3568 lines
109 KiB
C
3568 lines
109 KiB
C
/* Statement simplification on GIMPLE.
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Copyright (C) 2010, 2011 Free Software Foundation, Inc.
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Split out from tree-ssa-ccp.c.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any
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later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tree.h"
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#include "flags.h"
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#include "function.h"
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#include "tree-dump.h"
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#include "tree-flow.h"
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#include "tree-pass.h"
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#include "tree-ssa-propagate.h"
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#include "target.h"
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#include "gimple-fold.h"
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/* Return true when DECL can be referenced from current unit.
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We can get declarations that are not possible to reference for
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various reasons:
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1) When analyzing C++ virtual tables.
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C++ virtual tables do have known constructors even
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when they are keyed to other compilation unit.
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Those tables can contain pointers to methods and vars
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in other units. Those methods have both STATIC and EXTERNAL
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set.
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2) In WHOPR mode devirtualization might lead to reference
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to method that was partitioned elsehwere.
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In this case we have static VAR_DECL or FUNCTION_DECL
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that has no corresponding callgraph/varpool node
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declaring the body.
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3) COMDAT functions referred by external vtables that
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we devirtualize only during final copmilation stage.
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At this time we already decided that we will not output
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the function body and thus we can't reference the symbol
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directly. */
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static bool
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can_refer_decl_in_current_unit_p (tree decl)
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{
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struct varpool_node *vnode;
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struct cgraph_node *node;
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if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
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return true;
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/* External flag is set, so we deal with C++ reference
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to static object from other file. */
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if (DECL_EXTERNAL (decl) && TREE_STATIC (decl)
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&& TREE_CODE (decl) == VAR_DECL)
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{
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/* Just be sure it is not big in frontend setting
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flags incorrectly. Those variables should never
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be finalized. */
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gcc_checking_assert (!(vnode = varpool_get_node (decl))
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|| !vnode->finalized);
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return false;
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}
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/* When function is public, we always can introduce new reference.
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Exception are the COMDAT functions where introducing a direct
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reference imply need to include function body in the curren tunit. */
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if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl))
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return true;
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/* We are not at ltrans stage; so don't worry about WHOPR.
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Also when still gimplifying all referred comdat functions will be
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produced.
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??? as observed in PR20991 for already optimized out comdat virtual functions
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we may not neccesarily give up because the copy will be output elsewhere when
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corresponding vtable is output. */
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if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready))
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return true;
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/* If we already output the function body, we are safe. */
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if (TREE_ASM_WRITTEN (decl))
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return true;
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if (TREE_CODE (decl) == FUNCTION_DECL)
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{
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node = cgraph_get_node (decl);
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/* Check that we still have function body and that we didn't took
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the decision to eliminate offline copy of the function yet.
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The second is important when devirtualization happens during final
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compilation stage when making a new reference no longer makes callee
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to be compiled. */
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if (!node || !node->analyzed || node->global.inlined_to)
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return false;
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}
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else if (TREE_CODE (decl) == VAR_DECL)
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{
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vnode = varpool_get_node (decl);
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if (!vnode || !vnode->finalized)
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return false;
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}
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return true;
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}
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/* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into
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acceptable form for is_gimple_min_invariant. */
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tree
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canonicalize_constructor_val (tree cval)
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{
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STRIP_NOPS (cval);
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if (TREE_CODE (cval) == POINTER_PLUS_EXPR)
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{
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tree t = maybe_fold_offset_to_address (EXPR_LOCATION (cval),
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TREE_OPERAND (cval, 0),
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TREE_OPERAND (cval, 1),
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TREE_TYPE (cval));
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if (t)
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cval = t;
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}
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if (TREE_CODE (cval) == ADDR_EXPR)
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{
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tree base = get_base_address (TREE_OPERAND (cval, 0));
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if (base
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&& (TREE_CODE (base) == VAR_DECL
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|| TREE_CODE (base) == FUNCTION_DECL)
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&& !can_refer_decl_in_current_unit_p (base))
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return NULL_TREE;
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if (cfun && base && TREE_CODE (base) == VAR_DECL)
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add_referenced_var (base);
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/* Fixup types in global initializers. */
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if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0)))
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cval = build_fold_addr_expr (TREE_OPERAND (cval, 0));
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}
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return cval;
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}
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/* If SYM is a constant variable with known value, return the value.
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NULL_TREE is returned otherwise. */
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tree
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get_symbol_constant_value (tree sym)
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{
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if (const_value_known_p (sym))
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{
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tree val = DECL_INITIAL (sym);
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if (val)
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{
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val = canonicalize_constructor_val (val);
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if (val && is_gimple_min_invariant (val))
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return val;
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else
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return NULL_TREE;
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}
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/* Variables declared 'const' without an initializer
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have zero as the initializer if they may not be
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overridden at link or run time. */
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if (!val
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&& (INTEGRAL_TYPE_P (TREE_TYPE (sym))
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|| SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym))))
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return build_zero_cst (TREE_TYPE (sym));
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}
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return NULL_TREE;
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}
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/* Return true if we may propagate the address expression ADDR into the
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dereference DEREF and cancel them. */
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bool
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may_propagate_address_into_dereference (tree addr, tree deref)
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{
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gcc_assert (TREE_CODE (deref) == MEM_REF
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&& TREE_CODE (addr) == ADDR_EXPR);
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/* Don't propagate if ADDR's operand has incomplete type. */
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if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_OPERAND (addr, 0))))
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return false;
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/* If the address is invariant then we do not need to preserve restrict
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qualifications. But we do need to preserve volatile qualifiers until
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we can annotate the folded dereference itself properly. */
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if (is_gimple_min_invariant (addr)
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&& (!TREE_THIS_VOLATILE (deref)
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|| TYPE_VOLATILE (TREE_TYPE (addr))))
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return useless_type_conversion_p (TREE_TYPE (deref),
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TREE_TYPE (TREE_OPERAND (addr, 0)));
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/* Else both the address substitution and the folding must result in
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a valid useless type conversion sequence. */
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return (useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (deref, 0)),
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TREE_TYPE (addr))
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&& useless_type_conversion_p (TREE_TYPE (deref),
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TREE_TYPE (TREE_OPERAND (addr, 0))));
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}
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/* A subroutine of fold_stmt. Attempts to fold *(A+O) to A[X].
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BASE is an array type. OFFSET is a byte displacement.
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LOC is the location of the original expression. */
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static tree
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maybe_fold_offset_to_array_ref (location_t loc, tree base, tree offset)
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{
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tree min_idx, idx, idx_type, elt_offset = integer_zero_node;
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tree array_type, elt_type, elt_size;
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tree domain_type;
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/* If BASE is an ARRAY_REF, we can pick up another offset (this time
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measured in units of the size of elements type) from that ARRAY_REF).
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We can't do anything if either is variable.
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The case we handle here is *(&A[N]+O). */
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if (TREE_CODE (base) == ARRAY_REF)
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{
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tree low_bound = array_ref_low_bound (base);
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elt_offset = TREE_OPERAND (base, 1);
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if (TREE_CODE (low_bound) != INTEGER_CST
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|| TREE_CODE (elt_offset) != INTEGER_CST)
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return NULL_TREE;
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elt_offset = int_const_binop (MINUS_EXPR, elt_offset, low_bound);
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base = TREE_OPERAND (base, 0);
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}
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/* Ignore stupid user tricks of indexing non-array variables. */
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array_type = TREE_TYPE (base);
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if (TREE_CODE (array_type) != ARRAY_TYPE)
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return NULL_TREE;
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elt_type = TREE_TYPE (array_type);
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/* Use signed size type for intermediate computation on the index. */
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idx_type = ssizetype;
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/* If OFFSET and ELT_OFFSET are zero, we don't care about the size of the
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element type (so we can use the alignment if it's not constant).
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Otherwise, compute the offset as an index by using a division. If the
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division isn't exact, then don't do anything. */
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elt_size = TYPE_SIZE_UNIT (elt_type);
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if (!elt_size)
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return NULL;
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if (integer_zerop (offset))
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{
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if (TREE_CODE (elt_size) != INTEGER_CST)
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elt_size = size_int (TYPE_ALIGN (elt_type));
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idx = build_int_cst (idx_type, 0);
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}
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else
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{
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unsigned HOST_WIDE_INT lquo, lrem;
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HOST_WIDE_INT hquo, hrem;
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double_int soffset;
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/* The final array offset should be signed, so we need
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to sign-extend the (possibly pointer) offset here
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and use signed division. */
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soffset = double_int_sext (tree_to_double_int (offset),
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TYPE_PRECISION (TREE_TYPE (offset)));
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if (TREE_CODE (elt_size) != INTEGER_CST
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|| div_and_round_double (TRUNC_DIV_EXPR, 0,
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soffset.low, soffset.high,
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TREE_INT_CST_LOW (elt_size),
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TREE_INT_CST_HIGH (elt_size),
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&lquo, &hquo, &lrem, &hrem)
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|| lrem || hrem)
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return NULL_TREE;
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idx = build_int_cst_wide (idx_type, lquo, hquo);
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}
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/* Assume the low bound is zero. If there is a domain type, get the
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low bound, if any, convert the index into that type, and add the
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low bound. */
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min_idx = build_int_cst (idx_type, 0);
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domain_type = TYPE_DOMAIN (array_type);
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if (domain_type)
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{
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idx_type = domain_type;
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if (TYPE_MIN_VALUE (idx_type))
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min_idx = TYPE_MIN_VALUE (idx_type);
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else
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min_idx = fold_convert (idx_type, min_idx);
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if (TREE_CODE (min_idx) != INTEGER_CST)
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return NULL_TREE;
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elt_offset = fold_convert (idx_type, elt_offset);
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}
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if (!integer_zerop (min_idx))
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idx = int_const_binop (PLUS_EXPR, idx, min_idx);
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if (!integer_zerop (elt_offset))
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idx = int_const_binop (PLUS_EXPR, idx, elt_offset);
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/* Make sure to possibly truncate late after offsetting. */
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idx = fold_convert (idx_type, idx);
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/* We don't want to construct access past array bounds. For example
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char *(c[4]);
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c[3][2];
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should not be simplified into (*c)[14] or tree-vrp will
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give false warnings.
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This is only an issue for multi-dimensional arrays. */
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if (TREE_CODE (elt_type) == ARRAY_TYPE
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&& domain_type)
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{
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if (TYPE_MAX_VALUE (domain_type)
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&& TREE_CODE (TYPE_MAX_VALUE (domain_type)) == INTEGER_CST
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&& tree_int_cst_lt (TYPE_MAX_VALUE (domain_type), idx))
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return NULL_TREE;
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else if (TYPE_MIN_VALUE (domain_type)
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&& TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST
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&& tree_int_cst_lt (idx, TYPE_MIN_VALUE (domain_type)))
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return NULL_TREE;
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else if (compare_tree_int (idx, 0) < 0)
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return NULL_TREE;
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}
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{
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tree t = build4 (ARRAY_REF, elt_type, base, idx, NULL_TREE, NULL_TREE);
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SET_EXPR_LOCATION (t, loc);
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return t;
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}
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}
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/* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE[index].
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LOC is the location of original expression.
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Before attempting the conversion strip off existing ADDR_EXPRs. */
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tree
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maybe_fold_offset_to_reference (location_t loc, tree base, tree offset,
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tree orig_type)
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{
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tree ret;
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STRIP_NOPS (base);
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if (TREE_CODE (base) != ADDR_EXPR)
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return NULL_TREE;
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base = TREE_OPERAND (base, 0);
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if (types_compatible_p (orig_type, TREE_TYPE (base))
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&& integer_zerop (offset))
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return base;
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ret = maybe_fold_offset_to_array_ref (loc, base, offset);
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if (ret && types_compatible_p (orig_type, TREE_TYPE (ret)))
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return ret;
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return NULL_TREE;
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}
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/* Attempt to express (ORIG_TYPE)ADDR+OFFSET as (*ADDR)[index].
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LOC is the location of the original expression. */
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tree
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maybe_fold_offset_to_address (location_t loc, tree addr, tree offset,
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tree orig_type)
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{
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tree base, ret;
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STRIP_NOPS (addr);
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if (TREE_CODE (addr) != ADDR_EXPR)
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return NULL_TREE;
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base = TREE_OPERAND (addr, 0);
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ret = maybe_fold_offset_to_array_ref (loc, base, offset);
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if (ret)
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{
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ret = build_fold_addr_expr (ret);
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if (!useless_type_conversion_p (orig_type, TREE_TYPE (ret)))
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return NULL_TREE;
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SET_EXPR_LOCATION (ret, loc);
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}
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return ret;
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}
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/* A quaint feature extant in our address arithmetic is that there
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can be hidden type changes here. The type of the result need
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not be the same as the type of the input pointer.
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What we're after here is an expression of the form
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(T *)(&array + const)
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where array is OP0, const is OP1, RES_TYPE is T and
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the cast doesn't actually exist, but is implicit in the
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type of the POINTER_PLUS_EXPR. We'd like to turn this into
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&array[x]
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which may be able to propagate further. */
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tree
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maybe_fold_stmt_addition (location_t loc, tree res_type, tree op0, tree op1)
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{
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tree ptd_type;
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tree t;
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/* The first operand should be an ADDR_EXPR. */
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if (TREE_CODE (op0) != ADDR_EXPR)
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return NULL_TREE;
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op0 = TREE_OPERAND (op0, 0);
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/* It had better be a constant. */
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if (TREE_CODE (op1) != INTEGER_CST)
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{
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/* Or op0 should now be A[0] and the non-constant offset defined
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via a multiplication by the array element size. */
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if (TREE_CODE (op0) == ARRAY_REF
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/* As we will end up creating a variable index array access
|
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in the outermost array dimension make sure there isn't
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a more inner array that the index could overflow to. */
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&& TREE_CODE (TREE_OPERAND (op0, 0)) != ARRAY_REF
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&& integer_zerop (TREE_OPERAND (op0, 1))
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&& TREE_CODE (op1) == SSA_NAME)
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{
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gimple offset_def = SSA_NAME_DEF_STMT (op1);
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tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (op0));
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if (!host_integerp (elsz, 1)
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|| !is_gimple_assign (offset_def))
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return NULL_TREE;
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/* Do not build array references of something that we can't
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see the true number of array dimensions for. */
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if (!DECL_P (TREE_OPERAND (op0, 0))
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&& !handled_component_p (TREE_OPERAND (op0, 0)))
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return NULL_TREE;
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if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
|
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&& TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
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&& tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz))
|
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return build_fold_addr_expr
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(build4 (ARRAY_REF, TREE_TYPE (op0),
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TREE_OPERAND (op0, 0),
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gimple_assign_rhs1 (offset_def),
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TREE_OPERAND (op0, 2),
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TREE_OPERAND (op0, 3)));
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else if (integer_onep (elsz)
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&& gimple_assign_rhs_code (offset_def) != MULT_EXPR)
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return build_fold_addr_expr
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(build4 (ARRAY_REF, TREE_TYPE (op0),
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TREE_OPERAND (op0, 0),
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op1,
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TREE_OPERAND (op0, 2),
|
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TREE_OPERAND (op0, 3)));
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}
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else if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
|
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/* Dto. */
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&& TREE_CODE (TREE_TYPE (TREE_TYPE (op0))) != ARRAY_TYPE
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&& TREE_CODE (op1) == SSA_NAME)
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{
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gimple offset_def = SSA_NAME_DEF_STMT (op1);
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tree elsz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (op0)));
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if (!host_integerp (elsz, 1)
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|| !is_gimple_assign (offset_def))
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return NULL_TREE;
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|
|
/* Do not build array references of something that we can't
|
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see the true number of array dimensions for. */
|
|
if (!DECL_P (op0)
|
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&& !handled_component_p (op0))
|
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return NULL_TREE;
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|
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if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
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&& TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
|
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&& tree_int_cst_equal (gimple_assign_rhs2 (offset_def), elsz))
|
|
return build_fold_addr_expr
|
|
(build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)),
|
|
op0, gimple_assign_rhs1 (offset_def),
|
|
integer_zero_node, NULL_TREE));
|
|
else if (integer_onep (elsz)
|
|
&& gimple_assign_rhs_code (offset_def) != MULT_EXPR)
|
|
return build_fold_addr_expr
|
|
(build4 (ARRAY_REF, TREE_TYPE (TREE_TYPE (op0)),
|
|
op0, op1,
|
|
integer_zero_node, NULL_TREE));
|
|
}
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* If the first operand is an ARRAY_REF, expand it so that we can fold
|
|
the offset into it. */
|
|
while (TREE_CODE (op0) == ARRAY_REF)
|
|
{
|
|
tree array_obj = TREE_OPERAND (op0, 0);
|
|
tree array_idx = TREE_OPERAND (op0, 1);
|
|
tree elt_type = TREE_TYPE (op0);
|
|
tree elt_size = TYPE_SIZE_UNIT (elt_type);
|
|
tree min_idx;
|
|
|
|
if (TREE_CODE (array_idx) != INTEGER_CST)
|
|
break;
|
|
if (TREE_CODE (elt_size) != INTEGER_CST)
|
|
break;
|
|
|
|
/* Un-bias the index by the min index of the array type. */
|
|
min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj));
|
|
if (min_idx)
|
|
{
|
|
min_idx = TYPE_MIN_VALUE (min_idx);
|
|
if (min_idx)
|
|
{
|
|
if (TREE_CODE (min_idx) != INTEGER_CST)
|
|
break;
|
|
|
|
array_idx = fold_convert (TREE_TYPE (min_idx), array_idx);
|
|
if (!integer_zerop (min_idx))
|
|
array_idx = int_const_binop (MINUS_EXPR, array_idx,
|
|
min_idx);
|
|
}
|
|
}
|
|
|
|
/* Convert the index to a byte offset. */
|
|
array_idx = fold_convert (sizetype, array_idx);
|
|
array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size);
|
|
|
|
/* Update the operands for the next round, or for folding. */
|
|
op1 = int_const_binop (PLUS_EXPR,
|
|
array_idx, op1);
|
|
op0 = array_obj;
|
|
}
|
|
|
|
ptd_type = TREE_TYPE (res_type);
|
|
/* If we want a pointer to void, reconstruct the reference from the
|
|
array element type. A pointer to that can be trivially converted
|
|
to void *. This happens as we fold (void *)(ptr p+ off). */
|
|
if (VOID_TYPE_P (ptd_type)
|
|
&& TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
|
|
ptd_type = TREE_TYPE (TREE_TYPE (op0));
|
|
|
|
/* At which point we can try some of the same things as for indirects. */
|
|
t = maybe_fold_offset_to_array_ref (loc, op0, op1);
|
|
if (t)
|
|
{
|
|
t = build_fold_addr_expr (t);
|
|
if (!useless_type_conversion_p (res_type, TREE_TYPE (t)))
|
|
return NULL_TREE;
|
|
SET_EXPR_LOCATION (t, loc);
|
|
}
|
|
|
|
return t;
|
|
}
|
|
|
|
/* Subroutine of fold_stmt. We perform several simplifications of the
|
|
memory reference tree EXPR and make sure to re-gimplify them properly
|
|
after propagation of constant addresses. IS_LHS is true if the
|
|
reference is supposed to be an lvalue. */
|
|
|
|
static tree
|
|
maybe_fold_reference (tree expr, bool is_lhs)
|
|
{
|
|
tree *t = &expr;
|
|
tree result;
|
|
|
|
if ((TREE_CODE (expr) == VIEW_CONVERT_EXPR
|
|
|| TREE_CODE (expr) == REALPART_EXPR
|
|
|| TREE_CODE (expr) == IMAGPART_EXPR)
|
|
&& CONSTANT_CLASS_P (TREE_OPERAND (expr, 0)))
|
|
return fold_unary_loc (EXPR_LOCATION (expr),
|
|
TREE_CODE (expr),
|
|
TREE_TYPE (expr),
|
|
TREE_OPERAND (expr, 0));
|
|
else if (TREE_CODE (expr) == BIT_FIELD_REF
|
|
&& CONSTANT_CLASS_P (TREE_OPERAND (expr, 0)))
|
|
return fold_ternary_loc (EXPR_LOCATION (expr),
|
|
TREE_CODE (expr),
|
|
TREE_TYPE (expr),
|
|
TREE_OPERAND (expr, 0),
|
|
TREE_OPERAND (expr, 1),
|
|
TREE_OPERAND (expr, 2));
|
|
|
|
while (handled_component_p (*t))
|
|
t = &TREE_OPERAND (*t, 0);
|
|
|
|
/* Canonicalize MEM_REFs invariant address operand. Do this first
|
|
to avoid feeding non-canonical MEM_REFs elsewhere. */
|
|
if (TREE_CODE (*t) == MEM_REF
|
|
&& !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0)))
|
|
{
|
|
bool volatile_p = TREE_THIS_VOLATILE (*t);
|
|
tree tem = fold_binary (MEM_REF, TREE_TYPE (*t),
|
|
TREE_OPERAND (*t, 0),
|
|
TREE_OPERAND (*t, 1));
|
|
if (tem)
|
|
{
|
|
TREE_THIS_VOLATILE (tem) = volatile_p;
|
|
*t = tem;
|
|
tem = maybe_fold_reference (expr, is_lhs);
|
|
if (tem)
|
|
return tem;
|
|
return expr;
|
|
}
|
|
}
|
|
|
|
if (!is_lhs
|
|
&& (result = fold_const_aggregate_ref (expr))
|
|
&& is_gimple_min_invariant (result))
|
|
return result;
|
|
|
|
/* Fold back MEM_REFs to reference trees. */
|
|
if (TREE_CODE (*t) == MEM_REF
|
|
&& TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR
|
|
&& integer_zerop (TREE_OPERAND (*t, 1))
|
|
&& (TREE_THIS_VOLATILE (*t)
|
|
== TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0)))
|
|
&& !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1)))
|
|
&& (TYPE_MAIN_VARIANT (TREE_TYPE (*t))
|
|
== TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1)))))
|
|
/* We have to look out here to not drop a required conversion
|
|
from the rhs to the lhs if is_lhs, but we don't have the
|
|
rhs here to verify that. Thus require strict type
|
|
compatibility. */
|
|
&& types_compatible_p (TREE_TYPE (*t),
|
|
TREE_TYPE (TREE_OPERAND
|
|
(TREE_OPERAND (*t, 0), 0))))
|
|
{
|
|
tree tem;
|
|
*t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0);
|
|
tem = maybe_fold_reference (expr, is_lhs);
|
|
if (tem)
|
|
return tem;
|
|
return expr;
|
|
}
|
|
else if (TREE_CODE (*t) == TARGET_MEM_REF)
|
|
{
|
|
tree tem = maybe_fold_tmr (*t);
|
|
if (tem)
|
|
{
|
|
*t = tem;
|
|
tem = maybe_fold_reference (expr, is_lhs);
|
|
if (tem)
|
|
return tem;
|
|
return expr;
|
|
}
|
|
}
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
|
|
/* Attempt to fold an assignment statement pointed-to by SI. Returns a
|
|
replacement rhs for the statement or NULL_TREE if no simplification
|
|
could be made. It is assumed that the operands have been previously
|
|
folded. */
|
|
|
|
static tree
|
|
fold_gimple_assign (gimple_stmt_iterator *si)
|
|
{
|
|
gimple stmt = gsi_stmt (*si);
|
|
enum tree_code subcode = gimple_assign_rhs_code (stmt);
|
|
location_t loc = gimple_location (stmt);
|
|
|
|
tree result = NULL_TREE;
|
|
|
|
switch (get_gimple_rhs_class (subcode))
|
|
{
|
|
case GIMPLE_SINGLE_RHS:
|
|
{
|
|
tree rhs = gimple_assign_rhs1 (stmt);
|
|
|
|
/* Try to fold a conditional expression. */
|
|
if (TREE_CODE (rhs) == COND_EXPR)
|
|
{
|
|
tree op0 = COND_EXPR_COND (rhs);
|
|
tree tem;
|
|
bool set = false;
|
|
location_t cond_loc = EXPR_LOCATION (rhs);
|
|
|
|
if (COMPARISON_CLASS_P (op0))
|
|
{
|
|
fold_defer_overflow_warnings ();
|
|
tem = fold_binary_loc (cond_loc,
|
|
TREE_CODE (op0), TREE_TYPE (op0),
|
|
TREE_OPERAND (op0, 0),
|
|
TREE_OPERAND (op0, 1));
|
|
/* This is actually a conditional expression, not a GIMPLE
|
|
conditional statement, however, the valid_gimple_rhs_p
|
|
test still applies. */
|
|
set = (tem && is_gimple_condexpr (tem)
|
|
&& valid_gimple_rhs_p (tem));
|
|
fold_undefer_overflow_warnings (set, stmt, 0);
|
|
}
|
|
else if (is_gimple_min_invariant (op0))
|
|
{
|
|
tem = op0;
|
|
set = true;
|
|
}
|
|
else
|
|
return NULL_TREE;
|
|
|
|
if (set)
|
|
result = fold_build3_loc (cond_loc, COND_EXPR, TREE_TYPE (rhs), tem,
|
|
COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs));
|
|
}
|
|
|
|
else if (REFERENCE_CLASS_P (rhs))
|
|
return maybe_fold_reference (rhs, false);
|
|
|
|
else if (TREE_CODE (rhs) == ADDR_EXPR)
|
|
{
|
|
tree ref = TREE_OPERAND (rhs, 0);
|
|
tree tem = maybe_fold_reference (ref, true);
|
|
if (tem
|
|
&& TREE_CODE (tem) == MEM_REF
|
|
&& integer_zerop (TREE_OPERAND (tem, 1)))
|
|
result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0));
|
|
else if (tem)
|
|
result = fold_convert (TREE_TYPE (rhs),
|
|
build_fold_addr_expr_loc (loc, tem));
|
|
else if (TREE_CODE (ref) == MEM_REF
|
|
&& integer_zerop (TREE_OPERAND (ref, 1)))
|
|
result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0));
|
|
}
|
|
|
|
else if (TREE_CODE (rhs) == CONSTRUCTOR
|
|
&& TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE
|
|
&& (CONSTRUCTOR_NELTS (rhs)
|
|
== TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))))
|
|
{
|
|
/* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */
|
|
unsigned i;
|
|
tree val;
|
|
|
|
FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val)
|
|
if (TREE_CODE (val) != INTEGER_CST
|
|
&& TREE_CODE (val) != REAL_CST
|
|
&& TREE_CODE (val) != FIXED_CST)
|
|
return NULL_TREE;
|
|
|
|
return build_vector_from_ctor (TREE_TYPE (rhs),
|
|
CONSTRUCTOR_ELTS (rhs));
|
|
}
|
|
|
|
else if (DECL_P (rhs))
|
|
return unshare_expr (get_symbol_constant_value (rhs));
|
|
|
|
/* If we couldn't fold the RHS, hand over to the generic
|
|
fold routines. */
|
|
if (result == NULL_TREE)
|
|
result = fold (rhs);
|
|
|
|
/* Strip away useless type conversions. Both the NON_LVALUE_EXPR
|
|
that may have been added by fold, and "useless" type
|
|
conversions that might now be apparent due to propagation. */
|
|
STRIP_USELESS_TYPE_CONVERSION (result);
|
|
|
|
if (result != rhs && valid_gimple_rhs_p (result))
|
|
return result;
|
|
|
|
return NULL_TREE;
|
|
}
|
|
break;
|
|
|
|
case GIMPLE_UNARY_RHS:
|
|
{
|
|
tree rhs = gimple_assign_rhs1 (stmt);
|
|
|
|
result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs);
|
|
if (result)
|
|
{
|
|
/* If the operation was a conversion do _not_ mark a
|
|
resulting constant with TREE_OVERFLOW if the original
|
|
constant was not. These conversions have implementation
|
|
defined behavior and retaining the TREE_OVERFLOW flag
|
|
here would confuse later passes such as VRP. */
|
|
if (CONVERT_EXPR_CODE_P (subcode)
|
|
&& TREE_CODE (result) == INTEGER_CST
|
|
&& TREE_CODE (rhs) == INTEGER_CST)
|
|
TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs);
|
|
|
|
STRIP_USELESS_TYPE_CONVERSION (result);
|
|
if (valid_gimple_rhs_p (result))
|
|
return result;
|
|
}
|
|
else if (CONVERT_EXPR_CODE_P (subcode)
|
|
&& POINTER_TYPE_P (gimple_expr_type (stmt))
|
|
&& POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))
|
|
{
|
|
tree type = gimple_expr_type (stmt);
|
|
tree t = maybe_fold_offset_to_address (loc,
|
|
gimple_assign_rhs1 (stmt),
|
|
integer_zero_node, type);
|
|
if (t)
|
|
return t;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case GIMPLE_BINARY_RHS:
|
|
/* Try to fold pointer addition. */
|
|
if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
|
|
{
|
|
tree type = TREE_TYPE (gimple_assign_rhs1 (stmt));
|
|
if (TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE)
|
|
{
|
|
type = build_pointer_type (TREE_TYPE (TREE_TYPE (type)));
|
|
if (!useless_type_conversion_p
|
|
(TREE_TYPE (gimple_assign_lhs (stmt)), type))
|
|
type = TREE_TYPE (gimple_assign_rhs1 (stmt));
|
|
}
|
|
result = maybe_fold_stmt_addition (gimple_location (stmt),
|
|
type,
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt));
|
|
}
|
|
|
|
if (!result)
|
|
result = fold_binary_loc (loc, subcode,
|
|
TREE_TYPE (gimple_assign_lhs (stmt)),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt));
|
|
|
|
if (result)
|
|
{
|
|
STRIP_USELESS_TYPE_CONVERSION (result);
|
|
if (valid_gimple_rhs_p (result))
|
|
return result;
|
|
|
|
/* Fold might have produced non-GIMPLE, so if we trust it blindly
|
|
we lose canonicalization opportunities. Do not go again
|
|
through fold here though, or the same non-GIMPLE will be
|
|
produced. */
|
|
if (commutative_tree_code (subcode)
|
|
&& tree_swap_operands_p (gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt), false))
|
|
return build2 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)),
|
|
gimple_assign_rhs2 (stmt),
|
|
gimple_assign_rhs1 (stmt));
|
|
}
|
|
break;
|
|
|
|
case GIMPLE_TERNARY_RHS:
|
|
result = fold_ternary_loc (loc, subcode,
|
|
TREE_TYPE (gimple_assign_lhs (stmt)),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt),
|
|
gimple_assign_rhs3 (stmt));
|
|
|
|
if (result)
|
|
{
|
|
STRIP_USELESS_TYPE_CONVERSION (result);
|
|
if (valid_gimple_rhs_p (result))
|
|
return result;
|
|
|
|
/* Fold might have produced non-GIMPLE, so if we trust it blindly
|
|
we lose canonicalization opportunities. Do not go again
|
|
through fold here though, or the same non-GIMPLE will be
|
|
produced. */
|
|
if (commutative_ternary_tree_code (subcode)
|
|
&& tree_swap_operands_p (gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt), false))
|
|
return build3 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)),
|
|
gimple_assign_rhs2 (stmt),
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs3 (stmt));
|
|
}
|
|
break;
|
|
|
|
case GIMPLE_INVALID_RHS:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Attempt to fold a conditional statement. Return true if any changes were
|
|
made. We only attempt to fold the condition expression, and do not perform
|
|
any transformation that would require alteration of the cfg. It is
|
|
assumed that the operands have been previously folded. */
|
|
|
|
static bool
|
|
fold_gimple_cond (gimple stmt)
|
|
{
|
|
tree result = fold_binary_loc (gimple_location (stmt),
|
|
gimple_cond_code (stmt),
|
|
boolean_type_node,
|
|
gimple_cond_lhs (stmt),
|
|
gimple_cond_rhs (stmt));
|
|
|
|
if (result)
|
|
{
|
|
STRIP_USELESS_TYPE_CONVERSION (result);
|
|
if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result))
|
|
{
|
|
gimple_cond_set_condition_from_tree (stmt, result);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Convert EXPR into a GIMPLE value suitable for substitution on the
|
|
RHS of an assignment. Insert the necessary statements before
|
|
iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL
|
|
is replaced. If the call is expected to produces a result, then it
|
|
is replaced by an assignment of the new RHS to the result variable.
|
|
If the result is to be ignored, then the call is replaced by a
|
|
GIMPLE_NOP. A proper VDEF chain is retained by making the first
|
|
VUSE and the last VDEF of the whole sequence be the same as the replaced
|
|
statement and using new SSA names for stores in between. */
|
|
|
|
void
|
|
gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr)
|
|
{
|
|
tree lhs;
|
|
tree tmp = NULL_TREE; /* Silence warning. */
|
|
gimple stmt, new_stmt;
|
|
gimple_stmt_iterator i;
|
|
gimple_seq stmts = gimple_seq_alloc();
|
|
struct gimplify_ctx gctx;
|
|
gimple last = NULL;
|
|
gimple laststore = NULL;
|
|
tree reaching_vuse;
|
|
|
|
stmt = gsi_stmt (*si_p);
|
|
|
|
gcc_assert (is_gimple_call (stmt));
|
|
|
|
lhs = gimple_call_lhs (stmt);
|
|
reaching_vuse = gimple_vuse (stmt);
|
|
|
|
push_gimplify_context (&gctx);
|
|
|
|
if (lhs == NULL_TREE)
|
|
{
|
|
gimplify_and_add (expr, &stmts);
|
|
/* We can end up with folding a memcpy of an empty class assignment
|
|
which gets optimized away by C++ gimplification. */
|
|
if (gimple_seq_empty_p (stmts))
|
|
{
|
|
pop_gimplify_context (NULL);
|
|
if (gimple_in_ssa_p (cfun))
|
|
{
|
|
unlink_stmt_vdef (stmt);
|
|
release_defs (stmt);
|
|
}
|
|
gsi_remove (si_p, true);
|
|
return;
|
|
}
|
|
}
|
|
else
|
|
tmp = get_initialized_tmp_var (expr, &stmts, NULL);
|
|
|
|
pop_gimplify_context (NULL);
|
|
|
|
if (gimple_has_location (stmt))
|
|
annotate_all_with_location (stmts, gimple_location (stmt));
|
|
|
|
/* The replacement can expose previously unreferenced variables. */
|
|
for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i))
|
|
{
|
|
if (last)
|
|
{
|
|
gsi_insert_before (si_p, last, GSI_NEW_STMT);
|
|
gsi_next (si_p);
|
|
}
|
|
new_stmt = gsi_stmt (i);
|
|
if (gimple_in_ssa_p (cfun))
|
|
{
|
|
find_new_referenced_vars (new_stmt);
|
|
mark_symbols_for_renaming (new_stmt);
|
|
}
|
|
/* If the new statement has a VUSE, update it with exact SSA name we
|
|
know will reach this one. */
|
|
if (gimple_vuse (new_stmt))
|
|
{
|
|
/* If we've also seen a previous store create a new VDEF for
|
|
the latter one, and make that the new reaching VUSE. */
|
|
if (laststore)
|
|
{
|
|
reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore);
|
|
gimple_set_vdef (laststore, reaching_vuse);
|
|
update_stmt (laststore);
|
|
laststore = NULL;
|
|
}
|
|
gimple_set_vuse (new_stmt, reaching_vuse);
|
|
gimple_set_modified (new_stmt, true);
|
|
}
|
|
if (gimple_assign_single_p (new_stmt)
|
|
&& !is_gimple_reg (gimple_assign_lhs (new_stmt)))
|
|
{
|
|
laststore = new_stmt;
|
|
}
|
|
last = new_stmt;
|
|
}
|
|
|
|
if (lhs == NULL_TREE)
|
|
{
|
|
/* If we replace a call without LHS that has a VDEF and our new
|
|
sequence ends with a store we must make that store have the same
|
|
vdef in order not to break the sequencing. This can happen
|
|
for instance when folding memcpy calls into assignments. */
|
|
if (gimple_vdef (stmt) && laststore)
|
|
{
|
|
gimple_set_vdef (laststore, gimple_vdef (stmt));
|
|
if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
|
|
SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore;
|
|
update_stmt (laststore);
|
|
}
|
|
else if (gimple_in_ssa_p (cfun))
|
|
{
|
|
unlink_stmt_vdef (stmt);
|
|
release_defs (stmt);
|
|
}
|
|
new_stmt = last;
|
|
}
|
|
else
|
|
{
|
|
if (last)
|
|
{
|
|
gsi_insert_before (si_p, last, GSI_NEW_STMT);
|
|
gsi_next (si_p);
|
|
}
|
|
if (laststore && is_gimple_reg (lhs))
|
|
{
|
|
gimple_set_vdef (laststore, gimple_vdef (stmt));
|
|
update_stmt (laststore);
|
|
if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
|
|
SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = laststore;
|
|
laststore = NULL;
|
|
}
|
|
else if (laststore)
|
|
{
|
|
reaching_vuse = make_ssa_name (gimple_vop (cfun), laststore);
|
|
gimple_set_vdef (laststore, reaching_vuse);
|
|
update_stmt (laststore);
|
|
laststore = NULL;
|
|
}
|
|
new_stmt = gimple_build_assign (lhs, tmp);
|
|
if (!is_gimple_reg (tmp))
|
|
gimple_set_vuse (new_stmt, reaching_vuse);
|
|
if (!is_gimple_reg (lhs))
|
|
{
|
|
gimple_set_vdef (new_stmt, gimple_vdef (stmt));
|
|
if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
|
|
SSA_NAME_DEF_STMT (gimple_vdef (stmt)) = new_stmt;
|
|
}
|
|
else if (reaching_vuse == gimple_vuse (stmt))
|
|
unlink_stmt_vdef (stmt);
|
|
}
|
|
|
|
gimple_set_location (new_stmt, gimple_location (stmt));
|
|
gsi_replace (si_p, new_stmt, false);
|
|
}
|
|
|
|
/* Return the string length, maximum string length or maximum value of
|
|
ARG in LENGTH.
|
|
If ARG is an SSA name variable, follow its use-def chains. If LENGTH
|
|
is not NULL and, for TYPE == 0, its value is not equal to the length
|
|
we determine or if we are unable to determine the length or value,
|
|
return false. VISITED is a bitmap of visited variables.
|
|
TYPE is 0 if string length should be returned, 1 for maximum string
|
|
length and 2 for maximum value ARG can have. */
|
|
|
|
static bool
|
|
get_maxval_strlen (tree arg, tree *length, bitmap visited, int type)
|
|
{
|
|
tree var, val;
|
|
gimple def_stmt;
|
|
|
|
if (TREE_CODE (arg) != SSA_NAME)
|
|
{
|
|
if (TREE_CODE (arg) == COND_EXPR)
|
|
return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type)
|
|
&& get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type);
|
|
/* We can end up with &(*iftmp_1)[0] here as well, so handle it. */
|
|
else if (TREE_CODE (arg) == ADDR_EXPR
|
|
&& TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF
|
|
&& integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1)))
|
|
{
|
|
tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0);
|
|
if (TREE_CODE (aop0) == INDIRECT_REF
|
|
&& TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME)
|
|
return get_maxval_strlen (TREE_OPERAND (aop0, 0),
|
|
length, visited, type);
|
|
}
|
|
|
|
if (type == 2)
|
|
{
|
|
val = arg;
|
|
if (TREE_CODE (val) != INTEGER_CST
|
|
|| tree_int_cst_sgn (val) < 0)
|
|
return false;
|
|
}
|
|
else
|
|
val = c_strlen (arg, 1);
|
|
if (!val)
|
|
return false;
|
|
|
|
if (*length)
|
|
{
|
|
if (type > 0)
|
|
{
|
|
if (TREE_CODE (*length) != INTEGER_CST
|
|
|| TREE_CODE (val) != INTEGER_CST)
|
|
return false;
|
|
|
|
if (tree_int_cst_lt (*length, val))
|
|
*length = val;
|
|
return true;
|
|
}
|
|
else if (simple_cst_equal (val, *length) != 1)
|
|
return false;
|
|
}
|
|
|
|
*length = val;
|
|
return true;
|
|
}
|
|
|
|
/* If we were already here, break the infinite cycle. */
|
|
if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg)))
|
|
return true;
|
|
|
|
var = arg;
|
|
def_stmt = SSA_NAME_DEF_STMT (var);
|
|
|
|
switch (gimple_code (def_stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
/* The RHS of the statement defining VAR must either have a
|
|
constant length or come from another SSA_NAME with a constant
|
|
length. */
|
|
if (gimple_assign_single_p (def_stmt)
|
|
|| gimple_assign_unary_nop_p (def_stmt))
|
|
{
|
|
tree rhs = gimple_assign_rhs1 (def_stmt);
|
|
return get_maxval_strlen (rhs, length, visited, type);
|
|
}
|
|
return false;
|
|
|
|
case GIMPLE_PHI:
|
|
{
|
|
/* All the arguments of the PHI node must have the same constant
|
|
length. */
|
|
unsigned i;
|
|
|
|
for (i = 0; i < gimple_phi_num_args (def_stmt); i++)
|
|
{
|
|
tree arg = gimple_phi_arg (def_stmt, i)->def;
|
|
|
|
/* If this PHI has itself as an argument, we cannot
|
|
determine the string length of this argument. However,
|
|
if we can find a constant string length for the other
|
|
PHI args then we can still be sure that this is a
|
|
constant string length. So be optimistic and just
|
|
continue with the next argument. */
|
|
if (arg == gimple_phi_result (def_stmt))
|
|
continue;
|
|
|
|
if (!get_maxval_strlen (arg, length, visited, type))
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
|
|
/* Fold builtin call in statement STMT. Returns a simplified tree.
|
|
We may return a non-constant expression, including another call
|
|
to a different function and with different arguments, e.g.,
|
|
substituting memcpy for strcpy when the string length is known.
|
|
Note that some builtins expand into inline code that may not
|
|
be valid in GIMPLE. Callers must take care. */
|
|
|
|
tree
|
|
gimple_fold_builtin (gimple stmt)
|
|
{
|
|
tree result, val[3];
|
|
tree callee, a;
|
|
int arg_idx, type;
|
|
bitmap visited;
|
|
bool ignore;
|
|
int nargs;
|
|
location_t loc = gimple_location (stmt);
|
|
|
|
gcc_assert (is_gimple_call (stmt));
|
|
|
|
ignore = (gimple_call_lhs (stmt) == NULL);
|
|
|
|
/* First try the generic builtin folder. If that succeeds, return the
|
|
result directly. */
|
|
result = fold_call_stmt (stmt, ignore);
|
|
if (result)
|
|
{
|
|
if (ignore)
|
|
STRIP_NOPS (result);
|
|
return result;
|
|
}
|
|
|
|
/* Ignore MD builtins. */
|
|
callee = gimple_call_fndecl (stmt);
|
|
if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD)
|
|
return NULL_TREE;
|
|
|
|
/* If the builtin could not be folded, and it has no argument list,
|
|
we're done. */
|
|
nargs = gimple_call_num_args (stmt);
|
|
if (nargs == 0)
|
|
return NULL_TREE;
|
|
|
|
/* Limit the work only for builtins we know how to simplify. */
|
|
switch (DECL_FUNCTION_CODE (callee))
|
|
{
|
|
case BUILT_IN_STRLEN:
|
|
case BUILT_IN_FPUTS:
|
|
case BUILT_IN_FPUTS_UNLOCKED:
|
|
arg_idx = 0;
|
|
type = 0;
|
|
break;
|
|
case BUILT_IN_STRCPY:
|
|
case BUILT_IN_STRNCPY:
|
|
arg_idx = 1;
|
|
type = 0;
|
|
break;
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
case BUILT_IN_MEMPCPY_CHK:
|
|
case BUILT_IN_MEMMOVE_CHK:
|
|
case BUILT_IN_MEMSET_CHK:
|
|
case BUILT_IN_STRNCPY_CHK:
|
|
arg_idx = 2;
|
|
type = 2;
|
|
break;
|
|
case BUILT_IN_STRCPY_CHK:
|
|
case BUILT_IN_STPCPY_CHK:
|
|
arg_idx = 1;
|
|
type = 1;
|
|
break;
|
|
case BUILT_IN_SNPRINTF_CHK:
|
|
case BUILT_IN_VSNPRINTF_CHK:
|
|
arg_idx = 1;
|
|
type = 2;
|
|
break;
|
|
default:
|
|
return NULL_TREE;
|
|
}
|
|
|
|
if (arg_idx >= nargs)
|
|
return NULL_TREE;
|
|
|
|
/* Try to use the dataflow information gathered by the CCP process. */
|
|
visited = BITMAP_ALLOC (NULL);
|
|
bitmap_clear (visited);
|
|
|
|
memset (val, 0, sizeof (val));
|
|
a = gimple_call_arg (stmt, arg_idx);
|
|
if (!get_maxval_strlen (a, &val[arg_idx], visited, type))
|
|
val[arg_idx] = NULL_TREE;
|
|
|
|
BITMAP_FREE (visited);
|
|
|
|
result = NULL_TREE;
|
|
switch (DECL_FUNCTION_CODE (callee))
|
|
{
|
|
case BUILT_IN_STRLEN:
|
|
if (val[0] && nargs == 1)
|
|
{
|
|
tree new_val =
|
|
fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]);
|
|
|
|
/* If the result is not a valid gimple value, or not a cast
|
|
of a valid gimple value, then we cannot use the result. */
|
|
if (is_gimple_val (new_val)
|
|
|| (CONVERT_EXPR_P (new_val)
|
|
&& is_gimple_val (TREE_OPERAND (new_val, 0))))
|
|
return new_val;
|
|
}
|
|
break;
|
|
|
|
case BUILT_IN_STRCPY:
|
|
if (val[1] && is_gimple_val (val[1]) && nargs == 2)
|
|
result = fold_builtin_strcpy (loc, callee,
|
|
gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
val[1]);
|
|
break;
|
|
|
|
case BUILT_IN_STRNCPY:
|
|
if (val[1] && is_gimple_val (val[1]) && nargs == 3)
|
|
result = fold_builtin_strncpy (loc, callee,
|
|
gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
gimple_call_arg (stmt, 2),
|
|
val[1]);
|
|
break;
|
|
|
|
case BUILT_IN_FPUTS:
|
|
if (nargs == 2)
|
|
result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
ignore, false, val[0]);
|
|
break;
|
|
|
|
case BUILT_IN_FPUTS_UNLOCKED:
|
|
if (nargs == 2)
|
|
result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
ignore, true, val[0]);
|
|
break;
|
|
|
|
case BUILT_IN_MEMCPY_CHK:
|
|
case BUILT_IN_MEMPCPY_CHK:
|
|
case BUILT_IN_MEMMOVE_CHK:
|
|
case BUILT_IN_MEMSET_CHK:
|
|
if (val[2] && is_gimple_val (val[2]) && nargs == 4)
|
|
result = fold_builtin_memory_chk (loc, callee,
|
|
gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
gimple_call_arg (stmt, 2),
|
|
gimple_call_arg (stmt, 3),
|
|
val[2], ignore,
|
|
DECL_FUNCTION_CODE (callee));
|
|
break;
|
|
|
|
case BUILT_IN_STRCPY_CHK:
|
|
case BUILT_IN_STPCPY_CHK:
|
|
if (val[1] && is_gimple_val (val[1]) && nargs == 3)
|
|
result = fold_builtin_stxcpy_chk (loc, callee,
|
|
gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
gimple_call_arg (stmt, 2),
|
|
val[1], ignore,
|
|
DECL_FUNCTION_CODE (callee));
|
|
break;
|
|
|
|
case BUILT_IN_STRNCPY_CHK:
|
|
if (val[2] && is_gimple_val (val[2]) && nargs == 4)
|
|
result = fold_builtin_strncpy_chk (loc, gimple_call_arg (stmt, 0),
|
|
gimple_call_arg (stmt, 1),
|
|
gimple_call_arg (stmt, 2),
|
|
gimple_call_arg (stmt, 3),
|
|
val[2]);
|
|
break;
|
|
|
|
case BUILT_IN_SNPRINTF_CHK:
|
|
case BUILT_IN_VSNPRINTF_CHK:
|
|
if (val[1] && is_gimple_val (val[1]))
|
|
result = gimple_fold_builtin_snprintf_chk (stmt, val[1],
|
|
DECL_FUNCTION_CODE (callee));
|
|
break;
|
|
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
|
|
if (result && ignore)
|
|
result = fold_ignored_result (result);
|
|
return result;
|
|
}
|
|
|
|
/* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN
|
|
is integer form of OBJ_TYPE_REF_TOKEN of the reference expression.
|
|
KNOWN_BINFO carries the binfo describing the true type of
|
|
OBJ_TYPE_REF_OBJECT(REF). If a call to the function must be accompanied
|
|
with a this adjustment, the constant which should be added to this pointer
|
|
is stored to *DELTA. If REFUSE_THUNKS is true, return NULL if the function
|
|
is a thunk (other than a this adjustment which is dealt with by DELTA). */
|
|
|
|
tree
|
|
gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo,
|
|
tree *delta)
|
|
{
|
|
HOST_WIDE_INT i;
|
|
tree v, fndecl;
|
|
|
|
v = BINFO_VIRTUALS (known_binfo);
|
|
/* If there is no virtual methods leave the OBJ_TYPE_REF alone. */
|
|
if (!v)
|
|
return NULL_TREE;
|
|
i = 0;
|
|
while (i != token)
|
|
{
|
|
i += (TARGET_VTABLE_USES_DESCRIPTORS
|
|
? TARGET_VTABLE_USES_DESCRIPTORS : 1);
|
|
v = TREE_CHAIN (v);
|
|
}
|
|
|
|
/* If BV_VCALL_INDEX is non-NULL, give up. */
|
|
if (TREE_TYPE (v))
|
|
return NULL_TREE;
|
|
|
|
fndecl = TREE_VALUE (v);
|
|
|
|
/* When cgraph node is missing and function is not public, we cannot
|
|
devirtualize. This can happen in WHOPR when the actual method
|
|
ends up in other partition, because we found devirtualization
|
|
possibility too late. */
|
|
if (!can_refer_decl_in_current_unit_p (TREE_VALUE (v)))
|
|
return NULL_TREE;
|
|
|
|
*delta = TREE_PURPOSE (v);
|
|
gcc_checking_assert (host_integerp (*delta, 0));
|
|
return fndecl;
|
|
}
|
|
|
|
/* Generate code adjusting the first parameter of a call statement determined
|
|
by GSI by DELTA. */
|
|
|
|
void
|
|
gimple_adjust_this_by_delta (gimple_stmt_iterator *gsi, tree delta)
|
|
{
|
|
gimple call_stmt = gsi_stmt (*gsi);
|
|
tree parm, tmp;
|
|
gimple new_stmt;
|
|
|
|
delta = fold_convert (sizetype, delta);
|
|
gcc_assert (gimple_call_num_args (call_stmt) >= 1);
|
|
parm = gimple_call_arg (call_stmt, 0);
|
|
gcc_assert (POINTER_TYPE_P (TREE_TYPE (parm)));
|
|
tmp = create_tmp_var (TREE_TYPE (parm), NULL);
|
|
add_referenced_var (tmp);
|
|
|
|
tmp = make_ssa_name (tmp, NULL);
|
|
new_stmt = gimple_build_assign_with_ops (POINTER_PLUS_EXPR, tmp, parm, delta);
|
|
SSA_NAME_DEF_STMT (tmp) = new_stmt;
|
|
gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
|
|
gimple_call_set_arg (call_stmt, 0, tmp);
|
|
}
|
|
|
|
/* Return a binfo to be used for devirtualization of calls based on an object
|
|
represented by a declaration (i.e. a global or automatically allocated one)
|
|
or NULL if it cannot be found or is not safe. CST is expected to be an
|
|
ADDR_EXPR of such object or the function will return NULL. Currently it is
|
|
safe to use such binfo only if it has no base binfo (i.e. no ancestors). */
|
|
|
|
tree
|
|
gimple_extract_devirt_binfo_from_cst (tree cst)
|
|
{
|
|
HOST_WIDE_INT offset, size, max_size;
|
|
tree base, type, expected_type, binfo;
|
|
bool last_artificial = false;
|
|
|
|
if (!flag_devirtualize
|
|
|| TREE_CODE (cst) != ADDR_EXPR
|
|
|| TREE_CODE (TREE_TYPE (TREE_TYPE (cst))) != RECORD_TYPE)
|
|
return NULL_TREE;
|
|
|
|
cst = TREE_OPERAND (cst, 0);
|
|
expected_type = TREE_TYPE (cst);
|
|
base = get_ref_base_and_extent (cst, &offset, &size, &max_size);
|
|
type = TREE_TYPE (base);
|
|
if (!DECL_P (base)
|
|
|| max_size == -1
|
|
|| max_size != size
|
|
|| TREE_CODE (type) != RECORD_TYPE)
|
|
return NULL_TREE;
|
|
|
|
/* Find the sub-object the constant actually refers to and mark whether it is
|
|
an artificial one (as opposed to a user-defined one). */
|
|
while (true)
|
|
{
|
|
HOST_WIDE_INT pos, size;
|
|
tree fld;
|
|
|
|
if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (expected_type))
|
|
break;
|
|
if (offset < 0)
|
|
return NULL_TREE;
|
|
|
|
for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld))
|
|
{
|
|
if (TREE_CODE (fld) != FIELD_DECL)
|
|
continue;
|
|
|
|
pos = int_bit_position (fld);
|
|
size = tree_low_cst (DECL_SIZE (fld), 1);
|
|
if (pos <= offset && (pos + size) > offset)
|
|
break;
|
|
}
|
|
if (!fld || TREE_CODE (TREE_TYPE (fld)) != RECORD_TYPE)
|
|
return NULL_TREE;
|
|
|
|
last_artificial = DECL_ARTIFICIAL (fld);
|
|
type = TREE_TYPE (fld);
|
|
offset -= pos;
|
|
}
|
|
/* Artifical sub-objects are ancestors, we do not want to use them for
|
|
devirtualization, at least not here. */
|
|
if (last_artificial)
|
|
return NULL_TREE;
|
|
binfo = TYPE_BINFO (type);
|
|
if (!binfo || BINFO_N_BASE_BINFOS (binfo) > 0)
|
|
return NULL_TREE;
|
|
else
|
|
return binfo;
|
|
}
|
|
|
|
/* Attempt to fold a call statement referenced by the statement iterator GSI.
|
|
The statement may be replaced by another statement, e.g., if the call
|
|
simplifies to a constant value. Return true if any changes were made.
|
|
It is assumed that the operands have been previously folded. */
|
|
|
|
bool
|
|
gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace)
|
|
{
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
tree callee;
|
|
|
|
/* Check for builtins that CCP can handle using information not
|
|
available in the generic fold routines. */
|
|
callee = gimple_call_fndecl (stmt);
|
|
if (!inplace && callee && DECL_BUILT_IN (callee))
|
|
{
|
|
tree result = gimple_fold_builtin (stmt);
|
|
|
|
if (result)
|
|
{
|
|
if (!update_call_from_tree (gsi, result))
|
|
gimplify_and_update_call_from_tree (gsi, result);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/* Check for virtual calls that became direct calls. */
|
|
callee = gimple_call_fn (stmt);
|
|
if (callee && TREE_CODE (callee) == OBJ_TYPE_REF)
|
|
{
|
|
tree binfo, fndecl, delta, obj;
|
|
HOST_WIDE_INT token;
|
|
|
|
if (gimple_call_addr_fndecl (OBJ_TYPE_REF_EXPR (callee)) != NULL_TREE)
|
|
{
|
|
gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee));
|
|
return true;
|
|
}
|
|
|
|
obj = OBJ_TYPE_REF_OBJECT (callee);
|
|
binfo = gimple_extract_devirt_binfo_from_cst (obj);
|
|
if (!binfo)
|
|
return false;
|
|
token = TREE_INT_CST_LOW (OBJ_TYPE_REF_TOKEN (callee));
|
|
fndecl = gimple_get_virt_method_for_binfo (token, binfo, &delta);
|
|
if (!fndecl)
|
|
return false;
|
|
gcc_assert (integer_zerop (delta));
|
|
gimple_call_set_fndecl (stmt, fndecl);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument
|
|
distinguishes both cases. */
|
|
|
|
static bool
|
|
fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace)
|
|
{
|
|
bool changed = false;
|
|
gimple stmt = gsi_stmt (*gsi);
|
|
unsigned i;
|
|
gimple_stmt_iterator gsinext = *gsi;
|
|
gimple next_stmt;
|
|
|
|
gsi_next (&gsinext);
|
|
next_stmt = gsi_end_p (gsinext) ? NULL : gsi_stmt (gsinext);
|
|
|
|
/* Fold the main computation performed by the statement. */
|
|
switch (gimple_code (stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
{
|
|
unsigned old_num_ops = gimple_num_ops (stmt);
|
|
tree new_rhs = fold_gimple_assign (gsi);
|
|
tree lhs = gimple_assign_lhs (stmt);
|
|
if (new_rhs
|
|
&& !useless_type_conversion_p (TREE_TYPE (lhs),
|
|
TREE_TYPE (new_rhs)))
|
|
new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs);
|
|
if (new_rhs
|
|
&& (!inplace
|
|
|| get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops))
|
|
{
|
|
gimple_assign_set_rhs_from_tree (gsi, new_rhs);
|
|
changed = true;
|
|
}
|
|
break;
|
|
}
|
|
|
|
case GIMPLE_COND:
|
|
changed |= fold_gimple_cond (stmt);
|
|
break;
|
|
|
|
case GIMPLE_CALL:
|
|
/* Fold *& in call arguments. */
|
|
for (i = 0; i < gimple_call_num_args (stmt); ++i)
|
|
if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i)))
|
|
{
|
|
tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false);
|
|
if (tmp)
|
|
{
|
|
gimple_call_set_arg (stmt, i, tmp);
|
|
changed = true;
|
|
}
|
|
}
|
|
changed |= gimple_fold_call (gsi, inplace);
|
|
break;
|
|
|
|
case GIMPLE_ASM:
|
|
/* Fold *& in asm operands. */
|
|
for (i = 0; i < gimple_asm_noutputs (stmt); ++i)
|
|
{
|
|
tree link = gimple_asm_output_op (stmt, i);
|
|
tree op = TREE_VALUE (link);
|
|
if (REFERENCE_CLASS_P (op)
|
|
&& (op = maybe_fold_reference (op, true)) != NULL_TREE)
|
|
{
|
|
TREE_VALUE (link) = op;
|
|
changed = true;
|
|
}
|
|
}
|
|
for (i = 0; i < gimple_asm_ninputs (stmt); ++i)
|
|
{
|
|
tree link = gimple_asm_input_op (stmt, i);
|
|
tree op = TREE_VALUE (link);
|
|
if (REFERENCE_CLASS_P (op)
|
|
&& (op = maybe_fold_reference (op, false)) != NULL_TREE)
|
|
{
|
|
TREE_VALUE (link) = op;
|
|
changed = true;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case GIMPLE_DEBUG:
|
|
if (gimple_debug_bind_p (stmt))
|
|
{
|
|
tree val = gimple_debug_bind_get_value (stmt);
|
|
if (val
|
|
&& REFERENCE_CLASS_P (val))
|
|
{
|
|
tree tem = maybe_fold_reference (val, false);
|
|
if (tem)
|
|
{
|
|
gimple_debug_bind_set_value (stmt, tem);
|
|
changed = true;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:;
|
|
}
|
|
|
|
/* If stmt folds into nothing and it was the last stmt in a bb,
|
|
don't call gsi_stmt. */
|
|
if (gsi_end_p (*gsi))
|
|
{
|
|
gcc_assert (next_stmt == NULL);
|
|
return changed;
|
|
}
|
|
|
|
stmt = gsi_stmt (*gsi);
|
|
|
|
/* Fold *& on the lhs. Don't do this if stmt folded into nothing,
|
|
as we'd changing the next stmt. */
|
|
if (gimple_has_lhs (stmt) && stmt != next_stmt)
|
|
{
|
|
tree lhs = gimple_get_lhs (stmt);
|
|
if (lhs && REFERENCE_CLASS_P (lhs))
|
|
{
|
|
tree new_lhs = maybe_fold_reference (lhs, true);
|
|
if (new_lhs)
|
|
{
|
|
gimple_set_lhs (stmt, new_lhs);
|
|
changed = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
return changed;
|
|
}
|
|
|
|
/* Fold the statement pointed to by GSI. In some cases, this function may
|
|
replace the whole statement with a new one. Returns true iff folding
|
|
makes any changes.
|
|
The statement pointed to by GSI should be in valid gimple form but may
|
|
be in unfolded state as resulting from for example constant propagation
|
|
which can produce *&x = 0. */
|
|
|
|
bool
|
|
fold_stmt (gimple_stmt_iterator *gsi)
|
|
{
|
|
return fold_stmt_1 (gsi, false);
|
|
}
|
|
|
|
/* Perform the minimal folding on statement STMT. Only operations like
|
|
*&x created by constant propagation are handled. The statement cannot
|
|
be replaced with a new one. Return true if the statement was
|
|
changed, false otherwise.
|
|
The statement STMT should be in valid gimple form but may
|
|
be in unfolded state as resulting from for example constant propagation
|
|
which can produce *&x = 0. */
|
|
|
|
bool
|
|
fold_stmt_inplace (gimple stmt)
|
|
{
|
|
gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
|
|
bool changed = fold_stmt_1 (&gsi, true);
|
|
gcc_assert (gsi_stmt (gsi) == stmt);
|
|
return changed;
|
|
}
|
|
|
|
/* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE
|
|
if EXPR is null or we don't know how.
|
|
If non-null, the result always has boolean type. */
|
|
|
|
static tree
|
|
canonicalize_bool (tree expr, bool invert)
|
|
{
|
|
if (!expr)
|
|
return NULL_TREE;
|
|
else if (invert)
|
|
{
|
|
if (integer_nonzerop (expr))
|
|
return boolean_false_node;
|
|
else if (integer_zerop (expr))
|
|
return boolean_true_node;
|
|
else if (TREE_CODE (expr) == SSA_NAME)
|
|
return fold_build2 (EQ_EXPR, boolean_type_node, expr,
|
|
build_int_cst (TREE_TYPE (expr), 0));
|
|
else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison)
|
|
return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false),
|
|
boolean_type_node,
|
|
TREE_OPERAND (expr, 0),
|
|
TREE_OPERAND (expr, 1));
|
|
else
|
|
return NULL_TREE;
|
|
}
|
|
else
|
|
{
|
|
if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE)
|
|
return expr;
|
|
if (integer_nonzerop (expr))
|
|
return boolean_true_node;
|
|
else if (integer_zerop (expr))
|
|
return boolean_false_node;
|
|
else if (TREE_CODE (expr) == SSA_NAME)
|
|
return fold_build2 (NE_EXPR, boolean_type_node, expr,
|
|
build_int_cst (TREE_TYPE (expr), 0));
|
|
else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison)
|
|
return fold_build2 (TREE_CODE (expr),
|
|
boolean_type_node,
|
|
TREE_OPERAND (expr, 0),
|
|
TREE_OPERAND (expr, 1));
|
|
else
|
|
return NULL_TREE;
|
|
}
|
|
}
|
|
|
|
/* Check to see if a boolean expression EXPR is logically equivalent to the
|
|
comparison (OP1 CODE OP2). Check for various identities involving
|
|
SSA_NAMEs. */
|
|
|
|
static bool
|
|
same_bool_comparison_p (const_tree expr, enum tree_code code,
|
|
const_tree op1, const_tree op2)
|
|
{
|
|
gimple s;
|
|
|
|
/* The obvious case. */
|
|
if (TREE_CODE (expr) == code
|
|
&& operand_equal_p (TREE_OPERAND (expr, 0), op1, 0)
|
|
&& operand_equal_p (TREE_OPERAND (expr, 1), op2, 0))
|
|
return true;
|
|
|
|
/* Check for comparing (name, name != 0) and the case where expr
|
|
is an SSA_NAME with a definition matching the comparison. */
|
|
if (TREE_CODE (expr) == SSA_NAME
|
|
&& TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE)
|
|
{
|
|
if (operand_equal_p (expr, op1, 0))
|
|
return ((code == NE_EXPR && integer_zerop (op2))
|
|
|| (code == EQ_EXPR && integer_nonzerop (op2)));
|
|
s = SSA_NAME_DEF_STMT (expr);
|
|
if (is_gimple_assign (s)
|
|
&& gimple_assign_rhs_code (s) == code
|
|
&& operand_equal_p (gimple_assign_rhs1 (s), op1, 0)
|
|
&& operand_equal_p (gimple_assign_rhs2 (s), op2, 0))
|
|
return true;
|
|
}
|
|
|
|
/* If op1 is of the form (name != 0) or (name == 0), and the definition
|
|
of name is a comparison, recurse. */
|
|
if (TREE_CODE (op1) == SSA_NAME
|
|
&& TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE)
|
|
{
|
|
s = SSA_NAME_DEF_STMT (op1);
|
|
if (is_gimple_assign (s)
|
|
&& TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison)
|
|
{
|
|
enum tree_code c = gimple_assign_rhs_code (s);
|
|
if ((c == NE_EXPR && integer_zerop (op2))
|
|
|| (c == EQ_EXPR && integer_nonzerop (op2)))
|
|
return same_bool_comparison_p (expr, c,
|
|
gimple_assign_rhs1 (s),
|
|
gimple_assign_rhs2 (s));
|
|
if ((c == EQ_EXPR && integer_zerop (op2))
|
|
|| (c == NE_EXPR && integer_nonzerop (op2)))
|
|
return same_bool_comparison_p (expr,
|
|
invert_tree_comparison (c, false),
|
|
gimple_assign_rhs1 (s),
|
|
gimple_assign_rhs2 (s));
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Check to see if two boolean expressions OP1 and OP2 are logically
|
|
equivalent. */
|
|
|
|
static bool
|
|
same_bool_result_p (const_tree op1, const_tree op2)
|
|
{
|
|
/* Simple cases first. */
|
|
if (operand_equal_p (op1, op2, 0))
|
|
return true;
|
|
|
|
/* Check the cases where at least one of the operands is a comparison.
|
|
These are a bit smarter than operand_equal_p in that they apply some
|
|
identifies on SSA_NAMEs. */
|
|
if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison
|
|
&& same_bool_comparison_p (op1, TREE_CODE (op2),
|
|
TREE_OPERAND (op2, 0),
|
|
TREE_OPERAND (op2, 1)))
|
|
return true;
|
|
if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison
|
|
&& same_bool_comparison_p (op2, TREE_CODE (op1),
|
|
TREE_OPERAND (op1, 0),
|
|
TREE_OPERAND (op1, 1)))
|
|
return true;
|
|
|
|
/* Default case. */
|
|
return false;
|
|
}
|
|
|
|
/* Forward declarations for some mutually recursive functions. */
|
|
|
|
static tree
|
|
and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
|
|
enum tree_code code2, tree op2a, tree op2b);
|
|
static tree
|
|
and_var_with_comparison (tree var, bool invert,
|
|
enum tree_code code2, tree op2a, tree op2b);
|
|
static tree
|
|
and_var_with_comparison_1 (gimple stmt,
|
|
enum tree_code code2, tree op2a, tree op2b);
|
|
static tree
|
|
or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
|
|
enum tree_code code2, tree op2a, tree op2b);
|
|
static tree
|
|
or_var_with_comparison (tree var, bool invert,
|
|
enum tree_code code2, tree op2a, tree op2b);
|
|
static tree
|
|
or_var_with_comparison_1 (gimple stmt,
|
|
enum tree_code code2, tree op2a, tree op2b);
|
|
|
|
/* Helper function for and_comparisons_1: try to simplify the AND of the
|
|
ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B).
|
|
If INVERT is true, invert the value of the VAR before doing the AND.
|
|
Return NULL_EXPR if we can't simplify this to a single expression. */
|
|
|
|
static tree
|
|
and_var_with_comparison (tree var, bool invert,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
tree t;
|
|
gimple stmt = SSA_NAME_DEF_STMT (var);
|
|
|
|
/* We can only deal with variables whose definitions are assignments. */
|
|
if (!is_gimple_assign (stmt))
|
|
return NULL_TREE;
|
|
|
|
/* If we have an inverted comparison, apply DeMorgan's law and rewrite
|
|
!var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b))
|
|
Then we only have to consider the simpler non-inverted cases. */
|
|
if (invert)
|
|
t = or_var_with_comparison_1 (stmt,
|
|
invert_tree_comparison (code2, false),
|
|
op2a, op2b);
|
|
else
|
|
t = and_var_with_comparison_1 (stmt, code2, op2a, op2b);
|
|
return canonicalize_bool (t, invert);
|
|
}
|
|
|
|
/* Try to simplify the AND of the ssa variable defined by the assignment
|
|
STMT with the comparison specified by (OP2A CODE2 OP2B).
|
|
Return NULL_EXPR if we can't simplify this to a single expression. */
|
|
|
|
static tree
|
|
and_var_with_comparison_1 (gimple stmt,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
tree var = gimple_assign_lhs (stmt);
|
|
tree true_test_var = NULL_TREE;
|
|
tree false_test_var = NULL_TREE;
|
|
enum tree_code innercode = gimple_assign_rhs_code (stmt);
|
|
|
|
/* Check for identities like (var AND (var == 0)) => false. */
|
|
if (TREE_CODE (op2a) == SSA_NAME
|
|
&& TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE)
|
|
{
|
|
if ((code2 == NE_EXPR && integer_zerop (op2b))
|
|
|| (code2 == EQ_EXPR && integer_nonzerop (op2b)))
|
|
{
|
|
true_test_var = op2a;
|
|
if (var == true_test_var)
|
|
return var;
|
|
}
|
|
else if ((code2 == EQ_EXPR && integer_zerop (op2b))
|
|
|| (code2 == NE_EXPR && integer_nonzerop (op2b)))
|
|
{
|
|
false_test_var = op2a;
|
|
if (var == false_test_var)
|
|
return boolean_false_node;
|
|
}
|
|
}
|
|
|
|
/* If the definition is a comparison, recurse on it. */
|
|
if (TREE_CODE_CLASS (innercode) == tcc_comparison)
|
|
{
|
|
tree t = and_comparisons_1 (innercode,
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt),
|
|
code2,
|
|
op2a,
|
|
op2b);
|
|
if (t)
|
|
return t;
|
|
}
|
|
|
|
/* If the definition is an AND or OR expression, we may be able to
|
|
simplify by reassociating. */
|
|
if (innercode == TRUTH_AND_EXPR
|
|
|| innercode == TRUTH_OR_EXPR
|
|
|| (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE
|
|
&& (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)))
|
|
{
|
|
tree inner1 = gimple_assign_rhs1 (stmt);
|
|
tree inner2 = gimple_assign_rhs2 (stmt);
|
|
gimple s;
|
|
tree t;
|
|
tree partial = NULL_TREE;
|
|
bool is_and = (innercode == TRUTH_AND_EXPR || innercode == BIT_AND_EXPR);
|
|
|
|
/* Check for boolean identities that don't require recursive examination
|
|
of inner1/inner2:
|
|
inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var
|
|
inner1 AND (inner1 OR inner2) => inner1
|
|
!inner1 AND (inner1 AND inner2) => false
|
|
!inner1 AND (inner1 OR inner2) => !inner1 AND inner2
|
|
Likewise for similar cases involving inner2. */
|
|
if (inner1 == true_test_var)
|
|
return (is_and ? var : inner1);
|
|
else if (inner2 == true_test_var)
|
|
return (is_and ? var : inner2);
|
|
else if (inner1 == false_test_var)
|
|
return (is_and
|
|
? boolean_false_node
|
|
: and_var_with_comparison (inner2, false, code2, op2a, op2b));
|
|
else if (inner2 == false_test_var)
|
|
return (is_and
|
|
? boolean_false_node
|
|
: and_var_with_comparison (inner1, false, code2, op2a, op2b));
|
|
|
|
/* Next, redistribute/reassociate the AND across the inner tests.
|
|
Compute the first partial result, (inner1 AND (op2a code op2b)) */
|
|
if (TREE_CODE (inner1) == SSA_NAME
|
|
&& is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1))
|
|
&& TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
|
|
&& (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s),
|
|
gimple_assign_rhs1 (s),
|
|
gimple_assign_rhs2 (s),
|
|
code2, op2a, op2b)))
|
|
{
|
|
/* Handle the AND case, where we are reassociating:
|
|
(inner1 AND inner2) AND (op2a code2 op2b)
|
|
=> (t AND inner2)
|
|
If the partial result t is a constant, we win. Otherwise
|
|
continue on to try reassociating with the other inner test. */
|
|
if (is_and)
|
|
{
|
|
if (integer_onep (t))
|
|
return inner2;
|
|
else if (integer_zerop (t))
|
|
return boolean_false_node;
|
|
}
|
|
|
|
/* Handle the OR case, where we are redistributing:
|
|
(inner1 OR inner2) AND (op2a code2 op2b)
|
|
=> (t OR (inner2 AND (op2a code2 op2b))) */
|
|
else if (integer_onep (t))
|
|
return boolean_true_node;
|
|
|
|
/* Save partial result for later. */
|
|
partial = t;
|
|
}
|
|
|
|
/* Compute the second partial result, (inner2 AND (op2a code op2b)) */
|
|
if (TREE_CODE (inner2) == SSA_NAME
|
|
&& is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2))
|
|
&& TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
|
|
&& (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s),
|
|
gimple_assign_rhs1 (s),
|
|
gimple_assign_rhs2 (s),
|
|
code2, op2a, op2b)))
|
|
{
|
|
/* Handle the AND case, where we are reassociating:
|
|
(inner1 AND inner2) AND (op2a code2 op2b)
|
|
=> (inner1 AND t) */
|
|
if (is_and)
|
|
{
|
|
if (integer_onep (t))
|
|
return inner1;
|
|
else if (integer_zerop (t))
|
|
return boolean_false_node;
|
|
/* If both are the same, we can apply the identity
|
|
(x AND x) == x. */
|
|
else if (partial && same_bool_result_p (t, partial))
|
|
return t;
|
|
}
|
|
|
|
/* Handle the OR case. where we are redistributing:
|
|
(inner1 OR inner2) AND (op2a code2 op2b)
|
|
=> (t OR (inner1 AND (op2a code2 op2b)))
|
|
=> (t OR partial) */
|
|
else
|
|
{
|
|
if (integer_onep (t))
|
|
return boolean_true_node;
|
|
else if (partial)
|
|
{
|
|
/* We already got a simplification for the other
|
|
operand to the redistributed OR expression. The
|
|
interesting case is when at least one is false.
|
|
Or, if both are the same, we can apply the identity
|
|
(x OR x) == x. */
|
|
if (integer_zerop (partial))
|
|
return t;
|
|
else if (integer_zerop (t))
|
|
return partial;
|
|
else if (same_bool_result_p (t, partial))
|
|
return t;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Try to simplify the AND of two comparisons defined by
|
|
(OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively.
|
|
If this can be done without constructing an intermediate value,
|
|
return the resulting tree; otherwise NULL_TREE is returned.
|
|
This function is deliberately asymmetric as it recurses on SSA_DEFs
|
|
in the first comparison but not the second. */
|
|
|
|
static tree
|
|
and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
/* First check for ((x CODE1 y) AND (x CODE2 y)). */
|
|
if (operand_equal_p (op1a, op2a, 0)
|
|
&& operand_equal_p (op1b, op2b, 0))
|
|
{
|
|
tree t = combine_comparisons (UNKNOWN_LOCATION,
|
|
TRUTH_ANDIF_EXPR, code1, code2,
|
|
boolean_type_node, op1a, op1b);
|
|
if (t)
|
|
return t;
|
|
}
|
|
|
|
/* Likewise the swapped case of the above. */
|
|
if (operand_equal_p (op1a, op2b, 0)
|
|
&& operand_equal_p (op1b, op2a, 0))
|
|
{
|
|
tree t = combine_comparisons (UNKNOWN_LOCATION,
|
|
TRUTH_ANDIF_EXPR, code1,
|
|
swap_tree_comparison (code2),
|
|
boolean_type_node, op1a, op1b);
|
|
if (t)
|
|
return t;
|
|
}
|
|
|
|
/* If both comparisons are of the same value against constants, we might
|
|
be able to merge them. */
|
|
if (operand_equal_p (op1a, op2a, 0)
|
|
&& TREE_CODE (op1b) == INTEGER_CST
|
|
&& TREE_CODE (op2b) == INTEGER_CST)
|
|
{
|
|
int cmp = tree_int_cst_compare (op1b, op2b);
|
|
|
|
/* If we have (op1a == op1b), we should either be able to
|
|
return that or FALSE, depending on whether the constant op1b
|
|
also satisfies the other comparison against op2b. */
|
|
if (code1 == EQ_EXPR)
|
|
{
|
|
bool done = true;
|
|
bool val;
|
|
switch (code2)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp < 0); break;
|
|
case GT_EXPR: val = (cmp > 0); break;
|
|
case LE_EXPR: val = (cmp <= 0); break;
|
|
case GE_EXPR: val = (cmp >= 0); break;
|
|
default: done = false;
|
|
}
|
|
if (done)
|
|
{
|
|
if (val)
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
else
|
|
return boolean_false_node;
|
|
}
|
|
}
|
|
/* Likewise if the second comparison is an == comparison. */
|
|
else if (code2 == EQ_EXPR)
|
|
{
|
|
bool done = true;
|
|
bool val;
|
|
switch (code1)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp > 0); break;
|
|
case GT_EXPR: val = (cmp < 0); break;
|
|
case LE_EXPR: val = (cmp >= 0); break;
|
|
case GE_EXPR: val = (cmp <= 0); break;
|
|
default: done = false;
|
|
}
|
|
if (done)
|
|
{
|
|
if (val)
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
else
|
|
return boolean_false_node;
|
|
}
|
|
}
|
|
|
|
/* Same business with inequality tests. */
|
|
else if (code1 == NE_EXPR)
|
|
{
|
|
bool val;
|
|
switch (code2)
|
|
{
|
|
case EQ_EXPR: val = (cmp != 0); break;
|
|
case NE_EXPR: val = (cmp == 0); break;
|
|
case LT_EXPR: val = (cmp >= 0); break;
|
|
case GT_EXPR: val = (cmp <= 0); break;
|
|
case LE_EXPR: val = (cmp > 0); break;
|
|
case GE_EXPR: val = (cmp < 0); break;
|
|
default:
|
|
val = false;
|
|
}
|
|
if (val)
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
}
|
|
else if (code2 == NE_EXPR)
|
|
{
|
|
bool val;
|
|
switch (code1)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp <= 0); break;
|
|
case GT_EXPR: val = (cmp >= 0); break;
|
|
case LE_EXPR: val = (cmp < 0); break;
|
|
case GE_EXPR: val = (cmp > 0); break;
|
|
default:
|
|
val = false;
|
|
}
|
|
if (val)
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
}
|
|
|
|
/* Chose the more restrictive of two < or <= comparisons. */
|
|
else if ((code1 == LT_EXPR || code1 == LE_EXPR)
|
|
&& (code2 == LT_EXPR || code2 == LE_EXPR))
|
|
{
|
|
if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR))
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
else
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
}
|
|
|
|
/* Likewise chose the more restrictive of two > or >= comparisons. */
|
|
else if ((code1 == GT_EXPR || code1 == GE_EXPR)
|
|
&& (code2 == GT_EXPR || code2 == GE_EXPR))
|
|
{
|
|
if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR))
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
else
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
}
|
|
|
|
/* Check for singleton ranges. */
|
|
else if (cmp == 0
|
|
&& ((code1 == LE_EXPR && code2 == GE_EXPR)
|
|
|| (code1 == GE_EXPR && code2 == LE_EXPR)))
|
|
return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b);
|
|
|
|
/* Check for disjoint ranges. */
|
|
else if (cmp <= 0
|
|
&& (code1 == LT_EXPR || code1 == LE_EXPR)
|
|
&& (code2 == GT_EXPR || code2 == GE_EXPR))
|
|
return boolean_false_node;
|
|
else if (cmp >= 0
|
|
&& (code1 == GT_EXPR || code1 == GE_EXPR)
|
|
&& (code2 == LT_EXPR || code2 == LE_EXPR))
|
|
return boolean_false_node;
|
|
}
|
|
|
|
/* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where
|
|
NAME's definition is a truth value. See if there are any simplifications
|
|
that can be done against the NAME's definition. */
|
|
if (TREE_CODE (op1a) == SSA_NAME
|
|
&& (code1 == NE_EXPR || code1 == EQ_EXPR)
|
|
&& (integer_zerop (op1b) || integer_onep (op1b)))
|
|
{
|
|
bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b))
|
|
|| (code1 == NE_EXPR && integer_onep (op1b)));
|
|
gimple stmt = SSA_NAME_DEF_STMT (op1a);
|
|
switch (gimple_code (stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
/* Try to simplify by copy-propagating the definition. */
|
|
return and_var_with_comparison (op1a, invert, code2, op2a, op2b);
|
|
|
|
case GIMPLE_PHI:
|
|
/* If every argument to the PHI produces the same result when
|
|
ANDed with the second comparison, we win.
|
|
Do not do this unless the type is bool since we need a bool
|
|
result here anyway. */
|
|
if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE)
|
|
{
|
|
tree result = NULL_TREE;
|
|
unsigned i;
|
|
for (i = 0; i < gimple_phi_num_args (stmt); i++)
|
|
{
|
|
tree arg = gimple_phi_arg_def (stmt, i);
|
|
|
|
/* If this PHI has itself as an argument, ignore it.
|
|
If all the other args produce the same result,
|
|
we're still OK. */
|
|
if (arg == gimple_phi_result (stmt))
|
|
continue;
|
|
else if (TREE_CODE (arg) == INTEGER_CST)
|
|
{
|
|
if (invert ? integer_nonzerop (arg) : integer_zerop (arg))
|
|
{
|
|
if (!result)
|
|
result = boolean_false_node;
|
|
else if (!integer_zerop (result))
|
|
return NULL_TREE;
|
|
}
|
|
else if (!result)
|
|
result = fold_build2 (code2, boolean_type_node,
|
|
op2a, op2b);
|
|
else if (!same_bool_comparison_p (result,
|
|
code2, op2a, op2b))
|
|
return NULL_TREE;
|
|
}
|
|
else if (TREE_CODE (arg) == SSA_NAME
|
|
&& !SSA_NAME_IS_DEFAULT_DEF (arg))
|
|
{
|
|
tree temp;
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (arg);
|
|
/* In simple cases we can look through PHI nodes,
|
|
but we have to be careful with loops.
|
|
See PR49073. */
|
|
if (! dom_info_available_p (CDI_DOMINATORS)
|
|
|| gimple_bb (def_stmt) == gimple_bb (stmt)
|
|
|| dominated_by_p (CDI_DOMINATORS,
|
|
gimple_bb (def_stmt),
|
|
gimple_bb (stmt)))
|
|
return NULL_TREE;
|
|
temp = and_var_with_comparison (arg, invert, code2,
|
|
op2a, op2b);
|
|
if (!temp)
|
|
return NULL_TREE;
|
|
else if (!result)
|
|
result = temp;
|
|
else if (!same_bool_result_p (result, temp))
|
|
return NULL_TREE;
|
|
}
|
|
else
|
|
return NULL_TREE;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Try to simplify the AND of two comparisons, specified by
|
|
(OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively.
|
|
If this can be simplified to a single expression (without requiring
|
|
introducing more SSA variables to hold intermediate values),
|
|
return the resulting tree. Otherwise return NULL_TREE.
|
|
If the result expression is non-null, it has boolean type. */
|
|
|
|
tree
|
|
maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b);
|
|
if (t)
|
|
return t;
|
|
else
|
|
return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b);
|
|
}
|
|
|
|
/* Helper function for or_comparisons_1: try to simplify the OR of the
|
|
ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B).
|
|
If INVERT is true, invert the value of VAR before doing the OR.
|
|
Return NULL_EXPR if we can't simplify this to a single expression. */
|
|
|
|
static tree
|
|
or_var_with_comparison (tree var, bool invert,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
tree t;
|
|
gimple stmt = SSA_NAME_DEF_STMT (var);
|
|
|
|
/* We can only deal with variables whose definitions are assignments. */
|
|
if (!is_gimple_assign (stmt))
|
|
return NULL_TREE;
|
|
|
|
/* If we have an inverted comparison, apply DeMorgan's law and rewrite
|
|
!var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b))
|
|
Then we only have to consider the simpler non-inverted cases. */
|
|
if (invert)
|
|
t = and_var_with_comparison_1 (stmt,
|
|
invert_tree_comparison (code2, false),
|
|
op2a, op2b);
|
|
else
|
|
t = or_var_with_comparison_1 (stmt, code2, op2a, op2b);
|
|
return canonicalize_bool (t, invert);
|
|
}
|
|
|
|
/* Try to simplify the OR of the ssa variable defined by the assignment
|
|
STMT with the comparison specified by (OP2A CODE2 OP2B).
|
|
Return NULL_EXPR if we can't simplify this to a single expression. */
|
|
|
|
static tree
|
|
or_var_with_comparison_1 (gimple stmt,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
tree var = gimple_assign_lhs (stmt);
|
|
tree true_test_var = NULL_TREE;
|
|
tree false_test_var = NULL_TREE;
|
|
enum tree_code innercode = gimple_assign_rhs_code (stmt);
|
|
|
|
/* Check for identities like (var OR (var != 0)) => true . */
|
|
if (TREE_CODE (op2a) == SSA_NAME
|
|
&& TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE)
|
|
{
|
|
if ((code2 == NE_EXPR && integer_zerop (op2b))
|
|
|| (code2 == EQ_EXPR && integer_nonzerop (op2b)))
|
|
{
|
|
true_test_var = op2a;
|
|
if (var == true_test_var)
|
|
return var;
|
|
}
|
|
else if ((code2 == EQ_EXPR && integer_zerop (op2b))
|
|
|| (code2 == NE_EXPR && integer_nonzerop (op2b)))
|
|
{
|
|
false_test_var = op2a;
|
|
if (var == false_test_var)
|
|
return boolean_true_node;
|
|
}
|
|
}
|
|
|
|
/* If the definition is a comparison, recurse on it. */
|
|
if (TREE_CODE_CLASS (innercode) == tcc_comparison)
|
|
{
|
|
tree t = or_comparisons_1 (innercode,
|
|
gimple_assign_rhs1 (stmt),
|
|
gimple_assign_rhs2 (stmt),
|
|
code2,
|
|
op2a,
|
|
op2b);
|
|
if (t)
|
|
return t;
|
|
}
|
|
|
|
/* If the definition is an AND or OR expression, we may be able to
|
|
simplify by reassociating. */
|
|
if (innercode == TRUTH_AND_EXPR
|
|
|| innercode == TRUTH_OR_EXPR
|
|
|| (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE
|
|
&& (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)))
|
|
{
|
|
tree inner1 = gimple_assign_rhs1 (stmt);
|
|
tree inner2 = gimple_assign_rhs2 (stmt);
|
|
gimple s;
|
|
tree t;
|
|
tree partial = NULL_TREE;
|
|
bool is_or = (innercode == TRUTH_OR_EXPR || innercode == BIT_IOR_EXPR);
|
|
|
|
/* Check for boolean identities that don't require recursive examination
|
|
of inner1/inner2:
|
|
inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var
|
|
inner1 OR (inner1 AND inner2) => inner1
|
|
!inner1 OR (inner1 OR inner2) => true
|
|
!inner1 OR (inner1 AND inner2) => !inner1 OR inner2
|
|
*/
|
|
if (inner1 == true_test_var)
|
|
return (is_or ? var : inner1);
|
|
else if (inner2 == true_test_var)
|
|
return (is_or ? var : inner2);
|
|
else if (inner1 == false_test_var)
|
|
return (is_or
|
|
? boolean_true_node
|
|
: or_var_with_comparison (inner2, false, code2, op2a, op2b));
|
|
else if (inner2 == false_test_var)
|
|
return (is_or
|
|
? boolean_true_node
|
|
: or_var_with_comparison (inner1, false, code2, op2a, op2b));
|
|
|
|
/* Next, redistribute/reassociate the OR across the inner tests.
|
|
Compute the first partial result, (inner1 OR (op2a code op2b)) */
|
|
if (TREE_CODE (inner1) == SSA_NAME
|
|
&& is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1))
|
|
&& TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
|
|
&& (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s),
|
|
gimple_assign_rhs1 (s),
|
|
gimple_assign_rhs2 (s),
|
|
code2, op2a, op2b)))
|
|
{
|
|
/* Handle the OR case, where we are reassociating:
|
|
(inner1 OR inner2) OR (op2a code2 op2b)
|
|
=> (t OR inner2)
|
|
If the partial result t is a constant, we win. Otherwise
|
|
continue on to try reassociating with the other inner test. */
|
|
if (is_or)
|
|
{
|
|
if (integer_onep (t))
|
|
return boolean_true_node;
|
|
else if (integer_zerop (t))
|
|
return inner2;
|
|
}
|
|
|
|
/* Handle the AND case, where we are redistributing:
|
|
(inner1 AND inner2) OR (op2a code2 op2b)
|
|
=> (t AND (inner2 OR (op2a code op2b))) */
|
|
else if (integer_zerop (t))
|
|
return boolean_false_node;
|
|
|
|
/* Save partial result for later. */
|
|
partial = t;
|
|
}
|
|
|
|
/* Compute the second partial result, (inner2 OR (op2a code op2b)) */
|
|
if (TREE_CODE (inner2) == SSA_NAME
|
|
&& is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2))
|
|
&& TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison
|
|
&& (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s),
|
|
gimple_assign_rhs1 (s),
|
|
gimple_assign_rhs2 (s),
|
|
code2, op2a, op2b)))
|
|
{
|
|
/* Handle the OR case, where we are reassociating:
|
|
(inner1 OR inner2) OR (op2a code2 op2b)
|
|
=> (inner1 OR t)
|
|
=> (t OR partial) */
|
|
if (is_or)
|
|
{
|
|
if (integer_zerop (t))
|
|
return inner1;
|
|
else if (integer_onep (t))
|
|
return boolean_true_node;
|
|
/* If both are the same, we can apply the identity
|
|
(x OR x) == x. */
|
|
else if (partial && same_bool_result_p (t, partial))
|
|
return t;
|
|
}
|
|
|
|
/* Handle the AND case, where we are redistributing:
|
|
(inner1 AND inner2) OR (op2a code2 op2b)
|
|
=> (t AND (inner1 OR (op2a code2 op2b)))
|
|
=> (t AND partial) */
|
|
else
|
|
{
|
|
if (integer_zerop (t))
|
|
return boolean_false_node;
|
|
else if (partial)
|
|
{
|
|
/* We already got a simplification for the other
|
|
operand to the redistributed AND expression. The
|
|
interesting case is when at least one is true.
|
|
Or, if both are the same, we can apply the identity
|
|
(x AND x) == x. */
|
|
if (integer_onep (partial))
|
|
return t;
|
|
else if (integer_onep (t))
|
|
return partial;
|
|
else if (same_bool_result_p (t, partial))
|
|
return t;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Try to simplify the OR of two comparisons defined by
|
|
(OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively.
|
|
If this can be done without constructing an intermediate value,
|
|
return the resulting tree; otherwise NULL_TREE is returned.
|
|
This function is deliberately asymmetric as it recurses on SSA_DEFs
|
|
in the first comparison but not the second. */
|
|
|
|
static tree
|
|
or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
/* First check for ((x CODE1 y) OR (x CODE2 y)). */
|
|
if (operand_equal_p (op1a, op2a, 0)
|
|
&& operand_equal_p (op1b, op2b, 0))
|
|
{
|
|
tree t = combine_comparisons (UNKNOWN_LOCATION,
|
|
TRUTH_ORIF_EXPR, code1, code2,
|
|
boolean_type_node, op1a, op1b);
|
|
if (t)
|
|
return t;
|
|
}
|
|
|
|
/* Likewise the swapped case of the above. */
|
|
if (operand_equal_p (op1a, op2b, 0)
|
|
&& operand_equal_p (op1b, op2a, 0))
|
|
{
|
|
tree t = combine_comparisons (UNKNOWN_LOCATION,
|
|
TRUTH_ORIF_EXPR, code1,
|
|
swap_tree_comparison (code2),
|
|
boolean_type_node, op1a, op1b);
|
|
if (t)
|
|
return t;
|
|
}
|
|
|
|
/* If both comparisons are of the same value against constants, we might
|
|
be able to merge them. */
|
|
if (operand_equal_p (op1a, op2a, 0)
|
|
&& TREE_CODE (op1b) == INTEGER_CST
|
|
&& TREE_CODE (op2b) == INTEGER_CST)
|
|
{
|
|
int cmp = tree_int_cst_compare (op1b, op2b);
|
|
|
|
/* If we have (op1a != op1b), we should either be able to
|
|
return that or TRUE, depending on whether the constant op1b
|
|
also satisfies the other comparison against op2b. */
|
|
if (code1 == NE_EXPR)
|
|
{
|
|
bool done = true;
|
|
bool val;
|
|
switch (code2)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp < 0); break;
|
|
case GT_EXPR: val = (cmp > 0); break;
|
|
case LE_EXPR: val = (cmp <= 0); break;
|
|
case GE_EXPR: val = (cmp >= 0); break;
|
|
default: done = false;
|
|
}
|
|
if (done)
|
|
{
|
|
if (val)
|
|
return boolean_true_node;
|
|
else
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
}
|
|
}
|
|
/* Likewise if the second comparison is a != comparison. */
|
|
else if (code2 == NE_EXPR)
|
|
{
|
|
bool done = true;
|
|
bool val;
|
|
switch (code1)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp > 0); break;
|
|
case GT_EXPR: val = (cmp < 0); break;
|
|
case LE_EXPR: val = (cmp >= 0); break;
|
|
case GE_EXPR: val = (cmp <= 0); break;
|
|
default: done = false;
|
|
}
|
|
if (done)
|
|
{
|
|
if (val)
|
|
return boolean_true_node;
|
|
else
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
}
|
|
}
|
|
|
|
/* See if an equality test is redundant with the other comparison. */
|
|
else if (code1 == EQ_EXPR)
|
|
{
|
|
bool val;
|
|
switch (code2)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp < 0); break;
|
|
case GT_EXPR: val = (cmp > 0); break;
|
|
case LE_EXPR: val = (cmp <= 0); break;
|
|
case GE_EXPR: val = (cmp >= 0); break;
|
|
default:
|
|
val = false;
|
|
}
|
|
if (val)
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
}
|
|
else if (code2 == EQ_EXPR)
|
|
{
|
|
bool val;
|
|
switch (code1)
|
|
{
|
|
case EQ_EXPR: val = (cmp == 0); break;
|
|
case NE_EXPR: val = (cmp != 0); break;
|
|
case LT_EXPR: val = (cmp > 0); break;
|
|
case GT_EXPR: val = (cmp < 0); break;
|
|
case LE_EXPR: val = (cmp >= 0); break;
|
|
case GE_EXPR: val = (cmp <= 0); break;
|
|
default:
|
|
val = false;
|
|
}
|
|
if (val)
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
}
|
|
|
|
/* Chose the less restrictive of two < or <= comparisons. */
|
|
else if ((code1 == LT_EXPR || code1 == LE_EXPR)
|
|
&& (code2 == LT_EXPR || code2 == LE_EXPR))
|
|
{
|
|
if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR))
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
else
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
}
|
|
|
|
/* Likewise chose the less restrictive of two > or >= comparisons. */
|
|
else if ((code1 == GT_EXPR || code1 == GE_EXPR)
|
|
&& (code2 == GT_EXPR || code2 == GE_EXPR))
|
|
{
|
|
if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR))
|
|
return fold_build2 (code2, boolean_type_node, op2a, op2b);
|
|
else
|
|
return fold_build2 (code1, boolean_type_node, op1a, op1b);
|
|
}
|
|
|
|
/* Check for singleton ranges. */
|
|
else if (cmp == 0
|
|
&& ((code1 == LT_EXPR && code2 == GT_EXPR)
|
|
|| (code1 == GT_EXPR && code2 == LT_EXPR)))
|
|
return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b);
|
|
|
|
/* Check for less/greater pairs that don't restrict the range at all. */
|
|
else if (cmp >= 0
|
|
&& (code1 == LT_EXPR || code1 == LE_EXPR)
|
|
&& (code2 == GT_EXPR || code2 == GE_EXPR))
|
|
return boolean_true_node;
|
|
else if (cmp <= 0
|
|
&& (code1 == GT_EXPR || code1 == GE_EXPR)
|
|
&& (code2 == LT_EXPR || code2 == LE_EXPR))
|
|
return boolean_true_node;
|
|
}
|
|
|
|
/* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where
|
|
NAME's definition is a truth value. See if there are any simplifications
|
|
that can be done against the NAME's definition. */
|
|
if (TREE_CODE (op1a) == SSA_NAME
|
|
&& (code1 == NE_EXPR || code1 == EQ_EXPR)
|
|
&& (integer_zerop (op1b) || integer_onep (op1b)))
|
|
{
|
|
bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b))
|
|
|| (code1 == NE_EXPR && integer_onep (op1b)));
|
|
gimple stmt = SSA_NAME_DEF_STMT (op1a);
|
|
switch (gimple_code (stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
/* Try to simplify by copy-propagating the definition. */
|
|
return or_var_with_comparison (op1a, invert, code2, op2a, op2b);
|
|
|
|
case GIMPLE_PHI:
|
|
/* If every argument to the PHI produces the same result when
|
|
ORed with the second comparison, we win.
|
|
Do not do this unless the type is bool since we need a bool
|
|
result here anyway. */
|
|
if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE)
|
|
{
|
|
tree result = NULL_TREE;
|
|
unsigned i;
|
|
for (i = 0; i < gimple_phi_num_args (stmt); i++)
|
|
{
|
|
tree arg = gimple_phi_arg_def (stmt, i);
|
|
|
|
/* If this PHI has itself as an argument, ignore it.
|
|
If all the other args produce the same result,
|
|
we're still OK. */
|
|
if (arg == gimple_phi_result (stmt))
|
|
continue;
|
|
else if (TREE_CODE (arg) == INTEGER_CST)
|
|
{
|
|
if (invert ? integer_zerop (arg) : integer_nonzerop (arg))
|
|
{
|
|
if (!result)
|
|
result = boolean_true_node;
|
|
else if (!integer_onep (result))
|
|
return NULL_TREE;
|
|
}
|
|
else if (!result)
|
|
result = fold_build2 (code2, boolean_type_node,
|
|
op2a, op2b);
|
|
else if (!same_bool_comparison_p (result,
|
|
code2, op2a, op2b))
|
|
return NULL_TREE;
|
|
}
|
|
else if (TREE_CODE (arg) == SSA_NAME
|
|
&& !SSA_NAME_IS_DEFAULT_DEF (arg))
|
|
{
|
|
tree temp;
|
|
gimple def_stmt = SSA_NAME_DEF_STMT (arg);
|
|
/* In simple cases we can look through PHI nodes,
|
|
but we have to be careful with loops.
|
|
See PR49073. */
|
|
if (! dom_info_available_p (CDI_DOMINATORS)
|
|
|| gimple_bb (def_stmt) == gimple_bb (stmt)
|
|
|| dominated_by_p (CDI_DOMINATORS,
|
|
gimple_bb (def_stmt),
|
|
gimple_bb (stmt)))
|
|
return NULL_TREE;
|
|
temp = or_var_with_comparison (arg, invert, code2,
|
|
op2a, op2b);
|
|
if (!temp)
|
|
return NULL_TREE;
|
|
else if (!result)
|
|
result = temp;
|
|
else if (!same_bool_result_p (result, temp))
|
|
return NULL_TREE;
|
|
}
|
|
else
|
|
return NULL_TREE;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Try to simplify the OR of two comparisons, specified by
|
|
(OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively.
|
|
If this can be simplified to a single expression (without requiring
|
|
introducing more SSA variables to hold intermediate values),
|
|
return the resulting tree. Otherwise return NULL_TREE.
|
|
If the result expression is non-null, it has boolean type. */
|
|
|
|
tree
|
|
maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b,
|
|
enum tree_code code2, tree op2a, tree op2b)
|
|
{
|
|
tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b);
|
|
if (t)
|
|
return t;
|
|
else
|
|
return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b);
|
|
}
|
|
|
|
|
|
/* Fold STMT to a constant using VALUEIZE to valueize SSA names.
|
|
|
|
Either NULL_TREE, a simplified but non-constant or a constant
|
|
is returned.
|
|
|
|
??? This should go into a gimple-fold-inline.h file to be eventually
|
|
privatized with the single valueize function used in the various TUs
|
|
to avoid the indirect function call overhead. */
|
|
|
|
tree
|
|
gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree))
|
|
{
|
|
location_t loc = gimple_location (stmt);
|
|
switch (gimple_code (stmt))
|
|
{
|
|
case GIMPLE_ASSIGN:
|
|
{
|
|
enum tree_code subcode = gimple_assign_rhs_code (stmt);
|
|
|
|
switch (get_gimple_rhs_class (subcode))
|
|
{
|
|
case GIMPLE_SINGLE_RHS:
|
|
{
|
|
tree rhs = gimple_assign_rhs1 (stmt);
|
|
enum tree_code_class kind = TREE_CODE_CLASS (subcode);
|
|
|
|
if (TREE_CODE (rhs) == SSA_NAME)
|
|
{
|
|
/* If the RHS is an SSA_NAME, return its known constant value,
|
|
if any. */
|
|
return (*valueize) (rhs);
|
|
}
|
|
/* Handle propagating invariant addresses into address
|
|
operations. */
|
|
else if (TREE_CODE (rhs) == ADDR_EXPR
|
|
&& !is_gimple_min_invariant (rhs))
|
|
{
|
|
HOST_WIDE_INT offset;
|
|
tree base;
|
|
base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0),
|
|
&offset,
|
|
valueize);
|
|
if (base
|
|
&& (CONSTANT_CLASS_P (base)
|
|
|| decl_address_invariant_p (base)))
|
|
return build_invariant_address (TREE_TYPE (rhs),
|
|
base, offset);
|
|
}
|
|
else if (TREE_CODE (rhs) == CONSTRUCTOR
|
|
&& TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE
|
|
&& (CONSTRUCTOR_NELTS (rhs)
|
|
== TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))))
|
|
{
|
|
unsigned i;
|
|
tree val, list;
|
|
|
|
list = NULL_TREE;
|
|
FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val)
|
|
{
|
|
val = (*valueize) (val);
|
|
if (TREE_CODE (val) == INTEGER_CST
|
|
|| TREE_CODE (val) == REAL_CST
|
|
|| TREE_CODE (val) == FIXED_CST)
|
|
list = tree_cons (NULL_TREE, val, list);
|
|
else
|
|
return NULL_TREE;
|
|
}
|
|
|
|
return build_vector (TREE_TYPE (rhs), nreverse (list));
|
|
}
|
|
|
|
if (kind == tcc_reference)
|
|
{
|
|
if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR
|
|
|| TREE_CODE (rhs) == REALPART_EXPR
|
|
|| TREE_CODE (rhs) == IMAGPART_EXPR)
|
|
&& TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
|
|
{
|
|
tree val = (*valueize) (TREE_OPERAND (rhs, 0));
|
|
return fold_unary_loc (EXPR_LOCATION (rhs),
|
|
TREE_CODE (rhs),
|
|
TREE_TYPE (rhs), val);
|
|
}
|
|
else if (TREE_CODE (rhs) == BIT_FIELD_REF
|
|
&& TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
|
|
{
|
|
tree val = (*valueize) (TREE_OPERAND (rhs, 0));
|
|
return fold_ternary_loc (EXPR_LOCATION (rhs),
|
|
TREE_CODE (rhs),
|
|
TREE_TYPE (rhs), val,
|
|
TREE_OPERAND (rhs, 1),
|
|
TREE_OPERAND (rhs, 2));
|
|
}
|
|
else if (TREE_CODE (rhs) == MEM_REF
|
|
&& TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
|
|
{
|
|
tree val = (*valueize) (TREE_OPERAND (rhs, 0));
|
|
if (TREE_CODE (val) == ADDR_EXPR
|
|
&& is_gimple_min_invariant (val))
|
|
{
|
|
tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs),
|
|
unshare_expr (val),
|
|
TREE_OPERAND (rhs, 1));
|
|
if (tem)
|
|
rhs = tem;
|
|
}
|
|
}
|
|
return fold_const_aggregate_ref_1 (rhs, valueize);
|
|
}
|
|
else if (kind == tcc_declaration)
|
|
return get_symbol_constant_value (rhs);
|
|
return rhs;
|
|
}
|
|
|
|
case GIMPLE_UNARY_RHS:
|
|
{
|
|
/* Handle unary operators that can appear in GIMPLE form.
|
|
Note that we know the single operand must be a constant,
|
|
so this should almost always return a simplified RHS. */
|
|
tree lhs = gimple_assign_lhs (stmt);
|
|
tree op0 = (*valueize) (gimple_assign_rhs1 (stmt));
|
|
|
|
/* Conversions are useless for CCP purposes if they are
|
|
value-preserving. Thus the restrictions that
|
|
useless_type_conversion_p places for pointer type conversions
|
|
do not apply here. Substitution later will only substitute to
|
|
allowed places. */
|
|
if (CONVERT_EXPR_CODE_P (subcode)
|
|
&& POINTER_TYPE_P (TREE_TYPE (lhs))
|
|
&& POINTER_TYPE_P (TREE_TYPE (op0)))
|
|
{
|
|
tree tem;
|
|
/* Try to re-construct array references on-the-fly. */
|
|
if (!useless_type_conversion_p (TREE_TYPE (lhs),
|
|
TREE_TYPE (op0))
|
|
&& ((tem = maybe_fold_offset_to_address
|
|
(loc,
|
|
op0, integer_zero_node, TREE_TYPE (lhs)))
|
|
!= NULL_TREE))
|
|
return tem;
|
|
return op0;
|
|
}
|
|
|
|
return
|
|
fold_unary_ignore_overflow_loc (loc, subcode,
|
|
gimple_expr_type (stmt), op0);
|
|
}
|
|
|
|
case GIMPLE_BINARY_RHS:
|
|
{
|
|
/* Handle binary operators that can appear in GIMPLE form. */
|
|
tree op0 = (*valueize) (gimple_assign_rhs1 (stmt));
|
|
tree op1 = (*valueize) (gimple_assign_rhs2 (stmt));
|
|
|
|
/* Translate &x + CST into an invariant form suitable for
|
|
further propagation. */
|
|
if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
|
|
&& TREE_CODE (op0) == ADDR_EXPR
|
|
&& TREE_CODE (op1) == INTEGER_CST)
|
|
{
|
|
tree off = fold_convert (ptr_type_node, op1);
|
|
return build_fold_addr_expr
|
|
(fold_build2 (MEM_REF,
|
|
TREE_TYPE (TREE_TYPE (op0)),
|
|
unshare_expr (op0), off));
|
|
}
|
|
|
|
return fold_binary_loc (loc, subcode,
|
|
gimple_expr_type (stmt), op0, op1);
|
|
}
|
|
|
|
case GIMPLE_TERNARY_RHS:
|
|
{
|
|
/* Handle ternary operators that can appear in GIMPLE form. */
|
|
tree op0 = (*valueize) (gimple_assign_rhs1 (stmt));
|
|
tree op1 = (*valueize) (gimple_assign_rhs2 (stmt));
|
|
tree op2 = (*valueize) (gimple_assign_rhs3 (stmt));
|
|
|
|
return fold_ternary_loc (loc, subcode,
|
|
gimple_expr_type (stmt), op0, op1, op2);
|
|
}
|
|
|
|
default:
|
|
gcc_unreachable ();
|
|
}
|
|
}
|
|
|
|
case GIMPLE_CALL:
|
|
{
|
|
tree fn;
|
|
|
|
if (gimple_call_internal_p (stmt))
|
|
/* No folding yet for these functions. */
|
|
return NULL_TREE;
|
|
|
|
fn = (*valueize) (gimple_call_fn (stmt));
|
|
if (TREE_CODE (fn) == ADDR_EXPR
|
|
&& TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL
|
|
&& DECL_BUILT_IN (TREE_OPERAND (fn, 0)))
|
|
{
|
|
tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt));
|
|
tree call, retval;
|
|
unsigned i;
|
|
for (i = 0; i < gimple_call_num_args (stmt); ++i)
|
|
args[i] = (*valueize) (gimple_call_arg (stmt, i));
|
|
call = build_call_array_loc (loc,
|
|
gimple_call_return_type (stmt),
|
|
fn, gimple_call_num_args (stmt), args);
|
|
retval = fold_call_expr (EXPR_LOCATION (call), call, false);
|
|
if (retval)
|
|
/* fold_call_expr wraps the result inside a NOP_EXPR. */
|
|
STRIP_NOPS (retval);
|
|
return retval;
|
|
}
|
|
return NULL_TREE;
|
|
}
|
|
|
|
default:
|
|
return NULL_TREE;
|
|
}
|
|
}
|
|
|
|
/* Fold STMT to a constant using VALUEIZE to valueize SSA names.
|
|
Returns NULL_TREE if folding to a constant is not possible, otherwise
|
|
returns a constant according to is_gimple_min_invariant. */
|
|
|
|
tree
|
|
gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree))
|
|
{
|
|
tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize);
|
|
if (res && is_gimple_min_invariant (res))
|
|
return res;
|
|
return NULL_TREE;
|
|
}
|
|
|
|
|
|
/* The following set of functions are supposed to fold references using
|
|
their constant initializers. */
|
|
|
|
static tree fold_ctor_reference (tree type, tree ctor,
|
|
unsigned HOST_WIDE_INT offset,
|
|
unsigned HOST_WIDE_INT size);
|
|
|
|
/* See if we can find constructor defining value of BASE.
|
|
When we know the consructor with constant offset (such as
|
|
base is array[40] and we do know constructor of array), then
|
|
BIT_OFFSET is adjusted accordingly.
|
|
|
|
As a special case, return error_mark_node when constructor
|
|
is not explicitly available, but it is known to be zero
|
|
such as 'static const int a;'. */
|
|
static tree
|
|
get_base_constructor (tree base, HOST_WIDE_INT *bit_offset,
|
|
tree (*valueize)(tree))
|
|
{
|
|
HOST_WIDE_INT bit_offset2, size, max_size;
|
|
if (TREE_CODE (base) == MEM_REF)
|
|
{
|
|
if (!integer_zerop (TREE_OPERAND (base, 1)))
|
|
{
|
|
if (!host_integerp (TREE_OPERAND (base, 1), 0))
|
|
return NULL_TREE;
|
|
*bit_offset += (mem_ref_offset (base).low
|
|
* BITS_PER_UNIT);
|
|
}
|
|
|
|
if (valueize
|
|
&& TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
|
|
base = valueize (TREE_OPERAND (base, 0));
|
|
if (!base || TREE_CODE (base) != ADDR_EXPR)
|
|
return NULL_TREE;
|
|
base = TREE_OPERAND (base, 0);
|
|
}
|
|
|
|
/* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its
|
|
DECL_INITIAL. If BASE is a nested reference into another
|
|
ARRAY_REF or COMPONENT_REF, make a recursive call to resolve
|
|
the inner reference. */
|
|
switch (TREE_CODE (base))
|
|
{
|
|
case VAR_DECL:
|
|
if (!const_value_known_p (base))
|
|
return NULL_TREE;
|
|
|
|
/* Fallthru. */
|
|
case CONST_DECL:
|
|
if (!DECL_INITIAL (base)
|
|
&& (TREE_STATIC (base) || DECL_EXTERNAL (base)))
|
|
return error_mark_node;
|
|
return DECL_INITIAL (base);
|
|
|
|
case ARRAY_REF:
|
|
case COMPONENT_REF:
|
|
base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size);
|
|
if (max_size == -1 || size != max_size)
|
|
return NULL_TREE;
|
|
*bit_offset += bit_offset2;
|
|
return get_base_constructor (base, bit_offset, valueize);
|
|
|
|
case STRING_CST:
|
|
case CONSTRUCTOR:
|
|
return base;
|
|
|
|
default:
|
|
return NULL_TREE;
|
|
}
|
|
}
|
|
|
|
/* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE
|
|
to the memory at bit OFFSET.
|
|
|
|
We do only simple job of folding byte accesses. */
|
|
|
|
static tree
|
|
fold_string_cst_ctor_reference (tree type, tree ctor,
|
|
unsigned HOST_WIDE_INT offset,
|
|
unsigned HOST_WIDE_INT size)
|
|
{
|
|
if (INTEGRAL_TYPE_P (type)
|
|
&& (TYPE_MODE (type)
|
|
== TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
|
|
&& (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
|
|
== MODE_INT)
|
|
&& GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1
|
|
&& size == BITS_PER_UNIT
|
|
&& !(offset % BITS_PER_UNIT))
|
|
{
|
|
offset /= BITS_PER_UNIT;
|
|
if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor))
|
|
return build_int_cst_type (type, (TREE_STRING_POINTER (ctor)
|
|
[offset]));
|
|
/* Folding
|
|
const char a[20]="hello";
|
|
return a[10];
|
|
|
|
might lead to offset greater than string length. In this case we
|
|
know value is either initialized to 0 or out of bounds. Return 0
|
|
in both cases. */
|
|
return build_zero_cst (type);
|
|
}
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size
|
|
SIZE to the memory at bit OFFSET. */
|
|
|
|
static tree
|
|
fold_array_ctor_reference (tree type, tree ctor,
|
|
unsigned HOST_WIDE_INT offset,
|
|
unsigned HOST_WIDE_INT size)
|
|
{
|
|
unsigned HOST_WIDE_INT cnt;
|
|
tree cfield, cval;
|
|
double_int low_bound, elt_size;
|
|
double_int index, max_index;
|
|
double_int access_index;
|
|
tree domain_type = TYPE_DOMAIN (TREE_TYPE (ctor));
|
|
HOST_WIDE_INT inner_offset;
|
|
|
|
/* Compute low bound and elt size. */
|
|
if (domain_type && TYPE_MIN_VALUE (domain_type))
|
|
{
|
|
/* Static constructors for variably sized objects makes no sense. */
|
|
gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST);
|
|
low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type));
|
|
}
|
|
else
|
|
low_bound = double_int_zero;
|
|
/* Static constructors for variably sized objects makes no sense. */
|
|
gcc_assert (TREE_CODE(TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor))))
|
|
== INTEGER_CST);
|
|
elt_size =
|
|
tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor))));
|
|
|
|
|
|
/* We can handle only constantly sized accesses that are known to not
|
|
be larger than size of array element. */
|
|
if (!TYPE_SIZE_UNIT (type)
|
|
|| TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
|
|
|| double_int_cmp (elt_size,
|
|
tree_to_double_int (TYPE_SIZE_UNIT (type)), 0) < 0)
|
|
return NULL_TREE;
|
|
|
|
/* Compute the array index we look for. */
|
|
access_index = double_int_udiv (uhwi_to_double_int (offset / BITS_PER_UNIT),
|
|
elt_size, TRUNC_DIV_EXPR);
|
|
access_index = double_int_add (access_index, low_bound);
|
|
|
|
/* And offset within the access. */
|
|
inner_offset = offset % (double_int_to_uhwi (elt_size) * BITS_PER_UNIT);
|
|
|
|
/* See if the array field is large enough to span whole access. We do not
|
|
care to fold accesses spanning multiple array indexes. */
|
|
if (inner_offset + size > double_int_to_uhwi (elt_size) * BITS_PER_UNIT)
|
|
return NULL_TREE;
|
|
|
|
index = double_int_sub (low_bound, double_int_one);
|
|
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
|
|
{
|
|
/* Array constructor might explicitely set index, or specify range
|
|
or leave index NULL meaning that it is next index after previous
|
|
one. */
|
|
if (cfield)
|
|
{
|
|
if (TREE_CODE (cfield) == INTEGER_CST)
|
|
max_index = index = tree_to_double_int (cfield);
|
|
else
|
|
{
|
|
gcc_assert (TREE_CODE (cfield) == RANGE_EXPR);
|
|
index = tree_to_double_int (TREE_OPERAND (cfield, 0));
|
|
max_index = tree_to_double_int (TREE_OPERAND (cfield, 1));
|
|
}
|
|
}
|
|
else
|
|
max_index = index = double_int_add (index, double_int_one);
|
|
|
|
/* Do we have match? */
|
|
if (double_int_cmp (access_index, index, 1) >= 0
|
|
&& double_int_cmp (access_index, max_index, 1) <= 0)
|
|
return fold_ctor_reference (type, cval, inner_offset, size);
|
|
}
|
|
/* When memory is not explicitely mentioned in constructor,
|
|
it is 0 (or out of range). */
|
|
return build_zero_cst (type);
|
|
}
|
|
|
|
/* CTOR is CONSTRUCTOR of an aggregate or vector.
|
|
Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */
|
|
|
|
static tree
|
|
fold_nonarray_ctor_reference (tree type, tree ctor,
|
|
unsigned HOST_WIDE_INT offset,
|
|
unsigned HOST_WIDE_INT size)
|
|
{
|
|
unsigned HOST_WIDE_INT cnt;
|
|
tree cfield, cval;
|
|
|
|
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield,
|
|
cval)
|
|
{
|
|
tree byte_offset = DECL_FIELD_OFFSET (cfield);
|
|
tree field_offset = DECL_FIELD_BIT_OFFSET (cfield);
|
|
tree field_size = DECL_SIZE (cfield);
|
|
double_int bitoffset;
|
|
double_int byte_offset_cst = tree_to_double_int (byte_offset);
|
|
double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT);
|
|
double_int bitoffset_end;
|
|
|
|
/* Variable sized objects in static constructors makes no sense,
|
|
but field_size can be NULL for flexible array members. */
|
|
gcc_assert (TREE_CODE (field_offset) == INTEGER_CST
|
|
&& TREE_CODE (byte_offset) == INTEGER_CST
|
|
&& (field_size != NULL_TREE
|
|
? TREE_CODE (field_size) == INTEGER_CST
|
|
: TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE));
|
|
|
|
/* Compute bit offset of the field. */
|
|
bitoffset = double_int_add (tree_to_double_int (field_offset),
|
|
double_int_mul (byte_offset_cst,
|
|
bits_per_unit_cst));
|
|
/* Compute bit offset where the field ends. */
|
|
if (field_size != NULL_TREE)
|
|
bitoffset_end = double_int_add (bitoffset,
|
|
tree_to_double_int (field_size));
|
|
else
|
|
bitoffset_end = double_int_zero;
|
|
|
|
/* Is OFFSET in the range (BITOFFSET, BITOFFSET_END)? */
|
|
if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) >= 0
|
|
&& (field_size == NULL_TREE
|
|
|| double_int_cmp (uhwi_to_double_int (offset),
|
|
bitoffset_end, 0) < 0))
|
|
{
|
|
double_int access_end = double_int_add (uhwi_to_double_int (offset),
|
|
uhwi_to_double_int (size));
|
|
double_int inner_offset = double_int_sub (uhwi_to_double_int (offset),
|
|
bitoffset);
|
|
/* We do have overlap. Now see if field is large enough to
|
|
cover the access. Give up for accesses spanning multiple
|
|
fields. */
|
|
if (double_int_cmp (access_end, bitoffset_end, 0) > 0)
|
|
return NULL_TREE;
|
|
return fold_ctor_reference (type, cval,
|
|
double_int_to_uhwi (inner_offset), size);
|
|
}
|
|
}
|
|
/* When memory is not explicitely mentioned in constructor, it is 0. */
|
|
return build_zero_cst (type);
|
|
}
|
|
|
|
/* CTOR is value initializing memory, fold reference of type TYPE and size SIZE
|
|
to the memory at bit OFFSET. */
|
|
|
|
static tree
|
|
fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset,
|
|
unsigned HOST_WIDE_INT size)
|
|
{
|
|
tree ret;
|
|
|
|
/* We found the field with exact match. */
|
|
if (useless_type_conversion_p (type, TREE_TYPE (ctor))
|
|
&& !offset)
|
|
return canonicalize_constructor_val (ctor);
|
|
|
|
/* We are at the end of walk, see if we can view convert the
|
|
result. */
|
|
if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset
|
|
/* VIEW_CONVERT_EXPR is defined only for matching sizes. */
|
|
&& operand_equal_p (TYPE_SIZE (type),
|
|
TYPE_SIZE (TREE_TYPE (ctor)), 0))
|
|
{
|
|
ret = canonicalize_constructor_val (ctor);
|
|
ret = fold_unary (VIEW_CONVERT_EXPR, type, ret);
|
|
if (ret)
|
|
STRIP_NOPS (ret);
|
|
return ret;
|
|
}
|
|
if (TREE_CODE (ctor) == STRING_CST)
|
|
return fold_string_cst_ctor_reference (type, ctor, offset, size);
|
|
if (TREE_CODE (ctor) == CONSTRUCTOR)
|
|
{
|
|
|
|
if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE)
|
|
return fold_array_ctor_reference (type, ctor, offset, size);
|
|
else
|
|
return fold_nonarray_ctor_reference (type, ctor, offset, size);
|
|
}
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
/* Return the tree representing the element referenced by T if T is an
|
|
ARRAY_REF or COMPONENT_REF into constant aggregates valuezing SSA
|
|
names using VALUEIZE. Return NULL_TREE otherwise. */
|
|
|
|
tree
|
|
fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree))
|
|
{
|
|
tree ctor, idx, base;
|
|
HOST_WIDE_INT offset, size, max_size;
|
|
tree tem;
|
|
|
|
if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
|
|
return get_symbol_constant_value (t);
|
|
|
|
tem = fold_read_from_constant_string (t);
|
|
if (tem)
|
|
return tem;
|
|
|
|
switch (TREE_CODE (t))
|
|
{
|
|
case ARRAY_REF:
|
|
case ARRAY_RANGE_REF:
|
|
/* Constant indexes are handled well by get_base_constructor.
|
|
Only special case variable offsets.
|
|
FIXME: This code can't handle nested references with variable indexes
|
|
(they will be handled only by iteration of ccp). Perhaps we can bring
|
|
get_ref_base_and_extent here and make it use a valueize callback. */
|
|
if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME
|
|
&& valueize
|
|
&& (idx = (*valueize) (TREE_OPERAND (t, 1)))
|
|
&& host_integerp (idx, 0))
|
|
{
|
|
tree low_bound, unit_size;
|
|
|
|
/* If the resulting bit-offset is constant, track it. */
|
|
if ((low_bound = array_ref_low_bound (t),
|
|
host_integerp (low_bound, 0))
|
|
&& (unit_size = array_ref_element_size (t),
|
|
host_integerp (unit_size, 1)))
|
|
{
|
|
offset = TREE_INT_CST_LOW (idx);
|
|
offset -= TREE_INT_CST_LOW (low_bound);
|
|
offset *= TREE_INT_CST_LOW (unit_size);
|
|
offset *= BITS_PER_UNIT;
|
|
|
|
base = TREE_OPERAND (t, 0);
|
|
ctor = get_base_constructor (base, &offset, valueize);
|
|
/* Empty constructor. Always fold to 0. */
|
|
if (ctor == error_mark_node)
|
|
return build_zero_cst (TREE_TYPE (t));
|
|
/* Out of bound array access. Value is undefined,
|
|
but don't fold. */
|
|
if (offset < 0)
|
|
return NULL_TREE;
|
|
/* We can not determine ctor. */
|
|
if (!ctor)
|
|
return NULL_TREE;
|
|
return fold_ctor_reference (TREE_TYPE (t), ctor, offset,
|
|
TREE_INT_CST_LOW (unit_size)
|
|
* BITS_PER_UNIT);
|
|
}
|
|
}
|
|
/* Fallthru. */
|
|
|
|
case COMPONENT_REF:
|
|
case BIT_FIELD_REF:
|
|
case TARGET_MEM_REF:
|
|
case MEM_REF:
|
|
base = get_ref_base_and_extent (t, &offset, &size, &max_size);
|
|
ctor = get_base_constructor (base, &offset, valueize);
|
|
|
|
/* Empty constructor. Always fold to 0. */
|
|
if (ctor == error_mark_node)
|
|
return build_zero_cst (TREE_TYPE (t));
|
|
/* We do not know precise address. */
|
|
if (max_size == -1 || max_size != size)
|
|
return NULL_TREE;
|
|
/* We can not determine ctor. */
|
|
if (!ctor)
|
|
return NULL_TREE;
|
|
|
|
/* Out of bound array access. Value is undefined, but don't fold. */
|
|
if (offset < 0)
|
|
return NULL_TREE;
|
|
|
|
return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size);
|
|
|
|
case REALPART_EXPR:
|
|
case IMAGPART_EXPR:
|
|
{
|
|
tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize);
|
|
if (c && TREE_CODE (c) == COMPLEX_CST)
|
|
return fold_build1_loc (EXPR_LOCATION (t),
|
|
TREE_CODE (t), TREE_TYPE (t), c);
|
|
break;
|
|
}
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return NULL_TREE;
|
|
}
|
|
|
|
tree
|
|
fold_const_aggregate_ref (tree t)
|
|
{
|
|
return fold_const_aggregate_ref_1 (t, NULL);
|
|
}
|
|
|
|
/* Return true iff VAL is a gimple expression that is known to be
|
|
non-negative. Restricted to floating-point inputs. */
|
|
|
|
bool
|
|
gimple_val_nonnegative_real_p (tree val)
|
|
{
|
|
gimple def_stmt;
|
|
|
|
gcc_assert (val && SCALAR_FLOAT_TYPE_P (TREE_TYPE (val)));
|
|
|
|
/* Use existing logic for non-gimple trees. */
|
|
if (tree_expr_nonnegative_p (val))
|
|
return true;
|
|
|
|
if (TREE_CODE (val) != SSA_NAME)
|
|
return false;
|
|
|
|
/* Currently we look only at the immediately defining statement
|
|
to make this determination, since recursion on defining
|
|
statements of operands can lead to quadratic behavior in the
|
|
worst case. This is expected to catch almost all occurrences
|
|
in practice. It would be possible to implement limited-depth
|
|
recursion if important cases are lost. Alternatively, passes
|
|
that need this information (such as the pow/powi lowering code
|
|
in the cse_sincos pass) could be revised to provide it through
|
|
dataflow propagation. */
|
|
|
|
def_stmt = SSA_NAME_DEF_STMT (val);
|
|
|
|
if (is_gimple_assign (def_stmt))
|
|
{
|
|
tree op0, op1;
|
|
|
|
/* See fold-const.c:tree_expr_nonnegative_p for additional
|
|
cases that could be handled with recursion. */
|
|
|
|
switch (gimple_assign_rhs_code (def_stmt))
|
|
{
|
|
case ABS_EXPR:
|
|
/* Always true for floating-point operands. */
|
|
return true;
|
|
|
|
case MULT_EXPR:
|
|
/* True if the two operands are identical (since we are
|
|
restricted to floating-point inputs). */
|
|
op0 = gimple_assign_rhs1 (def_stmt);
|
|
op1 = gimple_assign_rhs2 (def_stmt);
|
|
|
|
if (op0 == op1
|
|
|| operand_equal_p (op0, op1, 0))
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
else if (is_gimple_call (def_stmt))
|
|
{
|
|
tree fndecl = gimple_call_fndecl (def_stmt);
|
|
if (fndecl
|
|
&& DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
|
|
{
|
|
tree arg1;
|
|
|
|
switch (DECL_FUNCTION_CODE (fndecl))
|
|
{
|
|
CASE_FLT_FN (BUILT_IN_ACOS):
|
|
CASE_FLT_FN (BUILT_IN_ACOSH):
|
|
CASE_FLT_FN (BUILT_IN_CABS):
|
|
CASE_FLT_FN (BUILT_IN_COSH):
|
|
CASE_FLT_FN (BUILT_IN_ERFC):
|
|
CASE_FLT_FN (BUILT_IN_EXP):
|
|
CASE_FLT_FN (BUILT_IN_EXP10):
|
|
CASE_FLT_FN (BUILT_IN_EXP2):
|
|
CASE_FLT_FN (BUILT_IN_FABS):
|
|
CASE_FLT_FN (BUILT_IN_FDIM):
|
|
CASE_FLT_FN (BUILT_IN_HYPOT):
|
|
CASE_FLT_FN (BUILT_IN_POW10):
|
|
return true;
|
|
|
|
CASE_FLT_FN (BUILT_IN_SQRT):
|
|
/* sqrt(-0.0) is -0.0, and sqrt is not defined over other
|
|
nonnegative inputs. */
|
|
if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (val))))
|
|
return true;
|
|
|
|
break;
|
|
|
|
CASE_FLT_FN (BUILT_IN_POWI):
|
|
/* True if the second argument is an even integer. */
|
|
arg1 = gimple_call_arg (def_stmt, 1);
|
|
|
|
if (TREE_CODE (arg1) == INTEGER_CST
|
|
&& (TREE_INT_CST_LOW (arg1) & 1) == 0)
|
|
return true;
|
|
|
|
break;
|
|
|
|
CASE_FLT_FN (BUILT_IN_POW):
|
|
/* True if the second argument is an even integer-valued
|
|
real. */
|
|
arg1 = gimple_call_arg (def_stmt, 1);
|
|
|
|
if (TREE_CODE (arg1) == REAL_CST)
|
|
{
|
|
REAL_VALUE_TYPE c;
|
|
HOST_WIDE_INT n;
|
|
|
|
c = TREE_REAL_CST (arg1);
|
|
n = real_to_integer (&c);
|
|
|
|
if ((n & 1) == 0)
|
|
{
|
|
REAL_VALUE_TYPE cint;
|
|
real_from_integer (&cint, VOIDmode, n, n < 0 ? -1 : 0, 0);
|
|
if (real_identical (&c, &cint))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
break;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|