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Diffstat (limited to 'gcc-4.2.1-5666.3/gcc/tree-ssa-operands.c')
| -rw-r--r-- | gcc-4.2.1-5666.3/gcc/tree-ssa-operands.c | 2588 |
1 files changed, 2588 insertions, 0 deletions
diff --git a/gcc-4.2.1-5666.3/gcc/tree-ssa-operands.c b/gcc-4.2.1-5666.3/gcc/tree-ssa-operands.c new file mode 100644 index 000000000..3c24d2a93 --- /dev/null +++ b/gcc-4.2.1-5666.3/gcc/tree-ssa-operands.c @@ -0,0 +1,2588 @@ +/* SSA operands management for trees. + Copyright (C) 2003, 2004, 2005, 2006 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 2, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING. If not, write to +the Free Software Foundation, 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "tree.h" +#include "flags.h" +#include "function.h" +#include "diagnostic.h" +#include "tree-flow.h" +#include "tree-inline.h" +#include "tree-pass.h" +#include "ggc.h" +#include "timevar.h" +#include "toplev.h" +#include "langhooks.h" +#include "ipa-reference.h" + +/* This file contains the code required to manage the operands cache of the + SSA optimizer. For every stmt, we maintain an operand cache in the stmt + annotation. This cache contains operands that will be of interest to + optimizers and other passes wishing to manipulate the IL. + + The operand type are broken up into REAL and VIRTUAL operands. The real + operands are represented as pointers into the stmt's operand tree. Thus + any manipulation of the real operands will be reflected in the actual tree. + Virtual operands are represented solely in the cache, although the base + variable for the SSA_NAME may, or may not occur in the stmt's tree. + Manipulation of the virtual operands will not be reflected in the stmt tree. + + The routines in this file are concerned with creating this operand cache + from a stmt tree. + + The operand tree is the parsed by the various get_* routines which look + through the stmt tree for the occurrence of operands which may be of + interest, and calls are made to the append_* routines whenever one is + found. There are 5 of these routines, each representing one of the + 5 types of operands. Defs, Uses, Virtual Uses, Virtual May Defs, and + Virtual Must Defs. + + The append_* routines check for duplication, and simply keep a list of + unique objects for each operand type in the build_* extendable vectors. + + Once the stmt tree is completely parsed, the finalize_ssa_operands() + routine is called, which proceeds to perform the finalization routine + on each of the 5 operand vectors which have been built up. + + If the stmt had a previous operand cache, the finalization routines + attempt to match up the new operands with the old ones. If it's a perfect + match, the old vector is simply reused. If it isn't a perfect match, then + a new vector is created and the new operands are placed there. For + virtual operands, if the previous cache had SSA_NAME version of a + variable, and that same variable occurs in the same operands cache, then + the new cache vector will also get the same SSA_NAME. + + i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new operand + vector for VUSE, then the new vector will also be modified such that + it contains 'a_5' rather than 'a'. */ + +/* Flags to describe operand properties in helpers. */ + +/* By default, operands are loaded. */ +#define opf_none 0 + +/* Operand is the target of an assignment expression or a + call-clobbered variable. */ +#define opf_is_def (1 << 0) + +/* Operand is the target of an assignment expression. */ +#define opf_kill_def (1 << 1) + +/* No virtual operands should be created in the expression. This is used + when traversing ADDR_EXPR nodes which have different semantics than + other expressions. Inside an ADDR_EXPR node, the only operands that we + need to consider are indices into arrays. For instance, &a.b[i] should + generate a USE of 'i' but it should not generate a VUSE for 'a' nor a + VUSE for 'b'. */ +#define opf_no_vops (1 << 2) + +/* Operand is a "non-specific" kill for call-clobbers and such. This + is used to distinguish "reset the world" events from explicit + MODIFY_EXPRs. */ +#define opf_non_specific (1 << 3) + +/* Array for building all the def operands. */ +static VEC(tree,heap) *build_defs; + +/* Array for building all the use operands. */ +static VEC(tree,heap) *build_uses; + +/* Array for building all the V_MAY_DEF operands. */ +static VEC(tree,heap) *build_v_may_defs; + +/* Array for building all the VUSE operands. */ +static VEC(tree,heap) *build_vuses; + +/* Array for building all the V_MUST_DEF operands. */ +static VEC(tree,heap) *build_v_must_defs; + +/* These arrays are the cached operand vectors for call clobbered calls. */ +static bool ops_active = false; + +static GTY (()) struct ssa_operand_memory_d *operand_memory = NULL; +static unsigned operand_memory_index; + +static void get_expr_operands (tree, tree *, int); + +static def_optype_p free_defs = NULL; +static use_optype_p free_uses = NULL; +static vuse_optype_p free_vuses = NULL; +static maydef_optype_p free_maydefs = NULL; +static mustdef_optype_p free_mustdefs = NULL; + +/* Allocates operand OP of given TYPE from the appropriate free list, + or of the new value if the list is empty. */ + +#define ALLOC_OPTYPE(OP, TYPE) \ + do \ + { \ + TYPE##_optype_p ret = free_##TYPE##s; \ + if (ret) \ + free_##TYPE##s = ret->next; \ + else \ + ret = ssa_operand_alloc (sizeof (*ret)); \ + (OP) = ret; \ + } while (0) + +/* Return the DECL_UID of the base variable of T. */ + +static inline unsigned +get_name_decl (tree t) +{ + if (TREE_CODE (t) != SSA_NAME) + return DECL_UID (t); + else + return DECL_UID (SSA_NAME_VAR (t)); +} + + +/* Comparison function for qsort used in operand_build_sort_virtual. */ + +static int +operand_build_cmp (const void *p, const void *q) +{ + tree e1 = *((const tree *)p); + tree e2 = *((const tree *)q); + unsigned int u1,u2; + + u1 = get_name_decl (e1); + u2 = get_name_decl (e2); + + /* We want to sort in ascending order. They can never be equal. */ +#ifdef ENABLE_CHECKING + gcc_assert (u1 != u2); +#endif + return (u1 > u2 ? 1 : -1); +} + + +/* Sort the virtual operands in LIST from lowest DECL_UID to highest. */ + +static inline void +operand_build_sort_virtual (VEC(tree,heap) *list) +{ + int num = VEC_length (tree, list); + + if (num < 2) + return; + + if (num == 2) + { + if (get_name_decl (VEC_index (tree, list, 0)) + > get_name_decl (VEC_index (tree, list, 1))) + { + /* Swap elements if in the wrong order. */ + tree tmp = VEC_index (tree, list, 0); + VEC_replace (tree, list, 0, VEC_index (tree, list, 1)); + VEC_replace (tree, list, 1, tmp); + } + return; + } + + /* There are 3 or more elements, call qsort. */ + qsort (VEC_address (tree, list), + VEC_length (tree, list), + sizeof (tree), + operand_build_cmp); +} + + +/* Return true if the SSA operands cache is active. */ + +bool +ssa_operands_active (void) +{ + return ops_active; +} + + +/* Structure storing statistics on how many call clobbers we have, and + how many where avoided. */ + +static struct +{ + /* Number of call-clobbered ops we attempt to add to calls in + add_call_clobber_ops. */ + unsigned int clobbered_vars; + + /* Number of write-clobbers (V_MAY_DEFs) avoided by using + not_written information. */ + unsigned int static_write_clobbers_avoided; + + /* Number of reads (VUSEs) avoided by using not_read information. */ + unsigned int static_read_clobbers_avoided; + + /* Number of write-clobbers avoided because the variable can't escape to + this call. */ + unsigned int unescapable_clobbers_avoided; + + /* Number of read-only uses we attempt to add to calls in + add_call_read_ops. */ + unsigned int readonly_clobbers; + + /* Number of read-only uses we avoid using not_read information. */ + unsigned int static_readonly_clobbers_avoided; +} clobber_stats; + + +/* Initialize the operand cache routines. */ + +void +init_ssa_operands (void) +{ + build_defs = VEC_alloc (tree, heap, 5); + build_uses = VEC_alloc (tree, heap, 10); + build_vuses = VEC_alloc (tree, heap, 25); + build_v_may_defs = VEC_alloc (tree, heap, 25); + build_v_must_defs = VEC_alloc (tree, heap, 25); + + gcc_assert (operand_memory == NULL); + operand_memory_index = SSA_OPERAND_MEMORY_SIZE; + ops_active = true; + memset (&clobber_stats, 0, sizeof (clobber_stats)); +} + + +/* Dispose of anything required by the operand routines. */ + +void +fini_ssa_operands (void) +{ + struct ssa_operand_memory_d *ptr; + VEC_free (tree, heap, build_defs); + VEC_free (tree, heap, build_uses); + VEC_free (tree, heap, build_v_must_defs); + VEC_free (tree, heap, build_v_may_defs); + VEC_free (tree, heap, build_vuses); + free_defs = NULL; + free_uses = NULL; + free_vuses = NULL; + free_maydefs = NULL; + free_mustdefs = NULL; + while ((ptr = operand_memory) != NULL) + { + operand_memory = operand_memory->next; + ggc_free (ptr); + } + + ops_active = false; + + if (dump_file && (dump_flags & TDF_STATS)) + { + fprintf (dump_file, "Original clobbered vars:%d\n", + clobber_stats.clobbered_vars); + fprintf (dump_file, "Static write clobbers avoided:%d\n", + clobber_stats.static_write_clobbers_avoided); + fprintf (dump_file, "Static read clobbers avoided:%d\n", + clobber_stats.static_read_clobbers_avoided); + fprintf (dump_file, "Unescapable clobbers avoided:%d\n", + clobber_stats.unescapable_clobbers_avoided); + fprintf (dump_file, "Original read-only clobbers:%d\n", + clobber_stats.readonly_clobbers); + fprintf (dump_file, "Static read-only clobbers avoided:%d\n", + clobber_stats.static_readonly_clobbers_avoided); + } +} + + +/* Return memory for operands of SIZE chunks. */ + +static inline void * +ssa_operand_alloc (unsigned size) +{ + char *ptr; + if (operand_memory_index + size >= SSA_OPERAND_MEMORY_SIZE) + { + struct ssa_operand_memory_d *ptr; + ptr = GGC_NEW (struct ssa_operand_memory_d); + ptr->next = operand_memory; + operand_memory = ptr; + operand_memory_index = 0; + } + ptr = &(operand_memory->mem[operand_memory_index]); + operand_memory_index += size; + return ptr; +} + + + +/* This routine makes sure that PTR is in an immediate use list, and makes + sure the stmt pointer is set to the current stmt. */ + +static inline void +set_virtual_use_link (use_operand_p ptr, tree stmt) +{ + /* fold_stmt may have changed the stmt pointers. */ + if (ptr->stmt != stmt) + ptr->stmt = stmt; + + /* If this use isn't in a list, add it to the correct list. */ + if (!ptr->prev) + link_imm_use (ptr, *(ptr->use)); +} + +/* Appends ELT after TO, and moves the TO pointer to ELT. */ + +#define APPEND_OP_AFTER(ELT, TO) \ + do \ + { \ + (TO)->next = (ELT); \ + (TO) = (ELT); \ + } while (0) + +/* Appends head of list FROM after TO, and move both pointers + to their successors. */ + +#define MOVE_HEAD_AFTER(FROM, TO) \ + do \ + { \ + APPEND_OP_AFTER (FROM, TO); \ + (FROM) = (FROM)->next; \ + } while (0) + +/* Moves OP to appropriate freelist. OP is set to its successor. */ + +#define MOVE_HEAD_TO_FREELIST(OP, TYPE) \ + do \ + { \ + TYPE##_optype_p next = (OP)->next; \ + (OP)->next = free_##TYPE##s; \ + free_##TYPE##s = (OP); \ + (OP) = next; \ + } while (0) + +/* Initializes immediate use at USE_PTR to value VAL, and links it to the list + of immediate uses. STMT is the current statement. */ + +#define INITIALIZE_USE(USE_PTR, VAL, STMT) \ + do \ + { \ + (USE_PTR)->use = (VAL); \ + link_imm_use_stmt ((USE_PTR), *(VAL), (STMT)); \ + } while (0) + +/* Adds OP to the list of defs after LAST, and moves + LAST to the new element. */ + +static inline void +add_def_op (tree *op, def_optype_p *last) +{ + def_optype_p new; + + ALLOC_OPTYPE (new, def); + DEF_OP_PTR (new) = op; + APPEND_OP_AFTER (new, *last); +} + +/* Adds OP to the list of uses of statement STMT after LAST, and moves + LAST to the new element. */ + +static inline void +add_use_op (tree stmt, tree *op, use_optype_p *last) +{ + use_optype_p new; + + ALLOC_OPTYPE (new, use); + INITIALIZE_USE (USE_OP_PTR (new), op, stmt); + APPEND_OP_AFTER (new, *last); +} + +/* Adds OP to the list of vuses of statement STMT after LAST, and moves + LAST to the new element. */ + +static inline void +add_vuse_op (tree stmt, tree op, vuse_optype_p *last) +{ + vuse_optype_p new; + + ALLOC_OPTYPE (new, vuse); + VUSE_OP (new) = op; + INITIALIZE_USE (VUSE_OP_PTR (new), &VUSE_OP (new), stmt); + APPEND_OP_AFTER (new, *last); +} + +/* Adds OP to the list of maydefs of statement STMT after LAST, and moves + LAST to the new element. */ + +static inline void +add_maydef_op (tree stmt, tree op, maydef_optype_p *last) +{ + maydef_optype_p new; + + ALLOC_OPTYPE (new, maydef); + MAYDEF_RESULT (new) = op; + MAYDEF_OP (new) = op; + INITIALIZE_USE (MAYDEF_OP_PTR (new), &MAYDEF_OP (new), stmt); + APPEND_OP_AFTER (new, *last); +} + +/* Adds OP to the list of mustdefs of statement STMT after LAST, and moves + LAST to the new element. */ + +static inline void +add_mustdef_op (tree stmt, tree op, mustdef_optype_p *last) +{ + mustdef_optype_p new; + + ALLOC_OPTYPE (new, mustdef); + MUSTDEF_RESULT (new) = op; + MUSTDEF_KILL (new) = op; + INITIALIZE_USE (MUSTDEF_KILL_PTR (new), &MUSTDEF_KILL (new), stmt); + APPEND_OP_AFTER (new, *last); +} + +/* Takes elements from build_defs and turns them into def operands of STMT. + TODO -- Given that def operands list is not necessarily sorted, merging + the operands this way does not make much sense. + -- Make build_defs VEC of tree *. */ + +static inline void +finalize_ssa_def_ops (tree stmt) +{ + unsigned new_i; + struct def_optype_d new_list; + def_optype_p old_ops, last; + tree *old_base; + + new_list.next = NULL; + last = &new_list; + + old_ops = DEF_OPS (stmt); + + new_i = 0; + while (old_ops && new_i < VEC_length (tree, build_defs)) + { + tree *new_base = (tree *) VEC_index (tree, build_defs, new_i); + old_base = DEF_OP_PTR (old_ops); + + if (old_base == new_base) + { + /* if variables are the same, reuse this node. */ + MOVE_HEAD_AFTER (old_ops, last); + new_i++; + } + else if (old_base < new_base) + { + /* if old is less than new, old goes to the free list. */ + MOVE_HEAD_TO_FREELIST (old_ops, def); + } + else + { + /* This is a new operand. */ + add_def_op (new_base, &last); + new_i++; + } + } + + /* If there is anything remaining in the build_defs list, simply emit it. */ + for ( ; new_i < VEC_length (tree, build_defs); new_i++) + add_def_op ((tree *) VEC_index (tree, build_defs, new_i), &last); + + last->next = NULL; + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + old_ops->next = free_defs; + free_defs = old_ops; + } + + /* Now set the stmt's operands. */ + DEF_OPS (stmt) = new_list.next; + +#ifdef ENABLE_CHECKING + { + def_optype_p ptr; + unsigned x = 0; + for (ptr = DEF_OPS (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_defs)); + } +#endif +} + +/* This routine will create stmt operands for STMT from the def build list. */ + +static void +finalize_ssa_defs (tree stmt) +{ + unsigned int num = VEC_length (tree, build_defs); + + /* There should only be a single real definition per assignment. */ + gcc_assert ((stmt && TREE_CODE (stmt) != MODIFY_EXPR) || num <= 1); + + /* If there is an old list, often the new list is identical, or close, so + find the elements at the beginning that are the same as the vector. */ + finalize_ssa_def_ops (stmt); + VEC_truncate (tree, build_defs, 0); +} + +/* Takes elements from build_uses and turns them into use operands of STMT. + TODO -- Make build_uses VEC of tree *. */ + +static inline void +finalize_ssa_use_ops (tree stmt) +{ + unsigned new_i; + struct use_optype_d new_list; + use_optype_p old_ops, ptr, last; + + new_list.next = NULL; + last = &new_list; + + old_ops = USE_OPS (stmt); + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (ptr = old_ops; ptr; ptr = ptr->next) + delink_imm_use (USE_OP_PTR (ptr)); + old_ops->next = free_uses; + free_uses = old_ops; + } + + /* Now create nodes for all the new nodes. */ + for (new_i = 0; new_i < VEC_length (tree, build_uses); new_i++) + add_use_op (stmt, (tree *) VEC_index (tree, build_uses, new_i), &last); + + last->next = NULL; + + /* Now set the stmt's operands. */ + USE_OPS (stmt) = new_list.next; + +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_uses)); + } +#endif +} + +/* Return a new use operand vector for STMT, comparing to OLD_OPS_P. */ + +static void +finalize_ssa_uses (tree stmt) +{ +#ifdef ENABLE_CHECKING + { + unsigned x; + unsigned num = VEC_length (tree, build_uses); + + /* If the pointer to the operand is the statement itself, something is + wrong. It means that we are pointing to a local variable (the + initial call to update_stmt_operands does not pass a pointer to a + statement). */ + for (x = 0; x < num; x++) + gcc_assert (*((tree *)VEC_index (tree, build_uses, x)) != stmt); + } +#endif + finalize_ssa_use_ops (stmt); + VEC_truncate (tree, build_uses, 0); +} + + +/* Takes elements from build_v_may_defs and turns them into maydef operands of + STMT. */ + +static inline void +finalize_ssa_v_may_def_ops (tree stmt) +{ + unsigned new_i; + struct maydef_optype_d new_list; + maydef_optype_p old_ops, ptr, last; + tree act; + unsigned old_base, new_base; + + new_list.next = NULL; + last = &new_list; + + old_ops = MAYDEF_OPS (stmt); + + new_i = 0; + while (old_ops && new_i < VEC_length (tree, build_v_may_defs)) + { + act = VEC_index (tree, build_v_may_defs, new_i); + new_base = get_name_decl (act); + old_base = get_name_decl (MAYDEF_OP (old_ops)); + + if (old_base == new_base) + { + /* if variables are the same, reuse this node. */ + MOVE_HEAD_AFTER (old_ops, last); + set_virtual_use_link (MAYDEF_OP_PTR (last), stmt); + new_i++; + } + else if (old_base < new_base) + { + /* if old is less than new, old goes to the free list. */ + delink_imm_use (MAYDEF_OP_PTR (old_ops)); + MOVE_HEAD_TO_FREELIST (old_ops, maydef); + } + else + { + /* This is a new operand. */ + add_maydef_op (stmt, act, &last); + new_i++; + } + } + + /* If there is anything remaining in the build_v_may_defs list, simply emit it. */ + for ( ; new_i < VEC_length (tree, build_v_may_defs); new_i++) + add_maydef_op (stmt, VEC_index (tree, build_v_may_defs, new_i), &last); + + last->next = NULL; + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (ptr = old_ops; ptr; ptr = ptr->next) + delink_imm_use (MAYDEF_OP_PTR (ptr)); + old_ops->next = free_maydefs; + free_maydefs = old_ops; + } + + /* Now set the stmt's operands. */ + MAYDEF_OPS (stmt) = new_list.next; + +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = MAYDEF_OPS (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_v_may_defs)); + } +#endif +} + +static void +finalize_ssa_v_may_defs (tree stmt) +{ + finalize_ssa_v_may_def_ops (stmt); +} + + +/* Clear the in_list bits and empty the build array for V_MAY_DEFs. */ + +static inline void +cleanup_v_may_defs (void) +{ + unsigned x, num; + num = VEC_length (tree, build_v_may_defs); + + for (x = 0; x < num; x++) + { + tree t = VEC_index (tree, build_v_may_defs, x); + if (TREE_CODE (t) != SSA_NAME) + { + var_ann_t ann = var_ann (t); + ann->in_v_may_def_list = 0; + } + } + VEC_truncate (tree, build_v_may_defs, 0); +} + + +/* Takes elements from build_vuses and turns them into vuse operands of + STMT. */ + +static inline void +finalize_ssa_vuse_ops (tree stmt) +{ + unsigned new_i; + struct vuse_optype_d new_list; + vuse_optype_p old_ops, ptr, last; + tree act; + unsigned old_base, new_base; + + new_list.next = NULL; + last = &new_list; + + old_ops = VUSE_OPS (stmt); + + new_i = 0; + while (old_ops && new_i < VEC_length (tree, build_vuses)) + { + act = VEC_index (tree, build_vuses, new_i); + new_base = get_name_decl (act); + old_base = get_name_decl (VUSE_OP (old_ops)); + + if (old_base == new_base) + { + /* if variables are the same, reuse this node. */ + MOVE_HEAD_AFTER (old_ops, last); + set_virtual_use_link (VUSE_OP_PTR (last), stmt); + new_i++; + } + else if (old_base < new_base) + { + /* if old is less than new, old goes to the free list. */ + delink_imm_use (USE_OP_PTR (old_ops)); + MOVE_HEAD_TO_FREELIST (old_ops, vuse); + } + else + { + /* This is a new operand. */ + add_vuse_op (stmt, act, &last); + new_i++; + } + } + + /* If there is anything remaining in the build_vuses list, simply emit it. */ + for ( ; new_i < VEC_length (tree, build_vuses); new_i++) + add_vuse_op (stmt, VEC_index (tree, build_vuses, new_i), &last); + + last->next = NULL; + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (ptr = old_ops; ptr; ptr = ptr->next) + delink_imm_use (VUSE_OP_PTR (ptr)); + old_ops->next = free_vuses; + free_vuses = old_ops; + } + + /* Now set the stmt's operands. */ + VUSE_OPS (stmt) = new_list.next; + +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = VUSE_OPS (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_vuses)); + } +#endif +} + +/* Return a new VUSE operand vector, comparing to OLD_OPS_P. */ + +static void +finalize_ssa_vuses (tree stmt) +{ + unsigned num, num_v_may_defs; + unsigned vuse_index; + + /* Remove superfluous VUSE operands. If the statement already has a + V_MAY_DEF operation for a variable 'a', then a VUSE for 'a' is + not needed because V_MAY_DEFs imply a VUSE of the variable. For + instance, suppose that variable 'a' is aliased: + + # VUSE <a_2> + # a_3 = V_MAY_DEF <a_2> + a = a + 1; + + The VUSE <a_2> is superfluous because it is implied by the + V_MAY_DEF operation. */ + num = VEC_length (tree, build_vuses); + num_v_may_defs = VEC_length (tree, build_v_may_defs); + + if (num > 0 && num_v_may_defs > 0) + { + for (vuse_index = 0; vuse_index < VEC_length (tree, build_vuses); ) + { + tree vuse; + vuse = VEC_index (tree, build_vuses, vuse_index); + if (TREE_CODE (vuse) != SSA_NAME) + { + var_ann_t ann = var_ann (vuse); + ann->in_vuse_list = 0; + if (ann->in_v_may_def_list) + { + VEC_ordered_remove (tree, build_vuses, vuse_index); + continue; + } + } + vuse_index++; + } + } + else + { + /* Clear out the in_list bits. */ + for (vuse_index = 0; + vuse_index < VEC_length (tree, build_vuses); + vuse_index++) + { + tree t = VEC_index (tree, build_vuses, vuse_index); + if (TREE_CODE (t) != SSA_NAME) + { + var_ann_t ann = var_ann (t); + ann->in_vuse_list = 0; + } + } + } + + finalize_ssa_vuse_ops (stmt); + + /* The V_MAY_DEF build vector wasn't cleaned up because we needed it. */ + cleanup_v_may_defs (); + + /* Free the VUSEs build vector. */ + VEC_truncate (tree, build_vuses, 0); + +} + +/* Takes elements from build_v_must_defs and turns them into mustdef operands of + STMT. */ + +static inline void +finalize_ssa_v_must_def_ops (tree stmt) +{ + unsigned new_i; + struct mustdef_optype_d new_list; + mustdef_optype_p old_ops, ptr, last; + tree act; + unsigned old_base, new_base; + + new_list.next = NULL; + last = &new_list; + + old_ops = MUSTDEF_OPS (stmt); + + new_i = 0; + while (old_ops && new_i < VEC_length (tree, build_v_must_defs)) + { + act = VEC_index (tree, build_v_must_defs, new_i); + new_base = get_name_decl (act); + old_base = get_name_decl (MUSTDEF_KILL (old_ops)); + + if (old_base == new_base) + { + /* If variables are the same, reuse this node. */ + MOVE_HEAD_AFTER (old_ops, last); + set_virtual_use_link (MUSTDEF_KILL_PTR (last), stmt); + new_i++; + } + else if (old_base < new_base) + { + /* If old is less than new, old goes to the free list. */ + delink_imm_use (MUSTDEF_KILL_PTR (old_ops)); + MOVE_HEAD_TO_FREELIST (old_ops, mustdef); + } + else + { + /* This is a new operand. */ + add_mustdef_op (stmt, act, &last); + new_i++; + } + } + + /* If there is anything remaining in the build_v_must_defs list, simply emit it. */ + for ( ; new_i < VEC_length (tree, build_v_must_defs); new_i++) + add_mustdef_op (stmt, VEC_index (tree, build_v_must_defs, new_i), &last); + + last->next = NULL; + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (ptr = old_ops; ptr; ptr = ptr->next) + delink_imm_use (MUSTDEF_KILL_PTR (ptr)); + old_ops->next = free_mustdefs; + free_mustdefs = old_ops; + } + + /* Now set the stmt's operands. */ + MUSTDEF_OPS (stmt) = new_list.next; + +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = MUSTDEF_OPS (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_v_must_defs)); + } +#endif +} + +static void +finalize_ssa_v_must_defs (tree stmt) +{ + /* In the presence of subvars, there may be more than one V_MUST_DEF + per statement (one for each subvar). It is a bit expensive to + verify that all must-defs in a statement belong to subvars if + there is more than one must-def, so we don't do it. Suffice to + say, if you reach here without having subvars, and have num >1, + you have hit a bug. */ + finalize_ssa_v_must_def_ops (stmt); + VEC_truncate (tree, build_v_must_defs, 0); +} + + +/* Finalize all the build vectors, fill the new ones into INFO. */ + +static inline void +finalize_ssa_stmt_operands (tree stmt) +{ + finalize_ssa_defs (stmt); + finalize_ssa_uses (stmt); + finalize_ssa_v_must_defs (stmt); + finalize_ssa_v_may_defs (stmt); + finalize_ssa_vuses (stmt); +} + + +/* Start the process of building up operands vectors in INFO. */ + +static inline void +start_ssa_stmt_operands (void) +{ + gcc_assert (VEC_length (tree, build_defs) == 0); + gcc_assert (VEC_length (tree, build_uses) == 0); + gcc_assert (VEC_length (tree, build_vuses) == 0); + gcc_assert (VEC_length (tree, build_v_may_defs) == 0); + gcc_assert (VEC_length (tree, build_v_must_defs) == 0); +} + + +/* Add DEF_P to the list of pointers to operands. */ + +static inline void +append_def (tree *def_p) +{ + VEC_safe_push (tree, heap, build_defs, (tree)def_p); +} + + +/* Add USE_P to the list of pointers to operands. */ + +static inline void +append_use (tree *use_p) +{ + VEC_safe_push (tree, heap, build_uses, (tree)use_p); +} + + +/* Add a new virtual may def for variable VAR to the build array. */ + +static inline void +append_v_may_def (tree var) +{ + if (TREE_CODE (var) != SSA_NAME) + { + var_ann_t ann = get_var_ann (var); + + /* Don't allow duplicate entries. */ + if (ann->in_v_may_def_list) + return; + ann->in_v_may_def_list = 1; + } + + VEC_safe_push (tree, heap, build_v_may_defs, (tree)var); +} + + +/* Add VAR to the list of virtual uses. */ + +static inline void +append_vuse (tree var) +{ + /* Don't allow duplicate entries. */ + if (TREE_CODE (var) != SSA_NAME) + { + var_ann_t ann = get_var_ann (var); + + if (ann->in_vuse_list || ann->in_v_may_def_list) + return; + ann->in_vuse_list = 1; + } + + VEC_safe_push (tree, heap, build_vuses, (tree)var); +} + + +/* Add VAR to the list of virtual must definitions for INFO. */ + +static inline void +append_v_must_def (tree var) +{ + unsigned i; + + /* Don't allow duplicate entries. */ + for (i = 0; i < VEC_length (tree, build_v_must_defs); i++) + if (var == VEC_index (tree, build_v_must_defs, i)) + return; + + VEC_safe_push (tree, heap, build_v_must_defs, (tree)var); +} + + +/* REF is a tree that contains the entire pointer dereference + expression, if available, or NULL otherwise. ALIAS is the variable + we are asking if REF can access. OFFSET and SIZE come from the + memory access expression that generated this virtual operand. */ + +static bool +access_can_touch_variable (tree ref, tree alias, HOST_WIDE_INT offset, + HOST_WIDE_INT size) +{ + bool offsetgtz = offset > 0; + unsigned HOST_WIDE_INT uoffset = (unsigned HOST_WIDE_INT) offset; + tree base = ref ? get_base_address (ref) : NULL; + + /* If ALIAS is .GLOBAL_VAR then the memory reference REF must be + using a call-clobbered memory tag. By definition, call-clobbered + memory tags can always touch .GLOBAL_VAR. */ + if (alias == global_var) + return true; + + /* We cannot prune nonlocal aliases because they are not type + specific. */ + if (alias == nonlocal_all) + return true; + + /* If ALIAS is an SFT, it can't be touched if the offset + and size of the access is not overlapping with the SFT offset and + size. This is only true if we are accessing through a pointer + to a type that is the same as SFT_PARENT_VAR. Otherwise, we may + be accessing through a pointer to some substruct of the + structure, and if we try to prune there, we will have the wrong + offset, and get the wrong answer. + i.e., we can't prune without more work if we have something like + + struct gcc_target + { + struct asm_out + { + const char *byte_op; + struct asm_int_op + { + const char *hi; + } aligned_op; + } asm_out; + } targetm; + + foo = &targetm.asm_out.aligned_op; + return foo->hi; + + SFT.1, which represents hi, will have SFT_OFFSET=32 because in + terms of SFT_PARENT_VAR, that is where it is. + However, the access through the foo pointer will be at offset 0. */ + if (size != -1 + && TREE_CODE (alias) == STRUCT_FIELD_TAG + && base + && TREE_TYPE (base) == TREE_TYPE (SFT_PARENT_VAR (alias)) + && !overlap_subvar (offset, size, alias, NULL)) + { +#ifdef ACCESS_DEBUGGING + fprintf (stderr, "Access to "); + print_generic_expr (stderr, ref, 0); + fprintf (stderr, " may not touch "); + print_generic_expr (stderr, alias, 0); + fprintf (stderr, " in function %s\n", get_name (current_function_decl)); +#endif + return false; + } + + /* Without strict aliasing, it is impossible for a component access + through a pointer to touch a random variable, unless that + variable *is* a structure or a pointer. + + That is, given p->c, and some random global variable b, + there is no legal way that p->c could be an access to b. + + Without strict aliasing on, we consider it legal to do something + like: + + struct foos { int l; }; + int foo; + static struct foos *getfoo(void); + int main (void) + { + struct foos *f = getfoo(); + f->l = 1; + foo = 2; + if (f->l == 1) + abort(); + exit(0); + } + static struct foos *getfoo(void) + { return (struct foos *)&foo; } + + (taken from 20000623-1.c) + + The docs also say/imply that access through union pointers + is legal (but *not* if you take the address of the union member, + i.e. the inverse), such that you can do + + typedef union { + int d; + } U; + + int rv; + void breakme() + { + U *rv0; + U *pretmp = (U*)&rv; + rv0 = pretmp; + rv0->d = 42; + } + To implement this, we just punt on accesses through union + pointers entirely. + */ + else if (ref + && flag_strict_aliasing + && TREE_CODE (ref) != INDIRECT_REF + && !MTAG_P (alias) + && (TREE_CODE (base) != INDIRECT_REF + || TREE_CODE (TREE_TYPE (base)) != UNION_TYPE) + && !AGGREGATE_TYPE_P (TREE_TYPE (alias)) + && TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE + && !POINTER_TYPE_P (TREE_TYPE (alias)) + /* When the struct has may_alias attached to it, we need not to + return true. */ + && get_alias_set (base)) + { +#ifdef ACCESS_DEBUGGING + fprintf (stderr, "Access to "); + print_generic_expr (stderr, ref, 0); + fprintf (stderr, " may not touch "); + print_generic_expr (stderr, alias, 0); + fprintf (stderr, " in function %s\n", get_name (current_function_decl)); +#endif + return false; + } + + /* If the offset of the access is greater than the size of one of + the possible aliases, it can't be touching that alias, because it + would be past the end of the structure. */ + else if (ref + && flag_strict_aliasing + && TREE_CODE (ref) != INDIRECT_REF + && !MTAG_P (alias) + && !POINTER_TYPE_P (TREE_TYPE (alias)) + && offsetgtz + && DECL_SIZE (alias) + && TREE_CODE (DECL_SIZE (alias)) == INTEGER_CST + && uoffset > TREE_INT_CST_LOW (DECL_SIZE (alias))) + { +#ifdef ACCESS_DEBUGGING + fprintf (stderr, "Access to "); + print_generic_expr (stderr, ref, 0); + fprintf (stderr, " may not touch "); + print_generic_expr (stderr, alias, 0); + fprintf (stderr, " in function %s\n", get_name (current_function_decl)); +#endif + return false; + } + + return true; +} + + +/* Add VAR to the virtual operands array. FLAGS is as in + get_expr_operands. FULL_REF is a tree that contains the entire + pointer dereference expression, if available, or NULL otherwise. + OFFSET and SIZE come from the memory access expression that + generated this virtual operand. FOR_CLOBBER is true is this is + adding a virtual operand for a call clobber. */ + +static void +add_virtual_operand (tree var, stmt_ann_t s_ann, int flags, + tree full_ref, HOST_WIDE_INT offset, + HOST_WIDE_INT size, bool for_clobber) +{ + VEC(tree,gc) *aliases; + tree sym; + var_ann_t v_ann; + + sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); + v_ann = var_ann (sym); + + /* Mark statements with volatile operands. Optimizers should back + off from statements having volatile operands. */ + if (TREE_THIS_VOLATILE (sym) && s_ann) + s_ann->has_volatile_ops = true; + + /* If the variable cannot be modified and this is a V_MAY_DEF change + it into a VUSE. This happens when read-only variables are marked + call-clobbered and/or aliased to writable variables. So we only + check that this only happens on non-specific stores. + + Note that if this is a specific store, i.e. associated with a + modify_expr, then we can't suppress the V_MAY_DEF, lest we run + into validation problems. + + This can happen when programs cast away const, leaving us with a + store to read-only memory. If the statement is actually executed + at runtime, then the program is ill formed. If the statement is + not executed then all is well. At the very least, we cannot ICE. */ + if ((flags & opf_non_specific) && unmodifiable_var_p (var)) + flags &= ~(opf_is_def | opf_kill_def); + + /* The variable is not a GIMPLE register. Add it (or its aliases) to + virtual operands, unless the caller has specifically requested + not to add virtual operands (used when adding operands inside an + ADDR_EXPR expression). */ + if (flags & opf_no_vops) + return; + + aliases = v_ann->may_aliases; + if (aliases == NULL) + { + /* The variable is not aliased or it is an alias tag. */ + if (flags & opf_is_def) + { + if (flags & opf_kill_def) + { + /* V_MUST_DEF for non-aliased, non-GIMPLE register + variable definitions. */ + gcc_assert (!MTAG_P (var) + || TREE_CODE (var) == STRUCT_FIELD_TAG); + append_v_must_def (var); + } + else + { + /* Add a V_MAY_DEF for call-clobbered variables and + memory tags. */ + append_v_may_def (var); + } + } + else + append_vuse (var); + } + else + { + unsigned i; + tree al; + + /* The variable is aliased. Add its aliases to the virtual + operands. */ + gcc_assert (VEC_length (tree, aliases) != 0); + + if (flags & opf_is_def) + { + + bool none_added = true; + + for (i = 0; VEC_iterate (tree, aliases, i, al); i++) + { + if (!access_can_touch_variable (full_ref, al, offset, size)) + continue; + + none_added = false; + append_v_may_def (al); + } + + /* If the variable is also an alias tag, add a virtual + operand for it, otherwise we will miss representing + references to the members of the variable's alias set. + This fixes the bug in gcc.c-torture/execute/20020503-1.c. + + It is also necessary to add bare defs on clobbers for + SMT's, so that bare SMT uses caused by pruning all the + aliases will link up properly with calls. In order to + keep the number of these bare defs we add down to the + minimum necessary, we keep track of which SMT's were used + alone in statement vdefs or VUSEs. */ + if (v_ann->is_aliased + || none_added + || (TREE_CODE (var) == SYMBOL_MEMORY_TAG + && for_clobber + && SMT_USED_ALONE (var))) + { + /* Every bare SMT def we add should have SMT_USED_ALONE + set on it, or else we will get the wrong answer on + clobbers. Sadly, this assertion trips on code that + violates strict aliasing rules, because they *do* get + the clobbers wrong, since it is illegal code. As a + result, we currently only enable it for aliasing + debugging. Someone might wish to turn this code into + a nice strict-aliasing warning, since we *know* it + will get the wrong answer... */ +#ifdef ACCESS_DEBUGGING + if (none_added + && !updating_used_alone && aliases_computed_p + && TREE_CODE (var) == SYMBOL_MEMORY_TAG) + gcc_assert (SMT_USED_ALONE (var)); +#endif + append_v_may_def (var); + } + } + else + { + bool none_added = true; + for (i = 0; VEC_iterate (tree, aliases, i, al); i++) + { + if (!access_can_touch_variable (full_ref, al, offset, size)) + continue; + none_added = false; + append_vuse (al); + } + + /* Similarly, append a virtual uses for VAR itself, when + it is an alias tag. */ + if (v_ann->is_aliased || none_added) + append_vuse (var); + } + } +} + + +/* Add *VAR_P to the appropriate operand array for S_ANN. FLAGS is as in + get_expr_operands. If *VAR_P is a GIMPLE register, it will be added to + the statement's real operands, otherwise it is added to virtual + operands. */ + +static void +add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags) +{ + bool is_real_op; + tree var, sym; + var_ann_t v_ann; + + var = *var_p; + gcc_assert (SSA_VAR_P (var)); + + is_real_op = is_gimple_reg (var); + + /* If this is a real operand, the operand is either an SSA name or a + decl. Virtual operands may only be decls. */ + gcc_assert (is_real_op || DECL_P (var)); + + sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); + v_ann = var_ann (sym); + + /* Mark statements with volatile operands. Optimizers should back + off from statements having volatile operands. */ + if (TREE_THIS_VOLATILE (sym) && s_ann) + s_ann->has_volatile_ops = true; + + if (is_real_op) + { + /* The variable is a GIMPLE register. Add it to real operands. */ + if (flags & opf_is_def) + append_def (var_p); + else + append_use (var_p); + } + else + add_virtual_operand (var, s_ann, flags, NULL_TREE, 0, -1, false); +} + + +/* A subroutine of get_expr_operands to handle INDIRECT_REF, + ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF. + + STMT is the statement being processed, EXPR is the INDIRECT_REF + that got us here. + + FLAGS is as in get_expr_operands. + + FULL_REF contains the full pointer dereference expression, if we + have it, or NULL otherwise. + + OFFSET and SIZE are the location of the access inside the + dereferenced pointer, if known. + + RECURSE_ON_BASE should be set to true if we want to continue + calling get_expr_operands on the base pointer, and false if + something else will do it for us. */ + +static void +get_indirect_ref_operands (tree stmt, tree expr, int flags, + tree full_ref, + HOST_WIDE_INT offset, HOST_WIDE_INT size, + bool recurse_on_base) +{ + tree *pptr = &TREE_OPERAND (expr, 0); + tree ptr = *pptr; + stmt_ann_t s_ann = stmt_ann (stmt); + + /* Stores into INDIRECT_REF operands are never killing definitions. */ + flags &= ~opf_kill_def; + + if (SSA_VAR_P (ptr)) + { + struct ptr_info_def *pi = NULL; + + /* If PTR has flow-sensitive points-to information, use it. */ + if (TREE_CODE (ptr) == SSA_NAME + && (pi = SSA_NAME_PTR_INFO (ptr)) != NULL + && pi->name_mem_tag) + { + /* PTR has its own memory tag. Use it. */ + add_virtual_operand (pi->name_mem_tag, s_ann, flags, + full_ref, offset, size, false); + } + else + { + /* If PTR is not an SSA_NAME or it doesn't have a name + tag, use its symbol memory tag. */ + var_ann_t v_ann; + + /* If we are emitting debugging dumps, display a warning if + PTR is an SSA_NAME with no flow-sensitive alias + information. That means that we may need to compute + aliasing again. */ + if (dump_file + && TREE_CODE (ptr) == SSA_NAME + && pi == NULL) + { + fprintf (dump_file, + "NOTE: no flow-sensitive alias info for "); + print_generic_expr (dump_file, ptr, dump_flags); + fprintf (dump_file, " in "); + print_generic_stmt (dump_file, stmt, dump_flags); + } + + if (TREE_CODE (ptr) == SSA_NAME) + ptr = SSA_NAME_VAR (ptr); + v_ann = var_ann (ptr); + + if (v_ann->symbol_mem_tag) + add_virtual_operand (v_ann->symbol_mem_tag, s_ann, flags, + full_ref, offset, size, false); + } + } + else if (TREE_CODE (ptr) == INTEGER_CST) + { + /* If a constant is used as a pointer, we can't generate a real + operand for it but we mark the statement volatile to prevent + optimizations from messing things up. */ + if (s_ann) + s_ann->has_volatile_ops = true; + return; + } + else + { + /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */ + gcc_unreachable (); + } + + /* If requested, add a USE operand for the base pointer. */ + if (recurse_on_base) + get_expr_operands (stmt, pptr, opf_none); +} + + +/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ + +static void +get_tmr_operands (tree stmt, tree expr, int flags) +{ + tree tag = TMR_TAG (expr), ref; + HOST_WIDE_INT offset, size, maxsize; + subvar_t svars, sv; + stmt_ann_t s_ann = stmt_ann (stmt); + + /* First record the real operands. */ + get_expr_operands (stmt, &TMR_BASE (expr), opf_none); + get_expr_operands (stmt, &TMR_INDEX (expr), opf_none); + + /* MEM_REFs should never be killing. */ + flags &= ~opf_kill_def; + + if (TMR_SYMBOL (expr)) + { + stmt_ann_t ann = stmt_ann (stmt); + add_to_addressable_set (TMR_SYMBOL (expr), &ann->addresses_taken); + } + + if (!tag) + { + /* Something weird, so ensure that we will be careful. */ + stmt_ann (stmt)->has_volatile_ops = true; + return; + } + + if (DECL_P (tag)) + { + get_expr_operands (stmt, &tag, flags); + return; + } + + ref = get_ref_base_and_extent (tag, &offset, &size, &maxsize); + gcc_assert (ref != NULL_TREE); + svars = get_subvars_for_var (ref); + for (sv = svars; sv; sv = sv->next) + { + bool exact; + if (overlap_subvar (offset, maxsize, sv->var, &exact)) + { + int subvar_flags = flags; + if (!exact || size != maxsize) + subvar_flags &= ~opf_kill_def; + add_stmt_operand (&sv->var, s_ann, subvar_flags); + } + } +} + + +/* Add clobbering definitions for .GLOBAL_VAR or for each of the call + clobbered variables in the function. */ + +static void +add_call_clobber_ops (tree stmt, tree callee) +{ + unsigned u; + bitmap_iterator bi; + stmt_ann_t s_ann = stmt_ann (stmt); + bitmap not_read_b, not_written_b; + + /* Functions that are not const, pure or never return may clobber + call-clobbered variables. */ + if (s_ann) + s_ann->makes_clobbering_call = true; + + /* If we created .GLOBAL_VAR earlier, just use it. See compute_may_aliases + for the heuristic used to decide whether to create .GLOBAL_VAR or not. */ + if (global_var) + { + add_stmt_operand (&global_var, s_ann, opf_is_def); + return; + } + + /* Get info for local and module level statics. There is a bit + set for each static if the call being processed does not read + or write that variable. */ + not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL; + not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL; + /* Add a V_MAY_DEF operand for every call clobbered variable. */ + EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi) + { + tree var = referenced_var_lookup (u); + unsigned int escape_mask = var_ann (var)->escape_mask; + tree real_var = var; + bool not_read; + bool not_written; + + /* Not read and not written are computed on regular vars, not + subvars, so look at the parent var if this is an SFT. */ + if (TREE_CODE (var) == STRUCT_FIELD_TAG) + real_var = SFT_PARENT_VAR (var); + + not_read = not_read_b ? bitmap_bit_p (not_read_b, + DECL_UID (real_var)) : false; + not_written = not_written_b ? bitmap_bit_p (not_written_b, + DECL_UID (real_var)) : false; + gcc_assert (!unmodifiable_var_p (var)); + + clobber_stats.clobbered_vars++; + + /* See if this variable is really clobbered by this function. */ + + /* Trivial case: Things escaping only to pure/const are not + clobbered by non-pure-const, and only read by pure/const. */ + if ((escape_mask & ~(ESCAPE_TO_PURE_CONST)) == 0) + { + tree call = get_call_expr_in (stmt); + if (call_expr_flags (call) & (ECF_CONST | ECF_PURE)) + { + add_stmt_operand (&var, s_ann, opf_none); + clobber_stats.unescapable_clobbers_avoided++; + continue; + } + else + { + clobber_stats.unescapable_clobbers_avoided++; + continue; + } + } + + if (not_written) + { + clobber_stats.static_write_clobbers_avoided++; + if (!not_read) + add_stmt_operand (&var, s_ann, opf_none); + else + clobber_stats.static_read_clobbers_avoided++; + } + else + add_virtual_operand (var, s_ann, opf_is_def, NULL, 0, -1, true); + } +} + + +/* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the + function. */ + +static void +add_call_read_ops (tree stmt, tree callee) +{ + unsigned u; + bitmap_iterator bi; + stmt_ann_t s_ann = stmt_ann (stmt); + bitmap not_read_b; + + /* if the function is not pure, it may reference memory. Add + a VUSE for .GLOBAL_VAR if it has been created. See add_referenced_var + for the heuristic used to decide whether to create .GLOBAL_VAR. */ + if (global_var) + { + add_stmt_operand (&global_var, s_ann, opf_none); + return; + } + + not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL; + + /* Add a VUSE for each call-clobbered variable. */ + EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, u, bi) + { + tree var = referenced_var (u); + tree real_var = var; + bool not_read; + + clobber_stats.readonly_clobbers++; + + /* Not read and not written are computed on regular vars, not + subvars, so look at the parent var if this is an SFT. */ + + if (TREE_CODE (var) == STRUCT_FIELD_TAG) + real_var = SFT_PARENT_VAR (var); + + not_read = not_read_b ? bitmap_bit_p (not_read_b, DECL_UID (real_var)) + : false; + + if (not_read) + { + clobber_stats.static_readonly_clobbers_avoided++; + continue; + } + + add_stmt_operand (&var, s_ann, opf_none | opf_non_specific); + } +} + + +/* A subroutine of get_expr_operands to handle CALL_EXPR. */ + +static void +get_call_expr_operands (tree stmt, tree expr) +{ + tree op; + int call_flags = call_expr_flags (expr); + + /* If aliases have been computed already, add V_MAY_DEF or V_USE + operands for all the symbols that have been found to be + call-clobbered. + + Note that if aliases have not been computed, the global effects + of calls will not be included in the SSA web. This is fine + because no optimizer should run before aliases have been + computed. By not bothering with virtual operands for CALL_EXPRs + we avoid adding superfluous virtual operands, which can be a + significant compile time sink (See PR 15855). */ + if (aliases_computed_p + && !bitmap_empty_p (call_clobbered_vars) + && !(call_flags & ECF_NOVOPS)) + { + /* A 'pure' or a 'const' function never call-clobbers anything. + A 'noreturn' function might, but since we don't return anyway + there is no point in recording that. */ + if (TREE_SIDE_EFFECTS (expr) + && !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN))) + add_call_clobber_ops (stmt, get_callee_fndecl (expr)); + else if (!(call_flags & ECF_CONST)) + add_call_read_ops (stmt, get_callee_fndecl (expr)); + } + + /* Find uses in the called function. */ + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none); + + for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op)) + get_expr_operands (stmt, &TREE_VALUE (op), opf_none); + + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); +} + + +/* Scan operands in the ASM_EXPR stmt referred to in INFO. */ + +static void +get_asm_expr_operands (tree stmt) +{ + stmt_ann_t s_ann = stmt_ann (stmt); + int noutputs = list_length (ASM_OUTPUTS (stmt)); + const char **oconstraints + = (const char **) alloca ((noutputs) * sizeof (const char *)); + int i; + tree link; + const char *constraint; + bool allows_mem, allows_reg, is_inout; + + for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link)) + { + constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); + oconstraints[i] = constraint; + parse_output_constraint (&constraint, i, 0, 0, &allows_mem, + &allows_reg, &is_inout); + + /* This should have been split in gimplify_asm_expr. */ + gcc_assert (!allows_reg || !is_inout); + + /* Memory operands are addressable. Note that STMT needs the + address of this operand. */ + if (!allows_reg && allows_mem) + { + tree t = get_base_address (TREE_VALUE (link)); + if (t && DECL_P (t) && s_ann) + add_to_addressable_set (t, &s_ann->addresses_taken); + } + + get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def); + } + + for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link)) + { + constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); + parse_input_constraint (&constraint, 0, 0, noutputs, 0, + oconstraints, &allows_mem, &allows_reg); + + /* Memory operands are addressable. Note that STMT needs the + address of this operand. */ + if (!allows_reg && allows_mem) + { + tree t = get_base_address (TREE_VALUE (link)); + if (t && DECL_P (t) && s_ann) + add_to_addressable_set (t, &s_ann->addresses_taken); + } + + get_expr_operands (stmt, &TREE_VALUE (link), 0); + } + + + /* Clobber memory for asm ("" : : : "memory"); */ + for (link = ASM_CLOBBERS (stmt); link; link = TREE_CHAIN (link)) + if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0) + { + unsigned i; + bitmap_iterator bi; + + /* Clobber all call-clobbered variables (or .GLOBAL_VAR if we + decided to group them). */ + if (global_var) + add_stmt_operand (&global_var, s_ann, opf_is_def); + else + EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi) + { + tree var = referenced_var (i); + add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific); + } + + /* Now clobber all addressables. */ + EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi) + { + tree var = referenced_var (i); + + /* Subvars are explicitly represented in this list, so + we don't need the original to be added to the clobber + ops, but the original *will* be in this list because + we keep the addressability of the original + variable up-to-date so we don't screw up the rest of + the backend. */ + if (var_can_have_subvars (var) + && get_subvars_for_var (var) != NULL) + continue; + + add_stmt_operand (&var, s_ann, opf_is_def | opf_non_specific); + } + + break; + } +} + + +/* Scan operands for the assignment expression EXPR in statement STMT. */ + +static void +get_modify_expr_operands (tree stmt, tree expr) +{ + /* First get operands from the RHS. */ + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); + + /* For the LHS, use a regular definition (OPF_IS_DEF) for GIMPLE + registers. If the LHS is a store to memory, we will either need + a preserving definition (V_MAY_DEF) or a killing definition + (V_MUST_DEF). + + Preserving definitions are those that modify a part of an + aggregate object for which no subvars have been computed (or the + reference does not correspond exactly to one of them). Stores + through a pointer are also represented with V_MAY_DEF operators. + + The determination of whether to use a preserving or a killing + definition is done while scanning the LHS of the assignment. By + default, assume that we will emit a V_MUST_DEF. */ + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_is_def|opf_kill_def); +} + + +/* Recursively scan the expression pointed to by EXPR_P in statement + STMT. FLAGS is one of the OPF_* constants modifying how to + interpret the operands found. */ + +static void +get_expr_operands (tree stmt, tree *expr_p, int flags) +{ + enum tree_code code; + enum tree_code_class class; + tree expr = *expr_p; + stmt_ann_t s_ann = stmt_ann (stmt); + + if (expr == NULL) + return; + + code = TREE_CODE (expr); + class = TREE_CODE_CLASS (code); + + switch (code) + { + case ADDR_EXPR: + /* Taking the address of a variable does not represent a + reference to it, but the fact that the statement takes its + address will be of interest to some passes (e.g. alias + resolution). */ + add_to_addressable_set (TREE_OPERAND (expr, 0), &s_ann->addresses_taken); + + /* If the address is invariant, there may be no interesting + variable references inside. */ + if (is_gimple_min_invariant (expr)) + return; + + /* Otherwise, there may be variables referenced inside but there + should be no VUSEs created, since the referenced objects are + not really accessed. The only operands that we should find + here are ARRAY_REF indices which will always be real operands + (GIMPLE does not allow non-registers as array indices). */ + flags |= opf_no_vops; + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + return; + + case SSA_NAME: + case STRUCT_FIELD_TAG: + case SYMBOL_MEMORY_TAG: + case NAME_MEMORY_TAG: + add_stmt_operand (expr_p, s_ann, flags); + return; + + case VAR_DECL: + case PARM_DECL: + case RESULT_DECL: + { + subvar_t svars; + + /* Add the subvars for a variable, if it has subvars, to DEFS + or USES. Otherwise, add the variable itself. Whether it + goes to USES or DEFS depends on the operand flags. */ + if (var_can_have_subvars (expr) + && (svars = get_subvars_for_var (expr))) + { + subvar_t sv; + for (sv = svars; sv; sv = sv->next) + add_stmt_operand (&sv->var, s_ann, flags); + } + else + add_stmt_operand (expr_p, s_ann, flags); + + return; + } + + case MISALIGNED_INDIRECT_REF: + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags); + /* fall through */ + + case ALIGN_INDIRECT_REF: + case INDIRECT_REF: + get_indirect_ref_operands (stmt, expr, flags, NULL_TREE, 0, -1, true); + return; + + case TARGET_MEM_REF: + get_tmr_operands (stmt, expr, flags); + return; + + case ARRAY_REF: + case ARRAY_RANGE_REF: + case COMPONENT_REF: + case REALPART_EXPR: + case IMAGPART_EXPR: + { + tree ref; + HOST_WIDE_INT offset, size, maxsize; + bool none = true; + + /* This component reference becomes an access to all of the + subvariables it can touch, if we can determine that, but + *NOT* the real one. If we can't determine which fields we + could touch, the recursion will eventually get to a + variable and add *all* of its subvars, or whatever is the + minimum correct subset. */ + ref = get_ref_base_and_extent (expr, &offset, &size, &maxsize); + if (SSA_VAR_P (ref) && get_subvars_for_var (ref)) + { + subvar_t sv; + subvar_t svars = get_subvars_for_var (ref); + + for (sv = svars; sv; sv = sv->next) + { + bool exact; + + if (overlap_subvar (offset, maxsize, sv->var, &exact)) + { + int subvar_flags = flags; + none = false; + if (!exact || size != maxsize) + subvar_flags &= ~opf_kill_def; + add_stmt_operand (&sv->var, s_ann, subvar_flags); + } + } + + if (!none) + flags |= opf_no_vops; + } + else if (TREE_CODE (ref) == INDIRECT_REF) + { + get_indirect_ref_operands (stmt, ref, flags, expr, offset, + maxsize, false); + flags |= opf_no_vops; + } + + /* Even if we found subvars above we need to ensure to see + immediate uses for d in s.a[d]. In case of s.a having + a subvar or we would miss it otherwise. */ + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), + flags & ~opf_kill_def); + + if (code == COMPONENT_REF) + { + if (s_ann && TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1))) + s_ann->has_volatile_ops = true; + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); + } + else if (code == ARRAY_REF || code == ARRAY_RANGE_REF) + { + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); + get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_none); + } + + return; + } + + case WITH_SIZE_EXPR: + /* WITH_SIZE_EXPR is a pass-through reference to its first argument, + and an rvalue reference to its second argument. */ + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + return; + + case CALL_EXPR: + get_call_expr_operands (stmt, expr); + return; + + case COND_EXPR: + case VEC_COND_EXPR: + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none); + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); + return; + + case MODIFY_EXPR: + get_modify_expr_operands (stmt, expr); + return; + + case CONSTRUCTOR: + { + /* General aggregate CONSTRUCTORs have been decomposed, but they + are still in use as the COMPLEX_EXPR equivalent for vectors. */ + constructor_elt *ce; + unsigned HOST_WIDE_INT idx; + + for (idx = 0; + VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce); + idx++) + get_expr_operands (stmt, &ce->value, opf_none); + + return; + } + + case BIT_FIELD_REF: + /* Stores using BIT_FIELD_REF are always preserving definitions. */ + flags &= ~opf_kill_def; + + /* Fallthru */ + + case TRUTH_NOT_EXPR: + case VIEW_CONVERT_EXPR: + do_unary: + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + return; + + case TRUTH_AND_EXPR: + case TRUTH_OR_EXPR: + case TRUTH_XOR_EXPR: + case COMPOUND_EXPR: + case OBJ_TYPE_REF: + case ASSERT_EXPR: + do_binary: + { + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags); + return; + } + + case DOT_PROD_EXPR: + case REALIGN_LOAD_EXPR: + { + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), flags); + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), flags); + return; + } + + case BLOCK: + case FUNCTION_DECL: + case EXC_PTR_EXPR: + case FILTER_EXPR: + case LABEL_DECL: + case CONST_DECL: + case OMP_PARALLEL: + case OMP_SECTIONS: + case OMP_FOR: + case OMP_SINGLE: + case OMP_MASTER: + case OMP_ORDERED: + case OMP_CRITICAL: + case OMP_RETURN: + case OMP_CONTINUE: + /* Expressions that make no memory references. */ + return; + + default: + if (class == tcc_unary) + goto do_unary; + if (class == tcc_binary || class == tcc_comparison) + goto do_binary; + if (class == tcc_constant || class == tcc_type) + return; + } + + /* If we get here, something has gone wrong. */ +#ifdef ENABLE_CHECKING + fprintf (stderr, "unhandled expression in get_expr_operands():\n"); + debug_tree (expr); + fputs ("\n", stderr); +#endif + gcc_unreachable (); +} + + +/* Parse STMT looking for operands. When finished, the various + build_* operand vectors will have potential operands in them. */ + +static void +parse_ssa_operands (tree stmt) +{ + enum tree_code code; + + code = TREE_CODE (stmt); + switch (code) + { + case MODIFY_EXPR: + get_modify_expr_operands (stmt, stmt); + break; + + case COND_EXPR: + get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none); + break; + + case SWITCH_EXPR: + get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none); + break; + + case ASM_EXPR: + get_asm_expr_operands (stmt); + break; + + case RETURN_EXPR: + get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_none); + break; + + case GOTO_EXPR: + get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_none); + break; + + case LABEL_EXPR: + get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none); + break; + + case BIND_EXPR: + case CASE_LABEL_EXPR: + case TRY_CATCH_EXPR: + case TRY_FINALLY_EXPR: + case EH_FILTER_EXPR: + case CATCH_EXPR: + case RESX_EXPR: + /* These nodes contain no variable references. */ + break; + + default: + /* Notice that if get_expr_operands tries to use &STMT as the + operand pointer (which may only happen for USE operands), we + will fail in add_stmt_operand. This default will handle + statements like empty statements, or CALL_EXPRs that may + appear on the RHS of a statement or as statements themselves. */ + get_expr_operands (stmt, &stmt, opf_none); + break; + } +} + + +/* Create an operands cache for STMT. */ + +static void +build_ssa_operands (tree stmt) +{ + stmt_ann_t ann = get_stmt_ann (stmt); + + /* Initially assume that the statement has no volatile operands and + does not take the address of any symbols. */ + if (ann) + { + ann->has_volatile_ops = false; + if (ann->addresses_taken) + ann->addresses_taken = NULL; + } + + start_ssa_stmt_operands (); + + parse_ssa_operands (stmt); + operand_build_sort_virtual (build_vuses); + operand_build_sort_virtual (build_v_may_defs); + operand_build_sort_virtual (build_v_must_defs); + + finalize_ssa_stmt_operands (stmt); +} + + +/* Free any operands vectors in OPS. */ + +void +free_ssa_operands (stmt_operands_p ops) +{ + ops->def_ops = NULL; + ops->use_ops = NULL; + ops->maydef_ops = NULL; + ops->mustdef_ops = NULL; + ops->vuse_ops = NULL; +} + + +/* Get the operands of statement STMT. */ + +void +update_stmt_operands (tree stmt) +{ + stmt_ann_t ann = get_stmt_ann (stmt); + + /* If update_stmt_operands is called before SSA is initialized, do + nothing. */ + if (!ssa_operands_active ()) + return; + + /* The optimizers cannot handle statements that are nothing but a + _DECL. This indicates a bug in the gimplifier. */ + gcc_assert (!SSA_VAR_P (stmt)); + + gcc_assert (ann->modified); + + timevar_push (TV_TREE_OPS); + + build_ssa_operands (stmt); + + /* Clear the modified bit for STMT. */ + ann->modified = 0; + + timevar_pop (TV_TREE_OPS); +} + + +/* Copies virtual operands from SRC to DST. */ + +void +copy_virtual_operands (tree dest, tree src) +{ + tree t; + ssa_op_iter iter, old_iter; + use_operand_p use_p, u2; + def_operand_p def_p, d2; + + build_ssa_operands (dest); + + /* Copy all the virtual fields. */ + FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VUSE) + append_vuse (t); + FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMAYDEF) + append_v_may_def (t); + FOR_EACH_SSA_TREE_OPERAND (t, src, iter, SSA_OP_VMUSTDEF) + append_v_must_def (t); + + if (VEC_length (tree, build_vuses) == 0 + && VEC_length (tree, build_v_may_defs) == 0 + && VEC_length (tree, build_v_must_defs) == 0) + return; + + /* Now commit the virtual operands to this stmt. */ + finalize_ssa_v_must_defs (dest); + finalize_ssa_v_may_defs (dest); + finalize_ssa_vuses (dest); + + /* Finally, set the field to the same values as then originals. */ + t = op_iter_init_tree (&old_iter, src, SSA_OP_VUSE); + FOR_EACH_SSA_USE_OPERAND (use_p, dest, iter, SSA_OP_VUSE) + { + gcc_assert (!op_iter_done (&old_iter)); + SET_USE (use_p, t); + t = op_iter_next_tree (&old_iter); + } + gcc_assert (op_iter_done (&old_iter)); + + op_iter_init_maydef (&old_iter, src, &u2, &d2); + FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, dest, iter) + { + gcc_assert (!op_iter_done (&old_iter)); + SET_USE (use_p, USE_FROM_PTR (u2)); + SET_DEF (def_p, DEF_FROM_PTR (d2)); + op_iter_next_maymustdef (&u2, &d2, &old_iter); + } + gcc_assert (op_iter_done (&old_iter)); + + op_iter_init_mustdef (&old_iter, src, &u2, &d2); + FOR_EACH_SSA_MUSTDEF_OPERAND (def_p, use_p, dest, iter) + { + gcc_assert (!op_iter_done (&old_iter)); + SET_USE (use_p, USE_FROM_PTR (u2)); + SET_DEF (def_p, DEF_FROM_PTR (d2)); + op_iter_next_maymustdef (&u2, &d2, &old_iter); + } + gcc_assert (op_iter_done (&old_iter)); + +} + + +/* Specifically for use in DOM's expression analysis. Given a store, we + create an artificial stmt which looks like a load from the store, this can + be used to eliminate redundant loads. OLD_OPS are the operands from the + store stmt, and NEW_STMT is the new load which represents a load of the + values stored. */ + +void +create_ssa_artficial_load_stmt (tree new_stmt, tree old_stmt) +{ + stmt_ann_t ann; + tree op; + ssa_op_iter iter; + use_operand_p use_p; + unsigned x; + + ann = get_stmt_ann (new_stmt); + + /* Process the stmt looking for operands. */ + start_ssa_stmt_operands (); + parse_ssa_operands (new_stmt); + + for (x = 0; x < VEC_length (tree, build_vuses); x++) + { + tree t = VEC_index (tree, build_vuses, x); + if (TREE_CODE (t) != SSA_NAME) + { + var_ann_t ann = var_ann (t); + ann->in_vuse_list = 0; + } + } + + for (x = 0; x < VEC_length (tree, build_v_may_defs); x++) + { + tree t = VEC_index (tree, build_v_may_defs, x); + if (TREE_CODE (t) != SSA_NAME) + { + var_ann_t ann = var_ann (t); + ann->in_v_may_def_list = 0; + } + } + + /* Remove any virtual operands that were found. */ + VEC_truncate (tree, build_v_may_defs, 0); + VEC_truncate (tree, build_v_must_defs, 0); + VEC_truncate (tree, build_vuses, 0); + + /* For each VDEF on the original statement, we want to create a + VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new + statement. */ + FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter, + (SSA_OP_VMAYDEF | SSA_OP_VMUSTDEF)) + append_vuse (op); + + /* Now build the operands for this new stmt. */ + finalize_ssa_stmt_operands (new_stmt); + + /* All uses in this fake stmt must not be in the immediate use lists. */ + FOR_EACH_SSA_USE_OPERAND (use_p, new_stmt, iter, SSA_OP_ALL_USES) + delink_imm_use (use_p); +} + + +/* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done + to test the validity of the swap operation. */ + +void +swap_tree_operands (tree stmt, tree *exp0, tree *exp1) +{ + tree op0, op1; + op0 = *exp0; + op1 = *exp1; + + /* If the operand cache is active, attempt to preserve the relative + positions of these two operands in their respective immediate use + lists. */ + if (ssa_operands_active () && op0 != op1) + { + use_optype_p use0, use1, ptr; + use0 = use1 = NULL; + + /* Find the 2 operands in the cache, if they are there. */ + for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next) + if (USE_OP_PTR (ptr)->use == exp0) + { + use0 = ptr; + break; + } + + for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next) + if (USE_OP_PTR (ptr)->use == exp1) + { + use1 = ptr; + break; + } + + /* If both uses don't have operand entries, there isn't much we can do + at this point. Presumably we don't need to worry about it. */ + if (use0 && use1) + { + tree *tmp = USE_OP_PTR (use1)->use; + USE_OP_PTR (use1)->use = USE_OP_PTR (use0)->use; + USE_OP_PTR (use0)->use = tmp; + } + } + + /* Now swap the data. */ + *exp0 = op1; + *exp1 = op0; +} + + +/* Add the base address of REF to the set *ADDRESSES_TAKEN. If + *ADDRESSES_TAKEN is NULL, a new set is created. REF may be + a single variable whose address has been taken or any other valid + GIMPLE memory reference (structure reference, array, etc). If the + base address of REF is a decl that has sub-variables, also add all + of its sub-variables. */ + +void +add_to_addressable_set (tree ref, bitmap *addresses_taken) +{ + tree var; + subvar_t svars; + + gcc_assert (addresses_taken); + + /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF + as the only thing we take the address of. If VAR is a structure, + taking the address of a field means that the whole structure may + be referenced using pointer arithmetic. See PR 21407 and the + ensuing mailing list discussion. */ + var = get_base_address (ref); + if (var && SSA_VAR_P (var)) + { + if (*addresses_taken == NULL) + *addresses_taken = BITMAP_GGC_ALLOC (); + + if (var_can_have_subvars (var) + && (svars = get_subvars_for_var (var))) + { + subvar_t sv; + for (sv = svars; sv; sv = sv->next) + { + bitmap_set_bit (*addresses_taken, DECL_UID (sv->var)); + TREE_ADDRESSABLE (sv->var) = 1; + } + } + else + { + bitmap_set_bit (*addresses_taken, DECL_UID (var)); + TREE_ADDRESSABLE (var) = 1; + } + } +} + + +/* Scan the immediate_use list for VAR making sure its linked properly. + Return TRUE if there is a problem and emit an error message to F. */ + +bool +verify_imm_links (FILE *f, tree var) +{ + use_operand_p ptr, prev, list; + int count; + + gcc_assert (TREE_CODE (var) == SSA_NAME); + + list = &(SSA_NAME_IMM_USE_NODE (var)); + gcc_assert (list->use == NULL); + + if (list->prev == NULL) + { + gcc_assert (list->next == NULL); + return false; + } + + prev = list; + count = 0; + for (ptr = list->next; ptr != list; ) + { + if (prev != ptr->prev) + goto error; + + if (ptr->use == NULL) + goto error; /* 2 roots, or SAFE guard node. */ + else if (*(ptr->use) != var) + goto error; + + prev = ptr; + ptr = ptr->next; + + /* Avoid infinite loops. 50,000,000 uses probably indicates a + problem. */ + if (count++ > 50000000) + goto error; + } + + /* Verify list in the other direction. */ + prev = list; + for (ptr = list->prev; ptr != list; ) + { + if (prev != ptr->next) + goto error; + prev = ptr; + ptr = ptr->prev; + if (count-- < 0) + goto error; + } + + if (count != 0) + goto error; + + return false; + + error: + if (ptr->stmt && stmt_modified_p (ptr->stmt)) + { + fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->stmt); + print_generic_stmt (f, ptr->stmt, TDF_SLIM); + } + fprintf (f, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr, + (void *)ptr->use); + print_generic_expr (f, USE_FROM_PTR (ptr), TDF_SLIM); + fprintf(f, "\n"); + return true; +} + + +/* Dump all the immediate uses to FILE. */ + +void +dump_immediate_uses_for (FILE *file, tree var) +{ + imm_use_iterator iter; + use_operand_p use_p; + + gcc_assert (var && TREE_CODE (var) == SSA_NAME); + + print_generic_expr (file, var, TDF_SLIM); + fprintf (file, " : -->"); + if (has_zero_uses (var)) + fprintf (file, " no uses.\n"); + else + if (has_single_use (var)) + fprintf (file, " single use.\n"); + else + fprintf (file, "%d uses.\n", num_imm_uses (var)); + + FOR_EACH_IMM_USE_FAST (use_p, iter, var) + { + if (use_p->stmt == NULL && use_p->use == NULL) + fprintf (file, "***end of stmt iterator marker***\n"); + else + if (!is_gimple_reg (USE_FROM_PTR (use_p))) + print_generic_stmt (file, USE_STMT (use_p), TDF_VOPS); + else + print_generic_stmt (file, USE_STMT (use_p), TDF_SLIM); + } + fprintf(file, "\n"); +} + + +/* Dump all the immediate uses to FILE. */ + +void +dump_immediate_uses (FILE *file) +{ + tree var; + unsigned int x; + + fprintf (file, "Immediate_uses: \n\n"); + for (x = 1; x < num_ssa_names; x++) + { + var = ssa_name(x); + if (!var) + continue; + dump_immediate_uses_for (file, var); + } +} + + +/* Dump def-use edges on stderr. */ + +void +debug_immediate_uses (void) +{ + dump_immediate_uses (stderr); +} + + +/* Dump def-use edges on stderr. */ + +void +debug_immediate_uses_for (tree var) +{ + dump_immediate_uses_for (stderr, var); +} + +#include "gt-tree-ssa-operands.h" |