| /* Common subexpression elimination library for GNU compiler. |
| Copyright (C) 1987-2021 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "target.h" |
| #include "rtl.h" |
| #include "tree.h" |
| #include "df.h" |
| #include "memmodel.h" |
| #include "tm_p.h" |
| #include "regs.h" |
| #include "emit-rtl.h" |
| #include "dumpfile.h" |
| #include "cselib.h" |
| #include "function-abi.h" |
| |
| /* A list of cselib_val structures. */ |
| struct elt_list |
| { |
| struct elt_list *next; |
| cselib_val *elt; |
| }; |
| |
| static bool cselib_record_memory; |
| static bool cselib_preserve_constants; |
| static bool cselib_any_perm_equivs; |
| static inline void promote_debug_loc (struct elt_loc_list *l); |
| static struct elt_list *new_elt_list (struct elt_list *, cselib_val *); |
| static void new_elt_loc_list (cselib_val *, rtx); |
| static void unchain_one_value (cselib_val *); |
| static void unchain_one_elt_list (struct elt_list **); |
| static void unchain_one_elt_loc_list (struct elt_loc_list **); |
| static void remove_useless_values (void); |
| static unsigned int cselib_hash_rtx (rtx, int, machine_mode); |
| static cselib_val *new_cselib_val (unsigned int, machine_mode, rtx); |
| static void add_mem_for_addr (cselib_val *, cselib_val *, rtx); |
| static cselib_val *cselib_lookup_mem (rtx, int); |
| static void cselib_invalidate_regno (unsigned int, machine_mode); |
| static void cselib_invalidate_mem (rtx); |
| static void cselib_record_set (rtx, cselib_val *, cselib_val *); |
| static void cselib_record_sets (rtx_insn *); |
| static rtx autoinc_split (rtx, rtx *, machine_mode); |
| |
| #define PRESERVED_VALUE_P(RTX) \ |
| (RTL_FLAG_CHECK1 ("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging) |
| |
| #define SP_BASED_VALUE_P(RTX) \ |
| (RTL_FLAG_CHECK1 ("SP_BASED_VALUE_P", (RTX), VALUE)->jump) |
| |
| #define SP_DERIVED_VALUE_P(RTX) \ |
| (RTL_FLAG_CHECK1 ("SP_DERIVED_VALUE_P", (RTX), VALUE)->call) |
| |
| struct expand_value_data |
| { |
| bitmap regs_active; |
| cselib_expand_callback callback; |
| void *callback_arg; |
| bool dummy; |
| }; |
| |
| static rtx cselib_expand_value_rtx_1 (rtx, struct expand_value_data *, int); |
| |
| /* There are three ways in which cselib can look up an rtx: |
| - for a REG, the reg_values table (which is indexed by regno) is used |
| - for a MEM, we recursively look up its address and then follow the |
| addr_list of that value |
| - for everything else, we compute a hash value and go through the hash |
| table. Since different rtx's can still have the same hash value, |
| this involves walking the table entries for a given value and comparing |
| the locations of the entries with the rtx we are looking up. */ |
| |
| struct cselib_hasher : nofree_ptr_hash <cselib_val> |
| { |
| struct key { |
| /* The rtx value and its mode (needed separately for constant |
| integers). */ |
| machine_mode mode; |
| rtx x; |
| /* The mode of the contaning MEM, if any, otherwise VOIDmode. */ |
| machine_mode memmode; |
| }; |
| typedef key *compare_type; |
| static inline hashval_t hash (const cselib_val *); |
| static inline bool equal (const cselib_val *, const key *); |
| }; |
| |
| /* The hash function for our hash table. The value is always computed with |
| cselib_hash_rtx when adding an element; this function just extracts the |
| hash value from a cselib_val structure. */ |
| |
| inline hashval_t |
| cselib_hasher::hash (const cselib_val *v) |
| { |
| return v->hash; |
| } |
| |
| /* The equality test for our hash table. The first argument V is a table |
| element (i.e. a cselib_val), while the second arg X is an rtx. We know |
| that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a |
| CONST of an appropriate mode. */ |
| |
| inline bool |
| cselib_hasher::equal (const cselib_val *v, const key *x_arg) |
| { |
| struct elt_loc_list *l; |
| rtx x = x_arg->x; |
| machine_mode mode = x_arg->mode; |
| machine_mode memmode = x_arg->memmode; |
| |
| if (mode != GET_MODE (v->val_rtx)) |
| return false; |
| |
| if (GET_CODE (x) == VALUE) |
| return x == v->val_rtx; |
| |
| if (SP_DERIVED_VALUE_P (v->val_rtx) && GET_MODE (x) == Pmode) |
| { |
| rtx xoff = NULL; |
| if (autoinc_split (x, &xoff, memmode) == v->val_rtx && xoff == NULL_RTX) |
| return true; |
| } |
| |
| /* We don't guarantee that distinct rtx's have different hash values, |
| so we need to do a comparison. */ |
| for (l = v->locs; l; l = l->next) |
| if (rtx_equal_for_cselib_1 (l->loc, x, memmode, 0)) |
| { |
| promote_debug_loc (l); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* A table that enables us to look up elts by their value. */ |
| static hash_table<cselib_hasher> *cselib_hash_table; |
| |
| /* A table to hold preserved values. */ |
| static hash_table<cselib_hasher> *cselib_preserved_hash_table; |
| |
| /* This is a global so we don't have to pass this through every function. |
| It is used in new_elt_loc_list to set SETTING_INSN. */ |
| static rtx_insn *cselib_current_insn; |
| |
| /* The unique id that the next create value will take. */ |
| static unsigned int next_uid; |
| |
| /* The number of registers we had when the varrays were last resized. */ |
| static unsigned int cselib_nregs; |
| |
| /* Count values without known locations, or with only locations that |
| wouldn't have been known except for debug insns. Whenever this |
| grows too big, we remove these useless values from the table. |
| |
| Counting values with only debug values is a bit tricky. We don't |
| want to increment n_useless_values when we create a value for a |
| debug insn, for this would get n_useless_values out of sync, but we |
| want increment it if all locs in the list that were ever referenced |
| in nondebug insns are removed from the list. |
| |
| In the general case, once we do that, we'd have to stop accepting |
| nondebug expressions in the loc list, to avoid having two values |
| equivalent that, without debug insns, would have been made into |
| separate values. However, because debug insns never introduce |
| equivalences themselves (no assignments), the only means for |
| growing loc lists is through nondebug assignments. If the locs |
| also happen to be referenced in debug insns, it will work just fine. |
| |
| A consequence of this is that there's at most one debug-only loc in |
| each loc list. If we keep it in the first entry, testing whether |
| we have a debug-only loc list takes O(1). |
| |
| Furthermore, since any additional entry in a loc list containing a |
| debug loc would have to come from an assignment (nondebug) that |
| references both the initial debug loc and the newly-equivalent loc, |
| the initial debug loc would be promoted to a nondebug loc, and the |
| loc list would not contain debug locs any more. |
| |
| So the only case we have to be careful with in order to keep |
| n_useless_values in sync between debug and nondebug compilations is |
| to avoid incrementing n_useless_values when removing the single loc |
| from a value that turns out to not appear outside debug values. We |
| increment n_useless_debug_values instead, and leave such values |
| alone until, for other reasons, we garbage-collect useless |
| values. */ |
| static int n_useless_values; |
| static int n_useless_debug_values; |
| |
| /* Count values whose locs have been taken exclusively from debug |
| insns for the entire life of the value. */ |
| static int n_debug_values; |
| |
| /* Number of useless values before we remove them from the hash table. */ |
| #define MAX_USELESS_VALUES 32 |
| |
| /* This table maps from register number to values. It does not |
| contain pointers to cselib_val structures, but rather elt_lists. |
| The purpose is to be able to refer to the same register in |
| different modes. The first element of the list defines the mode in |
| which the register was set; if the mode is unknown or the value is |
| no longer valid in that mode, ELT will be NULL for the first |
| element. */ |
| static struct elt_list **reg_values; |
| static unsigned int reg_values_size; |
| #define REG_VALUES(i) reg_values[i] |
| |
| /* The largest number of hard regs used by any entry added to the |
| REG_VALUES table. Cleared on each cselib_clear_table() invocation. */ |
| static unsigned int max_value_regs; |
| |
| /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used |
| in cselib_clear_table() for fast emptying. */ |
| static unsigned int *used_regs; |
| static unsigned int n_used_regs; |
| |
| /* We pass this to cselib_invalidate_mem to invalidate all of |
| memory for a non-const call instruction. */ |
| static GTY(()) rtx callmem; |
| |
| /* Set by discard_useless_locs if it deleted the last location of any |
| value. */ |
| static int values_became_useless; |
| |
| /* Used as stop element of the containing_mem list so we can check |
| presence in the list by checking the next pointer. */ |
| static cselib_val dummy_val; |
| |
| /* If non-NULL, value of the eliminated arg_pointer_rtx or frame_pointer_rtx |
| that is constant through the whole function and should never be |
| eliminated. */ |
| static cselib_val *cfa_base_preserved_val; |
| static unsigned int cfa_base_preserved_regno = INVALID_REGNUM; |
| |
| /* Used to list all values that contain memory reference. |
| May or may not contain the useless values - the list is compacted |
| each time memory is invalidated. */ |
| static cselib_val *first_containing_mem = &dummy_val; |
| |
| static object_allocator<elt_list> elt_list_pool ("elt_list"); |
| static object_allocator<elt_loc_list> elt_loc_list_pool ("elt_loc_list"); |
| static object_allocator<cselib_val> cselib_val_pool ("cselib_val_list"); |
| |
| static pool_allocator value_pool ("value", RTX_CODE_SIZE (VALUE)); |
| |
| /* If nonnull, cselib will call this function before freeing useless |
| VALUEs. A VALUE is deemed useless if its "locs" field is null. */ |
| void (*cselib_discard_hook) (cselib_val *); |
| |
| /* If nonnull, cselib will call this function before recording sets or |
| even clobbering outputs of INSN. All the recorded sets will be |
| represented in the array sets[n_sets]. new_val_min can be used to |
| tell whether values present in sets are introduced by this |
| instruction. */ |
| void (*cselib_record_sets_hook) (rtx_insn *insn, struct cselib_set *sets, |
| int n_sets); |
| |
| |
| |
| /* Allocate a struct elt_list and fill in its two elements with the |
| arguments. */ |
| |
| static inline struct elt_list * |
| new_elt_list (struct elt_list *next, cselib_val *elt) |
| { |
| elt_list *el = elt_list_pool.allocate (); |
| el->next = next; |
| el->elt = elt; |
| return el; |
| } |
| |
| /* Allocate a struct elt_loc_list with LOC and prepend it to VAL's loc |
| list. */ |
| |
| static inline void |
| new_elt_loc_list (cselib_val *val, rtx loc) |
| { |
| struct elt_loc_list *el, *next = val->locs; |
| |
| gcc_checking_assert (!next || !next->setting_insn |
| || !DEBUG_INSN_P (next->setting_insn) |
| || cselib_current_insn == next->setting_insn); |
| |
| /* If we're creating the first loc in a debug insn context, we've |
| just created a debug value. Count it. */ |
| if (!next && cselib_current_insn && DEBUG_INSN_P (cselib_current_insn)) |
| n_debug_values++; |
| |
| val = canonical_cselib_val (val); |
| next = val->locs; |
| |
| if (GET_CODE (loc) == VALUE) |
| { |
| loc = canonical_cselib_val (CSELIB_VAL_PTR (loc))->val_rtx; |
| |
| gcc_checking_assert (PRESERVED_VALUE_P (loc) |
| == PRESERVED_VALUE_P (val->val_rtx)); |
| |
| if (val->val_rtx == loc) |
| return; |
| else if (val->uid > CSELIB_VAL_PTR (loc)->uid) |
| { |
| /* Reverse the insertion. */ |
| new_elt_loc_list (CSELIB_VAL_PTR (loc), val->val_rtx); |
| return; |
| } |
| |
| gcc_checking_assert (val->uid < CSELIB_VAL_PTR (loc)->uid); |
| |
| if (CSELIB_VAL_PTR (loc)->locs) |
| { |
| /* Bring all locs from LOC to VAL. */ |
| for (el = CSELIB_VAL_PTR (loc)->locs; el->next; el = el->next) |
| { |
| /* Adjust values that have LOC as canonical so that VAL |
| becomes their canonical. */ |
| if (el->loc && GET_CODE (el->loc) == VALUE) |
| { |
| gcc_checking_assert (CSELIB_VAL_PTR (el->loc)->locs->loc |
| == loc); |
| CSELIB_VAL_PTR (el->loc)->locs->loc = val->val_rtx; |
| } |
| } |
| el->next = val->locs; |
| next = val->locs = CSELIB_VAL_PTR (loc)->locs; |
| } |
| |
| if (CSELIB_VAL_PTR (loc)->addr_list) |
| { |
| /* Bring in addr_list into canonical node. */ |
| struct elt_list *last = CSELIB_VAL_PTR (loc)->addr_list; |
| while (last->next) |
| last = last->next; |
| last->next = val->addr_list; |
| val->addr_list = CSELIB_VAL_PTR (loc)->addr_list; |
| CSELIB_VAL_PTR (loc)->addr_list = NULL; |
| } |
| |
| if (CSELIB_VAL_PTR (loc)->next_containing_mem != NULL |
| && val->next_containing_mem == NULL) |
| { |
| /* Add VAL to the containing_mem list after LOC. LOC will |
| be removed when we notice it doesn't contain any |
| MEMs. */ |
| val->next_containing_mem = CSELIB_VAL_PTR (loc)->next_containing_mem; |
| CSELIB_VAL_PTR (loc)->next_containing_mem = val; |
| } |
| |
| /* Chain LOC back to VAL. */ |
| el = elt_loc_list_pool.allocate (); |
| el->loc = val->val_rtx; |
| el->setting_insn = cselib_current_insn; |
| el->next = NULL; |
| CSELIB_VAL_PTR (loc)->locs = el; |
| } |
| |
| el = elt_loc_list_pool.allocate (); |
| el->loc = loc; |
| el->setting_insn = cselib_current_insn; |
| el->next = next; |
| val->locs = el; |
| } |
| |
| /* Promote loc L to a nondebug cselib_current_insn if L is marked as |
| originating from a debug insn, maintaining the debug values |
| count. */ |
| |
| static inline void |
| promote_debug_loc (struct elt_loc_list *l) |
| { |
| if (l && l->setting_insn && DEBUG_INSN_P (l->setting_insn) |
| && (!cselib_current_insn || !DEBUG_INSN_P (cselib_current_insn))) |
| { |
| n_debug_values--; |
| l->setting_insn = cselib_current_insn; |
| if (cselib_preserve_constants && l->next) |
| { |
| gcc_assert (l->next->setting_insn |
| && DEBUG_INSN_P (l->next->setting_insn) |
| && !l->next->next); |
| l->next->setting_insn = cselib_current_insn; |
| } |
| else |
| gcc_assert (!l->next); |
| } |
| } |
| |
| /* The elt_list at *PL is no longer needed. Unchain it and free its |
| storage. */ |
| |
| static inline void |
| unchain_one_elt_list (struct elt_list **pl) |
| { |
| struct elt_list *l = *pl; |
| |
| *pl = l->next; |
| elt_list_pool.remove (l); |
| } |
| |
| /* Likewise for elt_loc_lists. */ |
| |
| static void |
| unchain_one_elt_loc_list (struct elt_loc_list **pl) |
| { |
| struct elt_loc_list *l = *pl; |
| |
| *pl = l->next; |
| elt_loc_list_pool.remove (l); |
| } |
| |
| /* Likewise for cselib_vals. This also frees the addr_list associated with |
| V. */ |
| |
| static void |
| unchain_one_value (cselib_val *v) |
| { |
| while (v->addr_list) |
| unchain_one_elt_list (&v->addr_list); |
| |
| cselib_val_pool.remove (v); |
| } |
| |
| /* Remove all entries from the hash table. Also used during |
| initialization. */ |
| |
| void |
| cselib_clear_table (void) |
| { |
| cselib_reset_table (1); |
| } |
| |
| /* Return TRUE if V is a constant, a function invariant or a VALUE |
| equivalence; FALSE otherwise. */ |
| |
| static bool |
| invariant_or_equiv_p (cselib_val *v) |
| { |
| struct elt_loc_list *l; |
| |
| if (v == cfa_base_preserved_val) |
| return true; |
| |
| /* Keep VALUE equivalences around. */ |
| for (l = v->locs; l; l = l->next) |
| if (GET_CODE (l->loc) == VALUE) |
| return true; |
| |
| if (v->locs != NULL |
| && v->locs->next == NULL) |
| { |
| if (CONSTANT_P (v->locs->loc) |
| && (GET_CODE (v->locs->loc) != CONST |
| || !references_value_p (v->locs->loc, 0))) |
| return true; |
| /* Although a debug expr may be bound to different expressions, |
| we can preserve it as if it was constant, to get unification |
| and proper merging within var-tracking. */ |
| if (GET_CODE (v->locs->loc) == DEBUG_EXPR |
| || GET_CODE (v->locs->loc) == DEBUG_IMPLICIT_PTR |
| || GET_CODE (v->locs->loc) == ENTRY_VALUE |
| || GET_CODE (v->locs->loc) == DEBUG_PARAMETER_REF) |
| return true; |
| |
| /* (plus (value V) (const_int C)) is invariant iff V is invariant. */ |
| if (GET_CODE (v->locs->loc) == PLUS |
| && CONST_INT_P (XEXP (v->locs->loc, 1)) |
| && GET_CODE (XEXP (v->locs->loc, 0)) == VALUE |
| && invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (v->locs->loc, 0)))) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /* Remove from hash table all VALUEs except constants, function |
| invariants and VALUE equivalences. */ |
| |
| int |
| preserve_constants_and_equivs (cselib_val **x, void *info ATTRIBUTE_UNUSED) |
| { |
| cselib_val *v = *x; |
| |
| if (invariant_or_equiv_p (v)) |
| { |
| cselib_hasher::key lookup = { |
| GET_MODE (v->val_rtx), v->val_rtx, VOIDmode |
| }; |
| cselib_val **slot |
| = cselib_preserved_hash_table->find_slot_with_hash (&lookup, |
| v->hash, INSERT); |
| gcc_assert (!*slot); |
| *slot = v; |
| } |
| |
| cselib_hash_table->clear_slot (x); |
| |
| return 1; |
| } |
| |
| /* Remove all entries from the hash table, arranging for the next |
| value to be numbered NUM. */ |
| |
| void |
| cselib_reset_table (unsigned int num) |
| { |
| unsigned int i; |
| |
| max_value_regs = 0; |
| |
| if (cfa_base_preserved_val) |
| { |
| unsigned int regno = cfa_base_preserved_regno; |
| unsigned int new_used_regs = 0; |
| for (i = 0; i < n_used_regs; i++) |
| if (used_regs[i] == regno) |
| { |
| new_used_regs = 1; |
| continue; |
| } |
| else |
| REG_VALUES (used_regs[i]) = 0; |
| gcc_assert (new_used_regs == 1); |
| n_used_regs = new_used_regs; |
| used_regs[0] = regno; |
| max_value_regs |
| = hard_regno_nregs (regno, |
| GET_MODE (cfa_base_preserved_val->locs->loc)); |
| |
| /* If cfa_base is sp + const_int, need to preserve also the |
| SP_DERIVED_VALUE_P value. */ |
| for (struct elt_loc_list *l = cfa_base_preserved_val->locs; |
| l; l = l->next) |
| if (GET_CODE (l->loc) == PLUS |
| && GET_CODE (XEXP (l->loc, 0)) == VALUE |
| && SP_DERIVED_VALUE_P (XEXP (l->loc, 0)) |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| { |
| if (! invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (l->loc, 0)))) |
| { |
| rtx val = cfa_base_preserved_val->val_rtx; |
| rtx_insn *save_cselib_current_insn = cselib_current_insn; |
| cselib_current_insn = l->setting_insn; |
| new_elt_loc_list (CSELIB_VAL_PTR (XEXP (l->loc, 0)), |
| plus_constant (Pmode, val, |
| -UINTVAL (XEXP (l->loc, 1)))); |
| cselib_current_insn = save_cselib_current_insn; |
| } |
| break; |
| } |
| } |
| else |
| { |
| for (i = 0; i < n_used_regs; i++) |
| REG_VALUES (used_regs[i]) = 0; |
| n_used_regs = 0; |
| } |
| |
| if (cselib_preserve_constants) |
| cselib_hash_table->traverse <void *, preserve_constants_and_equivs> (NULL); |
| else |
| { |
| cselib_hash_table->empty (); |
| gcc_checking_assert (!cselib_any_perm_equivs); |
| } |
| |
| n_useless_values = 0; |
| n_useless_debug_values = 0; |
| n_debug_values = 0; |
| |
| next_uid = num; |
| |
| first_containing_mem = &dummy_val; |
| } |
| |
| /* Return the number of the next value that will be generated. */ |
| |
| unsigned int |
| cselib_get_next_uid (void) |
| { |
| return next_uid; |
| } |
| |
| /* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE, |
| INSERTing if requested. When X is part of the address of a MEM, |
| MEMMODE should specify the mode of the MEM. */ |
| |
| static cselib_val ** |
| cselib_find_slot (machine_mode mode, rtx x, hashval_t hash, |
| enum insert_option insert, machine_mode memmode) |
| { |
| cselib_val **slot = NULL; |
| cselib_hasher::key lookup = { mode, x, memmode }; |
| if (cselib_preserve_constants) |
| slot = cselib_preserved_hash_table->find_slot_with_hash (&lookup, hash, |
| NO_INSERT); |
| if (!slot) |
| slot = cselib_hash_table->find_slot_with_hash (&lookup, hash, insert); |
| return slot; |
| } |
| |
| /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we |
| only return true for values which point to a cselib_val whose value |
| element has been set to zero, which implies the cselib_val will be |
| removed. */ |
| |
| int |
| references_value_p (const_rtx x, int only_useless) |
| { |
| const enum rtx_code code = GET_CODE (x); |
| const char *fmt = GET_RTX_FORMAT (code); |
| int i, j; |
| |
| if (GET_CODE (x) == VALUE |
| && (! only_useless |
| || (CSELIB_VAL_PTR (x)->locs == 0 && !PRESERVED_VALUE_P (x)))) |
| return 1; |
| |
| for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
| { |
| if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless)) |
| return 1; |
| else if (fmt[i] == 'E') |
| for (j = 0; j < XVECLEN (x, i); j++) |
| if (references_value_p (XVECEXP (x, i, j), only_useless)) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* Return true if V is a useless VALUE and can be discarded as such. */ |
| |
| static bool |
| cselib_useless_value_p (cselib_val *v) |
| { |
| return (v->locs == 0 |
| && !PRESERVED_VALUE_P (v->val_rtx) |
| && !SP_DERIVED_VALUE_P (v->val_rtx)); |
| } |
| |
| /* For all locations found in X, delete locations that reference useless |
| values (i.e. values without any location). Called through |
| htab_traverse. */ |
| |
| int |
| discard_useless_locs (cselib_val **x, void *info ATTRIBUTE_UNUSED) |
| { |
| cselib_val *v = *x; |
| struct elt_loc_list **p = &v->locs; |
| bool had_locs = v->locs != NULL; |
| rtx_insn *setting_insn = v->locs ? v->locs->setting_insn : NULL; |
| |
| while (*p) |
| { |
| if (references_value_p ((*p)->loc, 1)) |
| unchain_one_elt_loc_list (p); |
| else |
| p = &(*p)->next; |
| } |
| |
| if (had_locs && cselib_useless_value_p (v)) |
| { |
| if (setting_insn && DEBUG_INSN_P (setting_insn)) |
| n_useless_debug_values++; |
| else |
| n_useless_values++; |
| values_became_useless = 1; |
| } |
| return 1; |
| } |
| |
| /* If X is a value with no locations, remove it from the hashtable. */ |
| |
| int |
| discard_useless_values (cselib_val **x, void *info ATTRIBUTE_UNUSED) |
| { |
| cselib_val *v = *x; |
| |
| if (v->locs == 0 && cselib_useless_value_p (v)) |
| { |
| if (cselib_discard_hook) |
| cselib_discard_hook (v); |
| |
| CSELIB_VAL_PTR (v->val_rtx) = NULL; |
| cselib_hash_table->clear_slot (x); |
| unchain_one_value (v); |
| n_useless_values--; |
| } |
| |
| return 1; |
| } |
| |
| /* Clean out useless values (i.e. those which no longer have locations |
| associated with them) from the hash table. */ |
| |
| static void |
| remove_useless_values (void) |
| { |
| cselib_val **p, *v; |
| |
| /* First pass: eliminate locations that reference the value. That in |
| turn can make more values useless. */ |
| do |
| { |
| values_became_useless = 0; |
| cselib_hash_table->traverse <void *, discard_useless_locs> (NULL); |
| } |
| while (values_became_useless); |
| |
| /* Second pass: actually remove the values. */ |
| |
| p = &first_containing_mem; |
| for (v = *p; v != &dummy_val; v = v->next_containing_mem) |
| if (v->locs && v == canonical_cselib_val (v)) |
| { |
| *p = v; |
| p = &(*p)->next_containing_mem; |
| } |
| *p = &dummy_val; |
| |
| n_useless_values += n_useless_debug_values; |
| n_debug_values -= n_useless_debug_values; |
| n_useless_debug_values = 0; |
| |
| cselib_hash_table->traverse <void *, discard_useless_values> (NULL); |
| |
| gcc_assert (!n_useless_values); |
| } |
| |
| /* Arrange for a value to not be removed from the hash table even if |
| it becomes useless. */ |
| |
| void |
| cselib_preserve_value (cselib_val *v) |
| { |
| PRESERVED_VALUE_P (v->val_rtx) = 1; |
| } |
| |
| /* Test whether a value is preserved. */ |
| |
| bool |
| cselib_preserved_value_p (cselib_val *v) |
| { |
| return PRESERVED_VALUE_P (v->val_rtx); |
| } |
| |
| /* Arrange for a REG value to be assumed constant through the whole function, |
| never invalidated and preserved across cselib_reset_table calls. */ |
| |
| void |
| cselib_preserve_cfa_base_value (cselib_val *v, unsigned int regno) |
| { |
| if (cselib_preserve_constants |
| && v->locs |
| && REG_P (v->locs->loc)) |
| { |
| cfa_base_preserved_val = v; |
| cfa_base_preserved_regno = regno; |
| } |
| } |
| |
| /* Clean all non-constant expressions in the hash table, but retain |
| their values. */ |
| |
| void |
| cselib_preserve_only_values (void) |
| { |
| int i; |
| |
| for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
| cselib_invalidate_regno (i, reg_raw_mode[i]); |
| |
| cselib_invalidate_mem (callmem); |
| |
| remove_useless_values (); |
| |
| gcc_assert (first_containing_mem == &dummy_val); |
| } |
| |
| /* Arrange for a value to be marked as based on stack pointer |
| for find_base_term purposes. */ |
| |
| void |
| cselib_set_value_sp_based (cselib_val *v) |
| { |
| SP_BASED_VALUE_P (v->val_rtx) = 1; |
| } |
| |
| /* Test whether a value is based on stack pointer for |
| find_base_term purposes. */ |
| |
| bool |
| cselib_sp_based_value_p (cselib_val *v) |
| { |
| return SP_BASED_VALUE_P (v->val_rtx); |
| } |
| |
| /* Return the mode in which a register was last set. If X is not a |
| register, return its mode. If the mode in which the register was |
| set is not known, or the value was already clobbered, return |
| VOIDmode. */ |
| |
| machine_mode |
| cselib_reg_set_mode (const_rtx x) |
| { |
| if (!REG_P (x)) |
| return GET_MODE (x); |
| |
| if (REG_VALUES (REGNO (x)) == NULL |
| || REG_VALUES (REGNO (x))->elt == NULL) |
| return VOIDmode; |
| |
| return GET_MODE (REG_VALUES (REGNO (x))->elt->val_rtx); |
| } |
| |
| /* If x is a PLUS or an autoinc operation, expand the operation, |
| storing the offset, if any, in *OFF. */ |
| |
| static rtx |
| autoinc_split (rtx x, rtx *off, machine_mode memmode) |
| { |
| switch (GET_CODE (x)) |
| { |
| case PLUS: |
| *off = XEXP (x, 1); |
| x = XEXP (x, 0); |
| break; |
| |
| case PRE_DEC: |
| if (memmode == VOIDmode) |
| return x; |
| |
| *off = gen_int_mode (-GET_MODE_SIZE (memmode), GET_MODE (x)); |
| x = XEXP (x, 0); |
| break; |
| |
| case PRE_INC: |
| if (memmode == VOIDmode) |
| return x; |
| |
| *off = gen_int_mode (GET_MODE_SIZE (memmode), GET_MODE (x)); |
| x = XEXP (x, 0); |
| break; |
| |
| case PRE_MODIFY: |
| x = XEXP (x, 1); |
| break; |
| |
| case POST_DEC: |
| case POST_INC: |
| case POST_MODIFY: |
| x = XEXP (x, 0); |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (GET_MODE (x) == Pmode |
| && (REG_P (x) || MEM_P (x) || GET_CODE (x) == VALUE) |
| && (*off == NULL_RTX || CONST_INT_P (*off))) |
| { |
| cselib_val *e; |
| if (GET_CODE (x) == VALUE) |
| e = CSELIB_VAL_PTR (x); |
| else |
| e = cselib_lookup (x, GET_MODE (x), 0, memmode); |
| if (e) |
| { |
| if (SP_DERIVED_VALUE_P (e->val_rtx) |
| && (*off == NULL_RTX || *off == const0_rtx)) |
| { |
| *off = NULL_RTX; |
| return e->val_rtx; |
| } |
| for (struct elt_loc_list *l = e->locs; l; l = l->next) |
| if (GET_CODE (l->loc) == PLUS |
| && GET_CODE (XEXP (l->loc, 0)) == VALUE |
| && SP_DERIVED_VALUE_P (XEXP (l->loc, 0)) |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| { |
| if (*off == NULL_RTX) |
| *off = XEXP (l->loc, 1); |
| else |
| *off = plus_constant (Pmode, *off, |
| INTVAL (XEXP (l->loc, 1))); |
| if (*off == const0_rtx) |
| *off = NULL_RTX; |
| return XEXP (l->loc, 0); |
| } |
| } |
| } |
| return x; |
| } |
| |
| /* Return nonzero if we can prove that X and Y contain the same value, |
| taking our gathered information into account. MEMMODE holds the |
| mode of the enclosing MEM, if any, as required to deal with autoinc |
| addressing modes. If X and Y are not (known to be) part of |
| addresses, MEMMODE should be VOIDmode. */ |
| |
| int |
| rtx_equal_for_cselib_1 (rtx x, rtx y, machine_mode memmode, int depth) |
| { |
| enum rtx_code code; |
| const char *fmt; |
| int i; |
| |
| if (REG_P (x) || MEM_P (x)) |
| { |
| cselib_val *e = cselib_lookup (x, GET_MODE (x), 0, memmode); |
| |
| if (e) |
| x = e->val_rtx; |
| } |
| |
| if (REG_P (y) || MEM_P (y)) |
| { |
| cselib_val *e = cselib_lookup (y, GET_MODE (y), 0, memmode); |
| |
| if (e) |
| y = e->val_rtx; |
| } |
| |
| if (x == y) |
| return 1; |
| |
| if (GET_CODE (x) == VALUE) |
| { |
| cselib_val *e = canonical_cselib_val (CSELIB_VAL_PTR (x)); |
| struct elt_loc_list *l; |
| |
| if (GET_CODE (y) == VALUE) |
| return e == canonical_cselib_val (CSELIB_VAL_PTR (y)); |
| |
| if ((SP_DERIVED_VALUE_P (x) |
| || SP_DERIVED_VALUE_P (e->val_rtx)) |
| && GET_MODE (y) == Pmode) |
| { |
| rtx yoff = NULL; |
| rtx yr = autoinc_split (y, &yoff, memmode); |
| if ((yr == x || yr == e->val_rtx) && yoff == NULL_RTX) |
| return 1; |
| } |
| |
| if (depth == 128) |
| return 0; |
| |
| for (l = e->locs; l; l = l->next) |
| { |
| rtx t = l->loc; |
| |
| /* Avoid infinite recursion. We know we have the canonical |
| value, so we can just skip any values in the equivalence |
| list. */ |
| if (REG_P (t) || MEM_P (t) || GET_CODE (t) == VALUE) |
| continue; |
| else if (rtx_equal_for_cselib_1 (t, y, memmode, depth + 1)) |
| return 1; |
| } |
| |
| return 0; |
| } |
| else if (GET_CODE (y) == VALUE) |
| { |
| cselib_val *e = canonical_cselib_val (CSELIB_VAL_PTR (y)); |
| struct elt_loc_list *l; |
| |
| if ((SP_DERIVED_VALUE_P (y) |
| || SP_DERIVED_VALUE_P (e->val_rtx)) |
| && GET_MODE (x) == Pmode) |
| { |
| rtx xoff = NULL; |
| rtx xr = autoinc_split (x, &xoff, memmode); |
| if ((xr == y || xr == e->val_rtx) && xoff == NULL_RTX) |
| return 1; |
| } |
| |
| if (depth == 128) |
| return 0; |
| |
| for (l = e->locs; l; l = l->next) |
| { |
| rtx t = l->loc; |
| |
| if (REG_P (t) || MEM_P (t) || GET_CODE (t) == VALUE) |
| continue; |
| else if (rtx_equal_for_cselib_1 (x, t, memmode, depth + 1)) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| if (GET_MODE (x) != GET_MODE (y)) |
| return 0; |
| |
| if (GET_CODE (x) != GET_CODE (y) |
| || (GET_CODE (x) == PLUS |
| && GET_MODE (x) == Pmode |
| && CONST_INT_P (XEXP (x, 1)) |
| && CONST_INT_P (XEXP (y, 1)))) |
| { |
| rtx xorig = x, yorig = y; |
| rtx xoff = NULL, yoff = NULL; |
| |
| x = autoinc_split (x, &xoff, memmode); |
| y = autoinc_split (y, &yoff, memmode); |
| |
| /* Don't recurse if nothing changed. */ |
| if (x != xorig || y != yorig) |
| { |
| if (!xoff != !yoff) |
| return 0; |
| |
| if (xoff && !rtx_equal_for_cselib_1 (xoff, yoff, memmode, depth)) |
| return 0; |
| |
| return rtx_equal_for_cselib_1 (x, y, memmode, depth); |
| } |
| |
| if (GET_CODE (xorig) != GET_CODE (yorig)) |
| return 0; |
| } |
| |
| /* These won't be handled correctly by the code below. */ |
| switch (GET_CODE (x)) |
| { |
| CASE_CONST_UNIQUE: |
| case DEBUG_EXPR: |
| return 0; |
| |
| case CONST_VECTOR: |
| if (!same_vector_encodings_p (x, y)) |
| return false; |
| break; |
| |
| case DEBUG_IMPLICIT_PTR: |
| return DEBUG_IMPLICIT_PTR_DECL (x) |
| == DEBUG_IMPLICIT_PTR_DECL (y); |
| |
| case DEBUG_PARAMETER_REF: |
| return DEBUG_PARAMETER_REF_DECL (x) |
| == DEBUG_PARAMETER_REF_DECL (y); |
| |
| case ENTRY_VALUE: |
| /* ENTRY_VALUEs are function invariant, it is thus undesirable to |
| use rtx_equal_for_cselib_1 to compare the operands. */ |
| return rtx_equal_p (ENTRY_VALUE_EXP (x), ENTRY_VALUE_EXP (y)); |
| |
| case LABEL_REF: |
| return label_ref_label (x) == label_ref_label (y); |
| |
| case REG: |
| return REGNO (x) == REGNO (y); |
| |
| case MEM: |
| /* We have to compare any autoinc operations in the addresses |
| using this MEM's mode. */ |
| return rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 0), GET_MODE (x), |
| depth); |
| |
| default: |
| break; |
| } |
| |
| code = GET_CODE (x); |
| fmt = GET_RTX_FORMAT (code); |
| |
| for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
| { |
| int j; |
| |
| switch (fmt[i]) |
| { |
| case 'w': |
| if (XWINT (x, i) != XWINT (y, i)) |
| return 0; |
| break; |
| |
| case 'n': |
| case 'i': |
| if (XINT (x, i) != XINT (y, i)) |
| return 0; |
| break; |
| |
| case 'p': |
| if (maybe_ne (SUBREG_BYTE (x), SUBREG_BYTE (y))) |
| return 0; |
| break; |
| |
| case 'V': |
| case 'E': |
| /* Two vectors must have the same length. */ |
| if (XVECLEN (x, i) != XVECLEN (y, i)) |
| return 0; |
| |
| /* And the corresponding elements must match. */ |
| for (j = 0; j < XVECLEN (x, i); j++) |
| if (! rtx_equal_for_cselib_1 (XVECEXP (x, i, j), |
| XVECEXP (y, i, j), memmode, depth)) |
| return 0; |
| break; |
| |
| case 'e': |
| if (i == 1 |
| && targetm.commutative_p (x, UNKNOWN) |
| && rtx_equal_for_cselib_1 (XEXP (x, 1), XEXP (y, 0), memmode, |
| depth) |
| && rtx_equal_for_cselib_1 (XEXP (x, 0), XEXP (y, 1), memmode, |
| depth)) |
| return 1; |
| if (! rtx_equal_for_cselib_1 (XEXP (x, i), XEXP (y, i), memmode, |
| depth)) |
| return 0; |
| break; |
| |
| case 'S': |
| case 's': |
| if (strcmp (XSTR (x, i), XSTR (y, i))) |
| return 0; |
| break; |
| |
| case 'u': |
| /* These are just backpointers, so they don't matter. */ |
| break; |
| |
| case '0': |
| case 't': |
| break; |
| |
| /* It is believed that rtx's at this level will never |
| contain anything but integers and other rtx's, |
| except for within LABEL_REFs and SYMBOL_REFs. */ |
| default: |
| gcc_unreachable (); |
| } |
| } |
| return 1; |
| } |
| |
| /* Helper function for cselib_hash_rtx. Arguments like for cselib_hash_rtx, |
| except that it hashes (plus:P x c). */ |
| |
| static unsigned int |
| cselib_hash_plus_const_int (rtx x, HOST_WIDE_INT c, int create, |
| machine_mode memmode) |
| { |
| cselib_val *e = cselib_lookup (x, GET_MODE (x), create, memmode); |
| if (! e) |
| return 0; |
| |
| if (! SP_DERIVED_VALUE_P (e->val_rtx)) |
| for (struct elt_loc_list *l = e->locs; l; l = l->next) |
| if (GET_CODE (l->loc) == PLUS |
| && GET_CODE (XEXP (l->loc, 0)) == VALUE |
| && SP_DERIVED_VALUE_P (XEXP (l->loc, 0)) |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| { |
| e = CSELIB_VAL_PTR (XEXP (l->loc, 0)); |
| c = trunc_int_for_mode (c + UINTVAL (XEXP (l->loc, 1)), Pmode); |
| break; |
| } |
| if (c == 0) |
| return e->hash; |
| |
| unsigned hash = (unsigned) PLUS + (unsigned) GET_MODE (x); |
| hash += e->hash; |
| unsigned int tem_hash = (unsigned) CONST_INT + (unsigned) VOIDmode; |
| tem_hash += ((unsigned) CONST_INT << 7) + (unsigned HOST_WIDE_INT) c; |
| if (tem_hash == 0) |
| tem_hash = (unsigned int) CONST_INT; |
| hash += tem_hash; |
| return hash ? hash : 1 + (unsigned int) PLUS; |
| } |
| |
| /* Hash an rtx. Return 0 if we couldn't hash the rtx. |
| For registers and memory locations, we look up their cselib_val structure |
| and return its VALUE element. |
| Possible reasons for return 0 are: the object is volatile, or we couldn't |
| find a register or memory location in the table and CREATE is zero. If |
| CREATE is nonzero, table elts are created for regs and mem. |
| N.B. this hash function returns the same hash value for RTXes that |
| differ only in the order of operands, thus it is suitable for comparisons |
| that take commutativity into account. |
| If we wanted to also support associative rules, we'd have to use a different |
| strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) . |
| MEMMODE indicates the mode of an enclosing MEM, and it's only |
| used to compute autoinc values. |
| We used to have a MODE argument for hashing for CONST_INTs, but that |
| didn't make sense, since it caused spurious hash differences between |
| (set (reg:SI 1) (const_int)) |
| (plus:SI (reg:SI 2) (reg:SI 1)) |
| and |
| (plus:SI (reg:SI 2) (const_int)) |
| If the mode is important in any context, it must be checked specifically |
| in a comparison anyway, since relying on hash differences is unsafe. */ |
| |
| static unsigned int |
| cselib_hash_rtx (rtx x, int create, machine_mode memmode) |
| { |
| cselib_val *e; |
| poly_int64 offset; |
| int i, j; |
| enum rtx_code code; |
| const char *fmt; |
| unsigned int hash = 0; |
| |
| code = GET_CODE (x); |
| hash += (unsigned) code + (unsigned) GET_MODE (x); |
| |
| switch (code) |
| { |
| case VALUE: |
| e = CSELIB_VAL_PTR (x); |
| return e->hash; |
| |
| case MEM: |
| case REG: |
| e = cselib_lookup (x, GET_MODE (x), create, memmode); |
| if (! e) |
| return 0; |
| |
| return e->hash; |
| |
| case DEBUG_EXPR: |
| hash += ((unsigned) DEBUG_EXPR << 7) |
| + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x)); |
| return hash ? hash : (unsigned int) DEBUG_EXPR; |
| |
| case DEBUG_IMPLICIT_PTR: |
| hash += ((unsigned) DEBUG_IMPLICIT_PTR << 7) |
| + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x)); |
| return hash ? hash : (unsigned int) DEBUG_IMPLICIT_PTR; |
| |
| case DEBUG_PARAMETER_REF: |
| hash += ((unsigned) DEBUG_PARAMETER_REF << 7) |
| + DECL_UID (DEBUG_PARAMETER_REF_DECL (x)); |
| return hash ? hash : (unsigned int) DEBUG_PARAMETER_REF; |
| |
| case ENTRY_VALUE: |
| /* ENTRY_VALUEs are function invariant, thus try to avoid |
| recursing on argument if ENTRY_VALUE is one of the |
| forms emitted by expand_debug_expr, otherwise |
| ENTRY_VALUE hash would depend on the current value |
| in some register or memory. */ |
| if (REG_P (ENTRY_VALUE_EXP (x))) |
| hash += (unsigned int) REG |
| + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x)) |
| + (unsigned int) REGNO (ENTRY_VALUE_EXP (x)); |
| else if (MEM_P (ENTRY_VALUE_EXP (x)) |
| && REG_P (XEXP (ENTRY_VALUE_EXP (x), 0))) |
| hash += (unsigned int) MEM |
| + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x), 0)) |
| + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x), 0)); |
| else |
| hash += cselib_hash_rtx (ENTRY_VALUE_EXP (x), create, memmode); |
| return hash ? hash : (unsigned int) ENTRY_VALUE; |
| |
| case CONST_INT: |
| hash += ((unsigned) CONST_INT << 7) + UINTVAL (x); |
| return hash ? hash : (unsigned int) CONST_INT; |
| |
| case CONST_WIDE_INT: |
| for (i = 0; i < CONST_WIDE_INT_NUNITS (x); i++) |
| hash += CONST_WIDE_INT_ELT (x, i); |
| return hash; |
| |
| case CONST_POLY_INT: |
| { |
| inchash::hash h; |
| h.add_int (hash); |
| for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i) |
| h.add_wide_int (CONST_POLY_INT_COEFFS (x)[i]); |
| return h.end (); |
| } |
| |
| case CONST_DOUBLE: |
| /* This is like the general case, except that it only counts |
| the integers representing the constant. */ |
| hash += (unsigned) code + (unsigned) GET_MODE (x); |
| if (TARGET_SUPPORTS_WIDE_INT == 0 && GET_MODE (x) == VOIDmode) |
| hash += ((unsigned) CONST_DOUBLE_LOW (x) |
| + (unsigned) CONST_DOUBLE_HIGH (x)); |
| else |
| hash += real_hash (CONST_DOUBLE_REAL_VALUE (x)); |
| return hash ? hash : (unsigned int) CONST_DOUBLE; |
| |
| case CONST_FIXED: |
| hash += (unsigned int) code + (unsigned int) GET_MODE (x); |
| hash += fixed_hash (CONST_FIXED_VALUE (x)); |
| return hash ? hash : (unsigned int) CONST_FIXED; |
| |
| case CONST_VECTOR: |
| { |
| int units; |
| rtx elt; |
| |
| units = const_vector_encoded_nelts (x); |
| |
| for (i = 0; i < units; ++i) |
| { |
| elt = CONST_VECTOR_ENCODED_ELT (x, i); |
| hash += cselib_hash_rtx (elt, 0, memmode); |
| } |
| |
| return hash; |
| } |
| |
| /* Assume there is only one rtx object for any given label. */ |
| case LABEL_REF: |
| /* We don't hash on the address of the CODE_LABEL to avoid bootstrap |
| differences and differences between each stage's debugging dumps. */ |
| hash += (((unsigned int) LABEL_REF << 7) |
| + CODE_LABEL_NUMBER (label_ref_label (x))); |
| return hash ? hash : (unsigned int) LABEL_REF; |
| |
| case SYMBOL_REF: |
| { |
| /* Don't hash on the symbol's address to avoid bootstrap differences. |
| Different hash values may cause expressions to be recorded in |
| different orders and thus different registers to be used in the |
| final assembler. This also avoids differences in the dump files |
| between various stages. */ |
| unsigned int h = 0; |
| const unsigned char *p = (const unsigned char *) XSTR (x, 0); |
| |
| while (*p) |
| h += (h << 7) + *p++; /* ??? revisit */ |
| |
| hash += ((unsigned int) SYMBOL_REF << 7) + h; |
| return hash ? hash : (unsigned int) SYMBOL_REF; |
| } |
| |
| case PRE_DEC: |
| case PRE_INC: |
| /* We can't compute these without knowing the MEM mode. */ |
| gcc_assert (memmode != VOIDmode); |
| offset = GET_MODE_SIZE (memmode); |
| if (code == PRE_DEC) |
| offset = -offset; |
| /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes |
| like (mem:MEMMODE (plus (reg) (const_int I))). */ |
| if (GET_MODE (x) == Pmode |
| && (REG_P (XEXP (x, 0)) |
| || MEM_P (XEXP (x, 0)) |
| || GET_CODE (XEXP (x, 0)) == VALUE)) |
| { |
| HOST_WIDE_INT c; |
| if (offset.is_constant (&c)) |
| return cselib_hash_plus_const_int (XEXP (x, 0), |
| trunc_int_for_mode (c, Pmode), |
| create, memmode); |
| } |
| hash = ((unsigned) PLUS + (unsigned) GET_MODE (x) |
| + cselib_hash_rtx (XEXP (x, 0), create, memmode) |
| + cselib_hash_rtx (gen_int_mode (offset, GET_MODE (x)), |
| create, memmode)); |
| return hash ? hash : 1 + (unsigned) PLUS; |
| |
| case PRE_MODIFY: |
| gcc_assert (memmode != VOIDmode); |
| return cselib_hash_rtx (XEXP (x, 1), create, memmode); |
| |
| case POST_DEC: |
| case POST_INC: |
| case POST_MODIFY: |
| gcc_assert (memmode != VOIDmode); |
| return cselib_hash_rtx (XEXP (x, 0), create, memmode); |
| |
| case PC: |
| case CC0: |
| case CALL: |
| case UNSPEC_VOLATILE: |
| return 0; |
| |
| case ASM_OPERANDS: |
| if (MEM_VOLATILE_P (x)) |
| return 0; |
| |
| break; |
| |
| case PLUS: |
| if (GET_MODE (x) == Pmode |
| && (REG_P (XEXP (x, 0)) |
| || MEM_P (XEXP (x, 0)) |
| || GET_CODE (XEXP (x, 0)) == VALUE) |
| && CONST_INT_P (XEXP (x, 1))) |
| return cselib_hash_plus_const_int (XEXP (x, 0), INTVAL (XEXP (x, 1)), |
| create, memmode); |
| break; |
| |
| default: |
| break; |
| } |
| |
| i = GET_RTX_LENGTH (code) - 1; |
| fmt = GET_RTX_FORMAT (code); |
| for (; i >= 0; i--) |
| { |
| switch (fmt[i]) |
| { |
| case 'e': |
| { |
| rtx tem = XEXP (x, i); |
| unsigned int tem_hash = cselib_hash_rtx (tem, create, memmode); |
| |
| if (tem_hash == 0) |
| return 0; |
| |
| hash += tem_hash; |
| } |
| break; |
| case 'E': |
| for (j = 0; j < XVECLEN (x, i); j++) |
| { |
| unsigned int tem_hash |
| = cselib_hash_rtx (XVECEXP (x, i, j), create, memmode); |
| |
| if (tem_hash == 0) |
| return 0; |
| |
| hash += tem_hash; |
| } |
| break; |
| |
| case 's': |
| { |
| const unsigned char *p = (const unsigned char *) XSTR (x, i); |
| |
| if (p) |
| while (*p) |
| hash += *p++; |
| break; |
| } |
| |
| case 'i': |
| hash += XINT (x, i); |
| break; |
| |
| case 'p': |
| hash += constant_lower_bound (SUBREG_BYTE (x)); |
| break; |
| |
| case '0': |
| case 't': |
| /* unused */ |
| break; |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| |
| return hash ? hash : 1 + (unsigned int) GET_CODE (x); |
| } |
| |
| /* Create a new value structure for VALUE and initialize it. The mode of the |
| value is MODE. */ |
| |
| static inline cselib_val * |
| new_cselib_val (unsigned int hash, machine_mode mode, rtx x) |
| { |
| cselib_val *e = cselib_val_pool.allocate (); |
| |
| gcc_assert (hash); |
| gcc_assert (next_uid); |
| |
| e->hash = hash; |
| e->uid = next_uid++; |
| /* We use an alloc pool to allocate this RTL construct because it |
| accounts for about 8% of the overall memory usage. We know |
| precisely when we can have VALUE RTXen (when cselib is active) |
| so we don't need to put them in garbage collected memory. |
| ??? Why should a VALUE be an RTX in the first place? */ |
| e->val_rtx = (rtx_def*) value_pool.allocate (); |
| memset (e->val_rtx, 0, RTX_HDR_SIZE); |
| PUT_CODE (e->val_rtx, VALUE); |
| PUT_MODE (e->val_rtx, mode); |
| CSELIB_VAL_PTR (e->val_rtx) = e; |
| e->addr_list = 0; |
| e->locs = 0; |
| e->next_containing_mem = 0; |
| |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| { |
| fprintf (dump_file, "cselib value %u:%u ", e->uid, hash); |
| if (flag_dump_noaddr || flag_dump_unnumbered) |
| fputs ("# ", dump_file); |
| else |
| fprintf (dump_file, "%p ", (void*)e); |
| print_rtl_single (dump_file, x); |
| fputc ('\n', dump_file); |
| } |
| |
| return e; |
| } |
| |
| /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that |
| contains the data at this address. X is a MEM that represents the |
| value. Update the two value structures to represent this situation. */ |
| |
| static void |
| add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x) |
| { |
| addr_elt = canonical_cselib_val (addr_elt); |
| mem_elt = canonical_cselib_val (mem_elt); |
| |
| /* Avoid duplicates. */ |
| addr_space_t as = MEM_ADDR_SPACE (x); |
| for (elt_loc_list *l = mem_elt->locs; l; l = l->next) |
| if (MEM_P (l->loc) |
| && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt |
| && MEM_ADDR_SPACE (l->loc) == as) |
| { |
| promote_debug_loc (l); |
| return; |
| } |
| |
| addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt); |
| new_elt_loc_list (mem_elt, |
| replace_equiv_address_nv (x, addr_elt->val_rtx)); |
| if (mem_elt->next_containing_mem == NULL) |
| { |
| mem_elt->next_containing_mem = first_containing_mem; |
| first_containing_mem = mem_elt; |
| } |
| } |
| |
| /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx. |
| If CREATE, make a new one if we haven't seen it before. */ |
| |
| static cselib_val * |
| cselib_lookup_mem (rtx x, int create) |
| { |
| machine_mode mode = GET_MODE (x); |
| machine_mode addr_mode; |
| cselib_val **slot; |
| cselib_val *addr; |
| cselib_val *mem_elt; |
| |
| if (MEM_VOLATILE_P (x) || mode == BLKmode |
| || !cselib_record_memory |
| || (FLOAT_MODE_P (mode) && flag_float_store)) |
| return 0; |
| |
| addr_mode = GET_MODE (XEXP (x, 0)); |
| if (addr_mode == VOIDmode) |
| addr_mode = Pmode; |
| |
| /* Look up the value for the address. */ |
| addr = cselib_lookup (XEXP (x, 0), addr_mode, create, mode); |
| if (! addr) |
| return 0; |
| addr = canonical_cselib_val (addr); |
| |
| /* Find a value that describes a value of our mode at that address. */ |
| addr_space_t as = MEM_ADDR_SPACE (x); |
| for (elt_list *l = addr->addr_list; l; l = l->next) |
| if (GET_MODE (l->elt->val_rtx) == mode) |
| { |
| for (elt_loc_list *l2 = l->elt->locs; l2; l2 = l2->next) |
| if (MEM_P (l2->loc) && MEM_ADDR_SPACE (l2->loc) == as) |
| { |
| promote_debug_loc (l->elt->locs); |
| return l->elt; |
| } |
| } |
| |
| if (! create) |
| return 0; |
| |
| mem_elt = new_cselib_val (next_uid, mode, x); |
| add_mem_for_addr (addr, mem_elt, x); |
| slot = cselib_find_slot (mode, x, mem_elt->hash, INSERT, VOIDmode); |
| *slot = mem_elt; |
| return mem_elt; |
| } |
| |
| /* Search through the possible substitutions in P. We prefer a non reg |
| substitution because this allows us to expand the tree further. If |
| we find, just a reg, take the lowest regno. There may be several |
| non-reg results, we just take the first one because they will all |
| expand to the same place. */ |
| |
| static rtx |
| expand_loc (struct elt_loc_list *p, struct expand_value_data *evd, |
| int max_depth) |
| { |
| rtx reg_result = NULL; |
| unsigned int regno = UINT_MAX; |
| struct elt_loc_list *p_in = p; |
| |
| for (; p; p = p->next) |
| { |
| /* Return these right away to avoid returning stack pointer based |
| expressions for frame pointer and vice versa, which is something |
| that would confuse DSE. See the comment in cselib_expand_value_rtx_1 |
| for more details. */ |
| if (REG_P (p->loc) |
| && (REGNO (p->loc) == STACK_POINTER_REGNUM |
| || REGNO (p->loc) == FRAME_POINTER_REGNUM |
| || REGNO (p->loc) == HARD_FRAME_POINTER_REGNUM |
| || REGNO (p->loc) == cfa_base_preserved_regno)) |
| return p->loc; |
| /* Avoid infinite recursion trying to expand a reg into a |
| the same reg. */ |
| if ((REG_P (p->loc)) |
| && (REGNO (p->loc) < regno) |
| && !bitmap_bit_p (evd->regs_active, REGNO (p->loc))) |
| { |
| reg_result = p->loc; |
| regno = REGNO (p->loc); |
| } |
| /* Avoid infinite recursion and do not try to expand the |
| value. */ |
| else if (GET_CODE (p->loc) == VALUE |
| && CSELIB_VAL_PTR (p->loc)->locs == p_in) |
| continue; |
| else if (!REG_P (p->loc)) |
| { |
| rtx result, note; |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| { |
| print_inline_rtx (dump_file, p->loc, 0); |
| fprintf (dump_file, "\n"); |
| } |
| if (GET_CODE (p->loc) == LO_SUM |
| && GET_CODE (XEXP (p->loc, 1)) == SYMBOL_REF |
| && p->setting_insn |
| && (note = find_reg_note (p->setting_insn, REG_EQUAL, NULL_RTX)) |
| && XEXP (note, 0) == XEXP (p->loc, 1)) |
| return XEXP (p->loc, 1); |
| result = cselib_expand_value_rtx_1 (p->loc, evd, max_depth - 1); |
| if (result) |
| return result; |
| } |
| |
| } |
| |
| if (regno != UINT_MAX) |
| { |
| rtx result; |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| fprintf (dump_file, "r%d\n", regno); |
| |
| result = cselib_expand_value_rtx_1 (reg_result, evd, max_depth - 1); |
| if (result) |
| return result; |
| } |
| |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| { |
| if (reg_result) |
| { |
| print_inline_rtx (dump_file, reg_result, 0); |
| fprintf (dump_file, "\n"); |
| } |
| else |
| fprintf (dump_file, "NULL\n"); |
| } |
| return reg_result; |
| } |
| |
| |
| /* Forward substitute and expand an expression out to its roots. |
| This is the opposite of common subexpression. Because local value |
| numbering is such a weak optimization, the expanded expression is |
| pretty much unique (not from a pointer equals point of view but |
| from a tree shape point of view. |
| |
| This function returns NULL if the expansion fails. The expansion |
| will fail if there is no value number for one of the operands or if |
| one of the operands has been overwritten between the current insn |
| and the beginning of the basic block. For instance x has no |
| expansion in: |
| |
| r1 <- r1 + 3 |
| x <- r1 + 8 |
| |
| REGS_ACTIVE is a scratch bitmap that should be clear when passing in. |
| It is clear on return. */ |
| |
| rtx |
| cselib_expand_value_rtx (rtx orig, bitmap regs_active, int max_depth) |
| { |
| struct expand_value_data evd; |
| |
| evd.regs_active = regs_active; |
| evd.callback = NULL; |
| evd.callback_arg = NULL; |
| evd.dummy = false; |
| |
| return cselib_expand_value_rtx_1 (orig, &evd, max_depth); |
| } |
| |
| /* Same as cselib_expand_value_rtx, but using a callback to try to |
| resolve some expressions. The CB function should return ORIG if it |
| can't or does not want to deal with a certain RTX. Any other |
| return value, including NULL, will be used as the expansion for |
| VALUE, without any further changes. */ |
| |
| rtx |
| cselib_expand_value_rtx_cb (rtx orig, bitmap regs_active, int max_depth, |
| cselib_expand_callback cb, void *data) |
| { |
| struct expand_value_data evd; |
| |
| evd.regs_active = regs_active; |
| evd.callback = cb; |
| evd.callback_arg = data; |
| evd.dummy = false; |
| |
| return cselib_expand_value_rtx_1 (orig, &evd, max_depth); |
| } |
| |
| /* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied |
| or simplified. Useful to find out whether cselib_expand_value_rtx_cb |
| would return NULL or non-NULL, without allocating new rtx. */ |
| |
| bool |
| cselib_dummy_expand_value_rtx_cb (rtx orig, bitmap regs_active, int max_depth, |
| cselib_expand_callback cb, void *data) |
| { |
| struct expand_value_data evd; |
| |
| evd.regs_active = regs_active; |
| evd.callback = cb; |
| evd.callback_arg = data; |
| evd.dummy = true; |
| |
| return cselib_expand_value_rtx_1 (orig, &evd, max_depth) != NULL; |
| } |
| |
| /* Internal implementation of cselib_expand_value_rtx and |
| cselib_expand_value_rtx_cb. */ |
| |
| static rtx |
| cselib_expand_value_rtx_1 (rtx orig, struct expand_value_data *evd, |
| int max_depth) |
| { |
| rtx copy, scopy; |
| int i, j; |
| RTX_CODE code; |
| const char *format_ptr; |
| machine_mode mode; |
| |
| code = GET_CODE (orig); |
| |
| /* For the context of dse, if we end up expand into a huge tree, we |
| will not have a useful address, so we might as well just give up |
| quickly. */ |
| if (max_depth <= 0) |
| return NULL; |
| |
| switch (code) |
| { |
| case REG: |
| { |
| struct elt_list *l = REG_VALUES (REGNO (orig)); |
| |
| if (l && l->elt == NULL) |
| l = l->next; |
| for (; l; l = l->next) |
| if (GET_MODE (l->elt->val_rtx) == GET_MODE (orig)) |
| { |
| rtx result; |
| unsigned regno = REGNO (orig); |
| |
| /* The only thing that we are not willing to do (this |
| is requirement of dse and if others potential uses |
| need this function we should add a parm to control |
| it) is that we will not substitute the |
| STACK_POINTER_REGNUM, FRAME_POINTER or the |
| HARD_FRAME_POINTER. |
| |
| These expansions confuses the code that notices that |
| stores into the frame go dead at the end of the |
| function and that the frame is not effected by calls |
| to subroutines. If you allow the |
| STACK_POINTER_REGNUM substitution, then dse will |
| think that parameter pushing also goes dead which is |
| wrong. If you allow the FRAME_POINTER or the |
| HARD_FRAME_POINTER then you lose the opportunity to |
| make the frame assumptions. */ |
| if (regno == STACK_POINTER_REGNUM |
| || regno == FRAME_POINTER_REGNUM |
| || regno == HARD_FRAME_POINTER_REGNUM |
| || regno == cfa_base_preserved_regno) |
| return orig; |
| |
| bitmap_set_bit (evd->regs_active, regno); |
| |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| fprintf (dump_file, "expanding: r%d into: ", regno); |
| |
| result = expand_loc (l->elt->locs, evd, max_depth); |
| bitmap_clear_bit (evd->regs_active, regno); |
| |
| if (result) |
| return result; |
| else |
| return orig; |
| } |
| return orig; |
| } |
| |
| CASE_CONST_ANY: |
| case SYMBOL_REF: |
| case CODE_LABEL: |
| case PC: |
| case CC0: |
| case SCRATCH: |
| /* SCRATCH must be shared because they represent distinct values. */ |
| return orig; |
| case CLOBBER: |
| if (REG_P (XEXP (orig, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig, 0)))) |
| return orig; |
| break; |
| |
| case CONST: |
| if (shared_const_p (orig)) |
| return orig; |
| break; |
| |
| case SUBREG: |
| { |
| rtx subreg; |
| |
| if (evd->callback) |
| { |
| subreg = evd->callback (orig, evd->regs_active, max_depth, |
| evd->callback_arg); |
| if (subreg != orig) |
| return subreg; |
| } |
| |
| subreg = cselib_expand_value_rtx_1 (SUBREG_REG (orig), evd, |
| max_depth - 1); |
| if (!subreg) |
| return NULL; |
| scopy = simplify_gen_subreg (GET_MODE (orig), subreg, |
| GET_MODE (SUBREG_REG (orig)), |
| SUBREG_BYTE (orig)); |
| if (scopy == NULL |
| || (GET_CODE (scopy) == SUBREG |
| && !REG_P (SUBREG_REG (scopy)) |
| && !MEM_P (SUBREG_REG (scopy)))) |
| return NULL; |
| |
| return scopy; |
| } |
| |
| case VALUE: |
| { |
| rtx result; |
| |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| { |
| fputs ("\nexpanding ", dump_file); |
| print_rtl_single (dump_file, orig); |
| fputs (" into...", dump_file); |
| } |
| |
| if (evd->callback) |
| { |
| result = evd->callback (orig, evd->regs_active, max_depth, |
| evd->callback_arg); |
| |
| if (result != orig) |
| return result; |
| } |
| |
| result = expand_loc (CSELIB_VAL_PTR (orig)->locs, evd, max_depth); |
| return result; |
| } |
| |
| case DEBUG_EXPR: |
| if (evd->callback) |
| return evd->callback (orig, evd->regs_active, max_depth, |
| evd->callback_arg); |
| return orig; |
| |
| default: |
| break; |
| } |
| |
| /* Copy the various flags, fields, and other information. We assume |
| that all fields need copying, and then clear the fields that should |
| not be copied. That is the sensible default behavior, and forces |
| us to explicitly document why we are *not* copying a flag. */ |
| if (evd->dummy) |
| copy = NULL; |
| else |
| copy = shallow_copy_rtx (orig); |
| |
| format_ptr = GET_RTX_FORMAT (code); |
| |
| for (i = 0; i < GET_RTX_LENGTH (code); i++) |
| switch (*format_ptr++) |
| { |
| case 'e': |
| if (XEXP (orig, i) != NULL) |
| { |
| rtx result = cselib_expand_value_rtx_1 (XEXP (orig, i), evd, |
| max_depth - 1); |
| if (!result) |
| return NULL; |
| if (copy) |
| XEXP (copy, i) = result; |
| } |
| break; |
| |
| case 'E': |
| case 'V': |
| if (XVEC (orig, i) != NULL) |
| { |
| if (copy) |
| XVEC (copy, i) = rtvec_alloc (XVECLEN (orig, i)); |
| for (j = 0; j < XVECLEN (orig, i); j++) |
| { |
| rtx result = cselib_expand_value_rtx_1 (XVECEXP (orig, i, j), |
| evd, max_depth - 1); |
| if (!result) |
| return NULL; |
| if (copy) |
| XVECEXP (copy, i, j) = result; |
| } |
| } |
| break; |
| |
| case 't': |
| case 'w': |
| case 'i': |
| case 's': |
| case 'S': |
| case 'T': |
| case 'u': |
| case 'B': |
| case '0': |
| /* These are left unchanged. */ |
| break; |
| |
| default: |
| gcc_unreachable (); |
| } |
| |
| if (evd->dummy) |
| return orig; |
| |
| mode = GET_MODE (copy); |
| /* If an operand has been simplified into CONST_INT, which doesn't |
| have a mode and the mode isn't derivable from whole rtx's mode, |
| try simplify_*_operation first with mode from original's operand |
| and as a fallback wrap CONST_INT into gen_rtx_CONST. */ |
| scopy = copy; |
| switch (GET_RTX_CLASS (code)) |
| { |
| case RTX_UNARY: |
| if (CONST_INT_P (XEXP (copy, 0)) |
| && GET_MODE (XEXP (orig, 0)) != VOIDmode) |
| { |
| scopy = simplify_unary_operation (code, mode, XEXP (copy, 0), |
| GET_MODE (XEXP (orig, 0))); |
| if (scopy) |
| return scopy; |
| } |
| break; |
| case RTX_COMM_ARITH: |
| case RTX_BIN_ARITH: |
| /* These expressions can derive operand modes from the whole rtx's mode. */ |
| break; |
| case RTX_TERNARY: |
| case RTX_BITFIELD_OPS: |
| if (CONST_INT_P (XEXP (copy, 0)) |
| && GET_MODE (XEXP (orig, 0)) != VOIDmode) |
| { |
| scopy = simplify_ternary_operation (code, mode, |
| GET_MODE (XEXP (orig, 0)), |
| XEXP (copy, 0), XEXP (copy, 1), |
| XEXP (copy, 2)); |
| if (scopy) |
| return scopy; |
| } |
| break; |
| case RTX_COMPARE: |
| case RTX_COMM_COMPARE: |
| if (CONST_INT_P (XEXP (copy, 0)) |
| && GET_MODE (XEXP (copy, 1)) == VOIDmode |
| && (GET_MODE (XEXP (orig, 0)) != VOIDmode |
| || GET_MODE (XEXP (orig, 1)) != VOIDmode)) |
| { |
| scopy = simplify_relational_operation (code, mode, |
| (GET_MODE (XEXP (orig, 0)) |
| != VOIDmode) |
| ? GET_MODE (XEXP (orig, 0)) |
| : GET_MODE (XEXP (orig, 1)), |
| XEXP (copy, 0), |
| XEXP (copy, 1)); |
| if (scopy) |
| return scopy; |
| } |
| break; |
| default: |
| break; |
| } |
| scopy = simplify_rtx (copy); |
| if (scopy) |
| return scopy; |
| return copy; |
| } |
| |
| /* Walk rtx X and replace all occurrences of REG and MEM subexpressions |
| with VALUE expressions. This way, it becomes independent of changes |
| to registers and memory. |
| X isn't actually modified; if modifications are needed, new rtl is |
| allocated. However, the return value can share rtl with X. |
| If X is within a MEM, MEMMODE must be the mode of the MEM. */ |
| |
| rtx |
| cselib_subst_to_values (rtx x, machine_mode memmode) |
| { |
| enum rtx_code code = GET_CODE (x); |
| const char *fmt = GET_RTX_FORMAT (code); |
| cselib_val *e; |
| struct elt_list *l; |
| rtx copy = x; |
| int i; |
| poly_int64 offset; |
| |
| switch (code) |
| { |
| case REG: |
| l = REG_VALUES (REGNO (x)); |
| if (l && l->elt == NULL) |
| l = l->next; |
| for (; l; l = l->next) |
| if (GET_MODE (l->elt->val_rtx) == GET_MODE (x)) |
| return l->elt->val_rtx; |
| |
| gcc_unreachable (); |
| |
| case MEM: |
| e = cselib_lookup_mem (x, 0); |
| /* This used to happen for autoincrements, but we deal with them |
| properly now. Remove the if stmt for the next release. */ |
| if (! e) |
| { |
| /* Assign a value that doesn't match any other. */ |
| e = new_cselib_val (next_uid, GET_MODE (x), x); |
| } |
| return e->val_rtx; |
| |
| case ENTRY_VALUE: |
| e = cselib_lookup (x, GET_MODE (x), 0, memmode); |
| if (! e) |
| break; |
| return e->val_rtx; |
| |
| CASE_CONST_ANY: |
| return x; |
| |
| case PRE_DEC: |
| case PRE_INC: |
| gcc_assert (memmode != VOIDmode); |
| offset = GET_MODE_SIZE (memmode); |
| if (code == PRE_DEC) |
| offset = -offset; |
| return cselib_subst_to_values (plus_constant (GET_MODE (x), |
| XEXP (x, 0), offset), |
| memmode); |
| |
| case PRE_MODIFY: |
| gcc_assert (memmode != VOIDmode); |
| return cselib_subst_to_values (XEXP (x, 1), memmode); |
| |
| case POST_DEC: |
| case POST_INC: |
| case POST_MODIFY: |
| gcc_assert (memmode != VOIDmode); |
| return cselib_subst_to_values (XEXP (x, 0), memmode); |
| |
| case PLUS: |
| if (GET_MODE (x) == Pmode && CONST_INT_P (XEXP (x, 1))) |
| { |
| rtx t = cselib_subst_to_values (XEXP (x, 0), memmode); |
| if (GET_CODE (t) == VALUE) |
| { |
| if (SP_DERIVED_VALUE_P (t) && XEXP (x, 1) == const0_rtx) |
| return t; |
| for (struct elt_loc_list *l = CSELIB_VAL_PTR (t)->locs; |
| l; l = l->next) |
| if (GET_CODE (l->loc) == PLUS |
| && GET_CODE (XEXP (l->loc, 0)) == VALUE |
| && SP_DERIVED_VALUE_P (XEXP (l->loc, 0)) |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| return plus_constant (Pmode, l->loc, INTVAL (XEXP (x, 1))); |
| } |
| if (t != XEXP (x, 0)) |
| { |
| copy = shallow_copy_rtx (x); |
| XEXP (copy, 0) = t; |
| } |
| return copy; |
| } |
| |
| default: |
| break; |
| } |
| |
| for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) |
| { |
| if (fmt[i] == 'e') |
| { |
| rtx t = cselib_subst_to_values (XEXP (x, i), memmode); |
| |
| if (t != XEXP (x, i)) |
| { |
| if (x == copy) |
| copy = shallow_copy_rtx (x); |
| XEXP (copy, i) = t; |
| } |
| } |
| else if (fmt[i] == 'E') |
| { |
| int j; |
| |
| for (j = 0; j < XVECLEN (x, i); j++) |
| { |
| rtx t = cselib_subst_to_values (XVECEXP (x, i, j), memmode); |
| |
| if (t != XVECEXP (x, i, j)) |
| { |
| if (XVEC (x, i) == XVEC (copy, i)) |
| { |
| if (x == copy) |
| copy = shallow_copy_rtx (x); |
| XVEC (copy, i) = shallow_copy_rtvec (XVEC (x, i)); |
| } |
| XVECEXP (copy, i, j) = t; |
| } |
| } |
| } |
| } |
| |
| return copy; |
| } |
| |
| /* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */ |
| |
| rtx |
| cselib_subst_to_values_from_insn (rtx x, machine_mode memmode, rtx_insn *insn) |
| { |
| rtx ret; |
| gcc_assert (!cselib_current_insn); |
| cselib_current_insn = insn; |
| ret = cselib_subst_to_values (x, memmode); |
| cselib_current_insn = NULL; |
| return ret; |
| } |
| |
| /* Look up the rtl expression X in our tables and return the value it |
| has. If CREATE is zero, we return NULL if we don't know the value. |
| Otherwise, we create a new one if possible, using mode MODE if X |
| doesn't have a mode (i.e. because it's a constant). When X is part |
| of an address, MEMMODE should be the mode of the enclosing MEM if |
| we're tracking autoinc expressions. */ |
| |
| static cselib_val * |
| cselib_lookup_1 (rtx x, machine_mode mode, |
| int create, machine_mode memmode) |
| { |
| cselib_val **slot; |
| cselib_val *e; |
| unsigned int hashval; |
| |
| if (GET_MODE (x) != VOIDmode) |
| mode = GET_MODE (x); |
| |
| if (GET_CODE (x) == VALUE) |
| return CSELIB_VAL_PTR (x); |
| |
| if (REG_P (x)) |
| { |
| struct elt_list *l; |
| unsigned int i = REGNO (x); |
| |
| l = REG_VALUES (i); |
| if (l && l->elt == NULL) |
| l = l->next; |
| for (; l; l = l->next) |
| if (mode == GET_MODE (l->elt->val_rtx)) |
| { |
| promote_debug_loc (l->elt->locs); |
| return l->elt; |
| } |
| |
| if (! create) |
| return 0; |
| |
| if (i < FIRST_PSEUDO_REGISTER) |
| { |
| unsigned int n = hard_regno_nregs (i, mode); |
| |
| if (n > max_value_regs) |
| max_value_regs = n; |
| } |
| |
| e = new_cselib_val (next_uid, GET_MODE (x), x); |
| if (GET_MODE (x) == Pmode && x == stack_pointer_rtx) |
| SP_DERIVED_VALUE_P (e->val_rtx) = 1; |
| new_elt_loc_list (e, x); |
| |
| scalar_int_mode int_mode; |
| if (REG_VALUES (i) == 0) |
| { |
| /* Maintain the invariant that the first entry of |
| REG_VALUES, if present, must be the value used to set the |
| register, or NULL. */ |
| used_regs[n_used_regs++] = i; |
| REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL); |
| } |
| else if (cselib_preserve_constants |
| && is_int_mode (mode, &int_mode)) |
| { |
| /* During var-tracking, try harder to find equivalences |
| for SUBREGs. If a setter sets say a DImode register |
| and user uses that register only in SImode, add a lowpart |
| subreg location. */ |
| struct elt_list *lwider = NULL; |
| scalar_int_mode lmode; |
| l = REG_VALUES (i); |
| if (l && l->elt == NULL) |
| l = l->next; |
| for (; l; l = l->next) |
| if (is_int_mode (GET_MODE (l->elt->val_rtx), &lmode) |
| && GET_MODE_SIZE (lmode) > GET_MODE_SIZE (int_mode) |
| && (lwider == NULL |
| || partial_subreg_p (lmode, |
| GET_MODE (lwider->elt->val_rtx)))) |
| { |
| struct elt_loc_list *el; |
| if (i < FIRST_PSEUDO_REGISTER |
| && hard_regno_nregs (i, lmode) != 1) |
| continue; |
| for (el = l->elt->locs; el; el = el->next) |
| if (!REG_P (el->loc)) |
| break; |
| if (el) |
| lwider = l; |
| } |
| if (lwider) |
| { |
| rtx sub = lowpart_subreg (int_mode, lwider->elt->val_rtx, |
| GET_MODE (lwider->elt->val_rtx)); |
| if (sub) |
| new_elt_loc_list (e, sub); |
| } |
| } |
| REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e); |
| slot = cselib_find_slot (mode, x, e->hash, INSERT, memmode); |
| *slot = e; |
| return e; |
| } |
| |
| if (MEM_P (x)) |
| return cselib_lookup_mem (x, create); |
| |
| hashval = cselib_hash_rtx (x, create, memmode); |
| /* Can't even create if hashing is not possible. */ |
| if (! hashval) |
| return 0; |
| |
| slot = cselib_find_slot (mode, x, hashval, |
| create ? INSERT : NO_INSERT, memmode); |
| if (slot == 0) |
| return 0; |
| |
| e = (cselib_val *) *slot; |
| if (e) |
| return e; |
| |
| e = new_cselib_val (hashval, mode, x); |
| |
| /* We have to fill the slot before calling cselib_subst_to_values: |
| the hash table is inconsistent until we do so, and |
| cselib_subst_to_values will need to do lookups. */ |
| *slot = e; |
| rtx v = cselib_subst_to_values (x, memmode); |
| |
| /* If cselib_preserve_constants, we might get a SP_DERIVED_VALUE_P |
| VALUE that isn't in the hash tables anymore. */ |
| if (GET_CODE (v) == VALUE && SP_DERIVED_VALUE_P (v) && PRESERVED_VALUE_P (v)) |
| PRESERVED_VALUE_P (e->val_rtx) = 1; |
| |
| new_elt_loc_list (e, v); |
| return e; |
| } |
| |
| /* Wrapper for cselib_lookup, that indicates X is in INSN. */ |
| |
| cselib_val * |
| cselib_lookup_from_insn (rtx x, machine_mode mode, |
| int create, machine_mode memmode, rtx_insn *insn) |
| { |
| cselib_val *ret; |
| |
| gcc_assert (!cselib_current_insn); |
| cselib_current_insn = insn; |
| |
| ret = cselib_lookup (x, mode, create, memmode); |
| |
| cselib_current_insn = NULL; |
| |
| return ret; |
| } |
| |
| /* Wrapper for cselib_lookup_1, that logs the lookup result and |
| maintains invariants related with debug insns. */ |
| |
| cselib_val * |
| cselib_lookup (rtx x, machine_mode mode, |
| int create, machine_mode memmode) |
| { |
| cselib_val *ret = cselib_lookup_1 (x, mode, create, memmode); |
| |
| /* ??? Should we return NULL if we're not to create an entry, the |
| found loc is a debug loc and cselib_current_insn is not DEBUG? |
| If so, we should also avoid converting val to non-DEBUG; probably |
| easiest setting cselib_current_insn to NULL before the call |
| above. */ |
| |
| if (dump_file && (dump_flags & TDF_CSELIB)) |
| { |
| fputs ("cselib lookup ", dump_file); |
| print_inline_rtx (dump_file, x, 2); |
| fprintf (dump_file, " => %u:%u\n", |
| ret ? ret->uid : 0, |
| ret ? ret->hash : 0); |
| } |
| |
| return ret; |
| } |
| |
| /* Invalidate the value at *L, which is part of REG_VALUES (REGNO). */ |
| |
| static void |
| cselib_invalidate_regno_val (unsigned int regno, struct elt_list **l) |
| { |
| cselib_val *v = (*l)->elt; |
| if (*l == REG_VALUES (regno)) |
| { |
| /* Maintain the invariant that the first entry of |
| REG_VALUES, if present, must be the value used to set |
| the register, or NULL. This is also nice because |
| then we won't push the same regno onto user_regs |
| multiple times. */ |
| (*l)->elt = NULL; |
| l = &(*l)->next; |
| } |
| else |
| unchain_one_elt_list (l); |
| |
| v = canonical_cselib_val (v); |
| |
| bool had_locs = v->locs != NULL; |
| rtx_insn *setting_insn = v->locs ? v->locs->setting_insn : NULL; |
| |
| /* Now, we clear the mapping from value to reg. It must exist, so |
| this code will crash intentionally if it doesn't. */ |
| for (elt_loc_list **p = &v->locs; ; p = &(*p)->next) |
| { |
| rtx x = (*p)->loc; |
| |
| if (REG_P (x) && REGNO (x) == regno) |
| { |
| unchain_one_elt_loc_list (p); |
| break; |
| } |
| } |
| |
| if (had_locs && cselib_useless_value_p (v)) |
| { |
| if (setting_insn && DEBUG_INSN_P (setting_insn)) |
| n_useless_debug_values++; |
| else |
| n_useless_values++; |
| } |
| } |
| |
| /* Invalidate any entries in reg_values that overlap REGNO. This is called |
| if REGNO is changing. MODE is the mode of the assignment to REGNO, which |
| is used to determine how many hard registers are being changed. If MODE |
| is VOIDmode, then only REGNO is being changed; this is used when |
| invalidating call clobbered registers across a call. */ |
| |
| static void |
| cselib_invalidate_regno (unsigned int regno, machine_mode mode) |
| { |
| unsigned int endregno; |
| unsigned int i; |
| |
| /* If we see pseudos after reload, something is _wrong_. */ |
| gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER |
| || reg_renumber[regno] < 0); |
| |
| /* Determine the range of registers that must be invalidated. For |
| pseudos, only REGNO is affected. For hard regs, we must take MODE |
| into account, and we must also invalidate lower register numbers |
| if they contain values that overlap REGNO. */ |
| if (regno < FIRST_PSEUDO_REGISTER) |
| { |
| gcc_assert (mode != VOIDmode); |
| |
| if (regno < max_value_regs) |
| i = 0; |
| else |
| i = regno - max_value_regs; |
| |
| endregno = end_hard_regno (mode, regno); |
| } |
| else |
| { |
| i = regno; |
| endregno = regno + 1; |
| } |
| |
| for (; i < endregno; i++) |
| { |
| struct elt_list **l = ®_VALUES (i); |
| |
| /* Go through all known values for this reg; if it overlaps the range |
| we're invalidating, remove the value. */ |
| while (*l) |
| { |
| cselib_val *v = (*l)->elt; |
| unsigned int this_last = i; |
| |
| if (i < FIRST_PSEUDO_REGISTER && v != NULL) |
| this_last = end_hard_regno (GET_MODE (v->val_rtx), i) - 1; |
| |
| if (this_last < regno || v == NULL |
| || (v == cfa_base_preserved_val |
| && i == cfa_base_preserved_regno)) |
| { |
| l = &(*l)->next; |
| continue; |
| } |
| |
| /* We have an overlap. */ |
| cselib_invalidate_regno_val (i, l); |
| } |
| } |
| } |
| |
| /* Invalidate any locations in the table which are changed because of a |
| store to MEM_RTX. If this is called because of a non-const call |
| instruction, MEM_RTX is (mem:BLK const0_rtx). */ |
| |
| static void |
| cselib_invalidate_mem (rtx mem_rtx) |
| { |
| cselib_val **vp, *v, *next; |
| int num_mems = 0; |
| rtx mem_addr; |
| |
| mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0))); |
| mem_rtx = canon_rtx (mem_rtx); |
| |
| vp = &first_containing_mem; |
| for (v = *vp; v != &dummy_val; v = next) |
| { |
| bool has_mem = false; |
| struct elt_loc_list **p = &v->locs; |
| bool had_locs = v->locs != NULL; |
| rtx_insn *setting_insn = v->locs ? v->locs->setting_insn : NULL; |
| |
| while (*p) |
| { |
| rtx x = (*p)->loc; |
| cselib_val *addr; |
| struct elt_list **mem_chain; |
| |
| /* MEMs may occur in locations only at the top level; below |
| that every MEM or REG is substituted by its VALUE. */ |
| if (!MEM_P (x)) |
| { |
| p = &(*p)->next; |
| continue; |
| } |
| if (num_mems < param_max_cselib_memory_locations |
| && ! canon_anti_dependence (x, false, mem_rtx, |
| GET_MODE (mem_rtx), mem_addr)) |
| { |
| has_mem = true; |
| num_mems++; |
| p = &(*p)->next; |
| continue; |
| } |
| |
| /* This one overlaps. */ |
| /* We must have a mapping from this MEM's address to the |
| value (E). Remove that, too. */ |
| addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0, GET_MODE (x)); |
| addr = canonical_cselib_val (addr); |
| gcc_checking_assert (v == canonical_cselib_val (v)); |
| mem_chain = &addr->addr_list; |
| for (;;) |
| { |
| cselib_val *canon = canonical_cselib_val ((*mem_chain)->elt); |
| |
| if (canon == v) |
| { |
| unchain_one_elt_list (mem_chain); |
| break; |
| } |
| |
| /* Record canonicalized elt. */ |
| (*mem_chain)->elt = canon; |
| |
| mem_chain = &(*mem_chain)->next; |
| } |
| |
| unchain_one_elt_loc_list (p); |
| } |
| |
| if (had_locs && cselib_useless_value_p (v)) |
| { |
| if (setting_insn && DEBUG_INSN_P (setting_insn)) |
| n_useless_debug_values++; |
| else |
| n_useless_values++; |
| } |
| |
| next = v->next_containing_mem; |
| if (has_mem) |
| { |
| *vp = v; |
| vp = &(*vp)->next_containing_mem; |
| } |
| else |
| v->next_containing_mem = NULL; |
| } |
| *vp = &dummy_val; |
| } |
| |
| /* Invalidate DEST. */ |
| |
| void |
| cselib_invalidate_rtx (rtx dest) |
| { |
| while (GET_CODE (dest) == SUBREG |
| || GET_CODE (dest) == ZERO_EXTRACT |
| || GET_CODE (dest) == STRICT_LOW_PART) |
| dest = XEXP (dest, 0); |
| |
| if (REG_P (dest)) |
| cselib_invalidate_regno (REGNO (dest), GET_MODE (dest)); |
| else if (MEM_P (dest)) |
| cselib_invalidate_mem (dest); |
| } |
| |
| /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */ |
| |
| static void |
| cselib_invalidate_rtx_note_stores (rtx dest, const_rtx, |
| void *data ATTRIBUTE_UNUSED) |
| { |
| cselib_invalidate_rtx (dest); |
| } |
| |
| /* Record the result of a SET instruction. DEST is being set; the source |
| contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT |
| describes its address. */ |
| |
| static void |
| cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt) |
| { |
| if (src_elt == 0 || side_effects_p (dest)) |
| return; |
| |
| if (REG_P (dest)) |
| { |
| unsigned int dreg = REGNO (dest); |
| if (dreg < FIRST_PSEUDO_REGISTER) |
| { |
| unsigned int n = REG_NREGS (dest); |
| |
| if (n > max_value_regs) |
| max_value_regs = n; |
| } |
| |
| if (REG_VALUES (dreg) == 0) |
| { |
| used_regs[n_used_regs++] = dreg; |
| REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt); |
| } |
| else |
| { |
| /* The register should have been invalidated. */ |
| gcc_assert (REG_VALUES (dreg)->elt == 0); |
| REG_VALUES (dreg)->elt = src_elt; |
| } |
| |
| if (cselib_useless_value_p (src_elt)) |
| n_useless_values--; |
| new_elt_loc_list (src_elt, dest); |
| } |
| else if (MEM_P (dest) && dest_addr_elt != 0 |
| && cselib_record_memory) |
| { |
| if (cselib_useless_value_p (src_elt)) |
| n_useless_values--; |
| add_mem_for_addr (dest_addr_elt, src_elt, dest); |
| } |
| } |
| |
| /* Make ELT and X's VALUE equivalent to each other at INSN. */ |
| |
| void |
| cselib_add_permanent_equiv (cselib_val *elt, rtx x, rtx_insn *insn) |
| { |
| cselib_val *nelt; |
| rtx_insn *save_cselib_current_insn = cselib_current_insn; |
| |
| gcc_checking_assert (elt); |
| gcc_checking_assert (PRESERVED_VALUE_P (elt->val_rtx)); |
| gcc_checking_assert (!side_effects_p (x)); |
| |
| cselib_current_insn = insn; |
| |
| nelt = cselib_lookup (x, GET_MODE (elt->val_rtx), 1, VOIDmode); |
| |
| if (nelt != elt) |
| { |
| cselib_any_perm_equivs = true; |
| |
| if (!PRESERVED_VALUE_P (nelt->val_rtx)) |
| cselib_preserve_value (nelt); |
| |
| new_elt_loc_list (nelt, elt->val_rtx); |
| } |
| |
| cselib_current_insn = save_cselib_current_insn; |
| } |
| |
| /* Return TRUE if any permanent equivalences have been recorded since |
| the table was last initialized. */ |
| bool |
| cselib_have_permanent_equivalences (void) |
| { |
| return cselib_any_perm_equivs; |
| } |
| |
| /* Record stack_pointer_rtx to be equal to |
| (plus:P cfa_base_preserved_val offset). Used by var-tracking |
| at the start of basic blocks for !frame_pointer_needed functions. */ |
| |
| void |
| cselib_record_sp_cfa_base_equiv (HOST_WIDE_INT offset, rtx_insn *insn) |
| { |
| rtx sp_derived_value = NULL_RTX; |
| for (struct elt_loc_list *l = cfa_base_preserved_val->locs; l; l = l->next) |
| if (GET_CODE (l->loc) == VALUE |
| && SP_DERIVED_VALUE_P (l->loc)) |
| { |
| sp_derived_value = l->loc; |
| break; |
| } |
| else if (GET_CODE (l->loc) == PLUS |
| && GET_CODE (XEXP (l->loc, 0)) == VALUE |
| && SP_DERIVED_VALUE_P (XEXP (l->loc, 0)) |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| { |
| sp_derived_value = XEXP (l->loc, 0); |
| offset = offset + UINTVAL (XEXP (l->loc, 1)); |
| break; |
| } |
| if (sp_derived_value == NULL_RTX) |
| return; |
| cselib_val *val |
| = cselib_lookup_from_insn (plus_constant (Pmode, sp_derived_value, offset), |
| Pmode, 1, VOIDmode, insn); |
| if (val != NULL) |
| { |
| PRESERVED_VALUE_P (val->val_rtx) = 1; |
| cselib_record_set (stack_pointer_rtx, val, NULL); |
| } |
| } |
| |
| /* Return true if V is SP_DERIVED_VALUE_P (or SP_DERIVED_VALUE_P + CONST_INT) |
| that can be expressed using cfa_base_preserved_val + CONST_INT. */ |
| |
| bool |
| cselib_sp_derived_value_p (cselib_val *v) |
| { |
| if (!SP_DERIVED_VALUE_P (v->val_rtx)) |
| for (struct elt_loc_list *l = v->locs; l; l = l->next) |
| if (GET_CODE (l->loc) == PLUS |
| && GET_CODE (XEXP (l->loc, 0)) == VALUE |
| && SP_DERIVED_VALUE_P (XEXP (l->loc, 0)) |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| v = CSELIB_VAL_PTR (XEXP (l->loc, 0)); |
| if (!SP_DERIVED_VALUE_P (v->val_rtx)) |
| return false; |
| for (struct elt_loc_list *l = v->locs; l; l = l->next) |
| if (l->loc == cfa_base_preserved_val->val_rtx) |
| return true; |
| else if (GET_CODE (l->loc) == PLUS |
| && XEXP (l->loc, 0) == cfa_base_preserved_val->val_rtx |
| && CONST_INT_P (XEXP (l->loc, 1))) |
| return true; |
| return false; |
| } |
| |
| /* There is no good way to determine how many elements there can be |
| in a PARALLEL. Since it's fairly cheap, use a really large number. */ |
| #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2) |
| |
| struct cselib_record_autoinc_data |
| { |
| struct cselib_set *sets; |
| int n_sets; |
| }; |
| |
| /* Callback for for_each_inc_dec. Records in ARG the SETs implied by |
| autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */ |
| |
| static int |
| cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED, rtx op ATTRIBUTE_UNUSED, |
| rtx dest, rtx src, rtx srcoff, void *arg) |
| { |
| struct cselib_record_autoinc_data *data; |
| data = (struct cselib_record_autoinc_data *)arg; |
| |
| data->sets[data->n_sets].dest = dest; |
| |
| if (srcoff) |
| data->sets[data->n_sets].src = gen_rtx_PLUS (GET_MODE (src), src, srcoff); |
| else |
| data->sets[data->n_sets].src = src; |
| |
| data->n_sets++; |
| |
| return 0; |
| } |
| |
| /* Record the effects of any sets and autoincs in INSN. */ |
| static void |
| cselib_record_sets (rtx_insn *insn) |
| { |
| int n_sets = 0; |
| int i; |
| struct cselib_set sets[MAX_SETS]; |
| rtx cond = 0; |
| int n_sets_before_autoinc; |
| int n_strict_low_parts = 0; |
| struct cselib_record_autoinc_data data; |
| |
| rtx body = PATTERN (insn); |
| if (GET_CODE (body) == COND_EXEC) |
| { |
| cond = COND_EXEC_TEST (body); |
| body = COND_EXEC_CODE (body); |
| } |
| |
| /* Find all sets. */ |
| if (GET_CODE (body) == SET) |
| { |
| sets[0].src = SET_SRC (body); |
| sets[0].dest = SET_DEST (body); |
| n_sets = 1; |
| } |
| else if (GET_CODE (body) == PARALLEL) |
| { |
| /* Look through the PARALLEL and record the values being |
| set, if possible. Also handle any CLOBBERs. */ |
| for (i = XVECLEN (body, 0) - 1; i >= 0; --i) |
| { |
| rtx x = XVECEXP (body, 0, i); |
| |
| if (GET_CODE (x) == SET) |
| { |
| sets[n_sets].src = SET_SRC (x); |
| sets[n_sets].dest = SET_DEST (x); |
| n_sets++; |
| } |
| } |
| } |
| |
| if (n_sets == 1 |
| && MEM_P (sets[0].src) |
| && !cselib_record_memory |
| && MEM_READONLY_P (sets[0].src)) |
| { |
| rtx note = find_reg_equal_equiv_note (insn); |
| |
| if (note && CONSTANT_P (XEXP (note, 0))) |
| sets[0].src = XEXP (note, 0); |
| } |
| |
| data.sets = sets; |
| data.n_sets = n_sets_before_autoinc = n_sets; |
| for_each_inc_dec (PATTERN (insn), cselib_record_autoinc_cb, &data); |
| n_sets = data.n_sets; |
| |
| /* Look up the values that are read. Do this before invalidating the |
| locations that are written. */ |
| for (i = 0; i < n_sets; i++) |
| { |
| rtx dest = sets[i].dest; |
| rtx orig = dest; |
| |
| /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for |
| the low part after invalidating any knowledge about larger modes. */ |
| if (GET_CODE (sets[i].dest) == STRICT_LOW_PART) |
| sets[i].dest = dest = XEXP (dest, 0); |
| |
| /* We don't know how to record anything but REG or MEM. */ |
| if (REG_P (dest) |
| || (MEM_P (dest) && cselib_record_memory)) |
| { |
| rtx src = sets[i].src; |
| if (cond) |
| src = gen_rtx_IF_THEN_ELSE (GET_MODE (dest), cond, src, dest); |
| sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1, VOIDmode); |
| if (MEM_P (dest)) |
| { |
| machine_mode address_mode = get_address_mode (dest); |
| |
| sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), |
| address_mode, 1, |
| GET_MODE (dest)); |
| } |
| else |
| sets[i].dest_addr_elt = 0; |
| } |
| |
| /* Improve handling of STRICT_LOW_PART if the current value is known |
| to be const0_rtx, then the low bits will be set to dest and higher |
| bits will remain zero. Used in code like: |
| |
| {di:SI=0;clobber flags:CC;} |
| flags:CCNO=cmp(bx:SI,0) |
| strict_low_part(di:QI)=flags:CCNO<=0 |
| |
| where we can note both that di:QI=flags:CCNO<=0 and |
| also that because di:SI is known to be 0 and strict_low_part(di:QI) |
| preserves the upper bits that di:SI=zero_extend(flags:CCNO<=0). */ |
| scalar_int_mode mode; |
| if (dest != orig |
| && cselib_record_sets_hook |
| && REG_P (dest) |
| && HARD_REGISTER_P (dest) |
| && sets[i].src_elt |
| && is_a <scalar_int_mode> (GET_MODE (dest), &mode) |
| && n_sets + n_strict_low_parts < MAX_SETS) |
| { |
| opt_scalar_int_mode wider_mode_iter; |
| FOR_EACH_WIDER_MODE (wider_mode_iter, mode) |
| { |
| scalar_int_mode wider_mode = wider_mode_iter.require (); |
| if (GET_MODE_PRECISION (wider_mode) > BITS_PER_WORD) |
| break; |
| |
| rtx reg = gen_lowpart (wider_mode, dest); |
| if (!REG_P (reg)) |
| break; |
| |
| cselib_val *v = cselib_lookup (reg, wider_mode, 0, VOIDmode); |
| if (!v) |
| continue; |
| |
| struct elt_loc_list *l; |
| for (l = v->locs; l; l = l->next) |
| if (l->loc == const0_rtx) |
| break; |
| |
| if (!l) |
| continue; |
| |
| sets[n_sets + n_strict_low_parts].dest = reg; |
| sets[n_sets + n_strict_low_parts].src = dest; |
| sets[n_sets + n_strict_low_parts++].src_elt = sets[i].src_elt; |
| break; |
| } |
| } |
| } |
| |
| if (cselib_record_sets_hook) |
| cselib_record_sets_hook (insn, sets, n_sets); |
| |
| /* Invalidate all locations written by this insn. Note that the elts we |
| looked up in the previous loop aren't affected, just some of their |
| locations may go away. */ |
| note_pattern_stores (body, cselib_invalidate_rtx_note_stores, NULL); |
| |
| for (i = n_sets_before_autoinc; i < n_sets; i++) |
| cselib_invalidate_rtx (sets[i].dest); |
| |
| /* If this is an asm, look for duplicate sets. This can happen when the |
| user uses the same value as an output multiple times. This is valid |
| if the outputs are not actually used thereafter. Treat this case as |
| if the value isn't actually set. We do this by smashing the destination |
| to pc_rtx, so that we won't record the value later. */ |
| if (n_sets >= 2 && asm_noperands (body) >= 0) |
| { |
| for (i = 0; i < n_sets; i++) |
| { |
| rtx dest = sets[i].dest; |
| if (REG_P (dest) || MEM_P (dest)) |
| { |
| int j; |
| for (j = i + 1; j < n_sets; j++) |
| if (rtx_equal_p (dest, sets[j].dest)) |
| { |
| sets[i].dest = pc_rtx; |
| sets[j].dest = pc_rtx; |
| } |
| } |
| } |
| } |
| |
| /* Now enter the equivalences in our tables. */ |
| for (i = 0; i < n_sets; i++) |
| { |
| rtx dest = sets[i].dest; |
| if (REG_P (dest) |
| || (MEM_P (dest) && cselib_record_memory)) |
| cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt); |
| } |
| |
| /* And deal with STRICT_LOW_PART. */ |
| for (i = 0; i < n_strict_low_parts; i++) |
| { |
| if (! PRESERVED_VALUE_P (sets[n_sets + i].src_elt->val_rtx)) |
| continue; |
| machine_mode dest_mode = GET_MODE (sets[n_sets + i].dest); |
| cselib_val *v |
| = cselib_lookup (sets[n_sets + i].dest, dest_mode, 1, VOIDmode); |
| cselib_preserve_value (v); |
| rtx r = gen_rtx_ZERO_EXTEND (dest_mode, |
| sets[n_sets + i].src_elt->val_rtx); |
| cselib_add_permanent_equiv (v, r, insn); |
| } |
| } |
| |
| /* Return true if INSN in the prologue initializes hard_frame_pointer_rtx. */ |
| |
| bool |
| fp_setter_insn (rtx_insn *insn) |
| { |
| rtx expr, pat = NULL_RTX; |
| |
| if (!RTX_FRAME_RELATED_P (insn)) |
| return false; |
| |
| expr = find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX); |
| if (expr) |
| pat = XEXP (expr, 0); |
| if (!modified_in_p (hard_frame_pointer_rtx, pat ? pat : insn)) |
| return false; |
| |
| /* Don't return true for frame pointer restores in the epilogue. */ |
| if (find_reg_note (insn, REG_CFA_RESTORE, hard_frame_pointer_rtx)) |
| return false; |
| return true; |
| } |
| |
| /* V is one of the values in REG_VALUES (REGNO). Return true if it |
| would be invalidated by CALLEE_ABI. */ |
| |
| static bool |
| cselib_invalidated_by_call_p (const function_abi &callee_abi, |
| unsigned int regno, cselib_val *v) |
| { |
| machine_mode mode = GET_MODE (v->val_rtx); |
| if (mode == VOIDmode) |
| { |
| v = REG_VALUES (regno)->elt; |
| if (!v) |
| /* If we don't know what the mode of the constant value is, and we |
| don't know what mode the register was set in, conservatively |
| assume that the register is clobbered. The value's going to be |
| essentially useless in this case anyway. */ |
| return true; |
| mode = GET_MODE (v->val_rtx); |
| } |
| return callee_abi.clobbers_reg_p (mode, regno); |
| } |
| |
| /* Record the effects of INSN. */ |
| |
| void |
| cselib_process_insn (rtx_insn *insn) |
| { |
| int i; |
| rtx x; |
| |
| cselib_current_insn = insn; |
| |
| /* Forget everything at a CODE_LABEL or a setjmp. */ |
| if ((LABEL_P (insn) |
| || (CALL_P (insn) |
| && find_reg_note (insn, REG_SETJMP, NULL))) |
| && !cselib_preserve_constants) |
| { |
| cselib_reset_table (next_uid); |
| cselib_current_insn = NULL; |
| return; |
| } |
| |
| if (! INSN_P (insn)) |
| { |
| cselib_current_insn = NULL; |
| return; |
| } |
| |
| /* If this is a call instruction, forget anything stored in a |
| call clobbered register, or, if this is not a const call, in |
| memory. */ |
| if (CALL_P (insn)) |
| { |
| function_abi callee_abi = insn_callee_abi (insn); |
| for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) |
| { |
| elt_list **l = ®_VALUES (i); |
| while (*l) |
| { |
| cselib_val *v = (*l)->elt; |
| if (v && cselib_invalidated_by_call_p (callee_abi, i, v)) |
| cselib_invalidate_regno_val (i, l); |
| else |
| l = &(*l)->next; |
| } |
| } |
| |
| /* Since it is not clear how cselib is going to be used, be |
| conservative here and treat looping pure or const functions |
| as if they were regular functions. */ |
| if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn) |
| || !(RTL_CONST_OR_PURE_CALL_P (insn))) |
| cselib_invalidate_mem (callmem); |
| else |
| /* For const/pure calls, invalidate any argument slots because |
| they are owned by the callee. */ |
| for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) |
| if (GET_CODE (XEXP (x, 0)) == USE |
| && MEM_P (XEXP (XEXP (x, 0), 0))) |
| cselib_invalidate_mem (XEXP (XEXP (x, 0), 0)); |
| } |
| |
| cselib_record_sets (insn); |
| |
| /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only |
| after we have processed the insn. */ |
| if (CALL_P (insn)) |
| { |
| for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1)) |
| if (GET_CODE (XEXP (x, 0)) == CLOBBER) |
| cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0)); |
| |
| /* Flush everything on setjmp. */ |
| if (cselib_preserve_constants |
| && find_reg_note (insn, REG_SETJMP, NULL)) |
| { |
| cselib_preserve_only_values (); |
| cselib_reset_table (next_uid); |
| } |
| } |
| |
| /* On setter of the hard frame pointer if frame_pointer_needed, |
| invalidate stack_pointer_rtx, so that sp and {,h}fp based |
| VALUEs are distinct. */ |
| if (reload_completed |
| && frame_pointer_needed |
| && fp_setter_insn (insn)) |
| cselib_invalidate_rtx (stack_pointer_rtx); |
| |
| cselib_current_insn = NULL; |
|