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Diffstat (limited to 'gcc-4.4.3/gcc/tree-ssa-operands.c')
| -rw-r--r-- | gcc-4.4.3/gcc/tree-ssa-operands.c | 2745 |
1 files changed, 2745 insertions, 0 deletions
diff --git a/gcc-4.4.3/gcc/tree-ssa-operands.c b/gcc-4.4.3/gcc/tree-ssa-operands.c new file mode 100644 index 000000000..a762f5f9b --- /dev/null +++ b/gcc-4.4.3/gcc/tree-ssa-operands.c @@ -0,0 +1,2745 @@ +/* SSA operands management for trees. + Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 + Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "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 4 of these routines, each representing one of the + 4 types of operands. Defs, Uses, Virtual Uses, and Virtual May 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 4 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'. */ + +/* Helper functions from gimple.c. These are GIMPLE manipulation + routines that only the operand scanner should need. */ +void gimple_set_stored_syms (gimple, bitmap, bitmap_obstack *); +void gimple_set_loaded_syms (gimple, bitmap, bitmap_obstack *); + +/* 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_clobbered_mem_symbols. */ + unsigned int clobbered_vars; + + /* Number of write-clobbers (VDEFs) 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_mem_symbols. */ + unsigned int readonly_clobbers; + + /* Number of read-only uses we avoid using not_read information. */ + unsigned int static_readonly_clobbers_avoided; +} clobber_stats; + + +/* Flags to describe operand properties in helpers. */ + +/* By default, operands are loaded. */ +#define opf_use 0 + +/* Operand is the target of an assignment expression or a + call-clobbered variable. */ +#define opf_def (1 << 0) + +/* 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 << 1) + +/* Operand is an implicit reference. This is used to distinguish + explicit assignments in the form of MODIFY_EXPR from + clobbering sites like function calls or ASM_EXPRs. */ +#define opf_implicit (1 << 2) + +/* 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; + +/* Set for building all the VDEF operands. */ +static VEC(tree,heap) *build_vdefs; + +/* Set for building all the VUSE operands. */ +static VEC(tree,heap) *build_vuses; + +/* Bitmap obstack for our datastructures that needs to survive across + compilations of multiple functions. */ +static bitmap_obstack operands_bitmap_obstack; + +/* Set for building all the loaded symbols. */ +static bitmap build_loads; + +/* Set for building all the stored symbols. */ +static bitmap build_stores; + +static void get_expr_operands (gimple, tree *, int); + +/* Number of functions with initialized ssa_operands. */ +static int n_initialized = 0; + +/* Statement change buffer. Data structure used to record state + information for statements. This is used to determine what needs + to be done in order to update the SSA web after a statement is + modified by a pass. If STMT is a statement that has just been + created, or needs to be folded via fold_stmt, or anything that + changes its physical structure then the pass should: + + 1- Call push_stmt_changes (&stmt) to record the current state of + STMT before any modifications are made. + + 2- Make all appropriate modifications to the statement. + + 3- Call pop_stmt_changes (&stmt) to find new symbols that + need to be put in SSA form, SSA name mappings for names that + have disappeared, recompute invariantness for address + expressions, cleanup EH information, etc. + + If it is possible to determine that the statement was not modified, + instead of calling pop_stmt_changes it is quicker to call + discard_stmt_changes to avoid the expensive and unnecessary operand + re-scan and change comparison. */ + +struct scb_d +{ + /* Pointer to the statement being modified. */ + gimple *stmt_p; + + /* If the statement references memory these are the sets of symbols + loaded and stored by the statement. */ + bitmap loads; + bitmap stores; +}; + +typedef struct scb_d *scb_t; +DEF_VEC_P(scb_t); +DEF_VEC_ALLOC_P(scb_t,heap); + +/* Stack of statement change buffers (SCB). Every call to + push_stmt_changes pushes a new buffer onto the stack. Calls to + pop_stmt_changes pop a buffer off of the stack and compute the set + of changes for the popped statement. */ +static VEC(scb_t,heap) *scb_stack; + +/* Return the DECL_UID of the base variable of T. */ + +static inline unsigned +get_name_decl (const_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. */ + +int +operand_build_cmp (const void *p, const void *q) +{ + const_tree const e1 = *((const_tree const *)p); + const_tree const e2 = *((const_tree const *)q); + const unsigned int u1 = get_name_decl (e1); + const unsigned int 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) +{ + /* This function may be invoked from contexts where CFUN is NULL + (IPA passes), return false for now. FIXME: operands may be + active in each individual function, maybe this function should + take CFUN as a parameter. */ + if (cfun == NULL) + return false; + + return cfun->gimple_df && gimple_ssa_operands (cfun)->ops_active; +} + + +/* VOPs are of variable sized, so the free list maps "free buckets" to the + following table: + bucket # operands + ------ ---------- + 0 1 + 1 2 + ... + 15 16 + 16 17-24 + 17 25-32 + 18 31-40 + ... + 29 121-128 + Any VOPs larger than this are simply added to the largest bucket when they + are freed. */ + + +/* Return the number of operands used in bucket BUCKET. */ + +static inline int +vop_free_bucket_size (int bucket) +{ +#ifdef ENABLE_CHECKING + gcc_assert (bucket >= 0 && bucket < NUM_VOP_FREE_BUCKETS); +#endif + if (bucket < 16) + return bucket + 1; + return (bucket - 13) * 8; +} + + +/* For a vop of NUM operands, return the bucket NUM belongs to. If NUM is + beyond the end of the bucket table, return -1. */ + +static inline int +vop_free_bucket_index (int num) +{ + gcc_assert (num > 0 && NUM_VOP_FREE_BUCKETS > 16); + + /* Sizes 1 through 16 use buckets 0-15. */ + if (num <= 16) + return num - 1; + /* Buckets 16 - NUM_VOP_FREE_BUCKETS represent 8 unit chunks. */ + num = 14 + (num - 1) / 8; + if (num >= NUM_VOP_FREE_BUCKETS) + return -1; + else + return num; +} + + +/* Initialize the VOP free buckets. */ + +static inline void +init_vop_buckets (void) +{ + int x; + + for (x = 0; x < NUM_VOP_FREE_BUCKETS; x++) + gimple_ssa_operands (cfun)->vop_free_buckets[x] = NULL; +} + + +/* Add PTR to the appropriate VOP bucket. */ + +static inline void +add_vop_to_freelist (voptype_p ptr) +{ + int bucket = vop_free_bucket_index (VUSE_VECT_NUM_ELEM (ptr->usev)); + + /* Too large, use the largest bucket so its not a complete throw away. */ + if (bucket == -1) + bucket = NUM_VOP_FREE_BUCKETS - 1; + + ptr->next = gimple_ssa_operands (cfun)->vop_free_buckets[bucket]; + gimple_ssa_operands (cfun)->vop_free_buckets[bucket] = ptr; +} + + +/* These are the sizes of the operand memory buffer which gets allocated each + time more operands space is required. The final value is the amount that is + allocated every time after that. */ + +#define OP_SIZE_INIT 0 +#define OP_SIZE_1 30 +#define OP_SIZE_2 110 +#define OP_SIZE_3 511 + +/* Initialize the operand cache routines. */ + +void +init_ssa_operands (void) +{ + if (!n_initialized++) + { + build_defs = VEC_alloc (tree, heap, 5); + build_uses = VEC_alloc (tree, heap, 10); + build_vuses = VEC_alloc (tree, heap, 25); + build_vdefs = VEC_alloc (tree, heap, 25); + bitmap_obstack_initialize (&operands_bitmap_obstack); + build_loads = BITMAP_ALLOC (&operands_bitmap_obstack); + build_stores = BITMAP_ALLOC (&operands_bitmap_obstack); + scb_stack = VEC_alloc (scb_t, heap, 20); + } + + gcc_assert (gimple_ssa_operands (cfun)->operand_memory == NULL); + gcc_assert (gimple_ssa_operands (cfun)->mpt_table == NULL); + gimple_ssa_operands (cfun)->operand_memory_index + = gimple_ssa_operands (cfun)->ssa_operand_mem_size; + gimple_ssa_operands (cfun)->ops_active = true; + memset (&clobber_stats, 0, sizeof (clobber_stats)); + init_vop_buckets (); + gimple_ssa_operands (cfun)->ssa_operand_mem_size = OP_SIZE_INIT; +} + + +/* Dispose of anything required by the operand routines. */ + +void +fini_ssa_operands (void) +{ + struct ssa_operand_memory_d *ptr; + unsigned ix; + tree mpt; + + if (!--n_initialized) + { + VEC_free (tree, heap, build_defs); + VEC_free (tree, heap, build_uses); + VEC_free (tree, heap, build_vdefs); + VEC_free (tree, heap, build_vuses); + BITMAP_FREE (build_loads); + BITMAP_FREE (build_stores); + + /* The change buffer stack had better be empty. */ + gcc_assert (VEC_length (scb_t, scb_stack) == 0); + VEC_free (scb_t, heap, scb_stack); + scb_stack = NULL; + } + + gimple_ssa_operands (cfun)->free_defs = NULL; + gimple_ssa_operands (cfun)->free_uses = NULL; + + while ((ptr = gimple_ssa_operands (cfun)->operand_memory) != NULL) + { + gimple_ssa_operands (cfun)->operand_memory + = gimple_ssa_operands (cfun)->operand_memory->next; + ggc_free (ptr); + } + + for (ix = 0; + VEC_iterate (tree, gimple_ssa_operands (cfun)->mpt_table, ix, mpt); + ix++) + { + if (mpt) + BITMAP_FREE (MPT_SYMBOLS (mpt)); + } + + VEC_free (tree, heap, gimple_ssa_operands (cfun)->mpt_table); + + gimple_ssa_operands (cfun)->ops_active = false; + + if (!n_initialized) + bitmap_obstack_release (&operands_bitmap_obstack); + + 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 (gimple_ssa_operands (cfun)->operand_memory_index + size + >= gimple_ssa_operands (cfun)->ssa_operand_mem_size) + { + struct ssa_operand_memory_d *ptr; + + if (gimple_ssa_operands (cfun)->ssa_operand_mem_size == OP_SIZE_INIT) + gimple_ssa_operands (cfun)->ssa_operand_mem_size + = OP_SIZE_1 * sizeof (struct voptype_d); + else + if (gimple_ssa_operands (cfun)->ssa_operand_mem_size + == OP_SIZE_1 * sizeof (struct voptype_d)) + gimple_ssa_operands (cfun)->ssa_operand_mem_size + = OP_SIZE_2 * sizeof (struct voptype_d); + else + gimple_ssa_operands (cfun)->ssa_operand_mem_size + = OP_SIZE_3 * sizeof (struct voptype_d); + + /* Go right to the maximum size if the request is too large. */ + if (size > gimple_ssa_operands (cfun)->ssa_operand_mem_size) + gimple_ssa_operands (cfun)->ssa_operand_mem_size + = OP_SIZE_3 * sizeof (struct voptype_d); + + /* We can reliably trigger the case that we need arbitrary many + operands (see PR34093), so allocate a buffer just for this request. */ + if (size > gimple_ssa_operands (cfun)->ssa_operand_mem_size) + gimple_ssa_operands (cfun)->ssa_operand_mem_size = size; + + ptr = (struct ssa_operand_memory_d *) + ggc_alloc (sizeof (struct ssa_operand_memory_d) + + gimple_ssa_operands (cfun)->ssa_operand_mem_size - 1); + ptr->next = gimple_ssa_operands (cfun)->operand_memory; + gimple_ssa_operands (cfun)->operand_memory = ptr; + gimple_ssa_operands (cfun)->operand_memory_index = 0; + } + ptr = &(gimple_ssa_operands (cfun)->operand_memory + ->mem[gimple_ssa_operands (cfun)->operand_memory_index]); + gimple_ssa_operands (cfun)->operand_memory_index += size; + return ptr; +} + + +/* Allocate a DEF operand. */ + +static inline struct def_optype_d * +alloc_def (void) +{ + struct def_optype_d *ret; + if (gimple_ssa_operands (cfun)->free_defs) + { + ret = gimple_ssa_operands (cfun)->free_defs; + gimple_ssa_operands (cfun)->free_defs + = gimple_ssa_operands (cfun)->free_defs->next; + } + else + ret = (struct def_optype_d *) + ssa_operand_alloc (sizeof (struct def_optype_d)); + return ret; +} + + +/* Allocate a USE operand. */ + +static inline struct use_optype_d * +alloc_use (void) +{ + struct use_optype_d *ret; + if (gimple_ssa_operands (cfun)->free_uses) + { + ret = gimple_ssa_operands (cfun)->free_uses; + gimple_ssa_operands (cfun)->free_uses + = gimple_ssa_operands (cfun)->free_uses->next; + } + else + ret = (struct use_optype_d *) + ssa_operand_alloc (sizeof (struct use_optype_d)); + return ret; +} + + +/* Allocate a vop with NUM elements. */ + +static inline struct voptype_d * +alloc_vop (int num) +{ + struct voptype_d *ret = NULL; + int alloc_size = 0; + + int bucket = vop_free_bucket_index (num); + if (bucket != -1) + { + /* If there is a free operand, use it. */ + if (gimple_ssa_operands (cfun)->vop_free_buckets[bucket] != NULL) + { + ret = gimple_ssa_operands (cfun)->vop_free_buckets[bucket]; + gimple_ssa_operands (cfun)->vop_free_buckets[bucket] = + gimple_ssa_operands (cfun)->vop_free_buckets[bucket]->next; + } + else + alloc_size = vop_free_bucket_size(bucket); + } + else + alloc_size = num; + + if (alloc_size > 0) + ret = (struct voptype_d *)ssa_operand_alloc ( + sizeof (struct voptype_d) + (alloc_size - 1) * sizeof (vuse_element_t)); + + VUSE_VECT_NUM_ELEM (ret->usev) = num; + return ret; +} + + +/* 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, gimple stmt) +{ + /* fold_stmt may have changed the stmt pointers. */ + if (ptr->loc.stmt != stmt) + ptr->loc.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)); +} + + +/* Adds OP to the list of defs after LAST. */ + +static inline def_optype_p +add_def_op (tree *op, def_optype_p last) +{ + def_optype_p new_def; + + new_def = alloc_def (); + DEF_OP_PTR (new_def) = op; + last->next = new_def; + new_def->next = NULL; + return new_def; +} + + +/* Adds OP to the list of uses of statement STMT after LAST. */ + +static inline use_optype_p +add_use_op (gimple stmt, tree *op, use_optype_p last) +{ + use_optype_p new_use; + + new_use = alloc_use (); + USE_OP_PTR (new_use)->use = op; + link_imm_use_stmt (USE_OP_PTR (new_use), *op, stmt); + last->next = new_use; + new_use->next = NULL; + return new_use; +} + + +/* Return a virtual op pointer with NUM elements which are all + initialized to OP and are linked into the immediate uses for STMT. + The new vop is appended after PREV. */ + +static inline voptype_p +add_vop (gimple stmt, tree op, int num, voptype_p prev) +{ + voptype_p new_vop; + int x; + + new_vop = alloc_vop (num); + for (x = 0; x < num; x++) + { + VUSE_OP_PTR (new_vop, x)->prev = NULL; + SET_VUSE_OP (new_vop, x, op); + VUSE_OP_PTR (new_vop, x)->use = &new_vop->usev.uses[x].use_var; + link_imm_use_stmt (VUSE_OP_PTR (new_vop, x), + new_vop->usev.uses[x].use_var, stmt); + } + + if (prev) + prev->next = new_vop; + new_vop->next = NULL; + return new_vop; +} + + +/* Adds OP to the list of vuses of statement STMT after LAST, and moves + LAST to the new element. */ + +static inline voptype_p +add_vuse_op (gimple stmt, tree op, int num, voptype_p last) +{ + voptype_p new_vop = add_vop (stmt, op, num, last); + VDEF_RESULT (new_vop) = NULL_TREE; + return new_vop; +} + + +/* Adds OP to the list of vdefs of statement STMT after LAST, and moves + LAST to the new element. */ + +static inline voptype_p +add_vdef_op (gimple stmt, tree op, int num, voptype_p last) +{ + voptype_p new_vop = add_vop (stmt, op, num, last); + VDEF_RESULT (new_vop) = op; + return new_vop; +} + + +/* Takes elements from build_defs and turns them into def operands of STMT. + TODO -- Make build_defs VEC of tree *. */ + +static inline void +finalize_ssa_defs (gimple stmt) +{ + unsigned new_i; + struct def_optype_d new_list; + def_optype_p old_ops, last; + unsigned int num = VEC_length (tree, build_defs); + + /* There should only be a single real definition per assignment. */ + gcc_assert ((stmt && gimple_code (stmt) != GIMPLE_ASSIGN) || num <= 1); + + new_list.next = NULL; + last = &new_list; + + old_ops = gimple_def_ops (stmt); + + new_i = 0; + + /* Check for the common case of 1 def that hasn't changed. */ + if (old_ops && old_ops->next == NULL && num == 1 + && (tree *) VEC_index (tree, build_defs, 0) == DEF_OP_PTR (old_ops)) + return; + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + old_ops->next = gimple_ssa_operands (cfun)->free_defs; + gimple_ssa_operands (cfun)->free_defs = old_ops; + } + + /* If there is anything remaining in the build_defs list, simply emit it. */ + for ( ; new_i < num; new_i++) + last = add_def_op ((tree *) VEC_index (tree, build_defs, new_i), last); + + /* Now set the stmt's operands. */ + gimple_set_def_ops (stmt, new_list.next); + +#ifdef ENABLE_CHECKING + { + def_optype_p ptr; + unsigned x = 0; + for (ptr = gimple_def_ops (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == num); + } +#endif +} + + +/* 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_uses (gimple 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 = gimple_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 = gimple_ssa_operands (cfun)->free_uses; + gimple_ssa_operands (cfun)->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++) + last = add_use_op (stmt, + (tree *) VEC_index (tree, build_uses, new_i), + last); + + /* Now set the stmt's operands. */ + gimple_set_use_ops (stmt, new_list.next); + +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_uses)); + } +#endif +} + + +/* Takes elements from BUILD_VDEFS and turns them into vdef operands of + STMT. */ + +static inline void +finalize_ssa_vdefs (gimple stmt) +{ + unsigned new_i; + struct voptype_d new_list; + voptype_p old_ops, ptr, last; + + /* Set the symbols referenced by STMT. */ + gimple_set_stored_syms (stmt, build_stores, &operands_bitmap_obstack); + + /* If aliases have not been computed, do not instantiate a virtual + operator on STMT. Initially, we only compute the SSA form on + GIMPLE registers. The virtual SSA form is only computed after + alias analysis, so virtual operators will remain unrenamed and + the verifier will complain. However, alias analysis needs to + access symbol load/store information, so we need to compute + those. */ + if (!gimple_aliases_computed_p (cfun)) + return; + + new_list.next = NULL; + last = &new_list; + + old_ops = gimple_vdef_ops (stmt); + new_i = 0; + while (old_ops && new_i < VEC_length (tree, build_vdefs)) + { + tree op = VEC_index (tree, build_vdefs, new_i); + unsigned new_uid = get_name_decl (op); + unsigned old_uid = get_name_decl (VDEF_RESULT (old_ops)); + + /* FIXME, for now each VDEF operator should have at most one + operand in their RHS. */ + gcc_assert (VDEF_NUM (old_ops) == 1); + + if (old_uid == new_uid) + { + /* If the symbols are the same, reuse the existing operand. */ + last->next = old_ops; + last = old_ops; + old_ops = old_ops->next; + last->next = NULL; + set_virtual_use_link (VDEF_OP_PTR (last, 0), stmt); + new_i++; + } + else if (old_uid < new_uid) + { + /* If old is less than new, old goes to the free list. */ + voptype_p next; + delink_imm_use (VDEF_OP_PTR (old_ops, 0)); + next = old_ops->next; + add_vop_to_freelist (old_ops); + old_ops = next; + } + else + { + /* This is a new operand. */ + last = add_vdef_op (stmt, op, 1, last); + new_i++; + } + } + + /* If there is anything remaining in BUILD_VDEFS, simply emit it. */ + for ( ; new_i < VEC_length (tree, build_vdefs); new_i++) + last = add_vdef_op (stmt, VEC_index (tree, build_vdefs, new_i), 1, last); + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (ptr = old_ops; ptr; ptr = last) + { + last = ptr->next; + delink_imm_use (VDEF_OP_PTR (ptr, 0)); + add_vop_to_freelist (ptr); + } + } + + /* Now set STMT's operands. */ + gimple_set_vdef_ops (stmt, new_list.next); + +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = gimple_vdef_ops (stmt); ptr; ptr = ptr->next) + x++; + + gcc_assert (x == VEC_length (tree, build_vdefs)); + } +#endif +} + + +/* Takes elements from BUILD_VUSES and turns them into VUSE operands of + STMT. */ + +static inline void +finalize_ssa_vuse_ops (gimple stmt) +{ + unsigned new_i, old_i; + voptype_p old_ops, last; + VEC(tree,heap) *new_ops; + + /* Set the symbols referenced by STMT. */ + gimple_set_loaded_syms (stmt, build_loads, &operands_bitmap_obstack); + + /* If aliases have not been computed, do not instantiate a virtual + operator on STMT. Initially, we only compute the SSA form on + GIMPLE registers. The virtual SSA form is only computed after + alias analysis, so virtual operators will remain unrenamed and + the verifier will complain. However, alias analysis needs to + access symbol load/store information, so we need to compute + those. */ + if (!gimple_aliases_computed_p (cfun)) + return; + + /* STMT should have at most one VUSE operator. */ + old_ops = gimple_vuse_ops (stmt); + gcc_assert (old_ops == NULL || old_ops->next == NULL); + + new_ops = NULL; + new_i = old_i = 0; + while (old_ops + && old_i < VUSE_NUM (old_ops) + && new_i < VEC_length (tree, build_vuses)) + { + tree new_op = VEC_index (tree, build_vuses, new_i); + tree old_op = VUSE_OP (old_ops, old_i); + unsigned new_uid = get_name_decl (new_op); + unsigned old_uid = get_name_decl (old_op); + + if (old_uid == new_uid) + { + /* If the symbols are the same, reuse the existing operand. */ + VEC_safe_push (tree, heap, new_ops, old_op); + new_i++; + old_i++; + } + else if (old_uid < new_uid) + { + /* If OLD_UID is less than NEW_UID, the old operand has + disappeared, skip to the next old operand. */ + old_i++; + } + else + { + /* This is a new operand. */ + VEC_safe_push (tree, heap, new_ops, new_op); + 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++) + VEC_safe_push (tree, heap, new_ops, VEC_index (tree, build_vuses, new_i)); + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (old_i = 0; old_i < VUSE_NUM (old_ops); old_i++) + delink_imm_use (VUSE_OP_PTR (old_ops, old_i)); + add_vop_to_freelist (old_ops); + gimple_set_vuse_ops (stmt, NULL); + } + + /* If there are any operands, instantiate a VUSE operator for STMT. */ + if (new_ops) + { + tree op; + unsigned i; + + last = add_vuse_op (stmt, NULL, VEC_length (tree, new_ops), NULL); + + for (i = 0; VEC_iterate (tree, new_ops, i, op); i++) + SET_USE (VUSE_OP_PTR (last, (int) i), op); + + gimple_set_vuse_ops (stmt, last); + VEC_free (tree, heap, new_ops); + } + +#ifdef ENABLE_CHECKING + { + unsigned x; + + if (gimple_vuse_ops (stmt)) + { + gcc_assert (gimple_vuse_ops (stmt)->next == NULL); + x = VUSE_NUM (gimple_vuse_ops (stmt)); + } + else + x = 0; + + gcc_assert (x == VEC_length (tree, build_vuses)); + } +#endif +} + +/* Return a new VUSE operand vector for STMT. */ + +static void +finalize_ssa_vuses (gimple stmt) +{ + unsigned num, num_vdefs; + unsigned vuse_index; + + /* Remove superfluous VUSE operands. If the statement already has a + VDEF operator for a variable 'a', then a VUSE for 'a' is not + needed because VDEFs imply a VUSE of the variable. For instance, + suppose that variable 'a' is pointed-to by p and q: + + # VUSE <a_2> + # a_3 = VDEF <a_2> + *p = *q; + + The VUSE <a_2> is superfluous because it is implied by the + VDEF operator. */ + num = VEC_length (tree, build_vuses); + num_vdefs = VEC_length (tree, build_vdefs); + + if (num > 0 && num_vdefs > 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_vdef_list) + { + VEC_ordered_remove (tree, build_vuses, vuse_index); + continue; + } + } + vuse_index++; + } + + finalize_ssa_vuse_ops (stmt); +} + + +/* Clear the in_list bits and empty the build array for VDEFs and + VUSEs. */ + +static inline void +cleanup_build_arrays (void) +{ + unsigned i; + tree t; + + for (i = 0; VEC_iterate (tree, build_vdefs, i, t); i++) + if (TREE_CODE (t) != SSA_NAME) + var_ann (t)->in_vdef_list = false; + + for (i = 0; VEC_iterate (tree, build_vuses, i, t); i++) + if (TREE_CODE (t) != SSA_NAME) + var_ann (t)->in_vuse_list = false; + + VEC_truncate (tree, build_vdefs, 0); + VEC_truncate (tree, build_vuses, 0); + VEC_truncate (tree, build_defs, 0); + VEC_truncate (tree, build_uses, 0); + bitmap_clear (build_loads); + bitmap_clear (build_stores); +} + + +/* Finalize all the build vectors, fill the new ones into INFO. */ + +static inline void +finalize_ssa_stmt_operands (gimple stmt) +{ + finalize_ssa_defs (stmt); + finalize_ssa_uses (stmt); + if (gimple_has_mem_ops (stmt)) + { + finalize_ssa_vdefs (stmt); + finalize_ssa_vuses (stmt); + } + cleanup_build_arrays (); +} + + +/* 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_vdefs) == 0); + gcc_assert (bitmap_empty_p (build_loads)); + gcc_assert (bitmap_empty_p (build_stores)); +} + + +/* 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 VAR to the set of variables that require a VDEF operator. */ + +static inline void +append_vdef (tree var) +{ + tree sym; + + if (TREE_CODE (var) != SSA_NAME) + { + tree mpt; + var_ann_t ann; + + /* If VAR belongs to a memory partition, use it instead of VAR. */ + mpt = memory_partition (var); + if (mpt) + var = mpt; + + /* Don't allow duplicate entries. */ + ann = get_var_ann (var); + if (ann->in_vdef_list) + return; + + ann->in_vdef_list = true; + sym = var; + } + else + sym = SSA_NAME_VAR (var); + + VEC_safe_push (tree, heap, build_vdefs, var); + bitmap_set_bit (build_stores, DECL_UID (sym)); +} + + +/* Add VAR to the set of variables that require a VUSE operator. */ + +static inline void +append_vuse (tree var) +{ + tree sym; + + if (TREE_CODE (var) != SSA_NAME) + { + tree mpt; + var_ann_t ann; + + /* If VAR belongs to a memory partition, use it instead of VAR. */ + mpt = memory_partition (var); + if (mpt) + var = mpt; + + /* Don't allow duplicate entries. */ + ann = get_var_ann (var); + if (ann->in_vuse_list) + return; + else if (ann->in_vdef_list) + { + /* We don't want a vuse if we already have a vdef, but we must + still put this in build_loads. */ + bitmap_set_bit (build_loads, DECL_UID (var)); + return; + } + + ann->in_vuse_list = true; + sym = var; + } + else + sym = SSA_NAME_VAR (var); + + VEC_safe_push (tree, heap, build_vuses, var); + bitmap_set_bit (build_loads, DECL_UID (sym)); +} + + +/* 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. + + XXX: We should handle the NO_ALIAS attributes here. */ + +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 == gimple_global_var (cfun)) + return true; + + /* If ref is a TARGET_MEM_REF, just return true, as we can't really + disambiguate them right now. */ + if (ref && TREE_CODE (ref) == TARGET_MEM_REF) + return true; + + /* 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. + + Another case we have to allow is accessing a variable + through an array access at offset zero. This happens from + code generated by the fortran frontend like + + char[1:1] & my_char_ref; + char my_char; + my_char_ref_1 = (char[1:1] &) &my_char; + D.874_2 = (*my_char_ref_1)[1]{lb: 1 sz: 1}; + */ + if (ref + && flag_strict_aliasing + && TREE_CODE (ref) != INDIRECT_REF + && !MTAG_P (alias) + && base + && (TREE_CODE (base) != INDIRECT_REF + || TREE_CODE (TREE_TYPE (base)) != UNION_TYPE) + && (TREE_CODE (base) != INDIRECT_REF + || TREE_CODE (ref) != ARRAY_REF + || offset != 0 + || (DECL_SIZE (alias) + && TREE_CODE (DECL_SIZE (alias)) == INTEGER_CST + && size != -1 + && (unsigned HOST_WIDE_INT)size + != TREE_INT_CST_LOW (DECL_SIZE (alias)))) + && !AGGREGATE_TYPE_P (TREE_TYPE (alias)) + && TREE_CODE (TREE_TYPE (alias)) != COMPLEX_TYPE + && !var_ann (alias)->is_heapvar + /* 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) + && !var_ann (alias)->is_heapvar + && !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 for STMT. 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. IS_CALL_SITE is true if the + affected statement is a call site. */ + +static void +add_virtual_operand (tree var, gimple stmt, int flags, + tree full_ref, HOST_WIDE_INT offset, + HOST_WIDE_INT size, bool is_call_site) +{ + bitmap aliases = NULL; + tree sym; + var_ann_t v_ann; + + sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); + v_ann = var_ann (sym); + + /* Mark the statement as having memory operands. */ + gimple_set_references_memory (stmt, true); + + /* If the variable cannot be modified and this is a VDEF 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 VDEF, 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_implicit) && unmodifiable_var_p (var)) + flags &= ~opf_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; + + if (MTAG_P (var)) + aliases = MTAG_ALIASES (var); + + if (aliases == NULL) + { + if (!gimple_aliases_computed_p (cfun) && (flags & opf_def)) + gimple_set_has_volatile_ops (stmt, true); + + /* The variable is not aliased or it is an alias tag. */ + if (flags & opf_def) + append_vdef (var); + else + append_vuse (var); + } + else + { + bitmap_iterator bi; + unsigned int i; + bool none_added = true; + + /* The variable is aliased. Add its aliases to the virtual + operands. */ + gcc_assert (!bitmap_empty_p (aliases)); + + EXECUTE_IF_SET_IN_BITMAP (aliases, 0, i, bi) + { + tree al = referenced_var (i); + + /* Call-clobbered tags may have non-call-clobbered + symbols in their alias sets. Ignore them if we are + adding VOPs for a call site. */ + if (is_call_site && !is_call_clobbered (al)) + continue; + + /* If we do not know the full reference tree or if the access is + unspecified [0, -1], we cannot prune it. Otherwise try doing + so using access_can_touch_variable. */ + if (full_ref + && !access_can_touch_variable (full_ref, al, offset, size)) + continue; + + if (flags & opf_def) + append_vdef (al); + else + append_vuse (al); + none_added = false; + } + + if (flags & opf_def) + { + /* 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 (none_added + || (TREE_CODE (var) == SYMBOL_MEMORY_TAG + && is_call_site)) + append_vdef (var); + } + else + { + /* Even if no aliases have been added, we still need to + establish def-use and use-def chains, lest + transformations think that this is not a memory + reference. For an example of this scenario, see + testsuite/g++.dg/opt/cleanup1.C. */ + if (none_added) + append_vuse (var); + } + } +} + + +/* Add *VAR_P to the appropriate operand array for statement STMT. + 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, gimple stmt, int flags) +{ + tree var, sym; + var_ann_t v_ann; + + gcc_assert (SSA_VAR_P (*var_p)); + + var = *var_p; + sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); + v_ann = var_ann (sym); + + /* Mark statements with volatile operands. */ + if (TREE_THIS_VOLATILE (sym)) + gimple_set_has_volatile_ops (stmt, true); + + if (is_gimple_reg (sym)) + { + /* The variable is a GIMPLE register. Add it to real operands. */ + if (flags & opf_def) + append_def (var_p); + else + append_use (var_p); + } + else + add_virtual_operand (var, stmt, flags, NULL_TREE, 0, -1, false); +} + +/* Subroutine of get_indirect_ref_operands. ADDR is the address + that is dereferenced, the meaning of the rest of the arguments + is the same as in get_indirect_ref_operands. */ + +static void +get_addr_dereference_operands (gimple stmt, tree *addr, int flags, + tree full_ref, HOST_WIDE_INT offset, + HOST_WIDE_INT size, bool recurse_on_base) +{ + tree ptr = *addr; + + /* Mark the statement as having memory operands. */ + gimple_set_references_memory (stmt, true); + + 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, stmt, 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 or that a propagation pass forgot to + update the alias information on the pointers. */ + if (dump_file + && TREE_CODE (ptr) == SSA_NAME + && (pi == NULL + || (pi->name_mem_tag == NULL_TREE + && !pi->pt_anything)) + && gimple_aliases_computed_p (cfun)) + { + fprintf (dump_file, + "NOTE: no flow-sensitive alias info for "); + print_generic_expr (dump_file, ptr, dump_flags); + fprintf (dump_file, " in "); + print_gimple_stmt (dump_file, stmt, 0, 0); + } + + if (TREE_CODE (ptr) == SSA_NAME) + ptr = SSA_NAME_VAR (ptr); + v_ann = var_ann (ptr); + + /* If we don't know what this pointer points to then we have + to make sure to not prune virtual operands based on offset + and size. */ + if (v_ann->symbol_mem_tag) + { + add_virtual_operand (v_ann->symbol_mem_tag, stmt, flags, + full_ref, 0, -1, false); + /* Make sure we add the SMT itself. */ + if (!(flags & opf_no_vops)) + { + if (flags & opf_def) + append_vdef (v_ann->symbol_mem_tag); + else + append_vuse (v_ann->symbol_mem_tag); + } + } + + /* Aliasing information is missing; mark statement as + volatile so we won't optimize it out too actively. */ + else if (!gimple_aliases_computed_p (cfun) + && (flags & opf_def)) + gimple_set_has_volatile_ops (stmt, true); + } + } + 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. */ + gimple_set_has_volatile_ops (stmt, 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, addr, opf_use); +} + + +/* 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 (gimple 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); + + if (TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + + get_addr_dereference_operands (stmt, pptr, flags, full_ref, offset, size, + recurse_on_base); +} + + +/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ + +static void +get_tmr_operands (gimple stmt, tree expr, int flags) +{ + tree tag; + + /* Mark the statement as having memory operands. */ + gimple_set_references_memory (stmt, true); + + /* First record the real operands. */ + get_expr_operands (stmt, &TMR_BASE (expr), opf_use); + get_expr_operands (stmt, &TMR_INDEX (expr), opf_use); + + if (TMR_SYMBOL (expr)) + gimple_add_to_addresses_taken (stmt, TMR_SYMBOL (expr)); + + tag = TMR_TAG (expr); + if (!tag) + { + /* Something weird, so ensure that we will be careful. */ + gimple_set_has_volatile_ops (stmt, true); + return; + } + if (!MTAG_P (tag)) + { + get_expr_operands (stmt, &tag, flags); + return; + } + + add_virtual_operand (tag, stmt, flags, expr, 0, -1, false); +} + + +/* Add clobbering definitions for .GLOBAL_VAR or for each of the call + clobbered variables in the function. */ + +static void +add_call_clobber_ops (gimple stmt, tree callee ATTRIBUTE_UNUSED) +{ + unsigned u; + bitmap_iterator bi; + bitmap not_read_b, not_written_b; + + gcc_assert (!(gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))); + + /* If we created .GLOBAL_VAR earlier, just use it. */ + if (gimple_global_var (cfun)) + { + tree var = gimple_global_var (cfun); + add_virtual_operand (var, stmt, opf_def, NULL, 0, -1, true); + 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 (cgraph_node (callee)) : NULL; + not_written_b = callee ? ipa_reference_get_not_written_global (cgraph_node (callee)) : NULL; + + /* Add a VDEF operand for every call clobbered variable. */ + EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun), 0, u, bi) + { + tree var = referenced_var_lookup (u); + tree real_var = var; + bool not_read; + bool not_written; + + 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. */ + + if (not_written) + { + clobber_stats.static_write_clobbers_avoided++; + if (!not_read) + add_virtual_operand (var, stmt, opf_use, NULL, 0, -1, true); + else + clobber_stats.static_read_clobbers_avoided++; + } + else + add_virtual_operand (var, stmt, opf_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 (gimple stmt, tree callee ATTRIBUTE_UNUSED) +{ + unsigned u; + bitmap_iterator bi; + bitmap not_read_b; + + /* Const functions do not reference memory. */ + if (gimple_call_flags (stmt) & ECF_CONST) + return; + + not_read_b = callee ? ipa_reference_get_not_read_global (cgraph_node (callee)) : NULL; + + /* For pure functions we compute non-escaped uses separately. */ + if (gimple_call_flags (stmt) & ECF_PURE) + EXECUTE_IF_SET_IN_BITMAP (gimple_call_used_vars (cfun), 0, u, bi) + { + tree var = referenced_var_lookup (u); + tree real_var = var; + bool not_read; + + if (unmodifiable_var_p (var)) + continue; + + not_read = not_read_b + ? bitmap_bit_p (not_read_b, DECL_UID (real_var)) + : false; + + clobber_stats.readonly_clobbers++; + + /* See if this variable is really used by this function. */ + if (!not_read) + add_virtual_operand (var, stmt, opf_use, NULL, 0, -1, true); + else + clobber_stats.static_readonly_clobbers_avoided++; + } + + /* 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 (gimple_global_var (cfun)) + { + tree var = gimple_global_var (cfun); + add_virtual_operand (var, stmt, opf_use, NULL, 0, -1, true); + return; + } + + /* Add a VUSE for each call-clobbered variable. */ + EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun), 0, u, bi) + { + tree var = referenced_var (u); + tree real_var = var; + bool not_read; + + clobber_stats.readonly_clobbers++; + + 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_virtual_operand (var, stmt, opf_use, NULL, 0, -1, true); + } +} + + +/* If STMT is a call that may clobber globals and other symbols that + escape, add them to the VDEF/VUSE lists for it. */ + +static void +maybe_add_call_clobbered_vops (gimple stmt) +{ + int call_flags = gimple_call_flags (stmt); + + /* Mark the statement as having memory operands. */ + gimple_set_references_memory (stmt, true); + + /* If aliases have been computed already, add VDEF or VUSE + operands for all the symbols that have been found to be + call-clobbered. */ + if (gimple_aliases_computed_p (cfun) && !(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 (!(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN))) + add_call_clobber_ops (stmt, gimple_call_fndecl (stmt)); + else if (!(call_flags & ECF_CONST)) + add_call_read_ops (stmt, gimple_call_fndecl (stmt)); + } +} + + +/* Scan operands in the ASM_EXPR stmt referred to in INFO. */ + +static void +get_asm_expr_operands (gimple stmt) +{ + size_t i, noutputs; + const char **oconstraints; + const char *constraint; + bool allows_mem, allows_reg, is_inout; + + noutputs = gimple_asm_noutputs (stmt); + oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *)); + + /* Gather all output operands. */ + for (i = 0; i < gimple_asm_noutputs (stmt); i++) + { + tree link = gimple_asm_output_op (stmt, i); + 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)) + gimple_add_to_addresses_taken (stmt, t); + } + + get_expr_operands (stmt, &TREE_VALUE (link), opf_def); + } + + /* Gather all input operands. */ + for (i = 0; i < gimple_asm_ninputs (stmt); i++) + { + tree link = gimple_asm_input_op (stmt, i); + 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)) + gimple_add_to_addresses_taken (stmt, t); + } + + get_expr_operands (stmt, &TREE_VALUE (link), 0); + } + + /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); */ + for (i = 0; i < gimple_asm_nclobbers (stmt); i++) + { + tree link = gimple_asm_clobber_op (stmt, i); + if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0) + { + unsigned i; + bitmap_iterator bi; + + /* Mark the statement as having memory operands. */ + gimple_set_references_memory (stmt, true); + + EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun), 0, i, bi) + { + tree var = referenced_var (i); + add_stmt_operand (&var, stmt, opf_def | opf_implicit); + } + + EXECUTE_IF_SET_IN_BITMAP (gimple_addressable_vars (cfun), 0, i, bi) + { + tree var = referenced_var (i); + add_stmt_operand (&var, stmt, opf_def | opf_implicit); + } + break; + } + } +} + + +/* 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 (gimple stmt, tree *expr_p, int flags) +{ + enum tree_code code; + enum tree_code_class codeclass; + tree expr = *expr_p; + + if (expr == NULL) + return; + + code = TREE_CODE (expr); + codeclass = 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). */ + gimple_add_to_addresses_taken (stmt, TREE_OPERAND (expr, 0)); + + /* 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 SYMBOL_MEMORY_TAG: + case NAME_MEMORY_TAG: + add_stmt_operand (expr_p, stmt, flags); + return; + + case VAR_DECL: + case PARM_DECL: + case RESULT_DECL: + add_stmt_operand (expr_p, stmt, 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, expr, 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; + + if (TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + + ref = get_ref_base_and_extent (expr, &offset, &size, &maxsize); + if (TREE_CODE (ref) == INDIRECT_REF) + { + get_indirect_ref_operands (stmt, ref, flags, expr, offset, + maxsize, false); + flags |= opf_no_vops; + } + + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + + if (code == COMPONENT_REF) + { + if (TREE_THIS_VOLATILE (TREE_OPERAND (expr, 1))) + gimple_set_has_volatile_ops (stmt, true); + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use); + } + else if (code == ARRAY_REF || code == ARRAY_RANGE_REF) + { + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_use); + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use); + get_expr_operands (stmt, &TREE_OPERAND (expr, 3), opf_use); + } + + 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_use); + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); + return; + + case COND_EXPR: + case VEC_COND_EXPR: + get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_use); + get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_use); + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use); + 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_use); + + return; + } + + case BIT_FIELD_REF: + if (TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + /* 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 CHANGE_DYNAMIC_TYPE_EXPR: + gcc_unreachable (); + + case FUNCTION_DECL: + case LABEL_DECL: + case CONST_DECL: + case CASE_LABEL_EXPR: + case FILTER_EXPR: + case EXC_PTR_EXPR: + /* Expressions that make no memory references. */ + return; + + default: + if (codeclass == tcc_unary) + goto do_unary; + if (codeclass == tcc_binary || codeclass == tcc_comparison) + goto do_binary; + if (codeclass == tcc_constant || codeclass == 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 (gimple stmt) +{ + enum gimple_code code = gimple_code (stmt); + + if (code == GIMPLE_ASM) + get_asm_expr_operands (stmt); + else + { + size_t i, start = 0; + + if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL) + { + get_expr_operands (stmt, gimple_op_ptr (stmt, 0), opf_def); + start = 1; + } + + for (i = start; i < gimple_num_ops (stmt); i++) + get_expr_operands (stmt, gimple_op_ptr (stmt, i), opf_use); + + /* Add call-clobbered operands, if needed. */ + if (code == GIMPLE_CALL) + maybe_add_call_clobbered_vops (stmt); + + /* Make sure the return value is addressable in case of NRV. */ + if (code == GIMPLE_CALL + && gimple_call_lhs (stmt) != NULL_TREE + && gimple_call_return_slot_opt_p (stmt) + && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt)))) + gimple_add_to_addresses_taken (stmt, gimple_call_lhs (stmt)); + } +} + + +/* Create an operands cache for STMT. */ + +static void +build_ssa_operands (gimple stmt) +{ + /* Initially assume that the statement has no volatile operands and + makes no memory references. */ + gimple_set_has_volatile_ops (stmt, false); + gimple_set_references_memory (stmt, false); + + /* Just clear the bitmap so we don't end up reallocating it over and over. */ + if (gimple_addresses_taken (stmt)) + bitmap_clear (gimple_addresses_taken (stmt)); + + start_ssa_stmt_operands (); + parse_ssa_operands (stmt); + operand_build_sort_virtual (build_vuses); + operand_build_sort_virtual (build_vdefs); + finalize_ssa_stmt_operands (stmt); + + /* For added safety, assume that statements with volatile operands + also reference memory. */ + if (gimple_has_volatile_ops (stmt)) + gimple_set_references_memory (stmt, true); +} + + +/* Releases the operands of STMT back to their freelists, and clears + the stmt operand lists. */ + +void +free_stmt_operands (gimple stmt) +{ + def_optype_p defs = gimple_def_ops (stmt), last_def; + use_optype_p uses = gimple_use_ops (stmt), last_use; + voptype_p vuses = gimple_vuse_ops (stmt); + voptype_p vdefs = gimple_vdef_ops (stmt), vdef, next_vdef; + unsigned i; + + if (defs) + { + for (last_def = defs; last_def->next; last_def = last_def->next) + continue; + last_def->next = gimple_ssa_operands (cfun)->free_defs; + gimple_ssa_operands (cfun)->free_defs = defs; + gimple_set_def_ops (stmt, NULL); + } + + if (uses) + { + for (last_use = uses; last_use->next; last_use = last_use->next) + delink_imm_use (USE_OP_PTR (last_use)); + delink_imm_use (USE_OP_PTR (last_use)); + last_use->next = gimple_ssa_operands (cfun)->free_uses; + gimple_ssa_operands (cfun)->free_uses = uses; + gimple_set_use_ops (stmt, NULL); + } + + if (vuses) + { + for (i = 0; i < VUSE_NUM (vuses); i++) + delink_imm_use (VUSE_OP_PTR (vuses, i)); + add_vop_to_freelist (vuses); + gimple_set_vuse_ops (stmt, NULL); + } + + if (vdefs) + { + for (vdef = vdefs; vdef; vdef = next_vdef) + { + next_vdef = vdef->next; + delink_imm_use (VDEF_OP_PTR (vdef, 0)); + add_vop_to_freelist (vdef); + } + gimple_set_vdef_ops (stmt, NULL); + } + + if (gimple_has_ops (stmt)) + gimple_set_addresses_taken (stmt, NULL); + + if (gimple_has_mem_ops (stmt)) + { + gimple_set_stored_syms (stmt, NULL, &operands_bitmap_obstack); + gimple_set_loaded_syms (stmt, NULL, &operands_bitmap_obstack); + } +} + + +/* Get the operands of statement STMT. */ + +void +update_stmt_operands (gimple stmt) +{ + /* If update_stmt_operands is called before SSA is initialized, do + nothing. */ + if (!ssa_operands_active ()) + return; + + timevar_push (TV_TREE_OPS); + + gcc_assert (gimple_modified_p (stmt)); + build_ssa_operands (stmt); + gimple_set_modified (stmt, false); + + timevar_pop (TV_TREE_OPS); +} + + +/* Copies virtual operands from SRC to DST. */ + +void +copy_virtual_operands (gimple dest, gimple src) +{ + unsigned int i, n; + voptype_p src_vuses, dest_vuses; + voptype_p src_vdefs, dest_vdefs; + struct voptype_d vuse; + struct voptype_d vdef; + + if (!gimple_has_mem_ops (src)) + return; + + gimple_set_vdef_ops (dest, NULL); + gimple_set_vuse_ops (dest, NULL); + + gimple_set_stored_syms (dest, gimple_stored_syms (src), + &operands_bitmap_obstack); + gimple_set_loaded_syms (dest, gimple_loaded_syms (src), + &operands_bitmap_obstack); + + /* Copy all the VUSE operators and corresponding operands. */ + dest_vuses = &vuse; + for (src_vuses = gimple_vuse_ops (src); + src_vuses; + src_vuses = src_vuses->next) + { + n = VUSE_NUM (src_vuses); + dest_vuses = add_vuse_op (dest, NULL_TREE, n, dest_vuses); + for (i = 0; i < n; i++) + SET_USE (VUSE_OP_PTR (dest_vuses, i), VUSE_OP (src_vuses, i)); + + if (gimple_vuse_ops (dest) == NULL) + gimple_set_vuse_ops (dest, vuse.next); + } + + /* Copy all the VDEF operators and corresponding operands. */ + dest_vdefs = &vdef; + for (src_vdefs = gimple_vdef_ops (src); + src_vdefs; + src_vdefs = src_vdefs->next) + { + n = VUSE_NUM (src_vdefs); + dest_vdefs = add_vdef_op (dest, NULL_TREE, n, dest_vdefs); + VDEF_RESULT (dest_vdefs) = VDEF_RESULT (src_vdefs); + for (i = 0; i < n; i++) + SET_USE (VUSE_OP_PTR (dest_vdefs, i), VUSE_OP (src_vdefs, i)); + + if (gimple_vdef_ops (dest) == NULL) + gimple_set_vdef_ops (dest, vdef.next); + } +} + + +/* 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. If DELINK_IMM_USES_P is specified, the immediate + uses of this stmt will be de-linked. */ + +void +create_ssa_artificial_load_stmt (gimple new_stmt, gimple old_stmt, + bool delink_imm_uses_p) +{ + tree op; + ssa_op_iter iter; + use_operand_p use_p; + unsigned i; + + gimple_set_modified (new_stmt, false); + + /* Process NEW_STMT looking for operands. */ + start_ssa_stmt_operands (); + parse_ssa_operands (new_stmt); + + for (i = 0; VEC_iterate (tree, build_vuses, i, op); i++) + if (TREE_CODE (op) != SSA_NAME) + var_ann (op)->in_vuse_list = false; + + for (i = 0; VEC_iterate (tree, build_vdefs, i, op); i++) + if (TREE_CODE (op) != SSA_NAME) + var_ann (op)->in_vdef_list = false; + + /* Remove any virtual operands that were found. */ + VEC_truncate (tree, build_vdefs, 0); + VEC_truncate (tree, build_vuses, 0); + + /* Clear the loads and stores bitmaps. */ + bitmap_clear (build_loads); + bitmap_clear (build_stores); + + /* For each VDEF on the original statement, we want to create a + VUSE of the VDEF result operand on the new statement. */ + FOR_EACH_SSA_TREE_OPERAND (op, old_stmt, iter, SSA_OP_VDEF) + append_vuse (op); + + finalize_ssa_stmt_operands (new_stmt); + + /* All uses in this fake stmt must not be in the immediate use lists. */ + if (delink_imm_uses_p) + 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 (gimple 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 = gimple_use_ops (stmt); ptr; ptr = ptr->next) + if (USE_OP_PTR (ptr)->use == exp0) + { + use0 = ptr; + break; + } + + for (ptr = gimple_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 SET. */ + +void +add_to_addressable_set (tree ref, bitmap *set) +{ + tree var; + + /* 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 (*set == NULL) + *set = BITMAP_ALLOC (&operands_bitmap_obstack); + + bitmap_set_bit (*set, DECL_UID (var)); + TREE_ADDRESSABLE (var) = 1; + } +} + + +/* Add the base address of REF to the set of addresses taken by STMT. + 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 +gimple_add_to_addresses_taken (gimple stmt, tree ref) +{ + gcc_assert (gimple_has_ops (stmt)); + add_to_addressable_set (ref, gimple_addresses_taken_ptr (stmt)); +} + + +/* 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->loc.stmt && gimple_modified_p (ptr->loc.stmt)) + { + fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->loc.stmt); + print_gimple_stmt (f, ptr->loc.stmt, 0, 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->loc.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_gimple_stmt (file, USE_STMT (use_p), 0, TDF_VOPS|TDF_MEMSYMS); + else + print_gimple_stmt (file, USE_STMT (use_p), 0, 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); +} + + +/* Create a new change buffer for the statement pointed by STMT_P and + push the buffer into SCB_STACK. Each change buffer + records state information needed to determine what changed in the + statement. Mainly, this keeps track of symbols that may need to be + put into SSA form, SSA name replacements and other information + needed to keep the SSA form up to date. */ + +void +push_stmt_changes (gimple *stmt_p) +{ + gimple stmt; + scb_t buf; + + stmt = *stmt_p; + + /* It makes no sense to keep track of PHI nodes. */ + if (gimple_code (stmt) == GIMPLE_PHI) + return; + + buf = XNEW (struct scb_d); + memset (buf, 0, sizeof *buf); + + buf->stmt_p = stmt_p; + + if (gimple_references_memory_p (stmt)) + { + tree op; + ssa_op_iter i; + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VUSE) + { + tree sym = TREE_CODE (op) == SSA_NAME ? SSA_NAME_VAR (op) : op; + if (buf->loads == NULL) + buf->loads = BITMAP_ALLOC (NULL); + bitmap_set_bit (buf->loads, DECL_UID (sym)); + } + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VDEF) + { + tree sym = TREE_CODE (op) == SSA_NAME ? SSA_NAME_VAR (op) : op; + if (buf->stores == NULL) + buf->stores = BITMAP_ALLOC (NULL); + bitmap_set_bit (buf->stores, DECL_UID (sym)); + } + } + + VEC_safe_push (scb_t, heap, scb_stack, buf); +} + + +/* Given two sets S1 and S2, mark the symbols that differ in S1 and S2 + for renaming. The set to mark for renaming is (S1 & ~S2) | (S2 & ~S1). */ + +static void +mark_difference_for_renaming (bitmap s1, bitmap s2) +{ + if (s1 == NULL && s2 == NULL) + return; + + if (s1 && s2 == NULL) + mark_set_for_renaming (s1); + else if (s1 == NULL && s2) + mark_set_for_renaming (s2); + else if (!bitmap_equal_p (s1, s2)) + { + bitmap t1 = BITMAP_ALLOC (NULL); + bitmap_xor (t1, s1, s2); + mark_set_for_renaming (t1); + BITMAP_FREE (t1); + } +} + + +/* Pop the top SCB from SCB_STACK and act on the differences between + what was recorded by push_stmt_changes and the current state of + the statement. */ + +void +pop_stmt_changes (gimple *stmt_p) +{ + tree op; + gimple stmt; + ssa_op_iter iter; + bitmap loads, stores; + scb_t buf; + + stmt = *stmt_p; + + /* It makes no sense to keep track of PHI nodes. */ + if (gimple_code (stmt) == GIMPLE_PHI) + return; + + buf = VEC_pop (scb_t, scb_stack); + gcc_assert (stmt_p == buf->stmt_p); + + /* Force an operand re-scan on the statement and mark any newly + exposed variables. */ + update_stmt (stmt); + + /* Determine whether any memory symbols need to be renamed. If the + sets of loads and stores are different after the statement is + modified, then the affected symbols need to be renamed. + + Note that it may be possible for the statement to not reference + memory anymore, but we still need to act on the differences in + the sets of symbols. */ + loads = stores = NULL; + if (gimple_references_memory_p (stmt)) + { + tree op; + ssa_op_iter i; + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VUSE) + { + tree sym = TREE_CODE (op) == SSA_NAME ? SSA_NAME_VAR (op) : op; + if (loads == NULL) + loads = BITMAP_ALLOC (NULL); + bitmap_set_bit (loads, DECL_UID (sym)); + } + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VDEF) + { + tree sym = TREE_CODE (op) == SSA_NAME ? SSA_NAME_VAR (op) : op; + if (stores == NULL) + stores = BITMAP_ALLOC (NULL); + bitmap_set_bit (stores, DECL_UID (sym)); + } + } + + /* If LOADS is different from BUF->LOADS, the affected + symbols need to be marked for renaming. */ + mark_difference_for_renaming (loads, buf->loads); + + /* Similarly for STORES and BUF->STORES. */ + mark_difference_for_renaming (stores, buf->stores); + + /* Mark all the naked GIMPLE register operands for renaming. */ + FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF|SSA_OP_USE) + if (DECL_P (op)) + mark_sym_for_renaming (op); + + /* FIXME, need to add more finalizers here. Cleanup EH info, + recompute invariants for address expressions, add + SSA replacement mappings, etc. For instance, given + testsuite/gcc.c-torture/compile/pr16808.c, we fold a statement of + the form: + + # SMT.4_20 = VDEF <SMT.4_16> + D.1576_11 = 1.0e+0; + + So, the VDEF will disappear, but instead of marking SMT.4 for + renaming it would be far more efficient to establish a + replacement mapping that would replace every reference of + SMT.4_20 with SMT.4_16. */ + + /* Free memory used by the buffer. */ + BITMAP_FREE (buf->loads); + BITMAP_FREE (buf->stores); + BITMAP_FREE (loads); + BITMAP_FREE (stores); + buf->stmt_p = NULL; + free (buf); +} + + +/* Discard the topmost change buffer from SCB_STACK. This is useful + when the caller realized that it did not actually modified the + statement. It avoids the expensive operand re-scan. */ + +void +discard_stmt_changes (gimple *stmt_p) +{ + scb_t buf; + gimple stmt; + + /* It makes no sense to keep track of PHI nodes. */ + stmt = *stmt_p; + if (gimple_code (stmt) == GIMPLE_PHI) + return; + + buf = VEC_pop (scb_t, scb_stack); + gcc_assert (stmt_p == buf->stmt_p); + + /* Free memory used by the buffer. */ + BITMAP_FREE (buf->loads); + BITMAP_FREE (buf->stores); + buf->stmt_p = NULL; + free (buf); +} |