/* Global common subexpression elimination/Partial redundancy elimination
and global constant/copy propagation for GNU compiler.
- Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
+ Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "toplev.h"
#include "rtl.h"
+#include "tree.h"
#include "tm_p.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "except.h"
#include "ggc.h"
#include "params.h"
-
+#include "cselib.h"
+#include "intl.h"
#include "obstack.h"
-#define obstack_chunk_alloc gmalloc
-#define obstack_chunk_free free
/* Propagate flow information through back edges and thus enable PRE's
moving loop invariant calculations out of loops.
be done by loop.c, which has more heuristics for when to move invariants
out of loops. At some point we might need to move some of those
heuristics into gcse.c. */
-#define FOLLOW_BACK_EDGES 1
/* We support GCSE via Partial Redundancy Elimination. PRE optimizations
are a superset of those done by GCSE.
/* An obstack for our working variables. */
static struct obstack gcse_obstack;
-/* Non-zero for each mode that supports (set (reg) (reg)).
- This is trivially true for integer and floating point values.
- It may or may not be true for condition codes. */
-static char can_copy_p[(int) NUM_MACHINE_MODES];
-
-/* Non-zero if can_copy_p has been initialized. */
-static int can_copy_init_p;
-
struct reg_use {rtx reg_rtx; };
/* Hash table of expressions. */
struct occr *next;
/* The insn that computes the expression. */
rtx insn;
- /* Non-zero if this [anticipatable] occurrence has been deleted. */
+ /* Nonzero if this [anticipatable] occurrence has been deleted. */
char deleted_p;
- /* Non-zero if this [available] occurrence has been copied to
+ /* Nonzero if this [available] occurrence has been copied to
reaching_reg. */
/* ??? This is mutually exclusive with deleted_p, so they could share
the same byte. */
[one could build a mapping table without holes afterwards though].
Someday I'll perform the computation and figure it out. */
-/* Total size of the expression hash table, in elements. */
-static unsigned int expr_hash_table_size;
+struct hash_table
+{
+ /* The table itself.
+ This is an array of `expr_hash_table_size' elements. */
+ struct expr **table;
+
+ /* Size of the hash table, in elements. */
+ unsigned int size;
+
+ /* Number of hash table elements. */
+ unsigned int n_elems;
-/* The table itself.
- This is an array of `expr_hash_table_size' elements. */
-static struct expr **expr_hash_table;
+ /* Whether the table is expression of copy propagation one. */
+ int set_p;
+};
-/* Total size of the copy propagation hash table, in elements. */
-static unsigned int set_hash_table_size;
+/* Expression hash table. */
+static struct hash_table expr_hash_table;
-/* The table itself.
- This is an array of `set_hash_table_size' elements. */
-static struct expr **set_hash_table;
+/* Copy propagation hash table. */
+static struct hash_table set_hash_table;
/* Mapping of uids to cuids.
Only real insns get cuids. */
This is named with "gcse" to not collide with global of same name. */
static unsigned int max_gcse_regno;
-/* Maximum number of cse-able expressions found. */
-static int n_exprs;
-
-/* Maximum number of assignments for copy propagation found. */
-static int n_sets;
-
/* Table of registers that are modified.
For each register, each element is a list of places where the pseudo-reg
{
struct expr * expr; /* Gcse expression reference for LM. */
rtx pattern; /* Pattern of this mem. */
+ rtx pattern_regs; /* List of registers mentioned by the mem. */
rtx loads; /* INSN list of loads seen. */
rtx stores; /* INSN list of stores seen. */
struct ls_expr * next; /* Next in the list. */
int invalid; /* Invalid for some reason. */
int index; /* If it maps to a bitmap index. */
- int hash_index; /* Index when in a hash table. */
+ unsigned int hash_index; /* Index when in a hash table. */
rtx reaching_reg; /* Register to use when re-writing. */
};
+/* Array of implicit set patterns indexed by basic block index. */
+static rtx *implicit_sets;
+
/* Head of the list of load/store memory refs. */
static struct ls_expr * pre_ldst_mems = NULL;
sbitmap *nonnull_killed;
};
\f
-static void compute_can_copy PARAMS ((void));
-static char *gmalloc PARAMS ((unsigned int));
-static char *grealloc PARAMS ((char *, unsigned int));
-static char *gcse_alloc PARAMS ((unsigned long));
-static void alloc_gcse_mem PARAMS ((rtx));
-static void free_gcse_mem PARAMS ((void));
-static void alloc_reg_set_mem PARAMS ((int));
-static void free_reg_set_mem PARAMS ((void));
-static int get_bitmap_width PARAMS ((int, int, int));
-static void record_one_set PARAMS ((int, rtx));
-static void record_set_info PARAMS ((rtx, rtx, void *));
-static void compute_sets PARAMS ((rtx));
-static void hash_scan_insn PARAMS ((rtx, int, int));
-static void hash_scan_set PARAMS ((rtx, rtx, int));
-static void hash_scan_clobber PARAMS ((rtx, rtx));
-static void hash_scan_call PARAMS ((rtx, rtx));
-static int want_to_gcse_p PARAMS ((rtx));
-static int oprs_unchanged_p PARAMS ((rtx, rtx, int));
-static int oprs_anticipatable_p PARAMS ((rtx, rtx));
-static int oprs_available_p PARAMS ((rtx, rtx));
-static void insert_expr_in_table PARAMS ((rtx, enum machine_mode, rtx,
- int, int));
-static void insert_set_in_table PARAMS ((rtx, rtx));
-static unsigned int hash_expr PARAMS ((rtx, enum machine_mode, int *, int));
-static unsigned int hash_expr_1 PARAMS ((rtx, enum machine_mode, int *));
-static unsigned int hash_string_1 PARAMS ((const char *));
-static unsigned int hash_set PARAMS ((int, int));
-static int expr_equiv_p PARAMS ((rtx, rtx));
-static void record_last_reg_set_info PARAMS ((rtx, int));
-static void record_last_mem_set_info PARAMS ((rtx));
-static void record_last_set_info PARAMS ((rtx, rtx, void *));
-static void compute_hash_table PARAMS ((int));
-static void alloc_set_hash_table PARAMS ((int));
-static void free_set_hash_table PARAMS ((void));
-static void compute_set_hash_table PARAMS ((void));
-static void alloc_expr_hash_table PARAMS ((unsigned int));
-static void free_expr_hash_table PARAMS ((void));
-static void compute_expr_hash_table PARAMS ((void));
-static void dump_hash_table PARAMS ((FILE *, const char *, struct expr **,
- int, int));
-static struct expr *lookup_expr PARAMS ((rtx));
-static struct expr *lookup_set PARAMS ((unsigned int, rtx));
-static struct expr *next_set PARAMS ((unsigned int, struct expr *));
-static void reset_opr_set_tables PARAMS ((void));
-static int oprs_not_set_p PARAMS ((rtx, rtx));
-static void mark_call PARAMS ((rtx));
-static void mark_set PARAMS ((rtx, rtx));
-static void mark_clobber PARAMS ((rtx, rtx));
-static void mark_oprs_set PARAMS ((rtx));
-static void alloc_cprop_mem PARAMS ((int, int));
-static void free_cprop_mem PARAMS ((void));
-static void compute_transp PARAMS ((rtx, int, sbitmap *, int));
-static void compute_transpout PARAMS ((void));
-static void compute_local_properties PARAMS ((sbitmap *, sbitmap *, sbitmap *,
- int));
-static void compute_cprop_data PARAMS ((void));
-static void find_used_regs PARAMS ((rtx *, void *));
-static int try_replace_reg PARAMS ((rtx, rtx, rtx));
-static struct expr *find_avail_set PARAMS ((int, rtx));
-static int cprop_jump PARAMS ((basic_block, rtx, rtx, rtx, rtx));
-static void mems_conflict_for_gcse_p PARAMS ((rtx, rtx, void *));
-static int load_killed_in_block_p PARAMS ((basic_block, int, rtx, int));
-static void canon_list_insert PARAMS ((rtx, rtx, void *));
-static int cprop_insn PARAMS ((basic_block, rtx, int));
-static int cprop PARAMS ((int));
-static int one_cprop_pass PARAMS ((int, int));
-static struct expr *find_bypass_set PARAMS ((int, int));
-static int bypass_block PARAMS ((basic_block, rtx, rtx));
-static int bypass_conditional_jumps PARAMS ((void));
-static void alloc_pre_mem PARAMS ((int, int));
-static void free_pre_mem PARAMS ((void));
-static void compute_pre_data PARAMS ((void));
-static int pre_expr_reaches_here_p PARAMS ((basic_block, struct expr *,
- basic_block));
-static void insert_insn_end_bb PARAMS ((struct expr *, basic_block, int));
-static void pre_insert_copy_insn PARAMS ((struct expr *, rtx));
-static void pre_insert_copies PARAMS ((void));
-static int pre_delete PARAMS ((void));
-static int pre_gcse PARAMS ((void));
-static int one_pre_gcse_pass PARAMS ((int));
-static void add_label_notes PARAMS ((rtx, rtx));
-static void alloc_code_hoist_mem PARAMS ((int, int));
-static void free_code_hoist_mem PARAMS ((void));
-static void compute_code_hoist_vbeinout PARAMS ((void));
-static void compute_code_hoist_data PARAMS ((void));
-static int hoist_expr_reaches_here_p PARAMS ((basic_block, int, basic_block,
- char *));
-static void hoist_code PARAMS ((void));
-static int one_code_hoisting_pass PARAMS ((void));
-static void alloc_rd_mem PARAMS ((int, int));
-static void free_rd_mem PARAMS ((void));
-static void handle_rd_kill_set PARAMS ((rtx, int, basic_block));
-static void compute_kill_rd PARAMS ((void));
-static void compute_rd PARAMS ((void));
-static void alloc_avail_expr_mem PARAMS ((int, int));
-static void free_avail_expr_mem PARAMS ((void));
-static void compute_ae_gen PARAMS ((void));
-static int expr_killed_p PARAMS ((rtx, basic_block));
-static void compute_ae_kill PARAMS ((sbitmap *, sbitmap *));
-static int expr_reaches_here_p PARAMS ((struct occr *, struct expr *,
- basic_block, int));
-static rtx computing_insn PARAMS ((struct expr *, rtx));
-static int def_reaches_here_p PARAMS ((rtx, rtx));
-static int can_disregard_other_sets PARAMS ((struct reg_set **, rtx, int));
-static int handle_avail_expr PARAMS ((rtx, struct expr *));
-static int classic_gcse PARAMS ((void));
-static int one_classic_gcse_pass PARAMS ((int));
-static void invalidate_nonnull_info PARAMS ((rtx, rtx, void *));
-static int delete_null_pointer_checks_1 PARAMS ((unsigned int *,
- sbitmap *, sbitmap *,
- struct null_pointer_info *));
-static rtx process_insert_insn PARAMS ((struct expr *));
-static int pre_edge_insert PARAMS ((struct edge_list *, struct expr **));
-static int expr_reaches_here_p_work PARAMS ((struct occr *, struct expr *,
- basic_block, int, char *));
-static int pre_expr_reaches_here_p_work PARAMS ((basic_block, struct expr *,
- basic_block, char *));
-static struct ls_expr * ldst_entry PARAMS ((rtx));
-static void free_ldst_entry PARAMS ((struct ls_expr *));
-static void free_ldst_mems PARAMS ((void));
-static void print_ldst_list PARAMS ((FILE *));
-static struct ls_expr * find_rtx_in_ldst PARAMS ((rtx));
-static int enumerate_ldsts PARAMS ((void));
-static inline struct ls_expr * first_ls_expr PARAMS ((void));
-static inline struct ls_expr * next_ls_expr PARAMS ((struct ls_expr *));
-static int simple_mem PARAMS ((rtx));
-static void invalidate_any_buried_refs PARAMS ((rtx));
-static void compute_ld_motion_mems PARAMS ((void));
-static void trim_ld_motion_mems PARAMS ((void));
-static void update_ld_motion_stores PARAMS ((struct expr *));
-static void reg_set_info PARAMS ((rtx, rtx, void *));
-static int store_ops_ok PARAMS ((rtx, basic_block));
-static void find_moveable_store PARAMS ((rtx));
-static int compute_store_table PARAMS ((void));
-static int load_kills_store PARAMS ((rtx, rtx));
-static int find_loads PARAMS ((rtx, rtx));
-static int store_killed_in_insn PARAMS ((rtx, rtx));
-static int store_killed_after PARAMS ((rtx, rtx, basic_block));
-static int store_killed_before PARAMS ((rtx, rtx, basic_block));
-static void build_store_vectors PARAMS ((void));
-static void insert_insn_start_bb PARAMS ((rtx, basic_block));
-static int insert_store PARAMS ((struct ls_expr *, edge));
-static void replace_store_insn PARAMS ((rtx, rtx, basic_block));
-static void delete_store PARAMS ((struct ls_expr *,
- basic_block));
-static void free_store_memory PARAMS ((void));
-static void store_motion PARAMS ((void));
-static void free_insn_expr_list_list PARAMS ((rtx *));
-static void clear_modify_mem_tables PARAMS ((void));
-static void free_modify_mem_tables PARAMS ((void));
-static rtx gcse_emit_move_after PARAMS ((rtx, rtx, rtx));
+static void compute_can_copy (void);
+static void *gmalloc (size_t) ATTRIBUTE_MALLOC;
+static void *gcalloc (size_t, size_t) ATTRIBUTE_MALLOC;
+static void *grealloc (void *, size_t);
+static void *gcse_alloc (unsigned long);
+static void alloc_gcse_mem (rtx);
+static void free_gcse_mem (void);
+static void alloc_reg_set_mem (int);
+static void free_reg_set_mem (void);
+static int get_bitmap_width (int, int, int);
+static void record_one_set (int, rtx);
+static void replace_one_set (int, rtx, rtx);
+static void record_set_info (rtx, rtx, void *);
+static void compute_sets (rtx);
+static void hash_scan_insn (rtx, struct hash_table *, int);
+static void hash_scan_set (rtx, rtx, struct hash_table *);
+static void hash_scan_clobber (rtx, rtx, struct hash_table *);
+static void hash_scan_call (rtx, rtx, struct hash_table *);
+static int want_to_gcse_p (rtx);
+static bool gcse_constant_p (rtx);
+static int oprs_unchanged_p (rtx, rtx, int);
+static int oprs_anticipatable_p (rtx, rtx);
+static int oprs_available_p (rtx, rtx);
+static void insert_expr_in_table (rtx, enum machine_mode, rtx, int, int,
+ struct hash_table *);
+static void insert_set_in_table (rtx, rtx, struct hash_table *);
+static unsigned int hash_expr (rtx, enum machine_mode, int *, int);
+static unsigned int hash_expr_1 (rtx, enum machine_mode, int *);
+static unsigned int hash_string_1 (const char *);
+static unsigned int hash_set (int, int);
+static int expr_equiv_p (rtx, rtx);
+static void record_last_reg_set_info (rtx, int);
+static void record_last_mem_set_info (rtx);
+static void record_last_set_info (rtx, rtx, void *);
+static void compute_hash_table (struct hash_table *);
+static void alloc_hash_table (int, struct hash_table *, int);
+static void free_hash_table (struct hash_table *);
+static void compute_hash_table_work (struct hash_table *);
+static void dump_hash_table (FILE *, const char *, struct hash_table *);
+static struct expr *lookup_expr (rtx, struct hash_table *);
+static struct expr *lookup_set (unsigned int, struct hash_table *);
+static struct expr *next_set (unsigned int, struct expr *);
+static void reset_opr_set_tables (void);
+static int oprs_not_set_p (rtx, rtx);
+static void mark_call (rtx);
+static void mark_set (rtx, rtx);
+static void mark_clobber (rtx, rtx);
+static void mark_oprs_set (rtx);
+static void alloc_cprop_mem (int, int);
+static void free_cprop_mem (void);
+static void compute_transp (rtx, int, sbitmap *, int);
+static void compute_transpout (void);
+static void compute_local_properties (sbitmap *, sbitmap *, sbitmap *,
+ struct hash_table *);
+static void compute_cprop_data (void);
+static void find_used_regs (rtx *, void *);
+static int try_replace_reg (rtx, rtx, rtx);
+static struct expr *find_avail_set (int, rtx);
+static int cprop_jump (basic_block, rtx, rtx, rtx, rtx);
+static void mems_conflict_for_gcse_p (rtx, rtx, void *);
+static int load_killed_in_block_p (basic_block, int, rtx, int);
+static void canon_list_insert (rtx, rtx, void *);
+static int cprop_insn (rtx, int);
+static int cprop (int);
+static void find_implicit_sets (void);
+static int one_cprop_pass (int, int, int);
+static bool constprop_register (rtx, rtx, rtx, int);
+static struct expr *find_bypass_set (int, int);
+static bool reg_killed_on_edge (rtx, edge);
+static int bypass_block (basic_block, rtx, rtx);
+static int bypass_conditional_jumps (void);
+static void alloc_pre_mem (int, int);
+static void free_pre_mem (void);
+static void compute_pre_data (void);
+static int pre_expr_reaches_here_p (basic_block, struct expr *,
+ basic_block);
+static void insert_insn_end_bb (struct expr *, basic_block, int);
+static void pre_insert_copy_insn (struct expr *, rtx);
+static void pre_insert_copies (void);
+static int pre_delete (void);
+static int pre_gcse (void);
+static int one_pre_gcse_pass (int);
+static void add_label_notes (rtx, rtx);
+static void alloc_code_hoist_mem (int, int);
+static void free_code_hoist_mem (void);
+static void compute_code_hoist_vbeinout (void);
+static void compute_code_hoist_data (void);
+static int hoist_expr_reaches_here_p (basic_block, int, basic_block, char *);
+static void hoist_code (void);
+static int one_code_hoisting_pass (void);
+static void alloc_rd_mem (int, int);
+static void free_rd_mem (void);
+static void handle_rd_kill_set (rtx, int, basic_block);
+static void compute_kill_rd (void);
+static void compute_rd (void);
+static void alloc_avail_expr_mem (int, int);
+static void free_avail_expr_mem (void);
+static void compute_ae_gen (struct hash_table *);
+static int expr_killed_p (rtx, basic_block);
+static void compute_ae_kill (sbitmap *, sbitmap *, struct hash_table *);
+static int expr_reaches_here_p (struct occr *, struct expr *, basic_block,
+ int);
+static rtx computing_insn (struct expr *, rtx);
+static int def_reaches_here_p (rtx, rtx);
+static int can_disregard_other_sets (struct reg_set **, rtx, int);
+static int handle_avail_expr (rtx, struct expr *);
+static int classic_gcse (void);
+static int one_classic_gcse_pass (int);
+static void invalidate_nonnull_info (rtx, rtx, void *);
+static int delete_null_pointer_checks_1 (unsigned int *, sbitmap *, sbitmap *,
+ struct null_pointer_info *);
+static rtx process_insert_insn (struct expr *);
+static int pre_edge_insert (struct edge_list *, struct expr **);
+static int expr_reaches_here_p_work (struct occr *, struct expr *,
+ basic_block, int, char *);
+static int pre_expr_reaches_here_p_work (basic_block, struct expr *,
+ basic_block, char *);
+static struct ls_expr * ldst_entry (rtx);
+static void free_ldst_entry (struct ls_expr *);
+static void free_ldst_mems (void);
+static void print_ldst_list (FILE *);
+static struct ls_expr * find_rtx_in_ldst (rtx);
+static int enumerate_ldsts (void);
+static inline struct ls_expr * first_ls_expr (void);
+static inline struct ls_expr * next_ls_expr (struct ls_expr *);
+static int simple_mem (rtx);
+static void invalidate_any_buried_refs (rtx);
+static void compute_ld_motion_mems (void);
+static void trim_ld_motion_mems (void);
+static void update_ld_motion_stores (struct expr *);
+static void reg_set_info (rtx, rtx, void *);
+static void reg_clear_last_set (rtx, rtx, void *);
+static bool store_ops_ok (rtx, int *);
+static rtx extract_mentioned_regs (rtx);
+static rtx extract_mentioned_regs_helper (rtx, rtx);
+static void find_moveable_store (rtx, int *, int *);
+static int compute_store_table (void);
+static bool load_kills_store (rtx, rtx, int);
+static bool find_loads (rtx, rtx, int);
+static bool store_killed_in_insn (rtx, rtx, rtx, int);
+static bool store_killed_after (rtx, rtx, rtx, basic_block, int *, rtx *);
+static bool store_killed_before (rtx, rtx, rtx, basic_block, int *);
+static void build_store_vectors (void);
+static void insert_insn_start_bb (rtx, basic_block);
+static int insert_store (struct ls_expr *, edge);
+static void remove_reachable_equiv_notes (basic_block, struct ls_expr *);
+static void replace_store_insn (rtx, rtx, basic_block, struct ls_expr *);
+static void delete_store (struct ls_expr *, basic_block);
+static void free_store_memory (void);
+static void store_motion (void);
+static void free_insn_expr_list_list (rtx *);
+static void clear_modify_mem_tables (void);
+static void free_modify_mem_tables (void);
+static rtx gcse_emit_move_after (rtx, rtx, rtx);
+static void local_cprop_find_used_regs (rtx *, void *);
+static bool do_local_cprop (rtx, rtx, int, rtx*);
+static bool adjust_libcall_notes (rtx, rtx, rtx, rtx*);
+static void local_cprop_pass (int);
+static bool is_too_expensive (const char *);
\f
+
/* Entry point for global common subexpression elimination.
F is the first instruction in the function. */
int
-gcse_main (f, file)
- rtx f;
- FILE *file;
+gcse_main (rtx f, FILE *file)
{
int changed, pass;
/* Bytes used at start of pass. */
/* Point to release obstack data from for each pass. */
char *gcse_obstack_bottom;
- /* Insertion of instructions on edges can create new basic blocks; we
- need the original basic block count so that we can properly deallocate
- arrays sized on the number of basic blocks originally in the cfg. */
- int orig_bb_count;
/* We do not construct an accurate cfg in functions which call
setjmp, so just punt to be safe. */
if (current_function_calls_setjmp)
if (file)
dump_flow_info (file);
- orig_bb_count = n_basic_blocks;
- /* Return if there's nothing to do. */
- if (n_basic_blocks <= 1)
+ /* Return if there's nothing to do, or it is too expensive. */
+ if (n_basic_blocks <= 1 || is_too_expensive (_("GCSE disabled")))
return 0;
-
- /* Trying to perform global optimizations on flow graphs which have
- a high connectivity will take a long time and is unlikely to be
- particularly useful.
-
- In normal circumstances a cfg should have about twice as many edges
- as blocks. But we do not want to punish small functions which have
- a couple switch statements. So we require a relatively large number
- of basic blocks and the ratio of edges to blocks to be high. */
- if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20)
- {
- if (warn_disabled_optimization)
- warning ("GCSE disabled: %d > 1000 basic blocks and %d >= 20 edges/basic block",
- n_basic_blocks, n_edges / n_basic_blocks);
- return 0;
- }
-
- /* If allocating memory for the cprop bitmap would take up too much
- storage it's better just to disable the optimization. */
- if ((n_basic_blocks
- * SBITMAP_SET_SIZE (max_gcse_regno)
- * sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY)
- {
- if (warn_disabled_optimization)
- warning ("GCSE disabled: %d basic blocks and %d registers",
- n_basic_blocks, max_gcse_regno);
-
- return 0;
- }
-
- /* See what modes support reg/reg copy operations. */
- if (! can_copy_init_p)
- {
- compute_can_copy ();
- can_copy_init_p = 1;
- }
-
+
gcc_obstack_init (&gcse_obstack);
bytes_used = 0;
/* Don't allow constant propagation to modify jumps
during this pass. */
- changed = one_cprop_pass (pass + 1, 0);
+ changed = one_cprop_pass (pass + 1, 0, 0);
if (optimize_size)
changed |= one_classic_gcse_pass (pass + 1);
if (changed)
{
free_modify_mem_tables ();
- modify_mem_list
- = (rtx *) gmalloc (last_basic_block * sizeof (rtx));
- canon_modify_mem_list
- = (rtx *) gmalloc (last_basic_block * sizeof (rtx));
- memset ((char *) modify_mem_list, 0, last_basic_block * sizeof (rtx));
- memset ((char *) canon_modify_mem_list, 0, last_basic_block * sizeof (rtx));
- orig_bb_count = n_basic_blocks;
+ modify_mem_list = gcalloc (last_basic_block, sizeof (rtx));
+ canon_modify_mem_list = gcalloc (last_basic_block, sizeof (rtx));
}
free_reg_set_mem ();
alloc_reg_set_mem (max_reg_num ());
partial redundancy elimination. */
free_gcse_mem ();
- /* It does not make sense to run code hoisting unless we optimizing
+ /* It does not make sense to run code hoisting unless we are optimizing
for code size -- it rarely makes programs faster, and can make
them bigger if we did partial redundancy elimination (when optimizing
for space, we use a classic gcse algorithm instead of partial
max_gcse_regno = max_reg_num ();
alloc_gcse_mem (f);
/* This time, go ahead and allow cprop to alter jumps. */
- one_cprop_pass (pass + 1, 1);
+ one_cprop_pass (pass + 1, 1, 0);
free_gcse_mem ();
if (file)
{
fprintf (file, "GCSE of %s: %d basic blocks, ",
- current_function_name, n_basic_blocks);
+ current_function_name (), n_basic_blocks);
fprintf (file, "%d pass%s, %d bytes\n\n",
pass, pass > 1 ? "es" : "", max_pass_bytes);
}
end_alias_analysis ();
allocate_reg_info (max_reg_num (), FALSE, FALSE);
- /* Store motion disabled until it is fixed. */
- if (0 && !optimize_size && flag_gcse_sm)
+ if (!optimize_size && flag_gcse_sm)
store_motion ();
+
/* Record where pseudo-registers are set. */
return run_jump_opt_after_gcse;
}
\f
/* Misc. utilities. */
+/* Nonzero for each mode that supports (set (reg) (reg)).
+ This is trivially true for integer and floating point values.
+ It may or may not be true for condition codes. */
+static char can_copy[(int) NUM_MACHINE_MODES];
+
/* Compute which modes support reg/reg copy operations. */
static void
-compute_can_copy ()
+compute_can_copy (void)
{
int i;
#ifndef AVOID_CCMODE_COPIES
rtx reg, insn;
#endif
- memset (can_copy_p, 0, NUM_MACHINE_MODES);
+ memset (can_copy, 0, NUM_MACHINE_MODES);
start_sequence ();
for (i = 0; i < NUM_MACHINE_MODES; i++)
if (GET_MODE_CLASS (i) == MODE_CC)
{
#ifdef AVOID_CCMODE_COPIES
- can_copy_p[i] = 0;
+ can_copy[i] = 0;
#else
reg = gen_rtx_REG ((enum machine_mode) i, LAST_VIRTUAL_REGISTER + 1);
insn = emit_insn (gen_rtx_SET (VOIDmode, reg, reg));
if (recog (PATTERN (insn), insn, NULL) >= 0)
- can_copy_p[i] = 1;
+ can_copy[i] = 1;
#endif
}
else
- can_copy_p[i] = 1;
+ can_copy[i] = 1;
end_sequence ();
}
+
+/* Returns whether the mode supports reg/reg copy operations. */
+
+bool
+can_copy_p (enum machine_mode mode)
+{
+ static bool can_copy_init_p = false;
+
+ if (! can_copy_init_p)
+ {
+ compute_can_copy ();
+ can_copy_init_p = true;
+ }
+
+ return can_copy[mode] != 0;
+}
\f
/* Cover function to xmalloc to record bytes allocated. */
-static char *
-gmalloc (size)
- unsigned int size;
+static void *
+gmalloc (size_t size)
{
bytes_used += size;
return xmalloc (size);
}
+/* Cover function to xcalloc to record bytes allocated. */
+
+static void *
+gcalloc (size_t nelem, size_t elsize)
+{
+ bytes_used += nelem * elsize;
+ return xcalloc (nelem, elsize);
+}
+
/* Cover function to xrealloc.
We don't record the additional size since we don't know it.
It won't affect memory usage stats much anyway. */
-static char *
-grealloc (ptr, size)
- char *ptr;
- unsigned int size;
+static void *
+grealloc (void *ptr, size_t size)
{
return xrealloc (ptr, size);
}
-/* Cover function to obstack_alloc.
- We don't need to record the bytes allocated here since
- obstack_chunk_alloc is set to gmalloc. */
+/* Cover function to obstack_alloc. */
-static char *
-gcse_alloc (size)
- unsigned long size;
+static void *
+gcse_alloc (unsigned long size)
{
- return (char *) obstack_alloc (&gcse_obstack, size);
+ bytes_used += size;
+ return obstack_alloc (&gcse_obstack, size);
}
/* Allocate memory for the cuid mapping array,
This is called at the start of each pass. */
static void
-alloc_gcse_mem (f)
- rtx f;
+alloc_gcse_mem (rtx f)
{
- int i, n;
+ int i;
rtx insn;
/* Find the largest UID and create a mapping from UIDs to CUIDs.
and only apply to real insns. */
max_uid = get_max_uid ();
- n = (max_uid + 1) * sizeof (int);
- uid_cuid = (int *) gmalloc (n);
- memset ((char *) uid_cuid, 0, n);
+ uid_cuid = gcalloc (max_uid + 1, sizeof (int));
for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
{
if (INSN_P (insn))
/* Create a table mapping cuids to insns. */
max_cuid = i;
- n = (max_cuid + 1) * sizeof (rtx);
- cuid_insn = (rtx *) gmalloc (n);
- memset ((char *) cuid_insn, 0, n);
+ cuid_insn = gcalloc (max_cuid + 1, sizeof (rtx));
for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
if (INSN_P (insn))
CUID_INSN (i++) = insn;
reg_set_bitmap = BITMAP_XMALLOC ();
/* Allocate vars to track sets of regs, memory per block. */
- reg_set_in_block = (sbitmap *) sbitmap_vector_alloc (last_basic_block,
- max_gcse_regno);
+ reg_set_in_block = sbitmap_vector_alloc (last_basic_block, max_gcse_regno);
/* Allocate array to keep a list of insns which modify memory in each
basic block. */
- modify_mem_list = (rtx *) gmalloc (last_basic_block * sizeof (rtx));
- canon_modify_mem_list = (rtx *) gmalloc (last_basic_block * sizeof (rtx));
- memset ((char *) modify_mem_list, 0, last_basic_block * sizeof (rtx));
- memset ((char *) canon_modify_mem_list, 0, last_basic_block * sizeof (rtx));
+ modify_mem_list = gcalloc (last_basic_block, sizeof (rtx));
+ canon_modify_mem_list = gcalloc (last_basic_block, sizeof (rtx));
modify_mem_list_set = BITMAP_XMALLOC ();
canon_modify_mem_list_set = BITMAP_XMALLOC ();
}
/* Free memory allocated by alloc_gcse_mem. */
static void
-free_gcse_mem ()
+free_gcse_mem (void)
{
free (uid_cuid);
free (cuid_insn);
less space. */
static int
-get_bitmap_width (n, x, y)
- int n;
- int x;
- int y;
+get_bitmap_width (int n, int x, int y)
{
/* It's not really worth figuring out *exactly* how much memory will
be used by a particular choice. The important thing is to get
properties. If NULL, then it is not necessary to compute or record that
particular property.
- SETP controls which hash table to look at. If zero, this routine looks at
- the expr hash table; if nonzero this routine looks at the set hash table.
- Additionally, TRANSP is computed as ~TRANSP, since this is really cprop's
+ TABLE controls which hash table to look at. If it is set hash table,
+ additionally, TRANSP is computed as ~TRANSP, since this is really cprop's
ABSALTERED. */
static void
-compute_local_properties (transp, comp, antloc, setp)
- sbitmap *transp;
- sbitmap *comp;
- sbitmap *antloc;
- int setp;
+compute_local_properties (sbitmap *transp, sbitmap *comp, sbitmap *antloc, struct hash_table *table)
{
- unsigned int i, hash_table_size;
- struct expr **hash_table;
+ unsigned int i;
/* Initialize any bitmaps that were passed in. */
if (transp)
{
- if (setp)
+ if (table->set_p)
sbitmap_vector_zero (transp, last_basic_block);
else
sbitmap_vector_ones (transp, last_basic_block);
if (antloc)
sbitmap_vector_zero (antloc, last_basic_block);
- /* We use the same code for cprop, pre and hoisting. For cprop
- we care about the set hash table, for pre and hoisting we
- care about the expr hash table. */
- hash_table_size = setp ? set_hash_table_size : expr_hash_table_size;
- hash_table = setp ? set_hash_table : expr_hash_table;
-
- for (i = 0; i < hash_table_size; i++)
+ for (i = 0; i < table->size; i++)
{
struct expr *expr;
- for (expr = hash_table[i]; expr != NULL; expr = expr->next_same_hash)
+ for (expr = table->table[i]; expr != NULL; expr = expr->next_same_hash)
{
int indx = expr->bitmap_index;
struct occr *occr;
We start by assuming all are transparent [none are killed], and
then reset the bits for those that are. */
if (transp)
- compute_transp (expr->expr, indx, transp, setp);
+ compute_transp (expr->expr, indx, transp, table->set_p);
/* The occurrences recorded in antic_occr are exactly those that
- we want to set to non-zero in ANTLOC. */
+ we want to set to nonzero in ANTLOC. */
if (antloc)
for (occr = expr->antic_occr; occr != NULL; occr = occr->next)
{
}
/* The occurrences recorded in avail_occr are exactly those that
- we want to set to non-zero in COMP. */
+ we want to set to nonzero in COMP. */
if (comp)
for (occr = expr->avail_occr; occr != NULL; occr = occr->next)
{
static struct obstack reg_set_obstack;
static void
-alloc_reg_set_mem (n_regs)
- int n_regs;
+alloc_reg_set_mem (int n_regs)
{
- unsigned int n;
-
reg_set_table_size = n_regs + REG_SET_TABLE_SLOP;
- n = reg_set_table_size * sizeof (struct reg_set *);
- reg_set_table = (struct reg_set **) gmalloc (n);
- memset ((char *) reg_set_table, 0, n);
+ reg_set_table = gcalloc (reg_set_table_size, sizeof (struct reg_set *));
gcc_obstack_init (®_set_obstack);
}
static void
-free_reg_set_mem ()
+free_reg_set_mem (void)
{
free (reg_set_table);
obstack_free (®_set_obstack, NULL);
}
+/* An OLD_INSN that used to set REGNO was replaced by NEW_INSN.
+ Update the corresponding `reg_set_table' entry accordingly.
+ We assume that NEW_INSN is not already recorded in reg_set_table[regno]. */
+
+static void
+replace_one_set (int regno, rtx old_insn, rtx new_insn)
+{
+ struct reg_set *reg_info;
+ if (regno >= reg_set_table_size)
+ return;
+ for (reg_info = reg_set_table[regno]; reg_info; reg_info = reg_info->next)
+ if (reg_info->insn == old_insn)
+ {
+ reg_info->insn = new_insn;
+ break;
+ }
+}
+
/* Record REGNO in the reg_set table. */
static void
-record_one_set (regno, insn)
- int regno;
- rtx insn;
+record_one_set (int regno, rtx insn)
{
/* Allocate a new reg_set element and link it onto the list. */
struct reg_set *new_reg_info;
{
int new_size = regno + REG_SET_TABLE_SLOP;
- reg_set_table
- = (struct reg_set **) grealloc ((char *) reg_set_table,
- new_size * sizeof (struct reg_set *));
- memset ((char *) (reg_set_table + reg_set_table_size), 0,
+ reg_set_table = grealloc (reg_set_table,
+ new_size * sizeof (struct reg_set *));
+ memset (reg_set_table + reg_set_table_size, 0,
(new_size - reg_set_table_size) * sizeof (struct reg_set *));
reg_set_table_size = new_size;
}
- new_reg_info = (struct reg_set *) obstack_alloc (®_set_obstack,
- sizeof (struct reg_set));
+ new_reg_info = obstack_alloc (®_set_obstack, sizeof (struct reg_set));
bytes_used += sizeof (struct reg_set);
new_reg_info->insn = insn;
new_reg_info->next = reg_set_table[regno];
occurring. */
static void
-record_set_info (dest, setter, data)
- rtx dest, setter ATTRIBUTE_UNUSED;
- void *data;
+record_set_info (rtx dest, rtx setter ATTRIBUTE_UNUSED, void *data)
{
rtx record_set_insn = (rtx) data;
/* Scan the function and record each set of each pseudo-register.
This is called once, at the start of the gcse pass. See the comments for
- `reg_set_table' for further documenation. */
+ `reg_set_table' for further documentation. */
static void
-compute_sets (f)
- rtx f;
+compute_sets (rtx f)
{
rtx insn;
\f
/* Hash table support. */
-/* For each register, the cuid of the first/last insn in the block
- that set it, or -1 if not set. */
-#define NEVER_SET -1
-
struct reg_avail_info
{
basic_block last_bb;
static GTY(()) rtx test_insn;
static int
-want_to_gcse_p (x)
- rtx x;
+want_to_gcse_p (rtx x)
{
int num_clobbers = 0;
int icode;
case CONST_DOUBLE:
case CONST_VECTOR:
case CALL:
+ case CONSTANT_P_RTX:
return 0;
default:
&& (num_clobbers == 0 || ! added_clobbers_hard_reg_p (icode)));
}
-/* Return non-zero if the operands of expression X are unchanged from the
+/* Return nonzero if the operands of expression X are unchanged from the
start of INSN's basic block up to but not including INSN (if AVAIL_P == 0),
or from INSN to the end of INSN's basic block (if AVAIL_P != 0). */
static int
-oprs_unchanged_p (x, insn, avail_p)
- rtx x, insn;
- int avail_p;
+oprs_unchanged_p (rtx x, rtx insn, int avail_p)
{
int i, j;
enum rtx_code code;
gcse_mems_conflict_p to a nonzero value. */
static void
-mems_conflict_for_gcse_p (dest, setter, data)
- rtx dest, setter ATTRIBUTE_UNUSED;
- void *data ATTRIBUTE_UNUSED;
+mems_conflict_for_gcse_p (rtx dest, rtx setter ATTRIBUTE_UNUSED,
+ void *data ATTRIBUTE_UNUSED)
{
while (GET_CODE (dest) == SUBREG
|| GET_CODE (dest) == ZERO_EXTRACT
/* If we are setting a MEM in our list of specially recognized MEMs,
don't mark as killed this time. */
- if (dest == gcse_mem_operand && pre_ldst_mems != NULL)
+ if (expr_equiv_p (dest, gcse_mem_operand) && pre_ldst_mems != NULL)
{
if (!find_rtx_in_ldst (dest))
gcse_mems_conflict_p = 1;
AVAIL_P to 0. */
static int
-load_killed_in_block_p (bb, uid_limit, x, avail_p)
- basic_block bb;
- int uid_limit;
- rtx x;
- int avail_p;
+load_killed_in_block_p (basic_block bb, int uid_limit, rtx x, int avail_p)
{
rtx list_entry = modify_mem_list[bb->index];
while (list_entry)
return 0;
}
-/* Return non-zero if the operands of expression X are unchanged from
+/* Return nonzero if the operands of expression X are unchanged from
the start of INSN's basic block up to but not including INSN. */
static int
-oprs_anticipatable_p (x, insn)
- rtx x, insn;
+oprs_anticipatable_p (rtx x, rtx insn)
{
return oprs_unchanged_p (x, insn, 0);
}
-/* Return non-zero if the operands of expression X are unchanged from
+/* Return nonzero if the operands of expression X are unchanged from
INSN to the end of INSN's basic block. */
static int
-oprs_available_p (x, insn)
- rtx x, insn;
+oprs_available_p (rtx x, rtx insn)
{
return oprs_unchanged_p (x, insn, 1);
}
MODE is only used if X is a CONST_INT. DO_NOT_RECORD_P is a boolean
indicating if a volatile operand is found or if the expression contains
- something we don't want to insert in the table.
+ something we don't want to insert in the table. HASH_TABLE_SIZE is
+ the current size of the hash table to be probed.
??? One might want to merge this with canon_hash. Later. */
static unsigned int
-hash_expr (x, mode, do_not_record_p, hash_table_size)
- rtx x;
- enum machine_mode mode;
- int *do_not_record_p;
- int hash_table_size;
+hash_expr (rtx x, enum machine_mode mode, int *do_not_record_p,
+ int hash_table_size)
{
unsigned int hash;
/* Hash a string. Just add its bytes up. */
static inline unsigned
-hash_string_1 (ps)
- const char *ps;
+hash_string_1 (const char *ps)
{
unsigned hash = 0;
const unsigned char *p = (const unsigned char *) ps;
/* Subroutine of hash_expr to do the actual work. */
static unsigned int
-hash_expr_1 (x, mode, do_not_record_p)
- rtx x;
- enum machine_mode mode;
- int *do_not_record_p;
+hash_expr_1 (rtx x, enum machine_mode mode, int *do_not_record_p)
{
int i, j;
unsigned hash = 0;
const char *fmt;
/* Used to turn recursion into iteration. We can't rely on GCC's
- tail-recursion eliminatio since we need to keep accumulating values
+ tail-recursion elimination since we need to keep accumulating values
in HASH. */
if (x == 0)
??? May need to make things more elaborate. Later, as necessary. */
static unsigned int
-hash_set (regno, hash_table_size)
- int regno;
- int hash_table_size;
+hash_set (int regno, int hash_table_size)
{
unsigned int hash;
return hash % hash_table_size;
}
-/* Return non-zero if exp1 is equivalent to exp2.
+/* Return nonzero if exp1 is equivalent to exp2.
??? Borrowed from cse.c. Might want to remerge with cse.c. Later. */
static int
-expr_equiv_p (x, y)
- rtx x, y;
+expr_equiv_p (rtx x, rtx y)
{
int i, j;
enum rtx_code code;
return 1;
if (x == 0 || y == 0)
- return x == y;
+ return 0;
code = GET_CODE (x);
if (code != GET_CODE (y))
{
case PC:
case CC0:
- return x == y;
-
case CONST_INT:
- return INTVAL (x) == INTVAL (y);
+ return 0;
case LABEL_REF:
return XEXP (x, 0) == XEXP (y, 0);
due to it being set with the different alias set. */
if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
return 0;
+
+ /* A volatile mem should not be considered equivalent to any other. */
+ if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
+ return 0;
break;
/* For commutative operations, check both orders. */
return 1;
}
-/* Insert expression X in INSN in the hash table.
+/* Insert expression X in INSN in the hash TABLE.
If it is already present, record it as the last occurrence in INSN's
basic block.
MODE is the mode of the value X is being stored into.
It is only used if X is a CONST_INT.
- ANTIC_P is non-zero if X is an anticipatable expression.
- AVAIL_P is non-zero if X is an available expression. */
+ ANTIC_P is nonzero if X is an anticipatable expression.
+ AVAIL_P is nonzero if X is an available expression. */
static void
-insert_expr_in_table (x, mode, insn, antic_p, avail_p)
- rtx x;
- enum machine_mode mode;
- rtx insn;
- int antic_p, avail_p;
+insert_expr_in_table (rtx x, enum machine_mode mode, rtx insn, int antic_p,
+ int avail_p, struct hash_table *table)
{
int found, do_not_record_p;
unsigned int hash;
struct occr *antic_occr, *avail_occr;
struct occr *last_occr = NULL;
- hash = hash_expr (x, mode, &do_not_record_p, expr_hash_table_size);
+ hash = hash_expr (x, mode, &do_not_record_p, table->size);
/* Do not insert expression in table if it contains volatile operands,
or if hash_expr determines the expression is something we don't want
if (do_not_record_p)
return;
- cur_expr = expr_hash_table[hash];
+ cur_expr = table->table[hash];
found = 0;
while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x)))
if (! found)
{
- cur_expr = (struct expr *) gcse_alloc (sizeof (struct expr));
+ cur_expr = gcse_alloc (sizeof (struct expr));
bytes_used += sizeof (struct expr);
- if (expr_hash_table[hash] == NULL)
+ if (table->table[hash] == NULL)
/* This is the first pattern that hashed to this index. */
- expr_hash_table[hash] = cur_expr;
+ table->table[hash] = cur_expr;
else
/* Add EXPR to end of this hash chain. */
last_expr->next_same_hash = cur_expr;
/* Set the fields of the expr element. */
cur_expr->expr = x;
- cur_expr->bitmap_index = n_exprs++;
+ cur_expr->bitmap_index = table->n_elems++;
cur_expr->next_same_hash = NULL;
cur_expr->antic_occr = NULL;
cur_expr->avail_occr = NULL;
else
{
/* First occurrence of this expression in this basic block. */
- antic_occr = (struct occr *) gcse_alloc (sizeof (struct occr));
+ antic_occr = gcse_alloc (sizeof (struct occr));
bytes_used += sizeof (struct occr);
/* First occurrence of this expression in any block? */
if (cur_expr->antic_occr == NULL)
else
{
/* First occurrence of this expression in this basic block. */
- avail_occr = (struct occr *) gcse_alloc (sizeof (struct occr));
+ avail_occr = gcse_alloc (sizeof (struct occr));
bytes_used += sizeof (struct occr);
/* First occurrence of this expression in any block? */
basic block. */
static void
-insert_set_in_table (x, insn)
- rtx x;
- rtx insn;
+insert_set_in_table (rtx x, rtx insn, struct hash_table *table)
{
int found;
unsigned int hash;
|| GET_CODE (SET_DEST (x)) != REG)
abort ();
- hash = hash_set (REGNO (SET_DEST (x)), set_hash_table_size);
+ hash = hash_set (REGNO (SET_DEST (x)), table->size);
- cur_expr = set_hash_table[hash];
+ cur_expr = table->table[hash];
found = 0;
while (cur_expr && 0 == (found = expr_equiv_p (cur_expr->expr, x)))
if (! found)
{
- cur_expr = (struct expr *) gcse_alloc (sizeof (struct expr));
+ cur_expr = gcse_alloc (sizeof (struct expr));
bytes_used += sizeof (struct expr);
- if (set_hash_table[hash] == NULL)
+ if (table->table[hash] == NULL)
/* This is the first pattern that hashed to this index. */
- set_hash_table[hash] = cur_expr;
+ table->table[hash] = cur_expr;
else
/* Add EXPR to end of this hash chain. */
last_expr->next_same_hash = cur_expr;
We must copy X because it can be modified when copy propagation is
performed on its operands. */
cur_expr->expr = copy_rtx (x);
- cur_expr->bitmap_index = n_sets++;
+ cur_expr->bitmap_index = table->n_elems++;
cur_expr->next_same_hash = NULL;
cur_expr->antic_occr = NULL;
cur_expr->avail_occr = NULL;
else
{
/* First occurrence of this expression in this basic block. */
- cur_occr = (struct occr *) gcse_alloc (sizeof (struct occr));
+ cur_occr = gcse_alloc (sizeof (struct occr));
bytes_used += sizeof (struct occr);
/* First occurrence of this expression in any block? */
}
}
-/* Scan pattern PAT of INSN and add an entry to the hash table. If SET_P is
- non-zero, this is for the assignment hash table, otherwise it is for the
- expression hash table. */
+/* Determine whether the rtx X should be treated as a constant for
+ the purposes of GCSE's constant propagation. */
+
+static bool
+gcse_constant_p (rtx x)
+{
+ /* Consider a COMPARE of two integers constant. */
+ if (GET_CODE (x) == COMPARE
+ && GET_CODE (XEXP (x, 0)) == CONST_INT
+ && GET_CODE (XEXP (x, 1)) == CONST_INT)
+ return true;
+
+
+ /* Consider a COMPARE of the same registers is a constant
+ if they are not floating point registers. */
+ if (GET_CODE(x) == COMPARE
+ && GET_CODE (XEXP (x, 0)) == REG
+ && GET_CODE (XEXP (x, 1)) == REG
+ && REGNO (XEXP (x, 0)) == REGNO (XEXP (x, 1))
+ && ! FLOAT_MODE_P (GET_MODE (XEXP (x, 0)))
+ && ! FLOAT_MODE_P (GET_MODE (XEXP (x, 1))))
+ return true;
+
+ if (GET_CODE (x) == CONSTANT_P_RTX)
+ return false;
+
+ return CONSTANT_P (x);
+}
+
+/* Scan pattern PAT of INSN and add an entry to the hash TABLE (set or
+ expression one). */
static void
-hash_scan_set (pat, insn, set_p)
- rtx pat, insn;
- int set_p;
+hash_scan_set (rtx pat, rtx insn, struct hash_table *table)
{
rtx src = SET_SRC (pat);
rtx dest = SET_DEST (pat);
rtx note;
if (GET_CODE (src) == CALL)
- hash_scan_call (src, insn);
+ hash_scan_call (src, insn, table);
else if (GET_CODE (dest) == REG)
{
/* If this is a single set and we are doing constant propagation,
see if a REG_NOTE shows this equivalent to a constant. */
- if (set_p && (note = find_reg_equal_equiv_note (insn)) != 0
- && CONSTANT_P (XEXP (note, 0)))
+ if (table->set_p && (note = find_reg_equal_equiv_note (insn)) != 0
+ && gcse_constant_p (XEXP (note, 0)))
src = XEXP (note, 0), pat = gen_rtx_SET (VOIDmode, dest, src);
/* Only record sets of pseudo-regs in the hash table. */
- if (! set_p
+ if (! table->set_p
&& regno >= FIRST_PSEUDO_REGISTER
/* Don't GCSE something if we can't do a reg/reg copy. */
- && can_copy_p [GET_MODE (dest)]
+ && can_copy_p (GET_MODE (dest))
/* GCSE commonly inserts instruction after the insn. We can't
do that easily for EH_REGION notes so disable GCSE on these
for now. */
int avail_p = (oprs_available_p (src, insn)
&& ! JUMP_P (insn));
- insert_expr_in_table (src, GET_MODE (dest), insn, antic_p, avail_p);
+ insert_expr_in_table (src, GET_MODE (dest), insn, antic_p, avail_p, table);
}
/* Record sets for constant/copy propagation. */
- else if (set_p
+ else if (table->set_p
&& regno >= FIRST_PSEUDO_REGISTER
&& ((GET_CODE (src) == REG
&& REGNO (src) >= FIRST_PSEUDO_REGISTER
- && can_copy_p [GET_MODE (dest)]
+ && can_copy_p (GET_MODE (dest))
&& REGNO (src) != regno)
- || CONSTANT_P (src))
+ || gcse_constant_p (src))
/* A copy is not available if its src or dest is subsequently
modified. Here we want to search from INSN+1 on, but
oprs_available_p searches from INSN on. */
- && (insn == BLOCK_END (BLOCK_NUM (insn))
+ && (insn == BB_END (BLOCK_FOR_INSN (insn))
|| ((tmp = next_nonnote_insn (insn)) != NULL_RTX
&& oprs_available_p (pat, tmp))))
- insert_set_in_table (pat, insn);
+ insert_set_in_table (pat, insn, table);
}
+ /* In case of store we want to consider the memory value as available in
+ the REG stored in that memory. This makes it possible to remove
+ redundant loads from due to stores to the same location. */
+ else if (flag_gcse_las && GET_CODE (src) == REG && GET_CODE (dest) == MEM)
+ {
+ unsigned int regno = REGNO (src);
+
+ /* Do not do this for constant/copy propagation. */
+ if (! table->set_p
+ /* Only record sets of pseudo-regs in the hash table. */
+ && regno >= FIRST_PSEUDO_REGISTER
+ /* Don't GCSE something if we can't do a reg/reg copy. */
+ && can_copy_p (GET_MODE (src))
+ /* GCSE commonly inserts instruction after the insn. We can't
+ do that easily for EH_REGION notes so disable GCSE on these
+ for now. */
+ && ! find_reg_note (insn, REG_EH_REGION, NULL_RTX)
+ /* Is SET_DEST something we want to gcse? */
+ && want_to_gcse_p (dest)
+ /* Don't CSE a nop. */
+ && ! set_noop_p (pat)
+ /* Don't GCSE if it has attached REG_EQUIV note.
+ At this point this only function parameters should have
+ REG_EQUIV notes and if the argument slot is used somewhere
+ explicitly, it means address of parameter has been taken,
+ so we should not extend the lifetime of the pseudo. */
+ && ((note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) == 0
+ || GET_CODE (XEXP (note, 0)) != MEM))
+ {
+ /* Stores are never anticipatable. */
+ int antic_p = 0;
+ /* An expression is not available if its operands are
+ subsequently modified, including this insn. It's also not
+ available if this is a branch, because we can't insert
+ a set after the branch. */
+ int avail_p = oprs_available_p (dest, insn)
+ && ! JUMP_P (insn);
+
+ /* Record the memory expression (DEST) in the hash table. */
+ insert_expr_in_table (dest, GET_MODE (dest), insn,
+ antic_p, avail_p, table);
+ }
+ }
}
static void
-hash_scan_clobber (x, insn)
- rtx x ATTRIBUTE_UNUSED, insn ATTRIBUTE_UNUSED;
+hash_scan_clobber (rtx x ATTRIBUTE_UNUSED, rtx insn ATTRIBUTE_UNUSED,
+ struct hash_table *table ATTRIBUTE_UNUSED)
{
/* Currently nothing to do. */
}
static void
-hash_scan_call (x, insn)
- rtx x ATTRIBUTE_UNUSED, insn ATTRIBUTE_UNUSED;
+hash_scan_call (rtx x ATTRIBUTE_UNUSED, rtx insn ATTRIBUTE_UNUSED,
+ struct hash_table *table ATTRIBUTE_UNUSED)
{
/* Currently nothing to do. */
}
that isn't dealt with right now. The trick is handling the CLOBBERs that
are also in the PARALLEL. Later.
- If SET_P is non-zero, this is for the assignment hash table,
+ If SET_P is nonzero, this is for the assignment hash table,
otherwise it is for the expression hash table.
If IN_LIBCALL_BLOCK nonzero, we are in a libcall block, and should
not record any expressions. */
static void
-hash_scan_insn (insn, set_p, in_libcall_block)
- rtx insn;
- int set_p;
- int in_libcall_block;
+hash_scan_insn (rtx insn, struct hash_table *table, int in_libcall_block)
{
rtx pat = PATTERN (insn);
int i;
what's been modified. */
if (GET_CODE (pat) == SET)
- hash_scan_set (pat, insn, set_p);
+ hash_scan_set (pat, insn, table);
else if (GET_CODE (pat) == PARALLEL)
for (i = 0; i < XVECLEN (pat, 0); i++)
{
rtx x = XVECEXP (pat, 0, i);
if (GET_CODE (x) == SET)
- hash_scan_set (x, insn, set_p);
+ hash_scan_set (x, insn, table);
else if (GET_CODE (x) == CLOBBER)
- hash_scan_clobber (x, insn);
+ hash_scan_clobber (x, insn, table);
else if (GET_CODE (x) == CALL)
- hash_scan_call (x, insn);
+ hash_scan_call (x, insn, table);
}
else if (GET_CODE (pat) == CLOBBER)
- hash_scan_clobber (pat, insn);
+ hash_scan_clobber (pat, insn, table);
else if (GET_CODE (pat) == CALL)
- hash_scan_call (pat, insn);
+ hash_scan_call (pat, insn, table);
}
static void
-dump_hash_table (file, name, table, table_size, total_size)
- FILE *file;
- const char *name;
- struct expr **table;
- int table_size, total_size;
+dump_hash_table (FILE *file, const char *name, struct hash_table *table)
{
int i;
/* Flattened out table, so it's printed in proper order. */
unsigned int *hash_val;
struct expr *expr;
- flat_table
- = (struct expr **) xcalloc (total_size, sizeof (struct expr *));
- hash_val = (unsigned int *) xmalloc (total_size * sizeof (unsigned int));
+ flat_table = xcalloc (table->n_elems, sizeof (struct expr *));
+ hash_val = xmalloc (table->n_elems * sizeof (unsigned int));
- for (i = 0; i < table_size; i++)
- for (expr = table[i]; expr != NULL; expr = expr->next_same_hash)
+ for (i = 0; i < (int) table->size; i++)
+ for (expr = table->table[i]; expr != NULL; expr = expr->next_same_hash)
{
flat_table[expr->bitmap_index] = expr;
hash_val[expr->bitmap_index] = i;
}
fprintf (file, "%s hash table (%d buckets, %d entries)\n",
- name, table_size, total_size);
+ name, table->size, table->n_elems);
- for (i = 0; i < total_size; i++)
+ for (i = 0; i < (int) table->n_elems; i++)
if (flat_table[i] != 0)
{
expr = flat_table[i];
and is used to compute "transparency". */
static void
-record_last_reg_set_info (insn, regno)
- rtx insn;
- int regno;
+record_last_reg_set_info (rtx insn, int regno)
{
struct reg_avail_info *info = ®_avail_info[regno];
int cuid = INSN_CUID (insn);
taken off pairwise. */
static void
-canon_list_insert (dest, unused1, v_insn)
- rtx dest ATTRIBUTE_UNUSED;
- rtx unused1 ATTRIBUTE_UNUSED;
- void * v_insn;
+canon_list_insert (rtx dest ATTRIBUTE_UNUSED, rtx unused1 ATTRIBUTE_UNUSED,
+ void * v_insn)
{
rtx dest_addr, insn;
int bb;
a CALL_INSN). We merely need to record which insns modify memory. */
static void
-record_last_mem_set_info (insn)
- rtx insn;
+record_last_mem_set_info (rtx insn)
{
int bb = BLOCK_NUM (insn);
the SET is taking place. */
static void
-record_last_set_info (dest, setter, data)
- rtx dest, setter ATTRIBUTE_UNUSED;
- void *data;
+record_last_set_info (rtx dest, rtx setter ATTRIBUTE_UNUSED, void *data)
{
rtx last_set_insn = (rtx) data;
Currently src must be a pseudo-reg or a const_int.
- F is the first insn.
- SET_P is non-zero for computing the assignment hash table. */
+ TABLE is the table computed. */
static void
-compute_hash_table (set_p)
- int set_p;
+compute_hash_table_work (struct hash_table *table)
{
unsigned int i;
/* re-Cache any INSN_LIST nodes we have allocated. */
clear_modify_mem_tables ();
/* Some working arrays used to track first and last set in each block. */
- reg_avail_info = (struct reg_avail_info*)
- gmalloc (max_gcse_regno * sizeof (struct reg_avail_info));
+ reg_avail_info = gmalloc (max_gcse_regno * sizeof (struct reg_avail_info));
for (i = 0; i < max_gcse_regno; ++i)
reg_avail_info[i].last_bb = NULL;
??? hard-reg reg_set_in_block computation
could be moved to compute_sets since they currently don't change. */
- for (insn = current_bb->head;
- insn && insn != NEXT_INSN (current_bb->end);
+ for (insn = BB_HEAD (current_bb);
+ insn && insn != NEXT_INSN (BB_END (current_bb));
insn = NEXT_INSN (insn))
{
if (! INSN_P (insn))
note_stores (PATTERN (insn), record_last_set_info, insn);
}
+ /* Insert implicit sets in the hash table. */
+ if (table->set_p
+ && implicit_sets[current_bb->index] != NULL_RTX)
+ hash_scan_set (implicit_sets[current_bb->index],
+ BB_HEAD (current_bb), table);
+
/* The next pass builds the hash table. */
- for (insn = current_bb->head, in_libcall_block = 0;
- insn && insn != NEXT_INSN (current_bb->end);
+ for (insn = BB_HEAD (current_bb), in_libcall_block = 0;
+ insn && insn != NEXT_INSN (BB_END (current_bb));
insn = NEXT_INSN (insn))
if (INSN_P (insn))
{
if (find_reg_note (insn, REG_LIBCALL, NULL_RTX))
in_libcall_block = 1;
- else if (set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX))
+ else if (table->set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX))
in_libcall_block = 0;
- hash_scan_insn (insn, set_p, in_libcall_block);
- if (!set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX))
+ hash_scan_insn (insn, table, in_libcall_block);
+ if (!table->set_p && find_reg_note (insn, REG_RETVAL, NULL_RTX))
in_libcall_block = 0;
}
}
reg_avail_info = NULL;
}
-/* Allocate space for the set hash table.
- N_INSNS is the number of instructions in the function.
- It is used to determine the number of buckets to use. */
-
-static void
-alloc_set_hash_table (n_insns)
- int n_insns;
-{
- int n;
-
- set_hash_table_size = n_insns / 4;
- if (set_hash_table_size < 11)
- set_hash_table_size = 11;
-
- /* Attempt to maintain efficient use of hash table.
- Making it an odd number is simplest for now.
- ??? Later take some measurements. */
- set_hash_table_size |= 1;
- n = set_hash_table_size * sizeof (struct expr *);
- set_hash_table = (struct expr **) gmalloc (n);
-}
-
-/* Free things allocated by alloc_set_hash_table. */
-
-static void
-free_set_hash_table ()
-{
- free (set_hash_table);
-}
-
-/* Compute the hash table for doing copy/const propagation. */
-
-static void
-compute_set_hash_table ()
-{
- /* Initialize count of number of entries in hash table. */
- n_sets = 0;
- memset ((char *) set_hash_table, 0,
- set_hash_table_size * sizeof (struct expr *));
-
- compute_hash_table (1);
-}
-
-/* Allocate space for the expression hash table.
+/* Allocate space for the set/expr hash TABLE.
N_INSNS is the number of instructions in the function.
- It is used to determine the number of buckets to use. */
+ It is used to determine the number of buckets to use.
+ SET_P determines whether set or expression table will
+ be created. */
static void
-alloc_expr_hash_table (n_insns)
- unsigned int n_insns;
+alloc_hash_table (int n_insns, struct hash_table *table, int set_p)
{
int n;
- expr_hash_table_size = n_insns / 2;
- /* Make sure the amount is usable. */
- if (expr_hash_table_size < 11)
- expr_hash_table_size = 11;
+ table->size = n_insns / 4;
+ if (table->size < 11)
+ table->size = 11;
/* Attempt to maintain efficient use of hash table.
Making it an odd number is simplest for now.
??? Later take some measurements. */
- expr_hash_table_size |= 1;
- n = expr_hash_table_size * sizeof (struct expr *);
- expr_hash_table = (struct expr **) gmalloc (n);
+ table->size |= 1;
+ n = table->size * sizeof (struct expr *);
+ table->table = gmalloc (n);
+ table->set_p = set_p;
}
-/* Free things allocated by alloc_expr_hash_table. */
+/* Free things allocated by alloc_hash_table. */
static void
-free_expr_hash_table ()
+free_hash_table (struct hash_table *table)
{
- free (expr_hash_table);
+ free (table->table);
}
-/* Compute the hash table for doing GCSE. */
+/* Compute the hash TABLE for doing copy/const propagation or
+ expression hash table. */
static void
-compute_expr_hash_table ()
+compute_hash_table (struct hash_table *table)
{
/* Initialize count of number of entries in hash table. */
- n_exprs = 0;
- memset ((char *) expr_hash_table, 0,
- expr_hash_table_size * sizeof (struct expr *));
+ table->n_elems = 0;
+ memset (table->table, 0, table->size * sizeof (struct expr *));
- compute_hash_table (0);
+ compute_hash_table_work (table);
}
\f
/* Expression tracking support. */
-/* Lookup pattern PAT in the expression table.
+/* Lookup pattern PAT in the expression TABLE.
The result is a pointer to the table entry, or NULL if not found. */
static struct expr *
-lookup_expr (pat)
- rtx pat;
+lookup_expr (rtx pat, struct hash_table *table)
{
int do_not_record_p;
unsigned int hash = hash_expr (pat, GET_MODE (pat), &do_not_record_p,
- expr_hash_table_size);
+ table->size);
struct expr *expr;
if (do_not_record_p)
return NULL;
- expr = expr_hash_table[hash];
+ expr = table->table[hash];
while (expr && ! expr_equiv_p (expr->expr, pat))
expr = expr->next_same_hash;
return expr;
}
-/* Lookup REGNO in the set table. If PAT is non-NULL look for the entry that
- matches it, otherwise return the first entry for REGNO. The result is a
- pointer to the table entry, or NULL if not found. */
+/* Lookup REGNO in the set TABLE. The result is a pointer to the
+ table entry, or NULL if not found. */
static struct expr *
-lookup_set (regno, pat)
- unsigned int regno;
- rtx pat;
+lookup_set (unsigned int regno, struct hash_table *table)
{
- unsigned int hash = hash_set (regno, set_hash_table_size);
+ unsigned int hash = hash_set (regno, table->size);
struct expr *expr;
- expr = set_hash_table[hash];
+ expr = table->table[hash];
- if (pat)
- {
- while (expr && ! expr_equiv_p (expr->expr, pat))
- expr = expr->next_same_hash;
- }
- else
- {
- while (expr && REGNO (SET_DEST (expr->expr)) != regno)
- expr = expr->next_same_hash;
- }
+ while (expr && REGNO (SET_DEST (expr->expr)) != regno)
+ expr = expr->next_same_hash;
return expr;
}
/* Return the next entry for REGNO in list EXPR. */
static struct expr *
-next_set (regno, expr)
- unsigned int regno;
- struct expr *expr;
+next_set (unsigned int regno, struct expr *expr)
{
do
expr = expr->next_same_hash;
types may be mixed. */
static void
-free_insn_expr_list_list (listp)
- rtx *listp;
+free_insn_expr_list_list (rtx *listp)
{
rtx list, next;
/* Clear canon_modify_mem_list and modify_mem_list tables. */
static void
-clear_modify_mem_tables ()
+clear_modify_mem_tables (void)
{
int i;
/* Release memory used by modify_mem_list_set and canon_modify_mem_list_set. */
static void
-free_modify_mem_tables ()
+free_modify_mem_tables (void)
{
clear_modify_mem_tables ();
free (modify_mem_list);
start of the block]. */
static void
-reset_opr_set_tables ()
+reset_opr_set_tables (void)
{
/* Maintain a bitmap of which regs have been set since beginning of
the block. */
clear_modify_mem_tables ();
}
-/* Return non-zero if the operands of X are not set before INSN in
+/* Return nonzero if the operands of X are not set before INSN in
INSN's basic block. */
static int
-oprs_not_set_p (x, insn)
- rtx x, insn;
+oprs_not_set_p (rtx x, rtx insn)
{
int i, j;
enum rtx_code code;
/* Mark things set by a CALL. */
static void
-mark_call (insn)
- rtx insn;
+mark_call (rtx insn)
{
if (! CONST_OR_PURE_CALL_P (insn))
record_last_mem_set_info (insn);
/* Mark things set by a SET. */
static void
-mark_set (pat, insn)
- rtx pat, insn;
+mark_set (rtx pat, rtx insn)
{
rtx dest = SET_DEST (pat);
/* Record things set by a CLOBBER. */
static void
-mark_clobber (pat, insn)
- rtx pat, insn;
+mark_clobber (rtx pat, rtx insn)
{
rtx clob = XEXP (pat, 0);
This data is used by oprs_not_set_p. */
static void
-mark_oprs_set (insn)
- rtx insn;
+mark_oprs_set (rtx insn)
{
rtx pat = PATTERN (insn);
int i;
/* Allocate reaching def variables. */
static void
-alloc_rd_mem (n_blocks, n_insns)
- int n_blocks, n_insns;
+alloc_rd_mem (int n_blocks, int n_insns)
{
- rd_kill = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns);
+ rd_kill = sbitmap_vector_alloc (n_blocks, n_insns);
sbitmap_vector_zero (rd_kill, n_blocks);
- rd_gen = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns);
+ rd_gen = sbitmap_vector_alloc (n_blocks, n_insns);
sbitmap_vector_zero (rd_gen, n_blocks);
- reaching_defs = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns);
+ reaching_defs = sbitmap_vector_alloc (n_blocks, n_insns);
sbitmap_vector_zero (reaching_defs, n_blocks);
- rd_out = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_insns);
+ rd_out = sbitmap_vector_alloc (n_blocks, n_insns);
sbitmap_vector_zero (rd_out, n_blocks);
}
/* Free reaching def variables. */
static void
-free_rd_mem ()
+free_rd_mem (void)
{
sbitmap_vector_free (rd_kill);
sbitmap_vector_free (rd_gen);
/* Add INSN to the kills of BB. REGNO, set in BB, is killed by INSN. */
static void
-handle_rd_kill_set (insn, regno, bb)
- rtx insn;
- int regno;
- basic_block bb;
+handle_rd_kill_set (rtx insn, int regno, basic_block bb)
{
struct reg_set *this_reg;
/* Compute the set of kill's for reaching definitions. */
static void
-compute_kill_rd ()
+compute_kill_rd (void)
{
int cuid;
unsigned int regno;
expressions but applied to the gens and kills of reaching definitions. */
static void
-compute_rd ()
+compute_rd (void)
{
int changed, passes;
basic_block bb;
/* Allocate memory for available expression computation. */
static void
-alloc_avail_expr_mem (n_blocks, n_exprs)
- int n_blocks, n_exprs;
+alloc_avail_expr_mem (int n_blocks, int n_exprs)
{
- ae_kill = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs);
+ ae_kill = sbitmap_vector_alloc (n_blocks, n_exprs);
sbitmap_vector_zero (ae_kill, n_blocks);
- ae_gen = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs);
+ ae_gen = sbitmap_vector_alloc (n_blocks, n_exprs);
sbitmap_vector_zero (ae_gen, n_blocks);
- ae_in = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs);
+ ae_in = sbitmap_vector_alloc (n_blocks, n_exprs);
sbitmap_vector_zero (ae_in, n_blocks);
- ae_out = (sbitmap *) sbitmap_vector_alloc (n_blocks, n_exprs);
+ ae_out = sbitmap_vector_alloc (n_blocks, n_exprs);
sbitmap_vector_zero (ae_out, n_blocks);
}
static void
-free_avail_expr_mem ()
+free_avail_expr_mem (void)
{
sbitmap_vector_free (ae_kill);
sbitmap_vector_free (ae_gen);
/* Compute the set of available expressions generated in each basic block. */
static void
-compute_ae_gen ()
+compute_ae_gen (struct hash_table *expr_hash_table)
{
unsigned int i;
struct expr *expr;
This is all we have to do because an expression is not recorded if it
is not available, and the only expressions we want to work with are the
ones that are recorded. */
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr != 0; expr = expr->next_same_hash)
+ for (i = 0; i < expr_hash_table->size; i++)
+ for (expr = expr_hash_table->table[i]; expr != 0; expr = expr->next_same_hash)
for (occr = expr->avail_occr; occr != 0; occr = occr->next)
SET_BIT (ae_gen[BLOCK_NUM (occr->insn)], expr->bitmap_index);
}
-/* Return non-zero if expression X is killed in BB. */
+/* Return nonzero if expression X is killed in BB. */
static int
-expr_killed_p (x, bb)
- rtx x;
- basic_block bb;
+expr_killed_p (rtx x, basic_block bb)
{
int i, j;
enum rtx_code code;
/* Compute the set of available expressions killed in each basic block. */
static void
-compute_ae_kill (ae_gen, ae_kill)
- sbitmap *ae_gen, *ae_kill;
+compute_ae_kill (sbitmap *ae_gen, sbitmap *ae_kill,
+ struct hash_table *expr_hash_table)
{
basic_block bb;
unsigned int i;
struct expr *expr;
FOR_EACH_BB (bb)
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr; expr = expr->next_same_hash)
+ for (i = 0; i < expr_hash_table->size; i++)
+ for (expr = expr_hash_table->table[i]; expr; expr = expr->next_same_hash)
{
/* Skip EXPR if generated in this block. */
if (TEST_BIT (ae_gen[bb->index], expr->bitmap_index))
\f
/* Actually perform the Classic GCSE optimizations. */
-/* Return non-zero if occurrence OCCR of expression EXPR reaches block BB.
+/* Return nonzero if occurrence OCCR of expression EXPR reaches block BB.
- CHECK_SELF_LOOP is non-zero if we should consider a block reaching itself
+ CHECK_SELF_LOOP is nonzero if we should consider a block reaching itself
as a positive reach. We want to do this when there are two computations
of the expression in the block.
the closest such expression. */
static int
-expr_reaches_here_p_work (occr, expr, bb, check_self_loop, visited)
- struct occr *occr;
- struct expr *expr;
- basic_block bb;
- int check_self_loop;
- char *visited;
+expr_reaches_here_p_work (struct occr *occr, struct expr *expr,
+ basic_block bb, int check_self_loop, char *visited)
{
edge pred;
memory allocated for that function is returned. */
static int
-expr_reaches_here_p (occr, expr, bb, check_self_loop)
- struct occr *occr;
- struct expr *expr;
- basic_block bb;
- int check_self_loop;
+expr_reaches_here_p (struct occr *occr, struct expr *expr, basic_block bb,
+ int check_self_loop)
{
int rval;
- char *visited = (char *) xcalloc (last_basic_block, 1);
+ char *visited = xcalloc (last_basic_block, 1);
rval = expr_reaches_here_p_work (occr, expr, bb, check_self_loop, visited);
Called only by handle_avail_expr. */
static rtx
-computing_insn (expr, insn)
- struct expr *expr;
- rtx insn;
+computing_insn (struct expr *expr, rtx insn)
{
basic_block bb = BLOCK_FOR_INSN (insn);
}
}
-/* Return non-zero if the definition in DEF_INSN can reach INSN.
+/* Return nonzero if the definition in DEF_INSN can reach INSN.
Only called by can_disregard_other_sets. */
static int
-def_reaches_here_p (insn, def_insn)
- rtx insn, def_insn;
+def_reaches_here_p (rtx insn, rtx def_insn)
{
rtx reg;
return 0;
}
-/* Return non-zero if *ADDR_THIS_REG can only have one value at INSN. The
+/* Return nonzero if *ADDR_THIS_REG can only have one value at INSN. The
value returned is the number of definitions that reach INSN. Returning a
value of zero means that [maybe] more than one definition reaches INSN and
the caller can't perform whatever optimization it is trying. i.e. it is
always safe to return zero. */
static int
-can_disregard_other_sets (addr_this_reg, insn, for_combine)
- struct reg_set **addr_this_reg;
- rtx insn;
- int for_combine;
+can_disregard_other_sets (struct reg_set **addr_this_reg, rtx insn, int for_combine)
{
int number_of_reaching_defs = 0;
struct reg_set *this_reg;
/* Expression computed by insn is available and the substitution is legal,
so try to perform the substitution.
- The result is non-zero if any changes were made. */
+ The result is nonzero if any changes were made. */
static int
-handle_avail_expr (insn, expr)
- rtx insn;
- struct expr *expr;
+handle_avail_expr (rtx insn, struct expr *expr)
{
rtx pat, insn_computes_expr, expr_set;
rtx to;
if (insn_computes_expr == NULL)
return 0;
expr_set = single_set (insn_computes_expr);
+ /* The set might be in a parallel with multiple sets; we could
+ probably handle that, but there's currently no easy way to find
+ the relevant sub-expression. */
if (!expr_set)
- abort ();
+ return 0;
found_setting = 0;
use_src = 0;
/* Perform classic GCSE. This is called by one_classic_gcse_pass after all
the dataflow analysis has been done.
- The result is non-zero if a change was made. */
+ The result is nonzero if a change was made. */
static int
-classic_gcse ()
+classic_gcse (void)
{
int changed;
rtx insn;
start of the block]. */
reset_opr_set_tables ();
- for (insn = bb->head;
- insn != NULL && insn != NEXT_INSN (bb->end);
+ for (insn = BB_HEAD (bb);
+ insn != NULL && insn != NEXT_INSN (BB_END (bb));
insn = NEXT_INSN (insn))
{
/* Is insn of form (set (pseudo-reg) ...)? */
if (want_to_gcse_p (src)
/* Is the expression recorded? */
- && ((expr = lookup_expr (src)) != NULL)
+ && ((expr = lookup_expr (src, &expr_hash_table)) != NULL)
/* Is the expression available [at the start of the
block]? */
&& TEST_BIT (ae_in[bb->index], expr->bitmap_index)
/* Top level routine to perform one classic GCSE pass.
- Return non-zero if a change was made. */
+ Return nonzero if a change was made. */
static int
-one_classic_gcse_pass (pass)
- int pass;
+one_classic_gcse_pass (int pass)
{
int changed = 0;
gcse_subst_count = 0;
gcse_create_count = 0;
- alloc_expr_hash_table (max_cuid);
+ alloc_hash_table (max_cuid, &expr_hash_table, 0);
alloc_rd_mem (last_basic_block, max_cuid);
- compute_expr_hash_table ();
+ compute_hash_table (&expr_hash_table);
if (gcse_file)
- dump_hash_table (gcse_file, "Expression", expr_hash_table,
- expr_hash_table_size, n_exprs);
+ dump_hash_table (gcse_file, "Expression", &expr_hash_table);
- if (n_exprs > 0)
+ if (expr_hash_table.n_elems > 0)
{
compute_kill_rd ();
compute_rd ();
- alloc_avail_expr_mem (last_basic_block, n_exprs);
- compute_ae_gen ();
- compute_ae_kill (ae_gen, ae_kill);
+ alloc_avail_expr_mem (last_basic_block, expr_hash_table.n_elems);
+ compute_ae_gen (&expr_hash_table);
+ compute_ae_kill (ae_gen, ae_kill, &expr_hash_table);
compute_available (ae_gen, ae_kill, ae_out, ae_in);
changed = classic_gcse ();
free_avail_expr_mem ();
}
free_rd_mem ();
- free_expr_hash_table ();
+ free_hash_table (&expr_hash_table);
if (gcse_file)
{
fprintf (gcse_file, "\n");
fprintf (gcse_file, "GCSE of %s, pass %d: %d bytes needed, %d substs,",
- current_function_name, pass, bytes_used, gcse_subst_count);
+ current_function_name (), pass, bytes_used, gcse_subst_count);
fprintf (gcse_file, "%d insns created\n", gcse_create_count);
}
basic blocks. N_SETS is the number of sets. */
static void
-alloc_cprop_mem (n_blocks, n_sets)
- int n_blocks, n_sets;
+alloc_cprop_mem (int n_blocks, int n_sets)
{
cprop_pavloc = sbitmap_vector_alloc (n_blocks, n_sets);
cprop_absaltered = sbitmap_vector_alloc (n_blocks, n_sets);
/* Free vars used by copy/const propagation. */
static void
-free_cprop_mem ()
+free_cprop_mem (void)
{
sbitmap_vector_free (cprop_pavloc);
sbitmap_vector_free (cprop_absaltered);
bit in BMAP. */
static void
-compute_transp (x, indx, bmap, set_p)
- rtx x;
- int indx;
- sbitmap *bmap;
- int set_p;
+compute_transp (rtx x, int indx, sbitmap *bmap, int set_p)
{
int i, j;
basic_block bb;
propagation. */
static void
-compute_cprop_data ()
+compute_cprop_data (void)
{
- compute_local_properties (cprop_absaltered, cprop_pavloc, NULL, 1);
+ compute_local_properties (cprop_absaltered, cprop_pavloc, NULL, &set_hash_table);
compute_available (cprop_pavloc, cprop_absaltered,
cprop_avout, cprop_avin);
}
This doesn't hurt anything but it will slow things down. */
static void
-find_used_regs (xptr, data)
- rtx *xptr;
- void *data ATTRIBUTE_UNUSED;
+find_used_regs (rtx *xptr, void *data ATTRIBUTE_UNUSED)
{
int i, j;
enum rtx_code code;
}
/* Try to replace all non-SET_DEST occurrences of FROM in INSN with TO.
- Returns non-zero is successful. */
+ Returns nonzero is successful. */
static int
-try_replace_reg (from, to, insn)
- rtx from, to, insn;
+try_replace_reg (rtx from, rtx to, rtx insn)
{
rtx note = find_reg_equal_equiv_note (insn);
rtx src = 0;
int success = 0;
rtx set = single_set (insn);
- success = validate_replace_src (from, to, insn);
+ validate_replace_src_group (from, to, insn);
+ if (num_changes_pending () && apply_change_group ())
+ success = 1;
- /* If above failed and this is a single set, try to simplify the source of
- the set given our substitution. We could perhaps try this for multiple
- SETs, but it probably won't buy us anything. */
- if (!success && set != 0)
+ /* Try to simplify SET_SRC if we have substituted a constant. */
+ if (success && set && CONSTANT_P (to))
{
- src = simplify_replace_rtx (SET_SRC (set), from, to);
+ src = simplify_rtx (SET_SRC (set));
- if (!rtx_equal_p (src, SET_SRC (set))
- && validate_change (insn, &SET_SRC (set), src, 0))
- success = 1;
+ if (src)
+ validate_change (insn, &SET_SRC (set), src, 0);
}
- /* If we've failed to do replacement, have a single SET, and don't already
- have a note, add a REG_EQUAL note to not lose information. */
- if (!success && note == 0 && set != 0)
- note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src));
-
/* If there is already a NOTE, update the expression in it with our
replacement. */
- else if (note != 0)
+ if (note != 0)
XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0), from, to);
+ if (!success && set && reg_mentioned_p (from, SET_SRC (set)))
+ {
+ /* If above failed and this is a single set, try to simplify the source of
+ the set given our substitution. We could perhaps try this for multiple
+ SETs, but it probably won't buy us anything. */
+ src = simplify_replace_rtx (SET_SRC (set), from, to);
+
+ if (!rtx_equal_p (src, SET_SRC (set))
+ && validate_change (insn, &SET_SRC (set), src, 0))
+ success = 1;
+
+ /* If we've failed to do replacement, have a single SET, don't already
+ have a note, and have no special SET, add a REG_EQUAL note to not
+ lose information. */
+ if (!success && note == 0 && set != 0
+ && GET_CODE (XEXP (set, 0)) != ZERO_EXTRACT
+ && GET_CODE (XEXP (set, 0)) != SIGN_EXTRACT)
+ note = set_unique_reg_note (insn, REG_EQUAL, copy_rtx (src));
+ }
+
/* REG_EQUAL may get simplified into register.
We don't allow that. Remove that note. This code ought
- not to hapen, because previous code ought to syntetize
+ not to happen, because previous code ought to synthesize
reg-reg move, but be on the safe side. */
if (note && REG_P (XEXP (note, 0)))
remove_note (insn, note);
NULL no such set is found. */
static struct expr *
-find_avail_set (regno, insn)
- int regno;
- rtx insn;
+find_avail_set (int regno, rtx insn)
{
/* SET1 contains the last set found that can be returned to the caller for
use in a substitution. */
while (1)
{
rtx src;
- struct expr *set = lookup_set (regno, NULL_RTX);
+ struct expr *set = lookup_set (regno, &set_hash_table);
/* Find a set that is available at the start of the block
which contains INSN. */
If the source operand changed, we may still use it for the next
iteration of this loop, but we may not use it for substitutions. */
- if (CONSTANT_P (src) || oprs_not_set_p (src, insn))
+ if (gcse_constant_p (src) || oprs_not_set_p (src, insn))
set1 = set;
/* If the source of the set is anything except a register, then
/* Subroutine of cprop_insn that tries to propagate constants into
JUMP_INSNS. JUMP must be a conditional jump. If SETCC is non-NULL
- it is the instruction that immediately preceeds JUMP, and must be a
+ it is the instruction that immediately precedes JUMP, and must be a
single SET of a register. FROM is what we will try to replace,
SRC is the constant we will try to substitute for it. Returns nonzero
if a change was made. */
static int
-cprop_jump (bb, setcc, jump, from, src)
- basic_block bb;
- rtx setcc;
- rtx jump;
- rtx from;
- rtx src;
-{
- rtx new, new_set;
+cprop_jump (basic_block bb, rtx setcc, rtx jump, rtx from, rtx src)
+{
+ rtx new, set_src, note_src;
rtx set = pc_set (jump);
+ rtx note = find_reg_equal_equiv_note (jump);
+
+ if (note)
+ {
+ note_src = XEXP (note, 0);
+ if (GET_CODE (note_src) == EXPR_LIST)
+ note_src = NULL_RTX;
+ }
+ else note_src = NULL_RTX;
+
+ /* Prefer REG_EQUAL notes except those containing EXPR_LISTs. */
+ set_src = note_src ? note_src : SET_SRC (set);
- /* First substitute in the INSN condition as the SET_SRC of the JUMP,
- then substitute that given values in this expanded JUMP. */
- if (setcc != NULL)
+ /* First substitute the SETCC condition into the JUMP instruction,
+ then substitute that given values into this expanded JUMP. */
+ if (setcc != NULL_RTX
+ && !modified_between_p (from, setcc, jump)
+ && !modified_between_p (src, setcc, jump))
{
+ rtx setcc_src;
rtx setcc_set = single_set (setcc);
- new_set = simplify_replace_rtx (SET_SRC (set),
- SET_DEST (setcc_set),
- SET_SRC (setcc_set));
+ rtx setcc_note = find_reg_equal_equiv_note (setcc);
+ setcc_src = (setcc_note && GET_CODE (XEXP (setcc_note, 0)) != EXPR_LIST)
+ ? XEXP (setcc_note, 0) : SET_SRC (setcc_set);
+ set_src = simplify_replace_rtx (set_src, SET_DEST (setcc_set),
+ setcc_src);
}
else
- new_set = set;
+ setcc = NULL_RTX;
- new = simplify_replace_rtx (new_set, from, src);
+ new = simplify_replace_rtx (set_src, from, src);
- /* If no simplification can be made, then try the next
- register. */
- if (rtx_equal_p (new, new_set))
+ /* If no simplification can be made, then try the next register. */
+ if (rtx_equal_p (new, SET_SRC (set)))
return 0;
/* If this is now a no-op delete it, otherwise this must be a valid insn. */
delete_insn (jump);
else
{
- if (! validate_change (jump, &SET_SRC (set), new, 0))
+ /* Ensure the value computed inside the jump insn to be equivalent
+ to one computed by setcc. */
+ if (setcc && modified_in_p (new, setcc))
return 0;
+ if (! validate_change (jump, &SET_SRC (set), new, 0))
+ {
+ /* When (some) constants are not valid in a comparison, and there
+ are two registers to be replaced by constants before the entire
+ comparison can be folded into a constant, we need to keep
+ intermediate information in REG_EQUAL notes. For targets with
+ separate compare insns, such notes are added by try_replace_reg.
+ When we have a combined compare-and-branch instruction, however,
+ we need to attach a note to the branch itself to make this
+ optimization work. */
+
+ if (!rtx_equal_p (new, note_src))
+ set_unique_reg_note (jump, REG_EQUAL, copy_rtx (new));
+ return 0;
+ }
+
+ /* Remove REG_EQUAL note after simplification. */
+ if (note_src)
+ remove_note (jump, note);
/* If this has turned into an unconditional jump,
then put a barrier after it so that the unreachable
return 1;
}
+static bool
+constprop_register (rtx insn, rtx from, rtx to, int alter_jumps)
+{
+ rtx sset;
+
+ /* Check for reg or cc0 setting instructions followed by
+ conditional branch instructions first. */
+ if (alter_jumps
+ && (sset = single_set (insn)) != NULL
+ && NEXT_INSN (insn)
+ && any_condjump_p (NEXT_INSN (insn)) && onlyjump_p (NEXT_INSN (insn)))
+ {
+ rtx dest = SET_DEST (sset);
+ if ((REG_P (dest) || CC0_P (dest))
+ && cprop_jump (BLOCK_FOR_INSN (insn), insn, NEXT_INSN (insn), from, to))
+ return 1;
+ }
+
+ /* Handle normal insns next. */
+ if (GET_CODE (insn) == INSN
+ && try_replace_reg (from, to, insn))
+ return 1;
+
+ /* Try to propagate a CONST_INT into a conditional jump.
+ We're pretty specific about what we will handle in this
+ code, we can extend this as necessary over time.
+
+ Right now the insn in question must look like
+ (set (pc) (if_then_else ...)) */
+ else if (alter_jumps && any_condjump_p (insn) && onlyjump_p (insn))
+ return cprop_jump (BLOCK_FOR_INSN (insn), NULL, insn, from, to);
+ return 0;
+}
+
/* Perform constant and copy propagation on INSN.
- The result is non-zero if a change was made. */
+ The result is nonzero if a change was made. */
static int
-cprop_insn (bb, insn, alter_jumps)
- basic_block bb;
- rtx insn;
- int alter_jumps;
+cprop_insn (rtx insn, int alter_jumps)
{
struct reg_use *reg_used;
int changed = 0;
src = SET_SRC (pat);
/* Constant propagation. */
- if (CONSTANT_P (src))
+ if (gcse_constant_p (src))
{
- rtx sset;
-
- /* Check for reg or cc0 setting instructions followed by
- conditional branch instructions first. */
- if (alter_jumps
- && (sset = single_set (insn)) != NULL
- && any_condjump_p (NEXT_INSN (insn))
- && onlyjump_p (NEXT_INSN (insn)))
- {
- rtx dest = SET_DEST (sset);
- if ((REG_P (dest) || CC0_P (dest))
- && cprop_jump (bb, insn, NEXT_INSN (insn),
- reg_used->reg_rtx, src))
- {
- changed = 1;
- break;
- }
- }
-
- /* Handle normal insns next. */
- if (GET_CODE (insn) == INSN
- && try_replace_reg (reg_used->reg_rtx, src, insn))
+ if (constprop_register (insn, reg_used->reg_rtx, src, alter_jumps))
{
changed = 1;
const_prop_count++;
if (gcse_file != NULL)
{
- fprintf (gcse_file, "CONST-PROP: Replacing reg %d in ",
- regno);
- fprintf (gcse_file, "insn %d with constant ",
- INSN_UID (insn));
+ fprintf (gcse_file, "GLOBAL CONST-PROP: Replacing reg %d in ", regno);
+ fprintf (gcse_file, "insn %d with constant ", INSN_UID (insn));
print_rtl (gcse_file, src);
fprintf (gcse_file, "\n");
}
-
- /* The original insn setting reg_used may or may not now be
- deletable. We leave the deletion to flow. */
+ if (INSN_DELETED_P (insn))
+ return 1;
}
-
- /* Try to propagate a CONST_INT into a conditional jump.
- We're pretty specific about what we will handle in this
- code, we can extend this as necessary over time.
-
- Right now the insn in question must look like
- (set (pc) (if_then_else ...)) */
- else if (alter_jumps
- && any_condjump_p (insn)
- && onlyjump_p (insn))
- changed |= cprop_jump (bb, NULL, insn, reg_used->reg_rtx, src);
-
}
else if (GET_CODE (src) == REG
&& REGNO (src) >= FIRST_PSEUDO_REGISTER
copy_prop_count++;
if (gcse_file != NULL)
{
- fprintf (gcse_file, "COPY-PROP: Replacing reg %d in insn %d",
+ fprintf (gcse_file, "GLOBAL COPY-PROP: Replacing reg %d in insn %d",
regno, INSN_UID (insn));
fprintf (gcse_file, " with reg %d\n", REGNO (src));
}
return changed;
}
-/* Forward propagate copies. This includes copies and constants. Return
- non-zero if a change was made. */
+/* Like find_used_regs, but avoid recording uses that appear in
+ input-output contexts such as zero_extract or pre_dec. This
+ restricts the cases we consider to those for which local cprop
+ can legitimately make replacements. */
-static int
-cprop (alter_jumps)
- int alter_jumps;
+static void
+local_cprop_find_used_regs (rtx *xptr, void *data)
{
- int changed;
- basic_block bb;
- rtx insn;
+ rtx x = *xptr;
- /* Note we start at block 1. */
- if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR)
- {
- if (gcse_file != NULL)
- fprintf (gcse_file, "\n");
- return 0;
- }
+ if (x == 0)
+ return;
- changed = 0;
- FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb)
+ switch (GET_CODE (x))
{
- /* Reset tables used to keep track of what's still valid [since the
- start of the block]. */
- reset_opr_set_tables ();
+ case ZERO_EXTRACT:
+ case SIGN_EXTRACT:
+ case STRICT_LOW_PART:
+ return;
- for (insn = bb->head;
- insn != NULL && insn != NEXT_INSN (bb->end);
- insn = NEXT_INSN (insn))
- if (INSN_P (insn))
- {
- changed |= cprop_insn (bb, insn, alter_jumps);
+ case PRE_DEC:
+ case PRE_INC:
+ case POST_DEC:
+ case POST_INC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
+ /* Can only legitimately appear this early in the context of
+ stack pushes for function arguments, but handle all of the
+ codes nonetheless. */
+ return;
- /* Keep track of everything modified by this insn. */
- /* ??? Need to be careful w.r.t. mods done to INSN. Don't
- call mark_oprs_set if we turned the insn into a NOTE. */
- if (GET_CODE (insn) != NOTE)
- mark_oprs_set (insn);
- }
- }
+ case SUBREG:
+ /* Setting a subreg of a register larger than word_mode leaves
+ the non-written words unchanged. */
+ if (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x))) > BITS_PER_WORD)
+ return;
+ break;
- if (gcse_file != NULL)
- fprintf (gcse_file, "\n");
+ default:
+ break;
+ }
- return changed;
+ find_used_regs (xptr, data);
}
-/* Perform one copy/constant propagation pass.
- F is the first insn in the function.
- PASS is the pass count. */
+/* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall;
+ their REG_EQUAL notes need updating. */
-static int
-one_cprop_pass (pass, alter_jumps)
- int pass;
- int alter_jumps;
+static bool
+do_local_cprop (rtx x, rtx insn, int alter_jumps, rtx *libcall_sp)
{
- int changed = 0;
-
- const_prop_count = 0;
- copy_prop_count = 0;
-
- alloc_set_hash_table (max_cuid);
- compute_set_hash_table ();
- if (gcse_file)
- dump_hash_table (gcse_file, "SET", set_hash_table, set_hash_table_size,
- n_sets);
- if (n_sets > 0)
- {
- alloc_cprop_mem (last_basic_block, n_sets);
- compute_cprop_data ();
- changed = cprop (alter_jumps);
- if (alter_jumps)
- changed |= bypass_conditional_jumps ();
- free_cprop_mem ();
- }
-
- free_set_hash_table ();
+ rtx newreg = NULL, newcnst = NULL;
- if (gcse_file)
+ /* Rule out USE instructions and ASM statements as we don't want to
+ change the hard registers mentioned. */
+ if (GET_CODE (x) == REG
+ && (REGNO (x) >= FIRST_PSEUDO_REGISTER
+ || (GET_CODE (PATTERN (insn)) != USE
+ && asm_noperands (PATTERN (insn)) < 0)))
{
- fprintf (gcse_file, "CPROP of %s, pass %d: %d bytes needed, ",
- current_function_name, pass, bytes_used);
- fprintf (gcse_file, "%d const props, %d copy props\n\n",
- const_prop_count, copy_prop_count);
- }
-
- return changed;
-}
-\f
-/* Bypass conditional jumps. */
+ cselib_val *val = cselib_lookup (x, GET_MODE (x), 0);
+ struct elt_loc_list *l;
-/* Find a set of REGNO to a constant that is available at the end of basic
- block BB. Returns NULL if no such set is found. Based heavily upon
- find_avail_set. */
+ if (!val)
+ return false;
+ for (l = val->locs; l; l = l->next)
+ {
+ rtx this_rtx = l->loc;
+ rtx note;
-static struct expr *
-find_bypass_set (regno, bb)
- int regno;
- int bb;
-{
- struct expr *result = 0;
+ if (l->in_libcall)
+ continue;
+
+ if (gcse_constant_p (this_rtx))
+ newcnst = this_rtx;
+ if (REG_P (this_rtx) && REGNO (this_rtx) >= FIRST_PSEUDO_REGISTER
+ /* Don't copy propagate if it has attached REG_EQUIV note.
+ At this point this only function parameters should have
+ REG_EQUIV notes and if the argument slot is used somewhere
+ explicitly, it means address of parameter has been taken,
+ so we should not extend the lifetime of the pseudo. */
+ && (!(note = find_reg_note (l->setting_insn, REG_EQUIV, NULL_RTX))
+ || GET_CODE (XEXP (note, 0)) != MEM))
+ newreg = this_rtx;
+ }
+ if (newcnst && constprop_register (insn, x, newcnst, alter_jumps))
+ {
+ /* If we find a case where we can't fix the retval REG_EQUAL notes
+ match the new register, we either have to abandon this replacement
+ or fix delete_trivially_dead_insns to preserve the setting insn,
+ or make it delete the REG_EUAQL note, and fix up all passes that
+ require the REG_EQUAL note there. */
+ if (!adjust_libcall_notes (x, newcnst, insn, libcall_sp))
+ abort ();
+ if (gcse_file != NULL)
+ {
+ fprintf (gcse_file, "LOCAL CONST-PROP: Replacing reg %d in ",
+ REGNO (x));
+ fprintf (gcse_file, "insn %d with constant ",
+ INSN_UID (insn));
+ print_rtl (gcse_file, newcnst);
+ fprintf (gcse_file, "\n");
+ }
+ const_prop_count++;
+ return true;
+ }
+ else if (newreg && newreg != x && try_replace_reg (x, newreg, insn))
+ {
+ adjust_libcall_notes (x, newreg, insn, libcall_sp);
+ if (gcse_file != NULL)
+ {
+ fprintf (gcse_file,
+ "LOCAL COPY-PROP: Replacing reg %d in insn %d",
+ REGNO (x), INSN_UID (insn));
+ fprintf (gcse_file, " with reg %d\n", REGNO (newreg));
+ }
+ copy_prop_count++;
+ return true;
+ }
+ }
+ return false;
+}
+
+/* LIBCALL_SP is a zero-terminated array of insns at the end of a libcall;
+ their REG_EQUAL notes need updating to reflect that OLDREG has been
+ replaced with NEWVAL in INSN. Return true if all substitutions could
+ be made. */
+static bool
+adjust_libcall_notes (rtx oldreg, rtx newval, rtx insn, rtx *libcall_sp)
+{
+ rtx end;
+
+ while ((end = *libcall_sp++))
+ {
+ rtx note = find_reg_equal_equiv_note (end);
+
+ if (! note)
+ continue;
+
+ if (REG_P (newval))
+ {
+ if (reg_set_between_p (newval, PREV_INSN (insn), end))
+ {
+ do
+ {
+ note = find_reg_equal_equiv_note (end);
+ if (! note)
+ continue;
+ if (reg_mentioned_p (newval, XEXP (note, 0)))
+ return false;
+ }
+ while ((end = *libcall_sp++));
+ return true;
+ }
+ }
+ XEXP (note, 0) = replace_rtx (XEXP (note, 0), oldreg, newval);
+ insn = end;
+ }
+ return true;
+}
+
+#define MAX_NESTED_LIBCALLS 9
+
+static void
+local_cprop_pass (int alter_jumps)
+{
+ rtx insn;
+ struct reg_use *reg_used;
+ rtx libcall_stack[MAX_NESTED_LIBCALLS + 1], *libcall_sp;
+ bool changed = false;
+
+ cselib_init ();
+ libcall_sp = &libcall_stack[MAX_NESTED_LIBCALLS];
+ *libcall_sp = 0;
+ for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
+ {
+ if (INSN_P (insn))
+ {
+ rtx note = find_reg_note (insn, REG_LIBCALL, NULL_RTX);
+
+ if (note)
+ {
+ if (libcall_sp == libcall_stack)
+ abort ();
+ *--libcall_sp = XEXP (note, 0);
+ }
+ note = find_reg_note (insn, REG_RETVAL, NULL_RTX);
+ if (note)
+ libcall_sp++;
+ note = find_reg_equal_equiv_note (insn);
+ do
+ {
+ reg_use_count = 0;
+ note_uses (&PATTERN (insn), local_cprop_find_used_regs, NULL);
+ if (note)
+ local_cprop_find_used_regs (&XEXP (note, 0), NULL);
+
+ for (reg_used = ®_use_table[0]; reg_use_count > 0;
+ reg_used++, reg_use_count--)
+ if (do_local_cprop (reg_used->reg_rtx, insn, alter_jumps,
+ libcall_sp))
+ {
+ changed = true;
+ break;
+ }
+ if (INSN_DELETED_P (insn))
+ break;
+ }
+ while (reg_use_count);
+ }
+ cselib_process_insn (insn);
+ }
+ cselib_finish ();
+ /* Global analysis may get into infinite loops for unreachable blocks. */
+ if (changed && alter_jumps)
+ {
+ delete_unreachable_blocks ();
+ free_reg_set_mem ();
+ alloc_reg_set_mem (max_reg_num ());
+ compute_sets (get_insns ());
+ }
+}
+
+/* Forward propagate copies. This includes copies and constants. Return
+ nonzero if a change was made. */
+
+static int
+cprop (int alter_jumps)
+{
+ int changed;
+ basic_block bb;
+ rtx insn;
+
+ /* Note we start at block 1. */
+ if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR)
+ {
+ if (gcse_file != NULL)
+ fprintf (gcse_file, "\n");
+ return 0;
+ }
+
+ changed = 0;
+ FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb, EXIT_BLOCK_PTR, next_bb)
+ {
+ /* Reset tables used to keep track of what's still valid [since the
+ start of the block]. */
+ reset_opr_set_tables ();
+
+ for (insn = BB_HEAD (bb);
+ insn != NULL && insn != NEXT_INSN (BB_END (bb));
+ insn = NEXT_INSN (insn))
+ if (INSN_P (insn))
+ {
+ changed |= cprop_insn (insn, alter_jumps);
+
+ /* Keep track of everything modified by this insn. */
+ /* ??? Need to be careful w.r.t. mods done to INSN. Don't
+ call mark_oprs_set if we turned the insn into a NOTE. */
+ if (GET_CODE (insn) != NOTE)
+ mark_oprs_set (insn);
+ }
+ }
+
+ if (gcse_file != NULL)
+ fprintf (gcse_file, "\n");
+
+ return changed;
+}
+
+/* Similar to get_condition, only the resulting condition must be
+ valid at JUMP, instead of at EARLIEST.
+
+ This differs from noce_get_condition in ifcvt.c in that we prefer not to
+ settle for the condition variable in the jump instruction being integral.
+ We prefer to be able to record the value of a user variable, rather than
+ the value of a temporary used in a condition. This could be solved by
+ recording the value of *every* register scaned by canonicalize_condition,
+ but this would require some code reorganization. */
+
+rtx
+fis_get_condition (rtx jump)
+{
+ rtx cond, set, tmp, insn, earliest;
+ bool reverse;
+
+ if (! any_condjump_p (jump))
+ return NULL_RTX;
+
+ set = pc_set (jump);
+ cond = XEXP (SET_SRC (set), 0);
+
+ /* If this branches to JUMP_LABEL when the condition is false,
+ reverse the condition. */
+ reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
+ && XEXP (XEXP (SET_SRC (set), 2), 0) == JUMP_LABEL (jump));
+
+ /* Use canonicalize_condition to do the dirty work of manipulating
+ MODE_CC values and COMPARE rtx codes. */
+ tmp = canonicalize_condition (jump, cond, reverse, &earliest, NULL_RTX,
+ false);
+ if (!tmp)
+ return NULL_RTX;
+
+ /* Verify that the given condition is valid at JUMP by virtue of not
+ having been modified since EARLIEST. */
+ for (insn = earliest; insn != jump; insn = NEXT_INSN (insn))
+ if (INSN_P (insn) && modified_in_p (tmp, insn))
+ break;
+ if (insn == jump)
+ return tmp;
+
+ /* The condition was modified. See if we can get a partial result
+ that doesn't follow all the reversals. Perhaps combine can fold
+ them together later. */
+ tmp = XEXP (tmp, 0);
+ if (!REG_P (tmp) || GET_MODE_CLASS (GET_MODE (tmp)) != MODE_INT)
+ return NULL_RTX;
+ tmp = canonicalize_condition (jump, cond, reverse, &earliest, tmp,
+ false);
+ if (!tmp)
+ return NULL_RTX;
+
+ /* For sanity's sake, re-validate the new result. */
+ for (insn = earliest; insn != jump; insn = NEXT_INSN (insn))
+ if (INSN_P (insn) && modified_in_p (tmp, insn))
+ return NULL_RTX;
+
+ return tmp;
+}
+
+/* Check the comparison COND to see if we can safely form an implicit set from
+ it. COND is either an EQ or NE comparison. */
+
+static bool
+implicit_set_cond_p (rtx cond)
+{
+ enum machine_mode mode = GET_MODE (XEXP (cond, 0));
+ rtx cst = XEXP (cond, 1);
+
+ /* We can't perform this optimization if either operand might be or might
+ contain a signed zero. */
+ if (HONOR_SIGNED_ZEROS (mode))
+ {
+ /* It is sufficient to check if CST is or contains a zero. We must
+ handle float, complex, and vector. If any subpart is a zero, then
+ the optimization can't be performed. */
+ /* ??? The complex and vector checks are not implemented yet. We just
+ always return zero for them. */
+ if (GET_CODE (cst) == CONST_DOUBLE)
+ {
+ REAL_VALUE_TYPE d;
+ REAL_VALUE_FROM_CONST_DOUBLE (d, cst);
+ if (REAL_VALUES_EQUAL (d, dconst0))
+ return 0;
+ }
+ else
+ return 0;
+ }
+
+ return gcse_constant_p (cst);
+}
+
+/* Find the implicit sets of a function. An "implicit set" is a constraint
+ on the value of a variable, implied by a conditional jump. For example,
+ following "if (x == 2)", the then branch may be optimized as though the
+ conditional performed an "explicit set", in this example, "x = 2". This
+ function records the set patterns that are implicit at the start of each
+ basic block. */
+
+static void
+find_implicit_sets (void)
+{
+ basic_block bb, dest;
+ unsigned int count;
+ rtx cond, new;
+
+ count = 0;
+ FOR_EACH_BB (bb)
+ /* Check for more than one successor. */
+ if (bb->succ && bb->succ->succ_next)
+ {
+ cond = fis_get_condition (BB_END (bb));
+
+ if (cond
+ && (GET_CODE (cond) == EQ || GET_CODE (cond) == NE)
+ && GET_CODE (XEXP (cond, 0)) == REG
+ && REGNO (XEXP (cond, 0)) >= FIRST_PSEUDO_REGISTER
+ && implicit_set_cond_p (cond))
+ {
+ dest = GET_CODE (cond) == EQ ? BRANCH_EDGE (bb)->dest
+ : FALLTHRU_EDGE (bb)->dest;
+
+ if (dest && ! dest->pred->pred_next
+ && dest != EXIT_BLOCK_PTR)
+ {
+ new = gen_rtx_SET (VOIDmode, XEXP (cond, 0),
+ XEXP (cond, 1));
+ implicit_sets[dest->index] = new;
+ if (gcse_file)
+ {
+ fprintf(gcse_file, "Implicit set of reg %d in ",
+ REGNO (XEXP (cond, 0)));
+ fprintf(gcse_file, "basic block %d\n", dest->index);
+ }
+ count++;
+ }
+ }
+ }
+
+ if (gcse_file)
+ fprintf (gcse_file, "Found %d implicit sets\n", count);
+}
+
+/* Perform one copy/constant propagation pass.
+ PASS is the pass count. If CPROP_JUMPS is true, perform constant
+ propagation into conditional jumps. If BYPASS_JUMPS is true,
+ perform conditional jump bypassing optimizations. */
+
+static int
+one_cprop_pass (int pass, int cprop_jumps, int bypass_jumps)
+{
+ int changed = 0;
+
+ const_prop_count = 0;
+ copy_prop_count = 0;
+
+ local_cprop_pass (cprop_jumps);
+
+ /* Determine implicit sets. */
+ implicit_sets = xcalloc (last_basic_block, sizeof (rtx));
+ find_implicit_sets ();
+
+ alloc_hash_table (max_cuid, &set_hash_table, 1);
+ compute_hash_table (&set_hash_table);
+
+ /* Free implicit_sets before peak usage. */
+ free (implicit_sets);
+ implicit_sets = NULL;
+
+ if (gcse_file)
+ dump_hash_table (gcse_file, "SET", &set_hash_table);
+ if (set_hash_table.n_elems > 0)
+ {
+ alloc_cprop_mem (last_basic_block, set_hash_table.n_elems);
+ compute_cprop_data ();
+ changed = cprop (cprop_jumps);
+ if (bypass_jumps)
+ changed |= bypass_conditional_jumps ();
+ free_cprop_mem ();
+ }
+
+ free_hash_table (&set_hash_table);
+
+ if (gcse_file)
+ {
+ fprintf (gcse_file, "CPROP of %s, pass %d: %d bytes needed, ",
+ current_function_name (), pass, bytes_used);
+ fprintf (gcse_file, "%d const props, %d copy props\n\n",
+ const_prop_count, copy_prop_count);
+ }
+ /* Global analysis may get into infinite loops for unreachable blocks. */
+ if (changed && cprop_jumps)
+ delete_unreachable_blocks ();
+
+ return changed;
+}
+\f
+/* Bypass conditional jumps. */
+
+/* The value of last_basic_block at the beginning of the jump_bypass
+ pass. The use of redirect_edge_and_branch_force may introduce new
+ basic blocks, but the data flow analysis is only valid for basic
+ block indices less than bypass_last_basic_block. */
+
+static int bypass_last_basic_block;
+
+/* Find a set of REGNO to a constant that is available at the end of basic
+ block BB. Returns NULL if no such set is found. Based heavily upon
+ find_avail_set. */
+
+static struct expr *
+find_bypass_set (int regno, int bb)
+{
+ struct expr *result = 0;
for (;;)
{
rtx src;
- struct expr *set = lookup_set (regno, NULL_RTX);
+ struct expr *set = lookup_set (regno, &set_hash_table);
while (set)
{
abort ();
src = SET_SRC (set->expr);
- if (CONSTANT_P (src))
+ if (gcse_constant_p (src))
result = set;
if (GET_CODE (src) != REG)
}
+/* Subroutine of bypass_block that checks whether a pseudo is killed by
+ any of the instructions inserted on an edge. Jump bypassing places
+ condition code setters on CFG edges using insert_insn_on_edge. This
+ function is required to check that our data flow analysis is still
+ valid prior to commit_edge_insertions. */
+
+static bool
+reg_killed_on_edge (rtx reg, edge e)
+{
+ rtx insn;
+
+ for (insn = e->insns; insn; insn = NEXT_INSN (insn))
+ if (INSN_P (insn) && reg_set_p (reg, insn))
+ return true;
+
+ return false;
+}
+
/* Subroutine of bypass_conditional_jumps that attempts to bypass the given
basic block BB which has more than one predecessor. If not NULL, SETCC
is the first instruction of BB, which is immediately followed by JUMP_INSN
JUMP. Otherwise, SETCC is NULL, and JUMP is the first insn of BB.
- Returns nonzero if a change was made. */
+ Returns nonzero if a change was made.
+
+ During the jump bypassing pass, we may place copies of SETCC instructions
+ on CFG edges. The following routine must be careful to pay attention to
+ these inserted insns when performing its transformations. */
static int
-bypass_block (bb, setcc, jump)
- basic_block bb;
- rtx setcc, jump;
+bypass_block (basic_block bb, rtx setcc, rtx jump)
{
rtx insn, note;
- edge e, enext;
+ edge e, enext, edest;
int i, change;
+ int may_be_loop_header;
insn = (setcc != NULL) ? setcc : jump;
if (note)
find_used_regs (&XEXP (note, 0), NULL);
+ may_be_loop_header = false;
+ for (e = bb->pred; e; e = e->pred_next)
+ if (e->flags & EDGE_DFS_BACK)
+ {
+ may_be_loop_header = true;
+ break;
+ }
+
change = 0;
for (e = bb->pred; e; e = enext)
{
enext = e->pred_next;
+ if (e->flags & EDGE_COMPLEX)
+ continue;
+
+ /* We can't redirect edges from new basic blocks. */
+ if (e->src->index >= bypass_last_basic_block)
+ continue;
+
+ /* The irreducible loops created by redirecting of edges entering the
+ loop from outside would decrease effectiveness of some of the following
+ optimizations, so prevent this. */
+ if (may_be_loop_header
+ && !(e->flags & EDGE_DFS_BACK))
+ continue;
+
for (i = 0; i < reg_use_count; i++)
{
struct reg_use *reg_used = ®_use_table[i];
if (! set)
continue;
+ /* Check the data flow is valid after edge insertions. */
+ if (e->insns && reg_killed_on_edge (reg_used->reg_rtx, e))
+ continue;
+
src = SET_SRC (pc_set (jump));
if (setcc != NULL)
new = simplify_replace_rtx (src, reg_used->reg_rtx,
SET_SRC (set->expr));
+ /* Jump bypassing may have already placed instructions on
+ edges of the CFG. We can't bypass an outgoing edge that
+ has instructions associated with it, as these insns won't
+ get executed if the incoming edge is redirected. */
+
if (new == pc_rtx)
- dest = FALLTHRU_EDGE (bb)->dest;
+ {
+ edest = FALLTHRU_EDGE (bb);
+ dest = edest->insns ? NULL : edest->dest;
+ }
else if (GET_CODE (new) == LABEL_REF)
- dest = BRANCH_EDGE (bb)->dest;
+ {
+ dest = BLOCK_FOR_INSN (XEXP (new, 0));
+ /* Don't bypass edges containing instructions. */
+ for (edest = bb->succ; edest; edest = edest->succ_next)
+ if (edest->dest == dest && edest->insns)
+ {
+ dest = NULL;
+ break;
+ }
+ }
else
dest = NULL;
- /* Once basic block indices are stable, we should be able
- to use redirect_edge_and_branch_force instead. */
- old_dest = e->dest;
- if (dest != NULL && dest != old_dest
- && redirect_edge_and_branch (e, dest))
+ /* Avoid unification of the edge with other edges from original
+ branch. We would end up emitting the instruction on "both"
+ edges. */
+
+ if (dest && setcc && !CC0_P (SET_DEST (PATTERN (setcc))))
{
+ edge e2;
+ for (e2 = e->src->succ; e2; e2 = e2->succ_next)
+ if (e2->dest == dest)
+ {
+ dest = NULL;
+ break;
+ }
+ }
+
+ old_dest = e->dest;
+ if (dest != NULL
+ && dest != old_dest
+ && dest != EXIT_BLOCK_PTR)
+ {
+ redirect_edge_and_branch_force (e, dest);
+
/* Copy the register setter to the redirected edge.
Don't copy CC0 setters, as CC0 is dead after jump. */
if (setcc)
/* Find basic blocks with more than one predecessor that only contain a
single conditional jump. If the result of the comparison is known at
compile-time from any incoming edge, redirect that edge to the
- appropriate target. Returns nonzero if a change was made. */
+ appropriate target. Returns nonzero if a change was made.
+
+ This function is now mis-named, because we also handle indirect jumps. */
static int
-bypass_conditional_jumps ()
+bypass_conditional_jumps (void)
{
basic_block bb;
int changed;
if (ENTRY_BLOCK_PTR->next_bb == EXIT_BLOCK_PTR)
return 0;
+ bypass_last_basic_block = last_basic_block;
+ mark_dfs_back_edges ();
+
changed = 0;
FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR->next_bb->next_bb,
EXIT_BLOCK_PTR, next_bb)
if (bb->pred && bb->pred->pred_next)
{
setcc = NULL_RTX;
- for (insn = bb->head;
- insn != NULL && insn != NEXT_INSN (bb->end);
+ for (insn = BB_HEAD (bb);
+ insn != NULL && insn != NEXT_INSN (BB_END (bb));
insn = NEXT_INSN (insn))
if (GET_CODE (insn) == INSN)
{
}
else if (GET_CODE (insn) == JUMP_INSN)
{
- if (any_condjump_p (insn) && onlyjump_p (insn))
+ if ((any_condjump_p (insn) || computed_jump_p (insn))
+ && onlyjump_p (insn))
changed |= bypass_block (bb, setcc, insn);
break;
}
}
/* If we bypassed any register setting insns, we inserted a
- copy on the redirected edge. These need to be commited. */
+ copy on the redirected edge. These need to be committed. */
if (changed)
commit_edge_insertions();
/* Allocate vars used for PRE analysis. */
static void
-alloc_pre_mem (n_blocks, n_exprs)
- int n_blocks, n_exprs;
+alloc_pre_mem (int n_blocks, int n_exprs)
{
transp = sbitmap_vector_alloc (n_blocks, n_exprs);
comp = sbitmap_vector_alloc (n_blocks, n_exprs);
/* Free vars used for PRE analysis. */
static void
-free_pre_mem ()
+free_pre_mem (void)
{
sbitmap_vector_free (transp);
sbitmap_vector_free (comp);
/* Top level routine to do the dataflow analysis needed by PRE. */
static void
-compute_pre_data ()
+compute_pre_data (void)
{
sbitmap trapping_expr;
basic_block bb;
unsigned int ui;
- compute_local_properties (transp, comp, antloc, 0);
+ compute_local_properties (transp, comp, antloc, &expr_hash_table);
sbitmap_vector_zero (ae_kill, last_basic_block);
/* Collect expressions which might trap. */
- trapping_expr = sbitmap_alloc (n_exprs);
+ trapping_expr = sbitmap_alloc (expr_hash_table.n_elems);
sbitmap_zero (trapping_expr);
- for (ui = 0; ui < expr_hash_table_size; ui++)
+ for (ui = 0; ui < expr_hash_table.size; ui++)
{
struct expr *e;
- for (e = expr_hash_table[ui]; e != NULL; e = e->next_same_hash)
+ for (e = expr_hash_table.table[ui]; e != NULL; e = e->next_same_hash)
if (may_trap_p (e->expr))
SET_BIT (trapping_expr, e->bitmap_index);
}
sbitmap_not (ae_kill[bb->index], ae_kill[bb->index]);
}
- edge_list = pre_edge_lcm (gcse_file, n_exprs, transp, comp, antloc,
+ edge_list = pre_edge_lcm (gcse_file, expr_hash_table.n_elems, transp, comp, antloc,
ae_kill, &pre_insert_map, &pre_delete_map);
sbitmap_vector_free (antloc);
antloc = NULL;
\f
/* PRE utilities */
-/* Return non-zero if an occurrence of expression EXPR in OCCR_BB would reach
+/* Return nonzero if an occurrence of expression EXPR in OCCR_BB would reach
block BB.
VISITED is a pointer to a working buffer for tracking which BB's have
the closest such expression. */
static int
-pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited)
- basic_block occr_bb;
- struct expr *expr;
- basic_block bb;
- char *visited;
+pre_expr_reaches_here_p_work (basic_block occr_bb, struct expr *expr, basic_block bb, char *visited)
{
edge pred;
memory allocated for that function is returned. */
static int
-pre_expr_reaches_here_p (occr_bb, expr, bb)
- basic_block occr_bb;
- struct expr *expr;
- basic_block bb;
+pre_expr_reaches_here_p (basic_block occr_bb, struct expr *expr, basic_block bb)
{
int rval;
- char *visited = (char *) xcalloc (last_basic_block, 1);
+ char *visited = xcalloc (last_basic_block, 1);
rval = pre_expr_reaches_here_p_work (occr_bb, expr, bb, visited);
the value of BB. */
static rtx
-process_insert_insn (expr)
- struct expr *expr;
+process_insert_insn (struct expr *expr)
{
rtx reg = expr->reaching_reg;
rtx exp = copy_rtx (expr->expr);
no sense for code hoisting. */
static void
-insert_insn_end_bb (expr, bb, pre)
- struct expr *expr;
- basic_block bb;
- int pre;
+insert_insn_end_bb (struct expr *expr, basic_block bb, int pre)
{
- rtx insn = bb->end;
+ rtx insn = BB_END (bb);
rtx new_insn;
rtx reg = expr->reaching_reg;
int regno = REGNO (reg);
pat_end = NEXT_INSN (pat_end);
/* If the last insn is a jump, insert EXPR in front [taking care to
- handle cc0, etc. properly]. Similary we need to care trapping
+ handle cc0, etc. properly]. Similarly we need to care trapping
instructions in presence of non-call exceptions. */
if (GET_CODE (insn) == JUMP_INSN
/* Keeping in mind SMALL_REGISTER_CLASSES and parameters in registers,
we search backward and place the instructions before the first
parameter is loaded. Do this for everyone for consistency and a
- presumtion that we'll get better code elsewhere as well.
+ presumption that we'll get better code elsewhere as well.
It should always be the case that we can put these instructions
anywhere in the basic block with performing PRE optimizations.
/* Since different machines initialize their parameter registers
in different orders, assume nothing. Collect the set of all
parameter registers. */
- insn = find_first_parameter_load (insn, bb->head);
+ insn = find_first_parameter_load (insn, BB_HEAD (bb));
/* If we found all the parameter loads, then we want to insert
before the first parameter load.
the expressions fully redundant. */
static int
-pre_edge_insert (edge_list, index_map)
- struct edge_list *edge_list;
- struct expr **index_map;
+pre_edge_insert (struct edge_list *edge_list, struct expr **index_map)
{
int e, i, j, num_edges, set_size, did_insert = 0;
sbitmap *inserted;
set_size = pre_insert_map[0]->size;
num_edges = NUM_EDGES (edge_list);
- inserted = sbitmap_vector_alloc (num_edges, n_exprs);
+ inserted = sbitmap_vector_alloc (num_edges, expr_hash_table.n_elems);
sbitmap_vector_zero (inserted, num_edges);
for (e = 0; e < num_edges; e++)
{
SBITMAP_ELT_TYPE insert = pre_insert_map[e]->elms[i];
- for (j = indx; insert && j < n_exprs; j++, insert >>= 1)
+ for (j = indx; insert && j < (int) expr_hash_table.n_elems; j++, insert >>= 1)
if ((insert & 1) != 0 && index_map[j]->reaching_reg != NULL_RTX)
{
struct expr *expr = index_map[j];
return did_insert;
}
-/* Copy the result of INSN to REG. INDX is the expression number. */
+/* Copy the result of EXPR->EXPR generated by INSN to EXPR->REACHING_REG.
+ Given "old_reg <- expr" (INSN), instead of adding after it
+ reaching_reg <- old_reg
+ it's better to do the following:
+ reaching_reg <- expr
+ old_reg <- reaching_reg
+ because this way copy propagation can discover additional PRE
+ opportunities. But if this fails, we try the old way.
+ When "expr" is a store, i.e.
+ given "MEM <- old_reg", instead of adding after it
+ reaching_reg <- old_reg
+ it's better to add it before as follows:
+ reaching_reg <- old_reg
+ MEM <- reaching_reg. */
static void
-pre_insert_copy_insn (expr, insn)
- struct expr *expr;
- rtx insn;
+pre_insert_copy_insn (struct expr *expr, rtx insn)
{
rtx reg = expr->reaching_reg;
int regno = REGNO (reg);
int indx = expr->bitmap_index;
- rtx set = single_set (insn);
- rtx new_insn;
+ rtx pat = PATTERN (insn);
+ rtx set, new_insn;
+ rtx old_reg;
+ int i;
- if (!set)
+ /* This block matches the logic in hash_scan_insn. */
+ if (GET_CODE (pat) == SET)
+ set = pat;
+ else if (GET_CODE (pat) == PARALLEL)
+ {
+ /* Search through the parallel looking for the set whose
+ source was the expression that we're interested in. */
+ set = NULL_RTX;
+ for (i = 0; i < XVECLEN (pat, 0); i++)
+ {
+ rtx x = XVECEXP (pat, 0, i);
+ if (GET_CODE (x) == SET
+ && expr_equiv_p (SET_SRC (x), expr->expr))
+ {
+ set = x;
+ break;
+ }
+ }
+ }
+ else
abort ();
- new_insn = emit_insn_after (gen_move_insn (reg, SET_DEST (set)), insn);
+ if (GET_CODE (SET_DEST (set)) == REG)
+ {
+ old_reg = SET_DEST (set);
+ /* Check if we can modify the set destination in the original insn. */
+ if (validate_change (insn, &SET_DEST (set), reg, 0))
+ {
+ new_insn = gen_move_insn (old_reg, reg);
+ new_insn = emit_insn_after (new_insn, insn);
+
+ /* Keep register set table up to date. */
+ replace_one_set (REGNO (old_reg), insn, new_insn);
+ record_one_set (regno, insn);
+ }
+ else
+ {
+ new_insn = gen_move_insn (reg, old_reg);
+ new_insn = emit_insn_after (new_insn, insn);
+
+ /* Keep register set table up to date. */
+ record_one_set (regno, new_insn);
+ }
+ }
+ else /* This is possible only in case of a store to memory. */
+ {
+ old_reg = SET_SRC (set);
+ new_insn = gen_move_insn (reg, old_reg);
+
+ /* Check if we can modify the set source in the original insn. */
+ if (validate_change (insn, &SET_SRC (set), reg, 0))
+ new_insn = emit_insn_before (new_insn, insn);
+ else
+ new_insn = emit_insn_after (new_insn, insn);
- /* Keep register set table up to date. */
- record_one_set (regno, new_insn);
+ /* Keep register set table up to date. */
+ record_one_set (regno, new_insn);
+ }
gcse_create_count++;
"PRE: bb %d, insn %d, copy expression %d in insn %d to reg %d\n",
BLOCK_NUM (insn), INSN_UID (new_insn), indx,
INSN_UID (insn), regno);
- update_ld_motion_stores (expr);
}
/* Copy available expressions that reach the redundant expression
to `reaching_reg'. */
static void
-pre_insert_copies ()
+pre_insert_copies (void)
{
- unsigned int i;
+ unsigned int i, added_copy;
struct expr *expr;
struct occr *occr;
struct occr *avail;
??? The current algorithm is rather brute force.
Need to do some profiling. */
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash)
+ for (i = 0; i < expr_hash_table.size; i++)
+ for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash)
{
/* If the basic block isn't reachable, PPOUT will be TRUE. However,
we don't want to insert a copy here because the expression may not
expression wasn't deleted anywhere. */
if (expr->reaching_reg == NULL)
continue;
+
+ /* Set when we add a copy for that expression. */
+ added_copy = 0;
for (occr = expr->antic_occr; occr != NULL; occr = occr->next)
{
BLOCK_FOR_INSN (occr->insn)))
continue;
+ added_copy = 1;
+
/* Copy the result of avail to reaching_reg. */
pre_insert_copy_insn (expr, insn);
avail->copied_p = 1;
}
}
+
+ if (added_copy)
+ update_ld_motion_stores (expr);
}
}
/* Emit move from SRC to DEST noting the equivalence with expression computed
in INSN. */
static rtx
-gcse_emit_move_after (src, dest, insn)
- rtx src, dest, insn;
+gcse_emit_move_after (rtx src, rtx dest, rtx insn)
{
rtx new;
rtx set = single_set (insn), set2;
else
eqv = SET_SRC (set);
- set_unique_reg_note (new, REG_EQUAL, copy_insn_1 (src));
+ set_unique_reg_note (new, REG_EQUAL, copy_insn_1 (eqv));
return new;
}
the expression into the result of the SET. It is left to later passes
(cprop, cse2, flow, combine, regmove) to propagate the copy or eliminate it.
- Returns non-zero if a change is made. */
+ Returns nonzero if a change is made. */
static int
-pre_delete ()
+pre_delete (void)
{
unsigned int i;
int changed;
struct occr *occr;
changed = 0;
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash)
+ for (i = 0; i < expr_hash_table.size; i++)
+ for (expr = expr_hash_table.table[i];
+ expr != NULL;
+ expr = expr->next_same_hash)
{
int indx = expr->bitmap_index;
rtx set;
basic_block bb = BLOCK_FOR_INSN (insn);
- if (TEST_BIT (pre_delete_map[bb->index], indx))
+ /* We only delete insns that have a single_set. */
+ if (TEST_BIT (pre_delete_map[bb->index], indx)
+ && (set = single_set (insn)) != 0)
{
- set = single_set (insn);
- if (! set)
- abort ();
-
/* Create a pseudo-reg to store the result of reaching
expressions into. Get the mode for the new pseudo from
the mode of the original destination pseudo. */
redundancies. */
static int
-pre_gcse ()
+pre_gcse (void)
{
unsigned int i;
int did_insert, changed;
/* Compute a mapping from expression number (`bitmap_index') to
hash table entry. */
- index_map = (struct expr **) xcalloc (n_exprs, sizeof (struct expr *));
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash)
+ index_map = xcalloc (expr_hash_table.n_elems, sizeof (struct expr *));
+ for (i = 0; i < expr_hash_table.size; i++)
+ for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash)
index_map[expr->bitmap_index] = expr;
/* Reset bitmap used to track which insns are redundant. */
/* Top level routine to perform one PRE GCSE pass.
- Return non-zero if a change was made. */
+ Return nonzero if a change was made. */
static int
-one_pre_gcse_pass (pass)
- int pass;
+one_pre_gcse_pass (int pass)
{
int changed = 0;
gcse_subst_count = 0;
gcse_create_count = 0;
- alloc_expr_hash_table (max_cuid);
+ alloc_hash_table (max_cuid, &expr_hash_table, 0);
add_noreturn_fake_exit_edges ();
if (flag_gcse_lm)
compute_ld_motion_mems ();
- compute_expr_hash_table ();
+ compute_hash_table (&expr_hash_table);
trim_ld_motion_mems ();
if (gcse_file)
- dump_hash_table (gcse_file, "Expression", expr_hash_table,
- expr_hash_table_size, n_exprs);
+ dump_hash_table (gcse_file, "Expression", &expr_hash_table);
- if (n_exprs > 0)
+ if (expr_hash_table.n_elems > 0)
{
- alloc_pre_mem (last_basic_block, n_exprs);
+ alloc_pre_mem (last_basic_block, expr_hash_table.n_elems);
compute_pre_data ();
changed |= pre_gcse ();
free_edge_list (edge_list);
free_ldst_mems ();
remove_fake_edges ();
- free_expr_hash_table ();
+ free_hash_table (&expr_hash_table);
if (gcse_file)
{
fprintf (gcse_file, "\nPRE GCSE of %s, pass %d: %d bytes needed, ",
- current_function_name, pass, bytes_used);
+ current_function_name (), pass, bytes_used);
fprintf (gcse_file, "%d substs, %d insns created\n",
gcse_subst_count, gcse_create_count);
}
necessary REG_LABEL notes. */
static void
-add_label_notes (x, insn)
- rtx x;
- rtx insn;
+add_label_notes (rtx x, rtx insn)
{
enum rtx_code code = GET_CODE (x);
int i, j;
if (code == LABEL_REF && !LABEL_REF_NONLOCAL_P (x))
{
/* This code used to ignore labels that referred to dispatch tables to
- avoid flow generating (slighly) worse code.
+ avoid flow generating (slightly) worse code.
We no longer ignore such label references (see LABEL_REF handling in
mark_jump_label for additional information). */
EH table sizes, this may not be worthwhile. */
static void
-compute_transpout ()
+compute_transpout (void)
{
basic_block bb;
unsigned int i;
/* Note that flow inserted a nop a the end of basic blocks that
end in call instructions for reasons other than abnormal
control flow. */
- if (GET_CODE (bb->end) != CALL_INSN)
+ if (GET_CODE (BB_END (bb)) != CALL_INSN)
continue;
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr ; expr = expr->next_same_hash)
+ for (i = 0; i < expr_hash_table.size; i++)
+ for (expr = expr_hash_table.table[i]; expr ; expr = expr->next_same_hash)
if (GET_CODE (expr->expr) == MEM)
{
if (GET_CODE (XEXP (expr->expr, 0)) == SYMBOL_REF
We ignore hard registers. */
static void
-invalidate_nonnull_info (x, setter, data)
- rtx x;
- rtx setter ATTRIBUTE_UNUSED;
- void *data;
+invalidate_nonnull_info (rtx x, rtx setter ATTRIBUTE_UNUSED, void *data)
{
unsigned int regno;
struct null_pointer_info *npi = (struct null_pointer_info *) data;
they are not our responsibility to free. */
static int
-delete_null_pointer_checks_1 (block_reg, nonnull_avin,
- nonnull_avout, npi)
- unsigned int *block_reg;
- sbitmap *nonnull_avin;
- sbitmap *nonnull_avout;
- struct null_pointer_info *npi;
+delete_null_pointer_checks_1 (unsigned int *block_reg, sbitmap *nonnull_avin,
+ sbitmap *nonnull_avout,
+ struct null_pointer_info *npi)
{
basic_block bb, current_block;
sbitmap *nonnull_local = npi->nonnull_local;
/* Scan each insn in the basic block looking for memory references and
register sets. */
- stop_insn = NEXT_INSN (current_block->end);
- for (insn = current_block->head;
+ stop_insn = NEXT_INSN (BB_HEAD (current_block));
+ for (insn = BB_HEAD (current_block);
insn != stop_insn;
insn = NEXT_INSN (insn))
{
}
/* Now compute global properties based on the local properties. This
- is a classic global availablity algorithm. */
+ is a classic global availability algorithm. */
compute_available (nonnull_local, nonnull_killed,
nonnull_avout, nonnull_avin);
against zero. */
FOR_EACH_BB (bb)
{
- rtx last_insn = bb->end;
+ rtx last_insn = BB_END (bb);
rtx condition, earliest;
int compare_and_branch;
continue;
/* LAST_INSN is a conditional jump. Get its condition. */
- condition = get_condition (last_insn, &earliest);
+ condition = get_condition (last_insn, &earliest, false);
/* If we can't determine the condition then skip. */
if (! condition)
delete_insn (earliest);
purge_dead_edges (bb);
- /* Don't check this block again. (Note that BLOCK_END is
+ /* Don't check this block again. (Note that BB_END is
invalid here; we deleted the last instruction in the
block.) */
block_reg[bb->index] = 0;
reference of that form, then we know the register can not have the value
zero at the conditional branch.
- So we merely need to compute the local properies and propagate that data
+ So we merely need to compute the local properties and propagate that data
around the cfg, then optimize where possible.
We run this pass two times. Once before CSE, then again after CSE. This
This could probably be integrated with global cprop with a little work. */
int
-delete_null_pointer_checks (f)
- rtx f ATTRIBUTE_UNUSED;
+delete_null_pointer_checks (rtx f ATTRIBUTE_UNUSED)
{
sbitmap *nonnull_avin, *nonnull_avout;
unsigned int *block_reg;
basic_block bb;
int reg;
int regs_per_pass;
- int max_reg;
+ int max_reg = max_reg_num ();
struct null_pointer_info npi;
int something_changed = 0;
- /* If we have only a single block, then there's nothing to do. */
- if (n_basic_blocks <= 1)
- return 0;
-
- /* Trying to perform global optimizations on flow graphs which have
- a high connectivity will take a long time and is unlikely to be
- particularly useful.
-
- In normal circumstances a cfg should have about twice as many edges
- as blocks. But we do not want to punish small functions which have
- a couple switch statements. So we require a relatively large number
- of basic blocks and the ratio of edges to blocks to be high. */
- if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20)
+ /* If we have only a single block, or it is too expensive, give up. */
+ if (n_basic_blocks <= 1
+ || is_too_expensive (_ ("NULL pointer checks disabled")))
return 0;
/* We need four bitmaps, each with a bit for each register in each
basic block. */
- max_reg = max_reg_num ();
regs_per_pass = get_bitmap_width (4, last_basic_block, max_reg);
/* Allocate bitmaps to hold local and global properties. */
/* Go through the basic blocks, seeing whether or not each block
ends with a conditional branch whose condition is a comparison
against zero. Record the register compared in BLOCK_REG. */
- block_reg = (unsigned int *) xcalloc (last_basic_block, sizeof (int));
+ block_reg = xcalloc (last_basic_block, sizeof (int));
FOR_EACH_BB (bb)
{
- rtx last_insn = bb->end;
+ rtx last_insn = BB_END (bb);
rtx condition, earliest, reg;
/* We only want conditional branches. */
continue;
/* LAST_INSN is a conditional jump. Get its condition. */
- condition = get_condition (last_insn, &earliest);
+ condition = get_condition (last_insn, &earliest, false);
/* If we were unable to get the condition, or it is not an equality
comparison against zero then there's nothing we can do. */
/* Hoistable expressions. */
static sbitmap *hoist_exprs;
-/* Dominator bitmaps. */
-dominance_info dominators;
-
/* ??? We could compute post dominators and run this algorithm in
- reverse to to perform tail merging, doing so would probably be
+ reverse to perform tail merging, doing so would probably be
more effective than the tail merging code in jump.c.
It's unclear if tail merging could be run in parallel with
/* Allocate vars used for code hoisting analysis. */
static void
-alloc_code_hoist_mem (n_blocks, n_exprs)
- int n_blocks, n_exprs;
+alloc_code_hoist_mem (int n_blocks, int n_exprs)
{
antloc = sbitmap_vector_alloc (n_blocks, n_exprs);
transp = sbitmap_vector_alloc (n_blocks, n_exprs);
/* Free vars used for code hoisting analysis. */
static void
-free_code_hoist_mem ()
+free_code_hoist_mem (void)
{
sbitmap_vector_free (antloc);
sbitmap_vector_free (transp);
sbitmap_vector_free (hoist_exprs);
sbitmap_vector_free (transpout);
- free_dominance_info (dominators);
+ free_dominance_info (CDI_DOMINATORS);
}
/* Compute the very busy expressions at entry/exit from each block.
compute the expression. */
static void
-compute_code_hoist_vbeinout ()
+compute_code_hoist_vbeinout (void)
{
int changed, passes;
basic_block bb;
/* Top level routine to do the dataflow analysis needed by code hoisting. */
static void
-compute_code_hoist_data ()
+compute_code_hoist_data (void)
{
- compute_local_properties (transp, comp, antloc, 0);
+ compute_local_properties (transp, comp, antloc, &expr_hash_table);
compute_transpout ();
compute_code_hoist_vbeinout ();
- dominators = calculate_dominance_info (CDI_DOMINATORS);
+ calculate_dominance_info (CDI_DOMINATORS);
if (gcse_file)
fprintf (gcse_file, "\n");
}
paths. */
static int
-hoist_expr_reaches_here_p (expr_bb, expr_index, bb, visited)
- basic_block expr_bb;
- int expr_index;
- basic_block bb;
- char *visited;
+hoist_expr_reaches_here_p (basic_block expr_bb, int expr_index, basic_block bb, char *visited)
{
edge pred;
int visited_allocated_locally = 0;
if (pred->src == ENTRY_BLOCK_PTR)
break;
+ else if (pred_bb == expr_bb)
+ continue;
else if (visited[pred_bb->index])
continue;
/* Actually perform code hoisting. */
static void
-hoist_code ()
+hoist_code (void)
{
basic_block bb, dominated;
basic_block *domby;
/* Compute a mapping from expression number (`bitmap_index') to
hash table entry. */
- index_map = (struct expr **) xcalloc (n_exprs, sizeof (struct expr *));
- for (i = 0; i < expr_hash_table_size; i++)
- for (expr = expr_hash_table[i]; expr != NULL; expr = expr->next_same_hash)
+ index_map = xcalloc (expr_hash_table.n_elems, sizeof (struct expr *));
+ for (i = 0; i < expr_hash_table.size; i++)
+ for (expr = expr_hash_table.table[i]; expr != NULL; expr = expr->next_same_hash)
index_map[expr->bitmap_index] = expr;
/* Walk over each basic block looking for potentially hoistable
int found = 0;
int insn_inserted_p;
- domby_len = get_dominated_by (dominators, bb, &domby);
+ domby_len = get_dominated_by (CDI_DOMINATORS, bb, &domby);
/* Examine each expression that is very busy at the exit of this
block. These are the potentially hoistable expressions. */
for (i = 0; i < hoist_vbeout[bb->index]->n_bits; i++)
to avoid any possible code expansion due to register
allocation issues; however experiments have shown that
the vast majority of hoistable expressions are only movable
- from two successors, so raising this threshhold is likely
+ from two successors, so raising this threshold is likely
to nullify any benefit we get from code hoisting. */
if (hoistable > 1)
{
/* If we found nothing to hoist, then quit now. */
if (! found)
{
- free (domby);
+ free (domby);
continue;
}
/* Top level routine to perform one code hoisting (aka unification) pass
- Return non-zero if a change was made. */
+ Return nonzero if a change was made. */
static int
-one_code_hoisting_pass ()
+one_code_hoisting_pass (void)
{
int changed = 0;
- alloc_expr_hash_table (max_cuid);
- compute_expr_hash_table ();
+ alloc_hash_table (max_cuid, &expr_hash_table, 0);
+ compute_hash_table (&expr_hash_table);
if (gcse_file)
- dump_hash_table (gcse_file, "Code Hosting Expressions", expr_hash_table,
- expr_hash_table_size, n_exprs);
+ dump_hash_table (gcse_file, "Code Hosting Expressions", &expr_hash_table);
- if (n_exprs > 0)
+ if (expr_hash_table.n_elems > 0)
{
- alloc_code_hoist_mem (last_basic_block, n_exprs);
+ alloc_code_hoist_mem (last_basic_block, expr_hash_table.n_elems);
compute_code_hoist_data ();
hoist_code ();
free_code_hoist_mem ();
}
- free_expr_hash_table ();
+ free_hash_table (&expr_hash_table);
return changed;
}
doesn't find one, we create one and initialize it. */
static struct ls_expr *
-ldst_entry (x)
- rtx x;
+ldst_entry (rtx x)
{
+ int do_not_record_p = 0;
struct ls_expr * ptr;
+ unsigned int hash;
- for (ptr = first_ls_expr(); ptr != NULL; ptr = next_ls_expr (ptr))
- if (expr_equiv_p (ptr->pattern, x))
- break;
+ hash = hash_expr_1 (x, GET_MODE (x), & do_not_record_p);
- if (!ptr)
- {
- ptr = (struct ls_expr *) xmalloc (sizeof (struct ls_expr));
+ for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next)
+ if (ptr->hash_index == hash && expr_equiv_p (ptr->pattern, x))
+ return ptr;
- ptr->next = pre_ldst_mems;
- ptr->expr = NULL;
- ptr->pattern = x;
- ptr->loads = NULL_RTX;
- ptr->stores = NULL_RTX;
- ptr->reaching_reg = NULL_RTX;
- ptr->invalid = 0;
- ptr->index = 0;
- ptr->hash_index = 0;
- pre_ldst_mems = ptr;
- }
+ ptr = xmalloc (sizeof (struct ls_expr));
+
+ ptr->next = pre_ldst_mems;
+ ptr->expr = NULL;
+ ptr->pattern = x;
+ ptr->pattern_regs = NULL_RTX;
+ ptr->loads = NULL_RTX;
+ ptr->stores = NULL_RTX;
+ ptr->reaching_reg = NULL_RTX;
+ ptr->invalid = 0;
+ ptr->index = 0;
+ ptr->hash_index = hash;
+ pre_ldst_mems = ptr;
return ptr;
}
/* Free up an individual ldst entry. */
static void
-free_ldst_entry (ptr)
- struct ls_expr * ptr;
+free_ldst_entry (struct ls_expr * ptr)
{
free_INSN_LIST_list (& ptr->loads);
free_INSN_LIST_list (& ptr->stores);
/* Free up all memory associated with the ldst list. */
static void
-free_ldst_mems ()
+free_ldst_mems (void)
{
while (pre_ldst_mems)
{
/* Dump debugging info about the ldst list. */
static void
-print_ldst_list (file)
- FILE * file;
+print_ldst_list (FILE * file)
{
struct ls_expr * ptr;
/* Returns 1 if X is in the list of ldst only expressions. */
static struct ls_expr *
-find_rtx_in_ldst (x)
- rtx x;
+find_rtx_in_ldst (rtx x)
{
struct ls_expr * ptr;
/* Assign each element of the list of mems a monotonically increasing value. */
static int
-enumerate_ldsts ()
+enumerate_ldsts (void)
{
struct ls_expr * ptr;
int n = 0;
/* Return first item in the list. */
static inline struct ls_expr *
-first_ls_expr ()
+first_ls_expr (void)
{
return pre_ldst_mems;
}
-/* Return the next item in ther list after the specified one. */
+/* Return the next item in the list after the specified one. */
static inline struct ls_expr *
-next_ls_expr (ptr)
- struct ls_expr * ptr;
+next_ls_expr (struct ls_expr * ptr)
{
return ptr->next;
}
ld_motion list, otherwise we let the usual aliasing take care of it. */
static int
-simple_mem (x)
- rtx x;
+simple_mem (rtx x)
{
if (GET_CODE (x) != MEM)
return 0;
if (GET_MODE (x) == BLKmode)
return 0;
- if (!rtx_varies_p (XEXP (x, 0), 0))
- return 1;
+ /* If we are handling exceptions, we must be careful with memory references
+ that may trap. If we are not, the behavior is undefined, so we may just
+ continue. */
+ if (flag_non_call_exceptions && may_trap_p (x))
+ return 0;
- return 0;
+ if (side_effects_p (x))
+ return 0;
+
+ /* Do not consider function arguments passed on stack. */
+ if (reg_mentioned_p (stack_pointer_rtx, x))
+ return 0;
+
+ if (flag_float_store && FLOAT_MODE_P (GET_MODE (x)))
+ return 0;
+
+ return 1;
}
/* Make sure there isn't a buried reference in this pattern anywhere.
fix it up. */
static void
-invalidate_any_buried_refs (x)
- rtx x;
+invalidate_any_buried_refs (rtx x)
{
const char * fmt;
int i, j;
}
}
-/* Find all the 'simple' MEMs which are used in LOADs and STORES. Simple
- being defined as MEM loads and stores to symbols, with no
- side effects and no registers in the expression. If there are any
- uses/defs which don't match this criteria, it is invalidated and
- trimmed out later. */
+/* Find all the 'simple' MEMs which are used in LOADs and STORES. Simple
+ being defined as MEM loads and stores to symbols, with no side effects
+ and no registers in the expression. For a MEM destination, we also
+ check that the insn is still valid if we replace the destination with a
+ REG, as is done in update_ld_motion_stores. If there are any uses/defs
+ which don't match this criteria, they are invalidated and trimmed out
+ later. */
static void
-compute_ld_motion_mems ()
+compute_ld_motion_mems (void)
{
struct ls_expr * ptr;
basic_block bb;
FOR_EACH_BB (bb)
{
- for (insn = bb->head;
- insn && insn != NEXT_INSN (bb->end);
+ for (insn = BB_HEAD (bb);
+ insn && insn != NEXT_INSN (BB_END (bb));
insn = NEXT_INSN (insn))
{
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
+ if (INSN_P (insn))
{
if (GET_CODE (PATTERN (insn)) == SET)
{
ptr = ldst_entry (dest);
if (GET_CODE (src) != MEM
- && GET_CODE (src) != ASM_OPERANDS)
+ && GET_CODE (src) != ASM_OPERANDS
+ /* Check for REG manually since want_to_gcse_p
+ returns 0 for all REGs. */
+ && (REG_P (src) || want_to_gcse_p (src)))
ptr->stores = alloc_INSN_LIST (insn, ptr->stores);
else
ptr->invalid = 1;
expression list for pre gcse. */
static void
-trim_ld_motion_mems ()
+trim_ld_motion_mems (void)
{
- struct ls_expr * last = NULL;
- struct ls_expr * ptr = first_ls_expr ();
+ struct ls_expr * * last = & pre_ldst_mems;
+ struct ls_expr * ptr = pre_ldst_mems;
while (ptr != NULL)
{
- int del = ptr->invalid;
- struct expr * expr = NULL;
+ struct expr * expr;
/* Delete if entry has been made invalid. */
- if (!del)
+ if (! ptr->invalid)
{
- unsigned int i;
-
- del = 1;
/* Delete if we cannot find this mem in the expression list. */
- for (i = 0; i < expr_hash_table_size && del; i++)
- {
- for (expr = expr_hash_table[i];
- expr != NULL;
- expr = expr->next_same_hash)
- if (expr_equiv_p (expr->expr, ptr->pattern))
- {
- del = 0;
- break;
- }
- }
- }
+ unsigned int hash = ptr->hash_index % expr_hash_table.size;
- if (del)
- {
- if (last != NULL)
- {
- last->next = ptr->next;
- free_ldst_entry (ptr);
- ptr = last->next;
- }
- else
- {
- pre_ldst_mems = pre_ldst_mems->next;
- free_ldst_entry (ptr);
- ptr = pre_ldst_mems;
- }
+ for (expr = expr_hash_table.table[hash];
+ expr != NULL;
+ expr = expr->next_same_hash)
+ if (expr_equiv_p (expr->expr, ptr->pattern))
+ break;
}
else
+ expr = (struct expr *) 0;
+
+ if (expr)
{
/* Set the expression field if we are keeping it. */
- last = ptr;
ptr->expr = expr;
+ last = & ptr->next;
ptr = ptr->next;
}
+ else
+ {
+ *last = ptr->next;
+ free_ldst_entry (ptr);
+ ptr = * last;
+ }
}
/* Show the world what we've found. */
/* This routine will take an expression which we are replacing with
a reaching register, and update any stores that are needed if
that expression is in the ld_motion list. Stores are updated by
- copying their SRC to the reaching register, and then storeing
+ copying their SRC to the reaching register, and then storing
the reaching register into the store location. These keeps the
correct value in the reaching register for the loads. */
static void
-update_ld_motion_stores (expr)
- struct expr * expr;
+update_ld_motion_stores (struct expr * expr)
{
struct ls_expr * mem_ptr;
matter to set the reaching reg everywhere... some might be
dead and should be eliminated later. */
- /* We replace SET mem = expr with
- SET reg = expr
- SET mem = reg , where reg is the
- reaching reg used in the load. */
+ /* We replace (set mem expr) with (set reg expr) (set mem reg)
+ where reg is the reaching reg used in the load. We checked in
+ compute_ld_motion_mems that we can replace (set mem expr) with
+ (set reg expr) in that insn. */
rtx list = mem_ptr->stores;
for ( ; list != NULL_RTX; list = XEXP (list, 1))
fprintf (gcse_file, "\n");
}
- copy = gen_move_insn ( reg, SET_SRC (pat));
+ copy = gen_move_insn ( reg, copy_rtx (SET_SRC (pat)));
new = emit_insn_before (copy, insn);
record_one_set (REGNO (reg), new);
SET_SRC (pat) = reg;
\f
/* Store motion code. */
+#define ANTIC_STORE_LIST(x) ((x)->loads)
+#define AVAIL_STORE_LIST(x) ((x)->stores)
+#define LAST_AVAIL_CHECK_FAILURE(x) ((x)->reaching_reg)
+
/* This is used to communicate the target bitvector we want to use in the
reg_set_info routine when called via the note_stores mechanism. */
-static sbitmap * regvec;
+static int * regvec;
+
+/* And current insn, for the same routine. */
+static rtx compute_store_table_current_insn;
/* Used in computing the reverse edge graph bit vectors. */
static sbitmap * st_antloc;
/* Global holding the number of store expressions we are dealing with. */
static int num_stores;
-/* Checks to set if we need to mark a register set. Called from note_stores. */
+/* Checks to set if we need to mark a register set. Called from
+ note_stores. */
static void
-reg_set_info (dest, setter, data)
- rtx dest, setter ATTRIBUTE_UNUSED;
- void * data ATTRIBUTE_UNUSED;
+reg_set_info (rtx dest, rtx setter ATTRIBUTE_UNUSED,
+ void *data)
{
+ sbitmap bb_reg = data;
+
if (GET_CODE (dest) == SUBREG)
dest = SUBREG_REG (dest);
if (GET_CODE (dest) == REG)
- SET_BIT (*regvec, REGNO (dest));
+ {
+ regvec[REGNO (dest)] = INSN_UID (compute_store_table_current_insn);
+ if (bb_reg)
+ SET_BIT (bb_reg, REGNO (dest));
+ }
}
-/* Return non-zero if the register operands of expression X are killed
- anywhere in basic block BB. */
+/* Clear any mark that says that this insn sets dest. Called from
+ note_stores. */
-static int
-store_ops_ok (x, bb)
- rtx x;
- basic_block bb;
+static void
+reg_clear_last_set (rtx dest, rtx setter ATTRIBUTE_UNUSED,
+ void *data)
+{
+ int *dead_vec = data;
+
+ if (GET_CODE (dest) == SUBREG)
+ dest = SUBREG_REG (dest);
+
+ if (GET_CODE (dest) == REG &&
+ dead_vec[REGNO (dest)] == INSN_UID (compute_store_table_current_insn))
+ dead_vec[REGNO (dest)] = 0;
+}
+
+/* Return zero if some of the registers in list X are killed
+ due to set of registers in bitmap REGS_SET. */
+
+static bool
+store_ops_ok (rtx x, int *regs_set)
+{
+ rtx reg;
+
+ for (; x; x = XEXP (x, 1))
+ {
+ reg = XEXP (x, 0);
+ if (regs_set[REGNO(reg)])
+ return false;
+ }
+
+ return true;
+}
+
+/* Returns a list of registers mentioned in X. */
+static rtx
+extract_mentioned_regs (rtx x)
+{
+ return extract_mentioned_regs_helper (x, NULL_RTX);
+}
+
+/* Helper for extract_mentioned_regs; ACCUM is used to accumulate used
+ registers. */
+static rtx
+extract_mentioned_regs_helper (rtx x, rtx accum)
{
int i;
enum rtx_code code;
repeat:
if (x == 0)
- return 1;
+ return accum;
code = GET_CODE (x);
switch (code)
{
case REG:
- /* If a reg has changed after us in this
- block, the operand has been killed. */
- return TEST_BIT (reg_set_in_block[bb->index], REGNO (x));
+ return alloc_EXPR_LIST (0, x, accum);
case MEM:
x = XEXP (x, 0);
case PRE_INC:
case POST_DEC:
case POST_INC:
- return 0;
+ /* We do not run this function with arguments having side effects. */
+ abort ();
case PC:
case CC0: /*FIXME*/
case LABEL_REF:
case ADDR_VEC:
case ADDR_DIFF_VEC:
- return 1;
+ return accum;
default:
break;
rtx tem = XEXP (x, i);
/* If we are about to do the last recursive call
- needed at this level, change it into iteration.
- This function is called enough to be worth it. */
+ needed at this level, change it into iteration. */
if (i == 0)
{
x = tem;
goto repeat;
}
- if (! store_ops_ok (tem, bb))
- return 0;
+ accum = extract_mentioned_regs_helper (tem, accum);
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
- {
- if (! store_ops_ok (XVECEXP (x, i, j), bb))
- return 0;
- }
+ accum = extract_mentioned_regs_helper (XVECEXP (x, i, j), accum);
}
}
- return 1;
+ return accum;
}
-/* Determine whether insn is MEM store pattern that we will consider moving. */
+/* Determine whether INSN is MEM store pattern that we will consider moving.
+ REGS_SET_BEFORE is bitmap of registers set before (and including) the
+ current insn, REGS_SET_AFTER is bitmap of registers set after (and
+ including) the insn in this basic block. We must be passing through BB from
+ head to end, as we are using this fact to speed things up.
+
+ The results are stored this way:
+
+ -- the first anticipatable expression is added into ANTIC_STORE_LIST
+ -- if the processed expression is not anticipatable, NULL_RTX is added
+ there instead, so that we can use it as indicator that no further
+ expression of this type may be anticipatable
+ -- if the expression is available, it is added as head of AVAIL_STORE_LIST;
+ consequently, all of them but this head are dead and may be deleted.
+ -- if the expression is not available, the insn due to that it fails to be
+ available is stored in reaching_reg.
+
+ The things are complicated a bit by fact that there already may be stores
+ to the same MEM from other blocks; also caller must take care of the
+ necessary cleanup of the temporary markers after end of the basic block.
+ */
static void
-find_moveable_store (insn)
- rtx insn;
+find_moveable_store (rtx insn, int *regs_set_before, int *regs_set_after)
{
struct ls_expr * ptr;
- rtx dest = PATTERN (insn);
+ rtx dest, set, tmp;
+ int check_anticipatable, check_available;
+ basic_block bb = BLOCK_FOR_INSN (insn);
- if (GET_CODE (dest) != SET
- || GET_CODE (SET_SRC (dest)) == ASM_OPERANDS)
+ set = single_set (insn);
+ if (!set)
return;
- dest = SET_DEST (dest);
+ dest = SET_DEST (set);
if (GET_CODE (dest) != MEM || MEM_VOLATILE_P (dest)
|| GET_MODE (dest) == BLKmode)
return;
- if (GET_CODE (XEXP (dest, 0)) != SYMBOL_REF)
- return;
+ if (side_effects_p (dest))
+ return;
- if (rtx_varies_p (XEXP (dest, 0), 0))
+ /* If we are handling exceptions, we must be careful with memory references
+ that may trap. If we are not, the behavior is undefined, so we may just
+ continue. */
+ if (flag_non_call_exceptions && may_trap_p (dest))
return;
ptr = ldst_entry (dest);
- ptr->stores = alloc_INSN_LIST (insn, ptr->stores);
+ if (!ptr->pattern_regs)
+ ptr->pattern_regs = extract_mentioned_regs (dest);
+
+ /* Do not check for anticipatability if we either found one anticipatable
+ store already, or tested for one and found out that it was killed. */
+ check_anticipatable = 0;
+ if (!ANTIC_STORE_LIST (ptr))
+ check_anticipatable = 1;
+ else
+ {
+ tmp = XEXP (ANTIC_STORE_LIST (ptr), 0);
+ if (tmp != NULL_RTX
+ && BLOCK_FOR_INSN (tmp) != bb)
+ check_anticipatable = 1;
+ }
+ if (check_anticipatable)
+ {
+ if (store_killed_before (dest, ptr->pattern_regs, insn, bb, regs_set_before))
+ tmp = NULL_RTX;
+ else
+ tmp = insn;
+ ANTIC_STORE_LIST (ptr) = alloc_INSN_LIST (tmp,
+ ANTIC_STORE_LIST (ptr));
+ }
+
+ /* It is not necessary to check whether store is available if we did
+ it successfully before; if we failed before, do not bother to check
+ until we reach the insn that caused us to fail. */
+ check_available = 0;
+ if (!AVAIL_STORE_LIST (ptr))
+ check_available = 1;
+ else
+ {
+ tmp = XEXP (AVAIL_STORE_LIST (ptr), 0);
+ if (BLOCK_FOR_INSN (tmp) != bb)
+ check_available = 1;
+ }
+ if (check_available)
+ {
+ /* Check that we have already reached the insn at that the check
+ failed last time. */
+ if (LAST_AVAIL_CHECK_FAILURE (ptr))
+ {
+ for (tmp = BB_END (bb);
+ tmp != insn && tmp != LAST_AVAIL_CHECK_FAILURE (ptr);
+ tmp = PREV_INSN (tmp))
+ continue;
+ if (tmp == insn)
+ check_available = 0;
+ }
+ else
+ check_available = store_killed_after (dest, ptr->pattern_regs, insn,
+ bb, regs_set_after,
+ &LAST_AVAIL_CHECK_FAILURE (ptr));
+ }
+ if (!check_available)
+ AVAIL_STORE_LIST (ptr) = alloc_INSN_LIST (insn, AVAIL_STORE_LIST (ptr));
}
-/* Perform store motion. Much like gcse, except we move expressions the
- other way by looking at the flowgraph in reverse. */
+/* Find available and anticipatable stores. */
static int
-compute_store_table ()
+compute_store_table (void)
{
int ret;
basic_block bb;
unsigned regno;
- rtx insn, pat;
+ rtx insn, pat, tmp;
+ int *last_set_in, *already_set;
+ struct ls_expr * ptr, **prev_next_ptr_ptr;
max_gcse_regno = max_reg_num ();
- reg_set_in_block = (sbitmap *) sbitmap_vector_alloc (last_basic_block,
+ reg_set_in_block = sbitmap_vector_alloc (last_basic_block,
max_gcse_regno);
sbitmap_vector_zero (reg_set_in_block, last_basic_block);
pre_ldst_mems = 0;
+ last_set_in = xcalloc (max_gcse_regno, sizeof (int));
+ already_set = xmalloc (sizeof (int) * max_gcse_regno);
/* Find all the stores we care about. */
FOR_EACH_BB (bb)
{
- regvec = & (reg_set_in_block[bb->index]);
- for (insn = bb->end;
- insn && insn != PREV_INSN (bb->end);
- insn = PREV_INSN (insn))
+ /* First compute the registers set in this block. */
+ regvec = last_set_in;
+
+ for (insn = BB_HEAD (bb);
+ insn != NEXT_INSN (BB_END (bb));
+ insn = NEXT_INSN (insn))
{
- /* Ignore anything that is not a normal insn. */
if (! INSN_P (insn))
continue;
for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
if (clobbers_all
|| TEST_HARD_REG_BIT (regs_invalidated_by_call, regno))
- SET_BIT (reg_set_in_block[bb->index], regno);
+ {
+ last_set_in[regno] = INSN_UID (insn);
+ SET_BIT (reg_set_in_block[bb->index], regno);
+ }
+ }
+
+ pat = PATTERN (insn);
+ compute_store_table_current_insn = insn;
+ note_stores (pat, reg_set_info, reg_set_in_block[bb->index]);
+ }
+
+ /* Now find the stores. */
+ memset (already_set, 0, sizeof (int) * max_gcse_regno);
+ regvec = already_set;
+ for (insn = BB_HEAD (bb);
+ insn != NEXT_INSN (BB_END (bb));
+ insn = NEXT_INSN (insn))
+ {
+ if (! INSN_P (insn))
+ continue;
+
+ if (GET_CODE (insn) == CALL_INSN)
+ {
+ bool clobbers_all = false;
+#ifdef NON_SAVING_SETJMP
+ if (NON_SAVING_SETJMP
+ && find_reg_note (insn, REG_SETJMP, NULL_RTX))
+ clobbers_all = true;
+#endif
+
+ for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+ if (clobbers_all
+ || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno))
+ already_set[regno] = 1;
}
pat = PATTERN (insn);
note_stores (pat, reg_set_info, NULL);
/* Now that we've marked regs, look for stores. */
- if (GET_CODE (pat) == SET)
- find_moveable_store (insn);
+ find_moveable_store (insn, already_set, last_set_in);
+
+ /* Unmark regs that are no longer set. */
+ compute_store_table_current_insn = insn;
+ note_stores (pat, reg_clear_last_set, last_set_in);
+ if (GET_CODE (insn) == CALL_INSN)
+ {
+ bool clobbers_all = false;
+#ifdef NON_SAVING_SETJMP
+ if (NON_SAVING_SETJMP
+ && find_reg_note (insn, REG_SETJMP, NULL_RTX))
+ clobbers_all = true;
+#endif
+
+ for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
+ if ((clobbers_all
+ || TEST_HARD_REG_BIT (regs_invalidated_by_call, regno))
+ && last_set_in[regno] == INSN_UID (insn))
+ last_set_in[regno] = 0;
+ }
+ }
+
+#ifdef ENABLE_CHECKING
+ /* last_set_in should now be all-zero. */
+ for (regno = 0; regno < max_gcse_regno; regno++)
+ if (last_set_in[regno] != 0)
+ abort ();
+#endif
+
+ /* Clear temporary marks. */
+ for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr))
+ {
+ LAST_AVAIL_CHECK_FAILURE(ptr) = NULL_RTX;
+ if (ANTIC_STORE_LIST (ptr)
+ && (tmp = XEXP (ANTIC_STORE_LIST (ptr), 0)) == NULL_RTX)
+ ANTIC_STORE_LIST (ptr) = XEXP (ANTIC_STORE_LIST (ptr), 1);
+ }
+ }
+
+ /* Remove the stores that are not available anywhere, as there will
+ be no opportunity to optimize them. */
+ for (ptr = pre_ldst_mems, prev_next_ptr_ptr = &pre_ldst_mems;
+ ptr != NULL;
+ ptr = *prev_next_ptr_ptr)
+ {
+ if (!AVAIL_STORE_LIST (ptr))
+ {
+ *prev_next_ptr_ptr = ptr->next;
+ free_ldst_entry (ptr);
}
+ else
+ prev_next_ptr_ptr = &ptr->next;
}
ret = enumerate_ldsts ();
if (gcse_file)
{
- fprintf (gcse_file, "Store Motion Expressions.\n");
+ fprintf (gcse_file, "ST_avail and ST_antic (shown under loads..)\n");
print_ldst_list (gcse_file);
}
+ free (last_set_in);
+ free (already_set);
return ret;
}
-/* Check to see if the load X is aliased with STORE_PATTERN. */
+/* Check to see if the load X is aliased with STORE_PATTERN.
+ AFTER is true if we are checking the case when STORE_PATTERN occurs
+ after the X. */
-static int
-load_kills_store (x, store_pattern)
- rtx x, store_pattern;
+static bool
+load_kills_store (rtx x, rtx store_pattern, int after)
{
- if (true_dependence (x, GET_MODE (x), store_pattern, rtx_addr_varies_p))
- return 1;
- return 0;
+ if (after)
+ return anti_dependence (x, store_pattern);
+ else
+ return true_dependence (store_pattern, GET_MODE (store_pattern), x,
+ rtx_addr_varies_p);
}
/* Go through the entire insn X, looking for any loads which might alias
- STORE_PATTERN. Return 1 if found. */
+ STORE_PATTERN. Return true if found.
+ AFTER is true if we are checking the case when STORE_PATTERN occurs
+ after the insn X. */
-static int
-find_loads (x, store_pattern)
- rtx x, store_pattern;
+static bool
+find_loads (rtx x, rtx store_pattern, int after)
{
const char * fmt;
int i, j;
- int ret = 0;
+ int ret = false;
if (!x)
- return 0;
+ return false;
if (GET_CODE (x) == SET)
x = SET_SRC (x);
if (GET_CODE (x) == MEM)
{
- if (load_kills_store (x, store_pattern))
- return 1;
+ if (load_kills_store (x, store_pattern, after))
+ return true;
}
/* Recursively process the insn. */
for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0 && !ret; i--)
{
if (fmt[i] == 'e')
- ret |= find_loads (XEXP (x, i), store_pattern);
+ ret |= find_loads (XEXP (x, i), store_pattern, after);
else if (fmt[i] == 'E')
for (j = XVECLEN (x, i) - 1; j >= 0; j--)
- ret |= find_loads (XVECEXP (x, i, j), store_pattern);
+ ret |= find_loads (XVECEXP (x, i, j), store_pattern, after);
}
return ret;
}
/* Check if INSN kills the store pattern X (is aliased with it).
- Return 1 if it it does. */
+ AFTER is true if we are checking the case when store X occurs
+ after the insn. Return true if it it does. */
-static int
-store_killed_in_insn (x, insn)
- rtx x, insn;
+static bool
+store_killed_in_insn (rtx x, rtx x_regs, rtx insn, int after)
{
- if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
- return 0;
+ rtx reg, base, note;
+
+ if (!INSN_P (insn))
+ return false;
if (GET_CODE (insn) == CALL_INSN)
{
/* A normal or pure call might read from pattern,
but a const call will not. */
- return ! CONST_OR_PURE_CALL_P (insn) || pure_call_p (insn);
+ if (! CONST_OR_PURE_CALL_P (insn) || pure_call_p (insn))
+ return true;
+
+ /* But even a const call reads its parameters. Check whether the
+ base of some of registers used in mem is stack pointer. */
+ for (reg = x_regs; reg; reg = XEXP (reg, 1))
+ {
+ base = find_base_term (XEXP (reg, 0));
+ if (!base
+ || (GET_CODE (base) == ADDRESS
+ && GET_MODE (base) == Pmode
+ && XEXP (base, 0) == stack_pointer_rtx))
+ return true;
+ }
+
+ return false;
}
if (GET_CODE (PATTERN (insn)) == SET)
{
rtx pat = PATTERN (insn);
+ rtx dest = SET_DEST (pat);
+
+ if (GET_CODE (dest) == SIGN_EXTRACT
+ || GET_CODE (dest) == ZERO_EXTRACT)
+ dest = XEXP (dest, 0);
+
/* Check for memory stores to aliased objects. */
- if (GET_CODE (SET_DEST (pat)) == MEM && !expr_equiv_p (SET_DEST (pat), x))
- /* pretend its a load and check for aliasing. */
- if (find_loads (SET_DEST (pat), x))
- return 1;
- return find_loads (SET_SRC (pat), x);
+ if (GET_CODE (dest) == MEM
+ && !expr_equiv_p (dest, x))
+ {
+ if (after)
+ {
+ if (output_dependence (dest, x))
+ return true;
+ }
+ else
+ {
+ if (output_dependence (x, dest))
+ return true;
+ }
+ }
+ if (find_loads (SET_SRC (pat), x, after))
+ return true;
}
- else
- return find_loads (PATTERN (insn), x);
+ else if (find_loads (PATTERN (insn), x, after))
+ return true;
+
+ /* If this insn has a REG_EQUAL or REG_EQUIV note referencing a memory
+ location aliased with X, then this insn kills X. */
+ note = find_reg_equal_equiv_note (insn);
+ if (! note)
+ return false;
+ note = XEXP (note, 0);
+
+ /* However, if the note represents a must alias rather than a may
+ alias relationship, then it does not kill X. */
+ if (expr_equiv_p (note, x))
+ return false;
+
+ /* See if there are any aliased loads in the note. */
+ return find_loads (note, x, after);
}
-/* Returns 1 if the expression X is loaded or clobbered on or after INSN
- within basic block BB. */
+/* Returns true if the expression X is loaded or clobbered on or after INSN
+ within basic block BB. REGS_SET_AFTER is bitmap of registers set in
+ or after the insn. X_REGS is list of registers mentioned in X. If the store
+ is killed, return the last insn in that it occurs in FAIL_INSN. */
-static int
-store_killed_after (x, insn, bb)
- rtx x, insn;
- basic_block bb;
+static bool
+store_killed_after (rtx x, rtx x_regs, rtx insn, basic_block bb,
+ int *regs_set_after, rtx *fail_insn)
{
- rtx last = bb->end;
-
- if (insn == last)
- return 0;
+ rtx last = BB_END (bb), act;
- /* Check if the register operands of the store are OK in this block.
- Note that if registers are changed ANYWHERE in the block, we'll
- decide we can't move it, regardless of whether it changed above
- or below the store. This could be improved by checking the register
- operands while lookinng for aliasing in each insn. */
- if (!store_ops_ok (XEXP (x, 0), bb))
- return 1;
+ if (!store_ops_ok (x_regs, regs_set_after))
+ {
+ /* We do not know where it will happen. */
+ if (fail_insn)
+ *fail_insn = NULL_RTX;
+ return true;
+ }
- for ( ; insn && insn != NEXT_INSN (last); insn = NEXT_INSN (insn))
- if (store_killed_in_insn (x, insn))
- return 1;
+ /* Scan from the end, so that fail_insn is determined correctly. */
+ for (act = last; act != PREV_INSN (insn); act = PREV_INSN (act))
+ if (store_killed_in_insn (x, x_regs, act, false))
+ {
+ if (fail_insn)
+ *fail_insn = act;
+ return true;
+ }
- return 0;
+ return false;
}
-/* Returns 1 if the expression X is loaded or clobbered on or before INSN
- within basic block BB. */
-static int
-store_killed_before (x, insn, bb)
- rtx x, insn;
- basic_block bb;
+/* Returns true if the expression X is loaded or clobbered on or before INSN
+ within basic block BB. X_REGS is list of registers mentioned in X.
+ REGS_SET_BEFORE is bitmap of registers set before or in this insn. */
+static bool
+store_killed_before (rtx x, rtx x_regs, rtx insn, basic_block bb,
+ int *regs_set_before)
{
- rtx first = bb->head;
+ rtx first = BB_HEAD (bb);
- if (insn == first)
- return store_killed_in_insn (x, insn);
+ if (!store_ops_ok (x_regs, regs_set_before))
+ return true;
- /* Check if the register operands of the store are OK in this block.
- Note that if registers are changed ANYWHERE in the block, we'll
- decide we can't move it, regardless of whether it changed above
- or below the store. This could be improved by checking the register
- operands while lookinng for aliasing in each insn. */
- if (!store_ops_ok (XEXP (x, 0), bb))
- return 1;
-
- for ( ; insn && insn != PREV_INSN (first); insn = PREV_INSN (insn))
- if (store_killed_in_insn (x, insn))
- return 1;
+ for ( ; insn != PREV_INSN (first); insn = PREV_INSN (insn))
+ if (store_killed_in_insn (x, x_regs, insn, true))
+ return true;
- return 0;
+ return false;
}
-#define ANTIC_STORE_LIST(x) ((x)->loads)
-#define AVAIL_STORE_LIST(x) ((x)->stores)
-
-/* Given the table of available store insns at the end of blocks,
- determine which ones are not killed by aliasing, and generate
- the appropriate vectors for gen and killed. */
+/* Fill in available, anticipatable, transparent and kill vectors in
+ STORE_DATA, based on lists of available and anticipatable stores. */
static void
-build_store_vectors ()
+build_store_vectors (void)
{
- basic_block bb, b;
+ basic_block bb;
+ int *regs_set_in_block;
rtx insn, st;
struct ls_expr * ptr;
+ unsigned regno;
/* Build the gen_vector. This is any store in the table which is not killed
by aliasing later in its block. */
- ae_gen = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores);
+ ae_gen = sbitmap_vector_alloc (last_basic_block, num_stores);
sbitmap_vector_zero (ae_gen, last_basic_block);
- st_antloc = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores);
+ st_antloc = sbitmap_vector_alloc (last_basic_block, num_stores);
sbitmap_vector_zero (st_antloc, last_basic_block);
for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr))
{
- /* Put all the stores into either the antic list, or the avail list,
- or both. */
- rtx store_list = ptr->stores;
- ptr->stores = NULL_RTX;
-
- for (st = store_list; st != NULL; st = XEXP (st, 1))
+ for (st = AVAIL_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1))
{
insn = XEXP (st, 0);
bb = BLOCK_FOR_INSN (insn);
- if (!store_killed_after (ptr->pattern, insn, bb))
+ /* If we've already seen an available expression in this block,
+ we can delete this one (It occurs earlier in the block). We'll
+ copy the SRC expression to an unused register in case there
+ are any side effects. */
+ if (TEST_BIT (ae_gen[bb->index], ptr->index))
{
- /* If we've already seen an availale expression in this block,
- we can delete the one we saw already (It occurs earlier in
- the block), and replace it with this one). We'll copy the
- old SRC expression to an unused register in case there
- are any side effects. */
- if (TEST_BIT (ae_gen[bb->index], ptr->index))
- {
- /* Find previous store. */
- rtx st;
- for (st = AVAIL_STORE_LIST (ptr); st ; st = XEXP (st, 1))
- if (BLOCK_FOR_INSN (XEXP (st, 0)) == bb)
- break;
- if (st)
- {
- rtx r = gen_reg_rtx (GET_MODE (ptr->pattern));
- if (gcse_file)
- fprintf (gcse_file, "Removing redundant store:\n");
- replace_store_insn (r, XEXP (st, 0), bb);
- XEXP (st, 0) = insn;
- continue;
- }
- }
- SET_BIT (ae_gen[bb->index], ptr->index);
- AVAIL_STORE_LIST (ptr) = alloc_INSN_LIST (insn,
- AVAIL_STORE_LIST (ptr));
- }
-
- if (!store_killed_before (ptr->pattern, insn, bb))
- {
- SET_BIT (st_antloc[BLOCK_NUM (insn)], ptr->index);
- ANTIC_STORE_LIST (ptr) = alloc_INSN_LIST (insn,
- ANTIC_STORE_LIST (ptr));
+ rtx r = gen_reg_rtx (GET_MODE (ptr->pattern));
+ if (gcse_file)
+ fprintf (gcse_file, "Removing redundant store:\n");
+ replace_store_insn (r, XEXP (st, 0), bb, ptr);
+ continue;
}
+ SET_BIT (ae_gen[bb->index], ptr->index);
}
- /* Free the original list of store insns. */
- free_INSN_LIST_list (&store_list);
+ for (st = ANTIC_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1))
+ {
+ insn = XEXP (st, 0);
+ bb = BLOCK_FOR_INSN (insn);
+ SET_BIT (st_antloc[bb->index], ptr->index);
+ }
}
- ae_kill = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores);
+ ae_kill = sbitmap_vector_alloc (last_basic_block, num_stores);
sbitmap_vector_zero (ae_kill, last_basic_block);
- transp = (sbitmap *) sbitmap_vector_alloc (last_basic_block, num_stores);
+ transp = sbitmap_vector_alloc (last_basic_block, num_stores);
sbitmap_vector_zero (transp, last_basic_block);
+ regs_set_in_block = xmalloc (sizeof (int) * max_gcse_regno);
- for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr))
- FOR_EACH_BB (b)
- {
- if (store_killed_after (ptr->pattern, b->head, b))
- {
- /* The anticipatable expression is not killed if it's gen'd. */
- /*
- We leave this check out for now. If we have a code sequence
- in a block which looks like:
- ST MEMa = x
- L y = MEMa
- ST MEMa = z
- We should flag this as having an ANTIC expression, NOT
- transparent, NOT killed, and AVAIL.
- Unfortunately, since we haven't re-written all loads to
- use the reaching reg, we'll end up doing an incorrect
- Load in the middle here if we push the store down. It happens in
- gcc.c-torture/execute/960311-1.c with -O3
- If we always kill it in this case, we'll sometimes do
- uneccessary work, but it shouldn't actually hurt anything.
- if (!TEST_BIT (ae_gen[b], ptr->index)). */
- SET_BIT (ae_kill[b->index], ptr->index);
- }
- else
- SET_BIT (transp[b->index], ptr->index);
- }
+ FOR_EACH_BB (bb)
+ {
+ for (regno = 0; regno < max_gcse_regno; regno++)
+ regs_set_in_block[regno] = TEST_BIT (reg_set_in_block[bb->index], regno);
+
+ for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr))
+ {
+ if (store_killed_after (ptr->pattern, ptr->pattern_regs, BB_HEAD (bb),
+ bb, regs_set_in_block, NULL))
+ {
+ /* It should not be necessary to consider the expression
+ killed if it is both anticipatable and available. */
+ if (!TEST_BIT (st_antloc[bb->index], ptr->index)
+ || !TEST_BIT (ae_gen[bb->index], ptr->index))
+ SET_BIT (ae_kill[bb->index], ptr->index);
+ }
+ else
+ SET_BIT (transp[bb->index], ptr->index);
+ }
+ }
+
+ free (regs_set_in_block);
- /* Any block with no exits calls some non-returning function, so
- we better mark the store killed here, or we might not store to
- it at all. If we knew it was abort, we wouldn't have to store,
- but we don't know that for sure. */
if (gcse_file)
{
- fprintf (gcse_file, "ST_avail and ST_antic (shown under loads..)\n");
- print_ldst_list (gcse_file);
dump_sbitmap_vector (gcse_file, "st_antloc", "", st_antloc, last_basic_block);
dump_sbitmap_vector (gcse_file, "st_kill", "", ae_kill, last_basic_block);
dump_sbitmap_vector (gcse_file, "Transpt", "", transp, last_basic_block);
}
}
-/* Insert an instruction at the begining of a basic block, and update
- the BLOCK_HEAD if needed. */
+/* Insert an instruction at the beginning of a basic block, and update
+ the BB_HEAD if needed. */
static void
-insert_insn_start_bb (insn, bb)
- rtx insn;
- basic_block bb;
+insert_insn_start_bb (rtx insn, basic_block bb)
{
/* Insert at start of successor block. */
- rtx prev = PREV_INSN (bb->head);
- rtx before = bb->head;
+ rtx prev = PREV_INSN (BB_HEAD (bb));
+ rtx before = BB_HEAD (bb);
while (before != 0)
{
if (GET_CODE (before) != CODE_LABEL
|| NOTE_LINE_NUMBER (before) != NOTE_INSN_BASIC_BLOCK))
break;
prev = before;
- if (prev == bb->end)
+ if (prev == BB_END (bb))
break;
before = NEXT_INSN (before);
}
}
/* This routine will insert a store on an edge. EXPR is the ldst entry for
- the memory reference, and E is the edge to insert it on. Returns non-zero
+ the memory reference, and E is the edge to insert it on. Returns nonzero
if an edge insertion was performed. */
static int
-insert_store (expr, e)
- struct ls_expr * expr;
- edge e;
+insert_store (struct ls_expr * expr, edge e)
{
rtx reg, insn;
basic_block bb;
if (expr->reaching_reg == NULL_RTX)
return 0;
+ if (e->flags & EDGE_FAKE)
+ return 0;
+
reg = expr->reaching_reg;
- insn = gen_move_insn (expr->pattern, reg);
+ insn = gen_move_insn (copy_rtx (expr->pattern), reg);
/* If we are inserting this expression on ALL predecessor edges of a BB,
insert it at the start of the BB, and reset the insert bits on the other
edges so we don't try to insert it on the other edges. */
bb = e->dest;
for (tmp = e->dest->pred; tmp ; tmp = tmp->pred_next)
- {
- int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest);
- if (index == EDGE_INDEX_NO_EDGE)
- abort ();
- if (! TEST_BIT (pre_insert_map[index], expr->index))
- break;
- }
+ if (!(tmp->flags & EDGE_FAKE))
+ {
+ int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest);
+ if (index == EDGE_INDEX_NO_EDGE)
+ abort ();
+ if (! TEST_BIT (pre_insert_map[index], expr->index))
+ break;
+ }
/* If tmp is NULL, we found an insertion on every edge, blank the
insertion vector for these edges, and insert at the start of the BB. */
return 1;
}
+/* Remove any REG_EQUAL or REG_EQUIV notes containing a reference to the
+ memory location in SMEXPR set in basic block BB.
+
+ This could be rather expensive. */
+
+static void
+remove_reachable_equiv_notes (basic_block bb, struct ls_expr *smexpr)
+{
+ edge *stack = xmalloc (sizeof (edge) * n_basic_blocks), act;
+ sbitmap visited = sbitmap_alloc (last_basic_block);
+ int stack_top = 0;
+ rtx last, insn, note;
+ rtx mem = smexpr->pattern;
+
+ sbitmap_zero (visited);
+ act = bb->succ;
+
+ while (1)
+ {
+ if (!act)
+ {
+ if (!stack_top)
+ {
+ free (stack);
+ sbitmap_free (visited);
+ return;
+ }
+ act = stack[--stack_top];
+ }
+ bb = act->dest;
+
+ if (bb == EXIT_BLOCK_PTR
+ || TEST_BIT (visited, bb->index)
+ || TEST_BIT (ae_kill[bb->index], smexpr->index))
+ {
+ act = act->succ_next;
+ continue;
+ }
+ SET_BIT (visited, bb->index);
+
+ if (TEST_BIT (st_antloc[bb->index], smexpr->index))
+ {
+ for (last = ANTIC_STORE_LIST (smexpr);
+ BLOCK_FOR_INSN (XEXP (last, 0)) != bb;
+ last = XEXP (last, 1))
+ continue;
+ last = XEXP (last, 0);
+ }
+ else
+ last = NEXT_INSN (BB_END (bb));
+
+ for (insn = BB_HEAD (bb); insn != last; insn = NEXT_INSN (insn))
+ if (INSN_P (insn))
+ {
+ note = find_reg_equal_equiv_note (insn);
+ if (!note || !expr_equiv_p (XEXP (note, 0), mem))
+ continue;
+
+ if (gcse_file)
+ fprintf (gcse_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n",
+ INSN_UID (insn));
+ remove_note (insn, note);
+ }
+ act = act->succ_next;
+ if (bb->succ)
+ {
+ if (act)
+ stack[stack_top++] = act;
+ act = bb->succ;
+ }
+ }
+}
+
/* This routine will replace a store with a SET to a specified register. */
static void
-replace_store_insn (reg, del, bb)
- rtx reg, del;
- basic_block bb;
+replace_store_insn (rtx reg, rtx del, basic_block bb, struct ls_expr *smexpr)
{
- rtx insn;
+ rtx insn, mem, note, set, ptr;
- insn = gen_move_insn (reg, SET_SRC (PATTERN (del)));
+ mem = smexpr->pattern;
+ insn = gen_move_insn (reg, SET_SRC (single_set (del)));
insn = emit_insn_after (insn, del);
if (gcse_file)
fprintf (gcse_file, "\n");
}
+ for (ptr = ANTIC_STORE_LIST (smexpr); ptr; ptr = XEXP (ptr, 1))
+ if (XEXP (ptr, 0) == del)
+ {
+ XEXP (ptr, 0) = insn;
+ break;
+ }
delete_insn (del);
+
+ /* Now we must handle REG_EQUAL notes whose contents is equal to the mem;
+ they are no longer accurate provided that they are reached by this
+ definition, so drop them. */
+ for (; insn != NEXT_INSN (BB_END (bb)); insn = NEXT_INSN (insn))
+ if (INSN_P (insn))
+ {
+ set = single_set (insn);
+ if (!set)
+ continue;
+ if (expr_equiv_p (SET_DEST (set), mem))
+ return;
+ note = find_reg_equal_equiv_note (insn);
+ if (!note || !expr_equiv_p (XEXP (note, 0), mem))
+ continue;
+
+ if (gcse_file)
+ fprintf (gcse_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n",
+ INSN_UID (insn));
+ remove_note (insn, note);
+ }
+ remove_reachable_equiv_notes (bb, smexpr);
}
the reaching_reg for later storing. */
static void
-delete_store (expr, bb)
- struct ls_expr * expr;
- basic_block bb;
+delete_store (struct ls_expr * expr, basic_block bb)
{
rtx reg, i, del;
if (expr->reaching_reg == NULL_RTX)
expr->reaching_reg = gen_reg_rtx (GET_MODE (expr->pattern));
-
- /* If there is more than 1 store, the earlier ones will be dead,
- but it doesn't hurt to replace them here. */
reg = expr->reaching_reg;
for (i = AVAIL_STORE_LIST (expr); i; i = XEXP (i, 1))
{
/* We know there is only one since we deleted redundant
ones during the available computation. */
- replace_store_insn (reg, del, bb);
+ replace_store_insn (reg, del, bb, expr);
break;
}
}
/* Free memory used by store motion. */
static void
-free_store_memory ()
+free_store_memory (void)
{
free_ldst_mems ();
other way by looking at the flowgraph in reverse. */
static void
-store_motion ()
+store_motion (void)
{
basic_block bb;
int x;
print_rtl (gcse_file, get_insns ());
}
-
init_alias_analysis ();
- /* Find all the stores that are live to the end of their block. */
+ /* Find all the available and anticipatable stores. */
num_stores = compute_store_table ();
if (num_stores == 0)
{
return;
}
- /* Now compute whats actually available to move. */
- add_noreturn_fake_exit_edges ();
+ /* Now compute kill & transp vectors. */
build_store_vectors ();
+ add_noreturn_fake_exit_edges ();
+ connect_infinite_loops_to_exit ();
edge_list = pre_edge_rev_lcm (gcse_file, num_stores, transp, ae_gen,
st_antloc, ae_kill, &pre_insert_map,
end_alias_analysis ();
}
+\f
+/* Entry point for jump bypassing optimization pass. */
+
+int
+bypass_jumps (FILE *file)
+{
+ int changed;
+
+ /* We do not construct an accurate cfg in functions which call
+ setjmp, so just punt to be safe. */
+ if (current_function_calls_setjmp)
+ return 0;
+
+ /* For calling dump_foo fns from gdb. */
+ debug_stderr = stderr;
+ gcse_file = file;
+
+ /* Identify the basic block information for this function, including
+ successors and predecessors. */
+ max_gcse_regno = max_reg_num ();
+
+ if (file)
+ dump_flow_info (file);
+
+ /* Return if there's nothing to do, or it is too expensive. */
+ if (n_basic_blocks <= 1 || is_too_expensive (_ ("jump bypassing disabled")))
+ return 0;
+
+ gcc_obstack_init (&gcse_obstack);
+ bytes_used = 0;
+
+ /* We need alias. */
+ init_alias_analysis ();
+
+ /* Record where pseudo-registers are set. This data is kept accurate
+ during each pass. ??? We could also record hard-reg information here
+ [since it's unchanging], however it is currently done during hash table
+ computation.
+
+ It may be tempting to compute MEM set information here too, but MEM sets
+ will be subject to code motion one day and thus we need to compute
+ information about memory sets when we build the hash tables. */
+
+ alloc_reg_set_mem (max_gcse_regno);
+ compute_sets (get_insns ());
+
+ max_gcse_regno = max_reg_num ();
+ alloc_gcse_mem (get_insns ());
+ changed = one_cprop_pass (1, 1, 1);
+ free_gcse_mem ();
+
+ if (file)
+ {
+ fprintf (file, "BYPASS of %s: %d basic blocks, ",
+ current_function_name (), n_basic_blocks);
+ fprintf (file, "%d bytes\n\n", bytes_used);
+ }
+
+ obstack_free (&gcse_obstack, NULL);
+ free_reg_set_mem ();
+
+ /* We are finished with alias. */
+ end_alias_analysis ();
+ allocate_reg_info (max_reg_num (), FALSE, FALSE);
+
+ return changed;
+}
+
+/* Return true if the graph is too expensive to optimize. PASS is the
+ optimization about to be performed. */
+
+static bool
+is_too_expensive (const char *pass)
+{
+ /* Trying to perform global optimizations on flow graphs which have
+ a high connectivity will take a long time and is unlikely to be
+ particularly useful.
+
+ In normal circumstances a cfg should have about twice as many
+ edges as blocks. But we do not want to punish small functions
+ which have a couple switch statements. Rather than simply
+ threshold the number of blocks, uses something with a more
+ graceful degradation. */
+ if (n_edges > 20000 + n_basic_blocks * 4)
+ {
+ if (warn_disabled_optimization)
+ warning ("%s: %d basic blocks and %d edges/basic block",
+ pass, n_basic_blocks, n_edges / n_basic_blocks);
+
+ return true;
+ }
+
+ /* If allocating memory for the cprop bitmap would take up too much
+ storage it's better just to disable the optimization. */
+ if ((n_basic_blocks
+ * SBITMAP_SET_SIZE (max_reg_num ())
+ * sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY)
+ {
+ if (warn_disabled_optimization)
+ warning ("%s: %d basic blocks and %d registers",
+ pass, n_basic_blocks, max_reg_num ());
+
+ return true;
+ }
+
+ return false;
+}
+
#include "gt-gcse.h"
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