X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Ftree-ssa-operands.c;h=23e493a2b04fac3334d29ce5926acc7eb58108a9;hb=7e4767132361a420a3b82a1a093215c0d7121c85;hp=de5150e60099db5347374caae51588e5d4ab50d5;hpb=ac8fc89a6274b3cbfd4feebeb89e9e35c2226512;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c index de5150e6009..23e493a2b04 100644 --- a/gcc/tree-ssa-operands.c +++ b/gcc/tree-ssa-operands.c @@ -1,5 +1,5 @@ /* SSA operands management for trees. - Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc. + Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc. This file is part of GCC. @@ -15,8 +15,8 @@ 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, 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ +the Free Software Foundation, 51 Franklin Street, Fifth Floor, +Boston, MA 02110-1301, USA. */ #include "config.h" #include "system.h" @@ -26,14 +26,14 @@ Boston, MA 02111-1307, USA. */ #include "flags.h" #include "function.h" #include "diagnostic.h" -#include "errors.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 @@ -50,24 +50,21 @@ Boston, MA 02111-1307, USA. */ The routines in this file are concerned with creating this operand cache from a stmt tree. - get_stmt_operands() in the primary entry point. - 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. + 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 5 operand vectors which have been built up. + 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 its a perfect + 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 @@ -76,22 +73,46 @@ Boston, MA 02111-1307, USA. */ 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'. + it contains 'a_5' rather than 'a'. */ + + +/* 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 get_stmt_operands and helpers. */ +/* Flags to describe operand properties in helpers. */ /* By default, operands are loaded. */ -#define opf_none 0 +#define opf_use 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) + 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 @@ -99,197 +120,265 @@ Boston, MA 02111-1307, USA. */ 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) +#define opf_no_vops (1 << 1) + +/* Operand is an implicit reference. This is used to distinguish + explicit assignments in the form of GIMPLE_MODIFY_STMT from + clobbering sites like function calls or ASM_EXPRs. */ +#define opf_implicit (1 << 2) /* Array for building all the def operands. */ -static GTY (()) varray_type build_defs; +static VEC(tree,heap) *build_defs; /* Array for building all the use operands. */ -static GTY (()) varray_type build_uses; +static VEC(tree,heap) *build_uses; -/* Array for building all the v_may_def operands. */ -static GTY (()) varray_type build_v_may_defs; +/* Set for building all the VDEF operands. */ +static VEC(tree,heap) *build_vdefs; -/* Array for building all the vuse operands. */ -static GTY (()) varray_type build_vuses; +/* Set for building all the VUSE operands. */ +static VEC(tree,heap) *build_vuses; -/* Array for building all the v_must_def operands. */ -static GTY (()) varray_type build_v_must_defs; +/* 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; -/* True if the operands for call clobbered vars are cached and valid. */ -bool ssa_call_clobbered_cache_valid; -bool ssa_ro_call_cache_valid; +/* Set for building all the stored symbols. */ +static bitmap build_stores; -/* These arrays are the cached operand vectors for call clobbered calls. */ -static GTY (()) varray_type clobbered_v_may_defs; -static GTY (()) varray_type clobbered_vuses; -static GTY (()) varray_type ro_call_vuses; -static bool clobbered_aliased_loads; -static bool clobbered_aliased_stores; -static bool ro_call_aliased_loads; +static void get_expr_operands (tree, tree *, int); -def_operand_p NULL_DEF_OPERAND_P = { NULL }; -use_operand_p NULL_USE_OPERAND_P = { NULL }; +/* Number of functions with initialized ssa_operands. */ +static int n_initialized = 0; -static void note_addressable (tree, stmt_ann_t); -static void get_expr_operands (tree, tree *, int); -static void get_asm_expr_operands (tree); -static void get_indirect_ref_operands (tree, tree, int); -static void get_call_expr_operands (tree, tree); -static inline void append_def (tree *); -static inline void append_use (tree *); -static void append_v_may_def (tree); -static void append_v_must_def (tree); -static void add_call_clobber_ops (tree); -static void add_call_read_ops (tree); -static void add_stmt_operand (tree *, stmt_ann_t, int); +/* 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: -/* Return a vector of contiguous memory for NUM def operands. */ + 1- Call push_stmt_changes (&stmt) to record the current state of + STMT before any modifications are made. -static inline def_optype -allocate_def_optype (unsigned num) -{ - def_optype def_ops; - unsigned size; - size = sizeof (struct def_optype_d) + sizeof (tree *) * (num - 1); - def_ops = ggc_alloc (size); - def_ops->num_defs = num; - return def_ops; -} + 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. -/* Return a vector of contiguous memory for NUM use operands. */ + 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. */ -static inline use_optype -allocate_use_optype (unsigned num) +struct scb_d { - use_optype use_ops; - unsigned size; - size = sizeof (struct use_optype_d) + sizeof (tree *) * (num - 1); - use_ops = ggc_alloc (size); - use_ops->num_uses = num; - return use_ops; -} - + /* Pointer to the statement being modified. */ + tree *stmt_p; -/* Return a vector of contiguous memory for NUM v_may_def operands. */ + /* If the statement references memory these are the sets of symbols + loaded and stored by the statement. */ + bitmap loads; + bitmap stores; +}; -static inline v_may_def_optype -allocate_v_may_def_optype (unsigned num) -{ - v_may_def_optype v_may_def_ops; - unsigned size; - size = sizeof (struct v_may_def_optype_d) - + sizeof (v_def_use_operand_type_t) * (num - 1); - v_may_def_ops = ggc_alloc (size); - v_may_def_ops->num_v_may_defs = num; - return v_may_def_ops; -} +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 a vector of contiguous memory for NUM v_use operands. */ +/* Return the DECL_UID of the base variable of T. */ -static inline vuse_optype -allocate_vuse_optype (unsigned num) +static inline unsigned +get_name_decl (tree t) { - vuse_optype vuse_ops; - unsigned size; - size = sizeof (struct vuse_optype_d) + sizeof (tree) * (num - 1); - vuse_ops = ggc_alloc (size); - vuse_ops->num_vuses = num; - return vuse_ops; + if (TREE_CODE (t) != SSA_NAME) + return DECL_UID (t); + else + return DECL_UID (SSA_NAME_VAR (t)); } -/* Return a vector of contiguous memory for NUM v_must_def operands. */ +/* Comparison function for qsort used in operand_build_sort_virtual. */ -static inline v_must_def_optype -allocate_v_must_def_optype (unsigned num) +static int +operand_build_cmp (const void *p, const void *q) { - v_must_def_optype v_must_def_ops; - unsigned size; - size = sizeof (struct v_must_def_optype_d) + sizeof (v_def_use_operand_type_t) * (num - 1); - v_must_def_ops = ggc_alloc (size); - v_must_def_ops->num_v_must_defs = num; - return v_must_def_ops; + 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); } -/* Free memory for USES. */ +/* Sort the virtual operands in LIST from lowest DECL_UID to highest. */ static inline void -free_uses (use_optype *uses) +operand_build_sort_virtual (VEC(tree,heap) *list) { - if (*uses) + int num = VEC_length (tree, list); + + if (num < 2) + return; + + if (num == 2) { - ggc_free (*uses); - *uses = NULL; + 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); } -/* Free memory for DEFS. */ +/* Return true if the SSA operands cache is active. */ -static inline void -free_defs (def_optype *defs) +bool +ssa_operands_active (void) { - if (*defs) - { - ggc_free (*defs); - *defs = NULL; - } + return cfun->gimple_df && gimple_ssa_operands (cfun)->ops_active; } -/* Free memory for VUSES. */ +/* 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. */ -static inline void -free_vuses (vuse_optype *vuses) + +/* Return the number of operands used in bucket BUCKET. */ + +static inline int +vop_free_bucket_size (int bucket) { - if (*vuses) - { - ggc_free (*vuses); - *vuses = NULL; - } +#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); + + /* Sizes 1 through 16 use buckets 0-15. */ + if (num <= 16) + return num - 1; + /* Buckets 16 - 45 represent 17 through 256 in 8 unit chunks. */ + if (num < 256) + return 14 + (num - 1) / 8; + return -1; } -/* Free memory for V_MAY_DEFS. */ +/* Initialize the VOP free buckets. */ static inline void -free_v_may_defs (v_may_def_optype *v_may_defs) +init_vop_buckets (void) { - if (*v_may_defs) - { - ggc_free (*v_may_defs); - *v_may_defs = NULL; - } + int x; + + for (x = 0; x < NUM_VOP_FREE_BUCKETS; x++) + gimple_ssa_operands (cfun)->vop_free_buckets[x] = NULL; } -/* Free memory for V_MUST_DEFS. */ +/* Add PTR to the appropriate VOP bucket. */ static inline void -free_v_must_defs (v_must_def_optype *v_must_defs) +add_vop_to_freelist (voptype_p ptr) { - if (*v_must_defs) - { - ggc_free (*v_must_defs); - *v_must_defs = NULL; - } + 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) { - VARRAY_TREE_PTR_INIT (build_defs, 5, "build defs"); - VARRAY_TREE_PTR_INIT (build_uses, 10, "build uses"); - VARRAY_TREE_INIT (build_v_may_defs, 10, "build v_may_defs"); - VARRAY_TREE_INIT (build_vuses, 10, "build vuses"); - VARRAY_TREE_INIT (build_v_must_defs, 10, "build v_must_defs"); + 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; } @@ -298,736 +387,1645 @@ init_ssa_operands (void) void fini_ssa_operands (void) { - ggc_free (build_defs); - ggc_free (build_uses); - ggc_free (build_v_may_defs); - ggc_free (build_vuses); - ggc_free (build_v_must_defs); - build_defs = NULL; - build_uses = NULL; - build_v_may_defs = NULL; - build_vuses = NULL; - build_v_must_defs = NULL; - if (clobbered_v_may_defs) + struct ssa_operand_memory_d *ptr; + unsigned ix; + tree mpt; + + if (!--n_initialized) { - ggc_free (clobbered_v_may_defs); - ggc_free (clobbered_vuses); - clobbered_v_may_defs = NULL; - clobbered_vuses = NULL; + 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; } - if (ro_call_vuses) + + gimple_ssa_operands (cfun)->free_defs = NULL; + gimple_ssa_operands (cfun)->free_uses = NULL; + + while ((ptr = gimple_ssa_operands (cfun)->operand_memory) != NULL) { - ggc_free (ro_call_vuses); - ro_call_vuses = NULL; + gimple_ssa_operands (cfun)->operand_memory + = gimple_ssa_operands (cfun)->operand_memory->next; + ggc_free (ptr); } -} - -/* All the finalize_ssa_* routines do the work required to turn the build_ - VARRAY into an operand_vector of the appropriate type. The original vector, - if any, is passed in for comparison and virtual SSA_NAME reuse. If the - old vector is reused, the pointer passed in is set to NULL so that - the memory is not freed when the old operands are freed. */ + for (ix = 0; + VEC_iterate (tree, gimple_ssa_operands (cfun)->mpt_table, ix, mpt); + ix++) + { + if (mpt) + BITMAP_FREE (MPT_SYMBOLS (mpt)); + } -/* Return a new def operand vector for STMT, comparing to OLD_OPS_P. */ + VEC_free (tree, heap, gimple_ssa_operands (cfun)->mpt_table); -static def_optype -finalize_ssa_defs (def_optype *old_ops_p, tree stmt ATTRIBUTE_UNUSED) -{ - unsigned num, x; - def_optype def_ops, old_ops; - bool build_diff; + gimple_ssa_operands (cfun)->ops_active = false; - num = VARRAY_ACTIVE_SIZE (build_defs); - if (num == 0) - return NULL; + 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); + } +} - /* There should only be a single real definition per assignment. */ - gcc_assert (TREE_CODE (stmt) != MODIFY_EXPR || num <= 1); - old_ops = *old_ops_p; +/* Return memory for operands of SIZE chunks. */ + +static inline void * +ssa_operand_alloc (unsigned size) +{ + char *ptr; - /* Compare old vector and new array. */ - build_diff = true; - if (old_ops && old_ops->num_defs == num) + if (gimple_ssa_operands (cfun)->operand_memory_index + size + >= gimple_ssa_operands (cfun)->ssa_operand_mem_size) { - build_diff = false; - for (x = 0; x < num; x++) - if (old_ops->defs[x].def != VARRAY_TREE_PTR (build_defs, x)) - { - build_diff = true; - break; - } - } + struct ssa_operand_memory_d *ptr; - if (!build_diff) - { - def_ops = old_ops; - *old_ops_p = NULL; - } - else - { - def_ops = allocate_def_optype (num); - for (x = 0; x < num ; x++) - def_ops->defs[x].def = VARRAY_TREE_PTR (build_defs, x); + 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); + + /* Fail if there is not enough space. If there are this many operands + required, first make sure there isn't a different problem causing this + many operands. If the decision is that this is OK, then we can + specially allocate a buffer just for this request. */ + gcc_assert (size <= gimple_ssa_operands (cfun)->ssa_operand_mem_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; } - - VARRAY_POP_ALL (build_defs); - - return def_ops; + 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; } -/* Return a new use operand vector for STMT, comparing to OLD_OPS_P. */ +/* Allocate a DEF operand. */ -static use_optype -finalize_ssa_uses (use_optype *old_ops_p, tree stmt ATTRIBUTE_UNUSED) +static inline struct def_optype_d * +alloc_def (void) { - unsigned num, x; - use_optype use_ops, old_ops; - bool build_diff; - - num = VARRAY_ACTIVE_SIZE (build_uses); - if (num == 0) - return NULL; - -#ifdef ENABLE_CHECKING - { - unsigned x; - /* 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 get_stmt_operands does not pass a pointer to a - statement). */ - for (x = 0; x < num; x++) - gcc_assert (*(VARRAY_TREE_PTR (build_uses, x)) != stmt); - } -#endif - old_ops = *old_ops_p; - - /* Check if the old vector and the new array are the same. */ - build_diff = true; - if (old_ops && old_ops->num_uses == num) + struct def_optype_d *ret; + if (gimple_ssa_operands (cfun)->free_defs) { - build_diff = false; - for (x = 0; x < num; x++) - if (old_ops->uses[x].use != VARRAY_TREE_PTR (build_uses, x)) - { - build_diff = true; - break; - } + 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; +} + - if (!build_diff) +/* 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) { - use_ops = old_ops; - *old_ops_p = NULL; + ret = gimple_ssa_operands (cfun)->free_uses; + gimple_ssa_operands (cfun)->free_uses + = gimple_ssa_operands (cfun)->free_uses->next; } else - { - use_ops = allocate_use_optype (num); - for (x = 0; x < num ; x++) - use_ops->uses[x].use = VARRAY_TREE_PTR (build_uses, x); - } - VARRAY_POP_ALL (build_uses); - - return use_ops; + ret = (struct use_optype_d *) + ssa_operand_alloc (sizeof (struct use_optype_d)); + return ret; } -/* Return a new v_may_def operand vector for STMT, comparing to OLD_OPS_P. */ +/* Allocate a vop with NUM elements. */ -static v_may_def_optype -finalize_ssa_v_may_defs (v_may_def_optype *old_ops_p) +static inline struct voptype_d * +alloc_vop (int num) { - unsigned num, x, i, old_num; - v_may_def_optype v_may_def_ops, old_ops; - tree result, var; - bool build_diff; - - num = VARRAY_ACTIVE_SIZE (build_v_may_defs); - if (num == 0) - return NULL; + struct voptype_d *ret = NULL; + int alloc_size = 0; - old_ops = *old_ops_p; - - /* Check if the old vector and the new array are the same. */ - build_diff = true; - if (old_ops && old_ops->num_v_may_defs == num) + int bucket = vop_free_bucket_index (num); + if (bucket != -1) { - old_num = num; - build_diff = false; - for (x = 0; x < num; x++) - { - var = old_ops->v_may_defs[x].def; - if (TREE_CODE (var) == SSA_NAME) - var = SSA_NAME_VAR (var); - if (var != VARRAY_TREE (build_v_may_defs, x)) - { - build_diff = true; - break; - } + /* 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 - old_num = (old_ops ? old_ops->num_v_may_defs : 0); - - if (!build_diff) - { - v_may_def_ops = old_ops; - *old_ops_p = NULL; - } - else - { - v_may_def_ops = allocate_v_may_def_optype (num); - for (x = 0; x < num; x++) - { - var = VARRAY_TREE (build_v_may_defs, x); - /* Look for VAR in the old operands vector. */ - for (i = 0; i < old_num; i++) - { - result = old_ops->v_may_defs[i].def; - if (TREE_CODE (result) == SSA_NAME) - result = SSA_NAME_VAR (result); - if (result == var) - { - v_may_def_ops->v_may_defs[x] = old_ops->v_may_defs[i]; - break; - } - } - if (i == old_num) - { - v_may_def_ops->v_may_defs[x].def = var; - v_may_def_ops->v_may_defs[x].use = var; - } - } - } + alloc_size = num; - /* Empty the V_MAY_DEF build vector after VUSES have been processed. */ + if (alloc_size > 0) + ret = (struct voptype_d *)ssa_operand_alloc ( + sizeof (struct voptype_d) + (alloc_size - 1) * sizeof (vuse_element_t)); - return v_may_def_ops; + VUSE_VECT_NUM_ELEM (ret->usev) = num; + return ret; } -/* Clear the in_list bits and empty the build array for v_may_defs. */ +/* 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 -cleanup_v_may_defs (void) +set_virtual_use_link (use_operand_p ptr, tree stmt) { - unsigned x, num; - num = VARRAY_ACTIVE_SIZE (build_v_may_defs); + /* fold_stmt may have changed the stmt pointers. */ + if (ptr->stmt != stmt) + ptr->stmt = stmt; - for (x = 0; x < num; x++) - { - tree t = VARRAY_TREE (build_v_may_defs, x); - var_ann_t ann = var_ann (t); - ann->in_v_may_def_list = 0; - } - VARRAY_POP_ALL (build_v_may_defs); + /* If this use isn't in a list, add it to the correct list. */ + if (!ptr->prev) + link_imm_use (ptr, *(ptr->use)); } -/* Return a new vuse operand vector, comparing to OLD_OPS_P. */ -static vuse_optype -finalize_ssa_vuses (vuse_optype *old_ops_p) +/* Adds OP to the list of defs after LAST. */ + +static inline def_optype_p +add_def_op (tree *op, def_optype_p last) { - unsigned num, x, i, num_v_may_defs, old_num; - vuse_optype vuse_ops, old_ops; - bool build_diff; + def_optype_p new; - num = VARRAY_ACTIVE_SIZE (build_vuses); - if (num == 0) - { - cleanup_v_may_defs (); - return NULL; - } + new = alloc_def (); + DEF_OP_PTR (new) = op; + last->next = new; + new->next = NULL; + return new; +} - /* 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_3 = V_MAY_DEF - a = a + 1; +/* Adds OP to the list of uses of statement STMT after LAST. */ - The VUSE is superfluous because it is implied by the V_MAY_DEF - operation. */ +static inline use_optype_p +add_use_op (tree stmt, tree *op, use_optype_p last) +{ + use_optype_p new; + + new = alloc_use (); + USE_OP_PTR (new)->use = op; + link_imm_use_stmt (USE_OP_PTR (new), *op, stmt); + last->next = new; + new->next = NULL; + return new; +} - num_v_may_defs = VARRAY_ACTIVE_SIZE (build_v_may_defs); - if (num_v_may_defs > 0) - { - size_t i; - tree vuse; - for (i = 0; i < VARRAY_ACTIVE_SIZE (build_vuses); i++) - { - vuse = VARRAY_TREE (build_vuses, i); - 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) - { - /* If we found a useless VUSE operand, remove it from the - operand array by replacing it with the last active element - in the operand array (unless the useless VUSE was the - last operand, in which case we simply remove it. */ - if (i != VARRAY_ACTIVE_SIZE (build_vuses) - 1) - { - VARRAY_TREE (build_vuses, i) - = VARRAY_TREE (build_vuses, - VARRAY_ACTIVE_SIZE (build_vuses) - 1); - } - VARRAY_POP (build_vuses); - - /* We want to rescan the element at this index, unless - this was the last element, in which case the loop - terminates. */ - i--; - } - } - } - } - else - /* Clear out the in_list bits. */ - for (x = 0; x < num; x++) - { - tree t = VARRAY_TREE (build_vuses, x); - if (TREE_CODE (t) != SSA_NAME) - { - var_ann_t ann = var_ann (t); - ann->in_vuse_list = 0; - } - } +/* 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 (tree stmt, tree op, int num, voptype_p prev) +{ + voptype_p new; + int x; - num = VARRAY_ACTIVE_SIZE (build_vuses); - /* We could have reduced the size to zero now, however. */ - if (num == 0) + new = alloc_vop (num); + for (x = 0; x < num; x++) { - cleanup_v_may_defs (); - return NULL; + VUSE_OP_PTR (new, x)->prev = NULL; + SET_VUSE_OP (new, x, op); + VUSE_OP_PTR (new, x)->use = &new->usev.uses[x].use_var; + link_imm_use_stmt (VUSE_OP_PTR (new, x), new->usev.uses[x].use_var, stmt); } - old_ops = *old_ops_p; + if (prev) + prev->next = new; + new->next = NULL; + return new; +} - /* Determine whether vuses is the same as the old vector. */ - build_diff = true; - if (old_ops && old_ops->num_vuses == num) - { - old_num = num; - build_diff = false; - for (x = 0; x < num ; x++) - { - tree v; - v = old_ops->vuses[x]; - if (TREE_CODE (v) == SSA_NAME) - v = SSA_NAME_VAR (v); - if (v != VARRAY_TREE (build_vuses, x)) - { - build_diff = true; - break; - } - } - } - else - old_num = (old_ops ? old_ops->num_vuses : 0); - if (!build_diff) - { - vuse_ops = old_ops; - *old_ops_p = NULL; - } - else - { - vuse_ops = allocate_vuse_optype (num); - for (x = 0; x < num; x++) - { - tree result, var = VARRAY_TREE (build_vuses, x); - /* Look for VAR in the old vector, and use that SSA_NAME. */ - for (i = 0; i < old_num; i++) - { - result = old_ops->vuses[i]; - if (TREE_CODE (result) == SSA_NAME) - result = SSA_NAME_VAR (result); - if (result == var) - { - vuse_ops->vuses[x] = old_ops->vuses[i]; - break; - } - } - if (i == old_num) - vuse_ops->vuses[x] = var; - } - } +/* 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 (tree stmt, tree op, int num, voptype_p last) +{ + voptype_p new = add_vop (stmt, op, num, last); + VDEF_RESULT (new) = NULL_TREE; + return new; +} - /* The v_may_def build vector wasn't freed because we needed it here. - Free it now with the vuses build vector. */ - VARRAY_POP_ALL (build_vuses); - cleanup_v_may_defs (); - return vuse_ops; +/* 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 (tree stmt, tree op, int num, voptype_p last) +{ + voptype_p new = add_vop (stmt, op, num, last); + VDEF_RESULT (new) = op; + return new; } + -/* Return a new v_must_def operand vector for STMT, comparing to OLD_OPS_P. */ +/* Reallocate the virtual operand PTR so that it has NUM_ELEM use slots. ROOT + is the head of the operand list it belongs to. */ -static v_must_def_optype -finalize_ssa_v_must_defs (v_must_def_optype *old_ops_p, - tree stmt ATTRIBUTE_UNUSED) +static inline struct voptype_d * +realloc_vop (struct voptype_d *ptr, int num_elem, struct voptype_d **root) { - unsigned num, x, i, old_num = 0; - v_must_def_optype v_must_def_ops, old_ops; - bool build_diff; + int x, lim; + tree stmt, val; + struct voptype_d *ret, *tmp; - num = VARRAY_ACTIVE_SIZE (build_v_must_defs); - if (num == 0) - return NULL; + if (VUSE_VECT_NUM_ELEM (ptr->usev) == num_elem) + return ptr; - /* There should only be a single V_MUST_DEF per assignment. */ - gcc_assert (TREE_CODE (stmt) != MODIFY_EXPR || num <= 1); + val = VUSE_OP (ptr, 0); + if (TREE_CODE (val) == SSA_NAME) + val = SSA_NAME_VAR (val); - old_ops = *old_ops_p; + stmt = USE_STMT (VUSE_OP_PTR (ptr, 0)); - /* Check if the old vector and the new array are the same. */ - build_diff = true; - if (old_ops && old_ops->num_v_must_defs == num) + /* Delink all the existing uses. */ + for (x = 0; x < VUSE_VECT_NUM_ELEM (ptr->usev); x++) { - old_num = num; - build_diff = false; - for (x = 0; x < num; x++) - { - tree var = old_ops->v_must_defs[x].def; - if (TREE_CODE (var) == SSA_NAME) - var = SSA_NAME_VAR (var); - if (var != VARRAY_TREE (build_v_must_defs, x)) - { - build_diff = true; - break; - } - } + use_operand_p use_p = VUSE_OP_PTR (ptr, x); + delink_imm_use (use_p); } - else - old_num = (old_ops ? old_ops->num_v_must_defs : 0); - if (!build_diff) + /* If we want less space, simply use this one, and shrink the size. */ + if (VUSE_VECT_NUM_ELEM (ptr->usev) > num_elem) { - v_must_def_ops = old_ops; - *old_ops_p = NULL; + VUSE_VECT_NUM_ELEM (ptr->usev) = num_elem; + return ptr; } - else + + /* It is growing. Allocate a new one and replace the old one. */ + ret = add_vuse_op (stmt, val, num_elem, ptr); + + /* Clear PTR and add its memory to the free list. */ + lim = VUSE_VECT_NUM_ELEM (ptr->usev); + memset (ptr, 0, + sizeof (struct voptype_d) + sizeof (vuse_element_t) * (lim- 1)); + add_vop_to_freelist (ptr); + + /* Now simply remove the old one. */ + if (*root == ptr) { - v_must_def_ops = allocate_v_must_def_optype (num); - for (x = 0; x < num ; x++) - { - tree result, var = VARRAY_TREE (build_v_must_defs, x); - /* Look for VAR in the original vector. */ - for (i = 0; i < old_num; i++) - { - result = old_ops->v_must_defs[i].def; - if (TREE_CODE (result) == SSA_NAME) - result = SSA_NAME_VAR (result); - if (result == var) - { - v_must_def_ops->v_must_defs[x].def = old_ops->v_must_defs[i].def; - v_must_def_ops->v_must_defs[x].use = old_ops->v_must_defs[i].use; - break; - } - } - if (i == old_num) - { - v_must_def_ops->v_must_defs[x].def = var; - v_must_def_ops->v_must_defs[x].use = var; - } - } + *root = ret; + return ret; } - VARRAY_POP_ALL (build_v_must_defs); + else + for (tmp = *root; + tmp != NULL && tmp->next != ptr; + tmp = tmp->next) + { + tmp->next = ret; + return ret; + } - return v_must_def_ops; + /* The pointer passed in isn't in STMT's VDEF lists. */ + gcc_unreachable (); } + +/* Reallocate the PTR vdef so that it has NUM_ELEM use slots. */ -/* Finalize all the build vectors, fill the new ones into INFO. */ - -static inline void -finalize_ssa_stmt_operands (tree stmt, stmt_operands_p old_ops, - stmt_operands_p new_ops) +struct voptype_d * +realloc_vdef (struct voptype_d *ptr, int num_elem) { - new_ops->def_ops = finalize_ssa_defs (&(old_ops->def_ops), stmt); - new_ops->use_ops = finalize_ssa_uses (&(old_ops->use_ops), stmt); - new_ops->v_must_def_ops - = finalize_ssa_v_must_defs (&(old_ops->v_must_def_ops), stmt); - new_ops->v_may_def_ops = finalize_ssa_v_may_defs (&(old_ops->v_may_def_ops)); - new_ops->vuse_ops = finalize_ssa_vuses (&(old_ops->vuse_ops)); + tree val, stmt; + struct voptype_d *ret; + + val = VDEF_RESULT (ptr); + stmt = USE_STMT (VDEF_OP_PTR (ptr, 0)); + ret = realloc_vop (ptr, num_elem, &(VDEF_OPS (stmt))); + VDEF_RESULT (ret) = val; + return ret; } + +/* Reallocate the PTR vuse so that it has NUM_ELEM use slots. */ -/* Start the process of building up operands vectors in INFO. */ - -static inline void -start_ssa_stmt_operands (void) +struct voptype_d * +realloc_vuse (struct voptype_d *ptr, int num_elem) { - gcc_assert (VARRAY_ACTIVE_SIZE (build_defs) == 0); - gcc_assert (VARRAY_ACTIVE_SIZE (build_uses) == 0); - gcc_assert (VARRAY_ACTIVE_SIZE (build_vuses) == 0); - gcc_assert (VARRAY_ACTIVE_SIZE (build_v_may_defs) == 0); - gcc_assert (VARRAY_ACTIVE_SIZE (build_v_must_defs) == 0); + tree stmt; + struct voptype_d *ret; + + stmt = USE_STMT (VUSE_OP_PTR (ptr, 0)); + ret = realloc_vop (ptr, num_elem, &(VUSE_OPS (stmt))); + return ret; } -/* Add DEF_P to the list of pointers to operands. */ +/* Takes elements from build_defs and turns them into def operands of STMT. + TODO -- Make build_defs VEC of tree *. */ static inline void -append_def (tree *def_p) +finalize_ssa_defs (tree stmt) { - VARRAY_PUSH_TREE_PTR (build_defs, def_p); -} + 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 && TREE_CODE (stmt) != GIMPLE_MODIFY_STMT) || num <= 1); -/* Add USE_P to the list of pointers to operands. */ + new_list.next = NULL; + last = &new_list; -static inline void -append_use (tree *use_p) -{ - VARRAY_PUSH_TREE_PTR (build_uses, use_p); -} + old_ops = DEF_OPS (stmt); + new_i = 0; -/* Add a new virtual may def for variable VAR to the build array. */ + /* 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; -static inline void -append_v_may_def (tree var) -{ - var_ann_t ann = get_var_ann (var); + /* 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; + } - /* Don't allow duplicate entries. */ - if (ann->in_v_may_def_list) - return; - ann->in_v_may_def_list = 1; + /* 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); - VARRAY_PUSH_TREE (build_v_may_defs, var); + /* 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 == num); + } +#endif } -/* Add VAR to the list of virtual uses. */ +/* Takes elements from build_uses and turns them into use operands of STMT. + TODO -- Make build_uses VEC of tree *. */ static inline void -append_vuse (tree var) +finalize_ssa_uses (tree stmt) { + unsigned new_i; + struct use_optype_d new_list; + use_optype_p old_ops, ptr, last; - /* Don't allow duplicate entries. */ - if (TREE_CODE (var) != SSA_NAME) - { - var_ann_t ann = get_var_ann (var); +#ifdef ENABLE_CHECKING + { + unsigned x; + unsigned num = VEC_length (tree, build_uses); - if (ann->in_vuse_list || ann->in_v_may_def_list) - return; - ann->in_vuse_list = 1; + /* 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 + + 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 = gimple_ssa_operands (cfun)->free_uses; + gimple_ssa_operands (cfun)->free_uses = old_ops; } - VARRAY_PUSH_TREE (build_vuses, var); + /* 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. */ + 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 } -/* Add VAR to the list of virtual must definitions for INFO. */ +/* Takes elements from BUILD_VDEFS and turns them into vdef operands of + STMT. FIXME, for now VDEF operators should have a single operand + in their RHS. */ static inline void -append_v_must_def (tree var) +finalize_ssa_vdefs (tree stmt) { - unsigned i; + unsigned new_i; + struct voptype_d new_list; + voptype_p old_ops, ptr, last; + stmt_ann_t ann = stmt_ann (stmt); - /* Don't allow duplicate entries. */ - for (i = 0; i < VARRAY_ACTIVE_SIZE (build_v_must_defs); i++) - if (var == VARRAY_TREE (build_v_must_defs, i)) - return; + /* Set the symbols referenced by STMT. */ + if (!bitmap_empty_p (build_stores)) + { + if (ann->operands.stores == NULL) + ann->operands.stores = BITMAP_ALLOC (&operands_bitmap_obstack); - VARRAY_PUSH_TREE (build_v_must_defs, var); -} + bitmap_copy (ann->operands.stores, build_stores); + } + else + BITMAP_FREE (ann->operands.stores); + + /* 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; -/* Create an operands cache for STMT, returning it in NEW_OPS. OLD_OPS are the - original operands, and if ANN is non-null, appropriate stmt flags are set - in the stmt's annotation. Note that some fields in old_ops may - change to NULL, although none of the memory they originally pointed to - will be destroyed. It is appropriate to call free_stmt_operands() on - the value returned in old_ops. + new_list.next = NULL; + last = &new_list; - The rationale for this: Certain optimizations wish to examine the difference - between new_ops and old_ops after processing. If a set of operands don't - change, new_ops will simply assume the pointer in old_ops, and the old_ops - pointer will be set to NULL, indicating no memory needs to be cleared. - Usage might appear something like: + old_ops = 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)); - old_ops_copy = old_ops = stmt_ann(stmt)->operands; - build_ssa_operands (stmt, NULL, &old_ops, &new_ops); - <* compare old_ops_copy and new_ops *> - free_ssa_operands (old_ops); */ + /* FIXME, for now each VDEF operator should have at most one + operand in their RHS. */ + gcc_assert (VDEF_NUM (old_ops) == 1); -static void -build_ssa_operands (tree stmt, stmt_ann_t ann, stmt_operands_p old_ops, - stmt_operands_p new_ops) -{ - enum tree_code code; - tree_ann_t saved_ann = stmt->common.ann; - - /* Replace stmt's annotation with the one passed in for the duration - of the operand building process. This allows "fake" stmts to be built - and not be included in other data structures which can be built here. */ - stmt->common.ann = (tree_ann_t) ann; - - /* Initially assume that the statement has no volatile operands, nor - makes aliased loads or stores. */ - if (ann) + 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) { - ann->has_volatile_ops = false; - ann->makes_aliased_stores = false; - ann->makes_aliased_loads = false; + for (ptr = old_ops; ptr; ptr = last) + { + last = ptr->next; + delink_imm_use (VDEF_OP_PTR (ptr, 0)); + add_vop_to_freelist (ptr); + } } - start_ssa_stmt_operands (); + /* Now set STMT's operands. */ + VDEF_OPS (stmt) = new_list.next; - code = TREE_CODE (stmt); - switch (code) +#ifdef ENABLE_CHECKING + { + unsigned x = 0; + for (ptr = 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 (tree stmt) +{ + unsigned new_i; + int old_i; + voptype_p old_ops, last; + VEC(tree,heap) *new_ops; + stmt_ann_t ann; + + /* Set the symbols referenced by STMT. */ + ann = stmt_ann (stmt); + if (!bitmap_empty_p (build_loads)) + { + if (ann->operands.loads == NULL) + ann->operands.loads = BITMAP_ALLOC (&operands_bitmap_obstack); + + bitmap_copy (ann->operands.loads, build_loads); + } + else + BITMAP_FREE (ann->operands.loads); + + /* 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 = 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); + VUSE_OPS (stmt) = NULL; + } + + /* If there are any operands, instantiate a VUSE operator for STMT. */ + if (new_ops) { - case MODIFY_EXPR: - /* First get operands from the RHS. For the LHS, we use a V_MAY_DEF if - either only part of LHS is modified or if the RHS might throw, - otherwise, use V_MUST_DEF. + 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); - ??? If it might throw, we should represent somehow that it is killed - on the fallthrough path. */ + VUSE_OPS (stmt) = last; + } + +#ifdef ENABLE_CHECKING + { + unsigned x; + + if (VUSE_OPS (stmt)) { - tree lhs = TREE_OPERAND (stmt, 0); - int lhs_flags = opf_is_def; + gcc_assert (VUSE_OPS (stmt)->next == NULL); + x = VUSE_NUM (VUSE_OPS (stmt)); + } + else + x = 0; + + gcc_assert (x == VEC_length (tree, build_vuses)); + } +#endif +} - get_expr_operands (stmt, &TREE_OPERAND (stmt, 1), opf_none); +/* Return a new VUSE operand vector for STMT. */ + +static void +finalize_ssa_vuses (tree stmt) +{ + unsigned num, num_vdefs; + unsigned vuse_index; - /* If the LHS is a VIEW_CONVERT_EXPR, it isn't changing whether - or not the entire LHS is modified; that depends on what's - inside the VIEW_CONVERT_EXPR. */ - if (TREE_CODE (lhs) == VIEW_CONVERT_EXPR) - lhs = TREE_OPERAND (lhs, 0); + /* 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_3 = VDEF + *p = *q; - if (TREE_CODE (lhs) != ARRAY_REF && TREE_CODE (lhs) != ARRAY_RANGE_REF - && TREE_CODE (lhs) != COMPONENT_REF - && TREE_CODE (lhs) != BIT_FIELD_REF - && TREE_CODE (lhs) != REALPART_EXPR - && TREE_CODE (lhs) != IMAGPART_EXPR) - lhs_flags |= opf_kill_def; + The VUSE is superfluous because it is implied by the + VDEF operator. */ + num = VEC_length (tree, build_vuses); + num_vdefs = VEC_length (tree, build_vdefs); - get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), lhs_flags); + 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++; } - break; - case COND_EXPR: - get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_none); - break; + 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 (tree stmt) +{ + finalize_ssa_defs (stmt); + finalize_ssa_uses (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 || ann->in_vdef_list) + 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. */ + +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 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 + && !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) + && !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 the statement as having memory operands. */ + s_ann->references_memory = true; + + /* 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 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 + GIMPLE_MODIFY_STMT, 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; + + aliases = v_ann->may_aliases; + if (aliases == NULL) + { + if (s_ann && !gimple_aliases_computed_p (cfun)) + s_ann->has_volatile_ops = true; + /* The variable is not aliased or it is an alias tag. */ + if (flags & opf_def) + append_vdef (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_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_vdef (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)) + { + append_vdef (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) +{ + tree var, sym; + var_ann_t v_ann; + + gcc_assert (SSA_VAR_P (*var_p) && s_ann); + + 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)) + s_ann->has_volatile_ops = 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, 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); + + s_ann->references_memory = true; + if (s_ann && TREE_THIS_VOLATILE (expr)) + s_ann->has_volatile_ops = 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, 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); + /* Aliasing information is missing; mark statement as volatile so we + won't optimize it out too actively. */ + else if (s_ann && !gimple_aliases_computed_p (cfun) + && (flags & opf_def)) + s_ann->has_volatile_ops = 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. */ + 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_use); +} + + +/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ + +static void +get_tmr_operands (tree stmt, tree expr, int flags) +{ + tree tag, ref; + HOST_WIDE_INT offset, size, maxsize; + subvar_t svars, sv; + stmt_ann_t s_ann = stmt_ann (stmt); + + /* This statement references memory. */ + s_ann->references_memory = 1; + + /* 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)) + add_to_addressable_set (TMR_SYMBOL (expr), &s_ann->addresses_taken); + + tag = TMR_TAG (expr); + if (!tag) + { + /* Something weird, so ensure that we will be careful. */ + s_ann->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)) + add_stmt_operand (&sv->var, s_ann, 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 (gimple_global_var (cfun)) + { + tree var = gimple_global_var (cfun); + add_stmt_operand (&var, s_ann, opf_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 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); + 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_use); + 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_use); + else + clobber_stats.static_read_clobbers_avoided++; + } + else + add_virtual_operand (var, s_ann, 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 (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 (gimple_global_var (cfun)) + { + tree var = gimple_global_var (cfun); + add_stmt_operand (&var, s_ann, opf_use); + 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 (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 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_use | opf_implicit); + } +} + + +/* 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); + stmt_ann_t ann = stmt_ann (stmt); + + ann->references_memory = 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 (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_use); - case SWITCH_EXPR: - get_expr_operands (stmt, &SWITCH_COND (stmt), opf_none); - break; + for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op)) + get_expr_operands (stmt, &TREE_VALUE (op), opf_use); - case ASM_EXPR: - get_asm_expr_operands (stmt); - break; + get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_use); +} - 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; +/* Scan operands in the ASM_EXPR stmt referred to in INFO. */ - case LABEL_EXPR: - get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_none); - break; +static void +get_asm_expr_operands (tree stmt) +{ + stmt_ann_t s_ann; + int i, noutputs; + const char **oconstraints; + const char *constraint; + bool allows_mem, allows_reg, is_inout; + tree link; - /* These nodes contain no variable references. */ - 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: - break; + s_ann = stmt_ann (stmt); + noutputs = list_length (ASM_OUTPUTS (stmt)); + oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *)); - default: - /* Notice that if get_expr_operands tries to use &STMT as the operand - pointer (which may only happen for USE operands), we will abort in - append_use. 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; - } + /* Gather all output operands. */ + 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); - finalize_ssa_stmt_operands (stmt, old_ops, new_ops); - stmt->common.ann = saved_ann; -} + /* 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); + } -/* Free any operands vectors in OPS. */ + get_expr_operands (stmt, &TREE_VALUE (link), opf_def); + } -static void -free_ssa_operands (stmt_operands_p ops) -{ - if (ops->def_ops) - free_defs (&(ops->def_ops)); - if (ops->use_ops) - free_uses (&(ops->use_ops)); - if (ops->vuse_ops) - free_vuses (&(ops->vuse_ops)); - if (ops->v_may_def_ops) - free_v_may_defs (&(ops->v_may_def_ops)); - if (ops->v_must_def_ops) - free_v_must_defs (&(ops->v_must_def_ops)); -} + /* Gather all input operands. */ + 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 the operands of statement STMT. Note that repeated calls to - get_stmt_operands for the same statement will do nothing until the - statement is marked modified by a call to modify_stmt(). */ + get_expr_operands (stmt, &TREE_VALUE (link), 0); + } -void -get_stmt_operands (tree stmt) -{ - stmt_ann_t ann; - stmt_operands_t old_operands; + /* Clobber all memory and addressable symbols 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; - /* The optimizers cannot handle statements that are nothing but a - _DECL. This indicates a bug in the gimplifier. */ - gcc_assert (!SSA_VAR_P (stmt)); + s_ann->references_memory = true; - /* Ignore error statements. */ - if (TREE_CODE (stmt) == ERROR_MARK) - return; + EXECUTE_IF_SET_IN_BITMAP (gimple_call_clobbered_vars (cfun), 0, i, bi) + { + tree var = referenced_var (i); + add_stmt_operand (&var, s_ann, opf_def | opf_implicit); + } - ann = get_stmt_ann (stmt); + EXECUTE_IF_SET_IN_BITMAP (gimple_addressable_vars (cfun), 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 + to avoid confusing the back-end. */ + if (var_can_have_subvars (var) + && get_subvars_for_var (var) != NULL) + continue; + + add_stmt_operand (&var, s_ann, opf_def | opf_implicit); + } + break; + } +} - /* If the statement has not been modified, the operands are still valid. */ - if (!ann->modified) - return; - timevar_push (TV_TREE_OPS); +/* Scan operands for the assignment expression EXPR in statement STMT. */ - old_operands = ann->operands; - memset (&(ann->operands), 0, sizeof (stmt_operands_t)); +static void +get_modify_stmt_operands (tree stmt, tree expr) +{ + /* First get operands from the RHS. */ + get_expr_operands (stmt, &GIMPLE_STMT_OPERAND (expr, 1), opf_use); - build_ssa_operands (stmt, ann, &old_operands, &(ann->operands)); - free_ssa_operands (&old_operands); + /* For the LHS, use a regular definition (opf_def) for GIMPLE + registers. If the LHS is a store to memory, we will need + a preserving definition (VDEF). - /* Clear the modified bit for STMT. Subsequent calls to - get_stmt_operands for this statement will do nothing until the - statement is marked modified by a call to modify_stmt(). */ - ann->modified = 0; + 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 VDEF operators. - timevar_pop (TV_TREE_OPS); + We used to distinguish between preserving and killing definitions. + We always emit preserving definitions now. */ + get_expr_operands (stmt, &GIMPLE_STMT_OPERAND (expr, 0), opf_def); } -/* Recursively scan the expression pointed by EXPR_P in statement referred to - by INFO. FLAGS is one of the OPF_* constants modifying how to interpret the - operands found. */ +/* 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) @@ -1037,7 +2035,7 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) tree expr = *expr_p; stmt_ann_t s_ann = stmt_ann (stmt); - if (expr == NULL || expr == error_mark_node) + if (expr == NULL) return; code = TREE_CODE (expr); @@ -1046,36 +2044,54 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) switch (code) { case ADDR_EXPR: - /* We could have the address of a component, array member, - etc which has interesting variable references. */ /* Taking the address of a variable does not represent a - reference to it, but the fact that the stmt takes its address will be - of interest to some passes (e.g. alias resolution). */ - add_stmt_operand (expr_p, s_ann, 0); + 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 the address is invariant, there may be no interesting + variable references inside. */ if (is_gimple_min_invariant (expr)) return; - /* 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). */ + /* 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: - case CONST_DECL: - /* If we found a variable, add it to DEFS or USES depending - on the operand flags. */ - add_stmt_operand (expr_p, s_ann, flags); - return; + { + 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); @@ -1083,59 +2099,82 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) case ALIGN_INDIRECT_REF: case INDIRECT_REF: - get_indirect_ref_operands (stmt, expr, flags); + get_indirect_ref_operands (stmt, expr, flags, NULL_TREE, 0, -1, true); return; - case ARRAY_REF: - case ARRAY_RANGE_REF: - /* Treat array references as references to the virtual variable - representing the array. The virtual variable for an ARRAY_REF - is the VAR_DECL for the array. */ - - /* Add the virtual variable for the ARRAY_REF to VDEFS or VUSES - according to the value of IS_DEF. Recurse if the LHS of the - ARRAY_REF node is not a regular variable. */ - if (SSA_VAR_P (TREE_OPERAND (expr, 0))) - add_stmt_operand (expr_p, s_ann, flags); - else - get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); - - 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); + 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: - /* Similarly to arrays, references to compound variables (complex - types and structures/unions) are globbed. - - FIXME: This means that + { + 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); - a.x = 6; - a.y = 7; - foo (a.x, a.y); + for (sv = svars; sv; sv = sv->next) + { + bool exact; + + if (overlap_subvar (offset, maxsize, sv->var, &exact)) + { + int subvar_flags = flags; + none = false; + add_stmt_operand (&sv->var, s_ann, subvar_flags); + } + } - will not be constant propagated because the two partial - definitions to 'a' will kill each other. Note that SRA may be - able to fix this problem if 'a' can be scalarized. */ + 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; + } - /* If the LHS of the compound reference is not a regular variable, - recurse to keep looking for more operands in the subexpression. */ - if (SSA_VAR_P (TREE_OPERAND (expr, 0))) - add_stmt_operand (expr_p, s_ann, flags); - else + /* 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); + + 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_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); + } - if (code == COMPONENT_REF) - get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); - return; + 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, 1), opf_use); get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); return; @@ -1145,48 +2184,32 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) 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); + 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 MODIFY_EXPR: - { - int subflags; - tree op; - - get_expr_operands (stmt, &TREE_OPERAND (expr, 1), opf_none); - - op = TREE_OPERAND (expr, 0); - if (TREE_CODE (op) == WITH_SIZE_EXPR) - op = TREE_OPERAND (expr, 0); - if (TREE_CODE (op) == ARRAY_REF - || TREE_CODE (op) == ARRAY_RANGE_REF - || TREE_CODE (op) == COMPONENT_REF - || TREE_CODE (op) == REALPART_EXPR - || TREE_CODE (op) == IMAGPART_EXPR) - subflags = opf_is_def; - else - subflags = opf_is_def | opf_kill_def; - - get_expr_operands (stmt, &TREE_OPERAND (expr, 0), subflags); - return; - } + case GIMPLE_MODIFY_STMT: + get_modify_stmt_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; - tree t; - for (t = TREE_OPERAND (expr, 0); t ; t = TREE_CHAIN (t)) - get_expr_operands (stmt, &TREE_VALUE (t), opf_none); + for (idx = 0; + VEC_iterate (constructor_elt, CONSTRUCTOR_ELTS (expr), idx, ce); + idx++) + get_expr_operands (stmt, &ce->value, opf_use); return; } - case TRUTH_NOT_EXPR: case BIT_FIELD_REF: + case TRUTH_NOT_EXPR: case VIEW_CONVERT_EXPR: do_unary: get_expr_operands (stmt, &TREE_OPERAND (expr, 0), flags); @@ -1197,44 +2220,15 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) case TRUTH_XOR_EXPR: case COMPOUND_EXPR: case OBJ_TYPE_REF: + case ASSERT_EXPR: do_binary: { - tree op0 = TREE_OPERAND (expr, 0); - tree op1 = TREE_OPERAND (expr, 1); - - /* If it would be profitable to swap the operands, then do so to - canonicalize the statement, enabling better optimization. - - By placing canonicalization of such expressions here we - transparently keep statements in canonical form, even - when the statement is modified. */ - if (tree_swap_operands_p (op0, op1, false)) - { - /* For relationals we need to swap the operands - and change the code. */ - if (code == LT_EXPR - || code == GT_EXPR - || code == LE_EXPR - || code == GE_EXPR) - { - TREE_SET_CODE (expr, swap_tree_comparison (code)); - TREE_OPERAND (expr, 0) = op1; - TREE_OPERAND (expr, 1) = op0; - } - - /* For a commutative operator we can just swap the operands. */ - else if (commutative_tree_code (code)) - { - TREE_OPERAND (expr, 0) = op1; - TREE_OPERAND (expr, 1) = op0; - } - } - 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); @@ -1248,6 +2242,16 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) 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; @@ -1265,622 +2269,773 @@ get_expr_operands (tree stmt, tree *expr_p, int flags) fprintf (stderr, "unhandled expression in get_expr_operands():\n"); debug_tree (expr); fputs ("\n", stderr); - internal_error ("internal error"); #endif gcc_unreachable (); } -/* Scan operands in the ASM_EXPR stmt referred to in INFO. */ +/* Parse STMT looking for operands. When finished, the various + build_* operand vectors will have potential operands in them. */ static void -get_asm_expr_operands (tree stmt) +parse_ssa_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; + enum tree_code code; - for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link)) + code = TREE_CODE (stmt); + switch (code) { - oconstraints[i] = constraint - = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); - 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)) - note_addressable (t, s_ann); - } - - get_expr_operands (stmt, &TREE_VALUE (link), opf_is_def); - } + case GIMPLE_MODIFY_STMT: + get_modify_stmt_operands (stmt, stmt); + break; - 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); + case COND_EXPR: + get_expr_operands (stmt, &COND_EXPR_COND (stmt), opf_use); + break; - /* 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)) - note_addressable (t, s_ann); - } + case SWITCH_EXPR: + get_expr_operands (stmt, &SWITCH_COND (stmt), opf_use); + break; - get_expr_operands (stmt, &TREE_VALUE (link), 0); - } + case ASM_EXPR: + get_asm_expr_operands (stmt); + break; + case RETURN_EXPR: + get_expr_operands (stmt, &TREE_OPERAND (stmt, 0), opf_use); + break; - /* 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; + case GOTO_EXPR: + get_expr_operands (stmt, &GOTO_DESTINATION (stmt), opf_use); + break; - /* 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); - } + case LABEL_EXPR: + get_expr_operands (stmt, &LABEL_EXPR_LABEL (stmt), opf_use); + break; - /* Now clobber all addressables. */ - EXECUTE_IF_SET_IN_BITMAP (addressable_vars, 0, i, bi) - { - tree var = referenced_var (i); - add_stmt_operand (&var, s_ann, opf_is_def); - } + 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; - 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_use); + break; + } } -/* A subroutine of get_expr_operands to handle INDIRECT_REF, - ALIGN_INDIRECT_REF and MISALIGNED_INDIRECT_REF. */ + +/* Create an operands cache for STMT. */ static void -get_indirect_ref_operands (tree stmt, tree expr, int flags) +build_ssa_operands (tree stmt) { - tree *pptr = &TREE_OPERAND (expr, 0); - tree ptr = *pptr; - stmt_ann_t s_ann = stmt_ann (stmt); + stmt_ann_t ann = get_stmt_ann (stmt); + + /* Initially assume that the statement has no volatile operands and + makes no memory references. */ + ann->has_volatile_ops = false; + ann->references_memory = false; + /* Just clear the bitmap so we don't end up reallocating it over and over. */ + if (ann->addresses_taken) + bitmap_clear (ann->addresses_taken); - /* Stores into INDIRECT_REF operands are never killing definitions. */ - flags &= ~opf_kill_def; + 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); + + if (ann->addresses_taken && bitmap_empty_p (ann->addresses_taken)) + ann->addresses_taken = NULL; + /* For added safety, assume that statements with volatile operands + also reference memory. */ + if (ann->has_volatile_ops) + ann->references_memory = 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_stmt_operand (&pi->name_mem_tag, s_ann, flags); - } - else - { - /* If PTR is not an SSA_NAME or it doesn't have a name - tag, use its type memory tag. */ - var_ann_t v_ann; +/* Free any operands vectors in OPS. */ - /* 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); - } +void +free_ssa_operands (stmt_operands_p ops) +{ + ops->def_ops = NULL; + ops->use_ops = NULL; + ops->vdef_ops = NULL; + ops->vuse_ops = NULL; + BITMAP_FREE (ops->loads); + BITMAP_FREE (ops->stores); +} - if (TREE_CODE (ptr) == SSA_NAME) - ptr = SSA_NAME_VAR (ptr); - v_ann = var_ann (ptr); - if (v_ann->type_mem_tag) - add_stmt_operand (&v_ann->type_mem_tag, s_ann, flags); - } - } - /* 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. */ - else if (TREE_CODE (ptr) == INTEGER_CST) - { - if (s_ann) - s_ann->has_volatile_ops = true; - return; - } +/* Get the operands of statement STMT. */ + +void +update_stmt_operands (tree stmt) +{ + stmt_ann_t ann = get_stmt_ann (stmt); - /* Everything else *should* have been folded elsewhere, but users - are smarter than we in finding ways to write invalid code. We - cannot just abort here. If we were absolutely certain that we - do handle all valid cases, then we could just do nothing here. - That seems optimistic, so attempt to do something logical... */ - else if ((TREE_CODE (ptr) == PLUS_EXPR || TREE_CODE (ptr) == MINUS_EXPR) - && TREE_CODE (TREE_OPERAND (ptr, 0)) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (ptr, 1)) == INTEGER_CST) - { - /* Make sure we know the object is addressable. */ - pptr = &TREE_OPERAND (ptr, 0); - add_stmt_operand (pptr, s_ann, 0); + /* If update_stmt_operands is called before SSA is initialized, do + nothing. */ + if (!ssa_operands_active ()) + return; - /* Mark the object itself with a VUSE. */ - pptr = &TREE_OPERAND (*pptr, 0); - get_expr_operands (stmt, pptr, flags); - 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)); - /* Ok, this isn't even is_gimple_min_invariant. Something's broke. */ - else - gcc_unreachable (); + timevar_push (TV_TREE_OPS); + + gcc_assert (ann->modified); + build_ssa_operands (stmt); + ann->modified = 0; - /* Add a USE operand for the base pointer. */ - get_expr_operands (stmt, pptr, opf_none); + timevar_pop (TV_TREE_OPS); } -/* A subroutine of get_expr_operands to handle CALL_EXPR. */ -static void -get_call_expr_operands (tree stmt, tree expr) +/* Copies virtual operands from SRC to DST. */ + +void +copy_virtual_operands (tree dest, tree src) { - tree op; - int call_flags = call_expr_flags (expr); + int i, n; + voptype_p src_vuses, dest_vuses; + voptype_p src_vdefs, dest_vdefs; + struct voptype_d vuse; + struct voptype_d vdef; + stmt_ann_t dest_ann; - /* 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)) + VDEF_OPS (dest) = NULL; + VUSE_OPS (dest) = NULL; + + dest_ann = get_stmt_ann (dest); + BITMAP_FREE (dest_ann->operands.loads); + BITMAP_FREE (dest_ann->operands.stores); + + if (LOADED_SYMS (src)) { - /* A 'pure' or a 'const' functions never call clobber 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); - else if (!(call_flags & ECF_CONST)) - add_call_read_ops (stmt); + dest_ann->operands.loads = BITMAP_ALLOC (&operands_bitmap_obstack); + bitmap_copy (dest_ann->operands.loads, LOADED_SYMS (src)); } - /* Find uses in the called function. */ - get_expr_operands (stmt, &TREE_OPERAND (expr, 0), opf_none); + if (STORED_SYMS (src)) + { + dest_ann->operands.stores = BITMAP_ALLOC (&operands_bitmap_obstack); + bitmap_copy (dest_ann->operands.stores, STORED_SYMS (src)); + } - for (op = TREE_OPERAND (expr, 1); op; op = TREE_CHAIN (op)) - get_expr_operands (stmt, &TREE_VALUE (op), opf_none); + /* Copy all the VUSE operators and corresponding operands. */ + dest_vuses = &vuse; + for (src_vuses = 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)); - get_expr_operands (stmt, &TREE_OPERAND (expr, 2), opf_none); + if (VUSE_OPS (dest) == NULL) + VUSE_OPS (dest) = vuse.next; + } + /* Copy all the VDEF operators and corresponding operands. */ + dest_vdefs = &vdef; + for (src_vdefs = 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 (VDEF_OPS (dest) == NULL) + VDEF_OPS (dest) = vdef.next; + } } -/* Add *VAR_P to the appropriate operand array for INFO. 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. */ +/* 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. */ -static void -add_stmt_operand (tree *var_p, stmt_ann_t s_ann, int flags) +void +create_ssa_artificial_load_stmt (tree new_stmt, tree old_stmt) { - bool is_real_op; - tree var, sym; - var_ann_t v_ann; - - var = *var_p; - STRIP_NOPS (var); + tree op; + ssa_op_iter iter; + use_operand_p use_p; + unsigned i; - /* If the operand is an ADDR_EXPR, add its operand to the list of - variables that have had their address taken in this statement. */ - if (TREE_CODE (var) == ADDR_EXPR) - { - note_addressable (TREE_OPERAND (var, 0), s_ann); - return; - } + get_stmt_ann (new_stmt); - /* If the original variable is not a scalar, it will be added to the list - of virtual operands. In that case, use its base symbol as the virtual - variable representing it. */ - is_real_op = is_gimple_reg (var); - if (!is_real_op && !DECL_P (var)) - var = get_virtual_var (var); + /* Process NEW_STMT looking for operands. */ + start_ssa_stmt_operands (); + parse_ssa_operands (new_stmt); - /* If VAR is not a variable that we care to optimize, do nothing. */ - if (var == NULL_TREE || !SSA_VAR_P (var)) - return; + 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_vuses, i, op); i++) + if (TREE_CODE (op) != SSA_NAME) + var_ann (op)->in_vdef_list = false; - sym = (TREE_CODE (var) == SSA_NAME ? SSA_NAME_VAR (var) : var); - v_ann = var_ann (sym); + /* Remove any virtual operands that were found. */ + VEC_truncate (tree, build_vdefs, 0); + VEC_truncate (tree, build_vuses, 0); - /* 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; + /* 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); - 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 - { - varray_type aliases; + finalize_ssa_stmt_operands (new_stmt); - /* 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; + /* 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); +} - 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) - { - /* Only regular variables may get a V_MUST_DEF - operand. */ - gcc_assert (v_ann->mem_tag_kind == NOT_A_TAG); - /* V_MUST_DEF for non-aliased, non-GIMPLE register - variable definitions. */ - 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); - if (s_ann && v_ann->is_alias_tag) - s_ann->makes_aliased_loads = 1; - } - } - else - { - size_t i; +/* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done + to test the validity of the swap operation. */ - /* The variable is aliased. Add its aliases to the virtual - operands. */ - gcc_assert (VARRAY_ACTIVE_SIZE (aliases) != 0); +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; - if (flags & opf_is_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. */ - if (v_ann->is_alias_tag) - append_v_may_def (var); - - for (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++) - append_v_may_def (VARRAY_TREE (aliases, i)); - - if (s_ann) - s_ann->makes_aliased_stores = 1; - } - else - { - /* Similarly, append a virtual uses for VAR itself, when - it is an alias tag. */ - if (v_ann->is_alias_tag) - append_vuse (var); + /* 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 (i = 0; i < VARRAY_ACTIVE_SIZE (aliases); i++) - append_vuse (VARRAY_TREE (aliases, i)); + for (ptr = USE_OPS (stmt); ptr; ptr = ptr->next) + if (USE_OP_PTR (ptr)->use == exp1) + { + use1 = ptr; + break; + } - if (s_ann) - s_ann->makes_aliased_loads = 1; - } + /* 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; } -/* Record that VAR had its address taken in the statement with annotations - S_ANN. */ +/* 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. */ -static void -note_addressable (tree var, stmt_ann_t s_ann) +void +add_to_addressable_set (tree ref, bitmap *addresses_taken) { - if (!s_ann) - return; + tree var; + subvar_t svars; + + gcc_assert (addresses_taken); - var = get_base_address (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 (s_ann->addresses_taken == NULL) - s_ann->addresses_taken = BITMAP_GGC_ALLOC (); - bitmap_set_bit (s_ann->addresses_taken, var_ann (var)->uid); + 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; + } } } -/* Add clobbering definitions for .GLOBAL_VAR or for each of the call - clobbered variables in the function. */ +/* 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. */ -static void -add_call_clobber_ops (tree stmt) +bool +verify_imm_links (FILE *f, tree var) { - unsigned i; - tree t; - bitmap_iterator bi; - stmt_ann_t s_ann = stmt_ann (stmt); - struct stmt_ann_d empty_ann; + use_operand_p ptr, prev, list; + int count; - /* Functions that are not const, pure or never return may clobber - call-clobbered variables. */ - if (s_ann) - s_ann->makes_clobbering_call = true; + gcc_assert (TREE_CODE (var) == SSA_NAME); - /* 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) + list = &(SSA_NAME_IMM_USE_NODE (var)); + gcc_assert (list->use == NULL); + + if (list->prev == NULL) { - add_stmt_operand (&global_var, s_ann, opf_is_def); - return; + gcc_assert (list->next == NULL); + return false; } - /* If cache is valid, copy the elements into the build vectors. */ - if (ssa_call_clobbered_cache_valid) + prev = list; + count = 0; + for (ptr = list->next; ptr != list; ) { - for (i = 0; i < VARRAY_ACTIVE_SIZE (clobbered_vuses); i++) - { - t = VARRAY_TREE (clobbered_vuses, i); - gcc_assert (TREE_CODE (t) != SSA_NAME); - var_ann (t)->in_vuse_list = 1; - VARRAY_PUSH_TREE (build_vuses, t); - } - for (i = 0; i < VARRAY_ACTIVE_SIZE (clobbered_v_may_defs); i++) - { - t = VARRAY_TREE (clobbered_v_may_defs, i); - gcc_assert (TREE_CODE (t) != SSA_NAME); - var_ann (t)->in_v_may_def_list = 1; - VARRAY_PUSH_TREE (build_v_may_defs, t); - } - if (s_ann) - { - s_ann->makes_aliased_loads = clobbered_aliased_loads; - s_ann->makes_aliased_stores = clobbered_aliased_stores; - } - return; + 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; } - memset (&empty_ann, 0, sizeof (struct stmt_ann_d)); - - /* Add a V_MAY_DEF operand for every call clobbered variable. */ - EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi) + /* Verify list in the other direction. */ + prev = list; + for (ptr = list->prev; ptr != list; ) { - tree var = referenced_var (i); - if (TREE_READONLY (var) - && (TREE_STATIC (var) || DECL_EXTERNAL (var))) - add_stmt_operand (&var, &empty_ann, opf_none); - else - add_stmt_operand (&var, &empty_ann, opf_is_def); + if (prev != ptr->next) + goto error; + prev = ptr; + ptr = ptr->prev; + if (count-- < 0) + goto error; } - clobbered_aliased_loads = empty_ann.makes_aliased_loads; - clobbered_aliased_stores = empty_ann.makes_aliased_stores; + if (count != 0) + goto error; - /* Set the flags for a stmt's annotation. */ - if (s_ann) + return false; + + error: + if (ptr->stmt && stmt_modified_p (ptr->stmt)) { - s_ann->makes_aliased_loads = empty_ann.makes_aliased_loads; - s_ann->makes_aliased_stores = empty_ann.makes_aliased_stores; + 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)); - /* Prepare empty cache vectors. */ - if (clobbered_v_may_defs) + FOR_EACH_IMM_USE_FAST (use_p, iter, var) { - VARRAY_POP_ALL (clobbered_vuses); - VARRAY_POP_ALL (clobbered_v_may_defs); + 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|TDF_MEMSYMS); + else + print_generic_stmt (file, USE_STMT (use_p), TDF_SLIM); } - else + 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++) { - VARRAY_TREE_INIT (clobbered_v_may_defs, 10, "clobbered_v_may_defs"); - VARRAY_TREE_INIT (clobbered_vuses, 10, "clobbered_vuses"); + var = ssa_name(x); + if (!var) + continue; + dump_immediate_uses_for (file, var); } +} - /* Now fill the clobbered cache with the values that have been found. */ - for (i = 0; i < VARRAY_ACTIVE_SIZE (build_vuses); i++) - VARRAY_PUSH_TREE (clobbered_vuses, VARRAY_TREE (build_vuses, i)); - for (i = 0; i < VARRAY_ACTIVE_SIZE (build_v_may_defs); i++) - VARRAY_PUSH_TREE (clobbered_v_may_defs, VARRAY_TREE (build_v_may_defs, i)); - ssa_call_clobbered_cache_valid = true; +/* Dump def-use edges on stderr. */ + +void +debug_immediate_uses (void) +{ + dump_immediate_uses (stderr); } -/* Add VUSE operands for .GLOBAL_VAR or all call clobbered variables in the - function. */ +/* Dump def-use edges on stderr. */ -static void -add_call_read_ops (tree stmt) +void +debug_immediate_uses_for (tree var) { - unsigned i; - tree t; - bitmap_iterator bi; - stmt_ann_t s_ann = stmt_ann (stmt); - struct stmt_ann_d empty_ann; + dump_immediate_uses_for (stderr, var); +} - /* 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; - } + +/* 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 (tree *stmt_p) +{ + tree stmt; + scb_t buf; - /* If cache is valid, copy the elements into the build vector. */ - if (ssa_ro_call_cache_valid) + stmt = *stmt_p; + + /* It makes no sense to keep track of PHI nodes. */ + if (TREE_CODE (stmt) == PHI_NODE) + return; + + buf = xmalloc (sizeof *buf); + memset (buf, 0, sizeof *buf); + + buf->stmt_p = stmt_p; + + if (stmt_references_memory_p (stmt)) { - for (i = 0; i < VARRAY_ACTIVE_SIZE (ro_call_vuses); i++) + tree op; + ssa_op_iter i; + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VUSE) { - t = VARRAY_TREE (ro_call_vuses, i); - gcc_assert (TREE_CODE (t) != SSA_NAME); - var_ann (t)->in_vuse_list = 1; - VARRAY_PUSH_TREE (build_vuses, t); + 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)); } - if (s_ann) - s_ann->makes_aliased_loads = ro_call_aliased_loads; - return; } - memset (&empty_ann, 0, sizeof (struct stmt_ann_d)); + VEC_safe_push (scb_t, heap, scb_stack, buf); +} - /* Add a VUSE for each call-clobbered variable. */ - EXECUTE_IF_SET_IN_BITMAP (call_clobbered_vars, 0, i, bi) - { - tree var = referenced_var (i); - add_stmt_operand (&var, &empty_ann, opf_none); - } - ro_call_aliased_loads = empty_ann.makes_aliased_loads; - if (s_ann) - s_ann->makes_aliased_loads = empty_ann.makes_aliased_loads; +/* 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). */ - /* Prepare empty cache vectors. */ - if (ro_call_vuses) - VARRAY_POP_ALL (ro_call_vuses); - else - VARRAY_TREE_INIT (ro_call_vuses, 10, "ro_call_vuses"); +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 t2 = BITMAP_ALLOC (NULL); - /* Now fill the clobbered cache with the values that have been found. */ - for (i = 0; i < VARRAY_ACTIVE_SIZE (build_vuses); i++) - VARRAY_PUSH_TREE (ro_call_vuses, VARRAY_TREE (build_vuses, i)); + bitmap_and_compl (t1, s1, s2); + bitmap_and_compl (t2, s2, s1); + bitmap_ior_into (t1, t2); + mark_set_for_renaming (t1); - ssa_ro_call_cache_valid = true; + BITMAP_FREE (t1); + BITMAP_FREE (t2); + } } -/* Copies virtual operands from SRC to DST. */ + +/* 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 -copy_virtual_operands (tree dst, tree src) +pop_stmt_changes (tree *stmt_p) { - unsigned i; - vuse_optype vuses = STMT_VUSE_OPS (src); - v_may_def_optype v_may_defs = STMT_V_MAY_DEF_OPS (src); - v_must_def_optype v_must_defs = STMT_V_MUST_DEF_OPS (src); - vuse_optype *vuses_new = &stmt_ann (dst)->operands.vuse_ops; - v_may_def_optype *v_may_defs_new = &stmt_ann (dst)->operands.v_may_def_ops; - v_must_def_optype *v_must_defs_new = &stmt_ann (dst)->operands.v_must_def_ops; - - if (vuses) - { - *vuses_new = allocate_vuse_optype (NUM_VUSES (vuses)); - for (i = 0; i < NUM_VUSES (vuses); i++) - SET_VUSE_OP (*vuses_new, i, VUSE_OP (vuses, i)); - } + tree op, 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 (TREE_CODE (stmt) == PHI_NODE) + return; + + buf = VEC_pop (scb_t, scb_stack); + gcc_assert (stmt_p == buf->stmt_p); - if (v_may_defs) + /* 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 (stmt_references_memory_p (stmt)) { - *v_may_defs_new = allocate_v_may_def_optype (NUM_V_MAY_DEFS (v_may_defs)); - for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) + tree op; + ssa_op_iter i; + + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VUSE) { - SET_V_MAY_DEF_OP (*v_may_defs_new, i, V_MAY_DEF_OP (v_may_defs, i)); - SET_V_MAY_DEF_RESULT (*v_may_defs_new, i, - V_MAY_DEF_RESULT (v_may_defs, i)); + 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)); } - } - if (v_must_defs) - { - *v_must_defs_new = allocate_v_must_def_optype (NUM_V_MUST_DEFS (v_must_defs)); - for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++) + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_VDEF) { - SET_V_MUST_DEF_RESULT (*v_must_defs_new, i, V_MUST_DEF_RESULT (v_must_defs, i)); - SET_V_MUST_DEF_KILL (*v_must_defs_new, i, V_MUST_DEF_KILL (v_must_defs, i)); + 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 + 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); } -/* 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. */ +/* 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 -create_ssa_artficial_load_stmt (stmt_operands_p old_ops, tree new_stmt) +discard_stmt_changes (tree *stmt_p) { - stmt_ann_t ann; - tree op; - stmt_operands_t tmp; - unsigned j; + scb_t buf; + tree stmt; + + /* It makes no sense to keep track of PHI nodes. */ + stmt = *stmt_p; + if (TREE_CODE (stmt) == PHI_NODE) + return; - memset (&tmp, 0, sizeof (stmt_operands_t)); - ann = get_stmt_ann (new_stmt); + buf = VEC_pop (scb_t, scb_stack); + gcc_assert (stmt_p == buf->stmt_p); - /* Free operands just in case is was an existing stmt. */ - free_ssa_operands (&(ann->operands)); + /* Free memory used by the buffer. */ + BITMAP_FREE (buf->loads); + BITMAP_FREE (buf->stores); + buf->stmt_p = NULL; + free (buf); +} - build_ssa_operands (new_stmt, NULL, &tmp, &(ann->operands)); - free_vuses (&(ann->operands.vuse_ops)); - free_v_may_defs (&(ann->operands.v_may_def_ops)); - free_v_must_defs (&(ann->operands.v_must_def_ops)); - - /* 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 (j = 0; j < NUM_V_MAY_DEFS (old_ops->v_may_def_ops); j++) + +/* Returns true if statement STMT may access memory. */ + +bool +stmt_references_memory_p (tree stmt) +{ + if (!gimple_ssa_operands (cfun)->ops_active || TREE_CODE (stmt) == PHI_NODE) + return false; + + return stmt_ann (stmt)->references_memory; +} + + +/* Return the memory partition tag (MPT) associated with memory + symbol SYM. From a correctness standpoint, memory partitions can + be assigned in any arbitrary fashion as long as this rule is + observed: Given two memory partitions MPT.i and MPT.j, they must + not contain symbols in common. + + Memory partitions are used when putting the program into Memory-SSA + form. In particular, in Memory-SSA PHI nodes are not computed for + individual memory symbols. They are computed for memory + partitions. This reduces the amount of PHI nodes in the SSA graph + at the expense of precision (i.e., it makes unrelated stores affect + each other). + + However, it is possible to increase precision by changing this + partitioning scheme. For instance, if the partitioning scheme is + such that get_mpt_for is the identity function (that is, + get_mpt_for (s) = s), this will result in ultimate precision at the + expense of huge SSA webs. + + At the other extreme, a partitioning scheme that groups all the + symbols in the same set results in minimal SSA webs and almost + total loss of precision. */ + +tree +get_mpt_for (tree sym) +{ + tree mpt; + + /* Don't create a new tag unnecessarily. */ + mpt = memory_partition (sym); + if (mpt == NULL_TREE) { - op = V_MAY_DEF_RESULT (old_ops->v_may_def_ops, j); - append_vuse (op); + mpt = create_tag_raw (MEMORY_PARTITION_TAG, TREE_TYPE (sym), "MPT"); + TREE_ADDRESSABLE (mpt) = 0; + MTAG_GLOBAL (mpt) = 1; + add_referenced_var (mpt); + VEC_safe_push (tree, heap, gimple_ssa_operands (cfun)->mpt_table, mpt); + MPT_SYMBOLS (mpt) = BITMAP_ALLOC (&operands_bitmap_obstack); + set_memory_partition (sym, mpt); } - - for (j = 0; j < NUM_V_MUST_DEFS (old_ops->v_must_def_ops); j++) + + return mpt; +} + + +/* Dump memory partition information to FILE. */ + +void +dump_memory_partitions (FILE *file) +{ + unsigned i, npart; + unsigned long nsyms; + tree mpt; + + fprintf (file, "\nMemory partitions\n\n"); + for (i = 0, npart = 0, nsyms = 0; + VEC_iterate (tree, gimple_ssa_operands (cfun)->mpt_table, i, mpt); + i++) { - op = V_MUST_DEF_RESULT (old_ops->v_must_def_ops, j); - append_vuse (op); + if (mpt) + { + bitmap syms = MPT_SYMBOLS (mpt); + unsigned long n = bitmap_count_bits (syms); + + fprintf (file, "#%u: ", i); + print_generic_expr (file, mpt, 0); + fprintf (file, ": %lu elements: ", n); + dump_decl_set (file, syms); + npart++; + nsyms += n; + } } - /* Now set the vuses for this new stmt. */ - ann->operands.vuse_ops = finalize_ssa_vuses (&(tmp.vuse_ops)); + fprintf (file, "\n%u memory partitions holding %lu symbols\n", npart, nsyms); } -#include "gt-tree-ssa-operands.h" + +/* Dump memory partition information to stderr. */ + +void +debug_memory_partitions (void) +{ + dump_memory_partitions (stderr); +}