2034 lines
53 KiB
C
2034 lines
53 KiB
C
/* String length optimization
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Copyright (C) 2011 Free Software Foundation, Inc.
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Contributed by Jakub Jelinek <jakub@redhat.com>
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tree-flow.h"
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#include "tree-pass.h"
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#include "domwalk.h"
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#include "alloc-pool.h"
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#include "tree-ssa-propagate.h"
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#include "gimple-pretty-print.h"
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#include "params.h"
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#include "expr.h"
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/* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value
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is an index into strinfo vector, negative value stands for
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string length of a string literal (~strlen). */
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static VEC (int, heap) *ssa_ver_to_stridx;
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/* Number of currently active string indexes plus one. */
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static int max_stridx;
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/* String information record. */
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typedef struct strinfo_struct
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{
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/* String length of this string. */
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tree length;
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/* Any of the corresponding pointers for querying alias oracle. */
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tree ptr;
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/* Statement for delayed length computation. */
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gimple stmt;
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/* Pointer to '\0' if known, if NULL, it can be computed as
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ptr + length. */
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tree endptr;
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/* Reference count. Any changes to strinfo entry possibly shared
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with dominating basic blocks need unshare_strinfo first, except
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for dont_invalidate which affects only the immediately next
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maybe_invalidate. */
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int refcount;
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/* Copy of index. get_strinfo (si->idx) should return si; */
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int idx;
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/* These 3 fields are for chaining related string pointers together.
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E.g. for
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bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl;
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strcpy (c, d); e = c + dl;
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strinfo(a) -> strinfo(c) -> strinfo(e)
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All have ->first field equal to strinfo(a)->idx and are doubly
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chained through prev/next fields. The later strinfos are required
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to point into the same string with zero or more bytes after
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the previous pointer and all bytes in between the two pointers
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must be non-zero. Functions like strcpy or memcpy are supposed
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to adjust all previous strinfo lengths, but not following strinfo
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lengths (those are uncertain, usually invalidated during
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maybe_invalidate, except when the alias oracle knows better).
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Functions like strcat on the other side adjust the whole
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related strinfo chain.
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They are updated lazily, so to use the chain the same first fields
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and si->prev->next == si->idx needs to be verified. */
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int first;
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int next;
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int prev;
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/* A flag whether the string is known to be written in the current
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function. */
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bool writable;
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/* A flag for the next maybe_invalidate that this strinfo shouldn't
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be invalidated. Always cleared by maybe_invalidate. */
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bool dont_invalidate;
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} *strinfo;
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DEF_VEC_P(strinfo);
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DEF_VEC_ALLOC_P(strinfo,heap);
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/* Pool for allocating strinfo_struct entries. */
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static alloc_pool strinfo_pool;
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/* Vector mapping positive string indexes to strinfo, for the
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current basic block. The first pointer in the vector is special,
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it is either NULL, meaning the vector isn't shared, or it is
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a basic block pointer to the owner basic_block if shared.
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If some other bb wants to modify the vector, the vector needs
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to be unshared first, and only the owner bb is supposed to free it. */
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static VEC(strinfo, heap) *stridx_to_strinfo;
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/* One OFFSET->IDX mapping. */
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struct stridxlist
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{
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struct stridxlist *next;
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HOST_WIDE_INT offset;
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int idx;
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};
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/* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */
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struct decl_stridxlist_map
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{
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struct tree_map_base base;
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struct stridxlist list;
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};
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/* Hash table for mapping decls to a chained list of offset -> idx
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mappings. */
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static htab_t decl_to_stridxlist_htab;
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/* Obstack for struct stridxlist and struct decl_stridxlist_map. */
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static struct obstack stridx_obstack;
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/* Last memcpy statement if it could be adjusted if the trailing
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'\0' written is immediately overwritten, or
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*x = '\0' store that could be removed if it is immediately overwritten. */
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struct laststmt_struct
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{
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gimple stmt;
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tree len;
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int stridx;
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} laststmt;
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/* Hash a from tree in a decl_stridxlist_map. */
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static unsigned int
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decl_to_stridxlist_hash (const void *item)
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{
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return DECL_UID (((const struct decl_stridxlist_map *) item)->base.from);
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}
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/* Helper function for get_stridx. */
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static int
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get_addr_stridx (tree exp)
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{
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HOST_WIDE_INT off;
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struct decl_stridxlist_map ent, *e;
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struct stridxlist *list;
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tree base;
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if (decl_to_stridxlist_htab == NULL)
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return 0;
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base = get_addr_base_and_unit_offset (exp, &off);
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if (base == NULL || !DECL_P (base))
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return 0;
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ent.base.from = base;
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e = (struct decl_stridxlist_map *)
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htab_find_with_hash (decl_to_stridxlist_htab, &ent, DECL_UID (base));
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if (e == NULL)
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return 0;
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list = &e->list;
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do
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{
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if (list->offset == off)
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return list->idx;
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list = list->next;
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}
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while (list);
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return 0;
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}
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/* Return string index for EXP. */
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static int
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get_stridx (tree exp)
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{
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tree s, o;
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if (TREE_CODE (exp) == SSA_NAME)
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return VEC_index (int, ssa_ver_to_stridx, SSA_NAME_VERSION (exp));
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if (TREE_CODE (exp) == ADDR_EXPR)
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{
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int idx = get_addr_stridx (TREE_OPERAND (exp, 0));
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if (idx != 0)
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return idx;
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}
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s = string_constant (exp, &o);
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if (s != NULL_TREE
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&& (o == NULL_TREE || host_integerp (o, 0))
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&& TREE_STRING_LENGTH (s) > 0)
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{
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HOST_WIDE_INT offset = o ? tree_low_cst (o, 0) : 0;
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const char *p = TREE_STRING_POINTER (s);
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int max = TREE_STRING_LENGTH (s) - 1;
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if (p[max] == '\0' && offset >= 0 && offset <= max)
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return ~(int) strlen (p + offset);
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}
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return 0;
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}
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/* Return true if strinfo vector is shared with the immediate dominator. */
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static inline bool
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strinfo_shared (void)
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{
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return VEC_length (strinfo, stridx_to_strinfo)
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&& VEC_index (strinfo, stridx_to_strinfo, 0) != NULL;
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}
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/* Unshare strinfo vector that is shared with the immediate dominator. */
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static void
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unshare_strinfo_vec (void)
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{
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strinfo si;
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unsigned int i = 0;
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gcc_assert (strinfo_shared ());
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stridx_to_strinfo = VEC_copy (strinfo, heap, stridx_to_strinfo);
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for (i = 1; VEC_iterate (strinfo, stridx_to_strinfo, i, si); ++i)
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if (si != NULL)
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si->refcount++;
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VEC_replace (strinfo, stridx_to_strinfo, 0, NULL);
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}
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/* Attempt to create a string index for exp, ADDR_EXPR's operand.
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Return a pointer to the location where the string index can
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be stored (if 0) or is stored, or NULL if this can't be tracked. */
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static int *
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addr_stridxptr (tree exp)
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{
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void **slot;
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struct decl_stridxlist_map ent;
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struct stridxlist *list;
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HOST_WIDE_INT off;
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tree base = get_addr_base_and_unit_offset (exp, &off);
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if (base == NULL_TREE || !DECL_P (base))
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return NULL;
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if (decl_to_stridxlist_htab == NULL)
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{
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decl_to_stridxlist_htab
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= htab_create (64, decl_to_stridxlist_hash, tree_map_base_eq, NULL);
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gcc_obstack_init (&stridx_obstack);
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}
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ent.base.from = base;
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slot = htab_find_slot_with_hash (decl_to_stridxlist_htab, &ent,
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DECL_UID (base), INSERT);
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if (*slot)
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{
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int i;
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list = &((struct decl_stridxlist_map *)*slot)->list;
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for (i = 0; i < 16; i++)
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{
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if (list->offset == off)
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return &list->idx;
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if (list->next == NULL)
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break;
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}
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if (i == 16)
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return NULL;
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list->next = XOBNEW (&stridx_obstack, struct stridxlist);
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list = list->next;
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}
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else
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{
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struct decl_stridxlist_map *e
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= XOBNEW (&stridx_obstack, struct decl_stridxlist_map);
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e->base.from = base;
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*slot = (void *) e;
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list = &e->list;
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}
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list->next = NULL;
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list->offset = off;
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list->idx = 0;
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return &list->idx;
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}
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/* Create a new string index, or return 0 if reached limit. */
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static int
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new_stridx (tree exp)
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{
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int idx;
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if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS))
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return 0;
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if (TREE_CODE (exp) == SSA_NAME)
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{
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if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp))
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return 0;
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idx = max_stridx++;
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VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (exp), idx);
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return idx;
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}
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if (TREE_CODE (exp) == ADDR_EXPR)
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{
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int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0));
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if (pidx != NULL)
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{
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gcc_assert (*pidx == 0);
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*pidx = max_stridx++;
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return *pidx;
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}
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}
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return 0;
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}
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/* Like new_stridx, but for ADDR_EXPR's operand instead. */
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static int
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new_addr_stridx (tree exp)
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{
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int *pidx;
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if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS))
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return 0;
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pidx = addr_stridxptr (exp);
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if (pidx != NULL)
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{
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gcc_assert (*pidx == 0);
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*pidx = max_stridx++;
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return *pidx;
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}
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return 0;
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}
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/* Create a new strinfo. */
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static strinfo
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new_strinfo (tree ptr, int idx, tree length)
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{
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strinfo si = (strinfo) pool_alloc (strinfo_pool);
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si->length = length;
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si->ptr = ptr;
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si->stmt = NULL;
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si->endptr = NULL_TREE;
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si->refcount = 1;
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si->idx = idx;
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si->first = 0;
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si->prev = 0;
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si->next = 0;
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si->writable = false;
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si->dont_invalidate = false;
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return si;
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}
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/* Decrease strinfo refcount and free it if not referenced anymore. */
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static inline void
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free_strinfo (strinfo si)
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{
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if (si && --si->refcount == 0)
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pool_free (strinfo_pool, si);
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}
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/* Return strinfo vector entry IDX. */
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static inline strinfo
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get_strinfo (int idx)
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{
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if (VEC_length (strinfo, stridx_to_strinfo) <= (unsigned int) idx)
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return NULL;
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return VEC_index (strinfo, stridx_to_strinfo, idx);
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}
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/* Set strinfo in the vector entry IDX to SI. */
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static inline void
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set_strinfo (int idx, strinfo si)
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{
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if (VEC_length (strinfo, stridx_to_strinfo) && VEC_index (strinfo, stridx_to_strinfo, 0))
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unshare_strinfo_vec ();
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if (VEC_length (strinfo, stridx_to_strinfo) <= (unsigned int) idx)
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VEC_safe_grow_cleared (strinfo, heap, stridx_to_strinfo, idx + 1);
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VEC_replace (strinfo, stridx_to_strinfo, idx, si);
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}
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/* Return string length, or NULL if it can't be computed. */
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static tree
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get_string_length (strinfo si)
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{
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if (si->length)
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return si->length;
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if (si->stmt)
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{
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gimple stmt = si->stmt, lenstmt;
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tree callee, lhs, fn, tem;
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location_t loc;
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gimple_stmt_iterator gsi;
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gcc_assert (is_gimple_call (stmt));
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callee = gimple_call_fndecl (stmt);
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gcc_assert (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL);
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lhs = gimple_call_lhs (stmt);
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gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY));
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/* unshare_strinfo is intentionally not called here. The (delayed)
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transformation of strcpy or strcat into stpcpy is done at the place
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of the former strcpy/strcat call and so can affect all the strinfos
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with the same stmt. If they were unshared before and transformation
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has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should
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just compute the right length. */
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switch (DECL_FUNCTION_CODE (callee))
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{
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case BUILT_IN_STRCAT:
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case BUILT_IN_STRCAT_CHK:
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gsi = gsi_for_stmt (stmt);
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fn = builtin_decl_implicit (BUILT_IN_STRLEN);
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gcc_assert (lhs == NULL_TREE);
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tem = unshare_expr (gimple_call_arg (stmt, 0));
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lenstmt = gimple_build_call (fn, 1, tem);
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lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt);
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gimple_call_set_lhs (lenstmt, lhs);
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gimple_set_vuse (lenstmt, gimple_vuse (stmt));
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gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT);
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tem = gimple_call_arg (stmt, 0);
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if (!ptrofftype_p (TREE_TYPE (lhs)))
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{
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lhs = convert_to_ptrofftype (lhs);
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lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE,
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true, GSI_SAME_STMT);
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}
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lenstmt
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= gimple_build_assign_with_ops
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(POINTER_PLUS_EXPR,
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make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0)), NULL),
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tem, lhs);
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gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT);
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gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt));
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lhs = NULL_TREE;
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/* FALLTHRU */
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case BUILT_IN_STRCPY:
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case BUILT_IN_STRCPY_CHK:
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if (gimple_call_num_args (stmt) == 2)
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fn = builtin_decl_implicit (BUILT_IN_STPCPY);
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else
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fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK);
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gcc_assert (lhs == NULL_TREE);
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if (dump_file && (dump_flags & TDF_DETAILS) != 0)
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{
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fprintf (dump_file, "Optimizing: ");
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print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
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}
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gimple_call_set_fndecl (stmt, fn);
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lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt);
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gimple_call_set_lhs (stmt, lhs);
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update_stmt (stmt);
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if (dump_file && (dump_flags & TDF_DETAILS) != 0)
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{
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fprintf (dump_file, "into: ");
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print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
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}
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/* FALLTHRU */
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case BUILT_IN_STPCPY:
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case BUILT_IN_STPCPY_CHK:
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gcc_assert (lhs != NULL_TREE);
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loc = gimple_location (stmt);
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si->endptr = lhs;
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si->stmt = NULL;
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lhs = fold_convert_loc (loc, size_type_node, lhs);
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si->length = fold_convert_loc (loc, size_type_node, si->ptr);
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si->length = fold_build2_loc (loc, MINUS_EXPR, size_type_node,
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lhs, si->length);
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break;
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default:
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gcc_unreachable ();
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break;
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}
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}
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return si->length;
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}
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|
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/* Invalidate string length information for strings whose length
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might change due to stores in stmt. */
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|
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static bool
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maybe_invalidate (gimple stmt)
|
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{
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strinfo si;
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unsigned int i;
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bool nonempty = false;
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for (i = 1; VEC_iterate (strinfo, stridx_to_strinfo, i, si); ++i)
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if (si != NULL)
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{
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if (!si->dont_invalidate)
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{
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ao_ref r;
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ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE);
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if (stmt_may_clobber_ref_p_1 (stmt, &r))
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{
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set_strinfo (i, NULL);
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free_strinfo (si);
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|
continue;
|
|
}
|
|
}
|
|
si->dont_invalidate = false;
|
|
nonempty = true;
|
|
}
|
|
return nonempty;
|
|
}
|
|
|
|
/* Unshare strinfo record SI, if it has recount > 1 or
|
|
if stridx_to_strinfo vector is shared with some other
|
|
bbs. */
|
|
|
|
static strinfo
|
|
unshare_strinfo (strinfo si)
|
|
{
|
|
strinfo nsi;
|
|
|
|
if (si->refcount == 1 && !strinfo_shared ())
|
|
return si;
|
|
|
|
nsi = new_strinfo (si->ptr, si->idx, si->length);
|
|
nsi->stmt = si->stmt;
|
|
nsi->endptr = si->endptr;
|
|
nsi->first = si->first;
|
|
nsi->prev = si->prev;
|
|
nsi->next = si->next;
|
|
nsi->writable = si->writable;
|
|
set_strinfo (si->idx, nsi);
|
|
free_strinfo (si);
|
|
return nsi;
|
|
}
|
|
|
|
/* Return first strinfo in the related strinfo chain
|
|
if all strinfos in between belong to the chain, otherwise
|
|
NULL. */
|
|
|
|
static strinfo
|
|
verify_related_strinfos (strinfo origsi)
|
|
{
|
|
strinfo si = origsi, psi;
|
|
|
|
if (origsi->first == 0)
|
|
return NULL;
|
|
for (; si->prev; si = psi)
|
|
{
|
|
if (si->first != origsi->first)
|
|
return NULL;
|
|
psi = get_strinfo (si->prev);
|
|
if (psi == NULL)
|
|
return NULL;
|
|
if (psi->next != si->idx)
|
|
return NULL;
|
|
}
|
|
if (si->idx != si->first)
|
|
return NULL;
|
|
return si;
|
|
}
|
|
|
|
/* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points
|
|
to a zero-length string and if possible chain it to a related strinfo
|
|
chain whose part is or might be CHAINSI. */
|
|
|
|
static strinfo
|
|
zero_length_string (tree ptr, strinfo chainsi)
|
|
{
|
|
strinfo si;
|
|
int idx;
|
|
gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME
|
|
&& get_stridx (ptr) == 0);
|
|
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr))
|
|
return NULL;
|
|
if (chainsi != NULL)
|
|
{
|
|
si = verify_related_strinfos (chainsi);
|
|
if (si)
|
|
{
|
|
chainsi = si;
|
|
for (; chainsi->next; chainsi = si)
|
|
{
|
|
if (chainsi->endptr == NULL_TREE)
|
|
{
|
|
chainsi = unshare_strinfo (chainsi);
|
|
chainsi->endptr = ptr;
|
|
}
|
|
si = get_strinfo (chainsi->next);
|
|
if (si == NULL
|
|
|| si->first != chainsi->first
|
|
|| si->prev != chainsi->idx)
|
|
break;
|
|
}
|
|
gcc_assert (chainsi->length || chainsi->stmt);
|
|
if (chainsi->endptr == NULL_TREE)
|
|
{
|
|
chainsi = unshare_strinfo (chainsi);
|
|
chainsi->endptr = ptr;
|
|
}
|
|
if (chainsi->length && integer_zerop (chainsi->length))
|
|
{
|
|
if (chainsi->next)
|
|
{
|
|
chainsi = unshare_strinfo (chainsi);
|
|
chainsi->next = 0;
|
|
}
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (ptr),
|
|
chainsi->idx);
|
|
return chainsi;
|
|
}
|
|
}
|
|
else if (chainsi->first || chainsi->prev || chainsi->next)
|
|
{
|
|
chainsi = unshare_strinfo (chainsi);
|
|
chainsi->first = 0;
|
|
chainsi->prev = 0;
|
|
chainsi->next = 0;
|
|
}
|
|
}
|
|
idx = new_stridx (ptr);
|
|
if (idx == 0)
|
|
return NULL;
|
|
si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0));
|
|
set_strinfo (idx, si);
|
|
si->endptr = ptr;
|
|
if (chainsi != NULL)
|
|
{
|
|
chainsi = unshare_strinfo (chainsi);
|
|
if (chainsi->first == 0)
|
|
chainsi->first = chainsi->idx;
|
|
chainsi->next = idx;
|
|
if (chainsi->endptr == NULL_TREE)
|
|
chainsi->endptr = ptr;
|
|
si->prev = chainsi->idx;
|
|
si->first = chainsi->first;
|
|
si->writable = chainsi->writable;
|
|
}
|
|
return si;
|
|
}
|
|
|
|
/* For strinfo ORIGSI whose length has been just updated
|
|
update also related strinfo lengths (add ADJ to each,
|
|
but don't adjust ORIGSI). */
|
|
|
|
static void
|
|
adjust_related_strinfos (location_t loc, strinfo origsi, tree adj)
|
|
{
|
|
strinfo si = verify_related_strinfos (origsi);
|
|
|
|
if (si == NULL)
|
|
return;
|
|
|
|
while (1)
|
|
{
|
|
strinfo nsi;
|
|
|
|
if (si != origsi)
|
|
{
|
|
tree tem;
|
|
|
|
si = unshare_strinfo (si);
|
|
if (si->length)
|
|
{
|
|
tem = fold_convert_loc (loc, TREE_TYPE (si->length), adj);
|
|
si->length = fold_build2_loc (loc, PLUS_EXPR,
|
|
TREE_TYPE (si->length), si->length,
|
|
tem);
|
|
}
|
|
else if (si->stmt != NULL)
|
|
/* Delayed length computation is unaffected. */
|
|
;
|
|
else
|
|
gcc_unreachable ();
|
|
|
|
si->endptr = NULL_TREE;
|
|
si->dont_invalidate = true;
|
|
}
|
|
if (si->next == 0)
|
|
return;
|
|
nsi = get_strinfo (si->next);
|
|
if (nsi == NULL
|
|
|| nsi->first != si->first
|
|
|| nsi->prev != si->idx)
|
|
return;
|
|
si = nsi;
|
|
}
|
|
}
|
|
|
|
/* Find if there are other SSA_NAME pointers equal to PTR
|
|
for which we don't track their string lengths yet. If so, use
|
|
IDX for them. */
|
|
|
|
static void
|
|
find_equal_ptrs (tree ptr, int idx)
|
|
{
|
|
if (TREE_CODE (ptr) != SSA_NAME)
|
|
return;
|
|
while (1)
|
|
{
|
|
gimple stmt = SSA_NAME_DEF_STMT (ptr);
|
|
if (!is_gimple_assign (stmt))
|
|
return;
|
|
ptr = gimple_assign_rhs1 (stmt);
|
|
switch (gimple_assign_rhs_code (stmt))
|
|
{
|
|
case SSA_NAME:
|
|
break;
|
|
CASE_CONVERT:
|
|
if (!POINTER_TYPE_P (TREE_TYPE (ptr)))
|
|
return;
|
|
if (TREE_CODE (ptr) == SSA_NAME)
|
|
break;
|
|
if (TREE_CODE (ptr) != ADDR_EXPR)
|
|
return;
|
|
/* FALLTHRU */
|
|
case ADDR_EXPR:
|
|
{
|
|
int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0));
|
|
if (pidx != NULL && *pidx == 0)
|
|
*pidx = idx;
|
|
return;
|
|
}
|
|
default:
|
|
return;
|
|
}
|
|
|
|
/* We might find an endptr created in this pass. Grow the
|
|
vector in that case. */
|
|
if (VEC_length (int, ssa_ver_to_stridx) <= SSA_NAME_VERSION (ptr))
|
|
VEC_safe_grow_cleared (int, heap, ssa_ver_to_stridx, num_ssa_names);
|
|
|
|
if (VEC_index (int, ssa_ver_to_stridx, SSA_NAME_VERSION (ptr)) != 0)
|
|
return;
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (ptr), idx);
|
|
}
|
|
}
|
|
|
|
/* If the last .MEM setter statement before STMT is
|
|
memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT
|
|
and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to
|
|
just memcpy (x, y, strlen (y)). SI must be the zero length
|
|
strinfo. */
|
|
|
|
static void
|
|
adjust_last_stmt (strinfo si, gimple stmt, bool is_strcat)
|
|
{
|
|
tree vuse, callee, len;
|
|
struct laststmt_struct last = laststmt;
|
|
strinfo lastsi, firstsi;
|
|
|
|
laststmt.stmt = NULL;
|
|
laststmt.len = NULL_TREE;
|
|
laststmt.stridx = 0;
|
|
|
|
if (last.stmt == NULL)
|
|
return;
|
|
|
|
vuse = gimple_vuse (stmt);
|
|
if (vuse == NULL_TREE
|
|
|| SSA_NAME_DEF_STMT (vuse) != last.stmt
|
|
|| !has_single_use (vuse))
|
|
return;
|
|
|
|
gcc_assert (last.stridx > 0);
|
|
lastsi = get_strinfo (last.stridx);
|
|
if (lastsi == NULL)
|
|
return;
|
|
|
|
if (lastsi != si)
|
|
{
|
|
if (lastsi->first == 0 || lastsi->first != si->first)
|
|
return;
|
|
|
|
firstsi = verify_related_strinfos (si);
|
|
if (firstsi == NULL)
|
|
return;
|
|
while (firstsi != lastsi)
|
|
{
|
|
strinfo nextsi;
|
|
if (firstsi->next == 0)
|
|
return;
|
|
nextsi = get_strinfo (firstsi->next);
|
|
if (nextsi == NULL
|
|
|| nextsi->prev != firstsi->idx
|
|
|| nextsi->first != si->first)
|
|
return;
|
|
firstsi = nextsi;
|
|
}
|
|
}
|
|
|
|
if (!is_strcat)
|
|
{
|
|
if (si->length == NULL_TREE || !integer_zerop (si->length))
|
|
return;
|
|
}
|
|
|
|
if (is_gimple_assign (last.stmt))
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
|
|
if (!integer_zerop (gimple_assign_rhs1 (last.stmt)))
|
|
return;
|
|
if (stmt_could_throw_p (last.stmt))
|
|
return;
|
|
gsi = gsi_for_stmt (last.stmt);
|
|
unlink_stmt_vdef (last.stmt);
|
|
release_defs (last.stmt);
|
|
gsi_remove (&gsi, true);
|
|
return;
|
|
}
|
|
|
|
if (!is_gimple_call (last.stmt))
|
|
return;
|
|
callee = gimple_call_fndecl (last.stmt);
|
|
if (callee == NULL_TREE || DECL_BUILT_IN_CLASS (callee) != BUILT_IN_NORMAL)
|
|
return;
|
|
|
|
switch (DECL_FUNCTION_CODE (callee))
|
|
{
|
|
case BUILT_IN_MEMCPY:
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
break;
|
|
default:
|
|
return;
|
|
}
|
|
|
|
len = gimple_call_arg (last.stmt, 2);
|
|
if (host_integerp (len, 1))
|
|
{
|
|
if (!host_integerp (last.len, 1)
|
|
|| integer_zerop (len)
|
|
|| (unsigned HOST_WIDE_INT) tree_low_cst (len, 1)
|
|
!= (unsigned HOST_WIDE_INT) tree_low_cst (last.len, 1) + 1)
|
|
return;
|
|
/* Don't adjust the length if it is divisible by 4, it is more efficient
|
|
to store the extra '\0' in that case. */
|
|
if ((((unsigned HOST_WIDE_INT) tree_low_cst (len, 1)) & 3) == 0)
|
|
return;
|
|
}
|
|
else if (TREE_CODE (len) == SSA_NAME)
|
|
{
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (len);
|
|
if (!is_gimple_assign (def_stmt)
|
|
|| gimple_assign_rhs_code (def_stmt) != PLUS_EXPR
|
|
|| gimple_assign_rhs1 (def_stmt) != last.len
|
|
|| !integer_onep (gimple_assign_rhs2 (def_stmt)))
|
|
return;
|
|
}
|
|
else
|
|
return;
|
|
|
|
gimple_call_set_arg (last.stmt, 2, last.len);
|
|
update_stmt (last.stmt);
|
|
}
|
|
|
|
/* Handle a strlen call. If strlen of the argument is known, replace
|
|
the strlen call with the known value, otherwise remember that strlen
|
|
of the argument is stored in the lhs SSA_NAME. */
|
|
|
|
static void
|
|
handle_builtin_strlen (gimple_stmt_iterator *gsi)
|
|
{
|
|
int idx;
|
|
tree src;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
tree lhs = gimple_call_lhs (stmt);
|
|
|
|
if (lhs == NULL_TREE)
|
|
return;
|
|
|
|
src = gimple_call_arg (stmt, 0);
|
|
idx = get_stridx (src);
|
|
if (idx)
|
|
{
|
|
strinfo si = NULL;
|
|
tree rhs;
|
|
|
|
if (idx < 0)
|
|
rhs = build_int_cst (TREE_TYPE (lhs), ~idx);
|
|
else
|
|
{
|
|
rhs = NULL_TREE;
|
|
si = get_strinfo (idx);
|
|
if (si != NULL)
|
|
rhs = get_string_length (si);
|
|
}
|
|
if (rhs != NULL_TREE)
|
|
{
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "Optimizing: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
rhs = unshare_expr (rhs);
|
|
if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs)))
|
|
rhs = fold_convert_loc (gimple_location (stmt),
|
|
TREE_TYPE (lhs), rhs);
|
|
if (!update_call_from_tree (gsi, rhs))
|
|
gimplify_and_update_call_from_tree (gsi, rhs);
|
|
stmt = gsi_stmt (*gsi);
|
|
update_stmt (stmt);
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "into: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
if (si != NULL
|
|
&& TREE_CODE (si->length) != SSA_NAME
|
|
&& TREE_CODE (si->length) != INTEGER_CST
|
|
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
|
|
{
|
|
si = unshare_strinfo (si);
|
|
si->length = lhs;
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
|
|
return;
|
|
if (idx == 0)
|
|
idx = new_stridx (src);
|
|
else if (get_strinfo (idx) != NULL)
|
|
return;
|
|
if (idx)
|
|
{
|
|
strinfo si = new_strinfo (src, idx, lhs);
|
|
set_strinfo (idx, si);
|
|
find_equal_ptrs (src, idx);
|
|
}
|
|
}
|
|
|
|
/* Handle a strchr call. If strlen of the first argument is known, replace
|
|
the strchr (x, 0) call with the endptr or x + strlen, otherwise remember
|
|
that lhs of the call is endptr and strlen of the argument is endptr - x. */
|
|
|
|
static void
|
|
handle_builtin_strchr (gimple_stmt_iterator *gsi)
|
|
{
|
|
int idx;
|
|
tree src;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
tree lhs = gimple_call_lhs (stmt);
|
|
|
|
if (lhs == NULL_TREE)
|
|
return;
|
|
|
|
if (!integer_zerop (gimple_call_arg (stmt, 1)))
|
|
return;
|
|
|
|
src = gimple_call_arg (stmt, 0);
|
|
idx = get_stridx (src);
|
|
if (idx)
|
|
{
|
|
strinfo si = NULL;
|
|
tree rhs;
|
|
|
|
if (idx < 0)
|
|
rhs = build_int_cst (size_type_node, ~idx);
|
|
else
|
|
{
|
|
rhs = NULL_TREE;
|
|
si = get_strinfo (idx);
|
|
if (si != NULL)
|
|
rhs = get_string_length (si);
|
|
}
|
|
if (rhs != NULL_TREE)
|
|
{
|
|
location_t loc = gimple_location (stmt);
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "Optimizing: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
if (si != NULL && si->endptr != NULL_TREE)
|
|
{
|
|
rhs = unshare_expr (si->endptr);
|
|
if (!useless_type_conversion_p (TREE_TYPE (lhs),
|
|
TREE_TYPE (rhs)))
|
|
rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
|
|
}
|
|
else
|
|
{
|
|
rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs));
|
|
rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR,
|
|
TREE_TYPE (src), src, rhs);
|
|
if (!useless_type_conversion_p (TREE_TYPE (lhs),
|
|
TREE_TYPE (rhs)))
|
|
rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs);
|
|
}
|
|
if (!update_call_from_tree (gsi, rhs))
|
|
gimplify_and_update_call_from_tree (gsi, rhs);
|
|
stmt = gsi_stmt (*gsi);
|
|
update_stmt (stmt);
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "into: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
if (si != NULL
|
|
&& si->endptr == NULL_TREE
|
|
&& !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
|
|
{
|
|
si = unshare_strinfo (si);
|
|
si->endptr = lhs;
|
|
}
|
|
zero_length_string (lhs, si);
|
|
return;
|
|
}
|
|
}
|
|
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs))
|
|
return;
|
|
if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src))
|
|
{
|
|
if (idx == 0)
|
|
idx = new_stridx (src);
|
|
else if (get_strinfo (idx) != NULL)
|
|
{
|
|
zero_length_string (lhs, NULL);
|
|
return;
|
|
}
|
|
if (idx)
|
|
{
|
|
location_t loc = gimple_location (stmt);
|
|
tree lhsu = fold_convert_loc (loc, size_type_node, lhs);
|
|
tree srcu = fold_convert_loc (loc, size_type_node, src);
|
|
tree length = fold_build2_loc (loc, MINUS_EXPR,
|
|
size_type_node, lhsu, srcu);
|
|
strinfo si = new_strinfo (src, idx, length);
|
|
si->endptr = lhs;
|
|
set_strinfo (idx, si);
|
|
find_equal_ptrs (src, idx);
|
|
zero_length_string (lhs, si);
|
|
}
|
|
}
|
|
else
|
|
zero_length_string (lhs, NULL);
|
|
}
|
|
|
|
/* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call.
|
|
If strlen of the second argument is known, strlen of the first argument
|
|
is the same after this call. Furthermore, attempt to convert it to
|
|
memcpy. */
|
|
|
|
static void
|
|
handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi)
|
|
{
|
|
int idx, didx;
|
|
tree src, dst, srclen, len, lhs, args, type, fn, oldlen;
|
|
bool success;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
strinfo si, dsi, olddsi, zsi;
|
|
location_t loc;
|
|
|
|
src = gimple_call_arg (stmt, 1);
|
|
dst = gimple_call_arg (stmt, 0);
|
|
lhs = gimple_call_lhs (stmt);
|
|
idx = get_stridx (src);
|
|
si = NULL;
|
|
if (idx > 0)
|
|
si = get_strinfo (idx);
|
|
|
|
didx = get_stridx (dst);
|
|
olddsi = NULL;
|
|
oldlen = NULL_TREE;
|
|
if (didx > 0)
|
|
olddsi = get_strinfo (didx);
|
|
else if (didx < 0)
|
|
return;
|
|
|
|
if (olddsi != NULL)
|
|
adjust_last_stmt (olddsi, stmt, false);
|
|
|
|
srclen = NULL_TREE;
|
|
if (si != NULL)
|
|
srclen = get_string_length (si);
|
|
else if (idx < 0)
|
|
srclen = build_int_cst (size_type_node, ~idx);
|
|
|
|
loc = gimple_location (stmt);
|
|
if (srclen == NULL_TREE)
|
|
switch (bcode)
|
|
{
|
|
case BUILT_IN_STRCPY:
|
|
case BUILT_IN_STRCPY_CHK:
|
|
if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY))
|
|
return;
|
|
break;
|
|
case BUILT_IN_STPCPY:
|
|
case BUILT_IN_STPCPY_CHK:
|
|
if (lhs == NULL_TREE)
|
|
return;
|
|
else
|
|
{
|
|
tree lhsuint = fold_convert_loc (loc, size_type_node, lhs);
|
|
srclen = fold_convert_loc (loc, size_type_node, dst);
|
|
srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node,
|
|
lhsuint, srclen);
|
|
}
|
|
break;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
if (didx == 0)
|
|
{
|
|
didx = new_stridx (dst);
|
|
if (didx == 0)
|
|
return;
|
|
}
|
|
if (olddsi != NULL)
|
|
{
|
|
oldlen = olddsi->length;
|
|
dsi = unshare_strinfo (olddsi);
|
|
dsi->length = srclen;
|
|
/* Break the chain, so adjust_related_strinfo on later pointers in
|
|
the chain won't adjust this one anymore. */
|
|
dsi->next = 0;
|
|
dsi->stmt = NULL;
|
|
dsi->endptr = NULL_TREE;
|
|
}
|
|
else
|
|
{
|
|
dsi = new_strinfo (dst, didx, srclen);
|
|
set_strinfo (didx, dsi);
|
|
find_equal_ptrs (dst, didx);
|
|
}
|
|
dsi->writable = true;
|
|
dsi->dont_invalidate = true;
|
|
|
|
if (dsi->length == NULL_TREE)
|
|
{
|
|
strinfo chainsi;
|
|
|
|
/* If string length of src is unknown, use delayed length
|
|
computation. If string lenth of dst will be needed, it
|
|
can be computed by transforming this strcpy call into
|
|
stpcpy and subtracting dst from the return value. */
|
|
|
|
/* Look for earlier strings whose length could be determined if
|
|
this strcpy is turned into an stpcpy. */
|
|
|
|
if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL)
|
|
{
|
|
for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next))
|
|
{
|
|
/* When setting a stmt for delayed length computation
|
|
prevent all strinfos through dsi from being
|
|
invalidated. */
|
|
chainsi = unshare_strinfo (chainsi);
|
|
chainsi->stmt = stmt;
|
|
chainsi->length = NULL_TREE;
|
|
chainsi->endptr = NULL_TREE;
|
|
chainsi->dont_invalidate = true;
|
|
}
|
|
}
|
|
dsi->stmt = stmt;
|
|
return;
|
|
}
|
|
|
|
if (olddsi != NULL)
|
|
{
|
|
tree adj = NULL_TREE;
|
|
if (oldlen == NULL_TREE)
|
|
;
|
|
else if (integer_zerop (oldlen))
|
|
adj = srclen;
|
|
else if (TREE_CODE (oldlen) == INTEGER_CST
|
|
|| TREE_CODE (srclen) == INTEGER_CST)
|
|
adj = fold_build2_loc (loc, MINUS_EXPR,
|
|
TREE_TYPE (srclen), srclen,
|
|
fold_convert_loc (loc, TREE_TYPE (srclen),
|
|
oldlen));
|
|
if (adj != NULL_TREE)
|
|
adjust_related_strinfos (loc, dsi, adj);
|
|
else
|
|
dsi->prev = 0;
|
|
}
|
|
/* strcpy src may not overlap dst, so src doesn't need to be
|
|
invalidated either. */
|
|
if (si != NULL)
|
|
si->dont_invalidate = true;
|
|
|
|
fn = NULL_TREE;
|
|
zsi = NULL;
|
|
switch (bcode)
|
|
{
|
|
case BUILT_IN_STRCPY:
|
|
fn = builtin_decl_implicit (BUILT_IN_MEMCPY);
|
|
if (lhs)
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs), didx);
|
|
break;
|
|
case BUILT_IN_STRCPY_CHK:
|
|
fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK);
|
|
if (lhs)
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs), didx);
|
|
break;
|
|
case BUILT_IN_STPCPY:
|
|
/* This would need adjustment of the lhs (subtract one),
|
|
or detection that the trailing '\0' doesn't need to be
|
|
written, if it will be immediately overwritten.
|
|
fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */
|
|
if (lhs)
|
|
{
|
|
dsi->endptr = lhs;
|
|
zsi = zero_length_string (lhs, dsi);
|
|
}
|
|
break;
|
|
case BUILT_IN_STPCPY_CHK:
|
|
/* This would need adjustment of the lhs (subtract one),
|
|
or detection that the trailing '\0' doesn't need to be
|
|
written, if it will be immediately overwritten.
|
|
fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */
|
|
if (lhs)
|
|
{
|
|
dsi->endptr = lhs;
|
|
zsi = zero_length_string (lhs, dsi);
|
|
}
|
|
break;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
if (zsi != NULL)
|
|
zsi->dont_invalidate = true;
|
|
|
|
if (fn == NULL_TREE)
|
|
return;
|
|
|
|
args = TYPE_ARG_TYPES (TREE_TYPE (fn));
|
|
type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
|
|
|
|
len = fold_convert_loc (loc, type, unshare_expr (srclen));
|
|
len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1));
|
|
len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true,
|
|
GSI_SAME_STMT);
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "Optimizing: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
if (gimple_call_num_args (stmt) == 2)
|
|
success = update_gimple_call (gsi, fn, 3, dst, src, len);
|
|
else
|
|
success = update_gimple_call (gsi, fn, 4, dst, src, len,
|
|
gimple_call_arg (stmt, 2));
|
|
if (success)
|
|
{
|
|
stmt = gsi_stmt (*gsi);
|
|
update_stmt (stmt);
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "into: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
/* Allow adjust_last_stmt to decrease this memcpy's size. */
|
|
laststmt.stmt = stmt;
|
|
laststmt.len = srclen;
|
|
laststmt.stridx = dsi->idx;
|
|
}
|
|
else if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
fprintf (dump_file, "not possible.\n");
|
|
}
|
|
|
|
/* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call.
|
|
If strlen of the second argument is known and length of the third argument
|
|
is that plus one, strlen of the first argument is the same after this
|
|
call. */
|
|
|
|
static void
|
|
handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi)
|
|
{
|
|
int idx, didx;
|
|
tree src, dst, len, lhs, oldlen, newlen;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
strinfo si, dsi, olddsi;
|
|
|
|
len = gimple_call_arg (stmt, 2);
|
|
src = gimple_call_arg (stmt, 1);
|
|
dst = gimple_call_arg (stmt, 0);
|
|
idx = get_stridx (src);
|
|
if (idx == 0)
|
|
return;
|
|
|
|
didx = get_stridx (dst);
|
|
olddsi = NULL;
|
|
if (didx > 0)
|
|
olddsi = get_strinfo (didx);
|
|
else if (didx < 0)
|
|
return;
|
|
|
|
if (olddsi != NULL
|
|
&& host_integerp (len, 1)
|
|
&& !integer_zerop (len))
|
|
adjust_last_stmt (olddsi, stmt, false);
|
|
|
|
if (idx > 0)
|
|
{
|
|
gimple def_stmt;
|
|
|
|
/* Handle memcpy (x, y, l) where l is strlen (y) + 1. */
|
|
si = get_strinfo (idx);
|
|
if (si == NULL || si->length == NULL_TREE)
|
|
return;
|
|
if (TREE_CODE (len) != SSA_NAME)
|
|
return;
|
|
def_stmt = SSA_NAME_DEF_STMT (len);
|
|
if (!is_gimple_assign (def_stmt)
|
|
|| gimple_assign_rhs_code (def_stmt) != PLUS_EXPR
|
|
|| gimple_assign_rhs1 (def_stmt) != si->length
|
|
|| !integer_onep (gimple_assign_rhs2 (def_stmt)))
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
si = NULL;
|
|
/* Handle memcpy (x, "abcd", 5) or
|
|
memcpy (x, "abc\0uvw", 7). */
|
|
if (!host_integerp (len, 1)
|
|
|| (unsigned HOST_WIDE_INT) tree_low_cst (len, 1)
|
|
<= (unsigned HOST_WIDE_INT) ~idx)
|
|
return;
|
|
}
|
|
|
|
if (olddsi != NULL && TREE_CODE (len) == SSA_NAME)
|
|
adjust_last_stmt (olddsi, stmt, false);
|
|
|
|
if (didx == 0)
|
|
{
|
|
didx = new_stridx (dst);
|
|
if (didx == 0)
|
|
return;
|
|
}
|
|
if (si != NULL)
|
|
newlen = si->length;
|
|
else
|
|
newlen = build_int_cst (size_type_node, ~idx);
|
|
oldlen = NULL_TREE;
|
|
if (olddsi != NULL)
|
|
{
|
|
dsi = unshare_strinfo (olddsi);
|
|
oldlen = olddsi->length;
|
|
dsi->length = newlen;
|
|
/* Break the chain, so adjust_related_strinfo on later pointers in
|
|
the chain won't adjust this one anymore. */
|
|
dsi->next = 0;
|
|
dsi->stmt = NULL;
|
|
dsi->endptr = NULL_TREE;
|
|
}
|
|
else
|
|
{
|
|
dsi = new_strinfo (dst, didx, newlen);
|
|
set_strinfo (didx, dsi);
|
|
find_equal_ptrs (dst, didx);
|
|
}
|
|
dsi->writable = true;
|
|
dsi->dont_invalidate = true;
|
|
if (olddsi != NULL)
|
|
{
|
|
tree adj = NULL_TREE;
|
|
location_t loc = gimple_location (stmt);
|
|
if (oldlen == NULL_TREE)
|
|
;
|
|
else if (integer_zerop (oldlen))
|
|
adj = dsi->length;
|
|
else if (TREE_CODE (oldlen) == INTEGER_CST
|
|
|| TREE_CODE (dsi->length) == INTEGER_CST)
|
|
adj = fold_build2_loc (loc, MINUS_EXPR,
|
|
TREE_TYPE (dsi->length), dsi->length,
|
|
fold_convert_loc (loc, TREE_TYPE (dsi->length),
|
|
oldlen));
|
|
if (adj != NULL_TREE)
|
|
adjust_related_strinfos (loc, dsi, adj);
|
|
else
|
|
dsi->prev = 0;
|
|
}
|
|
/* memcpy src may not overlap dst, so src doesn't need to be
|
|
invalidated either. */
|
|
if (si != NULL)
|
|
si->dont_invalidate = true;
|
|
|
|
lhs = gimple_call_lhs (stmt);
|
|
switch (bcode)
|
|
{
|
|
case BUILT_IN_MEMCPY:
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
/* Allow adjust_last_stmt to decrease this memcpy's size. */
|
|
laststmt.stmt = stmt;
|
|
laststmt.len = dsi->length;
|
|
laststmt.stridx = dsi->idx;
|
|
if (lhs)
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs), didx);
|
|
break;
|
|
case BUILT_IN_MEMPCPY:
|
|
case BUILT_IN_MEMPCPY_CHK:
|
|
break;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
/* Handle a strcat-like ({strcat,__strcat_chk}) call.
|
|
If strlen of the second argument is known, strlen of the first argument
|
|
is increased by the length of the second argument. Furthermore, attempt
|
|
to convert it to memcpy/strcpy if the length of the first argument
|
|
is known. */
|
|
|
|
static void
|
|
handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi)
|
|
{
|
|
int idx, didx;
|
|
tree src, dst, srclen, dstlen, len, lhs, args, type, fn, objsz, endptr;
|
|
bool success;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
strinfo si, dsi;
|
|
location_t loc;
|
|
|
|
src = gimple_call_arg (stmt, 1);
|
|
dst = gimple_call_arg (stmt, 0);
|
|
lhs = gimple_call_lhs (stmt);
|
|
|
|
didx = get_stridx (dst);
|
|
if (didx < 0)
|
|
return;
|
|
|
|
dsi = NULL;
|
|
if (didx > 0)
|
|
dsi = get_strinfo (didx);
|
|
if (dsi == NULL || get_string_length (dsi) == NULL_TREE)
|
|
{
|
|
/* strcat (p, q) can be transformed into
|
|
tmp = p + strlen (p); endptr = strpcpy (tmp, q);
|
|
with length endptr - p if we need to compute the length
|
|
later on. Don't do this transformation if we don't need
|
|
it. */
|
|
if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE)
|
|
{
|
|
if (didx == 0)
|
|
{
|
|
didx = new_stridx (dst);
|
|
if (didx == 0)
|
|
return;
|
|
}
|
|
if (dsi == NULL)
|
|
{
|
|
dsi = new_strinfo (dst, didx, NULL_TREE);
|
|
set_strinfo (didx, dsi);
|
|
find_equal_ptrs (dst, didx);
|
|
}
|
|
else
|
|
{
|
|
dsi = unshare_strinfo (dsi);
|
|
dsi->length = NULL_TREE;
|
|
dsi->next = 0;
|
|
dsi->endptr = NULL_TREE;
|
|
}
|
|
dsi->writable = true;
|
|
dsi->stmt = stmt;
|
|
dsi->dont_invalidate = true;
|
|
}
|
|
return;
|
|
}
|
|
|
|
srclen = NULL_TREE;
|
|
si = NULL;
|
|
idx = get_stridx (src);
|
|
if (idx < 0)
|
|
srclen = build_int_cst (size_type_node, ~idx);
|
|
else if (idx > 0)
|
|
{
|
|
si = get_strinfo (idx);
|
|
if (si != NULL)
|
|
srclen = get_string_length (si);
|
|
}
|
|
|
|
loc = gimple_location (stmt);
|
|
dstlen = dsi->length;
|
|
endptr = dsi->endptr;
|
|
|
|
dsi = unshare_strinfo (dsi);
|
|
dsi->endptr = NULL_TREE;
|
|
dsi->stmt = NULL;
|
|
dsi->writable = true;
|
|
|
|
if (srclen != NULL_TREE)
|
|
{
|
|
dsi->length = fold_build2_loc (loc, PLUS_EXPR, TREE_TYPE (dsi->length),
|
|
dsi->length, srclen);
|
|
adjust_related_strinfos (loc, dsi, srclen);
|
|
dsi->dont_invalidate = true;
|
|
}
|
|
else
|
|
{
|
|
dsi->length = NULL;
|
|
if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY))
|
|
dsi->dont_invalidate = true;
|
|
}
|
|
|
|
if (si != NULL)
|
|
/* strcat src may not overlap dst, so src doesn't need to be
|
|
invalidated either. */
|
|
si->dont_invalidate = true;
|
|
|
|
/* For now. Could remove the lhs from the call and add
|
|
lhs = dst; afterwards. */
|
|
if (lhs)
|
|
return;
|
|
|
|
fn = NULL_TREE;
|
|
objsz = NULL_TREE;
|
|
switch (bcode)
|
|
{
|
|
case BUILT_IN_STRCAT:
|
|
if (srclen != NULL_TREE)
|
|
fn = builtin_decl_implicit (BUILT_IN_MEMCPY);
|
|
else
|
|
fn = builtin_decl_implicit (BUILT_IN_STRCPY);
|
|
break;
|
|
case BUILT_IN_STRCAT_CHK:
|
|
if (srclen != NULL_TREE)
|
|
fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK);
|
|
else
|
|
fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK);
|
|
objsz = gimple_call_arg (stmt, 2);
|
|
break;
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
if (fn == NULL_TREE)
|
|
return;
|
|
|
|
len = NULL_TREE;
|
|
if (srclen != NULL_TREE)
|
|
{
|
|
args = TYPE_ARG_TYPES (TREE_TYPE (fn));
|
|
type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args)));
|
|
|
|
len = fold_convert_loc (loc, type, unshare_expr (srclen));
|
|
len = fold_build2_loc (loc, PLUS_EXPR, type, len,
|
|
build_int_cst (type, 1));
|
|
len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true,
|
|
GSI_SAME_STMT);
|
|
}
|
|
if (endptr)
|
|
dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr));
|
|
else
|
|
dst = fold_build2_loc (loc, POINTER_PLUS_EXPR,
|
|
TREE_TYPE (dst), unshare_expr (dst),
|
|
fold_convert_loc (loc, sizetype,
|
|
unshare_expr (dstlen)));
|
|
dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true,
|
|
GSI_SAME_STMT);
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "Optimizing: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
if (srclen != NULL_TREE)
|
|
success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE),
|
|
dst, src, len, objsz);
|
|
else
|
|
success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE),
|
|
dst, src, objsz);
|
|
if (success)
|
|
{
|
|
stmt = gsi_stmt (*gsi);
|
|
update_stmt (stmt);
|
|
if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
{
|
|
fprintf (dump_file, "into: ");
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
}
|
|
/* If srclen == NULL, note that current string length can be
|
|
computed by transforming this strcpy into stpcpy. */
|
|
if (srclen == NULL_TREE && dsi->dont_invalidate)
|
|
dsi->stmt = stmt;
|
|
adjust_last_stmt (dsi, stmt, true);
|
|
if (srclen != NULL_TREE)
|
|
{
|
|
laststmt.stmt = stmt;
|
|
laststmt.len = srclen;
|
|
laststmt.stridx = dsi->idx;
|
|
}
|
|
}
|
|
else if (dump_file && (dump_flags & TDF_DETAILS) != 0)
|
|
fprintf (dump_file, "not possible.\n");
|
|
}
|
|
|
|
/* Handle a POINTER_PLUS_EXPR statement.
|
|
For p = "abcd" + 2; compute associated length, or if
|
|
p = q + off is pointing to a '\0' character of a string, call
|
|
zero_length_string on it. */
|
|
|
|
static void
|
|
handle_pointer_plus (gimple_stmt_iterator *gsi)
|
|
{
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
tree lhs = gimple_assign_lhs (stmt), off;
|
|
int idx = get_stridx (gimple_assign_rhs1 (stmt));
|
|
strinfo si, zsi;
|
|
|
|
if (idx == 0)
|
|
return;
|
|
|
|
if (idx < 0)
|
|
{
|
|
tree off = gimple_assign_rhs2 (stmt);
|
|
if (host_integerp (off, 1)
|
|
&& (unsigned HOST_WIDE_INT) tree_low_cst (off, 1)
|
|
<= (unsigned HOST_WIDE_INT) ~idx)
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs),
|
|
~(~idx - (int) tree_low_cst (off, 1)));
|
|
return;
|
|
}
|
|
|
|
si = get_strinfo (idx);
|
|
if (si == NULL || si->length == NULL_TREE)
|
|
return;
|
|
|
|
off = gimple_assign_rhs2 (stmt);
|
|
zsi = NULL;
|
|
if (operand_equal_p (si->length, off, 0))
|
|
zsi = zero_length_string (lhs, si);
|
|
else if (TREE_CODE (off) == SSA_NAME)
|
|
{
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (off);
|
|
if (gimple_assign_single_p (def_stmt)
|
|
&& operand_equal_p (si->length, gimple_assign_rhs1 (def_stmt), 0))
|
|
zsi = zero_length_string (lhs, si);
|
|
}
|
|
if (zsi != NULL
|
|
&& si->endptr != NULL_TREE
|
|
&& si->endptr != lhs
|
|
&& TREE_CODE (si->endptr) == SSA_NAME)
|
|
{
|
|
enum tree_code rhs_code
|
|
= useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr))
|
|
? SSA_NAME : NOP_EXPR;
|
|
gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr, NULL_TREE);
|
|
gcc_assert (gsi_stmt (*gsi) == stmt);
|
|
update_stmt (stmt);
|
|
}
|
|
}
|
|
|
|
/* Handle a single character store. */
|
|
|
|
static bool
|
|
handle_char_store (gimple_stmt_iterator *gsi)
|
|
{
|
|
int idx = -1;
|
|
strinfo si = NULL;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt);
|
|
|
|
if (TREE_CODE (lhs) == MEM_REF
|
|
&& TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME)
|
|
{
|
|
if (integer_zerop (TREE_OPERAND (lhs, 1)))
|
|
{
|
|
ssaname = TREE_OPERAND (lhs, 0);
|
|
idx = get_stridx (ssaname);
|
|
}
|
|
}
|
|
else
|
|
idx = get_addr_stridx (lhs);
|
|
|
|
if (idx > 0)
|
|
{
|
|
si = get_strinfo (idx);
|
|
if (si != NULL && si->length != NULL_TREE && integer_zerop (si->length))
|
|
{
|
|
if (initializer_zerop (gimple_assign_rhs1 (stmt)))
|
|
{
|
|
/* When storing '\0', the store can be removed
|
|
if we know it has been stored in the current function. */
|
|
if (!stmt_could_throw_p (stmt) && si->writable)
|
|
{
|
|
unlink_stmt_vdef (stmt);
|
|
release_defs (stmt);
|
|
gsi_remove (gsi, true);
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
si->writable = true;
|
|
si->dont_invalidate = true;
|
|
}
|
|
}
|
|
else
|
|
/* Otherwise this statement overwrites the '\0' with
|
|
something, if the previous stmt was a memcpy,
|
|
its length may be decreased. */
|
|
adjust_last_stmt (si, stmt, false);
|
|
}
|
|
else if (si != NULL)
|
|
{
|
|
si = unshare_strinfo (si);
|
|
si->length = build_int_cst (size_type_node, 0);
|
|
si->endptr = NULL;
|
|
si->prev = 0;
|
|
si->next = 0;
|
|
si->stmt = NULL;
|
|
si->first = 0;
|
|
si->writable = true;
|
|
if (ssaname && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname))
|
|
si->endptr = ssaname;
|
|
si->dont_invalidate = true;
|
|
}
|
|
}
|
|
else if (idx == 0 && initializer_zerop (gimple_assign_rhs1 (stmt)))
|
|
{
|
|
if (ssaname)
|
|
{
|
|
si = zero_length_string (ssaname, NULL);
|
|
if (si != NULL)
|
|
si->dont_invalidate = true;
|
|
}
|
|
else
|
|
{
|
|
int idx = new_addr_stridx (lhs);
|
|
if (idx != 0)
|
|
{
|
|
si = new_strinfo (build_fold_addr_expr (lhs), idx,
|
|
build_int_cst (size_type_node, 0));
|
|
set_strinfo (idx, si);
|
|
si->dont_invalidate = true;
|
|
}
|
|
}
|
|
if (si != NULL)
|
|
si->writable = true;
|
|
}
|
|
|
|
if (si != NULL && initializer_zerop (gimple_assign_rhs1 (stmt)))
|
|
{
|
|
/* Allow adjust_last_stmt to remove it if the stored '\0'
|
|
is immediately overwritten. */
|
|
laststmt.stmt = stmt;
|
|
laststmt.len = build_int_cst (size_type_node, 1);
|
|
laststmt.stridx = si->idx;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* Attempt to optimize a single statement at *GSI using string length
|
|
knowledge. */
|
|
|
|
static bool
|
|
strlen_optimize_stmt (gimple_stmt_iterator *gsi)
|
|
{
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
|
|
if (is_gimple_call (stmt))
|
|
{
|
|
tree callee = gimple_call_fndecl (stmt);
|
|
if (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL)
|
|
switch (DECL_FUNCTION_CODE (callee))
|
|
{
|
|
case BUILT_IN_STRLEN:
|
|
handle_builtin_strlen (gsi);
|
|
break;
|
|
case BUILT_IN_STRCHR:
|
|
handle_builtin_strchr (gsi);
|
|
break;
|
|
case BUILT_IN_STRCPY:
|
|
case BUILT_IN_STRCPY_CHK:
|
|
case BUILT_IN_STPCPY:
|
|
case BUILT_IN_STPCPY_CHK:
|
|
handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi);
|
|
break;
|
|
case BUILT_IN_MEMCPY:
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
case BUILT_IN_MEMPCPY:
|
|
case BUILT_IN_MEMPCPY_CHK:
|
|
handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi);
|
|
break;
|
|
case BUILT_IN_STRCAT:
|
|
case BUILT_IN_STRCAT_CHK:
|
|
handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
else if (is_gimple_assign (stmt))
|
|
{
|
|
tree lhs = gimple_assign_lhs (stmt);
|
|
|
|
if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (lhs)))
|
|
{
|
|
if (gimple_assign_single_p (stmt)
|
|
|| (gimple_assign_cast_p (stmt)
|
|
&& POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt)))))
|
|
{
|
|
int idx = get_stridx (gimple_assign_rhs1 (stmt));
|
|
VEC_replace (int, ssa_ver_to_stridx, SSA_NAME_VERSION (lhs),
|
|
idx);
|
|
}
|
|
else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
|
|
handle_pointer_plus (gsi);
|
|
}
|
|
else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs))
|
|
{
|
|
tree type = TREE_TYPE (lhs);
|
|
if (TREE_CODE (type) == ARRAY_TYPE)
|
|
type = TREE_TYPE (type);
|
|
if (TREE_CODE (type) == INTEGER_TYPE
|
|
&& TYPE_MODE (type) == TYPE_MODE (char_type_node)
|
|
&& TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node))
|
|
{
|
|
if (! handle_char_store (gsi))
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (gimple_vdef (stmt))
|
|
maybe_invalidate (stmt);
|
|
return true;
|
|
}
|
|
|
|
/* Recursively call maybe_invalidate on stmts that might be executed
|
|
in between dombb and current bb and that contain a vdef. Stop when
|
|
*count stmts are inspected, or if the whole strinfo vector has
|
|
been invalidated. */
|
|
|
|
static void
|
|
do_invalidate (basic_block dombb, gimple phi, bitmap visited, int *count)
|
|
{
|
|
unsigned int i, n = gimple_phi_num_args (phi);
|
|
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
tree vuse = gimple_phi_arg_def (phi, i);
|
|
gimple stmt = SSA_NAME_DEF_STMT (vuse);
|
|
basic_block bb = gimple_bb (stmt);
|
|
if (bb == NULL
|
|
|| bb == dombb
|
|
|| !bitmap_set_bit (visited, bb->index)
|
|
|| !dominated_by_p (CDI_DOMINATORS, bb, dombb))
|
|
continue;
|
|
while (1)
|
|
{
|
|
if (gimple_code (stmt) == GIMPLE_PHI)
|
|
{
|
|
do_invalidate (dombb, stmt, visited, count);
|
|
if (*count == 0)
|
|
return;
|
|
break;
|
|
}
|
|
if (--*count == 0)
|
|
return;
|
|
if (!maybe_invalidate (stmt))
|
|
{
|
|
*count = 0;
|
|
return;
|
|
}
|
|
vuse = gimple_vuse (stmt);
|
|
stmt = SSA_NAME_DEF_STMT (vuse);
|
|
if (gimple_bb (stmt) != bb)
|
|
{
|
|
bb = gimple_bb (stmt);
|
|
if (bb == NULL
|
|
|| bb == dombb
|
|
|| !bitmap_set_bit (visited, bb->index)
|
|
|| !dominated_by_p (CDI_DOMINATORS, bb, dombb))
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Callback for walk_dominator_tree. Attempt to optimize various
|
|
string ops by remembering string lenths pointed by pointer SSA_NAMEs. */
|
|
|
|
static void
|
|
strlen_enter_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
|
|
basic_block bb)
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb);
|
|
|
|
if (dombb == NULL)
|
|
stridx_to_strinfo = NULL;
|
|
else
|
|
{
|
|
stridx_to_strinfo = (VEC(strinfo, heap) *) dombb->aux;
|
|
if (stridx_to_strinfo)
|
|
{
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple phi = gsi_stmt (gsi);
|
|
if (virtual_operand_p (gimple_phi_result (phi)))
|
|
{
|
|
bitmap visited = BITMAP_ALLOC (NULL);
|
|
int count_vdef = 100;
|
|
do_invalidate (dombb, phi, visited, &count_vdef);
|
|
BITMAP_FREE (visited);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If all PHI arguments have the same string index, the PHI result
|
|
has it as well. */
|
|
for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
|
|
{
|
|
gimple phi = gsi_stmt (gsi);
|
|
tree result = gimple_phi_result (phi);
|
|
if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result)))
|
|
{
|
|
int idx = get_stridx (gimple_phi_arg_def (phi, 0));
|
|
if (idx != 0)
|
|
{
|
|
unsigned int i, n = gimple_phi_num_args (phi);
|
|
for (i = 1; i < n; i++)
|
|
if (idx != get_stridx (gimple_phi_arg_def (phi, i)))
|
|
break;
|
|
if (i == n)
|
|
VEC_replace (int, ssa_ver_to_stridx,
|
|
SSA_NAME_VERSION (result), idx);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Attempt to optimize individual statements. */
|
|
for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); )
|
|
if (strlen_optimize_stmt (&gsi))
|
|
gsi_next (&gsi);
|
|
|
|
bb->aux = stridx_to_strinfo;
|
|
if (VEC_length (strinfo, stridx_to_strinfo) && !strinfo_shared ())
|
|
VEC_replace (strinfo, stridx_to_strinfo, 0, (strinfo) bb);
|
|
}
|
|
|
|
/* Callback for walk_dominator_tree. Free strinfo vector if it is
|
|
owned by the current bb, clear bb->aux. */
|
|
|
|
static void
|
|
strlen_leave_block (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
|
|
basic_block bb)
|
|
{
|
|
if (bb->aux)
|
|
{
|
|
stridx_to_strinfo = (VEC(strinfo, heap) *) bb->aux;
|
|
if (VEC_length (strinfo, stridx_to_strinfo)
|
|
&& VEC_index (strinfo, stridx_to_strinfo, 0) == (strinfo) bb)
|
|
{
|
|
unsigned int i;
|
|
strinfo si;
|
|
|
|
for (i = 1; VEC_iterate (strinfo, stridx_to_strinfo, i, si); ++i)
|
|
free_strinfo (si);
|
|
VEC_free (strinfo, heap, stridx_to_strinfo);
|
|
}
|
|
bb->aux = NULL;
|
|
}
|
|
}
|
|
|
|
/* Main entry point. */
|
|
|
|
static unsigned int
|
|
tree_ssa_strlen (void)
|
|
{
|
|
struct dom_walk_data walk_data;
|
|
|
|
VEC_safe_grow_cleared (int, heap, ssa_ver_to_stridx, num_ssa_names);
|
|
max_stridx = 1;
|
|
strinfo_pool = create_alloc_pool ("strinfo_struct pool",
|
|
sizeof (struct strinfo_struct), 64);
|
|
|
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
|
|
/* String length optimization is implemented as a walk of the dominator
|
|
tree and a forward walk of statements within each block. */
|
|
walk_data.dom_direction = CDI_DOMINATORS;
|
|
walk_data.initialize_block_local_data = NULL;
|
|
walk_data.before_dom_children = strlen_enter_block;
|
|
walk_data.after_dom_children = strlen_leave_block;
|
|
walk_data.block_local_data_size = 0;
|
|
walk_data.global_data = NULL;
|
|
|
|
/* Initialize the dominator walker. */
|
|
init_walk_dominator_tree (&walk_data);
|
|
|
|
/* Recursively walk the dominator tree. */
|
|
walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
|
|
|
|
/* Finalize the dominator walker. */
|
|
fini_walk_dominator_tree (&walk_data);
|
|
|
|
VEC_free (int, heap, ssa_ver_to_stridx);
|
|
free_alloc_pool (strinfo_pool);
|
|
if (decl_to_stridxlist_htab)
|
|
{
|
|
obstack_free (&stridx_obstack, NULL);
|
|
htab_delete (decl_to_stridxlist_htab);
|
|
decl_to_stridxlist_htab = NULL;
|
|
}
|
|
laststmt.stmt = NULL;
|
|
laststmt.len = NULL_TREE;
|
|
laststmt.stridx = 0;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool
|
|
gate_strlen (void)
|
|
{
|
|
return flag_optimize_strlen != 0;
|
|
}
|
|
|
|
struct gimple_opt_pass pass_strlen =
|
|
{
|
|
{
|
|
GIMPLE_PASS,
|
|
"strlen", /* name */
|
|
OPTGROUP_NONE, /* optinfo_flags */
|
|
gate_strlen, /* gate */
|
|
tree_ssa_strlen, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_TREE_STRLEN, /* tv_id */
|
|
PROP_cfg | PROP_ssa, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_ggc_collect
|
|
| TODO_verify_ssa /* todo_flags_finish */
|
|
}
|
|
};
|