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author | steven <steven@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-04-30 10:51:08 +0000 |
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committer | steven <steven@138bc75d-0d04-0410-961f-82ee72b054a4> | 2009-04-30 10:51:08 +0000 |
commit | 4b673aa1dde655e1d89d31e583168d5831f32819 (patch) | |
tree | 5267d15c4c34801fce266c5a6afb6cea477323ea /gcc/gcse.c | |
parent | aca3a78faf88f12a2de44b00e129c1f015548c90 (diff) | |
download | gcc-4b673aa1dde655e1d89d31e583168d5831f32819.tar.gz |
* gcse.c (ae_gen): Remove.
(can_assign_to_reg_p): Rename to can_assign_to_reg_without_clobbers_p
and make non-static function to make it available in store-motion.c.
Update call sites with search-and-replace.
(enumerate_ldsts, reg_set_info, reg_clear_last_set, store_ops_ok,
extract_mentioned_regs, extract_mentioned_regs_helper,
find_moveable_store, compute_store_table, load_kills_store, find_loads,
store_killed_in_insn, store_killed_after, store_killed_before,
build_store_vectors, insert_insn_start_basic_block, insert-store,
remove_reachable_equiv_notes, replace_store_insn, delete_store,
free_store_memory, one_store_motion_pass, gate_rtl_store_motion,
execute_rtl_store_motion, pass_rtl_store_motion): Move to...
* store-motion.c: ...new file. Also copy data structures from gcse.c
and clean up to remove parts not used by store motion.
* rtl.h (can_assign_to_reg_without_clobbers_p): Add prototype.
* Makefile.in (store-motion.o): New rule. Add to OBJS-common.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@147001 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/gcse.c')
-rw-r--r-- | gcc/gcse.c | 1178 |
1 files changed, 12 insertions, 1166 deletions
diff --git a/gcc/gcse.c b/gcc/gcse.c index ab3137eae02..b3fa362aff3 100644 --- a/gcc/gcse.c +++ b/gcc/gcse.c @@ -437,7 +437,7 @@ static int global_const_prop_count; static int global_copy_prop_count; /* For available exprs */ -static sbitmap *ae_kill, *ae_gen; +static sbitmap *ae_kill; static void compute_can_copy (void); static void *gmalloc (size_t) ATTRIBUTE_MALLOC; @@ -450,7 +450,6 @@ 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 can_assign_to_reg_p (rtx); static bool gcse_constant_p (const_rtx); static int oprs_unchanged_p (const_rtx, const_rtx, int); static int oprs_anticipatable_p (const_rtx, const_rtx); @@ -527,7 +526,6 @@ 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 (const_rtx); @@ -535,26 +533,6 @@ 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, const_rtx, void *); -static void reg_clear_last_set (rtx, const_rtx, void *); -static bool store_ops_ok (const_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 (const_rtx, const_rtx, int); -static bool find_loads (const_rtx, const_rtx, int); -static bool store_killed_in_insn (const_rtx, const_rtx, const_rtx, int); -static bool store_killed_after (const_rtx, const_rtx, const_rtx, const_basic_block, int *, rtx *); -static bool store_killed_before (const_rtx, const_rtx, const_rtx, const_basic_block, int *); -static void build_store_vectors (void); -static void insert_insn_start_basic_block (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 int one_store_motion_pass (void); static void free_insn_expr_list_list (rtx *); static void clear_modify_mem_tables (void); static void free_modify_mem_tables (void); @@ -816,18 +794,23 @@ want_to_gcse_p (rtx x) return 0; default: - return can_assign_to_reg_p (x); + return can_assign_to_reg_without_clobbers_p (x); } } -/* Used internally by can_assign_to_reg_p. */ +/* Used internally by can_assign_to_reg_without_clobbers_p. */ static GTY(()) rtx test_insn; -/* Return true if we can assign X to a pseudo register. */ +/* Return true if we can assign X to a pseudo register such that the + resulting insn does not result in clobbering a hard register as a + side-effect. + This function is typically used by code motion passes, to verify + that it is safe to insert an insn without worrying about clobbering + maybe live hard regs. */ -static bool -can_assign_to_reg_p (rtx x) +bool +can_assign_to_reg_without_clobbers_p (rtx x) { int num_clobbers = 0; int icode; @@ -4642,20 +4625,6 @@ find_rtx_in_ldst (rtx x) return (struct ls_expr *) *slot; } -/* Assign each element of the list of mems a monotonically increasing value. */ - -static int -enumerate_ldsts (void) -{ - struct ls_expr * ptr; - int n = 0; - - for (ptr = pre_ldst_mems; ptr != NULL; ptr = ptr->next) - ptr->index = n++; - - return n; -} - /* Return first item in the list. */ static inline struct ls_expr * @@ -4801,7 +4770,7 @@ compute_ld_motion_mems (void) && GET_CODE (src) != ASM_OPERANDS /* Check for REG manually since want_to_gcse_p returns 0 for all REGs. */ - && can_assign_to_reg_p (src)) + && can_assign_to_reg_without_clobbers_p (src)) ptr->stores = alloc_INSN_LIST (insn, ptr->stores); else ptr->invalid = 1; @@ -4920,1089 +4889,6 @@ update_ld_motion_stores (struct expr * expr) } } -/* 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 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. */ - -static void -reg_set_info (rtx dest, const_rtx setter ATTRIBUTE_UNUSED, - void *data ATTRIBUTE_UNUSED) -{ - if (GET_CODE (dest) == SUBREG) - dest = SUBREG_REG (dest); - - if (REG_P (dest)) - regvec[REGNO (dest)] = INSN_UID (compute_store_table_current_insn); -} - -/* Clear any mark that says that this insn sets dest. Called from - note_stores. */ - -static void -reg_clear_last_set (rtx dest, const_rtx setter ATTRIBUTE_UNUSED, - void *data) -{ - int *dead_vec = (int *) data; - - if (GET_CODE (dest) == SUBREG) - dest = SUBREG_REG (dest); - - if (REG_P (dest) && - 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 (const_rtx x, int *regs_set) -{ - const_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; - const char * fmt; - - /* Repeat is used to turn tail-recursion into iteration. */ - repeat: - - if (x == 0) - return accum; - - code = GET_CODE (x); - switch (code) - { - case REG: - return alloc_EXPR_LIST (0, x, accum); - - case MEM: - x = XEXP (x, 0); - goto repeat; - - case PRE_DEC: - case PRE_INC: - case PRE_MODIFY: - case POST_DEC: - case POST_INC: - case POST_MODIFY: - /* We do not run this function with arguments having side effects. */ - gcc_unreachable (); - - case PC: - case CC0: /*FIXME*/ - case CONST: - case CONST_INT: - case CONST_DOUBLE: - case CONST_FIXED: - case CONST_VECTOR: - case SYMBOL_REF: - case LABEL_REF: - case ADDR_VEC: - case ADDR_DIFF_VEC: - return accum; - - default: - break; - } - - i = GET_RTX_LENGTH (code) - 1; - fmt = GET_RTX_FORMAT (code); - - for (; i >= 0; i--) - { - if (fmt[i] == 'e') - { - rtx tem = XEXP (x, i); - - /* If we are about to do the last recursive call - needed at this level, change it into iteration. */ - if (i == 0) - { - x = tem; - goto repeat; - } - - accum = extract_mentioned_regs_helper (tem, accum); - } - else if (fmt[i] == 'E') - { - int j; - - for (j = 0; j < XVECLEN (x, i); j++) - accum = extract_mentioned_regs_helper (XVECEXP (x, i, j), accum); - } - } - - return accum; -} - -/* 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 (rtx insn, int *regs_set_before, int *regs_set_after) -{ - struct ls_expr * ptr; - rtx dest, set, tmp; - int check_anticipatable, check_available; - basic_block bb = BLOCK_FOR_INSN (insn); - - set = single_set (insn); - if (!set) - return; - - dest = SET_DEST (set); - - if (! MEM_P (dest) || MEM_VOLATILE_P (dest) - || GET_MODE (dest) == BLKmode) - return; - - if (side_effects_p (dest)) - return; - - /* 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; - - /* Even if the destination cannot trap, the source may. In this case we'd - need to handle updating the REG_EH_REGION note. */ - if (find_reg_note (insn, REG_EH_REGION, NULL_RTX)) - return; - - /* Make sure that the SET_SRC of this store insns can be assigned to - a register, or we will fail later on in replace_store_insn, which - assumes that we can do this. But sometimes the target machine has - oddities like MEM read-modify-write instruction. See for example - PR24257. */ - if (!can_assign_to_reg_p (SET_SRC (set))) - return; - - ptr = ldst_entry (dest); - 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)); -} - -/* Find available and anticipatable stores. */ - -static int -compute_store_table (void) -{ - int ret; - basic_block bb; - unsigned regno; - rtx insn, pat, tmp; - int *last_set_in, *already_set; - struct ls_expr * ptr, **prev_next_ptr_ptr; - unsigned int max_gcse_regno = max_reg_num (); - - pre_ldst_mems = 0; - pre_ldst_table = htab_create (13, pre_ldst_expr_hash, - pre_ldst_expr_eq, NULL); - last_set_in = XCNEWVEC (int, max_gcse_regno); - already_set = XNEWVEC (int, max_gcse_regno); - - /* Find all the stores we care about. */ - FOR_EACH_BB (bb) - { - /* First compute the registers set in this block. */ - regvec = last_set_in; - - FOR_BB_INSNS (bb, insn) - { - if (! INSN_P (insn)) - continue; - - if (CALL_P (insn)) - { - for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) - if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)) - last_set_in[regno] = INSN_UID (insn); - } - - pat = PATTERN (insn); - compute_store_table_current_insn = insn; - note_stores (pat, reg_set_info, NULL); - } - - /* Now find the stores. */ - memset (already_set, 0, sizeof (int) * max_gcse_regno); - regvec = already_set; - FOR_BB_INSNS (bb, insn) - { - if (! INSN_P (insn)) - continue; - - if (CALL_P (insn)) - { - for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) - if (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. */ - 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 (CALL_P (insn)) - { - for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++) - if (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++) - gcc_assert (!last_set_in[regno]); -#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; - htab_remove_elt_with_hash (pre_ldst_table, ptr, ptr->hash_index); - free_ldst_entry (ptr); - } - else - prev_next_ptr_ptr = &ptr->next; - } - - ret = enumerate_ldsts (); - - if (dump_file) - { - fprintf (dump_file, "ST_avail and ST_antic (shown under loads..)\n"); - print_ldst_list (dump_file); - } - - free (last_set_in); - free (already_set); - return ret; -} - -/* 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 bool -load_kills_store (const_rtx x, const_rtx store_pattern, int after) -{ - 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 true if found. - AFTER is true if we are checking the case when STORE_PATTERN occurs - after the insn X. */ - -static bool -find_loads (const_rtx x, const_rtx store_pattern, int after) -{ - const char * fmt; - int i, j; - int ret = false; - - if (!x) - return false; - - if (GET_CODE (x) == SET) - x = SET_SRC (x); - - if (MEM_P (x)) - { - if (load_kills_store (x, store_pattern, after)) - return true; - } - - /* Recursively process the insn. */ - fmt = GET_RTX_FORMAT (GET_CODE (x)); - - 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, after); - else if (fmt[i] == 'E') - for (j = XVECLEN (x, i) - 1; j >= 0; j--) - ret |= find_loads (XVECEXP (x, i, j), store_pattern, after); - } - return ret; -} - -static inline bool -store_killed_in_pat (const_rtx x, const_rtx pat, int after) -{ - if (GET_CODE (pat) == SET) - { - rtx dest = SET_DEST (pat); - - if (GET_CODE (dest) == ZERO_EXTRACT) - dest = XEXP (dest, 0); - - /* Check for memory stores to aliased objects. */ - if (MEM_P (dest) - && !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 (pat, x, after)) - return true; - - return false; -} - -/* Check if INSN kills the store pattern X (is aliased with it). - AFTER is true if we are checking the case when store X occurs - after the insn. Return true if it does. */ - -static bool -store_killed_in_insn (const_rtx x, const_rtx x_regs, const_rtx insn, int after) -{ - const_rtx reg, base, note, pat; - - if (!INSN_P (insn)) - return false; - - if (CALL_P (insn)) - { - /* A normal or pure call might read from pattern, - but a const call will not. */ - if (!RTL_CONST_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; - } - - pat = PATTERN (insn); - if (GET_CODE (pat) == SET) - { - if (store_killed_in_pat (x, pat, after)) - return true; - } - else if (GET_CODE (pat) == PARALLEL) - { - int i; - - for (i = 0; i < XVECLEN (pat, 0); i++) - if (store_killed_in_pat (x, XVECEXP (pat, 0, i), after)) - return true; - } - 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 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 bool -store_killed_after (const_rtx x, const_rtx x_regs, const_rtx insn, const_basic_block bb, - int *regs_set_after, rtx *fail_insn) -{ - rtx last = BB_END (bb), act; - - 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; - } - - /* 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 false; -} - -/* 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 (const_rtx x, const_rtx x_regs, const_rtx insn, const_basic_block bb, - int *regs_set_before) -{ - rtx first = BB_HEAD (bb); - - if (!store_ops_ok (x_regs, regs_set_before)) - return true; - - for ( ; insn != PREV_INSN (first); insn = PREV_INSN (insn)) - if (store_killed_in_insn (x, x_regs, insn, true)) - return true; - - return false; -} - -/* Fill in available, anticipatable, transparent and kill vectors in - STORE_DATA, based on lists of available and anticipatable stores. */ -static void -build_store_vectors (void) -{ - basic_block bb; - int *regs_set_in_block; - rtx insn, st; - struct ls_expr * ptr; - unsigned int max_gcse_regno = max_reg_num (); - - /* Build the gen_vector. This is any store in the table which is not killed - by aliasing later in its block. */ - ae_gen = sbitmap_vector_alloc (last_basic_block, num_stores); - sbitmap_vector_zero (ae_gen, last_basic_block); - - 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)) - { - for (st = AVAIL_STORE_LIST (ptr); st != NULL; st = XEXP (st, 1)) - { - insn = XEXP (st, 0); - bb = BLOCK_FOR_INSN (insn); - - /* 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)) - { - rtx r = gen_reg_rtx_and_attrs (ptr->pattern); - if (dump_file) - fprintf (dump_file, "Removing redundant store:\n"); - replace_store_insn (r, XEXP (st, 0), bb, ptr); - continue; - } - SET_BIT (ae_gen[bb->index], ptr->index); - } - - 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_vector_alloc (last_basic_block, num_stores); - sbitmap_vector_zero (ae_kill, last_basic_block); - - transp = sbitmap_vector_alloc (last_basic_block, num_stores); - sbitmap_vector_zero (transp, last_basic_block); - regs_set_in_block = XNEWVEC (int, max_gcse_regno); - - FOR_EACH_BB (bb) - { - FOR_BB_INSNS (bb, insn) - if (INSN_P (insn)) - { - df_ref *def_rec; - for (def_rec = DF_INSN_DEFS (insn); *def_rec; def_rec++) - { - unsigned int ref_regno = DF_REF_REGNO (*def_rec); - if (ref_regno < max_gcse_regno) - regs_set_in_block[DF_REF_REGNO (*def_rec)] = 1; - } - } - - 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); - - if (dump_file) - { - dump_sbitmap_vector (dump_file, "st_antloc", "", st_antloc, last_basic_block); - dump_sbitmap_vector (dump_file, "st_kill", "", ae_kill, last_basic_block); - dump_sbitmap_vector (dump_file, "Transpt", "", transp, last_basic_block); - dump_sbitmap_vector (dump_file, "st_avloc", "", ae_gen, last_basic_block); - } -} - -/* Insert an instruction at the beginning of a basic block, and update - the BB_HEAD if needed. */ - -static void -insert_insn_start_basic_block (rtx insn, basic_block bb) -{ - /* Insert at start of successor block. */ - rtx prev = PREV_INSN (BB_HEAD (bb)); - rtx before = BB_HEAD (bb); - while (before != 0) - { - if (! LABEL_P (before) - && !NOTE_INSN_BASIC_BLOCK_P (before)) - break; - prev = before; - if (prev == BB_END (bb)) - break; - before = NEXT_INSN (before); - } - - insn = emit_insn_after_noloc (insn, prev, bb); - - if (dump_file) - { - fprintf (dump_file, "STORE_MOTION insert store at start of BB %d:\n", - bb->index); - print_inline_rtx (dump_file, insn, 6); - fprintf (dump_file, "\n"); - } -} - -/* 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 nonzero - if an edge insertion was performed. */ - -static int -insert_store (struct ls_expr * expr, edge e) -{ - rtx reg, insn; - basic_block bb; - edge tmp; - edge_iterator ei; - - /* We did all the deleted before this insert, so if we didn't delete a - store, then we haven't set the reaching reg yet either. */ - if (expr->reaching_reg == NULL_RTX) - return 0; - - if (e->flags & EDGE_FAKE) - return 0; - - reg = expr->reaching_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_EACH_EDGE (tmp, ei, e->dest->preds) - if (!(tmp->flags & EDGE_FAKE)) - { - int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); - - gcc_assert (index != EDGE_INDEX_NO_EDGE); - 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. */ - if (!tmp && bb != EXIT_BLOCK_PTR) - { - FOR_EACH_EDGE (tmp, ei, e->dest->preds) - { - int index = EDGE_INDEX (edge_list, tmp->src, tmp->dest); - RESET_BIT (pre_insert_map[index], expr->index); - } - insert_insn_start_basic_block (insn, bb); - return 0; - } - - /* We can't put stores in the front of blocks pointed to by abnormal - edges since that may put a store where one didn't used to be. */ - gcc_assert (!(e->flags & EDGE_ABNORMAL)); - - insert_insn_on_edge (insn, e); - - if (dump_file) - { - fprintf (dump_file, "STORE_MOTION insert insn on edge (%d, %d):\n", - e->src->index, e->dest->index); - print_inline_rtx (dump_file, insn, 6); - fprintf (dump_file, "\n"); - } - - 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_iterator *stack, ei; - int sp; - edge act; - sbitmap visited = sbitmap_alloc (last_basic_block); - rtx last, insn, note; - rtx mem = smexpr->pattern; - - stack = XNEWVEC (edge_iterator, n_basic_blocks); - sp = 0; - ei = ei_start (bb->succs); - - sbitmap_zero (visited); - - act = (EDGE_COUNT (ei_container (ei)) > 0 ? EDGE_I (ei_container (ei), 0) : NULL); - while (1) - { - if (!act) - { - if (!sp) - { - free (stack); - sbitmap_free (visited); - return; - } - act = ei_edge (stack[--sp]); - } - bb = act->dest; - - if (bb == EXIT_BLOCK_PTR - || TEST_BIT (visited, bb->index)) - { - if (!ei_end_p (ei)) - ei_next (&ei); - act = (! ei_end_p (ei)) ? ei_edge (ei) : NULL; - 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 (dump_file) - fprintf (dump_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n", - INSN_UID (insn)); - remove_note (insn, note); - } - - if (!ei_end_p (ei)) - ei_next (&ei); - act = (! ei_end_p (ei)) ? ei_edge (ei) : NULL; - - if (EDGE_COUNT (bb->succs) > 0) - { - if (act) - stack[sp++] = ei; - ei = ei_start (bb->succs); - act = (EDGE_COUNT (ei_container (ei)) > 0 ? EDGE_I (ei_container (ei), 0) : NULL); - } - } -} - -/* This routine will replace a store with a SET to a specified register. */ - -static void -replace_store_insn (rtx reg, rtx del, basic_block bb, struct ls_expr *smexpr) -{ - rtx insn, mem, note, set, ptr; - - mem = smexpr->pattern; - insn = gen_move_insn (reg, SET_SRC (single_set (del))); - - for (ptr = ANTIC_STORE_LIST (smexpr); ptr; ptr = XEXP (ptr, 1)) - if (XEXP (ptr, 0) == del) - { - XEXP (ptr, 0) = insn; - break; - } - - /* Move the notes from the deleted insn to its replacement. */ - REG_NOTES (insn) = REG_NOTES (del); - - /* Emit the insn AFTER all the notes are transferred. - This is cheaper since we avoid df rescanning for the note change. */ - insn = emit_insn_after (insn, del); - - if (dump_file) - { - fprintf (dump_file, - "STORE_MOTION delete insn in BB %d:\n ", bb->index); - print_inline_rtx (dump_file, del, 6); - fprintf (dump_file, "\nSTORE_MOTION replaced with insn:\n "); - print_inline_rtx (dump_file, insn, 6); - fprintf (dump_file, "\n"); - } - - 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 (dump_file) - fprintf (dump_file, "STORE_MOTION drop REG_EQUAL note at insn %d:\n", - INSN_UID (insn)); - remove_note (insn, note); - } - remove_reachable_equiv_notes (bb, smexpr); -} - - -/* Delete a store, but copy the value that would have been stored into - the reaching_reg for later storing. */ - -static void -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_and_attrs (expr->pattern); - - reg = expr->reaching_reg; - - for (i = AVAIL_STORE_LIST (expr); i; i = XEXP (i, 1)) - { - del = XEXP (i, 0); - if (BLOCK_FOR_INSN (del) == bb) - { - /* We know there is only one since we deleted redundant - ones during the available computation. */ - replace_store_insn (reg, del, bb, expr); - break; - } - } -} - -/* Free memory used by store motion. */ - -static void -free_store_memory (void) -{ - free_ldst_mems (); - - if (ae_gen) - sbitmap_vector_free (ae_gen); - if (ae_kill) - sbitmap_vector_free (ae_kill); - if (transp) - sbitmap_vector_free (transp); - if (st_antloc) - sbitmap_vector_free (st_antloc); - if (pre_insert_map) - sbitmap_vector_free (pre_insert_map); - if (pre_delete_map) - sbitmap_vector_free (pre_delete_map); - - ae_gen = ae_kill = transp = st_antloc = NULL; - pre_insert_map = pre_delete_map = NULL; -} - -/* Perform store motion. Much like gcse, except we move expressions the - other way by looking at the flowgraph in reverse. - Return non-zero if transformations are performed by the pass. */ - -static int -one_store_motion_pass (void) -{ - basic_block bb; - int x; - struct ls_expr * ptr; - int update_flow = 0; - - gcse_subst_count = 0; - gcse_create_count = 0; - - init_alias_analysis (); - - /* Find all the available and anticipatable stores. */ - num_stores = compute_store_table (); - if (num_stores == 0) - { - htab_delete (pre_ldst_table); - pre_ldst_table = NULL; - end_alias_analysis (); - return 0; - } - - /* Now compute kill & transp vectors. */ - build_store_vectors (); - add_noreturn_fake_exit_edges (); - connect_infinite_loops_to_exit (); - - edge_list = pre_edge_rev_lcm (num_stores, transp, ae_gen, - st_antloc, ae_kill, &pre_insert_map, - &pre_delete_map); - - /* Now we want to insert the new stores which are going to be needed. */ - for (ptr = first_ls_expr (); ptr != NULL; ptr = next_ls_expr (ptr)) - { - /* If any of the edges we have above are abnormal, we can't move this - store. */ - for (x = NUM_EDGES (edge_list) - 1; x >= 0; x--) - if (TEST_BIT (pre_insert_map[x], ptr->index) - && (INDEX_EDGE (edge_list, x)->flags & EDGE_ABNORMAL)) - break; - - if (x >= 0) - { - if (dump_file != NULL) - fprintf (dump_file, - "Can't replace store %d: abnormal edge from %d to %d\n", - ptr->index, INDEX_EDGE (edge_list, x)->src->index, - INDEX_EDGE (edge_list, x)->dest->index); - continue; - } - - /* Now we want to insert the new stores which are going to be needed. */ - - FOR_EACH_BB (bb) - if (TEST_BIT (pre_delete_map[bb->index], ptr->index)) - { - delete_store (ptr, bb); - gcse_subst_count++; - } - - for (x = 0; x < NUM_EDGES (edge_list); x++) - if (TEST_BIT (pre_insert_map[x], ptr->index)) - { - update_flow |= insert_store (ptr, INDEX_EDGE (edge_list, x)); - gcse_create_count++; - } - } - - if (update_flow) - commit_edge_insertions (); - - free_store_memory (); - free_edge_list (edge_list); - remove_fake_exit_edges (); - end_alias_analysis (); - - if (dump_file) - { - fprintf (dump_file, "STORE_MOTION of %s, %d basic blocks, ", - current_function_name (), n_basic_blocks); - fprintf (dump_file, "%d substs, %d insns created\n", - gcse_subst_count, gcse_create_count); - } - - return (gcse_subst_count > 0 || gcse_create_count > 0); -} - - /* Return true if the graph is too expensive to optimize. PASS is the optimization about to be performed. */ @@ -6214,25 +5100,6 @@ execute_rtl_hoist (void) return 0; } -static bool -gate_rtl_store_motion (void) -{ - return optimize > 0 && flag_gcse_sm - && !cfun->calls_setjmp - && optimize_function_for_speed_p (cfun) - && dbg_cnt (store_motion); -} - -static unsigned int -execute_rtl_store_motion (void) -{ - delete_unreachable_blocks (); - df_note_add_problem (); - df_analyze (); - flag_rerun_cse_after_global_opts |= one_store_motion_pass (); - return 0; -} - struct rtl_opt_pass pass_rtl_cprop = { { @@ -6296,25 +5163,4 @@ struct rtl_opt_pass pass_rtl_hoist = } }; -struct rtl_opt_pass pass_rtl_store_motion = -{ - { - RTL_PASS, - "store_motion", /* name */ - gate_rtl_store_motion, /* gate */ - execute_rtl_store_motion, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - TV_LSM, /* tv_id */ - PROP_cfglayout, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_df_finish | TODO_verify_rtl_sharing | - TODO_dump_func | - TODO_verify_flow | TODO_ggc_collect /* todo_flags_finish */ - } -}; - #include "gt-gcse.h" |