9925bce0b8
2009-04-22 Richard Guenther <rguenther@suse.de> PR tree-optimization/39845 * tree-switch-conversion.c (build_arrays): Add new referenced vars. (gen_inbound_check): Likewise. * gcc.c-torture/compile/pr39845.c: New testcase. From-SVN: r146569
929 lines
26 KiB
C
929 lines
26 KiB
C
/* Switch Conversion converts variable initializations based on switch
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statements to initializations from a static array.
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Copyright (C) 2006, 2008 Free Software Foundation, Inc.
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Contributed by Martin Jambor <jamborm@suse.cz>
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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 it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any
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later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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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 COPYING3. If not, write to the Free
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Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA. */
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/*
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Switch initialization conversion
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The following pass changes simple initializations of scalars in a switch
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statement into initializations from a static array. Obviously, the values must
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be constant and known at compile time and a default branch must be
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provided. For example, the following code:
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int a,b;
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switch (argc)
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{
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case 1:
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case 2:
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a_1 = 8;
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b_1 = 6;
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break;
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case 3:
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a_2 = 9;
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b_2 = 5;
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break;
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case 12:
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a_3 = 10;
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b_3 = 4;
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break;
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default:
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a_4 = 16;
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b_4 = 1;
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}
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a_5 = PHI <a_1, a_2, a_3, a_4>
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b_5 = PHI <b_1, b_2, b_3, b_4>
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is changed into:
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static const int = CSWTCH01[] = {6, 6, 5, 1, 1, 1, 1, 1, 1, 1, 1, 4};
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static const int = CSWTCH02[] = {8, 8, 9, 16, 16, 16, 16, 16, 16, 16,
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16, 16, 10};
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if (((unsigned) argc) - 1 < 11)
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{
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a_6 = CSWTCH02[argc - 1];
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b_6 = CSWTCH01[argc - 1];
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}
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else
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{
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a_7 = 16;
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b_7 = 1;
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}
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a_5 = PHI <a_6, a_7>
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b_b = PHI <b_6, b_7>
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There are further constraints. Specifically, the range of values across all
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case labels must not be bigger than SWITCH_CONVERSION_BRANCH_RATIO (default
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eight) times the number of the actual switch branches. */
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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 <signal.h>
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#include "line-map.h"
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#include "params.h"
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#include "flags.h"
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#include "tree.h"
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#include "basic-block.h"
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#include "tree-flow.h"
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#include "tree-flow-inline.h"
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#include "tree-ssa-operands.h"
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#include "output.h"
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#include "input.h"
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#include "tree-pass.h"
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#include "diagnostic.h"
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#include "tree-dump.h"
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#include "timevar.h"
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/* The main structure of the pass. */
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struct switch_conv_info
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{
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/* The expression used to decide the switch branch. (It is subsequently used
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as the index to the created array.) */
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tree index_expr;
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/* The following integer constants store the minimum value covered by the
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cases. */
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tree range_min;
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/* The difference between the above two numbers, i.e. The size of the array
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that would have to be created by the transformation. */
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tree range_size;
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/* Basic block that contains the actual SWITCH_EXPR. */
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basic_block switch_bb;
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/* All branches of the switch statement must have a single successor stored in
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the following variable. */
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basic_block final_bb;
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/* Number of phi nodes in the final bb (that we'll be replacing). */
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int phi_count;
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/* Array of default values, in the same order as phi nodes. */
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tree *default_values;
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/* Constructors of new static arrays. */
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VEC (constructor_elt, gc) **constructors;
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/* Array of ssa names that are initialized with a value from a new static
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array. */
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tree *target_inbound_names;
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/* Array of ssa names that are initialized with the default value if the
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switch expression is out of range. */
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tree *target_outbound_names;
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/* The probability of the default edge in the replaced switch. */
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int default_prob;
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/* The count of the default edge in the replaced switch. */
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gcov_type default_count;
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/* Combined count of all other (non-default) edges in the replaced switch. */
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gcov_type other_count;
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/* The first load statement that loads a temporary from a new static array.
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*/
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gimple arr_ref_first;
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/* The last load statement that loads a temporary from a new static array. */
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gimple arr_ref_last;
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/* String reason why the case wasn't a good candidate that is written to the
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dump file, if there is one. */
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const char *reason;
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};
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/* Global pass info. */
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static struct switch_conv_info info;
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/* Checks whether the range given by individual case statements of the SWTCH
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switch statement isn't too big and whether the number of branches actually
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satisfies the size of the new array. */
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static bool
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check_range (gimple swtch)
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{
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tree min_case, max_case;
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unsigned int branch_num = gimple_switch_num_labels (swtch);
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tree range_max;
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/* The gimplifier has already sorted the cases by CASE_LOW and ensured there
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is a default label which is the last in the vector. */
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min_case = gimple_switch_label (swtch, 1);
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info.range_min = CASE_LOW (min_case);
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gcc_assert (branch_num > 1);
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gcc_assert (CASE_LOW (gimple_switch_label (swtch, 0)) == NULL_TREE);
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max_case = gimple_switch_label (swtch, branch_num - 1);
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if (CASE_HIGH (max_case) != NULL_TREE)
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range_max = CASE_HIGH (max_case);
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else
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range_max = CASE_LOW (max_case);
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gcc_assert (info.range_min);
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gcc_assert (range_max);
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info.range_size = int_const_binop (MINUS_EXPR, range_max, info.range_min, 0);
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gcc_assert (info.range_size);
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if (!host_integerp (info.range_size, 1))
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{
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info.reason = "index range way too large or otherwise unusable.\n";
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return false;
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}
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if ((unsigned HOST_WIDE_INT) tree_low_cst (info.range_size, 1)
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> ((unsigned) branch_num * SWITCH_CONVERSION_BRANCH_RATIO))
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{
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info.reason = "the maximum range-branch ratio exceeded.\n";
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return false;
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}
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return true;
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}
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/* Checks the given CS switch case whether it is suitable for conversion
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(whether all but the default basic blocks are empty and so on). If it is,
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adds the case to the branch list along with values for the defined variables
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and returns true. Otherwise returns false. */
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static bool
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check_process_case (tree cs)
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{
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tree ldecl;
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basic_block label_bb, following_bb;
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edge e;
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ldecl = CASE_LABEL (cs);
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label_bb = label_to_block (ldecl);
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e = find_edge (info.switch_bb, label_bb);
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gcc_assert (e);
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if (CASE_LOW (cs) == NULL_TREE)
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{
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/* Default branch. */
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info.default_prob = e->probability;
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info.default_count = e->count;
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}
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else
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info.other_count += e->count;
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if (!label_bb)
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{
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info.reason = " Bad case - cs BB label is NULL\n";
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return false;
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}
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if (!single_pred_p (label_bb))
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{
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if (info.final_bb && info.final_bb != label_bb)
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{
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info.reason = " Bad case - a non-final BB has two predecessors\n";
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return false; /* sth complex going on in this branch */
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}
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following_bb = label_bb;
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}
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else
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{
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if (!empty_block_p (label_bb))
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{
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info.reason = " Bad case - a non-final BB not empty\n";
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return false;
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}
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e = single_succ_edge (label_bb);
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following_bb = single_succ (label_bb);
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}
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if (!info.final_bb)
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info.final_bb = following_bb;
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else if (info.final_bb != following_bb)
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{
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info.reason = " Bad case - different final BB\n";
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return false; /* the only successor is not common for all the branches */
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}
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return true;
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}
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/* This function checks whether all required values in phi nodes in final_bb
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are constants. Required values are those that correspond to a basic block
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which is a part of the examined switch statement. It returns true if the
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phi nodes are OK, otherwise false. */
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static bool
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check_final_bb (void)
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{
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gimple_stmt_iterator gsi;
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info.phi_count = 0;
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for (gsi = gsi_start_phis (info.final_bb); !gsi_end_p (gsi); gsi_next (&gsi))
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{
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gimple phi = gsi_stmt (gsi);
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unsigned int i;
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info.phi_count++;
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for (i = 0; i < gimple_phi_num_args (phi); i++)
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{
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basic_block bb = gimple_phi_arg_edge (phi, i)->src;
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if (bb == info.switch_bb
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|| (single_pred_p (bb) && single_pred (bb) == info.switch_bb))
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{
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tree reloc, val;
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val = gimple_phi_arg_def (phi, i);
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if (!is_gimple_ip_invariant (val))
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{
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info.reason = " Non-invariant value from a case\n";
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return false; /* Non-invariant argument. */
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}
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reloc = initializer_constant_valid_p (val, TREE_TYPE (val));
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if ((flag_pic && reloc != null_pointer_node)
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|| (!flag_pic && reloc == NULL_TREE))
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{
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if (reloc)
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info.reason
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= " Value from a case would need runtime relocations\n";
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else
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info.reason
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= " Value from a case is not a valid initializer\n";
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return false;
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}
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}
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}
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}
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return true;
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}
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/* The following function allocates default_values, target_{in,out}_names and
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constructors arrays. The last one is also populated with pointers to
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vectors that will become constructors of new arrays. */
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static void
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create_temp_arrays (void)
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{
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int i;
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info.default_values = (tree *) xcalloc (info.phi_count, sizeof (tree));
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info.constructors = (VEC (constructor_elt, gc) **) xcalloc (info.phi_count,
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sizeof (tree));
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info.target_inbound_names = (tree *) xcalloc (info.phi_count, sizeof (tree));
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info.target_outbound_names = (tree *) xcalloc (info.phi_count,
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sizeof (tree));
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for (i = 0; i < info.phi_count; i++)
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info.constructors[i]
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= VEC_alloc (constructor_elt, gc, tree_low_cst (info.range_size, 1) + 1);
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}
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/* Free the arrays created by create_temp_arrays(). The vectors that are
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created by that function are not freed here, however, because they have
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already become constructors and must be preserved. */
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static void
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free_temp_arrays (void)
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{
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free (info.constructors);
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free (info.default_values);
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free (info.target_inbound_names);
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free (info.target_outbound_names);
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}
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/* Populate the array of default values in the order of phi nodes.
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DEFAULT_CASE is the CASE_LABEL_EXPR for the default switch branch. */
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static void
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gather_default_values (tree default_case)
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{
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gimple_stmt_iterator gsi;
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basic_block bb = label_to_block (CASE_LABEL (default_case));
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edge e;
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int i = 0;
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gcc_assert (CASE_LOW (default_case) == NULL_TREE);
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if (bb == info.final_bb)
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e = find_edge (info.switch_bb, bb);
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else
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e = single_succ_edge (bb);
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for (gsi = gsi_start_phis (info.final_bb); !gsi_end_p (gsi); gsi_next (&gsi))
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{
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gimple phi = gsi_stmt (gsi);
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tree val = PHI_ARG_DEF_FROM_EDGE (phi, e);
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gcc_assert (val);
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info.default_values[i++] = val;
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}
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}
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/* The following function populates the vectors in the constructors array with
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future contents of the static arrays. The vectors are populated in the
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order of phi nodes. SWTCH is the switch statement being converted. */
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static void
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build_constructors (gimple swtch)
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{
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unsigned i, branch_num = gimple_switch_num_labels (swtch);
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tree pos = info.range_min;
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for (i = 1; i < branch_num; i++)
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{
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tree cs = gimple_switch_label (swtch, i);
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basic_block bb = label_to_block (CASE_LABEL (cs));
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edge e;
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tree high;
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gimple_stmt_iterator gsi;
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int j;
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if (bb == info.final_bb)
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e = find_edge (info.switch_bb, bb);
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else
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e = single_succ_edge (bb);
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gcc_assert (e);
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while (tree_int_cst_lt (pos, CASE_LOW (cs)))
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{
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int k;
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for (k = 0; k < info.phi_count; k++)
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{
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constructor_elt *elt;
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elt = VEC_quick_push (constructor_elt,
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info.constructors[k], NULL);
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elt->index = int_const_binop (MINUS_EXPR, pos,
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info.range_min, 0);
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elt->value = info.default_values[k];
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}
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pos = int_const_binop (PLUS_EXPR, pos, integer_one_node, 0);
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}
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gcc_assert (tree_int_cst_equal (pos, CASE_LOW (cs)));
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j = 0;
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if (CASE_HIGH (cs))
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high = CASE_HIGH (cs);
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else
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high = CASE_LOW (cs);
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for (gsi = gsi_start_phis (info.final_bb);
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!gsi_end_p (gsi); gsi_next (&gsi))
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{
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gimple phi = gsi_stmt (gsi);
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tree val = PHI_ARG_DEF_FROM_EDGE (phi, e);
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tree low = CASE_LOW (cs);
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pos = CASE_LOW (cs);
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do
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{
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constructor_elt *elt;
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elt = VEC_quick_push (constructor_elt,
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info.constructors[j], NULL);
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elt->index = int_const_binop (MINUS_EXPR, pos, info.range_min, 0);
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elt->value = val;
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pos = int_const_binop (PLUS_EXPR, pos, integer_one_node, 0);
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} while (!tree_int_cst_lt (high, pos)
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&& tree_int_cst_lt (low, pos));
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j++;
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}
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}
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}
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/* If all values in the constructor vector are the same, return the value.
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Otherwise return NULL_TREE. Not supposed to be called for empty
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vectors. */
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static tree
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constructor_contains_same_values_p (VEC (constructor_elt, gc) *vec)
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{
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int i, len = VEC_length (constructor_elt, vec);
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tree prev = NULL_TREE;
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for (i = 0; i < len; i++)
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{
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constructor_elt *elt = VEC_index (constructor_elt, vec, i);
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if (!prev)
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prev = elt->value;
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else if (!operand_equal_p (elt->value, prev, OEP_ONLY_CONST))
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return NULL_TREE;
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}
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return prev;
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}
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/* Create an appropriate array type and declaration and assemble a static array
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variable. Also create a load statement that initializes the variable in
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question with a value from the static array. SWTCH is the switch statement
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being converted, NUM is the index to arrays of constructors, default values
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and target SSA names for this particular array. ARR_INDEX_TYPE is the type
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of the index of the new array, PHI is the phi node of the final BB that
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corresponds to the value that will be loaded from the created array. TIDX
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is an ssa name of a temporary variable holding the index for loads from the
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new array. */
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static void
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build_one_array (gimple swtch, int num, tree arr_index_type, gimple phi,
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tree tidx)
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{
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tree name, cst;
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gimple load;
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gimple_stmt_iterator gsi = gsi_for_stmt (swtch);
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gcc_assert (info.default_values[num]);
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name = make_ssa_name (SSA_NAME_VAR (PHI_RESULT (phi)), NULL);
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info.target_inbound_names[num] = name;
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cst = constructor_contains_same_values_p (info.constructors[num]);
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if (cst)
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load = gimple_build_assign (name, cst);
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else
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{
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tree array_type, ctor, decl, value_type, fetch;
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value_type = TREE_TYPE (info.default_values[num]);
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array_type = build_array_type (value_type, arr_index_type);
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ctor = build_constructor (array_type, info.constructors[num]);
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TREE_CONSTANT (ctor) = true;
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decl = build_decl (VAR_DECL, NULL_TREE, array_type);
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TREE_STATIC (decl) = 1;
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DECL_INITIAL (decl) = ctor;
|
|
|
|
DECL_NAME (decl) = create_tmp_var_name ("CSWTCH");
|
|
DECL_ARTIFICIAL (decl) = 1;
|
|
TREE_CONSTANT (decl) = 1;
|
|
add_referenced_var (decl);
|
|
varpool_mark_needed_node (varpool_node (decl));
|
|
varpool_finalize_decl (decl);
|
|
|
|
fetch = build4 (ARRAY_REF, value_type, decl, tidx, NULL_TREE,
|
|
NULL_TREE);
|
|
load = gimple_build_assign (name, fetch);
|
|
}
|
|
|
|
SSA_NAME_DEF_STMT (name) = load;
|
|
gsi_insert_before (&gsi, load, GSI_SAME_STMT);
|
|
update_stmt (load);
|
|
info.arr_ref_last = load;
|
|
}
|
|
|
|
/* Builds and initializes static arrays initialized with values gathered from
|
|
the SWTCH switch statement. Also creates statements that load values from
|
|
them. */
|
|
|
|
static void
|
|
build_arrays (gimple swtch)
|
|
{
|
|
tree arr_index_type;
|
|
tree tidx, sub, tmp;
|
|
gimple stmt;
|
|
gimple_stmt_iterator gsi;
|
|
int i;
|
|
|
|
gsi = gsi_for_stmt (swtch);
|
|
|
|
arr_index_type = build_index_type (info.range_size);
|
|
tmp = create_tmp_var (arr_index_type, "csti");
|
|
add_referenced_var (tmp);
|
|
tidx = make_ssa_name (tmp, NULL);
|
|
sub = fold_build2 (MINUS_EXPR, TREE_TYPE (info.index_expr), info.index_expr,
|
|
fold_convert (TREE_TYPE (info.index_expr),
|
|
info.range_min));
|
|
sub = force_gimple_operand_gsi (&gsi, fold_convert (arr_index_type, sub),
|
|
false, NULL, true, GSI_SAME_STMT);
|
|
stmt = gimple_build_assign (tidx, sub);
|
|
SSA_NAME_DEF_STMT (tidx) = stmt;
|
|
|
|
gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
|
|
update_stmt (stmt);
|
|
info.arr_ref_first = stmt;
|
|
|
|
for (gsi = gsi_start_phis (info.final_bb), i = 0;
|
|
!gsi_end_p (gsi); gsi_next (&gsi), i++)
|
|
build_one_array (swtch, i, arr_index_type, gsi_stmt (gsi), tidx);
|
|
}
|
|
|
|
/* Generates and appropriately inserts loads of default values at the position
|
|
given by BSI. Returns the last inserted statement. */
|
|
|
|
static gimple
|
|
gen_def_assigns (gimple_stmt_iterator *gsi)
|
|
{
|
|
int i;
|
|
gimple assign = NULL;
|
|
|
|
for (i = 0; i < info.phi_count; i++)
|
|
{
|
|
tree name
|
|
= make_ssa_name (SSA_NAME_VAR (info.target_inbound_names[i]), NULL);
|
|
|
|
info.target_outbound_names[i] = name;
|
|
assign = gimple_build_assign (name, info.default_values[i]);
|
|
SSA_NAME_DEF_STMT (name) = assign;
|
|
gsi_insert_before (gsi, assign, GSI_SAME_STMT);
|
|
update_stmt (assign);
|
|
}
|
|
return assign;
|
|
}
|
|
|
|
/* Deletes the unused bbs and edges that now contain the switch statement and
|
|
its empty branch bbs. BBD is the now dead BB containing the original switch
|
|
statement, FINAL is the last BB of the converted switch statement (in terms
|
|
of succession). */
|
|
|
|
static void
|
|
prune_bbs (basic_block bbd, basic_block final)
|
|
{
|
|
edge_iterator ei;
|
|
edge e;
|
|
|
|
for (ei = ei_start (bbd->succs); (e = ei_safe_edge (ei)); )
|
|
{
|
|
basic_block bb;
|
|
bb = e->dest;
|
|
remove_edge (e);
|
|
if (bb != final)
|
|
delete_basic_block (bb);
|
|
}
|
|
delete_basic_block (bbd);
|
|
}
|
|
|
|
/* Add values to phi nodes in final_bb for the two new edges. E1F is the edge
|
|
from the basic block loading values from an array and E2F from the basic
|
|
block loading default values. BBF is the last switch basic block (see the
|
|
bbf description in the comment below). */
|
|
|
|
static void
|
|
fix_phi_nodes (edge e1f, edge e2f, basic_block bbf)
|
|
{
|
|
gimple_stmt_iterator gsi;
|
|
int i;
|
|
|
|
for (gsi = gsi_start_phis (bbf), i = 0;
|
|
!gsi_end_p (gsi); gsi_next (&gsi), i++)
|
|
{
|
|
gimple phi = gsi_stmt (gsi);
|
|
add_phi_arg (phi, info.target_inbound_names[i], e1f);
|
|
add_phi_arg (phi, info.target_outbound_names[i], e2f);
|
|
}
|
|
|
|
}
|
|
|
|
/* Creates a check whether the switch expression value actually falls into the
|
|
range given by all the cases. If it does not, the temporaries are loaded
|
|
with default values instead. SWTCH is the switch statement being converted.
|
|
|
|
bb0 is the bb with the switch statement, however, we'll end it with a
|
|
condition instead.
|
|
|
|
bb1 is the bb to be used when the range check went ok. It is derived from
|
|
the switch BB
|
|
|
|
bb2 is the bb taken when the expression evaluated outside of the range
|
|
covered by the created arrays. It is populated by loads of default
|
|
values.
|
|
|
|
bbF is a fall through for both bb1 and bb2 and contains exactly what
|
|
originally followed the switch statement.
|
|
|
|
bbD contains the switch statement (in the end). It is unreachable but we
|
|
still need to strip off its edges.
|
|
*/
|
|
|
|
static void
|
|
gen_inbound_check (gimple swtch)
|
|
{
|
|
tree label_decl1 = create_artificial_label ();
|
|
tree label_decl2 = create_artificial_label ();
|
|
tree label_decl3 = create_artificial_label ();
|
|
gimple label1, label2, label3;
|
|
|
|
tree utype;
|
|
tree tmp_u_1, tmp_u_2, tmp_u_var;
|
|
tree cast;
|
|
gimple cast_assign, minus_assign;
|
|
tree ulb, minus;
|
|
tree bound;
|
|
|
|
gimple cond_stmt;
|
|
|
|
gimple last_assign;
|
|
gimple_stmt_iterator gsi;
|
|
basic_block bb0, bb1, bb2, bbf, bbd;
|
|
edge e01, e02, e21, e1d, e1f, e2f;
|
|
|
|
gcc_assert (info.default_values);
|
|
bb0 = gimple_bb (swtch);
|
|
|
|
/* Make sure we do not generate arithmetics in a subrange. */
|
|
if (TREE_TYPE (TREE_TYPE (info.index_expr)))
|
|
utype = unsigned_type_for (TREE_TYPE (TREE_TYPE (info.index_expr)));
|
|
else
|
|
utype = unsigned_type_for (TREE_TYPE (info.index_expr));
|
|
|
|
/* (end of) block 0 */
|
|
gsi = gsi_for_stmt (info.arr_ref_first);
|
|
tmp_u_var = create_tmp_var (utype, "csui");
|
|
add_referenced_var (tmp_u_var);
|
|
tmp_u_1 = make_ssa_name (tmp_u_var, NULL);
|
|
|
|
cast = fold_convert (utype, info.index_expr);
|
|
cast_assign = gimple_build_assign (tmp_u_1, cast);
|
|
SSA_NAME_DEF_STMT (tmp_u_1) = cast_assign;
|
|
gsi_insert_before (&gsi, cast_assign, GSI_SAME_STMT);
|
|
update_stmt (cast_assign);
|
|
|
|
ulb = fold_convert (utype, info.range_min);
|
|
minus = fold_build2 (MINUS_EXPR, utype, tmp_u_1, ulb);
|
|
minus = force_gimple_operand_gsi (&gsi, minus, false, NULL, true,
|
|
GSI_SAME_STMT);
|
|
tmp_u_2 = make_ssa_name (tmp_u_var, NULL);
|
|
minus_assign = gimple_build_assign (tmp_u_2, minus);
|
|
SSA_NAME_DEF_STMT (tmp_u_2) = minus_assign;
|
|
gsi_insert_before (&gsi, minus_assign, GSI_SAME_STMT);
|
|
update_stmt (minus_assign);
|
|
|
|
bound = fold_convert (utype, info.range_size);
|
|
cond_stmt = gimple_build_cond (LE_EXPR, tmp_u_2, bound, NULL_TREE, NULL_TREE);
|
|
gsi_insert_before (&gsi, cond_stmt, GSI_SAME_STMT);
|
|
update_stmt (cond_stmt);
|
|
|
|
/* block 2 */
|
|
gsi = gsi_for_stmt (info.arr_ref_first);
|
|
label2 = gimple_build_label (label_decl2);
|
|
gsi_insert_before (&gsi, label2, GSI_SAME_STMT);
|
|
last_assign = gen_def_assigns (&gsi);
|
|
|
|
/* block 1 */
|
|
gsi = gsi_for_stmt (info.arr_ref_first);
|
|
label1 = gimple_build_label (label_decl1);
|
|
gsi_insert_before (&gsi, label1, GSI_SAME_STMT);
|
|
|
|
/* block F */
|
|
gsi = gsi_start_bb (info.final_bb);
|
|
label3 = gimple_build_label (label_decl3);
|
|
gsi_insert_before (&gsi, label3, GSI_SAME_STMT);
|
|
|
|
/* cfg fix */
|
|
e02 = split_block (bb0, cond_stmt);
|
|
bb2 = e02->dest;
|
|
|
|
e21 = split_block (bb2, last_assign);
|
|
bb1 = e21->dest;
|
|
remove_edge (e21);
|
|
|
|
e1d = split_block (bb1, info.arr_ref_last);
|
|
bbd = e1d->dest;
|
|
remove_edge (e1d);
|
|
|
|
/* flags and profiles of the edge for in-range values */
|
|
e01 = make_edge (bb0, bb1, EDGE_TRUE_VALUE);
|
|
e01->probability = REG_BR_PROB_BASE - info.default_prob;
|
|
e01->count = info.other_count;
|
|
|
|
/* flags and profiles of the edge taking care of out-of-range values */
|
|
e02->flags &= ~EDGE_FALLTHRU;
|
|
e02->flags |= EDGE_FALSE_VALUE;
|
|
e02->probability = info.default_prob;
|
|
e02->count = info.default_count;
|
|
|
|
bbf = info.final_bb;
|
|
|
|
e1f = make_edge (bb1, bbf, EDGE_FALLTHRU);
|
|
e1f->probability = REG_BR_PROB_BASE;
|
|
e1f->count = info.other_count;
|
|
|
|
e2f = make_edge (bb2, bbf, EDGE_FALLTHRU);
|
|
e2f->probability = REG_BR_PROB_BASE;
|
|
e2f->count = info.default_count;
|
|
|
|
/* frequencies of the new BBs */
|
|
bb1->frequency = EDGE_FREQUENCY (e01);
|
|
bb2->frequency = EDGE_FREQUENCY (e02);
|
|
bbf->frequency = EDGE_FREQUENCY (e1f) + EDGE_FREQUENCY (e2f);
|
|
|
|
prune_bbs (bbd, info.final_bb); /* To keep calc_dfs_tree() in dominance.c
|
|
happy. */
|
|
|
|
fix_phi_nodes (e1f, e2f, bbf);
|
|
|
|
free_dominance_info (CDI_DOMINATORS);
|
|
free_dominance_info (CDI_POST_DOMINATORS);
|
|
}
|
|
|
|
/* The following function is invoked on every switch statement (the current one
|
|
is given in SWTCH) and runs the individual phases of switch conversion on it
|
|
one after another until one fails or the conversion is completed. */
|
|
|
|
static bool
|
|
process_switch (gimple swtch)
|
|
{
|
|
unsigned int i, branch_num = gimple_switch_num_labels (swtch);
|
|
tree index_type;
|
|
|
|
/* Operand 2 is either NULL_TREE or a vector of cases (stmt.c). */
|
|
if (branch_num < 2)
|
|
{
|
|
info.reason = "switch has no labels\n";
|
|
return false;
|
|
}
|
|
|
|
info.final_bb = NULL;
|
|
info.switch_bb = gimple_bb (swtch);
|
|
info.index_expr = gimple_switch_index (swtch);
|
|
index_type = TREE_TYPE (info.index_expr);
|
|
info.arr_ref_first = NULL;
|
|
info.arr_ref_last = NULL;
|
|
info.default_prob = 0;
|
|
info.default_count = 0;
|
|
info.other_count = 0;
|
|
|
|
/* An ERROR_MARK occurs for various reasons including invalid data type.
|
|
(comment from stmt.c) */
|
|
if (index_type == error_mark_node)
|
|
{
|
|
info.reason = "index error.\n";
|
|
return false;
|
|
}
|
|
|
|
/* Check the case label values are within reasonable range: */
|
|
if (!check_range (swtch))
|
|
return false;
|
|
|
|
/* For all the cases, see whether they are empty, the assignments they
|
|
represent constant and so on... */
|
|
for (i = 0; i < branch_num; i++)
|
|
if (!check_process_case (gimple_switch_label (swtch, i)))
|
|
{
|
|
if (dump_file)
|
|
fprintf (dump_file, "Processing of case %i failed\n", i);
|
|
return false;
|
|
}
|
|
|
|
if (!check_final_bb ())
|
|
return false;
|
|
|
|
/* At this point all checks have passed and we can proceed with the
|
|
transformation. */
|
|
|
|
create_temp_arrays ();
|
|
gather_default_values (gimple_switch_label (swtch, 0));
|
|
build_constructors (swtch);
|
|
|
|
build_arrays (swtch); /* Build the static arrays and assignments. */
|
|
gen_inbound_check (swtch); /* Build the bounds check. */
|
|
|
|
/* Cleanup: */
|
|
free_temp_arrays ();
|
|
return true;
|
|
}
|
|
|
|
/* The main function of the pass scans statements for switches and invokes
|
|
process_switch on them. */
|
|
|
|
static unsigned int
|
|
do_switchconv (void)
|
|
{
|
|
basic_block bb;
|
|
|
|
FOR_EACH_BB (bb)
|
|
{
|
|
gimple stmt = last_stmt (bb);
|
|
if (stmt && gimple_code (stmt) == GIMPLE_SWITCH)
|
|
{
|
|
if (dump_file)
|
|
{
|
|
expanded_location loc = expand_location (gimple_location (stmt));
|
|
|
|
fprintf (dump_file, "beginning to process the following "
|
|
"SWITCH statement (%s:%d) : ------- \n",
|
|
loc.file, loc.line);
|
|
print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM);
|
|
fprintf (dump_file, "\n");
|
|
}
|
|
|
|
info.reason = NULL;
|
|
if (process_switch (stmt))
|
|
{
|
|
if (dump_file)
|
|
{
|
|
fprintf (dump_file, "Switch converted\n");
|
|
fprintf (dump_file, "--------------------------------\n");
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (dump_file)
|
|
{
|
|
gcc_assert (info.reason);
|
|
fprintf (dump_file, "Bailing out - ");
|
|
fprintf (dump_file, info.reason);
|
|
fprintf (dump_file, "--------------------------------\n");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* The pass gate. */
|
|
|
|
static bool
|
|
switchconv_gate (void)
|
|
{
|
|
return flag_tree_switch_conversion != 0;
|
|
}
|
|
|
|
struct gimple_opt_pass pass_convert_switch =
|
|
{
|
|
{
|
|
GIMPLE_PASS,
|
|
"switchconv", /* name */
|
|
switchconv_gate, /* gate */
|
|
do_switchconv, /* execute */
|
|
NULL, /* sub */
|
|
NULL, /* next */
|
|
0, /* static_pass_number */
|
|
TV_TREE_SWITCH_CONVERSION, /* tv_id */
|
|
PROP_cfg | PROP_ssa, /* properties_required */
|
|
0, /* properties_provided */
|
|
0, /* properties_destroyed */
|
|
0, /* todo_flags_start */
|
|
TODO_update_ssa | TODO_dump_func
|
|
| TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */
|
|
}
|
|
};
|