| /* 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" |