|
||
/* Schedule every region in the subroutine. */
|
||
for (rgn = 0; rgn < nr_regions; rgn++)
|
||
schedule_region (rgn);
|
||
|
||
/* Update life analysis for the subroutine. Do single block regions
|
||
first so that we can verify that live_at_start didn't change. Then
|
||
do all other blocks. */
|
||
/* ??? There is an outside possibility that update_life_info, or more
|
||
to the point propagate_block, could get called with nonzero flags
|
||
more than once for one basic block. This would be kinda bad if it
|
||
were to happen, since REG_INFO would be accumulated twice for the
|
||
block, and we'd have twice the REG_DEAD notes.
|
||
|
||
I'm fairly certain that this _shouldn't_ happen, since I don't think
|
||
that live_at_start should change at region heads. Not sure what the
|
||
best way to test for this kind of thing... */
|
||
|
||
allocate_reg_life_data ();
|
||
compute_bb_for_insn ();
|
||
|
||
any_large_regions = 0;
|
||
large_region_blocks = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (large_region_blocks);
|
||
FOR_EACH_BB (bb)
|
||
SET_BIT (large_region_blocks, bb->index);
|
||
|
||
blocks = sbitmap_alloc (last_basic_block);
|
||
sbitmap_zero (blocks);
|
||
|
||
/* Update life information. For regions consisting of multiple blocks
|
||
we've possibly done interblock scheduling that affects global liveness.
|
||
For regions consisting of single blocks we need to do only local
|
||
liveness. */
|
||
for (rgn = 0; rgn < nr_regions; rgn++)
|
||
if (RGN_NR_BLOCKS (rgn) > 1)
|
||
any_large_regions = 1;
|
||
else
|
||
{
|
||
SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn)]);
|
||
RESET_BIT (large_region_blocks, rgn_bb_table[RGN_BLOCKS (rgn)]);
|
||
}
|
||
|
||
/* Don't update reg info after reload, since that affects
|
||
regs_ever_live, which should not change after reload. */
|
||
update_life_info (blocks, UPDATE_LIFE_LOCAL,
|
||
(reload_completed ? PROP_DEATH_NOTES
|
||
: PROP_DEATH_NOTES | PROP_REG_INFO));
|
||
if (any_large_regions)
|
||
{
|
||
update_life_info (large_region_blocks, UPDATE_LIFE_GLOBAL,
|
||
PROP_DEATH_NOTES | PROP_REG_INFO);
|
||
}
|
||
|
||
if (CHECK_DEAD_NOTES)
|
||
{
|
||
/* Verify the counts of basic block notes in single the basic block
|
||
regions. */
|
||
for (rgn = 0; rgn < nr_regions; rgn++)
|
||
if (RGN_NR_BLOCKS (rgn) == 1)
|
||
{
|
||
sbitmap_zero (blocks);
|
||
SET_BIT (blocks, rgn_bb_table[RGN_BLOCKS (rgn)]);
|
||
|
||
if (deaths_in_region[rgn]
|
||
!= count_or_remove_death_notes (blocks, 0))
|
||
abort ();
|
||
}
|
||
free (deaths_in_region);
|
||
}
|
||
|
||
/* Reposition the prologue and epilogue notes in case we moved the
|
||
prologue/epilogue insns. */
|
||
if (reload_completed)
|
||
reposition_prologue_and_epilogue_notes (get_insns ());
|
||
|
||
/* Delete redundant line notes. */
|
||
if (write_symbols != NO_DEBUG)
|
||
rm_redundant_line_notes ();
|
||
|
||
if (sched_verbose)
|
||
{
|
||
if (reload_completed == 0 && flag_schedule_interblock)
|
||
{
|
||
fprintf (sched_dump,
|
||
"\n;; Procedure interblock/speculative motions == %d/%d \n",
|
||
nr_inter, nr_spec);
|
||
}
|
||
else
|
||
{
|
||
if (nr_inter > 0)
|
||
abort ();
|
||
}
|
||
fprintf (sched_dump, "\n\n");
|
||
}
|
||
|
||
/* Clean up. */
|
||
free (rgn_table);
|
||
free (rgn_bb_table);
|
||
free (block_to_bb);
|
||
free (containing_rgn);
|
||
|
||
sched_finish ();
|
||
|
||
if (edge_table)
|
||
{
|
||
free (edge_table);
|
||
edge_table = NULL;
|
||
}
|
||
|
||
if (in_edges)
|
||
{
|
||
free (in_edges);
|
||
in_edges = NULL;
|
||
}
|
||
if (out_edges)
|
||
{
|
||
free (out_edges);
|
||
out_edges = NULL;
|
||
}
|
||
|
||
sbitmap_free (blocks);
|
||
sbitmap_free (large_region_blocks);
|
||
}
|
||
#endif
|