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4496 lines
134 KiB
C
4496 lines
134 KiB
C
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/* Data references and dependences detectors.
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Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
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Contributed by Sebastian Pop <pop@cri.ensmp.fr>
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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 under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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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 COPYING. 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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/* This pass walks a given loop structure searching for array
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references. The information about the array accesses is recorded
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in DATA_REFERENCE structures.
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The basic test for determining the dependences is:
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given two access functions chrec1 and chrec2 to a same array, and
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x and y two vectors from the iteration domain, the same element of
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the array is accessed twice at iterations x and y if and only if:
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| chrec1 (x) == chrec2 (y).
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The goals of this analysis are:
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- to determine the independence: the relation between two
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independent accesses is qualified with the chrec_known (this
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information allows a loop parallelization),
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- when two data references access the same data, to qualify the
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dependence relation with classic dependence representations:
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- distance vectors
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- direction vectors
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- loop carried level dependence
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- polyhedron dependence
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or with the chains of recurrences based representation,
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- to define a knowledge base for storing the data dependence
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information,
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- to define an interface to access this data.
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Definitions:
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- subscript: given two array accesses a subscript is the tuple
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composed of the access functions for a given dimension. Example:
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Given A[f1][f2][f3] and B[g1][g2][g3], there are three subscripts:
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(f1, g1), (f2, g2), (f3, g3).
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- Diophantine equation: an equation whose coefficients and
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solutions are integer constants, for example the equation
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| 3*x + 2*y = 1
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has an integer solution x = 1 and y = -1.
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References:
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- "Advanced Compilation for High Performance Computing" by Randy
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Allen and Ken Kennedy.
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http://citeseer.ist.psu.edu/goff91practical.html
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- "Loop Transformations for Restructuring Compilers - The Foundations"
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by Utpal Banerjee.
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*/
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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 "ggc.h"
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#include "tree.h"
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/* These RTL headers are needed for basic-block.h. */
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#include "rtl.h"
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#include "basic-block.h"
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#include "diagnostic.h"
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#include "tree-flow.h"
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#include "tree-dump.h"
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#include "timevar.h"
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#include "cfgloop.h"
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#include "tree-chrec.h"
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#include "tree-data-ref.h"
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#include "tree-scalar-evolution.h"
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#include "tree-pass.h"
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static struct datadep_stats
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{
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int num_dependence_tests;
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int num_dependence_dependent;
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int num_dependence_independent;
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int num_dependence_undetermined;
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int num_subscript_tests;
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int num_subscript_undetermined;
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int num_same_subscript_function;
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int num_ziv;
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int num_ziv_independent;
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int num_ziv_dependent;
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int num_ziv_unimplemented;
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int num_siv;
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int num_siv_independent;
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int num_siv_dependent;
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int num_siv_unimplemented;
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int num_miv;
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int num_miv_independent;
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int num_miv_dependent;
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int num_miv_unimplemented;
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} dependence_stats;
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static tree object_analysis (tree, tree, bool, struct data_reference **,
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tree *, tree *, tree *, tree *, tree *,
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struct ptr_info_def **, subvar_t *);
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static struct data_reference * init_data_ref (tree, tree, tree, tree, bool,
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tree, tree, tree, tree, tree,
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struct ptr_info_def *,
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enum data_ref_type);
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static bool subscript_dependence_tester_1 (struct data_dependence_relation *,
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struct data_reference *,
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struct data_reference *);
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/* Determine if PTR and DECL may alias, the result is put in ALIASED.
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Return FALSE if there is no symbol memory tag for PTR. */
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static bool
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ptr_decl_may_alias_p (tree ptr, tree decl,
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struct data_reference *ptr_dr,
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bool *aliased)
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{
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tree tag = NULL_TREE;
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struct ptr_info_def *pi = DR_PTR_INFO (ptr_dr);
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gcc_assert (TREE_CODE (ptr) == SSA_NAME && DECL_P (decl));
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if (pi)
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tag = pi->name_mem_tag;
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if (!tag)
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tag = get_var_ann (SSA_NAME_VAR (ptr))->symbol_mem_tag;
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if (!tag)
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tag = DR_MEMTAG (ptr_dr);
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if (!tag)
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return false;
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*aliased = is_aliased_with (tag, decl);
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return true;
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}
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/* Determine if two pointers may alias, the result is put in ALIASED.
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Return FALSE if there is no symbol memory tag for one of the pointers. */
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static bool
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ptr_ptr_may_alias_p (tree ptr_a, tree ptr_b,
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struct data_reference *dra,
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struct data_reference *drb,
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bool *aliased)
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{
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tree tag_a = NULL_TREE, tag_b = NULL_TREE;
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struct ptr_info_def *pi_a = DR_PTR_INFO (dra);
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struct ptr_info_def *pi_b = DR_PTR_INFO (drb);
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if (pi_a && pi_a->name_mem_tag && pi_b && pi_b->name_mem_tag)
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{
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tag_a = pi_a->name_mem_tag;
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tag_b = pi_b->name_mem_tag;
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}
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else
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{
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tag_a = get_var_ann (SSA_NAME_VAR (ptr_a))->symbol_mem_tag;
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if (!tag_a)
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tag_a = DR_MEMTAG (dra);
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if (!tag_a)
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return false;
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tag_b = get_var_ann (SSA_NAME_VAR (ptr_b))->symbol_mem_tag;
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if (!tag_b)
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tag_b = DR_MEMTAG (drb);
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if (!tag_b)
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return false;
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}
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if (tag_a == tag_b)
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*aliased = true;
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else
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*aliased = may_aliases_intersect (tag_a, tag_b);
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return true;
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}
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/* Determine if BASE_A and BASE_B may alias, the result is put in ALIASED.
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Return FALSE if there is no symbol memory tag for one of the symbols. */
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static bool
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may_alias_p (tree base_a, tree base_b,
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struct data_reference *dra,
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struct data_reference *drb,
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bool *aliased)
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{
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if (TREE_CODE (base_a) == ADDR_EXPR || TREE_CODE (base_b) == ADDR_EXPR)
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{
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if (TREE_CODE (base_a) == ADDR_EXPR && TREE_CODE (base_b) == ADDR_EXPR)
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{
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*aliased = (TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0));
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return true;
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}
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if (TREE_CODE (base_a) == ADDR_EXPR)
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return ptr_decl_may_alias_p (base_b, TREE_OPERAND (base_a, 0), drb,
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aliased);
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else
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return ptr_decl_may_alias_p (base_a, TREE_OPERAND (base_b, 0), dra,
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aliased);
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}
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return ptr_ptr_may_alias_p (base_a, base_b, dra, drb, aliased);
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}
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/* Determine if a pointer (BASE_A) and a record/union access (BASE_B)
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are not aliased. Return TRUE if they differ. */
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static bool
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record_ptr_differ_p (struct data_reference *dra,
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struct data_reference *drb)
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{
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bool aliased;
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tree base_a = DR_BASE_OBJECT (dra);
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tree base_b = DR_BASE_OBJECT (drb);
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if (TREE_CODE (base_b) != COMPONENT_REF)
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return false;
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/* Peel COMPONENT_REFs to get to the base. Do not peel INDIRECT_REFs.
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For a.b.c.d[i] we will get a, and for a.b->c.d[i] we will get a.b.
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Probably will be unnecessary with struct alias analysis. */
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while (TREE_CODE (base_b) == COMPONENT_REF)
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base_b = TREE_OPERAND (base_b, 0);
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/* Compare a record/union access (b.c[i] or p->c[i]) and a pointer
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((*q)[i]). */
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if (TREE_CODE (base_a) == INDIRECT_REF
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&& ((TREE_CODE (base_b) == VAR_DECL
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&& (ptr_decl_may_alias_p (TREE_OPERAND (base_a, 0), base_b, dra,
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&aliased)
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&& !aliased))
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|| (TREE_CODE (base_b) == INDIRECT_REF
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&& (ptr_ptr_may_alias_p (TREE_OPERAND (base_a, 0),
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TREE_OPERAND (base_b, 0), dra, drb,
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&aliased)
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&& !aliased))))
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return true;
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else
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return false;
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}
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/* Determine if two record/union accesses are aliased. Return TRUE if they
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differ. */
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static bool
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record_record_differ_p (struct data_reference *dra,
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struct data_reference *drb)
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{
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bool aliased;
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tree base_a = DR_BASE_OBJECT (dra);
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tree base_b = DR_BASE_OBJECT (drb);
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if (TREE_CODE (base_b) != COMPONENT_REF
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|| TREE_CODE (base_a) != COMPONENT_REF)
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return false;
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/* Peel COMPONENT_REFs to get to the base. Do not peel INDIRECT_REFs.
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For a.b.c.d[i] we will get a, and for a.b->c.d[i] we will get a.b.
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Probably will be unnecessary with struct alias analysis. */
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while (TREE_CODE (base_b) == COMPONENT_REF)
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base_b = TREE_OPERAND (base_b, 0);
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while (TREE_CODE (base_a) == COMPONENT_REF)
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base_a = TREE_OPERAND (base_a, 0);
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if (TREE_CODE (base_a) == INDIRECT_REF
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&& TREE_CODE (base_b) == INDIRECT_REF
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&& ptr_ptr_may_alias_p (TREE_OPERAND (base_a, 0),
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TREE_OPERAND (base_b, 0),
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dra, drb, &aliased)
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&& !aliased)
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return true;
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else
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return false;
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}
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/* Determine if an array access (BASE_A) and a record/union access (BASE_B)
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are not aliased. Return TRUE if they differ. */
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static bool
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record_array_differ_p (struct data_reference *dra,
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struct data_reference *drb)
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{
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bool aliased;
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tree base_a = DR_BASE_OBJECT (dra);
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tree base_b = DR_BASE_OBJECT (drb);
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if (TREE_CODE (base_b) != COMPONENT_REF)
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return false;
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/* Peel COMPONENT_REFs to get to the base. Do not peel INDIRECT_REFs.
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For a.b.c.d[i] we will get a, and for a.b->c.d[i] we will get a.b.
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Probably will be unnecessary with struct alias analysis. */
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while (TREE_CODE (base_b) == COMPONENT_REF)
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base_b = TREE_OPERAND (base_b, 0);
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/* Compare a record/union access (b.c[i] or p->c[i]) and an array access
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(a[i]). In case of p->c[i] use alias analysis to verify that p is not
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pointing to a. */
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if (TREE_CODE (base_a) == VAR_DECL
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&& (TREE_CODE (base_b) == VAR_DECL
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|| (TREE_CODE (base_b) == INDIRECT_REF
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&& (ptr_decl_may_alias_p (TREE_OPERAND (base_b, 0), base_a, drb,
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&aliased)
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&& !aliased))))
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return true;
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else
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return false;
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}
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/* Determine if an array access (BASE_A) and a pointer (BASE_B)
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are not aliased. Return TRUE if they differ. */
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static bool
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array_ptr_differ_p (tree base_a, tree base_b,
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struct data_reference *drb)
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{
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bool aliased;
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/* In case one of the bases is a pointer (a[i] and (*p)[i]), we check with the
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help of alias analysis that p is not pointing to a. */
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if (TREE_CODE (base_a) == VAR_DECL && TREE_CODE (base_b) == INDIRECT_REF
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&& (ptr_decl_may_alias_p (TREE_OPERAND (base_b, 0), base_a, drb, &aliased)
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&& !aliased))
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return true;
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else
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return false;
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}
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/* This is the simplest data dependence test: determines whether the
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data references A and B access the same array/region. Returns
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false when the property is not computable at compile time.
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Otherwise return true, and DIFFER_P will record the result. This
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utility will not be necessary when alias_sets_conflict_p will be
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less conservative. */
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static bool
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base_object_differ_p (struct data_reference *a,
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struct data_reference *b,
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bool *differ_p)
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{
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tree base_a = DR_BASE_OBJECT (a);
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tree base_b = DR_BASE_OBJECT (b);
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bool aliased;
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if (!base_a || !base_b)
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return false;
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|
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/* Determine if same base. Example: for the array accesses
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a[i], b[i] or pointer accesses *a, *b, bases are a, b. */
|
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if (base_a == base_b)
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{
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*differ_p = false;
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return true;
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}
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|
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/* For pointer based accesses, (*p)[i], (*q)[j], the bases are (*p)
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and (*q) */
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if (TREE_CODE (base_a) == INDIRECT_REF && TREE_CODE (base_b) == INDIRECT_REF
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&& TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0))
|
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{
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*differ_p = false;
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return true;
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}
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||
|
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/* Record/union based accesses - s.a[i], t.b[j]. bases are s.a,t.b. */
|
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if (TREE_CODE (base_a) == COMPONENT_REF && TREE_CODE (base_b) == COMPONENT_REF
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&& TREE_OPERAND (base_a, 0) == TREE_OPERAND (base_b, 0)
|
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&& TREE_OPERAND (base_a, 1) == TREE_OPERAND (base_b, 1))
|
||
{
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*differ_p = false;
|
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return true;
|
||
}
|
||
|
||
|
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/* Determine if different bases. */
|
||
|
||
/* At this point we know that base_a != base_b. However, pointer
|
||
accesses of the form x=(*p) and y=(*q), whose bases are p and q,
|
||
may still be pointing to the same base. In SSAed GIMPLE p and q will
|
||
be SSA_NAMES in this case. Therefore, here we check if they are
|
||
really two different declarations. */
|
||
if (TREE_CODE (base_a) == VAR_DECL && TREE_CODE (base_b) == VAR_DECL)
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* In case one of the bases is a pointer (a[i] and (*p)[i]), we check with the
|
||
help of alias analysis that p is not pointing to a. */
|
||
if (array_ptr_differ_p (base_a, base_b, b)
|
||
|| array_ptr_differ_p (base_b, base_a, a))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* If the bases are pointers ((*q)[i] and (*p)[i]), we check with the
|
||
help of alias analysis they don't point to the same bases. */
|
||
if (TREE_CODE (base_a) == INDIRECT_REF && TREE_CODE (base_b) == INDIRECT_REF
|
||
&& (may_alias_p (TREE_OPERAND (base_a, 0), TREE_OPERAND (base_b, 0), a, b,
|
||
&aliased)
|
||
&& !aliased))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* Compare two record/union bases s.a and t.b: s != t or (a != b and
|
||
s and t are not unions). */
|
||
if (TREE_CODE (base_a) == COMPONENT_REF && TREE_CODE (base_b) == COMPONENT_REF
|
||
&& ((TREE_CODE (TREE_OPERAND (base_a, 0)) == VAR_DECL
|
||
&& TREE_CODE (TREE_OPERAND (base_b, 0)) == VAR_DECL
|
||
&& TREE_OPERAND (base_a, 0) != TREE_OPERAND (base_b, 0))
|
||
|| (TREE_CODE (TREE_TYPE (TREE_OPERAND (base_a, 0))) == RECORD_TYPE
|
||
&& TREE_CODE (TREE_TYPE (TREE_OPERAND (base_b, 0))) == RECORD_TYPE
|
||
&& TREE_OPERAND (base_a, 1) != TREE_OPERAND (base_b, 1))))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* Compare a record/union access (b.c[i] or p->c[i]) and a pointer
|
||
((*q)[i]). */
|
||
if (record_ptr_differ_p (a, b) || record_ptr_differ_p (b, a))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* Compare a record/union access (b.c[i] or p->c[i]) and an array access
|
||
(a[i]). In case of p->c[i] use alias analysis to verify that p is not
|
||
pointing to a. */
|
||
if (record_array_differ_p (a, b) || record_array_differ_p (b, a))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* Compare two record/union accesses (b.c[i] or p->c[i]). */
|
||
if (record_record_differ_p (a, b))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
return false;
|
||
}
|
||
|
||
/* Function base_addr_differ_p.
|
||
|
||
This is the simplest data dependence test: determines whether the
|
||
data references DRA and DRB access the same array/region. Returns
|
||
false when the property is not computable at compile time.
|
||
Otherwise return true, and DIFFER_P will record the result.
|
||
|
||
The algorithm:
|
||
1. if (both DRA and DRB are represented as arrays)
|
||
compare DRA.BASE_OBJECT and DRB.BASE_OBJECT
|
||
2. else if (both DRA and DRB are represented as pointers)
|
||
try to prove that DRA.FIRST_LOCATION == DRB.FIRST_LOCATION
|
||
3. else if (DRA and DRB are represented differently or 2. fails)
|
||
only try to prove that the bases are surely different
|
||
*/
|
||
|
||
static bool
|
||
base_addr_differ_p (struct data_reference *dra,
|
||
struct data_reference *drb,
|
||
bool *differ_p)
|
||
{
|
||
tree addr_a = DR_BASE_ADDRESS (dra);
|
||
tree addr_b = DR_BASE_ADDRESS (drb);
|
||
tree type_a, type_b;
|
||
bool aliased;
|
||
|
||
if (!addr_a || !addr_b)
|
||
return false;
|
||
|
||
type_a = TREE_TYPE (addr_a);
|
||
type_b = TREE_TYPE (addr_b);
|
||
|
||
gcc_assert (POINTER_TYPE_P (type_a) && POINTER_TYPE_P (type_b));
|
||
|
||
/* 1. if (both DRA and DRB are represented as arrays)
|
||
compare DRA.BASE_OBJECT and DRB.BASE_OBJECT. */
|
||
if (DR_TYPE (dra) == ARRAY_REF_TYPE && DR_TYPE (drb) == ARRAY_REF_TYPE)
|
||
return base_object_differ_p (dra, drb, differ_p);
|
||
|
||
/* 2. else if (both DRA and DRB are represented as pointers)
|
||
try to prove that DRA.FIRST_LOCATION == DRB.FIRST_LOCATION. */
|
||
/* If base addresses are the same, we check the offsets, since the access of
|
||
the data-ref is described by {base addr + offset} and its access function,
|
||
i.e., in order to decide whether the bases of data-refs are the same we
|
||
compare both base addresses and offsets. */
|
||
if (DR_TYPE (dra) == POINTER_REF_TYPE && DR_TYPE (drb) == POINTER_REF_TYPE
|
||
&& (addr_a == addr_b
|
||
|| (TREE_CODE (addr_a) == ADDR_EXPR && TREE_CODE (addr_b) == ADDR_EXPR
|
||
&& TREE_OPERAND (addr_a, 0) == TREE_OPERAND (addr_b, 0))))
|
||
{
|
||
/* Compare offsets. */
|
||
tree offset_a = DR_OFFSET (dra);
|
||
tree offset_b = DR_OFFSET (drb);
|
||
|
||
STRIP_NOPS (offset_a);
|
||
STRIP_NOPS (offset_b);
|
||
|
||
/* FORNOW: we only compare offsets that are MULT_EXPR, i.e., we don't handle
|
||
PLUS_EXPR. */
|
||
if (offset_a == offset_b
|
||
|| (TREE_CODE (offset_a) == MULT_EXPR
|
||
&& TREE_CODE (offset_b) == MULT_EXPR
|
||
&& TREE_OPERAND (offset_a, 0) == TREE_OPERAND (offset_b, 0)
|
||
&& TREE_OPERAND (offset_a, 1) == TREE_OPERAND (offset_b, 1)))
|
||
{
|
||
*differ_p = false;
|
||
return true;
|
||
}
|
||
}
|
||
|
||
/* 3. else if (DRA and DRB are represented differently or 2. fails)
|
||
only try to prove that the bases are surely different. */
|
||
|
||
/* Apply alias analysis. */
|
||
if (may_alias_p (addr_a, addr_b, dra, drb, &aliased) && !aliased)
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
|
||
/* An instruction writing through a restricted pointer is "independent" of any
|
||
instruction reading or writing through a different pointer, in the same
|
||
block/scope. */
|
||
else if ((TYPE_RESTRICT (type_a) && !DR_IS_READ (dra))
|
||
|| (TYPE_RESTRICT (type_b) && !DR_IS_READ (drb)))
|
||
{
|
||
*differ_p = true;
|
||
return true;
|
||
}
|
||
return false;
|
||
}
|
||
|
||
/* Returns true iff A divides B. */
|
||
|
||
static inline bool
|
||
tree_fold_divides_p (tree a,
|
||
tree b)
|
||
{
|
||
/* Determines whether (A == gcd (A, B)). */
|
||
return tree_int_cst_equal (a, tree_fold_gcd (a, b));
|
||
}
|
||
|
||
/* Returns true iff A divides B. */
|
||
|
||
static inline bool
|
||
int_divides_p (int a, int b)
|
||
{
|
||
return ((b % a) == 0);
|
||
}
|
||
|
||
|
||
|
||
/* Dump into FILE all the data references from DATAREFS. */
|
||
|
||
void
|
||
dump_data_references (FILE *file, VEC (data_reference_p, heap) *datarefs)
|
||
{
|
||
unsigned int i;
|
||
struct data_reference *dr;
|
||
|
||
for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
|
||
dump_data_reference (file, dr);
|
||
}
|
||
|
||
/* Dump into FILE all the dependence relations from DDRS. */
|
||
|
||
void
|
||
dump_data_dependence_relations (FILE *file,
|
||
VEC (ddr_p, heap) *ddrs)
|
||
{
|
||
unsigned int i;
|
||
struct data_dependence_relation *ddr;
|
||
|
||
for (i = 0; VEC_iterate (ddr_p, ddrs, i, ddr); i++)
|
||
dump_data_dependence_relation (file, ddr);
|
||
}
|
||
|
||
/* Dump function for a DATA_REFERENCE structure. */
|
||
|
||
void
|
||
dump_data_reference (FILE *outf,
|
||
struct data_reference *dr)
|
||
{
|
||
unsigned int i;
|
||
|
||
fprintf (outf, "(Data Ref: \n stmt: ");
|
||
print_generic_stmt (outf, DR_STMT (dr), 0);
|
||
fprintf (outf, " ref: ");
|
||
print_generic_stmt (outf, DR_REF (dr), 0);
|
||
fprintf (outf, " base_object: ");
|
||
print_generic_stmt (outf, DR_BASE_OBJECT (dr), 0);
|
||
|
||
for (i = 0; i < DR_NUM_DIMENSIONS (dr); i++)
|
||
{
|
||
fprintf (outf, " Access function %d: ", i);
|
||
print_generic_stmt (outf, DR_ACCESS_FN (dr, i), 0);
|
||
}
|
||
fprintf (outf, ")\n");
|
||
}
|
||
|
||
/* Dump function for a SUBSCRIPT structure. */
|
||
|
||
void
|
||
dump_subscript (FILE *outf, struct subscript *subscript)
|
||
{
|
||
tree chrec = SUB_CONFLICTS_IN_A (subscript);
|
||
|
||
fprintf (outf, "\n (subscript \n");
|
||
fprintf (outf, " iterations_that_access_an_element_twice_in_A: ");
|
||
print_generic_stmt (outf, chrec, 0);
|
||
if (chrec == chrec_known)
|
||
fprintf (outf, " (no dependence)\n");
|
||
else if (chrec_contains_undetermined (chrec))
|
||
fprintf (outf, " (don't know)\n");
|
||
else
|
||
{
|
||
tree last_iteration = SUB_LAST_CONFLICT (subscript);
|
||
fprintf (outf, " last_conflict: ");
|
||
print_generic_stmt (outf, last_iteration, 0);
|
||
}
|
||
|
||
chrec = SUB_CONFLICTS_IN_B (subscript);
|
||
fprintf (outf, " iterations_that_access_an_element_twice_in_B: ");
|
||
print_generic_stmt (outf, chrec, 0);
|
||
if (chrec == chrec_known)
|
||
fprintf (outf, " (no dependence)\n");
|
||
else if (chrec_contains_undetermined (chrec))
|
||
fprintf (outf, " (don't know)\n");
|
||
else
|
||
{
|
||
tree last_iteration = SUB_LAST_CONFLICT (subscript);
|
||
fprintf (outf, " last_conflict: ");
|
||
print_generic_stmt (outf, last_iteration, 0);
|
||
}
|
||
|
||
fprintf (outf, " (Subscript distance: ");
|
||
print_generic_stmt (outf, SUB_DISTANCE (subscript), 0);
|
||
fprintf (outf, " )\n");
|
||
fprintf (outf, " )\n");
|
||
}
|
||
|
||
/* Print the classic direction vector DIRV to OUTF. */
|
||
|
||
void
|
||
print_direction_vector (FILE *outf,
|
||
lambda_vector dirv,
|
||
int length)
|
||
{
|
||
int eq;
|
||
|
||
for (eq = 0; eq < length; eq++)
|
||
{
|
||
enum data_dependence_direction dir = dirv[eq];
|
||
|
||
switch (dir)
|
||
{
|
||
case dir_positive:
|
||
fprintf (outf, " +");
|
||
break;
|
||
case dir_negative:
|
||
fprintf (outf, " -");
|
||
break;
|
||
case dir_equal:
|
||
fprintf (outf, " =");
|
||
break;
|
||
case dir_positive_or_equal:
|
||
fprintf (outf, " +=");
|
||
break;
|
||
case dir_positive_or_negative:
|
||
fprintf (outf, " +-");
|
||
break;
|
||
case dir_negative_or_equal:
|
||
fprintf (outf, " -=");
|
||
break;
|
||
case dir_star:
|
||
fprintf (outf, " *");
|
||
break;
|
||
default:
|
||
fprintf (outf, "indep");
|
||
break;
|
||
}
|
||
}
|
||
fprintf (outf, "\n");
|
||
}
|
||
|
||
/* Print a vector of direction vectors. */
|
||
|
||
void
|
||
print_dir_vectors (FILE *outf, VEC (lambda_vector, heap) *dir_vects,
|
||
int length)
|
||
{
|
||
unsigned j;
|
||
lambda_vector v;
|
||
|
||
for (j = 0; VEC_iterate (lambda_vector, dir_vects, j, v); j++)
|
||
print_direction_vector (outf, v, length);
|
||
}
|
||
|
||
/* Print a vector of distance vectors. */
|
||
|
||
void
|
||
print_dist_vectors (FILE *outf, VEC (lambda_vector, heap) *dist_vects,
|
||
int length)
|
||
{
|
||
unsigned j;
|
||
lambda_vector v;
|
||
|
||
for (j = 0; VEC_iterate (lambda_vector, dist_vects, j, v); j++)
|
||
print_lambda_vector (outf, v, length);
|
||
}
|
||
|
||
/* Debug version. */
|
||
|
||
void
|
||
debug_data_dependence_relation (struct data_dependence_relation *ddr)
|
||
{
|
||
dump_data_dependence_relation (stderr, ddr);
|
||
}
|
||
|
||
/* Dump function for a DATA_DEPENDENCE_RELATION structure. */
|
||
|
||
void
|
||
dump_data_dependence_relation (FILE *outf,
|
||
struct data_dependence_relation *ddr)
|
||
{
|
||
struct data_reference *dra, *drb;
|
||
|
||
dra = DDR_A (ddr);
|
||
drb = DDR_B (ddr);
|
||
fprintf (outf, "(Data Dep: \n");
|
||
if (DDR_ARE_DEPENDENT (ddr) == chrec_dont_know)
|
||
fprintf (outf, " (don't know)\n");
|
||
|
||
else if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
|
||
fprintf (outf, " (no dependence)\n");
|
||
|
||
else if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
|
||
{
|
||
unsigned int i;
|
||
struct loop *loopi;
|
||
|
||
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
|
||
{
|
||
fprintf (outf, " access_fn_A: ");
|
||
print_generic_stmt (outf, DR_ACCESS_FN (dra, i), 0);
|
||
fprintf (outf, " access_fn_B: ");
|
||
print_generic_stmt (outf, DR_ACCESS_FN (drb, i), 0);
|
||
dump_subscript (outf, DDR_SUBSCRIPT (ddr, i));
|
||
}
|
||
|
||
fprintf (outf, " loop nest: (");
|
||
for (i = 0; VEC_iterate (loop_p, DDR_LOOP_NEST (ddr), i, loopi); i++)
|
||
fprintf (outf, "%d ", loopi->num);
|
||
fprintf (outf, ")\n");
|
||
|
||
for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++)
|
||
{
|
||
fprintf (outf, " distance_vector: ");
|
||
print_lambda_vector (outf, DDR_DIST_VECT (ddr, i),
|
||
DDR_NB_LOOPS (ddr));
|
||
}
|
||
|
||
for (i = 0; i < DDR_NUM_DIR_VECTS (ddr); i++)
|
||
{
|
||
fprintf (outf, " direction_vector: ");
|
||
print_direction_vector (outf, DDR_DIR_VECT (ddr, i),
|
||
DDR_NB_LOOPS (ddr));
|
||
}
|
||
}
|
||
|
||
fprintf (outf, ")\n");
|
||
}
|
||
|
||
/* Dump function for a DATA_DEPENDENCE_DIRECTION structure. */
|
||
|
||
void
|
||
dump_data_dependence_direction (FILE *file,
|
||
enum data_dependence_direction dir)
|
||
{
|
||
switch (dir)
|
||
{
|
||
case dir_positive:
|
||
fprintf (file, "+");
|
||
break;
|
||
|
||
case dir_negative:
|
||
fprintf (file, "-");
|
||
break;
|
||
|
||
case dir_equal:
|
||
fprintf (file, "=");
|
||
break;
|
||
|
||
case dir_positive_or_negative:
|
||
fprintf (file, "+-");
|
||
break;
|
||
|
||
case dir_positive_or_equal:
|
||
fprintf (file, "+=");
|
||
break;
|
||
|
||
case dir_negative_or_equal:
|
||
fprintf (file, "-=");
|
||
break;
|
||
|
||
case dir_star:
|
||
fprintf (file, "*");
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
}
|
||
|
||
/* Dumps the distance and direction vectors in FILE. DDRS contains
|
||
the dependence relations, and VECT_SIZE is the size of the
|
||
dependence vectors, or in other words the number of loops in the
|
||
considered nest. */
|
||
|
||
void
|
||
dump_dist_dir_vectors (FILE *file, VEC (ddr_p, heap) *ddrs)
|
||
{
|
||
unsigned int i, j;
|
||
struct data_dependence_relation *ddr;
|
||
lambda_vector v;
|
||
|
||
for (i = 0; VEC_iterate (ddr_p, ddrs, i, ddr); i++)
|
||
if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE && DDR_AFFINE_P (ddr))
|
||
{
|
||
for (j = 0; VEC_iterate (lambda_vector, DDR_DIST_VECTS (ddr), j, v); j++)
|
||
{
|
||
fprintf (file, "DISTANCE_V (");
|
||
print_lambda_vector (file, v, DDR_NB_LOOPS (ddr));
|
||
fprintf (file, ")\n");
|
||
}
|
||
|
||
for (j = 0; VEC_iterate (lambda_vector, DDR_DIR_VECTS (ddr), j, v); j++)
|
||
{
|
||
fprintf (file, "DIRECTION_V (");
|
||
print_direction_vector (file, v, DDR_NB_LOOPS (ddr));
|
||
fprintf (file, ")\n");
|
||
}
|
||
}
|
||
|
||
fprintf (file, "\n\n");
|
||
}
|
||
|
||
/* Dumps the data dependence relations DDRS in FILE. */
|
||
|
||
void
|
||
dump_ddrs (FILE *file, VEC (ddr_p, heap) *ddrs)
|
||
{
|
||
unsigned int i;
|
||
struct data_dependence_relation *ddr;
|
||
|
||
for (i = 0; VEC_iterate (ddr_p, ddrs, i, ddr); i++)
|
||
dump_data_dependence_relation (file, ddr);
|
||
|
||
fprintf (file, "\n\n");
|
||
}
|
||
|
||
|
||
|
||
/* Estimate the number of iterations from the size of the data and the
|
||
access functions. */
|
||
|
||
static void
|
||
estimate_niter_from_size_of_data (struct loop *loop,
|
||
tree opnd0,
|
||
tree access_fn,
|
||
tree stmt)
|
||
{
|
||
tree estimation = NULL_TREE;
|
||
tree array_size, data_size, element_size;
|
||
tree init, step;
|
||
|
||
init = initial_condition (access_fn);
|
||
step = evolution_part_in_loop_num (access_fn, loop->num);
|
||
|
||
array_size = TYPE_SIZE (TREE_TYPE (opnd0));
|
||
element_size = TYPE_SIZE (TREE_TYPE (TREE_TYPE (opnd0)));
|
||
if (array_size == NULL_TREE
|
||
|| TREE_CODE (array_size) != INTEGER_CST
|
||
|| TREE_CODE (element_size) != INTEGER_CST)
|
||
return;
|
||
|
||
data_size = fold_build2 (EXACT_DIV_EXPR, integer_type_node,
|
||
array_size, element_size);
|
||
|
||
if (init != NULL_TREE
|
||
&& step != NULL_TREE
|
||
&& TREE_CODE (init) == INTEGER_CST
|
||
&& TREE_CODE (step) == INTEGER_CST)
|
||
{
|
||
tree i_plus_s = fold_build2 (PLUS_EXPR, integer_type_node, init, step);
|
||
tree sign = fold_binary (GT_EXPR, boolean_type_node, i_plus_s, init);
|
||
|
||
if (sign == boolean_true_node)
|
||
estimation = fold_build2 (CEIL_DIV_EXPR, integer_type_node,
|
||
fold_build2 (MINUS_EXPR, integer_type_node,
|
||
data_size, init), step);
|
||
|
||
/* When the step is negative, as in PR23386: (init = 3, step =
|
||
0ffffffff, data_size = 100), we have to compute the
|
||
estimation as ceil_div (init, 0 - step) + 1. */
|
||
else if (sign == boolean_false_node)
|
||
estimation =
|
||
fold_build2 (PLUS_EXPR, integer_type_node,
|
||
fold_build2 (CEIL_DIV_EXPR, integer_type_node,
|
||
init,
|
||
fold_build2 (MINUS_EXPR, unsigned_type_node,
|
||
integer_zero_node, step)),
|
||
integer_one_node);
|
||
|
||
if (estimation)
|
||
record_estimate (loop, estimation, boolean_true_node, stmt);
|
||
}
|
||
}
|
||
|
||
/* Given an ARRAY_REF node REF, records its access functions.
|
||
Example: given A[i][3], record in ACCESS_FNS the opnd1 function,
|
||
i.e. the constant "3", then recursively call the function on opnd0,
|
||
i.e. the ARRAY_REF "A[i]".
|
||
If ESTIMATE_ONLY is true, we just set the estimated number of loop
|
||
iterations, we don't store the access function.
|
||
The function returns the base name: "A". */
|
||
|
||
static tree
|
||
analyze_array_indexes (struct loop *loop,
|
||
VEC(tree,heap) **access_fns,
|
||
tree ref, tree stmt,
|
||
bool estimate_only)
|
||
{
|
||
tree opnd0, opnd1;
|
||
tree access_fn;
|
||
|
||
opnd0 = TREE_OPERAND (ref, 0);
|
||
opnd1 = TREE_OPERAND (ref, 1);
|
||
|
||
/* The detection of the evolution function for this data access is
|
||
postponed until the dependence test. This lazy strategy avoids
|
||
the computation of access functions that are of no interest for
|
||
the optimizers. */
|
||
access_fn = instantiate_parameters
|
||
(loop, analyze_scalar_evolution (loop, opnd1));
|
||
|
||
if (estimate_only
|
||
&& chrec_contains_undetermined (loop->estimated_nb_iterations))
|
||
estimate_niter_from_size_of_data (loop, opnd0, access_fn, stmt);
|
||
|
||
if (!estimate_only)
|
||
VEC_safe_push (tree, heap, *access_fns, access_fn);
|
||
|
||
/* Recursively record other array access functions. */
|
||
if (TREE_CODE (opnd0) == ARRAY_REF)
|
||
return analyze_array_indexes (loop, access_fns, opnd0, stmt, estimate_only);
|
||
|
||
/* Return the base name of the data access. */
|
||
else
|
||
return opnd0;
|
||
}
|
||
|
||
/* For an array reference REF contained in STMT, attempt to bound the
|
||
number of iterations in the loop containing STMT */
|
||
|
||
void
|
||
estimate_iters_using_array (tree stmt, tree ref)
|
||
{
|
||
analyze_array_indexes (loop_containing_stmt (stmt), NULL, ref, stmt,
|
||
true);
|
||
}
|
||
|
||
/* For a data reference REF contained in the statement STMT, initialize
|
||
a DATA_REFERENCE structure, and return it. IS_READ flag has to be
|
||
set to true when REF is in the right hand side of an
|
||
assignment. */
|
||
|
||
struct data_reference *
|
||
analyze_array (tree stmt, tree ref, bool is_read)
|
||
{
|
||
struct data_reference *res;
|
||
VEC(tree,heap) *acc_fns;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "(analyze_array \n");
|
||
fprintf (dump_file, " (ref = ");
|
||
print_generic_stmt (dump_file, ref, 0);
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
res = XNEW (struct data_reference);
|
||
|
||
DR_STMT (res) = stmt;
|
||
DR_REF (res) = ref;
|
||
acc_fns = VEC_alloc (tree, heap, 3);
|
||
DR_BASE_OBJECT (res) = analyze_array_indexes
|
||
(loop_containing_stmt (stmt), &acc_fns, ref, stmt, false);
|
||
DR_TYPE (res) = ARRAY_REF_TYPE;
|
||
DR_SET_ACCESS_FNS (res, acc_fns);
|
||
DR_IS_READ (res) = is_read;
|
||
DR_BASE_ADDRESS (res) = NULL_TREE;
|
||
DR_OFFSET (res) = NULL_TREE;
|
||
DR_INIT (res) = NULL_TREE;
|
||
DR_STEP (res) = NULL_TREE;
|
||
DR_OFFSET_MISALIGNMENT (res) = NULL_TREE;
|
||
DR_MEMTAG (res) = NULL_TREE;
|
||
DR_PTR_INFO (res) = NULL;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
|
||
return res;
|
||
}
|
||
|
||
/* Analyze an indirect memory reference, REF, that comes from STMT.
|
||
IS_READ is true if this is an indirect load, and false if it is
|
||
an indirect store.
|
||
Return a new data reference structure representing the indirect_ref, or
|
||
NULL if we cannot describe the access function. */
|
||
|
||
static struct data_reference *
|
||
analyze_indirect_ref (tree stmt, tree ref, bool is_read)
|
||
{
|
||
struct loop *loop = loop_containing_stmt (stmt);
|
||
tree ptr_ref = TREE_OPERAND (ref, 0);
|
||
tree access_fn = analyze_scalar_evolution (loop, ptr_ref);
|
||
tree init = initial_condition_in_loop_num (access_fn, loop->num);
|
||
tree base_address = NULL_TREE, evolution, step = NULL_TREE;
|
||
struct ptr_info_def *ptr_info = NULL;
|
||
|
||
if (TREE_CODE (ptr_ref) == SSA_NAME)
|
||
ptr_info = SSA_NAME_PTR_INFO (ptr_ref);
|
||
|
||
STRIP_NOPS (init);
|
||
if (access_fn == chrec_dont_know || !init || init == chrec_dont_know)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nBad access function of ptr: ");
|
||
print_generic_expr (dump_file, ref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL;
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nAccess function of ptr: ");
|
||
print_generic_expr (dump_file, access_fn, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
|
||
if (!expr_invariant_in_loop_p (loop, init))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "\ninitial condition is not loop invariant.\n");
|
||
}
|
||
else
|
||
{
|
||
base_address = init;
|
||
evolution = evolution_part_in_loop_num (access_fn, loop->num);
|
||
if (evolution != chrec_dont_know)
|
||
{
|
||
if (!evolution)
|
||
step = ssize_int (0);
|
||
else
|
||
{
|
||
if (TREE_CODE (evolution) == INTEGER_CST)
|
||
step = fold_convert (ssizetype, evolution);
|
||
else
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "\nnon constant step for ptr access.\n");
|
||
}
|
||
}
|
||
else
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "\nunknown evolution of ptr.\n");
|
||
}
|
||
return init_data_ref (stmt, ref, NULL_TREE, access_fn, is_read, base_address,
|
||
NULL_TREE, step, NULL_TREE, NULL_TREE,
|
||
ptr_info, POINTER_REF_TYPE);
|
||
}
|
||
|
||
/* For a data reference REF contained in the statement STMT, initialize
|
||
a DATA_REFERENCE structure, and return it. */
|
||
|
||
struct data_reference *
|
||
init_data_ref (tree stmt,
|
||
tree ref,
|
||
tree base,
|
||
tree access_fn,
|
||
bool is_read,
|
||
tree base_address,
|
||
tree init_offset,
|
||
tree step,
|
||
tree misalign,
|
||
tree memtag,
|
||
struct ptr_info_def *ptr_info,
|
||
enum data_ref_type type)
|
||
{
|
||
struct data_reference *res;
|
||
VEC(tree,heap) *acc_fns;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "(init_data_ref \n");
|
||
fprintf (dump_file, " (ref = ");
|
||
print_generic_stmt (dump_file, ref, 0);
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
res = XNEW (struct data_reference);
|
||
|
||
DR_STMT (res) = stmt;
|
||
DR_REF (res) = ref;
|
||
DR_BASE_OBJECT (res) = base;
|
||
DR_TYPE (res) = type;
|
||
acc_fns = VEC_alloc (tree, heap, 3);
|
||
DR_SET_ACCESS_FNS (res, acc_fns);
|
||
VEC_quick_push (tree, DR_ACCESS_FNS (res), access_fn);
|
||
DR_IS_READ (res) = is_read;
|
||
DR_BASE_ADDRESS (res) = base_address;
|
||
DR_OFFSET (res) = init_offset;
|
||
DR_INIT (res) = NULL_TREE;
|
||
DR_STEP (res) = step;
|
||
DR_OFFSET_MISALIGNMENT (res) = misalign;
|
||
DR_MEMTAG (res) = memtag;
|
||
DR_PTR_INFO (res) = ptr_info;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
|
||
return res;
|
||
}
|
||
|
||
/* Function strip_conversions
|
||
|
||
Strip conversions that don't narrow the mode. */
|
||
|
||
static tree
|
||
strip_conversion (tree expr)
|
||
{
|
||
tree to, ti, oprnd0;
|
||
|
||
while (TREE_CODE (expr) == NOP_EXPR || TREE_CODE (expr) == CONVERT_EXPR)
|
||
{
|
||
to = TREE_TYPE (expr);
|
||
oprnd0 = TREE_OPERAND (expr, 0);
|
||
ti = TREE_TYPE (oprnd0);
|
||
|
||
if (!INTEGRAL_TYPE_P (to) || !INTEGRAL_TYPE_P (ti))
|
||
return NULL_TREE;
|
||
if (GET_MODE_SIZE (TYPE_MODE (to)) < GET_MODE_SIZE (TYPE_MODE (ti)))
|
||
return NULL_TREE;
|
||
|
||
expr = oprnd0;
|
||
}
|
||
return expr;
|
||
}
|
||
|
||
|
||
/* Function analyze_offset_expr
|
||
|
||
Given an offset expression EXPR received from get_inner_reference, analyze
|
||
it and create an expression for INITIAL_OFFSET by substituting the variables
|
||
of EXPR with initial_condition of the corresponding access_fn in the loop.
|
||
E.g.,
|
||
for i
|
||
for (j = 3; j < N; j++)
|
||
a[j].b[i][j] = 0;
|
||
|
||
For a[j].b[i][j], EXPR will be 'i * C_i + j * C_j + C'. 'i' cannot be
|
||
substituted, since its access_fn in the inner loop is i. 'j' will be
|
||
substituted with 3. An INITIAL_OFFSET will be 'i * C_i + C`', where
|
||
C` = 3 * C_j + C.
|
||
|
||
Compute MISALIGN (the misalignment of the data reference initial access from
|
||
its base). Misalignment can be calculated only if all the variables can be
|
||
substituted with constants, otherwise, we record maximum possible alignment
|
||
in ALIGNED_TO. In the above example, since 'i' cannot be substituted, MISALIGN
|
||
will be NULL_TREE, and the biggest divider of C_i (a power of 2) will be
|
||
recorded in ALIGNED_TO.
|
||
|
||
STEP is an evolution of the data reference in this loop in bytes.
|
||
In the above example, STEP is C_j.
|
||
|
||
Return FALSE, if the analysis fails, e.g., there is no access_fn for a
|
||
variable. In this case, all the outputs (INITIAL_OFFSET, MISALIGN, ALIGNED_TO
|
||
and STEP) are NULL_TREEs. Otherwise, return TRUE.
|
||
|
||
*/
|
||
|
||
static bool
|
||
analyze_offset_expr (tree expr,
|
||
struct loop *loop,
|
||
tree *initial_offset,
|
||
tree *misalign,
|
||
tree *aligned_to,
|
||
tree *step)
|
||
{
|
||
tree oprnd0;
|
||
tree oprnd1;
|
||
tree left_offset = ssize_int (0);
|
||
tree right_offset = ssize_int (0);
|
||
tree left_misalign = ssize_int (0);
|
||
tree right_misalign = ssize_int (0);
|
||
tree left_step = ssize_int (0);
|
||
tree right_step = ssize_int (0);
|
||
enum tree_code code;
|
||
tree init, evolution;
|
||
tree left_aligned_to = NULL_TREE, right_aligned_to = NULL_TREE;
|
||
|
||
*step = NULL_TREE;
|
||
*misalign = NULL_TREE;
|
||
*aligned_to = NULL_TREE;
|
||
*initial_offset = NULL_TREE;
|
||
|
||
/* Strip conversions that don't narrow the mode. */
|
||
expr = strip_conversion (expr);
|
||
if (!expr)
|
||
return false;
|
||
|
||
/* Stop conditions:
|
||
1. Constant. */
|
||
if (TREE_CODE (expr) == INTEGER_CST)
|
||
{
|
||
*initial_offset = fold_convert (ssizetype, expr);
|
||
*misalign = fold_convert (ssizetype, expr);
|
||
*step = ssize_int (0);
|
||
return true;
|
||
}
|
||
|
||
/* 2. Variable. Try to substitute with initial_condition of the corresponding
|
||
access_fn in the current loop. */
|
||
if (SSA_VAR_P (expr))
|
||
{
|
||
tree access_fn = analyze_scalar_evolution (loop, expr);
|
||
|
||
if (access_fn == chrec_dont_know)
|
||
/* No access_fn. */
|
||
return false;
|
||
|
||
init = initial_condition_in_loop_num (access_fn, loop->num);
|
||
if (!expr_invariant_in_loop_p (loop, init))
|
||
/* Not enough information: may be not loop invariant.
|
||
E.g., for a[b[i]], we get a[D], where D=b[i]. EXPR is D, its
|
||
initial_condition is D, but it depends on i - loop's induction
|
||
variable. */
|
||
return false;
|
||
|
||
evolution = evolution_part_in_loop_num (access_fn, loop->num);
|
||
if (evolution && TREE_CODE (evolution) != INTEGER_CST)
|
||
/* Evolution is not constant. */
|
||
return false;
|
||
|
||
if (TREE_CODE (init) == INTEGER_CST)
|
||
*misalign = fold_convert (ssizetype, init);
|
||
else
|
||
/* Not constant, misalignment cannot be calculated. */
|
||
*misalign = NULL_TREE;
|
||
|
||
*initial_offset = fold_convert (ssizetype, init);
|
||
|
||
*step = evolution ? fold_convert (ssizetype, evolution) : ssize_int (0);
|
||
return true;
|
||
}
|
||
|
||
/* Recursive computation. */
|
||
if (!BINARY_CLASS_P (expr))
|
||
{
|
||
/* We expect to get binary expressions (PLUS/MINUS and MULT). */
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nNot binary expression ");
|
||
print_generic_expr (dump_file, expr, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return false;
|
||
}
|
||
oprnd0 = TREE_OPERAND (expr, 0);
|
||
oprnd1 = TREE_OPERAND (expr, 1);
|
||
|
||
if (!analyze_offset_expr (oprnd0, loop, &left_offset, &left_misalign,
|
||
&left_aligned_to, &left_step)
|
||
|| !analyze_offset_expr (oprnd1, loop, &right_offset, &right_misalign,
|
||
&right_aligned_to, &right_step))
|
||
return false;
|
||
|
||
/* The type of the operation: plus, minus or mult. */
|
||
code = TREE_CODE (expr);
|
||
switch (code)
|
||
{
|
||
case MULT_EXPR:
|
||
if (TREE_CODE (right_offset) != INTEGER_CST)
|
||
/* RIGHT_OFFSET can be not constant. For example, for arrays of variable
|
||
sized types.
|
||
FORNOW: We don't support such cases. */
|
||
return false;
|
||
|
||
/* Strip conversions that don't narrow the mode. */
|
||
left_offset = strip_conversion (left_offset);
|
||
if (!left_offset)
|
||
return false;
|
||
/* Misalignment computation. */
|
||
if (SSA_VAR_P (left_offset))
|
||
{
|
||
/* If the left side contains variables that can't be substituted with
|
||
constants, the misalignment is unknown. However, if the right side
|
||
is a multiple of some alignment, we know that the expression is
|
||
aligned to it. Therefore, we record such maximum possible value.
|
||
*/
|
||
*misalign = NULL_TREE;
|
||
*aligned_to = ssize_int (highest_pow2_factor (right_offset));
|
||
}
|
||
else
|
||
{
|
||
/* The left operand was successfully substituted with constant. */
|
||
if (left_misalign)
|
||
{
|
||
/* In case of EXPR '(i * C1 + j) * C2', LEFT_MISALIGN is
|
||
NULL_TREE. */
|
||
*misalign = size_binop (code, left_misalign, right_misalign);
|
||
if (left_aligned_to && right_aligned_to)
|
||
*aligned_to = size_binop (MIN_EXPR, left_aligned_to,
|
||
right_aligned_to);
|
||
else
|
||
*aligned_to = left_aligned_to ?
|
||
left_aligned_to : right_aligned_to;
|
||
}
|
||
else
|
||
*misalign = NULL_TREE;
|
||
}
|
||
|
||
/* Step calculation. */
|
||
/* Multiply the step by the right operand. */
|
||
*step = size_binop (MULT_EXPR, left_step, right_offset);
|
||
break;
|
||
|
||
case PLUS_EXPR:
|
||
case MINUS_EXPR:
|
||
/* Combine the recursive calculations for step and misalignment. */
|
||
*step = size_binop (code, left_step, right_step);
|
||
|
||
/* Unknown alignment. */
|
||
if ((!left_misalign && !left_aligned_to)
|
||
|| (!right_misalign && !right_aligned_to))
|
||
{
|
||
*misalign = NULL_TREE;
|
||
*aligned_to = NULL_TREE;
|
||
break;
|
||
}
|
||
|
||
if (left_misalign && right_misalign)
|
||
*misalign = size_binop (code, left_misalign, right_misalign);
|
||
else
|
||
*misalign = left_misalign ? left_misalign : right_misalign;
|
||
|
||
if (left_aligned_to && right_aligned_to)
|
||
*aligned_to = size_binop (MIN_EXPR, left_aligned_to, right_aligned_to);
|
||
else
|
||
*aligned_to = left_aligned_to ? left_aligned_to : right_aligned_to;
|
||
|
||
break;
|
||
|
||
default:
|
||
gcc_unreachable ();
|
||
}
|
||
|
||
/* Compute offset. */
|
||
*initial_offset = fold_convert (ssizetype,
|
||
fold_build2 (code, TREE_TYPE (left_offset),
|
||
left_offset,
|
||
right_offset));
|
||
return true;
|
||
}
|
||
|
||
/* Function address_analysis
|
||
|
||
Return the BASE of the address expression EXPR.
|
||
Also compute the OFFSET from BASE, MISALIGN and STEP.
|
||
|
||
Input:
|
||
EXPR - the address expression that is being analyzed
|
||
STMT - the statement that contains EXPR or its original memory reference
|
||
IS_READ - TRUE if STMT reads from EXPR, FALSE if writes to EXPR
|
||
DR - data_reference struct for the original memory reference
|
||
|
||
Output:
|
||
BASE (returned value) - the base of the data reference EXPR.
|
||
INITIAL_OFFSET - initial offset of EXPR from BASE (an expression)
|
||
MISALIGN - offset of EXPR from BASE in bytes (a constant) or NULL_TREE if the
|
||
computation is impossible
|
||
ALIGNED_TO - maximum alignment of EXPR or NULL_TREE if MISALIGN can be
|
||
calculated (doesn't depend on variables)
|
||
STEP - evolution of EXPR in the loop
|
||
|
||
If something unexpected is encountered (an unsupported form of data-ref),
|
||
then NULL_TREE is returned.
|
||
*/
|
||
|
||
static tree
|
||
address_analysis (tree expr, tree stmt, bool is_read, struct data_reference *dr,
|
||
tree *offset, tree *misalign, tree *aligned_to, tree *step)
|
||
{
|
||
tree oprnd0, oprnd1, base_address, offset_expr, base_addr0, base_addr1;
|
||
tree address_offset = ssize_int (0), address_misalign = ssize_int (0);
|
||
tree dummy, address_aligned_to = NULL_TREE;
|
||
struct ptr_info_def *dummy1;
|
||
subvar_t dummy2;
|
||
|
||
switch (TREE_CODE (expr))
|
||
{
|
||
case PLUS_EXPR:
|
||
case MINUS_EXPR:
|
||
/* EXPR is of form {base +/- offset} (or {offset +/- base}). */
|
||
oprnd0 = TREE_OPERAND (expr, 0);
|
||
oprnd1 = TREE_OPERAND (expr, 1);
|
||
|
||
STRIP_NOPS (oprnd0);
|
||
STRIP_NOPS (oprnd1);
|
||
|
||
/* Recursively try to find the base of the address contained in EXPR.
|
||
For offset, the returned base will be NULL. */
|
||
base_addr0 = address_analysis (oprnd0, stmt, is_read, dr, &address_offset,
|
||
&address_misalign, &address_aligned_to,
|
||
step);
|
||
|
||
base_addr1 = address_analysis (oprnd1, stmt, is_read, dr, &address_offset,
|
||
&address_misalign, &address_aligned_to,
|
||
step);
|
||
|
||
/* We support cases where only one of the operands contains an
|
||
address. */
|
||
if ((base_addr0 && base_addr1) || (!base_addr0 && !base_addr1))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file,
|
||
"\neither more than one address or no addresses in expr ");
|
||
print_generic_expr (dump_file, expr, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* To revert STRIP_NOPS. */
|
||
oprnd0 = TREE_OPERAND (expr, 0);
|
||
oprnd1 = TREE_OPERAND (expr, 1);
|
||
|
||
offset_expr = base_addr0 ?
|
||
fold_convert (ssizetype, oprnd1) : fold_convert (ssizetype, oprnd0);
|
||
|
||
/* EXPR is of form {base +/- offset} (or {offset +/- base}). If offset is
|
||
a number, we can add it to the misalignment value calculated for base,
|
||
otherwise, misalignment is NULL. */
|
||
if (TREE_CODE (offset_expr) == INTEGER_CST && address_misalign)
|
||
{
|
||
*misalign = size_binop (TREE_CODE (expr), address_misalign,
|
||
offset_expr);
|
||
*aligned_to = address_aligned_to;
|
||
}
|
||
else
|
||
{
|
||
*misalign = NULL_TREE;
|
||
*aligned_to = NULL_TREE;
|
||
}
|
||
|
||
/* Combine offset (from EXPR {base + offset}) with the offset calculated
|
||
for base. */
|
||
*offset = size_binop (TREE_CODE (expr), address_offset, offset_expr);
|
||
return base_addr0 ? base_addr0 : base_addr1;
|
||
|
||
case ADDR_EXPR:
|
||
base_address = object_analysis (TREE_OPERAND (expr, 0), stmt, is_read,
|
||
&dr, offset, misalign, aligned_to, step,
|
||
&dummy, &dummy1, &dummy2);
|
||
return base_address;
|
||
|
||
case SSA_NAME:
|
||
if (!POINTER_TYPE_P (TREE_TYPE (expr)))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nnot pointer SSA_NAME ");
|
||
print_generic_expr (dump_file, expr, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
*aligned_to = ssize_int (TYPE_ALIGN_UNIT (TREE_TYPE (TREE_TYPE (expr))));
|
||
*misalign = ssize_int (0);
|
||
*offset = ssize_int (0);
|
||
*step = ssize_int (0);
|
||
return expr;
|
||
|
||
default:
|
||
return NULL_TREE;
|
||
}
|
||
}
|
||
|
||
|
||
/* Function object_analysis
|
||
|
||
Create a data-reference structure DR for MEMREF.
|
||
Return the BASE of the data reference MEMREF if the analysis is possible.
|
||
Also compute the INITIAL_OFFSET from BASE, MISALIGN and STEP.
|
||
E.g., for EXPR a.b[i] + 4B, BASE is a, and OFFSET is the overall offset
|
||
'a.b[i] + 4B' from a (can be an expression), MISALIGN is an OFFSET
|
||
instantiated with initial_conditions of access_functions of variables,
|
||
and STEP is the evolution of the DR_REF in this loop.
|
||
|
||
Function get_inner_reference is used for the above in case of ARRAY_REF and
|
||
COMPONENT_REF.
|
||
|
||
The structure of the function is as follows:
|
||
Part 1:
|
||
Case 1. For handled_component_p refs
|
||
1.1 build data-reference structure for MEMREF
|
||
1.2 call get_inner_reference
|
||
1.2.1 analyze offset expr received from get_inner_reference
|
||
(fall through with BASE)
|
||
Case 2. For declarations
|
||
2.1 set MEMTAG
|
||
Case 3. For INDIRECT_REFs
|
||
3.1 build data-reference structure for MEMREF
|
||
3.2 analyze evolution and initial condition of MEMREF
|
||
3.3 set data-reference structure for MEMREF
|
||
3.4 call address_analysis to analyze INIT of the access function
|
||
3.5 extract memory tag
|
||
|
||
Part 2:
|
||
Combine the results of object and address analysis to calculate
|
||
INITIAL_OFFSET, STEP and misalignment info.
|
||
|
||
Input:
|
||
MEMREF - the memory reference that is being analyzed
|
||
STMT - the statement that contains MEMREF
|
||
IS_READ - TRUE if STMT reads from MEMREF, FALSE if writes to MEMREF
|
||
|
||
Output:
|
||
BASE_ADDRESS (returned value) - the base address of the data reference MEMREF
|
||
E.g, if MEMREF is a.b[k].c[i][j] the returned
|
||
base is &a.
|
||
DR - data_reference struct for MEMREF
|
||
INITIAL_OFFSET - initial offset of MEMREF from BASE (an expression)
|
||
MISALIGN - offset of MEMREF from BASE in bytes (a constant) modulo alignment of
|
||
ALIGNMENT or NULL_TREE if the computation is impossible
|
||
ALIGNED_TO - maximum alignment of EXPR or NULL_TREE if MISALIGN can be
|
||
calculated (doesn't depend on variables)
|
||
STEP - evolution of the DR_REF in the loop
|
||
MEMTAG - memory tag for aliasing purposes
|
||
PTR_INFO - NULL or points-to aliasing info from a pointer SSA_NAME
|
||
SUBVARS - Sub-variables of the variable
|
||
|
||
If the analysis of MEMREF evolution in the loop fails, NULL_TREE is returned,
|
||
but DR can be created anyway.
|
||
|
||
*/
|
||
|
||
static tree
|
||
object_analysis (tree memref, tree stmt, bool is_read,
|
||
struct data_reference **dr, tree *offset, tree *misalign,
|
||
tree *aligned_to, tree *step, tree *memtag,
|
||
struct ptr_info_def **ptr_info, subvar_t *subvars)
|
||
{
|
||
tree base = NULL_TREE, base_address = NULL_TREE;
|
||
tree object_offset = ssize_int (0), object_misalign = ssize_int (0);
|
||
tree object_step = ssize_int (0), address_step = ssize_int (0);
|
||
tree address_offset = ssize_int (0), address_misalign = ssize_int (0);
|
||
HOST_WIDE_INT pbitsize, pbitpos;
|
||
tree poffset, bit_pos_in_bytes;
|
||
enum machine_mode pmode;
|
||
int punsignedp, pvolatilep;
|
||
tree ptr_step = ssize_int (0), ptr_init = NULL_TREE;
|
||
struct loop *loop = loop_containing_stmt (stmt);
|
||
struct data_reference *ptr_dr = NULL;
|
||
tree object_aligned_to = NULL_TREE, address_aligned_to = NULL_TREE;
|
||
tree comp_ref = NULL_TREE;
|
||
|
||
*ptr_info = NULL;
|
||
|
||
/* Part 1: */
|
||
/* Case 1. handled_component_p refs. */
|
||
if (handled_component_p (memref))
|
||
{
|
||
/* 1.1 build data-reference structure for MEMREF. */
|
||
if (!(*dr))
|
||
{
|
||
if (TREE_CODE (memref) == ARRAY_REF)
|
||
*dr = analyze_array (stmt, memref, is_read);
|
||
else if (TREE_CODE (memref) == COMPONENT_REF)
|
||
comp_ref = memref;
|
||
else
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\ndata-ref of unsupported type ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
}
|
||
|
||
/* 1.2 call get_inner_reference. */
|
||
/* Find the base and the offset from it. */
|
||
base = get_inner_reference (memref, &pbitsize, &pbitpos, &poffset,
|
||
&pmode, &punsignedp, &pvolatilep, false);
|
||
if (!base)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nfailed to get inner ref for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* 1.2.1 analyze offset expr received from get_inner_reference. */
|
||
if (poffset
|
||
&& !analyze_offset_expr (poffset, loop, &object_offset,
|
||
&object_misalign, &object_aligned_to,
|
||
&object_step))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nfailed to compute offset or step for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Add bit position to OFFSET and MISALIGN. */
|
||
|
||
bit_pos_in_bytes = ssize_int (pbitpos/BITS_PER_UNIT);
|
||
/* Check that there is no remainder in bits. */
|
||
if (pbitpos%BITS_PER_UNIT)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "\nbit offset alignment.\n");
|
||
return NULL_TREE;
|
||
}
|
||
object_offset = size_binop (PLUS_EXPR, bit_pos_in_bytes, object_offset);
|
||
if (object_misalign)
|
||
object_misalign = size_binop (PLUS_EXPR, object_misalign,
|
||
bit_pos_in_bytes);
|
||
|
||
memref = base; /* To continue analysis of BASE. */
|
||
/* fall through */
|
||
}
|
||
|
||
/* Part 1: Case 2. Declarations. */
|
||
if (DECL_P (memref))
|
||
{
|
||
/* We expect to get a decl only if we already have a DR, or with
|
||
COMPONENT_REFs of type 'a[i].b'. */
|
||
if (!(*dr))
|
||
{
|
||
if (comp_ref && TREE_CODE (TREE_OPERAND (comp_ref, 0)) == ARRAY_REF)
|
||
{
|
||
*dr = analyze_array (stmt, TREE_OPERAND (comp_ref, 0), is_read);
|
||
if (DR_NUM_DIMENSIONS (*dr) != 1)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\n multidimensional component ref ");
|
||
print_generic_expr (dump_file, comp_ref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nunhandled decl ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
}
|
||
|
||
/* TODO: if during the analysis of INDIRECT_REF we get to an object, put
|
||
the object in BASE_OBJECT field if we can prove that this is O.K.,
|
||
i.e., the data-ref access is bounded by the bounds of the BASE_OBJECT.
|
||
(e.g., if the object is an array base 'a', where 'a[N]', we must prove
|
||
that every access with 'p' (the original INDIRECT_REF based on '&a')
|
||
in the loop is within the array boundaries - from a[0] to a[N-1]).
|
||
Otherwise, our alias analysis can be incorrect.
|
||
Even if an access function based on BASE_OBJECT can't be build, update
|
||
BASE_OBJECT field to enable us to prove that two data-refs are
|
||
different (without access function, distance analysis is impossible).
|
||
*/
|
||
if (SSA_VAR_P (memref) && var_can_have_subvars (memref))
|
||
*subvars = get_subvars_for_var (memref);
|
||
base_address = build_fold_addr_expr (memref);
|
||
/* 2.1 set MEMTAG. */
|
||
*memtag = memref;
|
||
}
|
||
|
||
/* Part 1: Case 3. INDIRECT_REFs. */
|
||
else if (TREE_CODE (memref) == INDIRECT_REF)
|
||
{
|
||
tree ptr_ref = TREE_OPERAND (memref, 0);
|
||
if (TREE_CODE (ptr_ref) == SSA_NAME)
|
||
*ptr_info = SSA_NAME_PTR_INFO (ptr_ref);
|
||
|
||
/* 3.1 build data-reference structure for MEMREF. */
|
||
ptr_dr = analyze_indirect_ref (stmt, memref, is_read);
|
||
if (!ptr_dr)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nfailed to create dr for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* 3.2 analyze evolution and initial condition of MEMREF. */
|
||
ptr_step = DR_STEP (ptr_dr);
|
||
ptr_init = DR_BASE_ADDRESS (ptr_dr);
|
||
if (!ptr_init || !ptr_step || !POINTER_TYPE_P (TREE_TYPE (ptr_init)))
|
||
{
|
||
*dr = (*dr) ? *dr : ptr_dr;
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nbad pointer access ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
if (integer_zerop (ptr_step) && !(*dr))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "\nptr is loop invariant.\n");
|
||
*dr = ptr_dr;
|
||
return NULL_TREE;
|
||
|
||
/* If there exists DR for MEMREF, we are analyzing the base of
|
||
handled component (PTR_INIT), which not necessary has evolution in
|
||
the loop. */
|
||
}
|
||
object_step = size_binop (PLUS_EXPR, object_step, ptr_step);
|
||
|
||
/* 3.3 set data-reference structure for MEMREF. */
|
||
if (!*dr)
|
||
*dr = ptr_dr;
|
||
|
||
/* 3.4 call address_analysis to analyze INIT of the access
|
||
function. */
|
||
base_address = address_analysis (ptr_init, stmt, is_read, *dr,
|
||
&address_offset, &address_misalign,
|
||
&address_aligned_to, &address_step);
|
||
if (!base_address)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nfailed to analyze address ");
|
||
print_generic_expr (dump_file, ptr_init, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* 3.5 extract memory tag. */
|
||
switch (TREE_CODE (base_address))
|
||
{
|
||
case SSA_NAME:
|
||
*memtag = get_var_ann (SSA_NAME_VAR (base_address))->symbol_mem_tag;
|
||
if (!(*memtag) && TREE_CODE (TREE_OPERAND (memref, 0)) == SSA_NAME)
|
||
*memtag = get_var_ann (
|
||
SSA_NAME_VAR (TREE_OPERAND (memref, 0)))->symbol_mem_tag;
|
||
break;
|
||
case ADDR_EXPR:
|
||
*memtag = TREE_OPERAND (base_address, 0);
|
||
break;
|
||
default:
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\nno memtag for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
*memtag = NULL_TREE;
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (!base_address)
|
||
{
|
||
/* MEMREF cannot be analyzed. */
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\ndata-ref of unsupported type ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL_TREE;
|
||
}
|
||
|
||
if (comp_ref)
|
||
DR_REF (*dr) = comp_ref;
|
||
|
||
if (SSA_VAR_P (*memtag) && var_can_have_subvars (*memtag))
|
||
*subvars = get_subvars_for_var (*memtag);
|
||
|
||
/* Part 2: Combine the results of object and address analysis to calculate
|
||
INITIAL_OFFSET, STEP and misalignment info. */
|
||
*offset = size_binop (PLUS_EXPR, object_offset, address_offset);
|
||
|
||
if ((!object_misalign && !object_aligned_to)
|
||
|| (!address_misalign && !address_aligned_to))
|
||
{
|
||
*misalign = NULL_TREE;
|
||
*aligned_to = NULL_TREE;
|
||
}
|
||
else
|
||
{
|
||
if (object_misalign && address_misalign)
|
||
*misalign = size_binop (PLUS_EXPR, object_misalign, address_misalign);
|
||
else
|
||
*misalign = object_misalign ? object_misalign : address_misalign;
|
||
if (object_aligned_to && address_aligned_to)
|
||
*aligned_to = size_binop (MIN_EXPR, object_aligned_to,
|
||
address_aligned_to);
|
||
else
|
||
*aligned_to = object_aligned_to ?
|
||
object_aligned_to : address_aligned_to;
|
||
}
|
||
*step = size_binop (PLUS_EXPR, object_step, address_step);
|
||
|
||
return base_address;
|
||
}
|
||
|
||
/* Function analyze_offset.
|
||
|
||
Extract INVARIANT and CONSTANT parts from OFFSET.
|
||
|
||
*/
|
||
static bool
|
||
analyze_offset (tree offset, tree *invariant, tree *constant)
|
||
{
|
||
tree op0, op1, constant_0, constant_1, invariant_0, invariant_1;
|
||
enum tree_code code = TREE_CODE (offset);
|
||
|
||
*invariant = NULL_TREE;
|
||
*constant = NULL_TREE;
|
||
|
||
/* Not PLUS/MINUS expression - recursion stop condition. */
|
||
if (code != PLUS_EXPR && code != MINUS_EXPR)
|
||
{
|
||
if (TREE_CODE (offset) == INTEGER_CST)
|
||
*constant = offset;
|
||
else
|
||
*invariant = offset;
|
||
return true;
|
||
}
|
||
|
||
op0 = TREE_OPERAND (offset, 0);
|
||
op1 = TREE_OPERAND (offset, 1);
|
||
|
||
/* Recursive call with the operands. */
|
||
if (!analyze_offset (op0, &invariant_0, &constant_0)
|
||
|| !analyze_offset (op1, &invariant_1, &constant_1))
|
||
return false;
|
||
|
||
/* Combine the results. Add negation to the subtrahend in case of
|
||
subtraction. */
|
||
if (constant_0 && constant_1)
|
||
return false;
|
||
*constant = constant_0 ? constant_0 : constant_1;
|
||
if (code == MINUS_EXPR && constant_1)
|
||
*constant = fold_build1 (NEGATE_EXPR, TREE_TYPE (*constant), *constant);
|
||
|
||
if (invariant_0 && invariant_1)
|
||
*invariant =
|
||
fold_build2 (code, TREE_TYPE (invariant_0), invariant_0, invariant_1);
|
||
else
|
||
{
|
||
*invariant = invariant_0 ? invariant_0 : invariant_1;
|
||
if (code == MINUS_EXPR && invariant_1)
|
||
*invariant =
|
||
fold_build1 (NEGATE_EXPR, TREE_TYPE (*invariant), *invariant);
|
||
}
|
||
return true;
|
||
}
|
||
|
||
/* Free the memory used by the data reference DR. */
|
||
|
||
static void
|
||
free_data_ref (data_reference_p dr)
|
||
{
|
||
DR_FREE_ACCESS_FNS (dr);
|
||
free (dr);
|
||
}
|
||
|
||
/* Function create_data_ref.
|
||
|
||
Create a data-reference structure for MEMREF. Set its DR_BASE_ADDRESS,
|
||
DR_OFFSET, DR_INIT, DR_STEP, DR_OFFSET_MISALIGNMENT, DR_ALIGNED_TO,
|
||
DR_MEMTAG, and DR_POINTSTO_INFO fields.
|
||
|
||
Input:
|
||
MEMREF - the memory reference that is being analyzed
|
||
STMT - the statement that contains MEMREF
|
||
IS_READ - TRUE if STMT reads from MEMREF, FALSE if writes to MEMREF
|
||
|
||
Output:
|
||
DR (returned value) - data_reference struct for MEMREF
|
||
*/
|
||
|
||
static struct data_reference *
|
||
create_data_ref (tree memref, tree stmt, bool is_read)
|
||
{
|
||
struct data_reference *dr = NULL;
|
||
tree base_address, offset, step, misalign, memtag;
|
||
struct loop *loop = loop_containing_stmt (stmt);
|
||
tree invariant = NULL_TREE, constant = NULL_TREE;
|
||
tree type_size, init_cond;
|
||
struct ptr_info_def *ptr_info;
|
||
subvar_t subvars = NULL;
|
||
tree aligned_to, type = NULL_TREE, orig_offset;
|
||
|
||
if (!memref)
|
||
return NULL;
|
||
|
||
base_address = object_analysis (memref, stmt, is_read, &dr, &offset,
|
||
&misalign, &aligned_to, &step, &memtag,
|
||
&ptr_info, &subvars);
|
||
if (!dr || !base_address)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\ncreate_data_ref: failed to create a dr for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL;
|
||
}
|
||
|
||
DR_BASE_ADDRESS (dr) = base_address;
|
||
DR_OFFSET (dr) = offset;
|
||
DR_INIT (dr) = ssize_int (0);
|
||
DR_STEP (dr) = step;
|
||
DR_OFFSET_MISALIGNMENT (dr) = misalign;
|
||
DR_ALIGNED_TO (dr) = aligned_to;
|
||
DR_MEMTAG (dr) = memtag;
|
||
DR_PTR_INFO (dr) = ptr_info;
|
||
DR_SUBVARS (dr) = subvars;
|
||
|
||
type_size = fold_convert (ssizetype, TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr))));
|
||
|
||
/* Extract CONSTANT and INVARIANT from OFFSET. */
|
||
/* Remove cast from OFFSET and restore it for INVARIANT part. */
|
||
orig_offset = offset;
|
||
STRIP_NOPS (offset);
|
||
if (offset != orig_offset)
|
||
type = TREE_TYPE (orig_offset);
|
||
if (!analyze_offset (offset, &invariant, &constant))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "\ncreate_data_ref: failed to analyze dr's");
|
||
fprintf (dump_file, " offset for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
return NULL;
|
||
}
|
||
if (type && invariant)
|
||
invariant = fold_convert (type, invariant);
|
||
|
||
/* Put CONSTANT part of OFFSET in DR_INIT and INVARIANT in DR_OFFSET field
|
||
of DR. */
|
||
if (constant)
|
||
{
|
||
DR_INIT (dr) = fold_convert (ssizetype, constant);
|
||
init_cond = fold_build2 (TRUNC_DIV_EXPR, TREE_TYPE (constant),
|
||
constant, type_size);
|
||
}
|
||
else
|
||
DR_INIT (dr) = init_cond = ssize_int (0);
|
||
|
||
if (invariant)
|
||
DR_OFFSET (dr) = invariant;
|
||
else
|
||
DR_OFFSET (dr) = ssize_int (0);
|
||
|
||
/* Change the access function for INIDIRECT_REFs, according to
|
||
DR_BASE_ADDRESS. Analyze OFFSET calculated in object_analysis. OFFSET is
|
||
an expression that can contain loop invariant expressions and constants.
|
||
We put the constant part in the initial condition of the access function
|
||
(for data dependence tests), and in DR_INIT of the data-ref. The loop
|
||
invariant part is put in DR_OFFSET.
|
||
The evolution part of the access function is STEP calculated in
|
||
object_analysis divided by the size of data type.
|
||
*/
|
||
if (!DR_BASE_OBJECT (dr)
|
||
|| (TREE_CODE (memref) == COMPONENT_REF && DR_NUM_DIMENSIONS (dr) == 1))
|
||
{
|
||
tree access_fn;
|
||
tree new_step;
|
||
|
||
/* Update access function. */
|
||
access_fn = DR_ACCESS_FN (dr, 0);
|
||
if (automatically_generated_chrec_p (access_fn))
|
||
{
|
||
free_data_ref (dr);
|
||
return NULL;
|
||
}
|
||
|
||
new_step = size_binop (TRUNC_DIV_EXPR,
|
||
fold_convert (ssizetype, step), type_size);
|
||
|
||
init_cond = chrec_convert (chrec_type (access_fn), init_cond, stmt);
|
||
new_step = chrec_convert (chrec_type (access_fn), new_step, stmt);
|
||
if (automatically_generated_chrec_p (init_cond)
|
||
|| automatically_generated_chrec_p (new_step))
|
||
{
|
||
free_data_ref (dr);
|
||
return NULL;
|
||
}
|
||
access_fn = chrec_replace_initial_condition (access_fn, init_cond);
|
||
access_fn = reset_evolution_in_loop (loop->num, access_fn, new_step);
|
||
|
||
VEC_replace (tree, DR_ACCESS_FNS (dr), 0, access_fn);
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
struct ptr_info_def *pi = DR_PTR_INFO (dr);
|
||
|
||
fprintf (dump_file, "\nCreated dr for ");
|
||
print_generic_expr (dump_file, memref, TDF_SLIM);
|
||
fprintf (dump_file, "\n\tbase_address: ");
|
||
print_generic_expr (dump_file, DR_BASE_ADDRESS (dr), TDF_SLIM);
|
||
fprintf (dump_file, "\n\toffset from base address: ");
|
||
print_generic_expr (dump_file, DR_OFFSET (dr), TDF_SLIM);
|
||
fprintf (dump_file, "\n\tconstant offset from base address: ");
|
||
print_generic_expr (dump_file, DR_INIT (dr), TDF_SLIM);
|
||
fprintf (dump_file, "\n\tbase_object: ");
|
||
print_generic_expr (dump_file, DR_BASE_OBJECT (dr), TDF_SLIM);
|
||
fprintf (dump_file, "\n\tstep: ");
|
||
print_generic_expr (dump_file, DR_STEP (dr), TDF_SLIM);
|
||
fprintf (dump_file, "B\n\tmisalignment from base: ");
|
||
print_generic_expr (dump_file, DR_OFFSET_MISALIGNMENT (dr), TDF_SLIM);
|
||
if (DR_OFFSET_MISALIGNMENT (dr))
|
||
fprintf (dump_file, "B");
|
||
if (DR_ALIGNED_TO (dr))
|
||
{
|
||
fprintf (dump_file, "\n\taligned to: ");
|
||
print_generic_expr (dump_file, DR_ALIGNED_TO (dr), TDF_SLIM);
|
||
}
|
||
fprintf (dump_file, "\n\tmemtag: ");
|
||
print_generic_expr (dump_file, DR_MEMTAG (dr), TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
if (pi && pi->name_mem_tag)
|
||
{
|
||
fprintf (dump_file, "\n\tnametag: ");
|
||
print_generic_expr (dump_file, pi->name_mem_tag, TDF_SLIM);
|
||
fprintf (dump_file, "\n");
|
||
}
|
||
}
|
||
return dr;
|
||
}
|
||
|
||
|
||
/* Returns true when all the functions of a tree_vec CHREC are the
|
||
same. */
|
||
|
||
static bool
|
||
all_chrecs_equal_p (tree chrec)
|
||
{
|
||
int j;
|
||
|
||
for (j = 0; j < TREE_VEC_LENGTH (chrec) - 1; j++)
|
||
if (!eq_evolutions_p (TREE_VEC_ELT (chrec, j),
|
||
TREE_VEC_ELT (chrec, j + 1)))
|
||
return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Determine for each subscript in the data dependence relation DDR
|
||
the distance. */
|
||
|
||
static void
|
||
compute_subscript_distance (struct data_dependence_relation *ddr)
|
||
{
|
||
if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
|
||
{
|
||
unsigned int i;
|
||
|
||
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
|
||
{
|
||
tree conflicts_a, conflicts_b, difference;
|
||
struct subscript *subscript;
|
||
|
||
subscript = DDR_SUBSCRIPT (ddr, i);
|
||
conflicts_a = SUB_CONFLICTS_IN_A (subscript);
|
||
conflicts_b = SUB_CONFLICTS_IN_B (subscript);
|
||
|
||
if (TREE_CODE (conflicts_a) == TREE_VEC)
|
||
{
|
||
if (!all_chrecs_equal_p (conflicts_a))
|
||
{
|
||
SUB_DISTANCE (subscript) = chrec_dont_know;
|
||
return;
|
||
}
|
||
else
|
||
conflicts_a = TREE_VEC_ELT (conflicts_a, 0);
|
||
}
|
||
|
||
if (TREE_CODE (conflicts_b) == TREE_VEC)
|
||
{
|
||
if (!all_chrecs_equal_p (conflicts_b))
|
||
{
|
||
SUB_DISTANCE (subscript) = chrec_dont_know;
|
||
return;
|
||
}
|
||
else
|
||
conflicts_b = TREE_VEC_ELT (conflicts_b, 0);
|
||
}
|
||
|
||
conflicts_b = chrec_convert (integer_type_node, conflicts_b,
|
||
NULL_TREE);
|
||
conflicts_a = chrec_convert (integer_type_node, conflicts_a,
|
||
NULL_TREE);
|
||
difference = chrec_fold_minus
|
||
(integer_type_node, conflicts_b, conflicts_a);
|
||
|
||
if (evolution_function_is_constant_p (difference))
|
||
SUB_DISTANCE (subscript) = difference;
|
||
|
||
else
|
||
SUB_DISTANCE (subscript) = chrec_dont_know;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Initialize a data dependence relation between data accesses A and
|
||
B. NB_LOOPS is the number of loops surrounding the references: the
|
||
size of the classic distance/direction vectors. */
|
||
|
||
static struct data_dependence_relation *
|
||
initialize_data_dependence_relation (struct data_reference *a,
|
||
struct data_reference *b,
|
||
VEC (loop_p, heap) *loop_nest)
|
||
{
|
||
struct data_dependence_relation *res;
|
||
bool differ_p, known_dependence;
|
||
unsigned int i;
|
||
|
||
res = XNEW (struct data_dependence_relation);
|
||
DDR_A (res) = a;
|
||
DDR_B (res) = b;
|
||
DDR_LOOP_NEST (res) = NULL;
|
||
|
||
if (a == NULL || b == NULL)
|
||
{
|
||
DDR_ARE_DEPENDENT (res) = chrec_dont_know;
|
||
return res;
|
||
}
|
||
|
||
/* When A and B are arrays and their dimensions differ, we directly
|
||
initialize the relation to "there is no dependence": chrec_known. */
|
||
if (DR_BASE_OBJECT (a) && DR_BASE_OBJECT (b)
|
||
&& DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b))
|
||
{
|
||
DDR_ARE_DEPENDENT (res) = chrec_known;
|
||
return res;
|
||
}
|
||
|
||
if (DR_BASE_ADDRESS (a) && DR_BASE_ADDRESS (b))
|
||
known_dependence = base_addr_differ_p (a, b, &differ_p);
|
||
else
|
||
known_dependence = base_object_differ_p (a, b, &differ_p);
|
||
|
||
if (!known_dependence)
|
||
{
|
||
/* Can't determine whether the data-refs access the same memory
|
||
region. */
|
||
DDR_ARE_DEPENDENT (res) = chrec_dont_know;
|
||
return res;
|
||
}
|
||
|
||
if (differ_p)
|
||
{
|
||
DDR_ARE_DEPENDENT (res) = chrec_known;
|
||
return res;
|
||
}
|
||
|
||
DDR_AFFINE_P (res) = true;
|
||
DDR_ARE_DEPENDENT (res) = NULL_TREE;
|
||
DDR_SUBSCRIPTS (res) = VEC_alloc (subscript_p, heap, DR_NUM_DIMENSIONS (a));
|
||
DDR_LOOP_NEST (res) = loop_nest;
|
||
DDR_DIR_VECTS (res) = NULL;
|
||
DDR_DIST_VECTS (res) = NULL;
|
||
|
||
for (i = 0; i < DR_NUM_DIMENSIONS (a); i++)
|
||
{
|
||
struct subscript *subscript;
|
||
|
||
subscript = XNEW (struct subscript);
|
||
SUB_CONFLICTS_IN_A (subscript) = chrec_dont_know;
|
||
SUB_CONFLICTS_IN_B (subscript) = chrec_dont_know;
|
||
SUB_LAST_CONFLICT (subscript) = chrec_dont_know;
|
||
SUB_DISTANCE (subscript) = chrec_dont_know;
|
||
VEC_safe_push (subscript_p, heap, DDR_SUBSCRIPTS (res), subscript);
|
||
}
|
||
|
||
return res;
|
||
}
|
||
|
||
/* Set DDR_ARE_DEPENDENT to CHREC and finalize the subscript overlap
|
||
description. */
|
||
|
||
static inline void
|
||
finalize_ddr_dependent (struct data_dependence_relation *ddr,
|
||
tree chrec)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "(dependence classified: ");
|
||
print_generic_expr (dump_file, chrec, 0);
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
DDR_ARE_DEPENDENT (ddr) = chrec;
|
||
VEC_free (subscript_p, heap, DDR_SUBSCRIPTS (ddr));
|
||
}
|
||
|
||
/* The dependence relation DDR cannot be represented by a distance
|
||
vector. */
|
||
|
||
static inline void
|
||
non_affine_dependence_relation (struct data_dependence_relation *ddr)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "(Dependence relation cannot be represented by distance vector.) \n");
|
||
|
||
DDR_AFFINE_P (ddr) = false;
|
||
}
|
||
|
||
|
||
|
||
/* This section contains the classic Banerjee tests. */
|
||
|
||
/* Returns true iff CHREC_A and CHREC_B are not dependent on any index
|
||
variables, i.e., if the ZIV (Zero Index Variable) test is true. */
|
||
|
||
static inline bool
|
||
ziv_subscript_p (tree chrec_a,
|
||
tree chrec_b)
|
||
{
|
||
return (evolution_function_is_constant_p (chrec_a)
|
||
&& evolution_function_is_constant_p (chrec_b));
|
||
}
|
||
|
||
/* Returns true iff CHREC_A and CHREC_B are dependent on an index
|
||
variable, i.e., if the SIV (Single Index Variable) test is true. */
|
||
|
||
static bool
|
||
siv_subscript_p (tree chrec_a,
|
||
tree chrec_b)
|
||
{
|
||
if ((evolution_function_is_constant_p (chrec_a)
|
||
&& evolution_function_is_univariate_p (chrec_b))
|
||
|| (evolution_function_is_constant_p (chrec_b)
|
||
&& evolution_function_is_univariate_p (chrec_a)))
|
||
return true;
|
||
|
||
if (evolution_function_is_univariate_p (chrec_a)
|
||
&& evolution_function_is_univariate_p (chrec_b))
|
||
{
|
||
switch (TREE_CODE (chrec_a))
|
||
{
|
||
case POLYNOMIAL_CHREC:
|
||
switch (TREE_CODE (chrec_b))
|
||
{
|
||
case POLYNOMIAL_CHREC:
|
||
if (CHREC_VARIABLE (chrec_a) != CHREC_VARIABLE (chrec_b))
|
||
return false;
|
||
|
||
default:
|
||
return true;
|
||
}
|
||
|
||
default:
|
||
return true;
|
||
}
|
||
}
|
||
|
||
return false;
|
||
}
|
||
|
||
/* Analyze a ZIV (Zero Index Variable) subscript. *OVERLAPS_A and
|
||
*OVERLAPS_B are initialized to the functions that describe the
|
||
relation between the elements accessed twice by CHREC_A and
|
||
CHREC_B. For k >= 0, the following property is verified:
|
||
|
||
CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */
|
||
|
||
static void
|
||
analyze_ziv_subscript (tree chrec_a,
|
||
tree chrec_b,
|
||
tree *overlaps_a,
|
||
tree *overlaps_b,
|
||
tree *last_conflicts)
|
||
{
|
||
tree difference;
|
||
dependence_stats.num_ziv++;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "(analyze_ziv_subscript \n");
|
||
|
||
chrec_a = chrec_convert (integer_type_node, chrec_a, NULL_TREE);
|
||
chrec_b = chrec_convert (integer_type_node, chrec_b, NULL_TREE);
|
||
difference = chrec_fold_minus (integer_type_node, chrec_a, chrec_b);
|
||
|
||
switch (TREE_CODE (difference))
|
||
{
|
||
case INTEGER_CST:
|
||
if (integer_zerop (difference))
|
||
{
|
||
/* The difference is equal to zero: the accessed index
|
||
overlaps for each iteration in the loop. */
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = integer_zero_node;
|
||
*last_conflicts = chrec_dont_know;
|
||
dependence_stats.num_ziv_dependent++;
|
||
}
|
||
else
|
||
{
|
||
/* The accesses do not overlap. */
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_ziv_independent++;
|
||
}
|
||
break;
|
||
|
||
default:
|
||
/* We're not sure whether the indexes overlap. For the moment,
|
||
conservatively answer "don't know". */
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "ziv test failed: difference is non-integer.\n");
|
||
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
dependence_stats.num_ziv_unimplemented++;
|
||
break;
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
/* Get the real or estimated number of iterations for LOOPNUM, whichever is
|
||
available. Return the number of iterations as a tree, or NULL_TREE if
|
||
we don't know. */
|
||
|
||
static tree
|
||
get_number_of_iters_for_loop (int loopnum)
|
||
{
|
||
tree numiter = number_of_iterations_in_loop (current_loops->parray[loopnum]);
|
||
|
||
if (TREE_CODE (numiter) != INTEGER_CST)
|
||
numiter = current_loops->parray[loopnum]->estimated_nb_iterations;
|
||
if (chrec_contains_undetermined (numiter))
|
||
return NULL_TREE;
|
||
return numiter;
|
||
}
|
||
|
||
/* Analyze a SIV (Single Index Variable) subscript where CHREC_A is a
|
||
constant, and CHREC_B is an affine function. *OVERLAPS_A and
|
||
*OVERLAPS_B are initialized to the functions that describe the
|
||
relation between the elements accessed twice by CHREC_A and
|
||
CHREC_B. For k >= 0, the following property is verified:
|
||
|
||
CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */
|
||
|
||
static void
|
||
analyze_siv_subscript_cst_affine (tree chrec_a,
|
||
tree chrec_b,
|
||
tree *overlaps_a,
|
||
tree *overlaps_b,
|
||
tree *last_conflicts)
|
||
{
|
||
bool value0, value1, value2;
|
||
tree difference;
|
||
|
||
chrec_a = chrec_convert (integer_type_node, chrec_a, NULL_TREE);
|
||
chrec_b = chrec_convert (integer_type_node, chrec_b, NULL_TREE);
|
||
difference = chrec_fold_minus
|
||
(integer_type_node, initial_condition (chrec_b), chrec_a);
|
||
|
||
if (!chrec_is_positive (initial_condition (difference), &value0))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "siv test failed: chrec is not positive.\n");
|
||
|
||
dependence_stats.num_siv_unimplemented++;
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
if (value0 == false)
|
||
{
|
||
if (!chrec_is_positive (CHREC_RIGHT (chrec_b), &value1))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "siv test failed: chrec not positive.\n");
|
||
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
dependence_stats.num_siv_unimplemented++;
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
if (value1 == true)
|
||
{
|
||
/* Example:
|
||
chrec_a = 12
|
||
chrec_b = {10, +, 1}
|
||
*/
|
||
|
||
if (tree_fold_divides_p (CHREC_RIGHT (chrec_b), difference))
|
||
{
|
||
tree numiter;
|
||
int loopnum = CHREC_VARIABLE (chrec_b);
|
||
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = fold_build2 (EXACT_DIV_EXPR, integer_type_node,
|
||
fold_build1 (ABS_EXPR,
|
||
integer_type_node,
|
||
difference),
|
||
CHREC_RIGHT (chrec_b));
|
||
*last_conflicts = integer_one_node;
|
||
|
||
|
||
/* Perform weak-zero siv test to see if overlap is
|
||
outside the loop bounds. */
|
||
numiter = get_number_of_iters_for_loop (loopnum);
|
||
|
||
if (numiter != NULL_TREE
|
||
&& TREE_CODE (*overlaps_b) == INTEGER_CST
|
||
&& tree_int_cst_lt (numiter, *overlaps_b))
|
||
{
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_siv_independent++;
|
||
return;
|
||
}
|
||
dependence_stats.num_siv_dependent++;
|
||
return;
|
||
}
|
||
|
||
/* When the step does not divide the difference, there are
|
||
no overlaps. */
|
||
else
|
||
{
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_siv_independent++;
|
||
return;
|
||
}
|
||
}
|
||
|
||
else
|
||
{
|
||
/* Example:
|
||
chrec_a = 12
|
||
chrec_b = {10, +, -1}
|
||
|
||
In this case, chrec_a will not overlap with chrec_b. */
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_siv_independent++;
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (!chrec_is_positive (CHREC_RIGHT (chrec_b), &value2))
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "siv test failed: chrec not positive.\n");
|
||
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
dependence_stats.num_siv_unimplemented++;
|
||
return;
|
||
}
|
||
else
|
||
{
|
||
if (value2 == false)
|
||
{
|
||
/* Example:
|
||
chrec_a = 3
|
||
chrec_b = {10, +, -1}
|
||
*/
|
||
if (tree_fold_divides_p (CHREC_RIGHT (chrec_b), difference))
|
||
{
|
||
tree numiter;
|
||
int loopnum = CHREC_VARIABLE (chrec_b);
|
||
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = fold_build2 (EXACT_DIV_EXPR,
|
||
integer_type_node, difference,
|
||
CHREC_RIGHT (chrec_b));
|
||
*last_conflicts = integer_one_node;
|
||
|
||
/* Perform weak-zero siv test to see if overlap is
|
||
outside the loop bounds. */
|
||
numiter = get_number_of_iters_for_loop (loopnum);
|
||
|
||
if (numiter != NULL_TREE
|
||
&& TREE_CODE (*overlaps_b) == INTEGER_CST
|
||
&& tree_int_cst_lt (numiter, *overlaps_b))
|
||
{
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_siv_independent++;
|
||
return;
|
||
}
|
||
dependence_stats.num_siv_dependent++;
|
||
return;
|
||
}
|
||
|
||
/* When the step does not divide the difference, there
|
||
are no overlaps. */
|
||
else
|
||
{
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_siv_independent++;
|
||
return;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Example:
|
||
chrec_a = 3
|
||
chrec_b = {4, +, 1}
|
||
|
||
In this case, chrec_a will not overlap with chrec_b. */
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_siv_independent++;
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Helper recursive function for initializing the matrix A. Returns
|
||
the initial value of CHREC. */
|
||
|
||
static int
|
||
initialize_matrix_A (lambda_matrix A, tree chrec, unsigned index, int mult)
|
||
{
|
||
gcc_assert (chrec);
|
||
|
||
if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
|
||
return int_cst_value (chrec);
|
||
|
||
A[index][0] = mult * int_cst_value (CHREC_RIGHT (chrec));
|
||
return initialize_matrix_A (A, CHREC_LEFT (chrec), index + 1, mult);
|
||
}
|
||
|
||
#define FLOOR_DIV(x,y) ((x) / (y))
|
||
|
||
/* Solves the special case of the Diophantine equation:
|
||
| {0, +, STEP_A}_x (OVERLAPS_A) = {0, +, STEP_B}_y (OVERLAPS_B)
|
||
|
||
Computes the descriptions OVERLAPS_A and OVERLAPS_B. NITER is the
|
||
number of iterations that loops X and Y run. The overlaps will be
|
||
constructed as evolutions in dimension DIM. */
|
||
|
||
static void
|
||
compute_overlap_steps_for_affine_univar (int niter, int step_a, int step_b,
|
||
tree *overlaps_a, tree *overlaps_b,
|
||
tree *last_conflicts, int dim)
|
||
{
|
||
if (((step_a > 0 && step_b > 0)
|
||
|| (step_a < 0 && step_b < 0)))
|
||
{
|
||
int step_overlaps_a, step_overlaps_b;
|
||
int gcd_steps_a_b, last_conflict, tau2;
|
||
|
||
gcd_steps_a_b = gcd (step_a, step_b);
|
||
step_overlaps_a = step_b / gcd_steps_a_b;
|
||
step_overlaps_b = step_a / gcd_steps_a_b;
|
||
|
||
tau2 = FLOOR_DIV (niter, step_overlaps_a);
|
||
tau2 = MIN (tau2, FLOOR_DIV (niter, step_overlaps_b));
|
||
last_conflict = tau2;
|
||
|
||
*overlaps_a = build_polynomial_chrec
|
||
(dim, integer_zero_node,
|
||
build_int_cst (NULL_TREE, step_overlaps_a));
|
||
*overlaps_b = build_polynomial_chrec
|
||
(dim, integer_zero_node,
|
||
build_int_cst (NULL_TREE, step_overlaps_b));
|
||
*last_conflicts = build_int_cst (NULL_TREE, last_conflict);
|
||
}
|
||
|
||
else
|
||
{
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = integer_zero_node;
|
||
*last_conflicts = integer_zero_node;
|
||
}
|
||
}
|
||
|
||
|
||
/* Solves the special case of a Diophantine equation where CHREC_A is
|
||
an affine bivariate function, and CHREC_B is an affine univariate
|
||
function. For example,
|
||
|
||
| {{0, +, 1}_x, +, 1335}_y = {0, +, 1336}_z
|
||
|
||
has the following overlapping functions:
|
||
|
||
| x (t, u, v) = {{0, +, 1336}_t, +, 1}_v
|
||
| y (t, u, v) = {{0, +, 1336}_u, +, 1}_v
|
||
| z (t, u, v) = {{{0, +, 1}_t, +, 1335}_u, +, 1}_v
|
||
|
||
FORNOW: This is a specialized implementation for a case occurring in
|
||
a common benchmark. Implement the general algorithm. */
|
||
|
||
static void
|
||
compute_overlap_steps_for_affine_1_2 (tree chrec_a, tree chrec_b,
|
||
tree *overlaps_a, tree *overlaps_b,
|
||
tree *last_conflicts)
|
||
{
|
||
bool xz_p, yz_p, xyz_p;
|
||
int step_x, step_y, step_z;
|
||
int niter_x, niter_y, niter_z, niter;
|
||
tree numiter_x, numiter_y, numiter_z;
|
||
tree overlaps_a_xz, overlaps_b_xz, last_conflicts_xz;
|
||
tree overlaps_a_yz, overlaps_b_yz, last_conflicts_yz;
|
||
tree overlaps_a_xyz, overlaps_b_xyz, last_conflicts_xyz;
|
||
|
||
step_x = int_cst_value (CHREC_RIGHT (CHREC_LEFT (chrec_a)));
|
||
step_y = int_cst_value (CHREC_RIGHT (chrec_a));
|
||
step_z = int_cst_value (CHREC_RIGHT (chrec_b));
|
||
|
||
numiter_x = get_number_of_iters_for_loop (CHREC_VARIABLE (CHREC_LEFT (chrec_a)));
|
||
numiter_y = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a));
|
||
numiter_z = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_b));
|
||
|
||
if (numiter_x == NULL_TREE || numiter_y == NULL_TREE
|
||
|| numiter_z == NULL_TREE)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "overlap steps test failed: no iteration counts.\n");
|
||
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
return;
|
||
}
|
||
|
||
niter_x = int_cst_value (numiter_x);
|
||
niter_y = int_cst_value (numiter_y);
|
||
niter_z = int_cst_value (numiter_z);
|
||
|
||
niter = MIN (niter_x, niter_z);
|
||
compute_overlap_steps_for_affine_univar (niter, step_x, step_z,
|
||
&overlaps_a_xz,
|
||
&overlaps_b_xz,
|
||
&last_conflicts_xz, 1);
|
||
niter = MIN (niter_y, niter_z);
|
||
compute_overlap_steps_for_affine_univar (niter, step_y, step_z,
|
||
&overlaps_a_yz,
|
||
&overlaps_b_yz,
|
||
&last_conflicts_yz, 2);
|
||
niter = MIN (niter_x, niter_z);
|
||
niter = MIN (niter_y, niter);
|
||
compute_overlap_steps_for_affine_univar (niter, step_x + step_y, step_z,
|
||
&overlaps_a_xyz,
|
||
&overlaps_b_xyz,
|
||
&last_conflicts_xyz, 3);
|
||
|
||
xz_p = !integer_zerop (last_conflicts_xz);
|
||
yz_p = !integer_zerop (last_conflicts_yz);
|
||
xyz_p = !integer_zerop (last_conflicts_xyz);
|
||
|
||
if (xz_p || yz_p || xyz_p)
|
||
{
|
||
*overlaps_a = make_tree_vec (2);
|
||
TREE_VEC_ELT (*overlaps_a, 0) = integer_zero_node;
|
||
TREE_VEC_ELT (*overlaps_a, 1) = integer_zero_node;
|
||
*overlaps_b = integer_zero_node;
|
||
if (xz_p)
|
||
{
|
||
tree t0 = chrec_convert (integer_type_node,
|
||
TREE_VEC_ELT (*overlaps_a, 0), NULL_TREE);
|
||
tree t1 = chrec_convert (integer_type_node, overlaps_a_xz,
|
||
NULL_TREE);
|
||
tree t2 = chrec_convert (integer_type_node, *overlaps_b,
|
||
NULL_TREE);
|
||
tree t3 = chrec_convert (integer_type_node, overlaps_b_xz,
|
||
NULL_TREE);
|
||
|
||
TREE_VEC_ELT (*overlaps_a, 0) = chrec_fold_plus (integer_type_node,
|
||
t0, t1);
|
||
*overlaps_b = chrec_fold_plus (integer_type_node, t2, t3);
|
||
*last_conflicts = last_conflicts_xz;
|
||
}
|
||
if (yz_p)
|
||
{
|
||
tree t0 = chrec_convert (integer_type_node,
|
||
TREE_VEC_ELT (*overlaps_a, 1), NULL_TREE);
|
||
tree t1 = chrec_convert (integer_type_node, overlaps_a_yz, NULL_TREE);
|
||
tree t2 = chrec_convert (integer_type_node, *overlaps_b, NULL_TREE);
|
||
tree t3 = chrec_convert (integer_type_node, overlaps_b_yz, NULL_TREE);
|
||
|
||
TREE_VEC_ELT (*overlaps_a, 1) = chrec_fold_plus (integer_type_node,
|
||
t0, t1);
|
||
*overlaps_b = chrec_fold_plus (integer_type_node, t2, t3);
|
||
*last_conflicts = last_conflicts_yz;
|
||
}
|
||
if (xyz_p)
|
||
{
|
||
tree t0 = chrec_convert (integer_type_node,
|
||
TREE_VEC_ELT (*overlaps_a, 0), NULL_TREE);
|
||
tree t1 = chrec_convert (integer_type_node, overlaps_a_xyz,
|
||
NULL_TREE);
|
||
tree t2 = chrec_convert (integer_type_node,
|
||
TREE_VEC_ELT (*overlaps_a, 1), NULL_TREE);
|
||
tree t3 = chrec_convert (integer_type_node, overlaps_a_xyz,
|
||
NULL_TREE);
|
||
tree t4 = chrec_convert (integer_type_node, *overlaps_b, NULL_TREE);
|
||
tree t5 = chrec_convert (integer_type_node, overlaps_b_xyz,
|
||
NULL_TREE);
|
||
|
||
TREE_VEC_ELT (*overlaps_a, 0) = chrec_fold_plus (integer_type_node,
|
||
t0, t1);
|
||
TREE_VEC_ELT (*overlaps_a, 1) = chrec_fold_plus (integer_type_node,
|
||
t2, t3);
|
||
*overlaps_b = chrec_fold_plus (integer_type_node, t4, t5);
|
||
*last_conflicts = last_conflicts_xyz;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = integer_zero_node;
|
||
*last_conflicts = integer_zero_node;
|
||
}
|
||
}
|
||
|
||
/* Determines the overlapping elements due to accesses CHREC_A and
|
||
CHREC_B, that are affine functions. This function cannot handle
|
||
symbolic evolution functions, ie. when initial conditions are
|
||
parameters, because it uses lambda matrices of integers. */
|
||
|
||
static void
|
||
analyze_subscript_affine_affine (tree chrec_a,
|
||
tree chrec_b,
|
||
tree *overlaps_a,
|
||
tree *overlaps_b,
|
||
tree *last_conflicts)
|
||
{
|
||
unsigned nb_vars_a, nb_vars_b, dim;
|
||
int init_a, init_b, gamma, gcd_alpha_beta;
|
||
int tau1, tau2;
|
||
lambda_matrix A, U, S;
|
||
|
||
if (eq_evolutions_p (chrec_a, chrec_b))
|
||
{
|
||
/* The accessed index overlaps for each iteration in the
|
||
loop. */
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = integer_zero_node;
|
||
*last_conflicts = chrec_dont_know;
|
||
return;
|
||
}
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "(analyze_subscript_affine_affine \n");
|
||
|
||
/* For determining the initial intersection, we have to solve a
|
||
Diophantine equation. This is the most time consuming part.
|
||
|
||
For answering to the question: "Is there a dependence?" we have
|
||
to prove that there exists a solution to the Diophantine
|
||
equation, and that the solution is in the iteration domain,
|
||
i.e. the solution is positive or zero, and that the solution
|
||
happens before the upper bound loop.nb_iterations. Otherwise
|
||
there is no dependence. This function outputs a description of
|
||
the iterations that hold the intersections. */
|
||
|
||
nb_vars_a = nb_vars_in_chrec (chrec_a);
|
||
nb_vars_b = nb_vars_in_chrec (chrec_b);
|
||
|
||
dim = nb_vars_a + nb_vars_b;
|
||
U = lambda_matrix_new (dim, dim);
|
||
A = lambda_matrix_new (dim, 1);
|
||
S = lambda_matrix_new (dim, 1);
|
||
|
||
init_a = initialize_matrix_A (A, chrec_a, 0, 1);
|
||
init_b = initialize_matrix_A (A, chrec_b, nb_vars_a, -1);
|
||
gamma = init_b - init_a;
|
||
|
||
/* Don't do all the hard work of solving the Diophantine equation
|
||
when we already know the solution: for example,
|
||
| {3, +, 1}_1
|
||
| {3, +, 4}_2
|
||
| gamma = 3 - 3 = 0.
|
||
Then the first overlap occurs during the first iterations:
|
||
| {3, +, 1}_1 ({0, +, 4}_x) = {3, +, 4}_2 ({0, +, 1}_x)
|
||
*/
|
||
if (gamma == 0)
|
||
{
|
||
if (nb_vars_a == 1 && nb_vars_b == 1)
|
||
{
|
||
int step_a, step_b;
|
||
int niter, niter_a, niter_b;
|
||
tree numiter_a, numiter_b;
|
||
|
||
numiter_a = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a));
|
||
numiter_b = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_b));
|
||
if (numiter_a == NULL_TREE || numiter_b == NULL_TREE)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: missing iteration counts.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
goto end_analyze_subs_aa;
|
||
}
|
||
|
||
niter_a = int_cst_value (numiter_a);
|
||
niter_b = int_cst_value (numiter_b);
|
||
niter = MIN (niter_a, niter_b);
|
||
|
||
step_a = int_cst_value (CHREC_RIGHT (chrec_a));
|
||
step_b = int_cst_value (CHREC_RIGHT (chrec_b));
|
||
|
||
compute_overlap_steps_for_affine_univar (niter, step_a, step_b,
|
||
overlaps_a, overlaps_b,
|
||
last_conflicts, 1);
|
||
}
|
||
|
||
else if (nb_vars_a == 2 && nb_vars_b == 1)
|
||
compute_overlap_steps_for_affine_1_2
|
||
(chrec_a, chrec_b, overlaps_a, overlaps_b, last_conflicts);
|
||
|
||
else if (nb_vars_a == 1 && nb_vars_b == 2)
|
||
compute_overlap_steps_for_affine_1_2
|
||
(chrec_b, chrec_a, overlaps_b, overlaps_a, last_conflicts);
|
||
|
||
else
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: too many variables.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
}
|
||
goto end_analyze_subs_aa;
|
||
}
|
||
|
||
/* U.A = S */
|
||
lambda_matrix_right_hermite (A, dim, 1, S, U);
|
||
|
||
if (S[0][0] < 0)
|
||
{
|
||
S[0][0] *= -1;
|
||
lambda_matrix_row_negate (U, dim, 0);
|
||
}
|
||
gcd_alpha_beta = S[0][0];
|
||
|
||
/* Something went wrong: for example in {1, +, 0}_5 vs. {0, +, 0}_5,
|
||
but that is a quite strange case. Instead of ICEing, answer
|
||
don't know. */
|
||
if (gcd_alpha_beta == 0)
|
||
{
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
goto end_analyze_subs_aa;
|
||
}
|
||
|
||
/* The classic "gcd-test". */
|
||
if (!int_divides_p (gcd_alpha_beta, gamma))
|
||
{
|
||
/* The "gcd-test" has determined that there is no integer
|
||
solution, i.e. there is no dependence. */
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
}
|
||
|
||
/* Both access functions are univariate. This includes SIV and MIV cases. */
|
||
else if (nb_vars_a == 1 && nb_vars_b == 1)
|
||
{
|
||
/* Both functions should have the same evolution sign. */
|
||
if (((A[0][0] > 0 && -A[1][0] > 0)
|
||
|| (A[0][0] < 0 && -A[1][0] < 0)))
|
||
{
|
||
/* The solutions are given by:
|
||
|
|
||
| [GAMMA/GCD_ALPHA_BETA t].[u11 u12] = [x0]
|
||
| [u21 u22] [y0]
|
||
|
||
For a given integer t. Using the following variables,
|
||
|
||
| i0 = u11 * gamma / gcd_alpha_beta
|
||
| j0 = u12 * gamma / gcd_alpha_beta
|
||
| i1 = u21
|
||
| j1 = u22
|
||
|
||
the solutions are:
|
||
|
||
| x0 = i0 + i1 * t,
|
||
| y0 = j0 + j1 * t. */
|
||
|
||
int i0, j0, i1, j1;
|
||
|
||
/* X0 and Y0 are the first iterations for which there is a
|
||
dependence. X0, Y0 are two solutions of the Diophantine
|
||
equation: chrec_a (X0) = chrec_b (Y0). */
|
||
int x0, y0;
|
||
int niter, niter_a, niter_b;
|
||
tree numiter_a, numiter_b;
|
||
|
||
numiter_a = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a));
|
||
numiter_b = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_b));
|
||
|
||
if (numiter_a == NULL_TREE || numiter_b == NULL_TREE)
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: missing iteration counts.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
goto end_analyze_subs_aa;
|
||
}
|
||
|
||
niter_a = int_cst_value (numiter_a);
|
||
niter_b = int_cst_value (numiter_b);
|
||
niter = MIN (niter_a, niter_b);
|
||
|
||
i0 = U[0][0] * gamma / gcd_alpha_beta;
|
||
j0 = U[0][1] * gamma / gcd_alpha_beta;
|
||
i1 = U[1][0];
|
||
j1 = U[1][1];
|
||
|
||
if ((i1 == 0 && i0 < 0)
|
||
|| (j1 == 0 && j0 < 0))
|
||
{
|
||
/* There is no solution.
|
||
FIXME: The case "i0 > nb_iterations, j0 > nb_iterations"
|
||
falls in here, but for the moment we don't look at the
|
||
upper bound of the iteration domain. */
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
}
|
||
|
||
else
|
||
{
|
||
if (i1 > 0)
|
||
{
|
||
tau1 = CEIL (-i0, i1);
|
||
tau2 = FLOOR_DIV (niter - i0, i1);
|
||
|
||
if (j1 > 0)
|
||
{
|
||
int last_conflict, min_multiple;
|
||
tau1 = MAX (tau1, CEIL (-j0, j1));
|
||
tau2 = MIN (tau2, FLOOR_DIV (niter - j0, j1));
|
||
|
||
x0 = i1 * tau1 + i0;
|
||
y0 = j1 * tau1 + j0;
|
||
|
||
/* At this point (x0, y0) is one of the
|
||
solutions to the Diophantine equation. The
|
||
next step has to compute the smallest
|
||
positive solution: the first conflicts. */
|
||
min_multiple = MIN (x0 / i1, y0 / j1);
|
||
x0 -= i1 * min_multiple;
|
||
y0 -= j1 * min_multiple;
|
||
|
||
tau1 = (x0 - i0)/i1;
|
||
last_conflict = tau2 - tau1;
|
||
|
||
/* If the overlap occurs outside of the bounds of the
|
||
loop, there is no dependence. */
|
||
if (x0 > niter || y0 > niter)
|
||
{
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
}
|
||
else
|
||
{
|
||
*overlaps_a = build_polynomial_chrec
|
||
(1,
|
||
build_int_cst (NULL_TREE, x0),
|
||
build_int_cst (NULL_TREE, i1));
|
||
*overlaps_b = build_polynomial_chrec
|
||
(1,
|
||
build_int_cst (NULL_TREE, y0),
|
||
build_int_cst (NULL_TREE, j1));
|
||
*last_conflicts = build_int_cst (NULL_TREE, last_conflict);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* FIXME: For the moment, the upper bound of the
|
||
iteration domain for j is not checked. */
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: unimplemented.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
}
|
||
}
|
||
|
||
else
|
||
{
|
||
/* FIXME: For the moment, the upper bound of the
|
||
iteration domain for i is not checked. */
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: unimplemented.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: unimplemented.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
}
|
||
}
|
||
|
||
else
|
||
{
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "affine-affine test failed: unimplemented.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
}
|
||
|
||
end_analyze_subs_aa:
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, " (overlaps_a = ");
|
||
print_generic_expr (dump_file, *overlaps_a, 0);
|
||
fprintf (dump_file, ")\n (overlaps_b = ");
|
||
print_generic_expr (dump_file, *overlaps_b, 0);
|
||
fprintf (dump_file, ")\n");
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
}
|
||
|
||
/* Returns true when analyze_subscript_affine_affine can be used for
|
||
determining the dependence relation between chrec_a and chrec_b,
|
||
that contain symbols. This function modifies chrec_a and chrec_b
|
||
such that the analysis result is the same, and such that they don't
|
||
contain symbols, and then can safely be passed to the analyzer.
|
||
|
||
Example: The analysis of the following tuples of evolutions produce
|
||
the same results: {x+1, +, 1}_1 vs. {x+3, +, 1}_1, and {-2, +, 1}_1
|
||
vs. {0, +, 1}_1
|
||
|
||
{x+1, +, 1}_1 ({2, +, 1}_1) = {x+3, +, 1}_1 ({0, +, 1}_1)
|
||
{-2, +, 1}_1 ({2, +, 1}_1) = {0, +, 1}_1 ({0, +, 1}_1)
|
||
*/
|
||
|
||
static bool
|
||
can_use_analyze_subscript_affine_affine (tree *chrec_a, tree *chrec_b)
|
||
{
|
||
tree diff, type, left_a, left_b, right_b;
|
||
|
||
if (chrec_contains_symbols (CHREC_RIGHT (*chrec_a))
|
||
|| chrec_contains_symbols (CHREC_RIGHT (*chrec_b)))
|
||
/* FIXME: For the moment not handled. Might be refined later. */
|
||
return false;
|
||
|
||
type = chrec_type (*chrec_a);
|
||
left_a = CHREC_LEFT (*chrec_a);
|
||
left_b = chrec_convert (type, CHREC_LEFT (*chrec_b), NULL_TREE);
|
||
diff = chrec_fold_minus (type, left_a, left_b);
|
||
|
||
if (!evolution_function_is_constant_p (diff))
|
||
return false;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "can_use_subscript_aff_aff_for_symbolic \n");
|
||
|
||
*chrec_a = build_polynomial_chrec (CHREC_VARIABLE (*chrec_a),
|
||
diff, CHREC_RIGHT (*chrec_a));
|
||
right_b = chrec_convert (type, CHREC_RIGHT (*chrec_b), NULL_TREE);
|
||
*chrec_b = build_polynomial_chrec (CHREC_VARIABLE (*chrec_b),
|
||
build_int_cst (type, 0),
|
||
right_b);
|
||
return true;
|
||
}
|
||
|
||
/* Analyze a SIV (Single Index Variable) subscript. *OVERLAPS_A and
|
||
*OVERLAPS_B are initialized to the functions that describe the
|
||
relation between the elements accessed twice by CHREC_A and
|
||
CHREC_B. For k >= 0, the following property is verified:
|
||
|
||
CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */
|
||
|
||
static void
|
||
analyze_siv_subscript (tree chrec_a,
|
||
tree chrec_b,
|
||
tree *overlaps_a,
|
||
tree *overlaps_b,
|
||
tree *last_conflicts)
|
||
{
|
||
dependence_stats.num_siv++;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "(analyze_siv_subscript \n");
|
||
|
||
if (evolution_function_is_constant_p (chrec_a)
|
||
&& evolution_function_is_affine_p (chrec_b))
|
||
analyze_siv_subscript_cst_affine (chrec_a, chrec_b,
|
||
overlaps_a, overlaps_b, last_conflicts);
|
||
|
||
else if (evolution_function_is_affine_p (chrec_a)
|
||
&& evolution_function_is_constant_p (chrec_b))
|
||
analyze_siv_subscript_cst_affine (chrec_b, chrec_a,
|
||
overlaps_b, overlaps_a, last_conflicts);
|
||
|
||
else if (evolution_function_is_affine_p (chrec_a)
|
||
&& evolution_function_is_affine_p (chrec_b))
|
||
{
|
||
if (!chrec_contains_symbols (chrec_a)
|
||
&& !chrec_contains_symbols (chrec_b))
|
||
{
|
||
analyze_subscript_affine_affine (chrec_a, chrec_b,
|
||
overlaps_a, overlaps_b,
|
||
last_conflicts);
|
||
|
||
if (*overlaps_a == chrec_dont_know
|
||
|| *overlaps_b == chrec_dont_know)
|
||
dependence_stats.num_siv_unimplemented++;
|
||
else if (*overlaps_a == chrec_known
|
||
|| *overlaps_b == chrec_known)
|
||
dependence_stats.num_siv_independent++;
|
||
else
|
||
dependence_stats.num_siv_dependent++;
|
||
}
|
||
else if (can_use_analyze_subscript_affine_affine (&chrec_a,
|
||
&chrec_b))
|
||
{
|
||
analyze_subscript_affine_affine (chrec_a, chrec_b,
|
||
overlaps_a, overlaps_b,
|
||
last_conflicts);
|
||
/* FIXME: The number of iterations is a symbolic expression.
|
||
Compute it properly. */
|
||
*last_conflicts = chrec_dont_know;
|
||
|
||
if (*overlaps_a == chrec_dont_know
|
||
|| *overlaps_b == chrec_dont_know)
|
||
dependence_stats.num_siv_unimplemented++;
|
||
else if (*overlaps_a == chrec_known
|
||
|| *overlaps_b == chrec_known)
|
||
dependence_stats.num_siv_independent++;
|
||
else
|
||
dependence_stats.num_siv_dependent++;
|
||
}
|
||
else
|
||
goto siv_subscript_dontknow;
|
||
}
|
||
|
||
else
|
||
{
|
||
siv_subscript_dontknow:;
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "siv test failed: unimplemented.\n");
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
dependence_stats.num_siv_unimplemented++;
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
/* Return true when the property can be computed. RES should contain
|
||
true when calling the first time this function, then it is set to
|
||
false when one of the evolution steps of an affine CHREC does not
|
||
divide the constant CST. */
|
||
|
||
static bool
|
||
chrec_steps_divide_constant_p (tree chrec,
|
||
tree cst,
|
||
bool *res)
|
||
{
|
||
switch (TREE_CODE (chrec))
|
||
{
|
||
case POLYNOMIAL_CHREC:
|
||
if (evolution_function_is_constant_p (CHREC_RIGHT (chrec)))
|
||
{
|
||
if (tree_fold_divides_p (CHREC_RIGHT (chrec), cst))
|
||
/* Keep RES to true, and iterate on other dimensions. */
|
||
return chrec_steps_divide_constant_p (CHREC_LEFT (chrec), cst, res);
|
||
|
||
*res = false;
|
||
return true;
|
||
}
|
||
else
|
||
/* When the step is a parameter the result is undetermined. */
|
||
return false;
|
||
|
||
default:
|
||
/* On the initial condition, return true. */
|
||
return true;
|
||
}
|
||
}
|
||
|
||
/* Analyze a MIV (Multiple Index Variable) subscript. *OVERLAPS_A and
|
||
*OVERLAPS_B are initialized to the functions that describe the
|
||
relation between the elements accessed twice by CHREC_A and
|
||
CHREC_B. For k >= 0, the following property is verified:
|
||
|
||
CHREC_A (*OVERLAPS_A (k)) = CHREC_B (*OVERLAPS_B (k)). */
|
||
|
||
static void
|
||
analyze_miv_subscript (tree chrec_a,
|
||
tree chrec_b,
|
||
tree *overlaps_a,
|
||
tree *overlaps_b,
|
||
tree *last_conflicts)
|
||
{
|
||
/* FIXME: This is a MIV subscript, not yet handled.
|
||
Example: (A[{1, +, 1}_1] vs. A[{1, +, 1}_2]) that comes from
|
||
(A[i] vs. A[j]).
|
||
|
||
In the SIV test we had to solve a Diophantine equation with two
|
||
variables. In the MIV case we have to solve a Diophantine
|
||
equation with 2*n variables (if the subscript uses n IVs).
|
||
*/
|
||
bool divide_p = true;
|
||
tree difference;
|
||
dependence_stats.num_miv++;
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "(analyze_miv_subscript \n");
|
||
|
||
chrec_a = chrec_convert (integer_type_node, chrec_a, NULL_TREE);
|
||
chrec_b = chrec_convert (integer_type_node, chrec_b, NULL_TREE);
|
||
difference = chrec_fold_minus (integer_type_node, chrec_a, chrec_b);
|
||
|
||
if (eq_evolutions_p (chrec_a, chrec_b))
|
||
{
|
||
/* Access functions are the same: all the elements are accessed
|
||
in the same order. */
|
||
*overlaps_a = integer_zero_node;
|
||
*overlaps_b = integer_zero_node;
|
||
*last_conflicts = get_number_of_iters_for_loop (CHREC_VARIABLE (chrec_a));
|
||
dependence_stats.num_miv_dependent++;
|
||
}
|
||
|
||
else if (evolution_function_is_constant_p (difference)
|
||
/* For the moment, the following is verified:
|
||
evolution_function_is_affine_multivariate_p (chrec_a) */
|
||
&& chrec_steps_divide_constant_p (chrec_a, difference, ÷_p)
|
||
&& !divide_p)
|
||
{
|
||
/* testsuite/.../ssa-chrec-33.c
|
||
{{21, +, 2}_1, +, -2}_2 vs. {{20, +, 2}_1, +, -2}_2
|
||
|
||
The difference is 1, and the evolution steps are equal to 2,
|
||
consequently there are no overlapping elements. */
|
||
*overlaps_a = chrec_known;
|
||
*overlaps_b = chrec_known;
|
||
*last_conflicts = integer_zero_node;
|
||
dependence_stats.num_miv_independent++;
|
||
}
|
||
|
||
else if (evolution_function_is_affine_multivariate_p (chrec_a)
|
||
&& !chrec_contains_symbols (chrec_a)
|
||
&& evolution_function_is_affine_multivariate_p (chrec_b)
|
||
&& !chrec_contains_symbols (chrec_b))
|
||
{
|
||
/* testsuite/.../ssa-chrec-35.c
|
||
{0, +, 1}_2 vs. {0, +, 1}_3
|
||
the overlapping elements are respectively located at iterations:
|
||
{0, +, 1}_x and {0, +, 1}_x,
|
||
in other words, we have the equality:
|
||
{0, +, 1}_2 ({0, +, 1}_x) = {0, +, 1}_3 ({0, +, 1}_x)
|
||
|
||
Other examples:
|
||
{{0, +, 1}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) =
|
||
{0, +, 1}_1 ({{0, +, 1}_x, +, 2}_y)
|
||
|
||
{{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) =
|
||
{{0, +, 3}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y)
|
||
*/
|
||
analyze_subscript_affine_affine (chrec_a, chrec_b,
|
||
overlaps_a, overlaps_b, last_conflicts);
|
||
|
||
if (*overlaps_a == chrec_dont_know
|
||
|| *overlaps_b == chrec_dont_know)
|
||
dependence_stats.num_miv_unimplemented++;
|
||
else if (*overlaps_a == chrec_known
|
||
|| *overlaps_b == chrec_known)
|
||
dependence_stats.num_miv_independent++;
|
||
else
|
||
dependence_stats.num_miv_dependent++;
|
||
}
|
||
|
||
else
|
||
{
|
||
/* When the analysis is too difficult, answer "don't know". */
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "analyze_miv_subscript test failed: unimplemented.\n");
|
||
|
||
*overlaps_a = chrec_dont_know;
|
||
*overlaps_b = chrec_dont_know;
|
||
*last_conflicts = chrec_dont_know;
|
||
dependence_stats.num_miv_unimplemented++;
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
/* Determines the iterations for which CHREC_A is equal to CHREC_B.
|
||
OVERLAP_ITERATIONS_A and OVERLAP_ITERATIONS_B are initialized with
|
||
two functions that describe the iterations that contain conflicting
|
||
elements.
|
||
|
||
Remark: For an integer k >= 0, the following equality is true:
|
||
|
||
CHREC_A (OVERLAP_ITERATIONS_A (k)) == CHREC_B (OVERLAP_ITERATIONS_B (k)).
|
||
*/
|
||
|
||
static void
|
||
analyze_overlapping_iterations (tree chrec_a,
|
||
tree chrec_b,
|
||
tree *overlap_iterations_a,
|
||
tree *overlap_iterations_b,
|
||
tree *last_conflicts)
|
||
{
|
||
dependence_stats.num_subscript_tests++;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "(analyze_overlapping_iterations \n");
|
||
fprintf (dump_file, " (chrec_a = ");
|
||
print_generic_expr (dump_file, chrec_a, 0);
|
||
fprintf (dump_file, ")\n (chrec_b = ");
|
||
print_generic_expr (dump_file, chrec_b, 0);
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
if (chrec_a == NULL_TREE
|
||
|| chrec_b == NULL_TREE
|
||
|| chrec_contains_undetermined (chrec_a)
|
||
|| chrec_contains_undetermined (chrec_b))
|
||
{
|
||
dependence_stats.num_subscript_undetermined++;
|
||
|
||
*overlap_iterations_a = chrec_dont_know;
|
||
*overlap_iterations_b = chrec_dont_know;
|
||
}
|
||
|
||
/* If they are the same chrec, and are affine, they overlap
|
||
on every iteration. */
|
||
else if (eq_evolutions_p (chrec_a, chrec_b)
|
||
&& evolution_function_is_affine_multivariate_p (chrec_a))
|
||
{
|
||
dependence_stats.num_same_subscript_function++;
|
||
*overlap_iterations_a = integer_zero_node;
|
||
*overlap_iterations_b = integer_zero_node;
|
||
*last_conflicts = chrec_dont_know;
|
||
}
|
||
|
||
/* If they aren't the same, and aren't affine, we can't do anything
|
||
yet. */
|
||
else if ((chrec_contains_symbols (chrec_a)
|
||
|| chrec_contains_symbols (chrec_b))
|
||
&& (!evolution_function_is_affine_multivariate_p (chrec_a)
|
||
|| !evolution_function_is_affine_multivariate_p (chrec_b)))
|
||
{
|
||
dependence_stats.num_subscript_undetermined++;
|
||
*overlap_iterations_a = chrec_dont_know;
|
||
*overlap_iterations_b = chrec_dont_know;
|
||
}
|
||
|
||
else if (ziv_subscript_p (chrec_a, chrec_b))
|
||
analyze_ziv_subscript (chrec_a, chrec_b,
|
||
overlap_iterations_a, overlap_iterations_b,
|
||
last_conflicts);
|
||
|
||
else if (siv_subscript_p (chrec_a, chrec_b))
|
||
analyze_siv_subscript (chrec_a, chrec_b,
|
||
overlap_iterations_a, overlap_iterations_b,
|
||
last_conflicts);
|
||
|
||
else
|
||
analyze_miv_subscript (chrec_a, chrec_b,
|
||
overlap_iterations_a, overlap_iterations_b,
|
||
last_conflicts);
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, " (overlap_iterations_a = ");
|
||
print_generic_expr (dump_file, *overlap_iterations_a, 0);
|
||
fprintf (dump_file, ")\n (overlap_iterations_b = ");
|
||
print_generic_expr (dump_file, *overlap_iterations_b, 0);
|
||
fprintf (dump_file, ")\n");
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
}
|
||
|
||
/* Helper function for uniquely inserting distance vectors. */
|
||
|
||
static void
|
||
save_dist_v (struct data_dependence_relation *ddr, lambda_vector dist_v)
|
||
{
|
||
unsigned i;
|
||
lambda_vector v;
|
||
|
||
for (i = 0; VEC_iterate (lambda_vector, DDR_DIST_VECTS (ddr), i, v); i++)
|
||
if (lambda_vector_equal (v, dist_v, DDR_NB_LOOPS (ddr)))
|
||
return;
|
||
|
||
VEC_safe_push (lambda_vector, heap, DDR_DIST_VECTS (ddr), dist_v);
|
||
}
|
||
|
||
/* Helper function for uniquely inserting direction vectors. */
|
||
|
||
static void
|
||
save_dir_v (struct data_dependence_relation *ddr, lambda_vector dir_v)
|
||
{
|
||
unsigned i;
|
||
lambda_vector v;
|
||
|
||
for (i = 0; VEC_iterate (lambda_vector, DDR_DIR_VECTS (ddr), i, v); i++)
|
||
if (lambda_vector_equal (v, dir_v, DDR_NB_LOOPS (ddr)))
|
||
return;
|
||
|
||
VEC_safe_push (lambda_vector, heap, DDR_DIR_VECTS (ddr), dir_v);
|
||
}
|
||
|
||
/* Add a distance of 1 on all the loops outer than INDEX. If we
|
||
haven't yet determined a distance for this outer loop, push a new
|
||
distance vector composed of the previous distance, and a distance
|
||
of 1 for this outer loop. Example:
|
||
|
||
| loop_1
|
||
| loop_2
|
||
| A[10]
|
||
| endloop_2
|
||
| endloop_1
|
||
|
||
Saved vectors are of the form (dist_in_1, dist_in_2). First, we
|
||
save (0, 1), then we have to save (1, 0). */
|
||
|
||
static void
|
||
add_outer_distances (struct data_dependence_relation *ddr,
|
||
lambda_vector dist_v, int index)
|
||
{
|
||
/* For each outer loop where init_v is not set, the accesses are
|
||
in dependence of distance 1 in the loop. */
|
||
while (--index >= 0)
|
||
{
|
||
lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
lambda_vector_copy (dist_v, save_v, DDR_NB_LOOPS (ddr));
|
||
save_v[index] = 1;
|
||
save_dist_v (ddr, save_v);
|
||
}
|
||
}
|
||
|
||
/* Return false when fail to represent the data dependence as a
|
||
distance vector. INIT_B is set to true when a component has been
|
||
added to the distance vector DIST_V. INDEX_CARRY is then set to
|
||
the index in DIST_V that carries the dependence. */
|
||
|
||
static bool
|
||
build_classic_dist_vector_1 (struct data_dependence_relation *ddr,
|
||
struct data_reference *ddr_a,
|
||
struct data_reference *ddr_b,
|
||
lambda_vector dist_v, bool *init_b,
|
||
int *index_carry)
|
||
{
|
||
unsigned i;
|
||
lambda_vector init_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
|
||
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
|
||
{
|
||
tree access_fn_a, access_fn_b;
|
||
struct subscript *subscript = DDR_SUBSCRIPT (ddr, i);
|
||
|
||
if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
|
||
{
|
||
non_affine_dependence_relation (ddr);
|
||
return false;
|
||
}
|
||
|
||
access_fn_a = DR_ACCESS_FN (ddr_a, i);
|
||
access_fn_b = DR_ACCESS_FN (ddr_b, i);
|
||
|
||
if (TREE_CODE (access_fn_a) == POLYNOMIAL_CHREC
|
||
&& TREE_CODE (access_fn_b) == POLYNOMIAL_CHREC)
|
||
{
|
||
int dist, index;
|
||
int index_a = index_in_loop_nest (CHREC_VARIABLE (access_fn_a),
|
||
DDR_LOOP_NEST (ddr));
|
||
int index_b = index_in_loop_nest (CHREC_VARIABLE (access_fn_b),
|
||
DDR_LOOP_NEST (ddr));
|
||
|
||
/* The dependence is carried by the outermost loop. Example:
|
||
| loop_1
|
||
| A[{4, +, 1}_1]
|
||
| loop_2
|
||
| A[{5, +, 1}_2]
|
||
| endloop_2
|
||
| endloop_1
|
||
In this case, the dependence is carried by loop_1. */
|
||
index = index_a < index_b ? index_a : index_b;
|
||
*index_carry = MIN (index, *index_carry);
|
||
|
||
if (chrec_contains_undetermined (SUB_DISTANCE (subscript)))
|
||
{
|
||
non_affine_dependence_relation (ddr);
|
||
return false;
|
||
}
|
||
|
||
dist = int_cst_value (SUB_DISTANCE (subscript));
|
||
|
||
/* This is the subscript coupling test. If we have already
|
||
recorded a distance for this loop (a distance coming from
|
||
another subscript), it should be the same. For example,
|
||
in the following code, there is no dependence:
|
||
|
||
| loop i = 0, N, 1
|
||
| T[i+1][i] = ...
|
||
| ... = T[i][i]
|
||
| endloop
|
||
*/
|
||
if (init_v[index] != 0 && dist_v[index] != dist)
|
||
{
|
||
finalize_ddr_dependent (ddr, chrec_known);
|
||
return false;
|
||
}
|
||
|
||
dist_v[index] = dist;
|
||
init_v[index] = 1;
|
||
*init_b = true;
|
||
}
|
||
else
|
||
{
|
||
/* This can be for example an affine vs. constant dependence
|
||
(T[i] vs. T[3]) that is not an affine dependence and is
|
||
not representable as a distance vector. */
|
||
non_affine_dependence_relation (ddr);
|
||
return false;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Return true when the DDR contains two data references that have the
|
||
same access functions. */
|
||
|
||
static bool
|
||
same_access_functions (struct data_dependence_relation *ddr)
|
||
{
|
||
unsigned i;
|
||
|
||
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
|
||
if (!eq_evolutions_p (DR_ACCESS_FN (DDR_A (ddr), i),
|
||
DR_ACCESS_FN (DDR_B (ddr), i)))
|
||
return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Helper function for the case where DDR_A and DDR_B are the same
|
||
multivariate access function. */
|
||
|
||
static void
|
||
add_multivariate_self_dist (struct data_dependence_relation *ddr, tree c_2)
|
||
{
|
||
int x_1, x_2;
|
||
tree c_1 = CHREC_LEFT (c_2);
|
||
tree c_0 = CHREC_LEFT (c_1);
|
||
lambda_vector dist_v;
|
||
|
||
/* Polynomials with more than 2 variables are not handled yet. */
|
||
if (TREE_CODE (c_0) != INTEGER_CST)
|
||
{
|
||
DDR_ARE_DEPENDENT (ddr) = chrec_dont_know;
|
||
return;
|
||
}
|
||
|
||
x_2 = index_in_loop_nest (CHREC_VARIABLE (c_2), DDR_LOOP_NEST (ddr));
|
||
x_1 = index_in_loop_nest (CHREC_VARIABLE (c_1), DDR_LOOP_NEST (ddr));
|
||
|
||
/* For "{{0, +, 2}_1, +, 3}_2" the distance vector is (3, -2). */
|
||
dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
dist_v[x_1] = int_cst_value (CHREC_RIGHT (c_2));
|
||
dist_v[x_2] = -int_cst_value (CHREC_RIGHT (c_1));
|
||
save_dist_v (ddr, dist_v);
|
||
|
||
add_outer_distances (ddr, dist_v, x_1);
|
||
}
|
||
|
||
/* Helper function for the case where DDR_A and DDR_B are the same
|
||
access functions. */
|
||
|
||
static void
|
||
add_other_self_distances (struct data_dependence_relation *ddr)
|
||
{
|
||
lambda_vector dist_v;
|
||
unsigned i;
|
||
int index_carry = DDR_NB_LOOPS (ddr);
|
||
|
||
for (i = 0; i < DDR_NUM_SUBSCRIPTS (ddr); i++)
|
||
{
|
||
tree access_fun = DR_ACCESS_FN (DDR_A (ddr), i);
|
||
|
||
if (TREE_CODE (access_fun) == POLYNOMIAL_CHREC)
|
||
{
|
||
if (!evolution_function_is_univariate_p (access_fun))
|
||
{
|
||
if (DDR_NUM_SUBSCRIPTS (ddr) != 1)
|
||
{
|
||
DDR_ARE_DEPENDENT (ddr) = chrec_dont_know;
|
||
return;
|
||
}
|
||
|
||
add_multivariate_self_dist (ddr, DR_ACCESS_FN (DDR_A (ddr), 0));
|
||
return;
|
||
}
|
||
|
||
index_carry = MIN (index_carry,
|
||
index_in_loop_nest (CHREC_VARIABLE (access_fun),
|
||
DDR_LOOP_NEST (ddr)));
|
||
}
|
||
}
|
||
|
||
dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
add_outer_distances (ddr, dist_v, index_carry);
|
||
}
|
||
|
||
/* Compute the classic per loop distance vector. DDR is the data
|
||
dependence relation to build a vector from. Return false when fail
|
||
to represent the data dependence as a distance vector. */
|
||
|
||
static bool
|
||
build_classic_dist_vector (struct data_dependence_relation *ddr)
|
||
{
|
||
bool init_b = false;
|
||
int index_carry = DDR_NB_LOOPS (ddr);
|
||
lambda_vector dist_v;
|
||
|
||
if (DDR_ARE_DEPENDENT (ddr) != NULL_TREE)
|
||
return true;
|
||
|
||
if (same_access_functions (ddr))
|
||
{
|
||
/* Save the 0 vector. */
|
||
dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
save_dist_v (ddr, dist_v);
|
||
|
||
if (DDR_NB_LOOPS (ddr) > 1)
|
||
add_other_self_distances (ddr);
|
||
|
||
return true;
|
||
}
|
||
|
||
dist_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
if (!build_classic_dist_vector_1 (ddr, DDR_A (ddr), DDR_B (ddr),
|
||
dist_v, &init_b, &index_carry))
|
||
return false;
|
||
|
||
/* Save the distance vector if we initialized one. */
|
||
if (init_b)
|
||
{
|
||
/* Verify a basic constraint: classic distance vectors should
|
||
always be lexicographically positive.
|
||
|
||
Data references are collected in the order of execution of
|
||
the program, thus for the following loop
|
||
|
||
| for (i = 1; i < 100; i++)
|
||
| for (j = 1; j < 100; j++)
|
||
| {
|
||
| t = T[j+1][i-1]; // A
|
||
| T[j][i] = t + 2; // B
|
||
| }
|
||
|
||
references are collected following the direction of the wind:
|
||
A then B. The data dependence tests are performed also
|
||
following this order, such that we're looking at the distance
|
||
separating the elements accessed by A from the elements later
|
||
accessed by B. But in this example, the distance returned by
|
||
test_dep (A, B) is lexicographically negative (-1, 1), that
|
||
means that the access A occurs later than B with respect to
|
||
the outer loop, ie. we're actually looking upwind. In this
|
||
case we solve test_dep (B, A) looking downwind to the
|
||
lexicographically positive solution, that returns the
|
||
distance vector (1, -1). */
|
||
if (!lambda_vector_lexico_pos (dist_v, DDR_NB_LOOPS (ddr)))
|
||
{
|
||
lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
subscript_dependence_tester_1 (ddr, DDR_B (ddr), DDR_A (ddr));
|
||
compute_subscript_distance (ddr);
|
||
build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr),
|
||
save_v, &init_b, &index_carry);
|
||
save_dist_v (ddr, save_v);
|
||
|
||
/* In this case there is a dependence forward for all the
|
||
outer loops:
|
||
|
||
| for (k = 1; k < 100; k++)
|
||
| for (i = 1; i < 100; i++)
|
||
| for (j = 1; j < 100; j++)
|
||
| {
|
||
| t = T[j+1][i-1]; // A
|
||
| T[j][i] = t + 2; // B
|
||
| }
|
||
|
||
the vectors are:
|
||
(0, 1, -1)
|
||
(1, 1, -1)
|
||
(1, -1, 1)
|
||
*/
|
||
if (DDR_NB_LOOPS (ddr) > 1)
|
||
{
|
||
add_outer_distances (ddr, save_v, index_carry);
|
||
add_outer_distances (ddr, dist_v, index_carry);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
lambda_vector save_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
lambda_vector_copy (dist_v, save_v, DDR_NB_LOOPS (ddr));
|
||
save_dist_v (ddr, save_v);
|
||
|
||
if (DDR_NB_LOOPS (ddr) > 1)
|
||
{
|
||
lambda_vector opposite_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
|
||
subscript_dependence_tester_1 (ddr, DDR_B (ddr), DDR_A (ddr));
|
||
compute_subscript_distance (ddr);
|
||
build_classic_dist_vector_1 (ddr, DDR_B (ddr), DDR_A (ddr),
|
||
opposite_v, &init_b, &index_carry);
|
||
|
||
add_outer_distances (ddr, dist_v, index_carry);
|
||
add_outer_distances (ddr, opposite_v, index_carry);
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* There is a distance of 1 on all the outer loops: Example:
|
||
there is a dependence of distance 1 on loop_1 for the array A.
|
||
|
||
| loop_1
|
||
| A[5] = ...
|
||
| endloop
|
||
*/
|
||
add_outer_distances (ddr, dist_v,
|
||
lambda_vector_first_nz (dist_v,
|
||
DDR_NB_LOOPS (ddr), 0));
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
unsigned i;
|
||
|
||
fprintf (dump_file, "(build_classic_dist_vector\n");
|
||
for (i = 0; i < DDR_NUM_DIST_VECTS (ddr); i++)
|
||
{
|
||
fprintf (dump_file, " dist_vector = (");
|
||
print_lambda_vector (dump_file, DDR_DIST_VECT (ddr, i),
|
||
DDR_NB_LOOPS (ddr));
|
||
fprintf (dump_file, " )\n");
|
||
}
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Return the direction for a given distance.
|
||
FIXME: Computing dir this way is suboptimal, since dir can catch
|
||
cases that dist is unable to represent. */
|
||
|
||
static inline enum data_dependence_direction
|
||
dir_from_dist (int dist)
|
||
{
|
||
if (dist > 0)
|
||
return dir_positive;
|
||
else if (dist < 0)
|
||
return dir_negative;
|
||
else
|
||
return dir_equal;
|
||
}
|
||
|
||
/* Compute the classic per loop direction vector. DDR is the data
|
||
dependence relation to build a vector from. */
|
||
|
||
static void
|
||
build_classic_dir_vector (struct data_dependence_relation *ddr)
|
||
{
|
||
unsigned i, j;
|
||
lambda_vector dist_v;
|
||
|
||
for (i = 0; VEC_iterate (lambda_vector, DDR_DIST_VECTS (ddr), i, dist_v); i++)
|
||
{
|
||
lambda_vector dir_v = lambda_vector_new (DDR_NB_LOOPS (ddr));
|
||
|
||
for (j = 0; j < DDR_NB_LOOPS (ddr); j++)
|
||
dir_v[j] = dir_from_dist (dist_v[j]);
|
||
|
||
save_dir_v (ddr, dir_v);
|
||
}
|
||
}
|
||
|
||
/* Helper function. Returns true when there is a dependence between
|
||
data references DRA and DRB. */
|
||
|
||
static bool
|
||
subscript_dependence_tester_1 (struct data_dependence_relation *ddr,
|
||
struct data_reference *dra,
|
||
struct data_reference *drb)
|
||
{
|
||
unsigned int i;
|
||
tree last_conflicts;
|
||
struct subscript *subscript;
|
||
|
||
for (i = 0; VEC_iterate (subscript_p, DDR_SUBSCRIPTS (ddr), i, subscript);
|
||
i++)
|
||
{
|
||
tree overlaps_a, overlaps_b;
|
||
|
||
analyze_overlapping_iterations (DR_ACCESS_FN (dra, i),
|
||
DR_ACCESS_FN (drb, i),
|
||
&overlaps_a, &overlaps_b,
|
||
&last_conflicts);
|
||
|
||
if (chrec_contains_undetermined (overlaps_a)
|
||
|| chrec_contains_undetermined (overlaps_b))
|
||
{
|
||
finalize_ddr_dependent (ddr, chrec_dont_know);
|
||
dependence_stats.num_dependence_undetermined++;
|
||
return false;
|
||
}
|
||
|
||
else if (overlaps_a == chrec_known
|
||
|| overlaps_b == chrec_known)
|
||
{
|
||
finalize_ddr_dependent (ddr, chrec_known);
|
||
dependence_stats.num_dependence_independent++;
|
||
return false;
|
||
}
|
||
|
||
else
|
||
{
|
||
SUB_CONFLICTS_IN_A (subscript) = overlaps_a;
|
||
SUB_CONFLICTS_IN_B (subscript) = overlaps_b;
|
||
SUB_LAST_CONFLICT (subscript) = last_conflicts;
|
||
}
|
||
}
|
||
|
||
return true;
|
||
}
|
||
|
||
/* Computes the conflicting iterations, and initialize DDR. */
|
||
|
||
static void
|
||
subscript_dependence_tester (struct data_dependence_relation *ddr)
|
||
{
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, "(subscript_dependence_tester \n");
|
||
|
||
if (subscript_dependence_tester_1 (ddr, DDR_A (ddr), DDR_B (ddr)))
|
||
dependence_stats.num_dependence_dependent++;
|
||
|
||
compute_subscript_distance (ddr);
|
||
if (build_classic_dist_vector (ddr))
|
||
build_classic_dir_vector (ddr);
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
/* Returns true when all the access functions of A are affine or
|
||
constant. */
|
||
|
||
static bool
|
||
access_functions_are_affine_or_constant_p (struct data_reference *a)
|
||
{
|
||
unsigned int i;
|
||
VEC(tree,heap) **fns = DR_ACCESS_FNS_ADDR (a);
|
||
tree t;
|
||
|
||
for (i = 0; VEC_iterate (tree, *fns, i, t); i++)
|
||
if (!evolution_function_is_constant_p (t)
|
||
&& !evolution_function_is_affine_multivariate_p (t))
|
||
return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
/* This computes the affine dependence relation between A and B.
|
||
CHREC_KNOWN is used for representing the independence between two
|
||
accesses, while CHREC_DONT_KNOW is used for representing the unknown
|
||
relation.
|
||
|
||
Note that it is possible to stop the computation of the dependence
|
||
relation the first time we detect a CHREC_KNOWN element for a given
|
||
subscript. */
|
||
|
||
static void
|
||
compute_affine_dependence (struct data_dependence_relation *ddr)
|
||
{
|
||
struct data_reference *dra = DDR_A (ddr);
|
||
struct data_reference *drb = DDR_B (ddr);
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "(compute_affine_dependence\n");
|
||
fprintf (dump_file, " (stmt_a = \n");
|
||
print_generic_expr (dump_file, DR_STMT (dra), 0);
|
||
fprintf (dump_file, ")\n (stmt_b = \n");
|
||
print_generic_expr (dump_file, DR_STMT (drb), 0);
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
/* Analyze only when the dependence relation is not yet known. */
|
||
if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE)
|
||
{
|
||
dependence_stats.num_dependence_tests++;
|
||
|
||
if (access_functions_are_affine_or_constant_p (dra)
|
||
&& access_functions_are_affine_or_constant_p (drb))
|
||
subscript_dependence_tester (ddr);
|
||
|
||
/* As a last case, if the dependence cannot be determined, or if
|
||
the dependence is considered too difficult to determine, answer
|
||
"don't know". */
|
||
else
|
||
{
|
||
dependence_stats.num_dependence_undetermined++;
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
{
|
||
fprintf (dump_file, "Data ref a:\n");
|
||
dump_data_reference (dump_file, dra);
|
||
fprintf (dump_file, "Data ref b:\n");
|
||
dump_data_reference (dump_file, drb);
|
||
fprintf (dump_file, "affine dependence test not usable: access function not affine or constant.\n");
|
||
}
|
||
finalize_ddr_dependent (ddr, chrec_dont_know);
|
||
}
|
||
}
|
||
|
||
if (dump_file && (dump_flags & TDF_DETAILS))
|
||
fprintf (dump_file, ")\n");
|
||
}
|
||
|
||
/* This computes the dependence relation for the same data
|
||
reference into DDR. */
|
||
|
||
static void
|
||
compute_self_dependence (struct data_dependence_relation *ddr)
|
||
{
|
||
unsigned int i;
|
||
struct subscript *subscript;
|
||
|
||
for (i = 0; VEC_iterate (subscript_p, DDR_SUBSCRIPTS (ddr), i, subscript);
|
||
i++)
|
||
{
|
||
/* The accessed index overlaps for each iteration. */
|
||
SUB_CONFLICTS_IN_A (subscript) = integer_zero_node;
|
||
SUB_CONFLICTS_IN_B (subscript) = integer_zero_node;
|
||
SUB_LAST_CONFLICT (subscript) = chrec_dont_know;
|
||
}
|
||
|
||
/* The distance vector is the zero vector. */
|
||
save_dist_v (ddr, lambda_vector_new (DDR_NB_LOOPS (ddr)));
|
||
save_dir_v (ddr, lambda_vector_new (DDR_NB_LOOPS (ddr)));
|
||
}
|
||
|
||
/* Compute in DEPENDENCE_RELATIONS the data dependence graph for all
|
||
the data references in DATAREFS, in the LOOP_NEST. When
|
||
COMPUTE_SELF_AND_RR is FALSE, don't compute read-read and self
|
||
relations. */
|
||
|
||
static void
|
||
compute_all_dependences (VEC (data_reference_p, heap) *datarefs,
|
||
VEC (ddr_p, heap) **dependence_relations,
|
||
VEC (loop_p, heap) *loop_nest,
|
||
bool compute_self_and_rr)
|
||
{
|
||
struct data_dependence_relation *ddr;
|
||
struct data_reference *a, *b;
|
||
unsigned int i, j;
|
||
|
||
for (i = 0; VEC_iterate (data_reference_p, datarefs, i, a); i++)
|
||
for (j = i + 1; VEC_iterate (data_reference_p, datarefs, j, b); j++)
|
||
if (!DR_IS_READ (a) || !DR_IS_READ (b) || compute_self_and_rr)
|
||
{
|
||
ddr = initialize_data_dependence_relation (a, b, loop_nest);
|
||
VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
|
||
compute_affine_dependence (ddr);
|
||
}
|
||
|
||
if (compute_self_and_rr)
|
||
for (i = 0; VEC_iterate (data_reference_p, datarefs, i, a); i++)
|
||
{
|
||
ddr = initialize_data_dependence_relation (a, a, loop_nest);
|
||
VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
|
||
compute_self_dependence (ddr);
|
||
}
|
||
}
|
||
|
||
/* Search the data references in LOOP, and record the information into
|
||
DATAREFS. Returns chrec_dont_know when failing to analyze a
|
||
difficult case, returns NULL_TREE otherwise.
|
||
|
||
TODO: This function should be made smarter so that it can handle address
|
||
arithmetic as if they were array accesses, etc. */
|
||
|
||
tree
|
||
find_data_references_in_loop (struct loop *loop,
|
||
VEC (data_reference_p, heap) **datarefs)
|
||
{
|
||
basic_block bb, *bbs;
|
||
unsigned int i;
|
||
block_stmt_iterator bsi;
|
||
struct data_reference *dr;
|
||
|
||
bbs = get_loop_body (loop);
|
||
|
||
for (i = 0; i < loop->num_nodes; i++)
|
||
{
|
||
bb = bbs[i];
|
||
|
||
for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
|
||
{
|
||
tree stmt = bsi_stmt (bsi);
|
||
|
||
/* ASM_EXPR and CALL_EXPR may embed arbitrary side effects.
|
||
Calls have side-effects, except those to const or pure
|
||
functions. */
|
||
if ((TREE_CODE (stmt) == CALL_EXPR
|
||
&& !(call_expr_flags (stmt) & (ECF_CONST | ECF_PURE)))
|
||
|| (TREE_CODE (stmt) == ASM_EXPR
|
||
&& ASM_VOLATILE_P (stmt)))
|
||
goto insert_dont_know_node;
|
||
|
||
if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
|
||
continue;
|
||
|
||
switch (TREE_CODE (stmt))
|
||
{
|
||
case MODIFY_EXPR:
|
||
{
|
||
bool one_inserted = false;
|
||
tree opnd0 = TREE_OPERAND (stmt, 0);
|
||
tree opnd1 = TREE_OPERAND (stmt, 1);
|
||
|
||
if (TREE_CODE (opnd0) == ARRAY_REF
|
||
|| TREE_CODE (opnd0) == INDIRECT_REF
|
||
|| TREE_CODE (opnd0) == COMPONENT_REF)
|
||
{
|
||
dr = create_data_ref (opnd0, stmt, false);
|
||
if (dr)
|
||
{
|
||
VEC_safe_push (data_reference_p, heap, *datarefs, dr);
|
||
one_inserted = true;
|
||
}
|
||
}
|
||
|
||
if (TREE_CODE (opnd1) == ARRAY_REF
|
||
|| TREE_CODE (opnd1) == INDIRECT_REF
|
||
|| TREE_CODE (opnd1) == COMPONENT_REF)
|
||
{
|
||
dr = create_data_ref (opnd1, stmt, true);
|
||
if (dr)
|
||
{
|
||
VEC_safe_push (data_reference_p, heap, *datarefs, dr);
|
||
one_inserted = true;
|
||
}
|
||
}
|
||
|
||
if (!one_inserted)
|
||
goto insert_dont_know_node;
|
||
|
||
break;
|
||
}
|
||
|
||
case CALL_EXPR:
|
||
{
|
||
tree args;
|
||
bool one_inserted = false;
|
||
|
||
for (args = TREE_OPERAND (stmt, 1); args;
|
||
args = TREE_CHAIN (args))
|
||
if (TREE_CODE (TREE_VALUE (args)) == ARRAY_REF
|
||
|| TREE_CODE (TREE_VALUE (args)) == INDIRECT_REF
|
||
|| TREE_CODE (TREE_VALUE (args)) == COMPONENT_REF)
|
||
{
|
||
dr = create_data_ref (TREE_VALUE (args), stmt, true);
|
||
if (dr)
|
||
{
|
||
VEC_safe_push (data_reference_p, heap, *datarefs, dr);
|
||
one_inserted = true;
|
||
}
|
||
}
|
||
|
||
if (!one_inserted)
|
||
goto insert_dont_know_node;
|
||
|
||
break;
|
||
}
|
||
|
||
default:
|
||
{
|
||
struct data_reference *res;
|
||
|
||
insert_dont_know_node:;
|
||
res = XNEW (struct data_reference);
|
||
DR_STMT (res) = NULL_TREE;
|
||
DR_REF (res) = NULL_TREE;
|
||
DR_BASE_OBJECT (res) = NULL;
|
||
DR_TYPE (res) = ARRAY_REF_TYPE;
|
||
DR_SET_ACCESS_FNS (res, NULL);
|
||
DR_BASE_OBJECT (res) = NULL;
|
||
DR_IS_READ (res) = false;
|
||
DR_BASE_ADDRESS (res) = NULL_TREE;
|
||
DR_OFFSET (res) = NULL_TREE;
|
||
DR_INIT (res) = NULL_TREE;
|
||
DR_STEP (res) = NULL_TREE;
|
||
DR_OFFSET_MISALIGNMENT (res) = NULL_TREE;
|
||
DR_MEMTAG (res) = NULL_TREE;
|
||
DR_PTR_INFO (res) = NULL;
|
||
VEC_safe_push (data_reference_p, heap, *datarefs, res);
|
||
|
||
free (bbs);
|
||
return chrec_dont_know;
|
||
}
|
||
}
|
||
|
||
/* When there are no defs in the loop, the loop is parallel. */
|
||
if (!ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_DEFS))
|
||
loop->parallel_p = false;
|
||
}
|
||
}
|
||
|
||
free (bbs);
|
||
|
||
return NULL_TREE;
|
||
}
|
||
|
||
/* Recursive helper function. */
|
||
|
||
static bool
|
||
find_loop_nest_1 (struct loop *loop, VEC (loop_p, heap) **loop_nest)
|
||
{
|
||
/* Inner loops of the nest should not contain siblings. Example:
|
||
when there are two consecutive loops,
|
||
|
||
| loop_0
|
||
| loop_1
|
||
| A[{0, +, 1}_1]
|
||
| endloop_1
|
||
| loop_2
|
||
| A[{0, +, 1}_2]
|
||
| endloop_2
|
||
| endloop_0
|
||
|
||
the dependence relation cannot be captured by the distance
|
||
abstraction. */
|
||
if (loop->next)
|
||
return false;
|
||
|
||
VEC_safe_push (loop_p, heap, *loop_nest, loop);
|
||
if (loop->inner)
|
||
return find_loop_nest_1 (loop->inner, loop_nest);
|
||
return true;
|
||
}
|
||
|
||
/* Return false when the LOOP is not well nested. Otherwise return
|
||
true and insert in LOOP_NEST the loops of the nest. LOOP_NEST will
|
||
contain the loops from the outermost to the innermost, as they will
|
||
appear in the classic distance vector. */
|
||
|
||
static bool
|
||
find_loop_nest (struct loop *loop, VEC (loop_p, heap) **loop_nest)
|
||
{
|
||
VEC_safe_push (loop_p, heap, *loop_nest, loop);
|
||
if (loop->inner)
|
||
return find_loop_nest_1 (loop->inner, loop_nest);
|
||
return true;
|
||
}
|
||
|
||
/* Given a loop nest LOOP, the following vectors are returned:
|
||
DATAREFS is initialized to all the array elements contained in this loop,
|
||
DEPENDENCE_RELATIONS contains the relations between the data references.
|
||
Compute read-read and self relations if
|
||
COMPUTE_SELF_AND_READ_READ_DEPENDENCES is TRUE. */
|
||
|
||
void
|
||
compute_data_dependences_for_loop (struct loop *loop,
|
||
bool compute_self_and_read_read_dependences,
|
||
VEC (data_reference_p, heap) **datarefs,
|
||
VEC (ddr_p, heap) **dependence_relations)
|
||
{
|
||
struct loop *loop_nest = loop;
|
||
VEC (loop_p, heap) *vloops = VEC_alloc (loop_p, heap, 3);
|
||
|
||
memset (&dependence_stats, 0, sizeof (dependence_stats));
|
||
|
||
/* If the loop nest is not well formed, or one of the data references
|
||
is not computable, give up without spending time to compute other
|
||
dependences. */
|
||
if (!loop_nest
|
||
|| !find_loop_nest (loop_nest, &vloops)
|
||
|| find_data_references_in_loop (loop, datarefs) == chrec_dont_know)
|
||
{
|
||
struct data_dependence_relation *ddr;
|
||
|
||
/* Insert a single relation into dependence_relations:
|
||
chrec_dont_know. */
|
||
ddr = initialize_data_dependence_relation (NULL, NULL, vloops);
|
||
VEC_safe_push (ddr_p, heap, *dependence_relations, ddr);
|
||
}
|
||
else
|
||
compute_all_dependences (*datarefs, dependence_relations, vloops,
|
||
compute_self_and_read_read_dependences);
|
||
|
||
if (dump_file && (dump_flags & TDF_STATS))
|
||
{
|
||
fprintf (dump_file, "Dependence tester statistics:\n");
|
||
|
||
fprintf (dump_file, "Number of dependence tests: %d\n",
|
||
dependence_stats.num_dependence_tests);
|
||
fprintf (dump_file, "Number of dependence tests classified dependent: %d\n",
|
||
dependence_stats.num_dependence_dependent);
|
||
fprintf (dump_file, "Number of dependence tests classified independent: %d\n",
|
||
dependence_stats.num_dependence_independent);
|
||
fprintf (dump_file, "Number of undetermined dependence tests: %d\n",
|
||
dependence_stats.num_dependence_undetermined);
|
||
|
||
fprintf (dump_file, "Number of subscript tests: %d\n",
|
||
dependence_stats.num_subscript_tests);
|
||
fprintf (dump_file, "Number of undetermined subscript tests: %d\n",
|
||
dependence_stats.num_subscript_undetermined);
|
||
fprintf (dump_file, "Number of same subscript function: %d\n",
|
||
dependence_stats.num_same_subscript_function);
|
||
|
||
fprintf (dump_file, "Number of ziv tests: %d\n",
|
||
dependence_stats.num_ziv);
|
||
fprintf (dump_file, "Number of ziv tests returning dependent: %d\n",
|
||
dependence_stats.num_ziv_dependent);
|
||
fprintf (dump_file, "Number of ziv tests returning independent: %d\n",
|
||
dependence_stats.num_ziv_independent);
|
||
fprintf (dump_file, "Number of ziv tests unimplemented: %d\n",
|
||
dependence_stats.num_ziv_unimplemented);
|
||
|
||
fprintf (dump_file, "Number of siv tests: %d\n",
|
||
dependence_stats.num_siv);
|
||
fprintf (dump_file, "Number of siv tests returning dependent: %d\n",
|
||
dependence_stats.num_siv_dependent);
|
||
fprintf (dump_file, "Number of siv tests returning independent: %d\n",
|
||
dependence_stats.num_siv_independent);
|
||
fprintf (dump_file, "Number of siv tests unimplemented: %d\n",
|
||
dependence_stats.num_siv_unimplemented);
|
||
|
||
fprintf (dump_file, "Number of miv tests: %d\n",
|
||
dependence_stats.num_miv);
|
||
fprintf (dump_file, "Number of miv tests returning dependent: %d\n",
|
||
dependence_stats.num_miv_dependent);
|
||
fprintf (dump_file, "Number of miv tests returning independent: %d\n",
|
||
dependence_stats.num_miv_independent);
|
||
fprintf (dump_file, "Number of miv tests unimplemented: %d\n",
|
||
dependence_stats.num_miv_unimplemented);
|
||
}
|
||
}
|
||
|
||
/* Entry point (for testing only). Analyze all the data references
|
||
and the dependence relations.
|
||
|
||
The data references are computed first.
|
||
|
||
A relation on these nodes is represented by a complete graph. Some
|
||
of the relations could be of no interest, thus the relations can be
|
||
computed on demand.
|
||
|
||
In the following function we compute all the relations. This is
|
||
just a first implementation that is here for:
|
||
- for showing how to ask for the dependence relations,
|
||
- for the debugging the whole dependence graph,
|
||
- for the dejagnu testcases and maintenance.
|
||
|
||
It is possible to ask only for a part of the graph, avoiding to
|
||
compute the whole dependence graph. The computed dependences are
|
||
stored in a knowledge base (KB) such that later queries don't
|
||
recompute the same information. The implementation of this KB is
|
||
transparent to the optimizer, and thus the KB can be changed with a
|
||
more efficient implementation, or the KB could be disabled. */
|
||
#if 0
|
||
static void
|
||
analyze_all_data_dependences (struct loops *loops)
|
||
{
|
||
unsigned int i;
|
||
int nb_data_refs = 10;
|
||
VEC (data_reference_p, heap) *datarefs =
|
||
VEC_alloc (data_reference_p, heap, nb_data_refs);
|
||
VEC (ddr_p, heap) *dependence_relations =
|
||
VEC_alloc (ddr_p, heap, nb_data_refs * nb_data_refs);
|
||
|
||
/* Compute DDs on the whole function. */
|
||
compute_data_dependences_for_loop (loops->parray[0], false,
|
||
&datarefs, &dependence_relations);
|
||
|
||
if (dump_file)
|
||
{
|
||
dump_data_dependence_relations (dump_file, dependence_relations);
|
||
fprintf (dump_file, "\n\n");
|
||
|
||
if (dump_flags & TDF_DETAILS)
|
||
dump_dist_dir_vectors (dump_file, dependence_relations);
|
||
|
||
if (dump_flags & TDF_STATS)
|
||
{
|
||
unsigned nb_top_relations = 0;
|
||
unsigned nb_bot_relations = 0;
|
||
unsigned nb_basename_differ = 0;
|
||
unsigned nb_chrec_relations = 0;
|
||
struct data_dependence_relation *ddr;
|
||
|
||
for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++)
|
||
{
|
||
if (chrec_contains_undetermined (DDR_ARE_DEPENDENT (ddr)))
|
||
nb_top_relations++;
|
||
|
||
else if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
|
||
{
|
||
struct data_reference *a = DDR_A (ddr);
|
||
struct data_reference *b = DDR_B (ddr);
|
||
bool differ_p;
|
||
|
||
if ((DR_BASE_OBJECT (a) && DR_BASE_OBJECT (b)
|
||
&& DR_NUM_DIMENSIONS (a) != DR_NUM_DIMENSIONS (b))
|
||
|| (base_object_differ_p (a, b, &differ_p)
|
||
&& differ_p))
|
||
nb_basename_differ++;
|
||
else
|
||
nb_bot_relations++;
|
||
}
|
||
|
||
else
|
||
nb_chrec_relations++;
|
||
}
|
||
|
||
gather_stats_on_scev_database ();
|
||
}
|
||
}
|
||
|
||
free_dependence_relations (dependence_relations);
|
||
free_data_refs (datarefs);
|
||
}
|
||
#endif
|
||
|
||
/* Free the memory used by a data dependence relation DDR. */
|
||
|
||
void
|
||
free_dependence_relation (struct data_dependence_relation *ddr)
|
||
{
|
||
if (ddr == NULL)
|
||
return;
|
||
|
||
if (DDR_ARE_DEPENDENT (ddr) == NULL_TREE && DDR_SUBSCRIPTS (ddr))
|
||
VEC_free (subscript_p, heap, DDR_SUBSCRIPTS (ddr));
|
||
|
||
free (ddr);
|
||
}
|
||
|
||
/* Free the memory used by the data dependence relations from
|
||
DEPENDENCE_RELATIONS. */
|
||
|
||
void
|
||
free_dependence_relations (VEC (ddr_p, heap) *dependence_relations)
|
||
{
|
||
unsigned int i;
|
||
struct data_dependence_relation *ddr;
|
||
VEC (loop_p, heap) *loop_nest = NULL;
|
||
|
||
for (i = 0; VEC_iterate (ddr_p, dependence_relations, i, ddr); i++)
|
||
{
|
||
if (ddr == NULL)
|
||
continue;
|
||
if (loop_nest == NULL)
|
||
loop_nest = DDR_LOOP_NEST (ddr);
|
||
else
|
||
gcc_assert (DDR_LOOP_NEST (ddr) == NULL
|
||
|| DDR_LOOP_NEST (ddr) == loop_nest);
|
||
free_dependence_relation (ddr);
|
||
}
|
||
|
||
if (loop_nest)
|
||
VEC_free (loop_p, heap, loop_nest);
|
||
VEC_free (ddr_p, heap, dependence_relations);
|
||
}
|
||
|
||
/* Free the memory used by the data references from DATAREFS. */
|
||
|
||
void
|
||
free_data_refs (VEC (data_reference_p, heap) *datarefs)
|
||
{
|
||
unsigned int i;
|
||
struct data_reference *dr;
|
||
|
||
for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
|
||
free_data_ref (dr);
|
||
VEC_free (data_reference_p, heap, datarefs);
|
||
}
|
||
|