2004-05-13 08:41:07 +02:00
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/* SSA Dominator optimizations for trees
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Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
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Contributed by Diego Novillo <dnovillo@redhat.com>
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GCC is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING. If not, write to
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the Free Software Foundation, 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "flags.h"
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#include "rtl.h"
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#include "tm_p.h"
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#include "ggc.h"
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#include "basic-block.h"
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#include "output.h"
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#include "errors.h"
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#include "expr.h"
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#include "function.h"
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#include "diagnostic.h"
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#include "timevar.h"
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#include "tree-dump.h"
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#include "tree-flow.h"
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#include "domwalk.h"
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#include "real.h"
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#include "tree-pass.h"
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#include "langhooks.h"
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/* This file implements optimizations on the dominator tree. */
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/* Hash table with expressions made available during the renaming process.
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When an assignment of the form X_i = EXPR is found, the statement is
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stored in this table. If the same expression EXPR is later found on the
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RHS of another statement, it is replaced with X_i (thus performing
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global redundancy elimination). Similarly as we pass through conditionals
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we record the conditional itself as having either a true or false value
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in this table. */
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static htab_t avail_exprs;
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/* Structure for entries in the expression hash table.
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This requires more memory for the hash table entries, but allows us
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to avoid creating silly tree nodes and annotations for conditionals,
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eliminates 2 global hash tables and two block local varrays.
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It also allows us to reduce the number of hash table lookups we
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have to perform in lookup_avail_expr and finally it allows us to
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significantly reduce the number of calls into the hashing routine
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itself. */
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struct expr_hash_elt
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{
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/* The value (lhs) of this expression. */
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tree lhs;
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/* The expression (rhs) we want to record. */
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tree rhs;
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/* The annotation if this element corresponds to a statement. */
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stmt_ann_t ann;
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/* The hash value for RHS/ann. */
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hashval_t hash;
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};
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/* Table of constant values and copies indexed by SSA name. When the
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renaming pass finds an assignment of a constant (X_i = C) or a copy
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assignment from another SSA variable (X_i = Y_j), it creates a mapping
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between X_i and the RHS in this table. This mapping is used later on,
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when renaming uses of X_i. If an assignment to X_i is found in this
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table, instead of using X_i, we use the RHS of the statement stored in
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this table (thus performing very simplistic copy and constant
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propagation). */
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static varray_type const_and_copies;
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/* Bitmap of SSA_NAMEs known to have a nonzero value, even if we do not
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know their exact value. */
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static bitmap nonzero_vars;
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/* Track whether or not we have changed the control flow graph. */
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static bool cfg_altered;
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/* Statistics for dominator optimizations. */
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struct opt_stats_d
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{
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long num_stmts;
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long num_exprs_considered;
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long num_re;
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};
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/* Value range propagation record. Each time we encounter a conditional
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of the form SSA_NAME COND CONST we create a new vrp_element to record
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how the condition affects the possible values SSA_NAME may have.
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Each record contains the condition tested (COND), and the the range of
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values the variable may legitimately have if COND is true. Note the
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range of values may be a smaller range than COND specifies if we have
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recorded other ranges for this variable. Each record also contains the
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block in which the range was recorded for invalidation purposes.
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Note that the current known range is computed lazily. This allows us
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to avoid the overhead of computing ranges which are never queried.
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When we encounter a conditional, we look for records which constrain
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the SSA_NAME used in the condition. In some cases those records allow
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us to determine the condition's result at compile time. In other cases
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they may allow us to simplify the condition.
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We also use value ranges to do things like transform signed div/mod
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operations into unsigned div/mod or to simplify ABS_EXPRs.
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Simple experiments have shown these optimizations to not be all that
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useful on switch statements (much to my surprise). So switch statement
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optimizations are not performed.
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Note carefully we do not propagate information through each statement
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in the block. ie, if we know variable X has a value defined of
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[0, 25] and we encounter Y = X + 1, we do not track a value range
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for Y (which would be [1, 26] if we cared). Similarly we do not
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constrain values as we encounter narrowing typecasts, etc. */
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struct vrp_element
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{
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/* The highest and lowest values the variable in COND may contain when
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COND is true. Note this may not necessarily be the same values
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tested by COND if the same variable was used in earlier conditionals.
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Note this is computed lazily and thus can be NULL indicating that
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the values have not been computed yet. */
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tree low;
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tree high;
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/* The actual conditional we recorded. This is needed since we compute
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ranges lazily. */
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tree cond;
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/* The basic block where this record was created. We use this to determine
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when to remove records. */
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basic_block bb;
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};
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static struct opt_stats_d opt_stats;
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/* This virtual array holds pairs of edges which describe a scheduled
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edge redirection from jump threading.
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The first entry in each pair is the edge we are going to redirect.
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The second entry in each pair is the edge leading to our final
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destination block. By providing this as an edge rather than the
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final target block itself we can correctly handle redirections
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when the target block had PHIs which required edge insertions/splitting
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to remove the PHIs. */
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static GTY(()) varray_type redirection_edges;
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/* A virtual array holding value range records for the variable identified
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by the index, SSA_VERSION. */
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static varray_type vrp_data;
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/* Datastructure for block local data used during the dominator walk.
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We maintain a stack of these as we recursively walk down the
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dominator tree. */
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struct dom_walk_block_data
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{
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/* Array of all the expressions entered into the global expression
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hash table by this block. During finalization we use this array to
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know what expressions to remove from the global expression hash
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table. */
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varray_type avail_exprs;
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/* Array of dest, src pairs that need to be restored during finalization
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into the global const/copies table during finalization. */
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varray_type const_and_copies;
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/* Similarly for the nonzero state of variables that needs to be
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restored during finalization. */
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varray_type nonzero_vars;
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/* Array of statements we need to rescan during finalization for newly
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exposed variables. */
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varray_type stmts_to_rescan;
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/* Array of variables which have their values constrained by operations
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in this basic block. We use this during finalization to know
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which variables need their VRP data updated. */
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varray_type vrp_variables;
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/* Array of tree pairs used to restore the global currdefs to its
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original state after completing optimization of a block and its
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dominator children. */
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varray_type block_defs;
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};
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struct eq_expr_value
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{
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tree src;
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tree dst;
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};
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/* Local functions. */
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static void optimize_stmt (struct dom_walk_data *,
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basic_block bb,
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block_stmt_iterator);
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static inline tree get_value_for (tree, varray_type table);
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static inline void set_value_for (tree, tree, varray_type table);
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static tree lookup_avail_expr (tree, varray_type *, bool);
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static struct eq_expr_value get_eq_expr_value (tree, int, varray_type *,
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basic_block, varray_type *);
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static hashval_t avail_expr_hash (const void *);
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static int avail_expr_eq (const void *, const void *);
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static void htab_statistics (FILE *, htab_t);
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static void record_cond (tree, tree, varray_type *);
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static void record_const_or_copy (tree, tree, varray_type *);
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static void record_equality (tree, tree, varray_type *);
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static tree update_rhs_and_lookup_avail_expr (tree, tree, varray_type *,
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stmt_ann_t, bool);
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static tree simplify_rhs_and_lookup_avail_expr (struct dom_walk_data *,
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tree, stmt_ann_t, int);
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static tree simplify_cond_and_lookup_avail_expr (tree, varray_type *,
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stmt_ann_t, int);
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static tree simplify_switch_and_lookup_avail_expr (tree, varray_type *,
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stmt_ann_t, int);
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static tree find_equivalent_equality_comparison (tree);
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static void record_range (tree, basic_block, varray_type *);
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static bool extract_range_from_cond (tree, tree *, tree *, int *);
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static void record_equivalences_from_phis (struct dom_walk_data *, basic_block);
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static void record_equivalences_from_incoming_edge (struct dom_walk_data *,
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basic_block);
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static bool eliminate_redundant_computations (struct dom_walk_data *,
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tree, stmt_ann_t);
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static void record_equivalences_from_stmt (tree, varray_type *, varray_type *,
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int, stmt_ann_t);
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static void thread_across_edge (struct dom_walk_data *, edge);
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static void dom_opt_finalize_block (struct dom_walk_data *, basic_block);
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static void dom_opt_initialize_block_local_data (struct dom_walk_data *,
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basic_block, bool);
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static void dom_opt_initialize_block (struct dom_walk_data *, basic_block);
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static void cprop_into_phis (struct dom_walk_data *, basic_block);
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static void remove_local_expressions_from_table (varray_type locals,
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unsigned limit,
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htab_t table);
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static void restore_vars_to_original_value (varray_type locals,
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unsigned limit,
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varray_type table);
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static void restore_currdefs_to_original_value (varray_type locals,
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unsigned limit);
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static void register_definitions_for_stmt (stmt_ann_t, varray_type *);
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static void redirect_edges_and_update_ssa_graph (varray_type);
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/* Local version of fold that doesn't introduce cruft. */
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static tree
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local_fold (tree t)
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{
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t = fold (t);
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/* Strip away useless type conversions. Both the NON_LVALUE_EXPR that
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may have been added by fold, and "useless" type conversions that might
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now be apparent due to propagation. */
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STRIP_MAIN_TYPE_NOPS (t);
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STRIP_USELESS_TYPE_CONVERSION (t);
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return t;
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}
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/* Return the value associated with variable VAR in TABLE. */
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static inline tree
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get_value_for (tree var, varray_type table)
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{
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return VARRAY_TREE (table, SSA_NAME_VERSION (var));
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}
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/* Associate VALUE to variable VAR in TABLE. */
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static inline void
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set_value_for (tree var, tree value, varray_type table)
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{
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VARRAY_TREE (table, SSA_NAME_VERSION (var)) = value;
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}
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/* REDIRECTION_EDGES contains edge pairs where we want to revector the
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destination of the first edge to the destination of the second edge.
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These redirections may significantly change the SSA graph since we
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allow redirection through blocks with PHI nodes and blocks with
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real instructions in some cases.
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This routine will perform the requested redirections and incrementally
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update the SSA graph.
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Note in some cases requested redirections may be ignored as they can
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not be safely implemented. */
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static void
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redirect_edges_and_update_ssa_graph (varray_type redirection_edges)
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{
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2004-05-15 08:21:34 +02:00
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basic_block tgt, bb;
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tree phi;
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2004-05-13 08:41:07 +02:00
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unsigned int i;
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size_t old_num_referenced_vars = num_referenced_vars;
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2004-05-15 08:21:34 +02:00
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bitmap virtuals_to_rename = BITMAP_XMALLOC ();
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2004-05-13 08:41:07 +02:00
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/* First note any variables which we are going to have to take
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2004-05-15 08:21:34 +02:00
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out of SSA form as well as any virtuals which need updating. */
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2004-05-13 08:41:07 +02:00
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for (i = 0; i < VARRAY_ACTIVE_SIZE (redirection_edges); i += 2)
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{
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block_stmt_iterator bsi;
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edge e;
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basic_block tgt;
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tree phi;
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e = VARRAY_EDGE (redirection_edges, i);
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tgt = VARRAY_EDGE (redirection_edges, i + 1)->dest;
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/* All variables referenced in PHI nodes we bypass must be
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renamed. */
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tree.h (PHI_CHAIN): New.
* tree.h (PHI_CHAIN): New.
* (tree-cfg.c, tree-dfa.c, tree-flow-inline.h, tree-into-ssa.c,
tree-outof-ssa.c, tree-phinodes.c, tree-pretty-print.c,
tree-ssa-alias.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-dse.c,
tree-ssa-live.c, tree-ssa-loop.c, tree-ssa-phiopt.c, tree-ssa-pre.c,
tree-ssa.c, tree-tailcall.c): Use PHI_CHAIN instead of TREE_CHAIN
when traversing a list of PHI_NODEs.
From-SVN: r83273
2004-06-17 01:03:34 +02:00
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for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
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2004-05-13 08:41:07 +02:00
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{
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tree result = SSA_NAME_VAR (PHI_RESULT (phi));
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2004-05-15 08:21:34 +02:00
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if (is_gimple_reg (PHI_RESULT (phi)))
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bitmap_set_bit (vars_to_rename, var_ann (result)->uid);
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else
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bitmap_set_bit (virtuals_to_rename, var_ann (result)->uid);
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2004-05-13 08:41:07 +02:00
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}
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|
/* Any variables set by statements at the start of the block we
|
|
|
|
are bypassing must also be taken our of SSA form. */
|
|
|
|
for (bsi = bsi_start (e->dest); ! bsi_end_p (bsi); bsi_next (&bsi))
|
|
|
|
{
|
|
|
|
unsigned int j;
|
|
|
|
def_optype defs;
|
2004-06-10 23:41:08 +02:00
|
|
|
v_may_def_optype v_may_defs;
|
|
|
|
v_must_def_optype v_must_defs;
|
2004-05-13 08:41:07 +02:00
|
|
|
tree stmt = bsi_stmt (bsi);
|
|
|
|
stmt_ann_t ann = stmt_ann (stmt);
|
|
|
|
|
|
|
|
if (TREE_CODE (stmt) == COND_EXPR)
|
|
|
|
break;
|
|
|
|
|
|
|
|
get_stmt_operands (stmt);
|
|
|
|
|
|
|
|
defs = DEF_OPS (ann);
|
|
|
|
for (j = 0; j < NUM_DEFS (defs); j++)
|
|
|
|
{
|
|
|
|
tree op = SSA_NAME_VAR (DEF_OP (defs, j));
|
|
|
|
bitmap_set_bit (vars_to_rename, var_ann (op)->uid);
|
|
|
|
}
|
|
|
|
|
2004-06-10 23:41:08 +02:00
|
|
|
v_may_defs = STMT_V_MAY_DEF_OPS (stmt);
|
|
|
|
for (j = 0; j < NUM_V_MAY_DEFS (v_may_defs); j++)
|
2004-05-13 08:41:07 +02:00
|
|
|
{
|
2004-06-10 23:41:08 +02:00
|
|
|
tree op = V_MAY_DEF_RESULT (v_may_defs, j);
|
|
|
|
bitmap_set_bit (vars_to_rename, var_ann (op)->uid);
|
|
|
|
}
|
|
|
|
|
|
|
|
v_must_defs = STMT_V_MUST_DEF_OPS (stmt);
|
|
|
|
for (j = 0; j < NUM_V_MUST_DEFS (v_must_defs); j++)
|
|
|
|
{
|
|
|
|
tree op = V_MUST_DEF_OP (v_must_defs, j);
|
|
|
|
bitmap_set_bit (vars_to_rename, var_ann (op)->uid);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Finally, any variables in PHI nodes at our final destination
|
|
|
|
must also be taken our of SSA form. */
|
tree.h (PHI_CHAIN): New.
* tree.h (PHI_CHAIN): New.
* (tree-cfg.c, tree-dfa.c, tree-flow-inline.h, tree-into-ssa.c,
tree-outof-ssa.c, tree-phinodes.c, tree-pretty-print.c,
tree-ssa-alias.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-dse.c,
tree-ssa-live.c, tree-ssa-loop.c, tree-ssa-phiopt.c, tree-ssa-pre.c,
tree-ssa.c, tree-tailcall.c): Use PHI_CHAIN instead of TREE_CHAIN
when traversing a list of PHI_NODEs.
From-SVN: r83273
2004-06-17 01:03:34 +02:00
|
|
|
for (phi = phi_nodes (tgt); phi; phi = PHI_CHAIN (phi))
|
2004-05-13 08:41:07 +02:00
|
|
|
{
|
|
|
|
tree result = SSA_NAME_VAR (PHI_RESULT (phi));
|
|
|
|
|
2004-05-15 08:21:34 +02:00
|
|
|
if (is_gimple_reg (PHI_RESULT (phi)))
|
|
|
|
bitmap_set_bit (vars_to_rename, var_ann (result)->uid);
|
|
|
|
else
|
|
|
|
bitmap_set_bit (virtuals_to_rename, var_ann (result)->uid);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Take those selected variables out of SSA form. This must be
|
|
|
|
done before we start redirecting edges. */
|
|
|
|
if (bitmap_first_set_bit (vars_to_rename) >= 0)
|
|
|
|
rewrite_vars_out_of_ssa (vars_to_rename);
|
|
|
|
|
|
|
|
/* The out of SSA translation above may split the edge from
|
|
|
|
E->src to E->dest. This could potentially cause us to lose
|
|
|
|
an assignment leading to invalid warnings about uninitialized
|
|
|
|
variables or incorrect code.
|
|
|
|
|
|
|
|
Luckily, we can detect this by looking at the last statement
|
|
|
|
in E->dest. If it is not a COND_EXPR or SWITCH_EXPR, then
|
|
|
|
the edge was split and instead of E, we want E->dest->succ. */
|
|
|
|
for (i = 0; i < VARRAY_ACTIVE_SIZE (redirection_edges); i += 2)
|
|
|
|
{
|
|
|
|
edge e = VARRAY_EDGE (redirection_edges, i);
|
|
|
|
tree last = last_stmt (e->dest);
|
|
|
|
|
|
|
|
if (last
|
|
|
|
&& TREE_CODE (last) != COND_EXPR
|
|
|
|
&& TREE_CODE (last) != SWITCH_EXPR)
|
|
|
|
{
|
|
|
|
e = e->dest->succ;
|
|
|
|
|
|
|
|
#ifdef ENABLE_CHECKING
|
|
|
|
/* There should only be a single successor if the
|
|
|
|
original edge was split. */
|
|
|
|
if (e->succ_next)
|
|
|
|
abort ();
|
|
|
|
#endif
|
|
|
|
/* Replace the edge in REDIRECTION_EDGES for the
|
|
|
|
loop below. */
|
|
|
|
VARRAY_EDGE (redirection_edges, i) = e;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we created any new variables as part of the out-of-ssa
|
|
|
|
translation, then any jump threads must be invalidated if they
|
|
|
|
bypass a block in which we skipped instructions.
|
|
|
|
|
|
|
|
This is necessary as instructions which appeared to be NOPS
|
|
|
|
may be necessary after the out-of-ssa translation. */
|
|
|
|
if (num_referenced_vars != old_num_referenced_vars)
|
|
|
|
{
|
|
|
|
for (i = 0; i < VARRAY_ACTIVE_SIZE (redirection_edges); i += 2)
|
|
|
|
{
|
|
|
|
block_stmt_iterator bsi;
|
|
|
|
edge e;
|
|
|
|
|
|
|
|
e = VARRAY_EDGE (redirection_edges, i);
|
|
|
|
for (bsi = bsi_start (e->dest); ! bsi_end_p (bsi); bsi_next (&bsi))
|
|
|
|
{
|
|
|
|
tree stmt = bsi_stmt (bsi);
|
|
|
|
|
|
|
|
if (IS_EMPTY_STMT (stmt)
|
|
|
|
|| TREE_CODE (stmt) == LABEL_EXPR)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
if (TREE_CODE (stmt) == COND_EXPR)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* Invalidate the jump thread. */
|
|
|
|
VARRAY_EDGE (redirection_edges, i) = NULL;
|
|
|
|
VARRAY_EDGE (redirection_edges, i + 1) = NULL;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Now redirect the edges. */
|
|
|
|
for (i = 0; i < VARRAY_ACTIVE_SIZE (redirection_edges); i += 2)
|
|
|
|
{
|
|
|
|
basic_block src;
|
|
|
|
edge e;
|
|
|
|
|
|
|
|
e = VARRAY_EDGE (redirection_edges, i);
|
|
|
|
if (!e)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
tgt = VARRAY_EDGE (redirection_edges, i + 1)->dest;
|
|
|
|
|
|
|
|
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
|
|
fprintf (dump_file, " Threaded jump %d --> %d to %d\n",
|
|
|
|
e->src->index, e->dest->index, tgt->index);
|
|
|
|
|
|
|
|
src = e->src;
|
|
|
|
|
|
|
|
e = redirect_edge_and_branch (e, tgt);
|
|
|
|
PENDING_STMT (e) = NULL_TREE;
|
|
|
|
|
|
|
|
/* Updating the dominance information would be nontrivial. */
|
|
|
|
free_dominance_info (CDI_DOMINATORS);
|
|
|
|
|
|
|
|
if ((dump_file && (dump_flags & TDF_DETAILS))
|
|
|
|
&& e->src != src)
|
|
|
|
fprintf (dump_file, " basic block %d created\n",
|
|
|
|
e->src->index);
|
|
|
|
|
|
|
|
cfg_altered = true;
|
|
|
|
}
|
|
|
|
|
|
|
|
VARRAY_CLEAR (redirection_edges);
|
|
|
|
|
|
|
|
for (i = old_num_referenced_vars; i < num_referenced_vars; i++)
|
|
|
|
{
|
|
|
|
bitmap_set_bit (vars_to_rename, i);
|
|
|
|
var_ann (referenced_var (i))->out_of_ssa_tag = 0;
|
|
|
|
}
|
2004-05-15 08:21:34 +02:00
|
|
|
|
|
|
|
bitmap_a_or_b (vars_to_rename, vars_to_rename, virtuals_to_rename);
|
|
|
|
|
|
|
|
/* We must remove any PHIs for virtual variables that we are going to
|
|
|
|
re-rename. Hopefully we'll be able to simply update these incrementally
|
|
|
|
soon. */
|
|
|
|
FOR_EACH_BB (bb)
|
|
|
|
{
|
|
|
|
tree next;
|
|
|
|
|
|
|
|
for (phi = phi_nodes (bb); phi; phi = next)
|
|
|
|
{
|
|
|
|
tree result = PHI_RESULT (phi);
|
|
|
|
|
tree.h (PHI_CHAIN): New.
* tree.h (PHI_CHAIN): New.
* (tree-cfg.c, tree-dfa.c, tree-flow-inline.h, tree-into-ssa.c,
tree-outof-ssa.c, tree-phinodes.c, tree-pretty-print.c,
tree-ssa-alias.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-dse.c,
tree-ssa-live.c, tree-ssa-loop.c, tree-ssa-phiopt.c, tree-ssa-pre.c,
tree-ssa.c, tree-tailcall.c): Use PHI_CHAIN instead of TREE_CHAIN
when traversing a list of PHI_NODEs.
From-SVN: r83273
2004-06-17 01:03:34 +02:00
|
|
|
next = PHI_CHAIN (phi);
|
2004-05-15 08:21:34 +02:00
|
|
|
|
|
|
|
if (bitmap_bit_p (virtuals_to_rename,
|
|
|
|
var_ann (SSA_NAME_VAR (result))->uid))
|
|
|
|
remove_phi_node (phi, NULL, bb);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
BITMAP_XFREE (virtuals_to_rename);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Jump threading, redundancy elimination and const/copy propagation.
|
|
|
|
|
|
|
|
Optimize function FNDECL based on a walk through the dominator tree.
|
|
|
|
|
|
|
|
This pass may expose new symbols that need to be renamed into SSA. For
|
|
|
|
every new symbol exposed, its corresponding bit will be set in
|
|
|
|
VARS_TO_RENAME.
|
|
|
|
|
|
|
|
PHASE indicates which dump file from the DUMP_FILES array to use when
|
|
|
|
dumping debugging information. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
tree_ssa_dominator_optimize (void)
|
|
|
|
{
|
|
|
|
basic_block bb;
|
|
|
|
struct dom_walk_data walk_data;
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
for (i = 0; i < num_referenced_vars; i++)
|
|
|
|
var_ann (referenced_var (i))->current_def = NULL;
|
|
|
|
|
|
|
|
/* Mark loop edges so we avoid threading across loop boundaries.
|
|
|
|
This may result in transforming natural loop into irreducible
|
|
|
|
region. */
|
|
|
|
mark_dfs_back_edges ();
|
|
|
|
|
|
|
|
/* Create our hash tables. */
|
|
|
|
avail_exprs = htab_create (1024, avail_expr_hash, avail_expr_eq, free);
|
2004-06-11 00:37:05 +02:00
|
|
|
VARRAY_TREE_INIT (const_and_copies, num_ssa_names, "const_and_copies");
|
2004-05-13 08:41:07 +02:00
|
|
|
nonzero_vars = BITMAP_XMALLOC ();
|
|
|
|
VARRAY_EDGE_INIT (redirection_edges, 20, "redirection_edges");
|
2004-06-11 00:37:05 +02:00
|
|
|
VARRAY_GENERIC_PTR_INIT (vrp_data, num_ssa_names, "vrp_data");
|
2004-05-13 08:41:07 +02:00
|
|
|
|
|
|
|
/* Setup callbacks for the generic dominator tree walker. */
|
|
|
|
walk_data.walk_stmts_backward = false;
|
|
|
|
walk_data.dom_direction = CDI_DOMINATORS;
|
|
|
|
walk_data.initialize_block_local_data = dom_opt_initialize_block_local_data;
|
|
|
|
walk_data.before_dom_children_before_stmts = dom_opt_initialize_block;
|
|
|
|
walk_data.before_dom_children_walk_stmts = optimize_stmt;
|
|
|
|
walk_data.before_dom_children_after_stmts = cprop_into_phis;
|
|
|
|
walk_data.after_dom_children_before_stmts = NULL;
|
|
|
|
walk_data.after_dom_children_walk_stmts = NULL;
|
|
|
|
walk_data.after_dom_children_after_stmts = dom_opt_finalize_block;
|
|
|
|
/* Right now we only attach a dummy COND_EXPR to the global data pointer.
|
|
|
|
When we attach more stuff we'll need to fill this out with a real
|
|
|
|
structure. */
|
|
|
|
walk_data.global_data = NULL;
|
|
|
|
walk_data.block_local_data_size = sizeof (struct dom_walk_block_data);
|
|
|
|
|
|
|
|
/* Now initialize the dominator walker. */
|
|
|
|
init_walk_dominator_tree (&walk_data);
|
|
|
|
|
|
|
|
/* Reset block_forwardable in each block's annotation. We use that
|
|
|
|
attribute when threading through COND_EXPRs. */
|
|
|
|
FOR_EACH_BB (bb)
|
|
|
|
bb_ann (bb)->forwardable = 1;
|
|
|
|
|
|
|
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
|
|
|
|
|
|
/* If we prove certain blocks are unreachable, then we want to
|
|
|
|
repeat the dominator optimization process as PHI nodes may
|
|
|
|
have turned into copies which allows better propagation of
|
|
|
|
values. So we repeat until we do not identify any new unreachable
|
|
|
|
blocks. */
|
|
|
|
do
|
|
|
|
{
|
|
|
|
/* Optimize the dominator tree. */
|
|
|
|
cfg_altered = false;
|
|
|
|
|
|
|
|
/* Recursively walk the dominator tree optimizing statements. */
|
|
|
|
walk_dominator_tree (&walk_data, ENTRY_BLOCK_PTR);
|
|
|
|
|
|
|
|
/* Wipe the hash tables. */
|
|
|
|
|
|
|
|
if (VARRAY_ACTIVE_SIZE (redirection_edges) > 0)
|
|
|
|
redirect_edges_and_update_ssa_graph (redirection_edges);
|
|
|
|
|
|
|
|
/* We may have made some basic blocks unreachable, remove them. */
|
|
|
|
cfg_altered |= delete_unreachable_blocks ();
|
|
|
|
|
|
|
|
/* If the CFG was altered, then recompute the dominator tree. This
|
|
|
|
is not strictly needed if we only removed unreachable blocks, but
|
|
|
|
may produce better results. If we threaded jumps, then rebuilding
|
|
|
|
the dominator tree is strictly necessary. */
|
|
|
|
if (cfg_altered)
|
|
|
|
{
|
|
|
|
cleanup_tree_cfg ();
|
|
|
|
calculate_dominance_info (CDI_DOMINATORS);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we are going to iterate (CFG_ALTERED is true), then we must
|
|
|
|
perform any queued renaming before the next iteration. */
|
|
|
|
if (cfg_altered
|
|
|
|
&& bitmap_first_set_bit (vars_to_rename) >= 0)
|
|
|
|
{
|
|
|
|
rewrite_into_ssa ();
|
|
|
|
bitmap_clear (vars_to_rename);
|
|
|
|
|
|
|
|
/* The into SSA translation may have created new SSA_NAMES whic
|
|
|
|
affect the size of CONST_AND_COPIES and VRP_DATA. */
|
2004-06-11 00:37:05 +02:00
|
|
|
VARRAY_GROW (const_and_copies, num_ssa_names);
|
|
|
|
VARRAY_GROW (vrp_data, num_ssa_names);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Reinitialize the various tables. */
|
|
|
|
bitmap_clear (nonzero_vars);
|
|
|
|
htab_empty (avail_exprs);
|
|
|
|
VARRAY_CLEAR (const_and_copies);
|
|
|
|
VARRAY_CLEAR (vrp_data);
|
|
|
|
|
|
|
|
for (i = 0; i < num_referenced_vars; i++)
|
|
|
|
var_ann (referenced_var (i))->current_def = NULL;
|
|
|
|
}
|
|
|
|
while (cfg_altered);
|
|
|
|
|
|
|
|
/* Remove any unreachable blocks left behind and linearize the CFG. */
|
|
|
|
cleanup_tree_cfg ();
|
|
|
|
|
|
|
|
/* Debugging dumps. */
|
|
|
|
if (dump_file && (dump_flags & TDF_STATS))
|
|
|
|
dump_dominator_optimization_stats (dump_file);
|
|
|
|
|
|
|
|
/* We emptyed the hash table earlier, now delete it completely. */
|
|
|
|
htab_delete (avail_exprs);
|
|
|
|
|
c-common.c, [...]: Fix comment typos.
* c-common.c, calls.c, cfgcleanup.c, cgraph.c, cgraphunit.c,
ddg.c, ddg.h, df.c, df.h, except.c, expr.c, flags.h,
fold-const.c, gcc.c, gimplify.c, haifa-sched.c,
modulo-sched.c, tree-inline.c, tree-into-ssa.c, tree-nested.c,
tree-nrv.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-live.c,
tree-ssa-loop.c, tree-ssa-pre.c, tree-tailcall.c, tree.h: Fix
comment typos. Follow spelling conventions.
From-SVN: r82439
2004-05-30 09:12:58 +02:00
|
|
|
/* It is not necessary to clear CURRDEFS, REDIRECTION_EDGES, VRP_DATA,
|
2004-05-13 08:41:07 +02:00
|
|
|
CONST_AND_COPIES, and NONZERO_VARS as they all get cleared at the bottom
|
|
|
|
of the do-while loop above. */
|
|
|
|
|
|
|
|
/* And finalize the dominator walker. */
|
|
|
|
fini_walk_dominator_tree (&walk_data);
|
2004-05-13 17:21:53 +02:00
|
|
|
|
|
|
|
/* Free nonzero_vars. */
|
|
|
|
BITMAP_XFREE (nonzero_vars);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
static bool
|
|
|
|
gate_dominator (void)
|
|
|
|
{
|
|
|
|
return flag_tree_dom != 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct tree_opt_pass pass_dominator =
|
|
|
|
{
|
|
|
|
"dom", /* name */
|
|
|
|
gate_dominator, /* gate */
|
|
|
|
tree_ssa_dominator_optimize, /* execute */
|
|
|
|
NULL, /* sub */
|
|
|
|
NULL, /* next */
|
|
|
|
0, /* static_pass_number */
|
|
|
|
TV_TREE_SSA_DOMINATOR_OPTS, /* tv_id */
|
|
|
|
PROP_cfg | PROP_ssa, /* properties_required */
|
|
|
|
0, /* properties_provided */
|
|
|
|
0, /* properties_destroyed */
|
|
|
|
0, /* todo_flags_start */
|
|
|
|
TODO_dump_func | TODO_rename_vars
|
|
|
|
| TODO_verify_ssa /* todo_flags_finish */
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
/* We are exiting BB, see if the target block begins with a conditional
|
|
|
|
jump which has a known value when reached via BB. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
thread_across_edge (struct dom_walk_data *walk_data, edge e)
|
|
|
|
{
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
block_stmt_iterator bsi;
|
|
|
|
tree stmt = NULL;
|
|
|
|
tree phi;
|
|
|
|
|
|
|
|
/* Each PHI creates a temporary equivalence, record them. */
|
tree.h (PHI_CHAIN): New.
* tree.h (PHI_CHAIN): New.
* (tree-cfg.c, tree-dfa.c, tree-flow-inline.h, tree-into-ssa.c,
tree-outof-ssa.c, tree-phinodes.c, tree-pretty-print.c,
tree-ssa-alias.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-dse.c,
tree-ssa-live.c, tree-ssa-loop.c, tree-ssa-phiopt.c, tree-ssa-pre.c,
tree-ssa.c, tree-tailcall.c): Use PHI_CHAIN instead of TREE_CHAIN
when traversing a list of PHI_NODEs.
From-SVN: r83273
2004-06-17 01:03:34 +02:00
|
|
|
for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi))
|
2004-05-13 08:41:07 +02:00
|
|
|
{
|
|
|
|
tree src = PHI_ARG_DEF (phi, phi_arg_from_edge (phi, e));
|
|
|
|
tree dst = PHI_RESULT (phi);
|
|
|
|
record_const_or_copy (dst, src, &bd->const_and_copies);
|
|
|
|
register_new_def (dst, &bd->block_defs);
|
|
|
|
}
|
|
|
|
|
|
|
|
for (bsi = bsi_start (e->dest); ! bsi_end_p (bsi); bsi_next (&bsi))
|
|
|
|
{
|
|
|
|
tree lhs, cached_lhs;
|
|
|
|
|
|
|
|
stmt = bsi_stmt (bsi);
|
|
|
|
|
|
|
|
/* Ignore empty statements and labels. */
|
|
|
|
if (IS_EMPTY_STMT (stmt) || TREE_CODE (stmt) == LABEL_EXPR)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/* If this is not a MODIFY_EXPR which sets an SSA_NAME to a new
|
|
|
|
value, then stop our search here. Ideally when we stop a
|
|
|
|
search we stop on a COND_EXPR or SWITCH_EXPR. */
|
|
|
|
if (TREE_CODE (stmt) != MODIFY_EXPR
|
|
|
|
|| TREE_CODE (TREE_OPERAND (stmt, 0)) != SSA_NAME)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* At this point we have a statement which assigns an RHS to an
|
|
|
|
SSA_VAR on the LHS. We want to prove that the RHS is already
|
|
|
|
available and that its value is held in the current definition
|
|
|
|
of the LHS -- meaning that this assignment is a NOP when
|
|
|
|
reached via edge E. */
|
|
|
|
if (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME)
|
|
|
|
cached_lhs = TREE_OPERAND (stmt, 1);
|
|
|
|
else
|
|
|
|
cached_lhs = lookup_avail_expr (stmt, NULL, false);
|
|
|
|
|
|
|
|
lhs = TREE_OPERAND (stmt, 0);
|
|
|
|
|
|
|
|
/* This can happen if we thread around to the start of a loop. */
|
|
|
|
if (lhs == cached_lhs)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* If we did not find RHS in the hash table, then try again after
|
|
|
|
temporarily const/copy propagating the operands. */
|
|
|
|
if (!cached_lhs)
|
|
|
|
{
|
|
|
|
/* Copy the operands. */
|
|
|
|
stmt_ann_t ann = stmt_ann (stmt);
|
|
|
|
use_optype uses = USE_OPS (ann);
|
|
|
|
vuse_optype vuses = VUSE_OPS (ann);
|
|
|
|
tree *uses_copy = xcalloc (NUM_USES (uses), sizeof (tree));
|
|
|
|
tree *vuses_copy = xcalloc (NUM_VUSES (vuses), sizeof (tree));
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
/* Make a copy of the uses into USES_COPY, then cprop into
|
|
|
|
the use operands. */
|
|
|
|
for (i = 0; i < NUM_USES (uses); i++)
|
|
|
|
{
|
|
|
|
tree tmp = NULL;
|
|
|
|
|
|
|
|
uses_copy[i] = USE_OP (uses, i);
|
|
|
|
if (TREE_CODE (USE_OP (uses, i)) == SSA_NAME)
|
|
|
|
tmp = get_value_for (USE_OP (uses, i), const_and_copies);
|
|
|
|
if (tmp)
|
|
|
|
*USE_OP_PTR (uses, i) = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Similarly for virtual uses. */
|
|
|
|
for (i = 0; i < NUM_VUSES (vuses); i++)
|
|
|
|
{
|
|
|
|
tree tmp = NULL;
|
|
|
|
|
|
|
|
vuses_copy[i] = VUSE_OP (vuses, i);
|
|
|
|
if (TREE_CODE (VUSE_OP (vuses, i)) == SSA_NAME)
|
|
|
|
tmp = get_value_for (VUSE_OP (vuses, i), const_and_copies);
|
|
|
|
if (tmp)
|
|
|
|
VUSE_OP (vuses, i) = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Try to lookup the new expression. */
|
|
|
|
cached_lhs = lookup_avail_expr (stmt, NULL, false);
|
|
|
|
|
|
|
|
/* Restore the statement's original uses/defs. */
|
|
|
|
for (i = 0; i < NUM_USES (uses); i++)
|
|
|
|
*USE_OP_PTR (uses, i) = uses_copy[i];
|
|
|
|
|
|
|
|
for (i = 0; i < NUM_VUSES (vuses); i++)
|
|
|
|
VUSE_OP (vuses, i) = vuses_copy[i];
|
|
|
|
|
|
|
|
free (uses_copy);
|
|
|
|
free (vuses_copy);
|
|
|
|
|
|
|
|
/* If we still did not find the expression in the hash table,
|
|
|
|
then we can not ignore this statement. */
|
|
|
|
if (! cached_lhs)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If the expression in the hash table was not assigned to an
|
|
|
|
SSA_NAME, then we can not ignore this statement. */
|
|
|
|
if (TREE_CODE (cached_lhs) != SSA_NAME)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* If we have different underlying variables, then we can not
|
|
|
|
ignore this statement. */
|
|
|
|
if (SSA_NAME_VAR (cached_lhs) != SSA_NAME_VAR (lhs))
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* If CACHED_LHS does not represent the current value of the undering
|
|
|
|
variable in CACHED_LHS/LHS, then we can not ignore this statement. */
|
|
|
|
if (var_ann (SSA_NAME_VAR (lhs))->current_def != cached_lhs)
|
|
|
|
break;
|
|
|
|
|
|
|
|
/* If we got here, then we can ignore this statement and continue
|
|
|
|
walking through the statements in the block looking for a threadable
|
|
|
|
COND_EXPR.
|
|
|
|
|
|
|
|
We want to record an equivalence lhs = cache_lhs so that if
|
|
|
|
the result of this statement is used later we can copy propagate
|
|
|
|
suitably. */
|
|
|
|
record_const_or_copy (lhs, cached_lhs, &bd->const_and_copies);
|
|
|
|
register_new_def (lhs, &bd->block_defs);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we stopped at a COND_EXPR or SWITCH_EXPR, then see if we know which
|
|
|
|
arm will be taken. */
|
|
|
|
if (stmt
|
|
|
|
&& (TREE_CODE (stmt) == COND_EXPR
|
|
|
|
|| TREE_CODE (stmt) == SWITCH_EXPR))
|
|
|
|
{
|
|
|
|
tree cond, cached_lhs;
|
|
|
|
edge e1;
|
|
|
|
|
|
|
|
/* Do not forward entry edges into the loop. In the case loop
|
|
|
|
has multiple entry edges we may end up in constructing irreducible
|
|
|
|
region.
|
|
|
|
??? We may consider forwarding the edges in the case all incoming
|
|
|
|
edges forward to the same destination block. */
|
|
|
|
if (!e->flags & EDGE_DFS_BACK)
|
|
|
|
{
|
|
|
|
for (e1 = e->dest->pred; e; e = e->pred_next)
|
|
|
|
if (e1->flags & EDGE_DFS_BACK)
|
|
|
|
break;
|
|
|
|
if (e1)
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Now temporarily cprop the operands and try to find the resulting
|
|
|
|
expression in the hash tables. */
|
|
|
|
if (TREE_CODE (stmt) == COND_EXPR)
|
|
|
|
cond = COND_EXPR_COND (stmt);
|
|
|
|
else
|
|
|
|
cond = SWITCH_COND (stmt);
|
|
|
|
|
|
|
|
if (TREE_CODE_CLASS (TREE_CODE (cond)) == '<')
|
|
|
|
{
|
|
|
|
tree dummy_cond, op0, op1;
|
|
|
|
enum tree_code cond_code;
|
|
|
|
|
|
|
|
op0 = TREE_OPERAND (cond, 0);
|
|
|
|
op1 = TREE_OPERAND (cond, 1);
|
|
|
|
cond_code = TREE_CODE (cond);
|
|
|
|
|
|
|
|
/* Get the current value of both operands. */
|
|
|
|
if (TREE_CODE (op0) == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree tmp = get_value_for (op0, const_and_copies);
|
|
|
|
if (tmp)
|
|
|
|
op0 = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (TREE_CODE (op1) == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree tmp = get_value_for (op1, const_and_copies);
|
|
|
|
if (tmp)
|
|
|
|
op1 = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Stuff the operator and operands into our dummy conditional
|
|
|
|
expression, creating the dummy conditional if necessary. */
|
|
|
|
dummy_cond = walk_data->global_data;
|
|
|
|
if (! dummy_cond)
|
|
|
|
{
|
|
|
|
dummy_cond = build (cond_code, boolean_type_node, op0, op1);
|
|
|
|
dummy_cond = build (COND_EXPR, void_type_node,
|
|
|
|
dummy_cond, NULL, NULL);
|
|
|
|
walk_data->global_data = dummy_cond;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
TREE_SET_CODE (TREE_OPERAND (dummy_cond, 0), cond_code);
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 0) = op0;
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 1) = op1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If the conditional folds to an invariant, then we are done,
|
|
|
|
otherwise look it up in the hash tables. */
|
|
|
|
cached_lhs = local_fold (COND_EXPR_COND (dummy_cond));
|
|
|
|
if (! is_gimple_min_invariant (cached_lhs))
|
|
|
|
cached_lhs = lookup_avail_expr (dummy_cond, NULL, false);
|
|
|
|
if (!cached_lhs || ! is_gimple_min_invariant (cached_lhs))
|
|
|
|
{
|
|
|
|
stmt_ann_t ann = get_stmt_ann (dummy_cond);
|
|
|
|
cached_lhs = simplify_cond_and_lookup_avail_expr (dummy_cond,
|
|
|
|
NULL,
|
|
|
|
ann,
|
|
|
|
false);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
/* We can have conditionals which just test the state of a
|
|
|
|
variable rather than use a relational operator. These are
|
|
|
|
simpler to handle. */
|
|
|
|
else if (TREE_CODE (cond) == SSA_NAME)
|
|
|
|
{
|
|
|
|
cached_lhs = cond;
|
|
|
|
cached_lhs = get_value_for (cached_lhs, const_and_copies);
|
|
|
|
if (cached_lhs && ! is_gimple_min_invariant (cached_lhs))
|
|
|
|
cached_lhs = 0;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
cached_lhs = lookup_avail_expr (stmt, NULL, false);
|
|
|
|
|
|
|
|
if (cached_lhs)
|
|
|
|
{
|
|
|
|
edge taken_edge = find_taken_edge (e->dest, cached_lhs);
|
|
|
|
basic_block dest = (taken_edge ? taken_edge->dest : NULL);
|
|
|
|
|
2004-06-16 15:39:49 +02:00
|
|
|
if (dest == e->dest)
|
2004-05-13 08:41:07 +02:00
|
|
|
return;
|
|
|
|
|
|
|
|
/* If we have a known destination for the conditional, then
|
|
|
|
we can perform this optimization, which saves at least one
|
|
|
|
conditional jump each time it applies since we get to
|
|
|
|
bypass the conditional at our original destination.
|
|
|
|
|
|
|
|
Note that we can either thread through a block with PHIs
|
|
|
|
or to a block with PHIs, but not both. At this time the
|
|
|
|
bookkeeping to keep the CFG & SSA up-to-date has proven
|
|
|
|
difficult. */
|
|
|
|
if (dest)
|
|
|
|
{
|
|
|
|
int saved_forwardable = bb_ann (e->src)->forwardable;
|
|
|
|
edge tmp_edge;
|
|
|
|
|
|
|
|
bb_ann (e->src)->forwardable = 0;
|
|
|
|
tmp_edge = tree_block_forwards_to (dest);
|
|
|
|
taken_edge = (tmp_edge ? tmp_edge : taken_edge);
|
|
|
|
bb_ann (e->src)->forwardable = saved_forwardable;
|
|
|
|
VARRAY_PUSH_EDGE (redirection_edges, e);
|
|
|
|
VARRAY_PUSH_EDGE (redirection_edges, taken_edge);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Initialize the local stacks.
|
|
|
|
|
|
|
|
AVAIL_EXPRS stores all the expressions made available in this block.
|
|
|
|
|
|
|
|
CONST_AND_COPIES stores var/value pairs to restore at the end of this
|
|
|
|
block.
|
|
|
|
|
|
|
|
NONZERO_VARS stores the vars which have a nonzero value made in this
|
|
|
|
block.
|
|
|
|
|
|
|
|
STMTS_TO_RESCAN is a list of statements we will rescan for operands.
|
|
|
|
|
|
|
|
VRP_VARIABLES is the list of variables which have had their values
|
|
|
|
constrained by an operation in this block.
|
|
|
|
|
|
|
|
These stacks are cleared in the finalization routine run for each
|
|
|
|
block. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
dom_opt_initialize_block_local_data (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
|
|
|
|
basic_block bb ATTRIBUTE_UNUSED,
|
|
|
|
bool recycled ATTRIBUTE_UNUSED)
|
|
|
|
{
|
|
|
|
#ifdef ENABLE_CHECKING
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= (struct dom_walk_block_data *)VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
|
|
|
|
/* We get cleared memory from the allocator, so if the memory is not
|
|
|
|
cleared, then we are re-using a previously allocated entry. In
|
|
|
|
that case, we can also re-use the underlying virtual arrays. Just
|
|
|
|
make sure we clear them before using them! */
|
|
|
|
if (recycled)
|
|
|
|
{
|
|
|
|
if (bd->avail_exprs && VARRAY_ACTIVE_SIZE (bd->avail_exprs) > 0)
|
|
|
|
abort ();
|
|
|
|
if (bd->const_and_copies && VARRAY_ACTIVE_SIZE (bd->const_and_copies) > 0)
|
|
|
|
abort ();
|
|
|
|
if (bd->nonzero_vars && VARRAY_ACTIVE_SIZE (bd->nonzero_vars) > 0)
|
|
|
|
abort ();
|
|
|
|
if (bd->stmts_to_rescan && VARRAY_ACTIVE_SIZE (bd->stmts_to_rescan) > 0)
|
|
|
|
abort ();
|
|
|
|
if (bd->vrp_variables && VARRAY_ACTIVE_SIZE (bd->vrp_variables) > 0)
|
|
|
|
abort ();
|
|
|
|
if (bd->block_defs && VARRAY_ACTIVE_SIZE (bd->block_defs) > 0)
|
|
|
|
abort ();
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Initialize local stacks for this optimizer and record equivalences
|
|
|
|
upon entry to BB. Equivalences can come from the edge traversed to
|
|
|
|
reach BB or they may come from PHI nodes at the start of BB. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
dom_opt_initialize_block (struct dom_walk_data *walk_data, basic_block bb)
|
|
|
|
{
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
|
|
fprintf (dump_file, "\n\nOptimizing block #%d\n\n", bb->index);
|
|
|
|
|
|
|
|
record_equivalences_from_incoming_edge (walk_data, bb);
|
|
|
|
|
|
|
|
/* PHI nodes can create equivalences too. */
|
|
|
|
record_equivalences_from_phis (walk_data, bb);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Given an expression EXPR (a relational expression or a statement),
|
|
|
|
initialize the hash table element pointed by by ELEMENT. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
initialize_hash_element (tree expr, tree lhs, struct expr_hash_elt *element)
|
|
|
|
{
|
|
|
|
/* Hash table elements may be based on conditional expressions or statements.
|
|
|
|
|
|
|
|
For the former case, we have no annotation and we want to hash the
|
|
|
|
conditional expression. In the latter case we have an annotation and
|
|
|
|
we want to record the expression the statement evaluates. */
|
|
|
|
if (TREE_CODE_CLASS (TREE_CODE (expr)) == '<'
|
|
|
|
|| TREE_CODE (expr) == TRUTH_NOT_EXPR)
|
|
|
|
{
|
|
|
|
element->ann = NULL;
|
|
|
|
element->rhs = expr;
|
|
|
|
}
|
|
|
|
else if (TREE_CODE (expr) == COND_EXPR)
|
|
|
|
{
|
|
|
|
element->ann = stmt_ann (expr);
|
|
|
|
element->rhs = COND_EXPR_COND (expr);
|
|
|
|
}
|
|
|
|
else if (TREE_CODE (expr) == SWITCH_EXPR)
|
|
|
|
{
|
|
|
|
element->ann = stmt_ann (expr);
|
|
|
|
element->rhs = SWITCH_COND (expr);
|
|
|
|
}
|
|
|
|
else if (TREE_CODE (expr) == RETURN_EXPR && TREE_OPERAND (expr, 0))
|
|
|
|
{
|
|
|
|
element->ann = stmt_ann (expr);
|
|
|
|
element->rhs = TREE_OPERAND (TREE_OPERAND (expr, 0), 1);
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
element->ann = stmt_ann (expr);
|
|
|
|
element->rhs = TREE_OPERAND (expr, 1);
|
|
|
|
}
|
|
|
|
|
|
|
|
element->lhs = lhs;
|
|
|
|
element->hash = avail_expr_hash (element);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Remove all the expressions in LOCALS from TABLE, stopping when there are
|
|
|
|
LIMIT entries left in LOCALs. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
remove_local_expressions_from_table (varray_type locals,
|
|
|
|
unsigned limit,
|
|
|
|
htab_t table)
|
|
|
|
{
|
|
|
|
if (! locals)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Remove all the expressions made available in this block. */
|
|
|
|
while (VARRAY_ACTIVE_SIZE (locals) > limit)
|
|
|
|
{
|
|
|
|
struct expr_hash_elt element;
|
|
|
|
tree expr = VARRAY_TOP_TREE (locals);
|
|
|
|
VARRAY_POP (locals);
|
|
|
|
|
|
|
|
initialize_hash_element (expr, NULL, &element);
|
|
|
|
htab_remove_elt_with_hash (table, &element, element.hash);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Use the SSA_NAMES in LOCALS to restore TABLE to its original
|
c-common.c, [...]: Fix comment typos.
* c-common.c, calls.c, cfgcleanup.c, cgraph.c, cgraphunit.c,
ddg.c, ddg.h, df.c, df.h, except.c, expr.c, flags.h,
fold-const.c, gcc.c, gimplify.c, haifa-sched.c,
modulo-sched.c, tree-inline.c, tree-into-ssa.c, tree-nested.c,
tree-nrv.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-live.c,
tree-ssa-loop.c, tree-ssa-pre.c, tree-tailcall.c, tree.h: Fix
comment typos. Follow spelling conventions.
From-SVN: r82439
2004-05-30 09:12:58 +02:00
|
|
|
state, stopping when there are LIMIT entries left in LOCALs. */
|
2004-05-13 08:41:07 +02:00
|
|
|
|
|
|
|
static void
|
|
|
|
restore_nonzero_vars_to_original_value (varray_type locals,
|
|
|
|
unsigned limit,
|
|
|
|
bitmap table)
|
|
|
|
{
|
|
|
|
if (!locals)
|
|
|
|
return;
|
|
|
|
|
|
|
|
while (VARRAY_ACTIVE_SIZE (locals) > limit)
|
|
|
|
{
|
|
|
|
tree name = VARRAY_TOP_TREE (locals);
|
|
|
|
VARRAY_POP (locals);
|
|
|
|
bitmap_clear_bit (table, SSA_NAME_VERSION (name));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Use the source/dest pairs in LOCALS to restore TABLE to its original
|
c-common.c, [...]: Fix comment typos.
* c-common.c, calls.c, cfgcleanup.c, cgraph.c, cgraphunit.c,
ddg.c, ddg.h, df.c, df.h, except.c, expr.c, flags.h,
fold-const.c, gcc.c, gimplify.c, haifa-sched.c,
modulo-sched.c, tree-inline.c, tree-into-ssa.c, tree-nested.c,
tree-nrv.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-live.c,
tree-ssa-loop.c, tree-ssa-pre.c, tree-tailcall.c, tree.h: Fix
comment typos. Follow spelling conventions.
From-SVN: r82439
2004-05-30 09:12:58 +02:00
|
|
|
state, stopping when there are LIMIT entries left in LOCALs. */
|
2004-05-13 08:41:07 +02:00
|
|
|
|
|
|
|
static void
|
|
|
|
restore_vars_to_original_value (varray_type locals,
|
|
|
|
unsigned limit,
|
|
|
|
varray_type table)
|
|
|
|
{
|
|
|
|
if (! locals)
|
|
|
|
return;
|
|
|
|
|
|
|
|
while (VARRAY_ACTIVE_SIZE (locals) > limit)
|
|
|
|
{
|
|
|
|
tree prev_value, dest;
|
|
|
|
|
|
|
|
prev_value = VARRAY_TOP_TREE (locals);
|
|
|
|
VARRAY_POP (locals);
|
|
|
|
dest = VARRAY_TOP_TREE (locals);
|
|
|
|
VARRAY_POP (locals);
|
|
|
|
|
|
|
|
set_value_for (dest, prev_value, table);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Similar to restore_vars_to_original_value, except that it restores
|
|
|
|
CURRDEFS to its original value. */
|
|
|
|
static void
|
|
|
|
restore_currdefs_to_original_value (varray_type locals, unsigned limit)
|
|
|
|
{
|
|
|
|
if (!locals)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Restore CURRDEFS to its original state. */
|
|
|
|
while (VARRAY_ACTIVE_SIZE (locals) > limit)
|
|
|
|
{
|
|
|
|
tree tmp = VARRAY_TOP_TREE (locals);
|
|
|
|
tree saved_def, var;
|
|
|
|
|
|
|
|
VARRAY_POP (locals);
|
|
|
|
|
|
|
|
/* If we recorded an SSA_NAME, then make the SSA_NAME the current
|
|
|
|
definition of its underlying variable. If we recorded anything
|
|
|
|
else, it must have been an _DECL node and its current reaching
|
|
|
|
definition must have been NULL. */
|
|
|
|
if (TREE_CODE (tmp) == SSA_NAME)
|
|
|
|
{
|
|
|
|
saved_def = tmp;
|
|
|
|
var = SSA_NAME_VAR (saved_def);
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
saved_def = NULL;
|
|
|
|
var = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
var_ann (var)->current_def = saved_def;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* We have finished processing the dominator children of BB, perform
|
|
|
|
any finalization actions in preparation for leaving this node in
|
|
|
|
the dominator tree. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
dom_opt_finalize_block (struct dom_walk_data *walk_data, basic_block bb)
|
|
|
|
{
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
tree last;
|
|
|
|
|
|
|
|
/* If we are at a leaf node in the dominator graph, see if we can thread
|
|
|
|
the edge from BB through its successor.
|
|
|
|
|
|
|
|
Do this before we remove entries from our equivalence tables. */
|
|
|
|
if (bb->succ
|
|
|
|
&& ! bb->succ->succ_next
|
|
|
|
&& (bb->succ->flags & EDGE_ABNORMAL) == 0
|
|
|
|
&& (get_immediate_dominator (CDI_DOMINATORS, bb->succ->dest) != bb
|
|
|
|
|| phi_nodes (bb->succ->dest)))
|
|
|
|
|
|
|
|
{
|
|
|
|
thread_across_edge (walk_data, bb->succ);
|
|
|
|
}
|
|
|
|
else if ((last = last_stmt (bb))
|
|
|
|
&& TREE_CODE (last) == COND_EXPR
|
|
|
|
&& (TREE_CODE_CLASS (TREE_CODE (COND_EXPR_COND (last))) == '<'
|
|
|
|
|| TREE_CODE (COND_EXPR_COND (last)) == SSA_NAME)
|
|
|
|
&& bb->succ
|
|
|
|
&& (bb->succ->flags & EDGE_ABNORMAL) == 0
|
|
|
|
&& bb->succ->succ_next
|
|
|
|
&& (bb->succ->succ_next->flags & EDGE_ABNORMAL) == 0
|
|
|
|
&& ! bb->succ->succ_next->succ_next)
|
|
|
|
{
|
|
|
|
edge true_edge, false_edge;
|
|
|
|
tree cond, inverted = NULL;
|
|
|
|
enum tree_code cond_code;
|
|
|
|
|
|
|
|
extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
|
|
|
|
|
|
|
|
cond = COND_EXPR_COND (last);
|
|
|
|
cond_code = TREE_CODE (cond);
|
|
|
|
|
|
|
|
if (TREE_CODE_CLASS (cond_code) == '<')
|
|
|
|
inverted = invert_truthvalue (cond);
|
|
|
|
|
|
|
|
/* If the THEN arm is the end of a dominator tree or has PHI nodes,
|
|
|
|
then try to thread through its edge. */
|
|
|
|
if (get_immediate_dominator (CDI_DOMINATORS, true_edge->dest) != bb
|
|
|
|
|| phi_nodes (true_edge->dest))
|
|
|
|
{
|
|
|
|
unsigned avail_expr_limit;
|
|
|
|
unsigned const_and_copies_limit;
|
|
|
|
unsigned currdefs_limit;
|
|
|
|
|
|
|
|
avail_expr_limit
|
|
|
|
= bd->avail_exprs ? VARRAY_ACTIVE_SIZE (bd->avail_exprs) : 0;
|
|
|
|
const_and_copies_limit
|
|
|
|
= bd->const_and_copies ? VARRAY_ACTIVE_SIZE (bd->const_and_copies)
|
|
|
|
: 0;
|
|
|
|
currdefs_limit
|
|
|
|
= bd->block_defs ? VARRAY_ACTIVE_SIZE (bd->block_defs) : 0;
|
|
|
|
|
|
|
|
/* Record any equivalences created by following this edge. */
|
|
|
|
if (TREE_CODE_CLASS (cond_code) == '<')
|
|
|
|
{
|
|
|
|
record_cond (cond, boolean_true_node, &bd->avail_exprs);
|
|
|
|
record_cond (inverted, boolean_false_node, &bd->avail_exprs);
|
|
|
|
}
|
|
|
|
else if (cond_code == SSA_NAME)
|
|
|
|
record_const_or_copy (cond, boolean_true_node,
|
|
|
|
&bd->const_and_copies);
|
|
|
|
|
|
|
|
/* Now thread the edge. */
|
|
|
|
thread_across_edge (walk_data, true_edge);
|
|
|
|
|
|
|
|
/* And restore the various tables to their state before
|
|
|
|
we threaded this edge. */
|
|
|
|
remove_local_expressions_from_table (bd->avail_exprs,
|
|
|
|
avail_expr_limit,
|
|
|
|
avail_exprs);
|
|
|
|
restore_vars_to_original_value (bd->const_and_copies,
|
|
|
|
const_and_copies_limit,
|
|
|
|
const_and_copies);
|
|
|
|
restore_currdefs_to_original_value (bd->block_defs, currdefs_limit);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Similarly for the ELSE arm. */
|
|
|
|
if (get_immediate_dominator (CDI_DOMINATORS, false_edge->dest) != bb
|
|
|
|
|| phi_nodes (false_edge->dest))
|
|
|
|
{
|
|
|
|
/* Record any equivalences created by following this edge. */
|
|
|
|
if (TREE_CODE_CLASS (cond_code) == '<')
|
|
|
|
{
|
|
|
|
record_cond (cond, boolean_false_node, &bd->avail_exprs);
|
|
|
|
record_cond (inverted, boolean_true_node, &bd->avail_exprs);
|
|
|
|
}
|
|
|
|
else if (cond_code == SSA_NAME)
|
|
|
|
record_const_or_copy (cond, boolean_false_node,
|
|
|
|
&bd->const_and_copies);
|
|
|
|
|
|
|
|
thread_across_edge (walk_data, false_edge);
|
|
|
|
|
|
|
|
/* No need to remove local expressions from our tables
|
|
|
|
or restore vars to their original value as that will
|
|
|
|
be done immediately below. */
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
remove_local_expressions_from_table (bd->avail_exprs, 0, avail_exprs);
|
|
|
|
restore_nonzero_vars_to_original_value (bd->nonzero_vars, 0, nonzero_vars);
|
|
|
|
restore_vars_to_original_value (bd->const_and_copies, 0, const_and_copies);
|
|
|
|
restore_currdefs_to_original_value (bd->block_defs, 0);
|
|
|
|
|
|
|
|
/* Remove VRP records associated with this basic block. They are no
|
|
|
|
longer valid.
|
|
|
|
|
|
|
|
To be efficient, we note which variables have had their values
|
|
|
|
constrained in this block. So walk over each variable in the
|
|
|
|
VRP_VARIABLEs array. */
|
|
|
|
while (bd->vrp_variables && VARRAY_ACTIVE_SIZE (bd->vrp_variables) > 0)
|
|
|
|
{
|
|
|
|
tree var = VARRAY_TOP_TREE (bd->vrp_variables);
|
|
|
|
|
|
|
|
/* Each variable has a stack of value range records. We want to
|
|
|
|
invalidate those associated with our basic block. So we walk
|
|
|
|
the array backwards popping off records associated with our
|
|
|
|
block. Once we hit a record not associated with our block
|
|
|
|
we are done. */
|
|
|
|
varray_type var_vrp_records = VARRAY_GENERIC_PTR (vrp_data,
|
|
|
|
SSA_NAME_VERSION (var));
|
|
|
|
|
|
|
|
while (VARRAY_ACTIVE_SIZE (var_vrp_records) > 0)
|
|
|
|
{
|
|
|
|
struct vrp_element *element
|
|
|
|
= (struct vrp_element *)VARRAY_TOP_GENERIC_PTR (var_vrp_records);
|
|
|
|
|
|
|
|
if (element->bb != bb)
|
|
|
|
break;
|
|
|
|
|
|
|
|
VARRAY_POP (var_vrp_records);
|
|
|
|
}
|
|
|
|
|
|
|
|
VARRAY_POP (bd->vrp_variables);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Re-scan operands in all statements that may have had new symbols
|
|
|
|
exposed. */
|
|
|
|
while (bd->stmts_to_rescan && VARRAY_ACTIVE_SIZE (bd->stmts_to_rescan) > 0)
|
|
|
|
{
|
|
|
|
tree stmt = VARRAY_TOP_TREE (bd->stmts_to_rescan);
|
|
|
|
VARRAY_POP (bd->stmts_to_rescan);
|
|
|
|
mark_new_vars_to_rename (stmt, vars_to_rename);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* PHI nodes can create equivalences too.
|
|
|
|
|
|
|
|
Ignoring any alternatives which are the same as the result, if
|
|
|
|
all the alternatives are equal, then the PHI node creates an
|
2004-05-18 04:53:55 +02:00
|
|
|
equivalence.
|
|
|
|
|
|
|
|
Additionally, if all the PHI alternatives are known to have a nonzero
|
|
|
|
value, then the result of this PHI is known to have a nonzero value,
|
|
|
|
even if we do not know its exact value. */
|
|
|
|
|
2004-05-13 08:41:07 +02:00
|
|
|
static void
|
|
|
|
record_equivalences_from_phis (struct dom_walk_data *walk_data, basic_block bb)
|
|
|
|
{
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
tree phi;
|
|
|
|
|
tree.h (PHI_CHAIN): New.
* tree.h (PHI_CHAIN): New.
* (tree-cfg.c, tree-dfa.c, tree-flow-inline.h, tree-into-ssa.c,
tree-outof-ssa.c, tree-phinodes.c, tree-pretty-print.c,
tree-ssa-alias.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-dse.c,
tree-ssa-live.c, tree-ssa-loop.c, tree-ssa-phiopt.c, tree-ssa-pre.c,
tree-ssa.c, tree-tailcall.c): Use PHI_CHAIN instead of TREE_CHAIN
when traversing a list of PHI_NODEs.
From-SVN: r83273
2004-06-17 01:03:34 +02:00
|
|
|
for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
|
2004-05-13 08:41:07 +02:00
|
|
|
{
|
|
|
|
tree lhs = PHI_RESULT (phi);
|
|
|
|
tree rhs = NULL;
|
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; i < PHI_NUM_ARGS (phi); i++)
|
|
|
|
{
|
|
|
|
tree t = PHI_ARG_DEF (phi, i);
|
|
|
|
|
|
|
|
if (TREE_CODE (t) == SSA_NAME || is_gimple_min_invariant (t))
|
|
|
|
{
|
|
|
|
/* Ignore alternatives which are the same as our LHS. */
|
|
|
|
if (operand_equal_p (lhs, t, 0))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/* If we have not processed an alternative yet, then set
|
|
|
|
RHS to this alternative. */
|
|
|
|
if (rhs == NULL)
|
|
|
|
rhs = t;
|
|
|
|
/* If we have processed an alternative (stored in RHS), then
|
|
|
|
see if it is equal to this one. If it isn't, then stop
|
|
|
|
the search. */
|
|
|
|
else if (! operand_equal_p (rhs, t, 0))
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we had no interesting alternatives, then all the RHS alternatives
|
|
|
|
must have been the same as LHS. */
|
|
|
|
if (!rhs)
|
|
|
|
rhs = lhs;
|
|
|
|
|
|
|
|
/* If we managed to iterate through each PHI alternative without
|
|
|
|
breaking out of the loop, then we have a PHI which may create
|
|
|
|
a useful equivalence. We do not need to record unwind data for
|
|
|
|
this, since this is a true assignment and not an equivalence
|
c-common.c, [...]: Fix comment typos.
* c-common.c, calls.c, cfgcleanup.c, cgraph.c, cgraphunit.c,
ddg.c, ddg.h, df.c, df.h, except.c, expr.c, flags.h,
fold-const.c, gcc.c, gimplify.c, haifa-sched.c,
modulo-sched.c, tree-inline.c, tree-into-ssa.c, tree-nested.c,
tree-nrv.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-live.c,
tree-ssa-loop.c, tree-ssa-pre.c, tree-tailcall.c, tree.h: Fix
comment typos. Follow spelling conventions.
From-SVN: r82439
2004-05-30 09:12:58 +02:00
|
|
|
inferred from a comparison. All uses of this ssa name are dominated
|
2004-05-13 08:41:07 +02:00
|
|
|
by this assignment, so unwinding just costs time and space. */
|
|
|
|
if (i == PHI_NUM_ARGS (phi)
|
|
|
|
&& may_propagate_copy (lhs, rhs))
|
|
|
|
set_value_for (lhs, rhs, const_and_copies);
|
|
|
|
|
2004-05-18 04:53:55 +02:00
|
|
|
/* Now see if we know anything about the nonzero property for the
|
|
|
|
result of this PHI. */
|
|
|
|
for (i = 0; i < PHI_NUM_ARGS (phi); i++)
|
|
|
|
{
|
|
|
|
if (!PHI_ARG_NONZERO (phi, i))
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (i == PHI_NUM_ARGS (phi))
|
|
|
|
bitmap_set_bit (nonzero_vars, SSA_NAME_VERSION (PHI_RESULT (phi)));
|
|
|
|
|
2004-05-13 08:41:07 +02:00
|
|
|
register_new_def (lhs, &bd->block_defs);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Record any equivalences created by the incoming edge to BB. If BB
|
|
|
|
has more than one incoming edge, then no equivalence is created. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_equivalences_from_incoming_edge (struct dom_walk_data *walk_data,
|
|
|
|
basic_block bb)
|
|
|
|
{
|
|
|
|
int edge_flags;
|
|
|
|
basic_block parent;
|
|
|
|
struct eq_expr_value eq_expr_value;
|
|
|
|
tree parent_block_last_stmt = NULL;
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
|
|
|
|
/* If our parent block ended with a control statment, then we may be
|
|
|
|
able to record some equivalences based on which outgoing edge from
|
|
|
|
the parent was followed. */
|
|
|
|
parent = get_immediate_dominator (CDI_DOMINATORS, bb);
|
|
|
|
if (parent)
|
|
|
|
{
|
|
|
|
parent_block_last_stmt = last_stmt (parent);
|
|
|
|
if (parent_block_last_stmt && !is_ctrl_stmt (parent_block_last_stmt))
|
|
|
|
parent_block_last_stmt = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
eq_expr_value.src = NULL;
|
|
|
|
eq_expr_value.dst = NULL;
|
|
|
|
|
|
|
|
/* If we have a single predecessor, then extract EDGE_FLAGS from
|
|
|
|
our single incoming edge. Otherwise clear EDGE_FLAGS and
|
|
|
|
PARENT_BLOCK_LAST_STMT since they're not needed. */
|
|
|
|
if (bb->pred
|
|
|
|
&& ! bb->pred->pred_next
|
|
|
|
&& parent_block_last_stmt
|
|
|
|
&& bb_for_stmt (parent_block_last_stmt) == bb->pred->src)
|
|
|
|
{
|
|
|
|
edge_flags = bb->pred->flags;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
edge_flags = 0;
|
|
|
|
parent_block_last_stmt = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If our parent block ended in a COND_EXPR, add any equivalences
|
|
|
|
created by the COND_EXPR to the hash table and initialize
|
|
|
|
EQ_EXPR_VALUE appropriately.
|
|
|
|
|
|
|
|
EQ_EXPR_VALUE is an assignment expression created when BB's immediate
|
|
|
|
dominator ends in a COND_EXPR statement whose predicate is of the form
|
|
|
|
'VAR == VALUE', where VALUE may be another variable or a constant.
|
|
|
|
This is used to propagate VALUE on the THEN_CLAUSE of that
|
|
|
|
conditional. This assignment is inserted in CONST_AND_COPIES so that
|
|
|
|
the copy and constant propagator can find more propagation
|
|
|
|
opportunities. */
|
|
|
|
if (parent_block_last_stmt
|
|
|
|
&& bb->pred->pred_next == NULL
|
|
|
|
&& TREE_CODE (parent_block_last_stmt) == COND_EXPR
|
|
|
|
&& (edge_flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE)))
|
|
|
|
eq_expr_value = get_eq_expr_value (parent_block_last_stmt,
|
|
|
|
(edge_flags & EDGE_TRUE_VALUE) != 0,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
bb,
|
|
|
|
&bd->vrp_variables);
|
2004-05-31 12:18:36 +02:00
|
|
|
/* Similarly when the parent block ended in a SWITCH_EXPR.
|
|
|
|
We can only know the value of the switch's condition if the dominator
|
|
|
|
parent is also the only predecessor of this block. */
|
2004-05-13 08:41:07 +02:00
|
|
|
else if (parent_block_last_stmt
|
|
|
|
&& bb->pred->pred_next == NULL
|
2004-05-31 12:18:36 +02:00
|
|
|
&& bb->pred->src == parent
|
2004-05-13 08:41:07 +02:00
|
|
|
&& TREE_CODE (parent_block_last_stmt) == SWITCH_EXPR)
|
|
|
|
{
|
|
|
|
tree switch_cond = SWITCH_COND (parent_block_last_stmt);
|
|
|
|
|
|
|
|
/* If the switch's condition is an SSA variable, then we may
|
|
|
|
know its value at each of the case labels. */
|
|
|
|
if (TREE_CODE (switch_cond) == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree switch_vec = SWITCH_LABELS (parent_block_last_stmt);
|
|
|
|
size_t i, n = TREE_VEC_LENGTH (switch_vec);
|
|
|
|
int case_count = 0;
|
|
|
|
tree match_case = NULL_TREE;
|
|
|
|
|
|
|
|
/* Search the case labels for those whose destination is
|
|
|
|
the current basic block. */
|
|
|
|
for (i = 0; i < n; ++i)
|
|
|
|
{
|
|
|
|
tree elt = TREE_VEC_ELT (switch_vec, i);
|
|
|
|
if (label_to_block (CASE_LABEL (elt)) == bb)
|
|
|
|
{
|
2004-05-31 12:18:36 +02:00
|
|
|
if (++case_count > 1 || CASE_HIGH (elt))
|
2004-05-13 08:41:07 +02:00
|
|
|
break;
|
|
|
|
match_case = elt;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we encountered precisely one CASE_LABEL_EXPR and it
|
|
|
|
was not the default case, or a case range, then we know
|
|
|
|
the exact value of SWITCH_COND which caused us to get to
|
|
|
|
this block. Record that equivalence in EQ_EXPR_VALUE. */
|
|
|
|
if (case_count == 1
|
2004-05-31 12:18:36 +02:00
|
|
|
&& match_case
|
2004-05-13 08:41:07 +02:00
|
|
|
&& CASE_LOW (match_case)
|
|
|
|
&& !CASE_HIGH (match_case))
|
|
|
|
{
|
|
|
|
eq_expr_value.dst = switch_cond;
|
|
|
|
eq_expr_value.src = CASE_LOW (match_case);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If EQ_EXPR_VALUE (VAR == VALUE) is given, register the VALUE as a
|
|
|
|
new value for VAR, so that occurrences of VAR can be replaced with
|
|
|
|
VALUE while re-writing the THEN arm of a COND_EXPR. */
|
|
|
|
if (eq_expr_value.src && eq_expr_value.dst)
|
|
|
|
record_equality (eq_expr_value.dst, eq_expr_value.src,
|
|
|
|
&bd->const_and_copies);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Dump SSA statistics on FILE. */
|
|
|
|
|
|
|
|
void
|
|
|
|
dump_dominator_optimization_stats (FILE *file)
|
|
|
|
{
|
|
|
|
long n_exprs;
|
|
|
|
|
|
|
|
fprintf (file, "Total number of statements: %6ld\n\n",
|
|
|
|
opt_stats.num_stmts);
|
|
|
|
fprintf (file, "Exprs considered for dominator optimizations: %6ld\n",
|
|
|
|
opt_stats.num_exprs_considered);
|
|
|
|
|
|
|
|
n_exprs = opt_stats.num_exprs_considered;
|
|
|
|
if (n_exprs == 0)
|
|
|
|
n_exprs = 1;
|
|
|
|
|
|
|
|
fprintf (file, " Redundant expressions eliminated: %6ld (%.0f%%)\n",
|
|
|
|
opt_stats.num_re, PERCENT (opt_stats.num_re,
|
|
|
|
n_exprs));
|
|
|
|
|
|
|
|
fprintf (file, "\nHash table statistics:\n");
|
|
|
|
|
|
|
|
fprintf (file, " avail_exprs: ");
|
|
|
|
htab_statistics (file, avail_exprs);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Dump SSA statistics on stderr. */
|
|
|
|
|
|
|
|
void
|
|
|
|
debug_dominator_optimization_stats (void)
|
|
|
|
{
|
|
|
|
dump_dominator_optimization_stats (stderr);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* Dump statistics for the hash table HTAB. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
htab_statistics (FILE *file, htab_t htab)
|
|
|
|
{
|
|
|
|
fprintf (file, "size %ld, %ld elements, %f collision/search ratio\n",
|
|
|
|
(long) htab_size (htab),
|
|
|
|
(long) htab_elements (htab),
|
|
|
|
htab_collisions (htab));
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Record the fact that VAR has a nonzero value, though we may not know
|
|
|
|
its exact value. Note that if VAR is already known to have a nonzero
|
|
|
|
value, then we do nothing. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_var_is_nonzero (tree var, varray_type *block_nonzero_vars_p)
|
|
|
|
{
|
|
|
|
int indx = SSA_NAME_VERSION (var);
|
|
|
|
|
|
|
|
if (bitmap_bit_p (nonzero_vars, indx))
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* Mark it in the global table. */
|
|
|
|
bitmap_set_bit (nonzero_vars, indx);
|
|
|
|
|
|
|
|
/* Record this SSA_NAME so that we can reset the global table
|
|
|
|
when we leave this block. */
|
|
|
|
if (! *block_nonzero_vars_p)
|
|
|
|
VARRAY_TREE_INIT (*block_nonzero_vars_p, 2, "block_nonzero_vars");
|
|
|
|
VARRAY_PUSH_TREE (*block_nonzero_vars_p, var);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Enter a statement into the true/false expression hash table indicating
|
|
|
|
that the condition COND has the value VALUE. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_cond (tree cond, tree value, varray_type *block_avail_exprs_p)
|
|
|
|
{
|
|
|
|
struct expr_hash_elt *element = xmalloc (sizeof (struct expr_hash_elt));
|
|
|
|
void **slot;
|
|
|
|
|
|
|
|
initialize_hash_element (cond, value, element);
|
|
|
|
|
|
|
|
slot = htab_find_slot_with_hash (avail_exprs, (void *)element,
|
|
|
|
element->hash, true);
|
|
|
|
if (*slot == NULL)
|
|
|
|
{
|
|
|
|
*slot = (void *) element;
|
|
|
|
if (! *block_avail_exprs_p)
|
|
|
|
VARRAY_TREE_INIT (*block_avail_exprs_p, 20, "block_avail_exprs");
|
|
|
|
VARRAY_PUSH_TREE (*block_avail_exprs_p, cond);
|
|
|
|
}
|
|
|
|
else
|
|
|
|
free (element);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* A helper function for record_const_or_copy and record_equality.
|
|
|
|
Do the work of recording the value and undo info. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_const_or_copy_1 (tree x, tree y, tree prev_x,
|
|
|
|
varray_type *block_const_and_copies_p)
|
|
|
|
{
|
|
|
|
set_value_for (x, y, const_and_copies);
|
|
|
|
|
|
|
|
if (!*block_const_and_copies_p)
|
|
|
|
VARRAY_TREE_INIT (*block_const_and_copies_p, 2, "block_const_and_copies");
|
|
|
|
VARRAY_PUSH_TREE (*block_const_and_copies_p, x);
|
|
|
|
VARRAY_PUSH_TREE (*block_const_and_copies_p, prev_x);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Record that X is equal to Y in const_and_copies. Record undo
|
|
|
|
information in the block-local varray. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_const_or_copy (tree x, tree y, varray_type *block_const_and_copies_p)
|
|
|
|
{
|
|
|
|
tree prev_x = get_value_for (x, const_and_copies);
|
|
|
|
|
|
|
|
if (TREE_CODE (y) == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree tmp = get_value_for (y, const_and_copies);
|
|
|
|
if (tmp)
|
|
|
|
y = tmp;
|
|
|
|
}
|
|
|
|
|
|
|
|
record_const_or_copy_1 (x, y, prev_x, block_const_and_copies_p);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Similarly, but assume that X and Y are the two operands of an EQ_EXPR.
|
|
|
|
This constrains the cases in which we may treat this as assignment. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_equality (tree x, tree y, varray_type *block_const_and_copies_p)
|
|
|
|
{
|
|
|
|
tree prev_x = NULL, prev_y = NULL;
|
|
|
|
|
|
|
|
if (TREE_CODE (x) == SSA_NAME)
|
|
|
|
prev_x = get_value_for (x, const_and_copies);
|
|
|
|
if (TREE_CODE (y) == SSA_NAME)
|
|
|
|
prev_y = get_value_for (y, const_and_copies);
|
|
|
|
|
|
|
|
/* If one of the previous values is invariant, then use that.
|
|
|
|
Otherwise it doesn't matter which value we choose, just so
|
|
|
|
long as we canonicalize on one value. */
|
|
|
|
if (TREE_INVARIANT (y))
|
|
|
|
;
|
|
|
|
else if (TREE_INVARIANT (x))
|
|
|
|
prev_x = x, x = y, y = prev_x, prev_x = prev_y;
|
|
|
|
else if (prev_x && TREE_INVARIANT (prev_x))
|
|
|
|
x = y, y = prev_x, prev_x = prev_y;
|
|
|
|
else if (prev_y)
|
|
|
|
y = prev_y;
|
|
|
|
|
|
|
|
/* After the swapping, we must have one SSA_NAME. */
|
|
|
|
if (TREE_CODE (x) != SSA_NAME)
|
|
|
|
return;
|
|
|
|
|
|
|
|
/* For IEEE, -0.0 == 0.0, so we don't necessarily know the sign of a
|
|
|
|
variable compared against zero. If we're honoring signed zeros,
|
|
|
|
then we cannot record this value unless we know that the value is
|
c-common.c, [...]: Fix comment typos.
* c-common.c, calls.c, cfgcleanup.c, cgraph.c, cgraphunit.c,
ddg.c, ddg.h, df.c, df.h, except.c, expr.c, flags.h,
fold-const.c, gcc.c, gimplify.c, haifa-sched.c,
modulo-sched.c, tree-inline.c, tree-into-ssa.c, tree-nested.c,
tree-nrv.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-live.c,
tree-ssa-loop.c, tree-ssa-pre.c, tree-tailcall.c, tree.h: Fix
comment typos. Follow spelling conventions.
From-SVN: r82439
2004-05-30 09:12:58 +02:00
|
|
|
nonzero. */
|
2004-05-13 08:41:07 +02:00
|
|
|
if (HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (x)))
|
|
|
|
&& (TREE_CODE (y) != REAL_CST
|
|
|
|
|| REAL_VALUES_EQUAL (dconst0, TREE_REAL_CST (y))))
|
|
|
|
return;
|
|
|
|
|
|
|
|
record_const_or_copy_1 (x, y, prev_x, block_const_and_copies_p);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* STMT is a MODIFY_EXPR for which we were unable to find RHS in the
|
|
|
|
hash tables. Try to simplify the RHS using whatever equivalences
|
|
|
|
we may have recorded.
|
|
|
|
|
|
|
|
If we are able to simplify the RHS, then lookup the simplified form in
|
|
|
|
the hash table and return the result. Otherwise return NULL. */
|
|
|
|
|
|
|
|
static tree
|
|
|
|
simplify_rhs_and_lookup_avail_expr (struct dom_walk_data *walk_data,
|
|
|
|
tree stmt,
|
|
|
|
stmt_ann_t ann,
|
|
|
|
int insert)
|
|
|
|
{
|
|
|
|
tree rhs = TREE_OPERAND (stmt, 1);
|
|
|
|
enum tree_code rhs_code = TREE_CODE (rhs);
|
|
|
|
tree result = NULL;
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
|
|
|
|
/* If we have lhs = ~x, look and see if we earlier had x = ~y.
|
|
|
|
In which case we can change this statement to be lhs = y.
|
|
|
|
Which can then be copy propagated.
|
|
|
|
|
|
|
|
Similarly for negation. */
|
|
|
|
if ((rhs_code == BIT_NOT_EXPR || rhs_code == NEGATE_EXPR)
|
|
|
|
&& TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
|
|
|
|
{
|
|
|
|
/* Get the definition statement for our RHS. */
|
|
|
|
tree rhs_def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
|
|
|
|
|
|
|
|
/* See if the RHS_DEF_STMT has the same form as our statement. */
|
|
|
|
if (TREE_CODE (rhs_def_stmt) == MODIFY_EXPR
|
|
|
|
&& TREE_CODE (TREE_OPERAND (rhs_def_stmt, 1)) == rhs_code)
|
|
|
|
{
|
|
|
|
tree rhs_def_operand;
|
|
|
|
|
|
|
|
rhs_def_operand = TREE_OPERAND (TREE_OPERAND (rhs_def_stmt, 1), 0);
|
|
|
|
|
|
|
|
/* Verify that RHS_DEF_OPERAND is a suitable SSA variable. */
|
|
|
|
if (TREE_CODE (rhs_def_operand) == SSA_NAME
|
|
|
|
&& ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs_def_operand))
|
|
|
|
result = update_rhs_and_lookup_avail_expr (stmt,
|
|
|
|
rhs_def_operand,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
ann,
|
|
|
|
insert);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we have z = (x OP C1), see if we earlier had x = y OP C2.
|
|
|
|
If OP is associative, create and fold (y OP C2) OP C1 which
|
|
|
|
should result in (y OP C3), use that as the RHS for the
|
|
|
|
assignment. Add minus to this, as we handle it specially below. */
|
|
|
|
if ((associative_tree_code (rhs_code) || rhs_code == MINUS_EXPR)
|
|
|
|
&& TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME
|
|
|
|
&& is_gimple_min_invariant (TREE_OPERAND (rhs, 1)))
|
|
|
|
{
|
|
|
|
tree rhs_def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));
|
|
|
|
|
|
|
|
/* See if the RHS_DEF_STMT has the same form as our statement. */
|
|
|
|
if (TREE_CODE (rhs_def_stmt) == MODIFY_EXPR)
|
|
|
|
{
|
|
|
|
tree rhs_def_rhs = TREE_OPERAND (rhs_def_stmt, 1);
|
|
|
|
enum tree_code rhs_def_code = TREE_CODE (rhs_def_rhs);
|
|
|
|
|
|
|
|
if (rhs_code == rhs_def_code
|
|
|
|
|| (rhs_code == PLUS_EXPR && rhs_def_code == MINUS_EXPR)
|
|
|
|
|| (rhs_code == MINUS_EXPR && rhs_def_code == PLUS_EXPR))
|
|
|
|
{
|
|
|
|
tree def_stmt_op0 = TREE_OPERAND (rhs_def_rhs, 0);
|
|
|
|
tree def_stmt_op1 = TREE_OPERAND (rhs_def_rhs, 1);
|
|
|
|
|
|
|
|
if (TREE_CODE (def_stmt_op0) == SSA_NAME
|
|
|
|
&& ! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def_stmt_op0)
|
|
|
|
&& is_gimple_min_invariant (def_stmt_op1))
|
|
|
|
{
|
|
|
|
tree outer_const = TREE_OPERAND (rhs, 1);
|
|
|
|
tree type = TREE_TYPE (TREE_OPERAND (stmt, 0));
|
|
|
|
tree t;
|
|
|
|
|
|
|
|
/* Ho hum. So fold will only operate on the outermost
|
|
|
|
thingy that we give it, so we have to build the new
|
|
|
|
expression in two pieces. This requires that we handle
|
|
|
|
combinations of plus and minus. */
|
|
|
|
if (rhs_def_code != rhs_code)
|
|
|
|
{
|
|
|
|
if (rhs_def_code == MINUS_EXPR)
|
|
|
|
t = build (MINUS_EXPR, type, outer_const, def_stmt_op1);
|
|
|
|
else
|
|
|
|
t = build (MINUS_EXPR, type, def_stmt_op1, outer_const);
|
|
|
|
rhs_code = PLUS_EXPR;
|
|
|
|
}
|
|
|
|
else if (rhs_def_code == MINUS_EXPR)
|
|
|
|
t = build (PLUS_EXPR, type, def_stmt_op1, outer_const);
|
|
|
|
else
|
|
|
|
t = build (rhs_def_code, type, def_stmt_op1, outer_const);
|
|
|
|
t = local_fold (t);
|
|
|
|
t = build (rhs_code, type, def_stmt_op0, t);
|
|
|
|
t = local_fold (t);
|
|
|
|
|
|
|
|
/* If the result is a suitable looking gimple expression,
|
|
|
|
then use it instead of the original for STMT. */
|
|
|
|
if (TREE_CODE (t) == SSA_NAME
|
|
|
|
|| (TREE_CODE_CLASS (TREE_CODE (t)) == '1'
|
|
|
|
&& TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME)
|
|
|
|
|| ((TREE_CODE_CLASS (TREE_CODE (t)) == '2'
|
|
|
|
|| TREE_CODE_CLASS (TREE_CODE (t)) == '<')
|
|
|
|
&& TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME
|
|
|
|
&& is_gimple_val (TREE_OPERAND (t, 1))))
|
|
|
|
result = update_rhs_and_lookup_avail_expr
|
|
|
|
(stmt, t, &bd->avail_exprs, ann, insert);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR
|
|
|
|
and BIT_AND_EXPR respectively if the first operand is greater
|
|
|
|
than zero and the second operand is an exact power of two. */
|
|
|
|
if ((rhs_code == TRUNC_DIV_EXPR || rhs_code == TRUNC_MOD_EXPR)
|
|
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (rhs, 0)))
|
|
|
|
&& integer_pow2p (TREE_OPERAND (rhs, 1)))
|
|
|
|
{
|
|
|
|
tree val;
|
|
|
|
tree op = TREE_OPERAND (rhs, 0);
|
|
|
|
|
|
|
|
if (TYPE_UNSIGNED (TREE_TYPE (op)))
|
|
|
|
{
|
|
|
|
val = integer_one_node;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
tree dummy_cond = walk_data->global_data;
|
|
|
|
|
|
|
|
if (! dummy_cond)
|
|
|
|
{
|
|
|
|
dummy_cond = build (GT_EXPR, boolean_type_node,
|
|
|
|
op, integer_zero_node);
|
|
|
|
dummy_cond = build (COND_EXPR, void_type_node,
|
|
|
|
dummy_cond, NULL, NULL);
|
|
|
|
walk_data->global_data = dummy_cond;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
TREE_SET_CODE (TREE_OPERAND (dummy_cond, 0), GT_EXPR);
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 0) = op;
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 1)
|
|
|
|
= integer_zero_node;
|
|
|
|
}
|
|
|
|
val = simplify_cond_and_lookup_avail_expr (dummy_cond,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
NULL, false);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (val && integer_onep (val))
|
|
|
|
{
|
|
|
|
tree t;
|
|
|
|
tree op0 = TREE_OPERAND (rhs, 0);
|
|
|
|
tree op1 = TREE_OPERAND (rhs, 1);
|
|
|
|
|
|
|
|
if (rhs_code == TRUNC_DIV_EXPR)
|
|
|
|
t = build (RSHIFT_EXPR, TREE_TYPE (op0), op0,
|
|
|
|
build_int_2 (tree_log2 (op1), 0));
|
|
|
|
else
|
|
|
|
t = build (BIT_AND_EXPR, TREE_TYPE (op0), op0,
|
|
|
|
local_fold (build (MINUS_EXPR, TREE_TYPE (op1),
|
|
|
|
op1, integer_one_node)));
|
|
|
|
|
|
|
|
result = update_rhs_and_lookup_avail_expr (stmt, t,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
ann, insert);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Transform ABS (X) into X or -X as appropriate. */
|
|
|
|
if (rhs_code == ABS_EXPR
|
|
|
|
&& INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (rhs, 0))))
|
|
|
|
{
|
|
|
|
tree val;
|
|
|
|
tree op = TREE_OPERAND (rhs, 0);
|
|
|
|
tree type = TREE_TYPE (op);
|
|
|
|
|
|
|
|
if (TYPE_UNSIGNED (type))
|
|
|
|
{
|
|
|
|
val = integer_zero_node;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
tree dummy_cond = walk_data->global_data;
|
|
|
|
|
|
|
|
if (! dummy_cond)
|
|
|
|
{
|
2004-05-14 19:51:05 +02:00
|
|
|
dummy_cond = build (LE_EXPR, boolean_type_node,
|
2004-05-13 08:41:07 +02:00
|
|
|
op, integer_zero_node);
|
|
|
|
dummy_cond = build (COND_EXPR, void_type_node,
|
|
|
|
dummy_cond, NULL, NULL);
|
|
|
|
walk_data->global_data = dummy_cond;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
2004-05-14 19:51:05 +02:00
|
|
|
TREE_SET_CODE (TREE_OPERAND (dummy_cond, 0), LE_EXPR);
|
2004-05-13 08:41:07 +02:00
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 0) = op;
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 1)
|
2004-06-09 17:07:03 +02:00
|
|
|
= fold_convert (type, integer_zero_node);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
val = simplify_cond_and_lookup_avail_expr (dummy_cond,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
NULL, false);
|
2004-05-14 19:51:05 +02:00
|
|
|
|
|
|
|
if (!val)
|
|
|
|
{
|
|
|
|
TREE_SET_CODE (TREE_OPERAND (dummy_cond, 0), GE_EXPR);
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 0) = op;
|
|
|
|
TREE_OPERAND (TREE_OPERAND (dummy_cond, 0), 1)
|
2004-06-09 17:07:03 +02:00
|
|
|
= fold_convert (type, integer_zero_node);
|
2004-05-14 19:51:05 +02:00
|
|
|
|
|
|
|
val = simplify_cond_and_lookup_avail_expr (dummy_cond,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
NULL, false);
|
|
|
|
|
|
|
|
if (val)
|
|
|
|
{
|
|
|
|
if (integer_zerop (val))
|
|
|
|
val = integer_one_node;
|
|
|
|
else if (integer_onep (val))
|
|
|
|
val = integer_zero_node;
|
|
|
|
}
|
|
|
|
}
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
if (val
|
|
|
|
&& (integer_onep (val) || integer_zerop (val)))
|
|
|
|
{
|
|
|
|
tree t;
|
|
|
|
|
|
|
|
if (integer_onep (val))
|
|
|
|
t = build1 (NEGATE_EXPR, TREE_TYPE (op), op);
|
|
|
|
else
|
|
|
|
t = op;
|
|
|
|
|
|
|
|
result = update_rhs_and_lookup_avail_expr (stmt, t,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
ann, insert);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Optimize *"foo" into 'f'. This is done here rather than
|
|
|
|
in fold to avoid problems with stuff like &*"foo". */
|
|
|
|
if (TREE_CODE (rhs) == INDIRECT_REF || TREE_CODE (rhs) == ARRAY_REF)
|
|
|
|
{
|
|
|
|
tree t = fold_read_from_constant_string (rhs);
|
|
|
|
|
|
|
|
if (t)
|
|
|
|
result = update_rhs_and_lookup_avail_expr (stmt, t,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
ann, insert);
|
|
|
|
}
|
|
|
|
|
|
|
|
return result;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* COND is a condition of the form:
|
|
|
|
|
|
|
|
x == const or x != const
|
|
|
|
|
|
|
|
Look back to x's defining statement and see if x is defined as
|
|
|
|
|
|
|
|
x = (type) y;
|
|
|
|
|
|
|
|
If const is unchanged if we convert it to type, then we can build
|
|
|
|
the equivalent expression:
|
|
|
|
|
|
|
|
|
|
|
|
y == const or y != const
|
|
|
|
|
|
|
|
Which may allow further optimizations.
|
|
|
|
|
|
|
|
Return the equivalent comparison or NULL if no such equivalent comparison
|
|
|
|
was found. */
|
|
|
|
|
|
|
|
static tree
|
|
|
|
find_equivalent_equality_comparison (tree cond)
|
|
|
|
{
|
|
|
|
tree op0 = TREE_OPERAND (cond, 0);
|
|
|
|
tree op1 = TREE_OPERAND (cond, 1);
|
|
|
|
tree def_stmt = SSA_NAME_DEF_STMT (op0);
|
|
|
|
|
|
|
|
/* OP0 might have been a parameter, so first make sure it
|
|
|
|
was defined by a MODIFY_EXPR. */
|
|
|
|
if (def_stmt && TREE_CODE (def_stmt) == MODIFY_EXPR)
|
|
|
|
{
|
|
|
|
tree def_rhs = TREE_OPERAND (def_stmt, 1);
|
|
|
|
|
|
|
|
/* Now make sure the RHS of the MODIFY_EXPR is a typecast. */
|
|
|
|
if ((TREE_CODE (def_rhs) == NOP_EXPR
|
|
|
|
|| TREE_CODE (def_rhs) == CONVERT_EXPR)
|
|
|
|
&& TREE_CODE (TREE_OPERAND (def_rhs, 0)) == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree def_rhs_inner = TREE_OPERAND (def_rhs, 0);
|
|
|
|
tree def_rhs_inner_type = TREE_TYPE (def_rhs_inner);
|
|
|
|
tree new;
|
|
|
|
|
|
|
|
if (TYPE_PRECISION (def_rhs_inner_type)
|
|
|
|
> TYPE_PRECISION (TREE_TYPE (def_rhs)))
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
/* What we want to prove is that if we convert OP1 to
|
|
|
|
the type of the object inside the NOP_EXPR that the
|
|
|
|
result is still equivalent to SRC.
|
|
|
|
|
|
|
|
If that is true, the build and return new equivalent
|
|
|
|
condition which uses the source of the typecast and the
|
|
|
|
new constant (which has only changed its type). */
|
|
|
|
new = build1 (TREE_CODE (def_rhs), def_rhs_inner_type, op1);
|
|
|
|
new = local_fold (new);
|
|
|
|
if (is_gimple_val (new) && tree_int_cst_equal (new, op1))
|
|
|
|
return build (TREE_CODE (cond), TREE_TYPE (cond),
|
|
|
|
def_rhs_inner, new);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* STMT is a COND_EXPR for which we could not trivially determine its
|
|
|
|
result. This routine attempts to find equivalent forms of the
|
|
|
|
condition which we may be able to optimize better. It also
|
|
|
|
uses simple value range propagation to optimize conditionals. */
|
|
|
|
|
|
|
|
static tree
|
|
|
|
simplify_cond_and_lookup_avail_expr (tree stmt,
|
|
|
|
varray_type *block_avail_exprs_p,
|
|
|
|
stmt_ann_t ann,
|
|
|
|
int insert)
|
|
|
|
{
|
|
|
|
tree cond = COND_EXPR_COND (stmt);
|
|
|
|
|
|
|
|
if (TREE_CODE_CLASS (TREE_CODE (cond)) == '<')
|
|
|
|
{
|
|
|
|
tree op0 = TREE_OPERAND (cond, 0);
|
|
|
|
tree op1 = TREE_OPERAND (cond, 1);
|
|
|
|
|
|
|
|
if (TREE_CODE (op0) == SSA_NAME && is_gimple_min_invariant (op1))
|
|
|
|
{
|
|
|
|
int limit;
|
|
|
|
tree low, high, cond_low, cond_high;
|
|
|
|
int lowequal, highequal, swapped, no_overlap, subset, cond_inverted;
|
|
|
|
varray_type vrp_records;
|
|
|
|
struct vrp_element *element;
|
|
|
|
|
|
|
|
/* First see if we have test of an SSA_NAME against a constant
|
|
|
|
where the SSA_NAME is defined by an earlier typecast which
|
|
|
|
is irrelevant when performing tests against the given
|
|
|
|
constant. */
|
|
|
|
if (TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
|
|
|
|
{
|
|
|
|
tree new_cond = find_equivalent_equality_comparison (cond);
|
|
|
|
|
|
|
|
if (new_cond)
|
|
|
|
{
|
|
|
|
/* Update the statement to use the new equivalent
|
|
|
|
condition. */
|
|
|
|
COND_EXPR_COND (stmt) = new_cond;
|
|
|
|
ann->modified = 1;
|
|
|
|
|
|
|
|
/* Lookup the condition and return its known value if it
|
|
|
|
exists. */
|
|
|
|
new_cond = lookup_avail_expr (stmt, block_avail_exprs_p,
|
|
|
|
insert);
|
|
|
|
if (new_cond)
|
|
|
|
return new_cond;
|
|
|
|
|
|
|
|
/* The operands have changed, so update op0 and op1. */
|
|
|
|
op0 = TREE_OPERAND (cond, 0);
|
|
|
|
op1 = TREE_OPERAND (cond, 1);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Consult the value range records for this variable (if they exist)
|
|
|
|
to see if we can eliminate or simplify this conditional.
|
|
|
|
|
|
|
|
Note two tests are necessary to determine no records exist.
|
|
|
|
First we have to see if the virtual array exists, if it
|
|
|
|
exists, then we have to check its active size.
|
|
|
|
|
|
|
|
Also note the vast majority of conditionals are not testing
|
|
|
|
a variable which has had its range constrained by an earlier
|
|
|
|
conditional. So this filter avoids a lot of unnecessary work. */
|
|
|
|
vrp_records = VARRAY_GENERIC_PTR (vrp_data, SSA_NAME_VERSION (op0));
|
|
|
|
if (vrp_records == NULL)
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
limit = VARRAY_ACTIVE_SIZE (vrp_records);
|
|
|
|
|
|
|
|
/* If we have no value range records for this variable, or we are
|
|
|
|
unable to extract a range for this condition, then there is
|
|
|
|
nothing to do. */
|
|
|
|
if (limit == 0
|
|
|
|
|| ! extract_range_from_cond (cond, &cond_high,
|
|
|
|
&cond_low, &cond_inverted))
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
/* We really want to avoid unnecessary computations of range
|
|
|
|
info. So all ranges are computed lazily; this avoids a
|
|
|
|
lot of unnecessary work. ie, we record the conditional,
|
|
|
|
but do not process how it constrains the variable's
|
|
|
|
potential values until we know that processing the condition
|
|
|
|
could be helpful.
|
|
|
|
|
|
|
|
However, we do not want to have to walk a potentially long
|
|
|
|
list of ranges, nor do we want to compute a variable's
|
|
|
|
range more than once for a given path.
|
|
|
|
|
|
|
|
Luckily, each time we encounter a conditional that can not
|
|
|
|
be otherwise optimized we will end up here and we will
|
|
|
|
compute the necessary range information for the variable
|
|
|
|
used in this condition.
|
|
|
|
|
|
|
|
Thus you can conclude that there will never be more than one
|
|
|
|
conditional associated with a variable which has not been
|
|
|
|
processed. So we never need to merge more than one new
|
|
|
|
conditional into the current range.
|
|
|
|
|
|
|
|
These properties also help us avoid unnecessary work. */
|
|
|
|
element
|
|
|
|
= (struct vrp_element *)VARRAY_GENERIC_PTR (vrp_records, limit - 1);
|
|
|
|
|
|
|
|
if (element->high && element->low)
|
|
|
|
{
|
|
|
|
/* The last element has been processed, so there is no range
|
|
|
|
merging to do, we can simply use the high/low values
|
|
|
|
recorded in the last element. */
|
|
|
|
low = element->low;
|
|
|
|
high = element->high;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
tree tmp_high, tmp_low;
|
|
|
|
int dummy;
|
|
|
|
|
|
|
|
/* The last element has not been processed. Process it now. */
|
|
|
|
extract_range_from_cond (element->cond, &tmp_high,
|
|
|
|
&tmp_low, &dummy);
|
|
|
|
|
|
|
|
/* If this is the only element, then no merging is necessary,
|
|
|
|
the high/low values from extract_range_from_cond are all
|
|
|
|
we need. */
|
|
|
|
if (limit == 1)
|
|
|
|
{
|
|
|
|
low = tmp_low;
|
|
|
|
high = tmp_high;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
/* Get the high/low value from the previous element. */
|
|
|
|
struct vrp_element *prev
|
|
|
|
= (struct vrp_element *)VARRAY_GENERIC_PTR (vrp_records,
|
|
|
|
limit - 2);
|
|
|
|
low = prev->low;
|
|
|
|
high = prev->high;
|
|
|
|
|
|
|
|
/* Merge in this element's range with the range from the
|
|
|
|
previous element.
|
|
|
|
|
|
|
|
The low value for the merged range is the maximum of
|
|
|
|
the previous low value and the low value of this record.
|
|
|
|
|
|
|
|
Similarly the high value for the merged range is the
|
|
|
|
minimum of the previous high value and the high value of
|
|
|
|
this record. */
|
|
|
|
low = (tree_int_cst_compare (low, tmp_low) == 1
|
|
|
|
? low : tmp_low);
|
|
|
|
high = (tree_int_cst_compare (high, tmp_high) == -1
|
|
|
|
? high : tmp_high);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* And record the computed range. */
|
|
|
|
element->low = low;
|
|
|
|
element->high = high;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
/* After we have constrained this variable's potential values,
|
|
|
|
we try to determine the result of the given conditional.
|
|
|
|
|
|
|
|
To simplify later tests, first determine if the current
|
|
|
|
low value is the same low value as the conditional.
|
|
|
|
Similarly for the current high value and the high value
|
|
|
|
for the conditional. */
|
|
|
|
lowequal = tree_int_cst_equal (low, cond_low);
|
|
|
|
highequal = tree_int_cst_equal (high, cond_high);
|
|
|
|
|
|
|
|
if (lowequal && highequal)
|
|
|
|
return (cond_inverted ? boolean_false_node : boolean_true_node);
|
|
|
|
|
|
|
|
/* To simplify the overlap/subset tests below we may want
|
|
|
|
to swap the two ranges so that the larger of the two
|
|
|
|
ranges occurs "first". */
|
|
|
|
swapped = 0;
|
|
|
|
if (tree_int_cst_compare (low, cond_low) == 1
|
|
|
|
|| (lowequal
|
|
|
|
&& tree_int_cst_compare (cond_high, high) == 1))
|
|
|
|
{
|
|
|
|
tree temp;
|
|
|
|
|
|
|
|
swapped = 1;
|
|
|
|
temp = low;
|
|
|
|
low = cond_low;
|
|
|
|
cond_low = temp;
|
|
|
|
temp = high;
|
|
|
|
high = cond_high;
|
|
|
|
cond_high = temp;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Now determine if there is no overlap in the ranges
|
|
|
|
or if the second range is a subset of the first range. */
|
|
|
|
no_overlap = tree_int_cst_lt (high, cond_low);
|
|
|
|
subset = tree_int_cst_compare (cond_high, high) != 1;
|
|
|
|
|
|
|
|
/* If there was no overlap in the ranges, then this conditional
|
|
|
|
always has a false value (unless we had to invert this
|
|
|
|
conditional, in which case it always has a true value). */
|
|
|
|
if (no_overlap)
|
|
|
|
return (cond_inverted ? boolean_true_node : boolean_false_node);
|
|
|
|
|
|
|
|
/* If the current range is a subset of the condition's range,
|
|
|
|
then this conditional always has a true value (unless we
|
|
|
|
had to invert this conditional, in which case it always
|
|
|
|
has a true value). */
|
|
|
|
if (subset && swapped)
|
|
|
|
return (cond_inverted ? boolean_false_node : boolean_true_node);
|
|
|
|
|
|
|
|
/* We were unable to determine the result of the conditional.
|
|
|
|
However, we may be able to simplify the conditional. First
|
|
|
|
merge the ranges in the same manner as range merging above. */
|
|
|
|
low = tree_int_cst_compare (low, cond_low) == 1 ? low : cond_low;
|
|
|
|
high = tree_int_cst_compare (high, cond_high) == -1 ? high : cond_high;
|
|
|
|
|
|
|
|
/* If the range has converged to a single point, then turn this
|
|
|
|
into an equality comparison. */
|
|
|
|
if (TREE_CODE (cond) != EQ_EXPR
|
|
|
|
&& TREE_CODE (cond) != NE_EXPR
|
|
|
|
&& tree_int_cst_equal (low, high))
|
|
|
|
{
|
|
|
|
TREE_SET_CODE (cond, EQ_EXPR);
|
|
|
|
TREE_OPERAND (cond, 1) = high;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* STMT is a SWITCH_EXPR for which we could not trivially determine its
|
|
|
|
result. This routine attempts to find equivalent forms of the
|
|
|
|
condition which we may be able to optimize better. */
|
|
|
|
|
|
|
|
static tree
|
|
|
|
simplify_switch_and_lookup_avail_expr (tree stmt,
|
|
|
|
varray_type *block_avail_exprs_p,
|
|
|
|
stmt_ann_t ann,
|
|
|
|
int insert)
|
|
|
|
{
|
|
|
|
tree cond = SWITCH_COND (stmt);
|
|
|
|
tree def, to, ti;
|
|
|
|
|
|
|
|
/* The optimization that we really care about is removing unnecessary
|
|
|
|
casts. That will let us do much better in propagating the inferred
|
|
|
|
constant at the switch target. */
|
|
|
|
if (TREE_CODE (cond) == SSA_NAME)
|
|
|
|
{
|
|
|
|
def = SSA_NAME_DEF_STMT (cond);
|
|
|
|
if (TREE_CODE (def) == MODIFY_EXPR)
|
|
|
|
{
|
|
|
|
def = TREE_OPERAND (def, 1);
|
|
|
|
if (TREE_CODE (def) == NOP_EXPR)
|
|
|
|
{
|
|
|
|
def = TREE_OPERAND (def, 0);
|
|
|
|
to = TREE_TYPE (cond);
|
|
|
|
ti = TREE_TYPE (def);
|
|
|
|
|
|
|
|
/* If we have an extension that preserves sign, then we
|
|
|
|
can copy the source value into the switch. */
|
|
|
|
if (TYPE_UNSIGNED (to) == TYPE_UNSIGNED (ti)
|
|
|
|
&& TYPE_PRECISION (to) >= TYPE_PRECISION (ti)
|
|
|
|
&& is_gimple_val (def))
|
|
|
|
{
|
|
|
|
SWITCH_COND (stmt) = def;
|
|
|
|
ann->modified = 1;
|
|
|
|
|
|
|
|
return lookup_avail_expr (stmt, block_avail_exprs_p, insert);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Propagate known constants/copies into PHI nodes of BB's successor
|
|
|
|
blocks. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
cprop_into_phis (struct dom_walk_data *walk_data ATTRIBUTE_UNUSED,
|
|
|
|
basic_block bb)
|
|
|
|
{
|
2004-05-18 04:53:55 +02:00
|
|
|
cprop_into_successor_phis (bb, const_and_copies, nonzero_vars);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
|
|
|
|
/* Search for redundant computations in STMT. If any are found, then
|
|
|
|
replace them with the variable holding the result of the computation.
|
|
|
|
|
|
|
|
If safe, record this expression into the available expression hash
|
|
|
|
table. */
|
|
|
|
|
|
|
|
static bool
|
|
|
|
eliminate_redundant_computations (struct dom_walk_data *walk_data,
|
|
|
|
tree stmt, stmt_ann_t ann)
|
|
|
|
{
|
2004-06-10 23:41:08 +02:00
|
|
|
v_may_def_optype v_may_defs = V_MAY_DEF_OPS (ann);
|
2004-05-13 08:41:07 +02:00
|
|
|
tree *expr_p, def = NULL_TREE;
|
|
|
|
bool insert = true;
|
|
|
|
tree cached_lhs;
|
|
|
|
bool retval = false;
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
|
|
|
|
if (TREE_CODE (stmt) == MODIFY_EXPR)
|
|
|
|
def = TREE_OPERAND (stmt, 0);
|
|
|
|
|
|
|
|
/* Certain expressions on the RHS can be optimized away, but can not
|
|
|
|
themselves be entered into the hash tables. */
|
|
|
|
if (ann->makes_aliased_stores
|
|
|
|
|| ! def
|
|
|
|
|| TREE_CODE (def) != SSA_NAME
|
|
|
|
|| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (def)
|
2004-06-10 23:41:08 +02:00
|
|
|
|| NUM_V_MAY_DEFS (v_may_defs) != 0)
|
2004-05-13 08:41:07 +02:00
|
|
|
insert = false;
|
|
|
|
|
|
|
|
/* Check if the expression has been computed before. */
|
|
|
|
cached_lhs = lookup_avail_expr (stmt, &bd->avail_exprs, insert);
|
|
|
|
|
|
|
|
/* If this is an assignment and the RHS was not in the hash table,
|
|
|
|
then try to simplify the RHS and lookup the new RHS in the
|
|
|
|
hash table. */
|
|
|
|
if (! cached_lhs && TREE_CODE (stmt) == MODIFY_EXPR)
|
|
|
|
cached_lhs = simplify_rhs_and_lookup_avail_expr (walk_data,
|
|
|
|
stmt,
|
|
|
|
ann,
|
|
|
|
insert);
|
|
|
|
/* Similarly if this is a COND_EXPR and we did not find its
|
|
|
|
expression in the hash table, simplify the condition and
|
|
|
|
try again. */
|
|
|
|
else if (! cached_lhs && TREE_CODE (stmt) == COND_EXPR)
|
|
|
|
cached_lhs = simplify_cond_and_lookup_avail_expr (stmt,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
ann,
|
|
|
|
insert);
|
|
|
|
/* Similarly for a SWITCH_EXPR. */
|
|
|
|
else if (!cached_lhs && TREE_CODE (stmt) == SWITCH_EXPR)
|
|
|
|
cached_lhs = simplify_switch_and_lookup_avail_expr (stmt,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
ann,
|
|
|
|
insert);
|
|
|
|
|
|
|
|
opt_stats.num_exprs_considered++;
|
|
|
|
|
|
|
|
/* Get a pointer to the expression we are trying to optimize. */
|
|
|
|
if (TREE_CODE (stmt) == COND_EXPR)
|
|
|
|
expr_p = &COND_EXPR_COND (stmt);
|
|
|
|
else if (TREE_CODE (stmt) == SWITCH_EXPR)
|
|
|
|
expr_p = &SWITCH_COND (stmt);
|
|
|
|
else if (TREE_CODE (stmt) == RETURN_EXPR && TREE_OPERAND (stmt, 0))
|
|
|
|
expr_p = &TREE_OPERAND (TREE_OPERAND (stmt, 0), 1);
|
|
|
|
else
|
|
|
|
expr_p = &TREE_OPERAND (stmt, 1);
|
|
|
|
|
|
|
|
/* It is safe to ignore types here since we have already done
|
|
|
|
type checking in the hashing and equality routines. In fact
|
|
|
|
type checking here merely gets in the way of constant
|
|
|
|
propagation. Also, make sure that it is safe to propagate
|
|
|
|
CACHED_LHS into *EXPR_P. */
|
|
|
|
if (cached_lhs
|
|
|
|
&& (TREE_CODE (cached_lhs) != SSA_NAME
|
|
|
|
|| may_propagate_copy (cached_lhs, *expr_p)))
|
|
|
|
{
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
|
|
{
|
|
|
|
fprintf (dump_file, " Replaced redundant expr '");
|
|
|
|
print_generic_expr (dump_file, *expr_p, dump_flags);
|
|
|
|
fprintf (dump_file, "' with '");
|
|
|
|
print_generic_expr (dump_file, cached_lhs, dump_flags);
|
|
|
|
fprintf (dump_file, "'\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
opt_stats.num_re++;
|
|
|
|
|
|
|
|
#if defined ENABLE_CHECKING
|
|
|
|
if (TREE_CODE (cached_lhs) != SSA_NAME
|
|
|
|
&& !is_gimple_min_invariant (cached_lhs))
|
|
|
|
abort ();
|
|
|
|
#endif
|
|
|
|
|
|
|
|
if (TREE_CODE (cached_lhs) == ADDR_EXPR
|
|
|
|
|| (POINTER_TYPE_P (TREE_TYPE (*expr_p))
|
|
|
|
&& is_gimple_min_invariant (cached_lhs)))
|
|
|
|
retval = true;
|
|
|
|
|
|
|
|
propagate_value (expr_p, cached_lhs);
|
|
|
|
ann->modified = 1;
|
|
|
|
}
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* STMT, a MODIFY_EXPR, may create certain equivalences, in either
|
|
|
|
the available expressions table or the const_and_copies table.
|
|
|
|
Detect and record those equivalences. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_equivalences_from_stmt (tree stmt,
|
|
|
|
varray_type *block_avail_exprs_p,
|
|
|
|
varray_type *block_nonzero_vars_p,
|
|
|
|
int may_optimize_p,
|
|
|
|
stmt_ann_t ann)
|
|
|
|
{
|
|
|
|
tree lhs = TREE_OPERAND (stmt, 0);
|
|
|
|
enum tree_code lhs_code = TREE_CODE (lhs);
|
|
|
|
int i;
|
|
|
|
|
|
|
|
if (lhs_code == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree rhs = TREE_OPERAND (stmt, 1);
|
|
|
|
|
|
|
|
/* Strip away any useless type conversions. */
|
|
|
|
STRIP_USELESS_TYPE_CONVERSION (rhs);
|
|
|
|
|
|
|
|
/* If the RHS of the assignment is a constant or another variable that
|
|
|
|
may be propagated, register it in the CONST_AND_COPIES table. We
|
|
|
|
do not need to record unwind data for this, since this is a true
|
c-common.c, [...]: Fix comment typos.
* c-common.c, calls.c, cfgcleanup.c, cgraph.c, cgraphunit.c,
ddg.c, ddg.h, df.c, df.h, except.c, expr.c, flags.h,
fold-const.c, gcc.c, gimplify.c, haifa-sched.c,
modulo-sched.c, tree-inline.c, tree-into-ssa.c, tree-nested.c,
tree-nrv.c, tree-ssa-ccp.c, tree-ssa-dom.c, tree-ssa-live.c,
tree-ssa-loop.c, tree-ssa-pre.c, tree-tailcall.c, tree.h: Fix
comment typos. Follow spelling conventions.
From-SVN: r82439
2004-05-30 09:12:58 +02:00
|
|
|
assignment and not an equivalence inferred from a comparison. All
|
2004-05-13 08:41:07 +02:00
|
|
|
uses of this ssa name are dominated by this assignment, so unwinding
|
|
|
|
just costs time and space. */
|
|
|
|
if (may_optimize_p
|
|
|
|
&& (TREE_CODE (rhs) == SSA_NAME
|
|
|
|
|| is_gimple_min_invariant (rhs)))
|
|
|
|
set_value_for (lhs, rhs, const_and_copies);
|
|
|
|
|
|
|
|
/* alloca never returns zero and the address of a non-weak symbol
|
|
|
|
is never zero. NOP_EXPRs and CONVERT_EXPRs can be completely
|
|
|
|
stripped as they do not affect this equivalence. */
|
|
|
|
while (TREE_CODE (rhs) == NOP_EXPR
|
|
|
|
|| TREE_CODE (rhs) == CONVERT_EXPR)
|
|
|
|
rhs = TREE_OPERAND (rhs, 0);
|
|
|
|
|
|
|
|
if (alloca_call_p (rhs)
|
|
|
|
|| (TREE_CODE (rhs) == ADDR_EXPR
|
|
|
|
&& DECL_P (TREE_OPERAND (rhs, 0))
|
|
|
|
&& ! DECL_WEAK (TREE_OPERAND (rhs, 0))))
|
|
|
|
record_var_is_nonzero (lhs, block_nonzero_vars_p);
|
|
|
|
|
|
|
|
/* IOR of any value with a nonzero value will result in a nonzero
|
|
|
|
value. Even if we do not know the exact result recording that
|
|
|
|
the result is nonzero is worth the effort. */
|
|
|
|
if (TREE_CODE (rhs) == BIT_IOR_EXPR
|
|
|
|
&& integer_nonzerop (TREE_OPERAND (rhs, 1)))
|
|
|
|
record_var_is_nonzero (lhs, block_nonzero_vars_p);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Look at both sides for pointer dereferences. If we find one, then
|
|
|
|
the pointer must be nonnull and we can enter that equivalence into
|
|
|
|
the hash tables. */
|
2004-05-18 04:53:55 +02:00
|
|
|
if (flag_delete_null_pointer_checks)
|
|
|
|
for (i = 0; i < 2; i++)
|
|
|
|
{
|
|
|
|
tree t = TREE_OPERAND (stmt, i);
|
|
|
|
|
|
|
|
/* Strip away any COMPONENT_REFs. */
|
|
|
|
while (TREE_CODE (t) == COMPONENT_REF)
|
|
|
|
t = TREE_OPERAND (t, 0);
|
|
|
|
|
|
|
|
/* Now see if this is a pointer dereference. */
|
|
|
|
if (TREE_CODE (t) == INDIRECT_REF)
|
|
|
|
{
|
|
|
|
tree op = TREE_OPERAND (t, 0);
|
|
|
|
|
|
|
|
/* If the pointer is a SSA variable, then enter new
|
|
|
|
equivalences into the hash table. */
|
|
|
|
while (TREE_CODE (op) == SSA_NAME)
|
|
|
|
{
|
|
|
|
tree def = SSA_NAME_DEF_STMT (op);
|
|
|
|
|
|
|
|
record_var_is_nonzero (op, block_nonzero_vars_p);
|
|
|
|
|
|
|
|
/* And walk up the USE-DEF chains noting other SSA_NAMEs
|
|
|
|
which are known to have a nonzero value. */
|
|
|
|
if (def
|
|
|
|
&& TREE_CODE (def) == MODIFY_EXPR
|
|
|
|
&& TREE_CODE (TREE_OPERAND (def, 1)) == NOP_EXPR)
|
|
|
|
op = TREE_OPERAND (TREE_OPERAND (def, 1), 0);
|
|
|
|
else
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2004-05-13 08:41:07 +02:00
|
|
|
|
|
|
|
/* A memory store, even an aliased store, creates a useful
|
|
|
|
equivalence. By exchanging the LHS and RHS, creating suitable
|
|
|
|
vops and recording the result in the available expression table,
|
|
|
|
we may be able to expose more redundant loads. */
|
|
|
|
if (!ann->has_volatile_ops
|
|
|
|
&& (TREE_CODE (TREE_OPERAND (stmt, 1)) == SSA_NAME
|
|
|
|
|| is_gimple_min_invariant (TREE_OPERAND (stmt, 1)))
|
|
|
|
&& !is_gimple_reg (lhs))
|
|
|
|
{
|
|
|
|
tree rhs = TREE_OPERAND (stmt, 1);
|
|
|
|
tree new;
|
|
|
|
size_t j;
|
|
|
|
|
|
|
|
/* FIXME: If the LHS of the assignment is a bitfield and the RHS
|
|
|
|
is a constant, we need to adjust the constant to fit into the
|
|
|
|
type of the LHS. If the LHS is a bitfield and the RHS is not
|
|
|
|
a constant, then we can not record any equivalences for this
|
|
|
|
statement since we would need to represent the widening or
|
|
|
|
narrowing of RHS. This fixes gcc.c-torture/execute/921016-1.c
|
|
|
|
and should not be necessary if GCC represented bitfields
|
|
|
|
properly. */
|
|
|
|
if (lhs_code == COMPONENT_REF
|
|
|
|
&& DECL_BIT_FIELD (TREE_OPERAND (lhs, 1)))
|
|
|
|
{
|
|
|
|
if (TREE_CONSTANT (rhs))
|
|
|
|
rhs = widen_bitfield (rhs, TREE_OPERAND (lhs, 1), lhs);
|
|
|
|
else
|
|
|
|
rhs = NULL;
|
|
|
|
|
|
|
|
/* If the value overflowed, then we can not use this equivalence. */
|
|
|
|
if (rhs && ! is_gimple_min_invariant (rhs))
|
|
|
|
rhs = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (rhs)
|
|
|
|
{
|
2004-06-10 23:41:08 +02:00
|
|
|
v_may_def_optype v_may_defs = V_MAY_DEF_OPS (ann);
|
|
|
|
v_must_def_optype v_must_defs = V_MUST_DEF_OPS (ann);
|
2004-05-13 08:41:07 +02:00
|
|
|
|
|
|
|
/* Build a new statement with the RHS and LHS exchanged. */
|
|
|
|
new = build (MODIFY_EXPR, TREE_TYPE (stmt), rhs, lhs);
|
|
|
|
|
|
|
|
/* Get an annotation and set up the real operands. */
|
|
|
|
get_stmt_ann (new);
|
|
|
|
get_stmt_operands (new);
|
|
|
|
|
|
|
|
/* Clear out the virtual operands on the new statement, we are
|
|
|
|
going to set them explicitly below. */
|
|
|
|
remove_vuses (new);
|
2004-06-10 23:41:08 +02:00
|
|
|
remove_v_may_defs (new);
|
|
|
|
remove_v_must_defs (new);
|
2004-05-13 08:41:07 +02:00
|
|
|
|
|
|
|
start_ssa_stmt_operands (new);
|
|
|
|
/* For each VDEF on the original statement, we want to create a
|
2004-06-10 23:41:08 +02:00
|
|
|
VUSE of the V_MAY_DEF result or V_MUST_DEF op on the new
|
|
|
|
statement. */
|
|
|
|
for (j = 0; j < NUM_V_MAY_DEFS (v_may_defs); j++)
|
2004-05-13 08:41:07 +02:00
|
|
|
{
|
2004-06-10 23:41:08 +02:00
|
|
|
tree op = V_MAY_DEF_RESULT (v_may_defs, j);
|
|
|
|
add_vuse (op, new);
|
|
|
|
}
|
|
|
|
|
|
|
|
for (j = 0; j < NUM_V_MUST_DEFS (v_must_defs); j++)
|
|
|
|
{
|
|
|
|
tree op = V_MUST_DEF_OP (v_must_defs, j);
|
2004-05-13 08:41:07 +02:00
|
|
|
add_vuse (op, new);
|
|
|
|
}
|
|
|
|
|
|
|
|
finalize_ssa_stmt_operands (new);
|
|
|
|
|
|
|
|
/* Finally enter the statement into the available expression
|
|
|
|
table. */
|
|
|
|
lookup_avail_expr (new, block_avail_exprs_p, true);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Optimize the statement pointed by iterator SI.
|
|
|
|
|
|
|
|
We try to perform some simplistic global redundancy elimination and
|
|
|
|
constant propagation:
|
|
|
|
|
|
|
|
1- To detect global redundancy, we keep track of expressions that have
|
|
|
|
been computed in this block and its dominators. If we find that the
|
|
|
|
same expression is computed more than once, we eliminate repeated
|
|
|
|
computations by using the target of the first one.
|
|
|
|
|
|
|
|
2- Constant values and copy assignments. This is used to do very
|
|
|
|
simplistic constant and copy propagation. When a constant or copy
|
|
|
|
assignment is found, we map the value on the RHS of the assignment to
|
|
|
|
the variable in the LHS in the CONST_AND_COPIES table. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
optimize_stmt (struct dom_walk_data *walk_data,
|
|
|
|
basic_block bb ATTRIBUTE_UNUSED,
|
|
|
|
block_stmt_iterator si)
|
|
|
|
{
|
|
|
|
stmt_ann_t ann;
|
|
|
|
tree stmt;
|
|
|
|
bool may_optimize_p;
|
|
|
|
bool may_have_exposed_new_symbols = false;
|
|
|
|
struct dom_walk_block_data *bd
|
|
|
|
= VARRAY_TOP_GENERIC_PTR (walk_data->block_data_stack);
|
|
|
|
|
|
|
|
stmt = bsi_stmt (si);
|
|
|
|
|
|
|
|
get_stmt_operands (stmt);
|
|
|
|
ann = stmt_ann (stmt);
|
|
|
|
opt_stats.num_stmts++;
|
|
|
|
may_have_exposed_new_symbols = false;
|
|
|
|
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
|
|
{
|
|
|
|
fprintf (dump_file, "Optimizing statement ");
|
|
|
|
print_generic_stmt (dump_file, stmt, TDF_SLIM);
|
|
|
|
}
|
|
|
|
|
2004-06-10 23:41:08 +02:00
|
|
|
/* Const/copy propagate into USES, VUSES and the RHS of V_MAY_DEFs. */
|
2004-05-13 08:41:07 +02:00
|
|
|
may_have_exposed_new_symbols = cprop_into_stmt (stmt, const_and_copies);
|
|
|
|
|
|
|
|
/* If the statement has been modified with constant replacements,
|
|
|
|
fold its RHS before checking for redundant computations. */
|
|
|
|
if (ann->modified)
|
|
|
|
{
|
|
|
|
/* Try to fold the statement making sure that STMT is kept
|
|
|
|
up to date. */
|
|
|
|
if (fold_stmt (bsi_stmt_ptr (si)))
|
|
|
|
{
|
|
|
|
stmt = bsi_stmt (si);
|
|
|
|
ann = stmt_ann (stmt);
|
|
|
|
|
|
|
|
if (dump_file && (dump_flags & TDF_DETAILS))
|
|
|
|
{
|
|
|
|
fprintf (dump_file, " Folded to: ");
|
|
|
|
print_generic_stmt (dump_file, stmt, TDF_SLIM);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Constant/copy propagation above may change the set of
|
|
|
|
virtual operands associated with this statement. Folding
|
|
|
|
may remove the need for some virtual operands.
|
|
|
|
|
|
|
|
Indicate we will need to rescan and rewrite the statement. */
|
|
|
|
may_have_exposed_new_symbols = true;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Check for redundant computations. Do this optimization only
|
|
|
|
for assignments that have no volatile ops and conditionals. */
|
|
|
|
may_optimize_p = (!ann->has_volatile_ops
|
|
|
|
&& ((TREE_CODE (stmt) == RETURN_EXPR
|
|
|
|
&& TREE_OPERAND (stmt, 0)
|
|
|
|
&& TREE_CODE (TREE_OPERAND (stmt, 0)) == MODIFY_EXPR
|
|
|
|
&& ! (TREE_SIDE_EFFECTS
|
|
|
|
(TREE_OPERAND (TREE_OPERAND (stmt, 0), 1))))
|
|
|
|
|| (TREE_CODE (stmt) == MODIFY_EXPR
|
|
|
|
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (stmt, 1)))
|
|
|
|
|| TREE_CODE (stmt) == COND_EXPR
|
|
|
|
|| TREE_CODE (stmt) == SWITCH_EXPR));
|
|
|
|
|
|
|
|
if (may_optimize_p)
|
|
|
|
may_have_exposed_new_symbols
|
|
|
|
|= eliminate_redundant_computations (walk_data, stmt, ann);
|
|
|
|
|
|
|
|
/* Record any additional equivalences created by this statement. */
|
|
|
|
if (TREE_CODE (stmt) == MODIFY_EXPR)
|
|
|
|
record_equivalences_from_stmt (stmt,
|
|
|
|
&bd->avail_exprs,
|
|
|
|
&bd->nonzero_vars,
|
|
|
|
may_optimize_p,
|
|
|
|
ann);
|
|
|
|
|
|
|
|
register_definitions_for_stmt (ann, &bd->block_defs);
|
|
|
|
|
|
|
|
/* If STMT is a COND_EXPR and it was modified, then we may know
|
|
|
|
where it goes. If that is the case, then mark the CFG as altered.
|
|
|
|
|
|
|
|
This will cause us to later call remove_unreachable_blocks and
|
|
|
|
cleanup_tree_cfg when it is safe to do so. It is not safe to
|
|
|
|
clean things up here since removal of edges and such can trigger
|
|
|
|
the removal of PHI nodes, which in turn can release SSA_NAMEs to
|
|
|
|
the manager.
|
|
|
|
|
|
|
|
That's all fine and good, except that once SSA_NAMEs are released
|
|
|
|
to the manager, we must not call create_ssa_name until all references
|
|
|
|
to released SSA_NAMEs have been eliminated.
|
|
|
|
|
|
|
|
All references to the deleted SSA_NAMEs can not be eliminated until
|
|
|
|
we remove unreachable blocks.
|
|
|
|
|
|
|
|
We can not remove unreachable blocks until after we have completed
|
|
|
|
any queued jump threading.
|
|
|
|
|
|
|
|
We can not complete any queued jump threads until we have taken
|
|
|
|
appropriate variables out of SSA form. Taking variables out of
|
|
|
|
SSA form can call create_ssa_name and thus we lose.
|
|
|
|
|
|
|
|
Ultimately I suspect we're going to need to change the interface
|
|
|
|
into the SSA_NAME manager. */
|
|
|
|
|
|
|
|
if (ann->modified)
|
|
|
|
{
|
|
|
|
tree val = NULL;
|
|
|
|
|
|
|
|
if (TREE_CODE (stmt) == COND_EXPR)
|
|
|
|
val = COND_EXPR_COND (stmt);
|
|
|
|
else if (TREE_CODE (stmt) == SWITCH_EXPR)
|
|
|
|
val = SWITCH_COND (stmt);
|
|
|
|
|
|
|
|
if (val && TREE_CODE (val) == INTEGER_CST
|
|
|
|
&& find_taken_edge (bb_for_stmt (stmt), val))
|
|
|
|
cfg_altered = true;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (may_have_exposed_new_symbols)
|
|
|
|
{
|
|
|
|
if (! bd->stmts_to_rescan)
|
|
|
|
VARRAY_TREE_INIT (bd->stmts_to_rescan, 20, "stmts_to_rescan");
|
|
|
|
VARRAY_PUSH_TREE (bd->stmts_to_rescan, bsi_stmt (si));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Replace the RHS of STMT with NEW_RHS. If RHS can be found in the
|
|
|
|
available expression hashtable, then return the LHS from the hash
|
|
|
|
table.
|
|
|
|
|
|
|
|
If INSERT is true, then we also update the available expression
|
|
|
|
hash table to account for the changes made to STMT. */
|
|
|
|
|
|
|
|
static tree
|
|
|
|
update_rhs_and_lookup_avail_expr (tree stmt, tree new_rhs,
|
|
|
|
varray_type *block_avail_exprs_p,
|
|
|
|
stmt_ann_t ann,
|
|
|
|
bool insert)
|
|
|
|
{
|
|
|
|
tree cached_lhs = NULL;
|
|
|
|
|
|
|
|
/* Remove the old entry from the hash table. */
|
|
|
|
if (insert)
|
|
|
|
{
|
|
|
|
struct expr_hash_elt element;
|
|
|
|
|
|
|
|
initialize_hash_element (stmt, NULL, &element);
|
|
|
|
htab_remove_elt_with_hash (avail_exprs, &element, element.hash);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Now update the RHS of the assignment. */
|
|
|
|
TREE_OPERAND (stmt, 1) = new_rhs;
|
|
|
|
|
|
|
|
/* Now lookup the updated statement in the hash table. */
|
|
|
|
cached_lhs = lookup_avail_expr (stmt, block_avail_exprs_p, insert);
|
|
|
|
|
|
|
|
/* We have now called lookup_avail_expr twice with two different
|
|
|
|
versions of this same statement, once in optimize_stmt, once here.
|
|
|
|
|
|
|
|
We know the call in optimize_stmt did not find an existing entry
|
|
|
|
in the hash table, so a new entry was created. At the same time
|
|
|
|
this statement was pushed onto the BLOCK_AVAIL_EXPRS varray.
|
|
|
|
|
|
|
|
If this call failed to find an existing entry on the hash table,
|
|
|
|
then the new version of this statement was entered into the
|
|
|
|
hash table. And this statement was pushed onto BLOCK_AVAIL_EXPR
|
|
|
|
for the second time. So there are two copies on BLOCK_AVAIL_EXPRs
|
|
|
|
|
|
|
|
If this call succeeded, we still have one copy of this statement
|
|
|
|
on the BLOCK_AVAIL_EXPRs varray.
|
|
|
|
|
|
|
|
For both cases, we need to pop the most recent entry off the
|
|
|
|
BLOCK_AVAIL_EXPRs varray. For the case where we never found this
|
|
|
|
statement in the hash tables, that will leave precisely one
|
|
|
|
copy of this statement on BLOCK_AVAIL_EXPRs. For the case where
|
|
|
|
we found a copy of this statement in the second hash table lookup
|
|
|
|
we want _no_ copies of this statement in BLOCK_AVAIL_EXPRs. */
|
|
|
|
if (insert)
|
|
|
|
VARRAY_POP (*block_avail_exprs_p);
|
|
|
|
|
|
|
|
/* And make sure we record the fact that we modified this
|
|
|
|
statement. */
|
|
|
|
ann->modified = 1;
|
|
|
|
|
|
|
|
return cached_lhs;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Search for an existing instance of STMT in the AVAIL_EXPRS table. If
|
|
|
|
found, return its LHS. Otherwise insert STMT in the table and return
|
|
|
|
NULL_TREE.
|
|
|
|
|
|
|
|
Also, when an expression is first inserted in the AVAIL_EXPRS table, it
|
|
|
|
is also added to the stack pointed by BLOCK_AVAIL_EXPRS_P, so that they
|
|
|
|
can be removed when we finish processing this block and its children.
|
|
|
|
|
|
|
|
NOTE: This function assumes that STMT is a MODIFY_EXPR node that
|
|
|
|
contains no CALL_EXPR on its RHS and makes no volatile nor
|
|
|
|
aliased references. */
|
|
|
|
|
|
|
|
static tree
|
|
|
|
lookup_avail_expr (tree stmt, varray_type *block_avail_exprs_p, bool insert)
|
|
|
|
{
|
|
|
|
void **slot;
|
|
|
|
tree lhs;
|
|
|
|
tree temp;
|
|
|
|
struct expr_hash_elt *element = xcalloc (sizeof (struct expr_hash_elt), 1);
|
|
|
|
|
|
|
|
lhs = TREE_CODE (stmt) == MODIFY_EXPR ? TREE_OPERAND (stmt, 0) : NULL;
|
|
|
|
|
|
|
|
initialize_hash_element (stmt, lhs, element);
|
|
|
|
|
|
|
|
/* Don't bother remembering constant assignments and copy operations.
|
|
|
|
Constants and copy operations are handled by the constant/copy propagator
|
|
|
|
in optimize_stmt. */
|
|
|
|
if (TREE_CODE (element->rhs) == SSA_NAME
|
|
|
|
|| is_gimple_min_invariant (element->rhs))
|
|
|
|
{
|
|
|
|
free (element);
|
|
|
|
return NULL_TREE;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If this is an equality test against zero, see if we have recorded a
|
|
|
|
nonzero value for the variable in question. */
|
|
|
|
if ((TREE_CODE (element->rhs) == EQ_EXPR
|
|
|
|
|| TREE_CODE (element->rhs) == NE_EXPR)
|
|
|
|
&& TREE_CODE (TREE_OPERAND (element->rhs, 0)) == SSA_NAME
|
|
|
|
&& integer_zerop (TREE_OPERAND (element->rhs, 1)))
|
|
|
|
{
|
|
|
|
int indx = SSA_NAME_VERSION (TREE_OPERAND (element->rhs, 0));
|
|
|
|
|
|
|
|
if (bitmap_bit_p (nonzero_vars, indx))
|
|
|
|
{
|
|
|
|
tree t = element->rhs;
|
|
|
|
free (element);
|
|
|
|
|
|
|
|
if (TREE_CODE (t) == EQ_EXPR)
|
|
|
|
return boolean_false_node;
|
|
|
|
else
|
|
|
|
return boolean_true_node;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Finally try to find the expression in the main expression hash table. */
|
|
|
|
slot = htab_find_slot_with_hash (avail_exprs, element, element->hash,
|
|
|
|
(insert ? INSERT : NO_INSERT));
|
|
|
|
if (slot == NULL)
|
|
|
|
{
|
|
|
|
free (element);
|
|
|
|
return NULL_TREE;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (*slot == NULL)
|
|
|
|
{
|
|
|
|
*slot = (void *) element;
|
|
|
|
if (! *block_avail_exprs_p)
|
|
|
|
VARRAY_TREE_INIT (*block_avail_exprs_p, 20, "block_avail_exprs");
|
|
|
|
VARRAY_PUSH_TREE (*block_avail_exprs_p, stmt ? stmt : element->rhs);
|
|
|
|
return NULL_TREE;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Extract the LHS of the assignment so that it can be used as the current
|
|
|
|
definition of another variable. */
|
|
|
|
lhs = ((struct expr_hash_elt *)*slot)->lhs;
|
|
|
|
|
|
|
|
/* See if the LHS appears in the CONST_AND_COPIES table. If it does, then
|
|
|
|
use the value from the const_and_copies table. */
|
|
|
|
if (TREE_CODE (lhs) == SSA_NAME)
|
|
|
|
{
|
|
|
|
temp = get_value_for (lhs, const_and_copies);
|
|
|
|
if (temp)
|
|
|
|
lhs = temp;
|
|
|
|
}
|
|
|
|
|
|
|
|
free (element);
|
|
|
|
return lhs;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Given a condition COND, record into HI_P, LO_P and INVERTED_P the
|
|
|
|
range of values that result in the conditional having a true value.
|
|
|
|
|
|
|
|
Return true if we are successful in extracting a range from COND and
|
|
|
|
false if we are unsuccessful. */
|
|
|
|
|
|
|
|
static bool
|
|
|
|
extract_range_from_cond (tree cond, tree *hi_p, tree *lo_p, int *inverted_p)
|
|
|
|
{
|
|
|
|
tree op1 = TREE_OPERAND (cond, 1);
|
|
|
|
tree high, low, type;
|
|
|
|
int inverted;
|
|
|
|
|
|
|
|
/* Experiments have shown that it's rarely, if ever useful to
|
|
|
|
record ranges for enumerations. Presumably this is due to
|
|
|
|
the fact that they're rarely used directly. They are typically
|
|
|
|
cast into an integer type and used that way. */
|
|
|
|
if (TREE_CODE (TREE_TYPE (op1)) != INTEGER_TYPE)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
type = TREE_TYPE (op1);
|
|
|
|
|
|
|
|
switch (TREE_CODE (cond))
|
|
|
|
{
|
|
|
|
case EQ_EXPR:
|
|
|
|
high = low = op1;
|
|
|
|
inverted = 0;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case NE_EXPR:
|
|
|
|
high = low = op1;
|
|
|
|
inverted = 1;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case GE_EXPR:
|
|
|
|
low = op1;
|
|
|
|
high = TYPE_MAX_VALUE (type);
|
|
|
|
inverted = 0;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case GT_EXPR:
|
|
|
|
low = int_const_binop (PLUS_EXPR, op1, integer_one_node, 1);
|
|
|
|
high = TYPE_MAX_VALUE (type);
|
|
|
|
inverted = 0;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case LE_EXPR:
|
|
|
|
high = op1;
|
|
|
|
low = TYPE_MIN_VALUE (type);
|
|
|
|
inverted = 0;
|
|
|
|
break;
|
|
|
|
|
|
|
|
case LT_EXPR:
|
|
|
|
high = int_const_binop (MINUS_EXPR, op1, integer_one_node, 1);
|
|
|
|
low = TYPE_MIN_VALUE (type);
|
|
|
|
inverted = 0;
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
*hi_p = high;
|
|
|
|
*lo_p = low;
|
|
|
|
*inverted_p = inverted;
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Record a range created by COND for basic block BB. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
record_range (tree cond, basic_block bb, varray_type *vrp_variables_p)
|
|
|
|
{
|
|
|
|
/* We explicitly ignore NE_EXPRs. They rarely allow for meaningful
|
|
|
|
range optimizations and significantly complicate the implementation. */
|
|
|
|
if (TREE_CODE_CLASS (TREE_CODE (cond)) == '<'
|
|
|
|
&& TREE_CODE (cond) != NE_EXPR
|
|
|
|
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (cond, 1))) == INTEGER_TYPE)
|
|
|
|
{
|
|
|
|
struct vrp_element *element = ggc_alloc (sizeof (struct vrp_element));
|
|
|
|
int ssa_version = SSA_NAME_VERSION (TREE_OPERAND (cond, 0));
|
|
|
|
|
|
|
|
varray_type *vrp_records_p
|
|
|
|
= (varray_type *)&VARRAY_GENERIC_PTR (vrp_data, ssa_version);
|
|
|
|
|
|
|
|
element->low = NULL;
|
|
|
|
element->high = NULL;
|
|
|
|
element->cond = cond;
|
|
|
|
element->bb = bb;
|
|
|
|
|
|
|
|
if (*vrp_records_p == NULL)
|
|
|
|
{
|
|
|
|
VARRAY_GENERIC_PTR_INIT (*vrp_records_p, 2, "vrp records");
|
|
|
|
VARRAY_GENERIC_PTR (vrp_data, ssa_version) = *vrp_records_p;
|
|
|
|
}
|
|
|
|
|
|
|
|
VARRAY_PUSH_GENERIC_PTR (*vrp_records_p, element);
|
|
|
|
if (! *vrp_variables_p)
|
|
|
|
VARRAY_TREE_INIT (*vrp_variables_p, 2, "vrp_variables");
|
|
|
|
VARRAY_PUSH_TREE (*vrp_variables_p, TREE_OPERAND (cond, 0));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Given a conditional statement IF_STMT, return the assignment 'X = Y'
|
|
|
|
known to be true depending on which arm of IF_STMT is taken.
|
|
|
|
|
|
|
|
Not all conditional statements will result in a useful assignment.
|
|
|
|
Return NULL_TREE in that case.
|
|
|
|
|
|
|
|
Also enter into the available expression table statements of
|
|
|
|
the form:
|
|
|
|
|
|
|
|
TRUE ARM FALSE ARM
|
|
|
|
1 = cond 1 = cond'
|
|
|
|
0 = cond' 0 = cond
|
|
|
|
|
|
|
|
This allows us to lookup the condition in a dominated block and
|
|
|
|
get back a constant indicating if the condition is true. */
|
|
|
|
|
|
|
|
static struct eq_expr_value
|
|
|
|
get_eq_expr_value (tree if_stmt,
|
|
|
|
int true_arm,
|
|
|
|
varray_type *block_avail_exprs_p,
|
|
|
|
basic_block bb,
|
|
|
|
varray_type *vrp_variables_p)
|
|
|
|
{
|
|
|
|
tree cond;
|
|
|
|
struct eq_expr_value retval;
|
|
|
|
|
|
|
|
cond = COND_EXPR_COND (if_stmt);
|
|
|
|
retval.src = NULL;
|
|
|
|
retval.dst = NULL;
|
|
|
|
|
|
|
|
/* If the conditional is a single variable 'X', return 'X = 1' for
|
|
|
|
the true arm and 'X = 0' on the false arm. */
|
|
|
|
if (TREE_CODE (cond) == SSA_NAME)
|
|
|
|
{
|
|
|
|
retval.dst = cond;
|
|
|
|
retval.src = (true_arm ? integer_one_node : integer_zero_node);
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If we have a comparison expression, then record its result into
|
|
|
|
the available expression table. */
|
|
|
|
if (TREE_CODE_CLASS (TREE_CODE (cond)) == '<')
|
|
|
|
{
|
|
|
|
tree op0 = TREE_OPERAND (cond, 0);
|
|
|
|
tree op1 = TREE_OPERAND (cond, 1);
|
|
|
|
|
|
|
|
/* Special case comparing booleans against a constant as we know
|
|
|
|
the value of OP0 on both arms of the branch. ie, we can record
|
|
|
|
an equivalence for OP0 rather than COND. */
|
|
|
|
if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR)
|
|
|
|
&& TREE_CODE (op0) == SSA_NAME
|
|
|
|
&& TREE_CODE (TREE_TYPE (op0)) == BOOLEAN_TYPE
|
|
|
|
&& is_gimple_min_invariant (op1))
|
|
|
|
{
|
|
|
|
if ((TREE_CODE (cond) == EQ_EXPR && true_arm)
|
|
|
|
|| (TREE_CODE (cond) == NE_EXPR && ! true_arm))
|
|
|
|
{
|
|
|
|
retval.src = op1;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
if (integer_zerop (op1))
|
|
|
|
retval.src = boolean_true_node;
|
|
|
|
else
|
|
|
|
retval.src = boolean_false_node;
|
|
|
|
}
|
|
|
|
retval.dst = op0;
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (TREE_CODE (op0) == SSA_NAME
|
|
|
|
&& (is_gimple_min_invariant (op1) || TREE_CODE (op1) == SSA_NAME))
|
|
|
|
{
|
|
|
|
tree inverted = invert_truthvalue (cond);
|
|
|
|
|
|
|
|
/* When we find an available expression in the hash table, we replace
|
|
|
|
the expression with the LHS of the statement in the hash table.
|
|
|
|
|
|
|
|
So, we want to build statements such as "1 = <condition>" on the
|
|
|
|
true arm and "0 = <condition>" on the false arm. That way if we
|
|
|
|
find the expression in the table, we will replace it with its
|
|
|
|
known constant value. Also insert inversions of the result and
|
|
|
|
condition into the hash table. */
|
|
|
|
if (true_arm)
|
|
|
|
{
|
|
|
|
record_cond (cond, boolean_true_node, block_avail_exprs_p);
|
|
|
|
record_cond (inverted, boolean_false_node, block_avail_exprs_p);
|
|
|
|
|
|
|
|
if (TREE_CONSTANT (op1))
|
|
|
|
record_range (cond, bb, vrp_variables_p);
|
|
|
|
|
|
|
|
/* If the conditional is of the form 'X == Y', return 'X = Y'
|
|
|
|
for the true arm. */
|
|
|
|
if (TREE_CODE (cond) == EQ_EXPR)
|
|
|
|
{
|
|
|
|
retval.dst = op0;
|
|
|
|
retval.src = op1;
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
|
|
|
|
record_cond (inverted, boolean_true_node, block_avail_exprs_p);
|
|
|
|
record_cond (cond, boolean_false_node, block_avail_exprs_p);
|
|
|
|
|
|
|
|
if (TREE_CONSTANT (op1))
|
|
|
|
record_range (inverted, bb, vrp_variables_p);
|
|
|
|
|
|
|
|
/* If the conditional is of the form 'X != Y', return 'X = Y'
|
|
|
|
for the false arm. */
|
|
|
|
if (TREE_CODE (cond) == NE_EXPR)
|
|
|
|
{
|
|
|
|
retval.dst = op0;
|
|
|
|
retval.src = op1;
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
return retval;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Hashing and equality functions for AVAIL_EXPRS. The table stores
|
|
|
|
MODIFY_EXPR statements. We compute a value number for expressions using
|
|
|
|
the code of the expression and the SSA numbers of its operands. */
|
|
|
|
|
|
|
|
static hashval_t
|
|
|
|
avail_expr_hash (const void *p)
|
|
|
|
{
|
|
|
|
stmt_ann_t ann = ((struct expr_hash_elt *)p)->ann;
|
|
|
|
tree rhs = ((struct expr_hash_elt *)p)->rhs;
|
|
|
|
hashval_t val = 0;
|
|
|
|
size_t i;
|
|
|
|
vuse_optype vuses;
|
|
|
|
|
|
|
|
/* iterative_hash_expr knows how to deal with any expression and
|
|
|
|
deals with commutative operators as well, so just use it instead
|
|
|
|
of duplicating such complexities here. */
|
|
|
|
val = iterative_hash_expr (rhs, val);
|
|
|
|
|
|
|
|
/* If the hash table entry is not associated with a statement, then we
|
|
|
|
can just hash the expression and not worry about virtual operands
|
|
|
|
and such. */
|
|
|
|
if (!ann)
|
|
|
|
return val;
|
|
|
|
|
|
|
|
/* Add the SSA version numbers of every vuse operand. This is important
|
|
|
|
because compound variables like arrays are not renamed in the
|
|
|
|
operands. Rather, the rename is done on the virtual variable
|
|
|
|
representing all the elements of the array. */
|
|
|
|
vuses = VUSE_OPS (ann);
|
|
|
|
for (i = 0; i < NUM_VUSES (vuses); i++)
|
|
|
|
val = iterative_hash_expr (VUSE_OP (vuses, i), val);
|
|
|
|
|
|
|
|
return val;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
avail_expr_eq (const void *p1, const void *p2)
|
|
|
|
{
|
|
|
|
stmt_ann_t ann1 = ((struct expr_hash_elt *)p1)->ann;
|
|
|
|
tree rhs1 = ((struct expr_hash_elt *)p1)->rhs;
|
|
|
|
stmt_ann_t ann2 = ((struct expr_hash_elt *)p2)->ann;
|
|
|
|
tree rhs2 = ((struct expr_hash_elt *)p2)->rhs;
|
|
|
|
|
|
|
|
/* If they are the same physical expression, return true. */
|
|
|
|
if (rhs1 == rhs2 && ann1 == ann2)
|
|
|
|
return true;
|
|
|
|
|
|
|
|
/* If their codes are not equal, then quit now. */
|
|
|
|
if (TREE_CODE (rhs1) != TREE_CODE (rhs2))
|
|
|
|
return false;
|
|
|
|
|
|
|
|
/* In case of a collision, both RHS have to be identical and have the
|
|
|
|
same VUSE operands. */
|
|
|
|
if ((TREE_TYPE (rhs1) == TREE_TYPE (rhs2)
|
|
|
|
|| lang_hooks.types_compatible_p (TREE_TYPE (rhs1), TREE_TYPE (rhs2)))
|
|
|
|
&& operand_equal_p (rhs1, rhs2, OEP_PURE_SAME))
|
|
|
|
{
|
|
|
|
vuse_optype ops1 = NULL;
|
|
|
|
vuse_optype ops2 = NULL;
|
|
|
|
size_t num_ops1 = 0;
|
|
|
|
size_t num_ops2 = 0;
|
|
|
|
size_t i;
|
|
|
|
|
|
|
|
if (ann1)
|
|
|
|
{
|
|
|
|
ops1 = VUSE_OPS (ann1);
|
|
|
|
num_ops1 = NUM_VUSES (ops1);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (ann2)
|
|
|
|
{
|
|
|
|
ops2 = VUSE_OPS (ann2);
|
|
|
|
num_ops2 = NUM_VUSES (ops2);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* If the number of virtual uses is different, then we consider
|
|
|
|
them not equal. */
|
|
|
|
if (num_ops1 != num_ops2)
|
|
|
|
return false;
|
|
|
|
|
|
|
|
for (i = 0; i < num_ops1; i++)
|
|
|
|
if (VUSE_OP (ops1, i) != VUSE_OP (ops2, i))
|
|
|
|
return false;
|
|
|
|
|
|
|
|
#ifdef ENABLE_CHECKING
|
|
|
|
if (((struct expr_hash_elt *)p1)->hash
|
|
|
|
!= ((struct expr_hash_elt *)p2)->hash)
|
|
|
|
abort ();
|
|
|
|
#endif
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Given STMT and a pointer to the block local defintions BLOCK_DEFS_P,
|
|
|
|
register register all objects set by this statement into BLOCK_DEFS_P
|
|
|
|
and CURRDEFS. */
|
|
|
|
|
|
|
|
static void
|
|
|
|
register_definitions_for_stmt (stmt_ann_t ann, varray_type *block_defs_p)
|
|
|
|
{
|
|
|
|
def_optype defs;
|
2004-06-10 23:41:08 +02:00
|
|
|
v_may_def_optype v_may_defs;
|
|
|
|
v_must_def_optype v_must_defs;
|
2004-05-13 08:41:07 +02:00
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
defs = DEF_OPS (ann);
|
|
|
|
for (i = 0; i < NUM_DEFS (defs); i++)
|
|
|
|
{
|
|
|
|
tree def = DEF_OP (defs, i);
|
|
|
|
|
|
|
|
/* FIXME: We shouldn't be registering new defs if the variable
|
|
|
|
doesn't need to be renamed. */
|
|
|
|
register_new_def (def, block_defs_p);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Register new virtual definitions made by the statement. */
|
2004-06-10 23:41:08 +02:00
|
|
|
v_may_defs = V_MAY_DEF_OPS (ann);
|
|
|
|
for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++)
|
|
|
|
{
|
|
|
|
/* FIXME: We shouldn't be registering new defs if the variable
|
|
|
|
doesn't need to be renamed. */
|
|
|
|
register_new_def (V_MAY_DEF_RESULT (v_may_defs, i), block_defs_p);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Register new virtual mustdefs made by the statement. */
|
|
|
|
v_must_defs = V_MUST_DEF_OPS (ann);
|
|
|
|
for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++)
|
2004-05-13 08:41:07 +02:00
|
|
|
{
|
|
|
|
/* FIXME: We shouldn't be registering new defs if the variable
|
|
|
|
doesn't need to be renamed. */
|
2004-06-10 23:41:08 +02:00
|
|
|
register_new_def (V_MUST_DEF_OP (v_must_defs, i), block_defs_p);
|
2004-05-13 08:41:07 +02:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|