/* Alias analysis for GNU C
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/* Alias analysis for GNU C
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Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
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Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
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2007 Free Software Foundation, Inc.
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2007 Free Software Foundation, Inc.
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Contributed by John Carr (jfc@mit.edu).
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Contributed by John Carr (jfc@mit.edu).
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This file is part of GCC.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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Software Foundation; either version 3, or (at your option) any later
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version.
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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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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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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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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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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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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<http://www.gnu.org/licenses/>. */
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#include "config.h"
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#include "config.h"
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#include "system.h"
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#include "system.h"
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#include "coretypes.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "tm.h"
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#include "rtl.h"
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#include "rtl.h"
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#include "tree.h"
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#include "tree.h"
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#include "tm_p.h"
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#include "tm_p.h"
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#include "function.h"
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#include "function.h"
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#include "alias.h"
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#include "alias.h"
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#include "emit-rtl.h"
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#include "emit-rtl.h"
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#include "regs.h"
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#include "regs.h"
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#include "hard-reg-set.h"
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#include "hard-reg-set.h"
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#include "basic-block.h"
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#include "basic-block.h"
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#include "flags.h"
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#include "flags.h"
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#include "output.h"
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#include "output.h"
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#include "toplev.h"
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#include "toplev.h"
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#include "cselib.h"
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#include "cselib.h"
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#include "splay-tree.h"
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#include "splay-tree.h"
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#include "ggc.h"
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#include "ggc.h"
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#include "langhooks.h"
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#include "langhooks.h"
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#include "timevar.h"
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#include "timevar.h"
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#include "target.h"
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#include "target.h"
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#include "cgraph.h"
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#include "cgraph.h"
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#include "varray.h"
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#include "varray.h"
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#include "tree-pass.h"
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#include "tree-pass.h"
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#include "ipa-type-escape.h"
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#include "ipa-type-escape.h"
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/* The aliasing API provided here solves related but different problems:
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/* The aliasing API provided here solves related but different problems:
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Say there exists (in c)
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Say there exists (in c)
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struct X {
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struct X {
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struct Y y1;
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struct Y y1;
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struct Z z2;
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struct Z z2;
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} x1, *px1, *px2;
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} x1, *px1, *px2;
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struct Y y2, *py;
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struct Y y2, *py;
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struct Z z2, *pz;
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struct Z z2, *pz;
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py = &px1.y1;
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py = &px1.y1;
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px2 = &x1;
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px2 = &x1;
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Consider the four questions:
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Consider the four questions:
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Can a store to x1 interfere with px2->y1?
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Can a store to x1 interfere with px2->y1?
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Can a store to x1 interfere with px2->z2?
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Can a store to x1 interfere with px2->z2?
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(*px2).z2
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(*px2).z2
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Can a store to x1 change the value pointed to by with py?
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Can a store to x1 change the value pointed to by with py?
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Can a store to x1 change the value pointed to by with pz?
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Can a store to x1 change the value pointed to by with pz?
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The answer to these questions can be yes, yes, yes, and maybe.
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The answer to these questions can be yes, yes, yes, and maybe.
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The first two questions can be answered with a simple examination
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The first two questions can be answered with a simple examination
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of the type system. If structure X contains a field of type Y then
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of the type system. If structure X contains a field of type Y then
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a store thru a pointer to an X can overwrite any field that is
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a store thru a pointer to an X can overwrite any field that is
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contained (recursively) in an X (unless we know that px1 != px2).
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contained (recursively) in an X (unless we know that px1 != px2).
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The last two of the questions can be solved in the same way as the
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The last two of the questions can be solved in the same way as the
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first two questions but this is too conservative. The observation
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first two questions but this is too conservative. The observation
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is that in some cases analysis we can know if which (if any) fields
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is that in some cases analysis we can know if which (if any) fields
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are addressed and if those addresses are used in bad ways. This
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are addressed and if those addresses are used in bad ways. This
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analysis may be language specific. In C, arbitrary operations may
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analysis may be language specific. In C, arbitrary operations may
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be applied to pointers. However, there is some indication that
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be applied to pointers. However, there is some indication that
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this may be too conservative for some C++ types.
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this may be too conservative for some C++ types.
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The pass ipa-type-escape does this analysis for the types whose
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The pass ipa-type-escape does this analysis for the types whose
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instances do not escape across the compilation boundary.
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instances do not escape across the compilation boundary.
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Historically in GCC, these two problems were combined and a single
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Historically in GCC, these two problems were combined and a single
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data structure was used to represent the solution to these
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data structure was used to represent the solution to these
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problems. We now have two similar but different data structures,
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problems. We now have two similar but different data structures,
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The data structure to solve the last two question is similar to the
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The data structure to solve the last two question is similar to the
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first, but does not contain have the fields in it whose address are
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first, but does not contain have the fields in it whose address are
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never taken. For types that do escape the compilation unit, the
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never taken. For types that do escape the compilation unit, the
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data structures will have identical information.
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data structures will have identical information.
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*/
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*/
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/* The alias sets assigned to MEMs assist the back-end in determining
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/* The alias sets assigned to MEMs assist the back-end in determining
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which MEMs can alias which other MEMs. In general, two MEMs in
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which MEMs can alias which other MEMs. In general, two MEMs in
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different alias sets cannot alias each other, with one important
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different alias sets cannot alias each other, with one important
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exception. Consider something like:
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exception. Consider something like:
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struct S { int i; double d; };
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struct S { int i; double d; };
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a store to an `S' can alias something of either type `int' or type
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a store to an `S' can alias something of either type `int' or type
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`double'. (However, a store to an `int' cannot alias a `double'
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`double'. (However, a store to an `int' cannot alias a `double'
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and vice versa.) We indicate this via a tree structure that looks
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and vice versa.) We indicate this via a tree structure that looks
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like:
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like:
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struct S
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struct S
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/ \
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/ \
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/ \
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/ \
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|/_ _\|
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|/_ _\|
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int double
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int double
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(The arrows are directed and point downwards.)
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(The arrows are directed and point downwards.)
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In this situation we say the alias set for `struct S' is the
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In this situation we say the alias set for `struct S' is the
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`superset' and that those for `int' and `double' are `subsets'.
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`superset' and that those for `int' and `double' are `subsets'.
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To see whether two alias sets can point to the same memory, we must
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To see whether two alias sets can point to the same memory, we must
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see if either alias set is a subset of the other. We need not trace
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see if either alias set is a subset of the other. We need not trace
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past immediate descendants, however, since we propagate all
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past immediate descendants, however, since we propagate all
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grandchildren up one level.
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grandchildren up one level.
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Alias set zero is implicitly a superset of all other alias sets.
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Alias set zero is implicitly a superset of all other alias sets.
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However, this is no actual entry for alias set zero. It is an
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However, this is no actual entry for alias set zero. It is an
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error to attempt to explicitly construct a subset of zero. */
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error to attempt to explicitly construct a subset of zero. */
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struct alias_set_entry GTY(())
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struct alias_set_entry GTY(())
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{
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{
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/* The alias set number, as stored in MEM_ALIAS_SET. */
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/* The alias set number, as stored in MEM_ALIAS_SET. */
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HOST_WIDE_INT alias_set;
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HOST_WIDE_INT alias_set;
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/* The children of the alias set. These are not just the immediate
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/* The children of the alias set. These are not just the immediate
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children, but, in fact, all descendants. So, if we have:
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children, but, in fact, all descendants. So, if we have:
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struct T { struct S s; float f; }
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struct T { struct S s; float f; }
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continuing our example above, the children here will be all of
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continuing our example above, the children here will be all of
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`int', `double', `float', and `struct S'. */
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`int', `double', `float', and `struct S'. */
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splay_tree GTY((param1_is (int), param2_is (int))) children;
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splay_tree GTY((param1_is (int), param2_is (int))) children;
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/* Nonzero if would have a child of zero: this effectively makes this
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/* Nonzero if would have a child of zero: this effectively makes this
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alias set the same as alias set zero. */
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alias set the same as alias set zero. */
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int has_zero_child;
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int has_zero_child;
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};
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};
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typedef struct alias_set_entry *alias_set_entry;
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typedef struct alias_set_entry *alias_set_entry;
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static int rtx_equal_for_memref_p (rtx, rtx);
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static int rtx_equal_for_memref_p (rtx, rtx);
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static rtx find_symbolic_term (rtx);
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static rtx find_symbolic_term (rtx);
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static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT);
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static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT);
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static void record_set (rtx, rtx, void *);
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static void record_set (rtx, rtx, void *);
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static int base_alias_check (rtx, rtx, enum machine_mode,
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static int base_alias_check (rtx, rtx, enum machine_mode,
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enum machine_mode);
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enum machine_mode);
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static rtx find_base_value (rtx);
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static rtx find_base_value (rtx);
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static int mems_in_disjoint_alias_sets_p (rtx, rtx);
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static int mems_in_disjoint_alias_sets_p (rtx, rtx);
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static int insert_subset_children (splay_tree_node, void*);
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static int insert_subset_children (splay_tree_node, void*);
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static tree find_base_decl (tree);
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static tree find_base_decl (tree);
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static alias_set_entry get_alias_set_entry (HOST_WIDE_INT);
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static alias_set_entry get_alias_set_entry (HOST_WIDE_INT);
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static rtx fixed_scalar_and_varying_struct_p (rtx, rtx, rtx, rtx,
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static rtx fixed_scalar_and_varying_struct_p (rtx, rtx, rtx, rtx,
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int (*) (rtx, int));
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int (*) (rtx, int));
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static int aliases_everything_p (rtx);
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static int aliases_everything_p (rtx);
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static bool nonoverlapping_component_refs_p (tree, tree);
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static bool nonoverlapping_component_refs_p (tree, tree);
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static tree decl_for_component_ref (tree);
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static tree decl_for_component_ref (tree);
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static rtx adjust_offset_for_component_ref (tree, rtx);
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static rtx adjust_offset_for_component_ref (tree, rtx);
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static int nonoverlapping_memrefs_p (rtx, rtx);
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static int nonoverlapping_memrefs_p (rtx, rtx);
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static int write_dependence_p (rtx, rtx, int);
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static int write_dependence_p (rtx, rtx, int);
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static void memory_modified_1 (rtx, rtx, void *);
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static void memory_modified_1 (rtx, rtx, void *);
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static void record_alias_subset (HOST_WIDE_INT, HOST_WIDE_INT);
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static void record_alias_subset (HOST_WIDE_INT, HOST_WIDE_INT);
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/* Set up all info needed to perform alias analysis on memory references. */
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/* Set up all info needed to perform alias analysis on memory references. */
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/* Returns the size in bytes of the mode of X. */
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/* Returns the size in bytes of the mode of X. */
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#define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X)))
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#define SIZE_FOR_MODE(X) (GET_MODE_SIZE (GET_MODE (X)))
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/* Returns nonzero if MEM1 and MEM2 do not alias because they are in
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/* Returns nonzero if MEM1 and MEM2 do not alias because they are in
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different alias sets. We ignore alias sets in functions making use
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different alias sets. We ignore alias sets in functions making use
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of variable arguments because the va_arg macros on some systems are
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of variable arguments because the va_arg macros on some systems are
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not legal ANSI C. */
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not legal ANSI C. */
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#define DIFFERENT_ALIAS_SETS_P(MEM1, MEM2) \
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#define DIFFERENT_ALIAS_SETS_P(MEM1, MEM2) \
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mems_in_disjoint_alias_sets_p (MEM1, MEM2)
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mems_in_disjoint_alias_sets_p (MEM1, MEM2)
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/* Cap the number of passes we make over the insns propagating alias
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/* Cap the number of passes we make over the insns propagating alias
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information through set chains. 10 is a completely arbitrary choice. */
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information through set chains. 10 is a completely arbitrary choice. */
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#define MAX_ALIAS_LOOP_PASSES 10
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#define MAX_ALIAS_LOOP_PASSES 10
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/* reg_base_value[N] gives an address to which register N is related.
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/* reg_base_value[N] gives an address to which register N is related.
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If all sets after the first add or subtract to the current value
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If all sets after the first add or subtract to the current value
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or otherwise modify it so it does not point to a different top level
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or otherwise modify it so it does not point to a different top level
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object, reg_base_value[N] is equal to the address part of the source
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object, reg_base_value[N] is equal to the address part of the source
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of the first set.
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of the first set.
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A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS
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A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS
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expressions represent certain special values: function arguments and
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expressions represent certain special values: function arguments and
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the stack, frame, and argument pointers.
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the stack, frame, and argument pointers.
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The contents of an ADDRESS is not normally used, the mode of the
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The contents of an ADDRESS is not normally used, the mode of the
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ADDRESS determines whether the ADDRESS is a function argument or some
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ADDRESS determines whether the ADDRESS is a function argument or some
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other special value. Pointer equality, not rtx_equal_p, determines whether
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other special value. Pointer equality, not rtx_equal_p, determines whether
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two ADDRESS expressions refer to the same base address.
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two ADDRESS expressions refer to the same base address.
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The only use of the contents of an ADDRESS is for determining if the
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The only use of the contents of an ADDRESS is for determining if the
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current function performs nonlocal memory memory references for the
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current function performs nonlocal memory memory references for the
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purposes of marking the function as a constant function. */
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purposes of marking the function as a constant function. */
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static GTY(()) VEC(rtx,gc) *reg_base_value;
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static GTY(()) VEC(rtx,gc) *reg_base_value;
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static rtx *new_reg_base_value;
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static rtx *new_reg_base_value;
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/* We preserve the copy of old array around to avoid amount of garbage
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/* We preserve the copy of old array around to avoid amount of garbage
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produced. About 8% of garbage produced were attributed to this
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produced. About 8% of garbage produced were attributed to this
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array. */
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array. */
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static GTY((deletable)) VEC(rtx,gc) *old_reg_base_value;
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static GTY((deletable)) VEC(rtx,gc) *old_reg_base_value;
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/* Static hunks of RTL used by the aliasing code; these are initialized
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/* Static hunks of RTL used by the aliasing code; these are initialized
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once per function to avoid unnecessary RTL allocations. */
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once per function to avoid unnecessary RTL allocations. */
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static GTY (()) rtx static_reg_base_value[FIRST_PSEUDO_REGISTER];
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static GTY (()) rtx static_reg_base_value[FIRST_PSEUDO_REGISTER];
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#define REG_BASE_VALUE(X) \
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#define REG_BASE_VALUE(X) \
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(REGNO (X) < VEC_length (rtx, reg_base_value) \
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(REGNO (X) < VEC_length (rtx, reg_base_value) \
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? VEC_index (rtx, reg_base_value, REGNO (X)) : 0)
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? VEC_index (rtx, reg_base_value, REGNO (X)) : 0)
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/* Vector indexed by N giving the initial (unchanging) value known for
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/* Vector indexed by N giving the initial (unchanging) value known for
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pseudo-register N. This array is initialized in init_alias_analysis,
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pseudo-register N. This array is initialized in init_alias_analysis,
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and does not change until end_alias_analysis is called. */
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and does not change until end_alias_analysis is called. */
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static GTY((length("reg_known_value_size"))) rtx *reg_known_value;
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static GTY((length("reg_known_value_size"))) rtx *reg_known_value;
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/* Indicates number of valid entries in reg_known_value. */
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/* Indicates number of valid entries in reg_known_value. */
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static GTY(()) unsigned int reg_known_value_size;
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static GTY(()) unsigned int reg_known_value_size;
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/* Vector recording for each reg_known_value whether it is due to a
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/* Vector recording for each reg_known_value whether it is due to a
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REG_EQUIV note. Future passes (viz., reload) may replace the
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REG_EQUIV note. Future passes (viz., reload) may replace the
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pseudo with the equivalent expression and so we account for the
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pseudo with the equivalent expression and so we account for the
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dependences that would be introduced if that happens.
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dependences that would be introduced if that happens.
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The REG_EQUIV notes created in assign_parms may mention the arg
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The REG_EQUIV notes created in assign_parms may mention the arg
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pointer, and there are explicit insns in the RTL that modify the
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pointer, and there are explicit insns in the RTL that modify the
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arg pointer. Thus we must ensure that such insns don't get
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arg pointer. Thus we must ensure that such insns don't get
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scheduled across each other because that would invalidate the
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scheduled across each other because that would invalidate the
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REG_EQUIV notes. One could argue that the REG_EQUIV notes are
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REG_EQUIV notes. One could argue that the REG_EQUIV notes are
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wrong, but solving the problem in the scheduler will likely give
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wrong, but solving the problem in the scheduler will likely give
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better code, so we do it here. */
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better code, so we do it here. */
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static bool *reg_known_equiv_p;
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static bool *reg_known_equiv_p;
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/* True when scanning insns from the start of the rtl to the
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/* True when scanning insns from the start of the rtl to the
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NOTE_INSN_FUNCTION_BEG note. */
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NOTE_INSN_FUNCTION_BEG note. */
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static bool copying_arguments;
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static bool copying_arguments;
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DEF_VEC_P(alias_set_entry);
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DEF_VEC_P(alias_set_entry);
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DEF_VEC_ALLOC_P(alias_set_entry,gc);
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DEF_VEC_ALLOC_P(alias_set_entry,gc);
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/* The splay-tree used to store the various alias set entries. */
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/* The splay-tree used to store the various alias set entries. */
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static GTY (()) VEC(alias_set_entry,gc) *alias_sets;
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static GTY (()) VEC(alias_set_entry,gc) *alias_sets;
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/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
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/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
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such an entry, or NULL otherwise. */
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such an entry, or NULL otherwise. */
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static inline alias_set_entry
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static inline alias_set_entry
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get_alias_set_entry (HOST_WIDE_INT alias_set)
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get_alias_set_entry (HOST_WIDE_INT alias_set)
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{
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{
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return VEC_index (alias_set_entry, alias_sets, alias_set);
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return VEC_index (alias_set_entry, alias_sets, alias_set);
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}
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}
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/* Returns nonzero if the alias sets for MEM1 and MEM2 are such that
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/* Returns nonzero if the alias sets for MEM1 and MEM2 are such that
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the two MEMs cannot alias each other. */
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the two MEMs cannot alias each other. */
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static inline int
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static inline int
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mems_in_disjoint_alias_sets_p (rtx mem1, rtx mem2)
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mems_in_disjoint_alias_sets_p (rtx mem1, rtx mem2)
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{
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{
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/* Perform a basic sanity check. Namely, that there are no alias sets
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/* Perform a basic sanity check. Namely, that there are no alias sets
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if we're not using strict aliasing. This helps to catch bugs
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if we're not using strict aliasing. This helps to catch bugs
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whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or
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whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or
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where a MEM is allocated in some way other than by the use of
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where a MEM is allocated in some way other than by the use of
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gen_rtx_MEM, and the MEM_ALIAS_SET is not cleared. If we begin to
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gen_rtx_MEM, and the MEM_ALIAS_SET is not cleared. If we begin to
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use alias sets to indicate that spilled registers cannot alias each
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use alias sets to indicate that spilled registers cannot alias each
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other, we might need to remove this check. */
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other, we might need to remove this check. */
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gcc_assert (flag_strict_aliasing
|
gcc_assert (flag_strict_aliasing
|
|| (!MEM_ALIAS_SET (mem1) && !MEM_ALIAS_SET (mem2)));
|
|| (!MEM_ALIAS_SET (mem1) && !MEM_ALIAS_SET (mem2)));
|
|
|
return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2));
|
return ! alias_sets_conflict_p (MEM_ALIAS_SET (mem1), MEM_ALIAS_SET (mem2));
|
}
|
}
|
|
|
/* Insert the NODE into the splay tree given by DATA. Used by
|
/* Insert the NODE into the splay tree given by DATA. Used by
|
record_alias_subset via splay_tree_foreach. */
|
record_alias_subset via splay_tree_foreach. */
|
|
|
static int
|
static int
|
insert_subset_children (splay_tree_node node, void *data)
|
insert_subset_children (splay_tree_node node, void *data)
|
{
|
{
|
splay_tree_insert ((splay_tree) data, node->key, node->value);
|
splay_tree_insert ((splay_tree) data, node->key, node->value);
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Return 1 if the two specified alias sets may conflict. */
|
/* Return 1 if the two specified alias sets may conflict. */
|
|
|
int
|
int
|
alias_sets_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2)
|
alias_sets_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2)
|
{
|
{
|
alias_set_entry ase;
|
alias_set_entry ase;
|
|
|
/* If have no alias set information for one of the operands, we have
|
/* If have no alias set information for one of the operands, we have
|
to assume it can alias anything. */
|
to assume it can alias anything. */
|
if (set1 == 0 || set2 == 0
|
if (set1 == 0 || set2 == 0
|
/* If the two alias sets are the same, they may alias. */
|
/* If the two alias sets are the same, they may alias. */
|
|| set1 == set2)
|
|| set1 == set2)
|
return 1;
|
return 1;
|
|
|
/* See if the first alias set is a subset of the second. */
|
/* See if the first alias set is a subset of the second. */
|
ase = get_alias_set_entry (set1);
|
ase = get_alias_set_entry (set1);
|
if (ase != 0
|
if (ase != 0
|
&& (ase->has_zero_child
|
&& (ase->has_zero_child
|
|| splay_tree_lookup (ase->children,
|
|| splay_tree_lookup (ase->children,
|
(splay_tree_key) set2)))
|
(splay_tree_key) set2)))
|
return 1;
|
return 1;
|
|
|
/* Now do the same, but with the alias sets reversed. */
|
/* Now do the same, but with the alias sets reversed. */
|
ase = get_alias_set_entry (set2);
|
ase = get_alias_set_entry (set2);
|
if (ase != 0
|
if (ase != 0
|
&& (ase->has_zero_child
|
&& (ase->has_zero_child
|
|| splay_tree_lookup (ase->children,
|
|| splay_tree_lookup (ase->children,
|
(splay_tree_key) set1)))
|
(splay_tree_key) set1)))
|
return 1;
|
return 1;
|
|
|
/* The two alias sets are distinct and neither one is the
|
/* The two alias sets are distinct and neither one is the
|
child of the other. Therefore, they cannot alias. */
|
child of the other. Therefore, they cannot alias. */
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Return 1 if the two specified alias sets might conflict, or if any subtype
|
/* Return 1 if the two specified alias sets might conflict, or if any subtype
|
of these alias sets might conflict. */
|
of these alias sets might conflict. */
|
|
|
int
|
int
|
alias_sets_might_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2)
|
alias_sets_might_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2)
|
{
|
{
|
if (set1 == 0 || set2 == 0 || set1 == set2)
|
if (set1 == 0 || set2 == 0 || set1 == set2)
|
return 1;
|
return 1;
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
|
|
/* Return 1 if any MEM object of type T1 will always conflict (using the
|
/* Return 1 if any MEM object of type T1 will always conflict (using the
|
dependency routines in this file) with any MEM object of type T2.
|
dependency routines in this file) with any MEM object of type T2.
|
This is used when allocating temporary storage. If T1 and/or T2 are
|
This is used when allocating temporary storage. If T1 and/or T2 are
|
NULL_TREE, it means we know nothing about the storage. */
|
NULL_TREE, it means we know nothing about the storage. */
|
|
|
int
|
int
|
objects_must_conflict_p (tree t1, tree t2)
|
objects_must_conflict_p (tree t1, tree t2)
|
{
|
{
|
HOST_WIDE_INT set1, set2;
|
HOST_WIDE_INT set1, set2;
|
|
|
/* If neither has a type specified, we don't know if they'll conflict
|
/* If neither has a type specified, we don't know if they'll conflict
|
because we may be using them to store objects of various types, for
|
because we may be using them to store objects of various types, for
|
example the argument and local variables areas of inlined functions. */
|
example the argument and local variables areas of inlined functions. */
|
if (t1 == 0 && t2 == 0)
|
if (t1 == 0 && t2 == 0)
|
return 0;
|
return 0;
|
|
|
/* If they are the same type, they must conflict. */
|
/* If they are the same type, they must conflict. */
|
if (t1 == t2
|
if (t1 == t2
|
/* Likewise if both are volatile. */
|
/* Likewise if both are volatile. */
|
|| (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2)))
|
|| (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2)))
|
return 1;
|
return 1;
|
|
|
set1 = t1 ? get_alias_set (t1) : 0;
|
set1 = t1 ? get_alias_set (t1) : 0;
|
set2 = t2 ? get_alias_set (t2) : 0;
|
set2 = t2 ? get_alias_set (t2) : 0;
|
|
|
/* Otherwise they conflict if they have no alias set or the same. We
|
/* Otherwise they conflict if they have no alias set or the same. We
|
can't simply use alias_sets_conflict_p here, because we must make
|
can't simply use alias_sets_conflict_p here, because we must make
|
sure that every subtype of t1 will conflict with every subtype of
|
sure that every subtype of t1 will conflict with every subtype of
|
t2 for which a pair of subobjects of these respective subtypes
|
t2 for which a pair of subobjects of these respective subtypes
|
overlaps on the stack. */
|
overlaps on the stack. */
|
return set1 == 0 || set2 == 0 || set1 == set2;
|
return set1 == 0 || set2 == 0 || set1 == set2;
|
}
|
}
|
|
|
/* T is an expression with pointer type. Find the DECL on which this
|
/* T is an expression with pointer type. Find the DECL on which this
|
expression is based. (For example, in `a[i]' this would be `a'.)
|
expression is based. (For example, in `a[i]' this would be `a'.)
|
If there is no such DECL, or a unique decl cannot be determined,
|
If there is no such DECL, or a unique decl cannot be determined,
|
NULL_TREE is returned. */
|
NULL_TREE is returned. */
|
|
|
static tree
|
static tree
|
find_base_decl (tree t)
|
find_base_decl (tree t)
|
{
|
{
|
tree d0, d1;
|
tree d0, d1;
|
|
|
if (t == 0 || t == error_mark_node || ! POINTER_TYPE_P (TREE_TYPE (t)))
|
if (t == 0 || t == error_mark_node || ! POINTER_TYPE_P (TREE_TYPE (t)))
|
return 0;
|
return 0;
|
|
|
/* If this is a declaration, return it. If T is based on a restrict
|
/* If this is a declaration, return it. If T is based on a restrict
|
qualified decl, return that decl. */
|
qualified decl, return that decl. */
|
if (DECL_P (t))
|
if (DECL_P (t))
|
{
|
{
|
if (TREE_CODE (t) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (t))
|
if (TREE_CODE (t) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (t))
|
t = DECL_GET_RESTRICT_BASE (t);
|
t = DECL_GET_RESTRICT_BASE (t);
|
return t;
|
return t;
|
}
|
}
|
|
|
/* Handle general expressions. It would be nice to deal with
|
/* Handle general expressions. It would be nice to deal with
|
COMPONENT_REFs here. If we could tell that `a' and `b' were the
|
COMPONENT_REFs here. If we could tell that `a' and `b' were the
|
same, then `a->f' and `b->f' are also the same. */
|
same, then `a->f' and `b->f' are also the same. */
|
switch (TREE_CODE_CLASS (TREE_CODE (t)))
|
switch (TREE_CODE_CLASS (TREE_CODE (t)))
|
{
|
{
|
case tcc_unary:
|
case tcc_unary:
|
return find_base_decl (TREE_OPERAND (t, 0));
|
return find_base_decl (TREE_OPERAND (t, 0));
|
|
|
case tcc_binary:
|
case tcc_binary:
|
/* Return 0 if found in neither or both are the same. */
|
/* Return 0 if found in neither or both are the same. */
|
d0 = find_base_decl (TREE_OPERAND (t, 0));
|
d0 = find_base_decl (TREE_OPERAND (t, 0));
|
d1 = find_base_decl (TREE_OPERAND (t, 1));
|
d1 = find_base_decl (TREE_OPERAND (t, 1));
|
if (d0 == d1)
|
if (d0 == d1)
|
return d0;
|
return d0;
|
else if (d0 == 0)
|
else if (d0 == 0)
|
return d1;
|
return d1;
|
else if (d1 == 0)
|
else if (d1 == 0)
|
return d0;
|
return d0;
|
else
|
else
|
return 0;
|
return 0;
|
|
|
default:
|
default:
|
return 0;
|
return 0;
|
}
|
}
|
}
|
}
|
|
|
/* Return true if all nested component references handled by
|
/* Return true if all nested component references handled by
|
get_inner_reference in T are such that we should use the alias set
|
get_inner_reference in T are such that we should use the alias set
|
provided by the object at the heart of T.
|
provided by the object at the heart of T.
|
|
|
This is true for non-addressable components (which don't have their
|
This is true for non-addressable components (which don't have their
|
own alias set), as well as components of objects in alias set zero.
|
own alias set), as well as components of objects in alias set zero.
|
This later point is a special case wherein we wish to override the
|
This later point is a special case wherein we wish to override the
|
alias set used by the component, but we don't have per-FIELD_DECL
|
alias set used by the component, but we don't have per-FIELD_DECL
|
assignable alias sets. */
|
assignable alias sets. */
|
|
|
bool
|
bool
|
component_uses_parent_alias_set (tree t)
|
component_uses_parent_alias_set (tree t)
|
{
|
{
|
while (1)
|
while (1)
|
{
|
{
|
/* If we're at the end, it vacuously uses its own alias set. */
|
/* If we're at the end, it vacuously uses its own alias set. */
|
if (!handled_component_p (t))
|
if (!handled_component_p (t))
|
return false;
|
return false;
|
|
|
switch (TREE_CODE (t))
|
switch (TREE_CODE (t))
|
{
|
{
|
case COMPONENT_REF:
|
case COMPONENT_REF:
|
if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1)))
|
if (DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1)))
|
return true;
|
return true;
|
break;
|
break;
|
|
|
case ARRAY_REF:
|
case ARRAY_REF:
|
case ARRAY_RANGE_REF:
|
case ARRAY_RANGE_REF:
|
if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0))))
|
if (TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0))))
|
return true;
|
return true;
|
break;
|
break;
|
|
|
case REALPART_EXPR:
|
case REALPART_EXPR:
|
case IMAGPART_EXPR:
|
case IMAGPART_EXPR:
|
break;
|
break;
|
|
|
default:
|
default:
|
/* Bitfields and casts are never addressable. */
|
/* Bitfields and casts are never addressable. */
|
return true;
|
return true;
|
}
|
}
|
|
|
t = TREE_OPERAND (t, 0);
|
t = TREE_OPERAND (t, 0);
|
if (get_alias_set (TREE_TYPE (t)) == 0)
|
if (get_alias_set (TREE_TYPE (t)) == 0)
|
return true;
|
return true;
|
}
|
}
|
}
|
}
|
|
|
/* Return the alias set for T, which may be either a type or an
|
/* Return the alias set for T, which may be either a type or an
|
expression. Call language-specific routine for help, if needed. */
|
expression. Call language-specific routine for help, if needed. */
|
|
|
HOST_WIDE_INT
|
HOST_WIDE_INT
|
get_alias_set (tree t)
|
get_alias_set (tree t)
|
{
|
{
|
HOST_WIDE_INT set;
|
HOST_WIDE_INT set;
|
|
|
/* If we're not doing any alias analysis, just assume everything
|
/* If we're not doing any alias analysis, just assume everything
|
aliases everything else. Also return 0 if this or its type is
|
aliases everything else. Also return 0 if this or its type is
|
an error. */
|
an error. */
|
if (! flag_strict_aliasing || t == error_mark_node
|
if (! flag_strict_aliasing || t == error_mark_node
|
|| (! TYPE_P (t)
|
|| (! TYPE_P (t)
|
&& (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node)))
|
&& (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node)))
|
return 0;
|
return 0;
|
|
|
/* We can be passed either an expression or a type. This and the
|
/* We can be passed either an expression or a type. This and the
|
language-specific routine may make mutually-recursive calls to each other
|
language-specific routine may make mutually-recursive calls to each other
|
to figure out what to do. At each juncture, we see if this is a tree
|
to figure out what to do. At each juncture, we see if this is a tree
|
that the language may need to handle specially. First handle things that
|
that the language may need to handle specially. First handle things that
|
aren't types. */
|
aren't types. */
|
if (! TYPE_P (t))
|
if (! TYPE_P (t))
|
{
|
{
|
tree inner = t;
|
tree inner = t;
|
|
|
/* Remove any nops, then give the language a chance to do
|
/* Remove any nops, then give the language a chance to do
|
something with this tree before we look at it. */
|
something with this tree before we look at it. */
|
STRIP_NOPS (t);
|
STRIP_NOPS (t);
|
set = lang_hooks.get_alias_set (t);
|
set = lang_hooks.get_alias_set (t);
|
if (set != -1)
|
if (set != -1)
|
return set;
|
return set;
|
|
|
/* First see if the actual object referenced is an INDIRECT_REF from a
|
/* First see if the actual object referenced is an INDIRECT_REF from a
|
restrict-qualified pointer or a "void *". */
|
restrict-qualified pointer or a "void *". */
|
while (handled_component_p (inner))
|
while (handled_component_p (inner))
|
{
|
{
|
inner = TREE_OPERAND (inner, 0);
|
inner = TREE_OPERAND (inner, 0);
|
STRIP_NOPS (inner);
|
STRIP_NOPS (inner);
|
}
|
}
|
|
|
/* Check for accesses through restrict-qualified pointers. */
|
/* Check for accesses through restrict-qualified pointers. */
|
if (INDIRECT_REF_P (inner))
|
if (INDIRECT_REF_P (inner))
|
{
|
{
|
tree decl = find_base_decl (TREE_OPERAND (inner, 0));
|
tree decl = find_base_decl (TREE_OPERAND (inner, 0));
|
|
|
if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
|
if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
|
{
|
{
|
/* If we haven't computed the actual alias set, do it now. */
|
/* If we haven't computed the actual alias set, do it now. */
|
if (DECL_POINTER_ALIAS_SET (decl) == -2)
|
if (DECL_POINTER_ALIAS_SET (decl) == -2)
|
{
|
{
|
tree pointed_to_type = TREE_TYPE (TREE_TYPE (decl));
|
tree pointed_to_type = TREE_TYPE (TREE_TYPE (decl));
|
|
|
/* No two restricted pointers can point at the same thing.
|
/* No two restricted pointers can point at the same thing.
|
However, a restricted pointer can point at the same thing
|
However, a restricted pointer can point at the same thing
|
as an unrestricted pointer, if that unrestricted pointer
|
as an unrestricted pointer, if that unrestricted pointer
|
is based on the restricted pointer. So, we make the
|
is based on the restricted pointer. So, we make the
|
alias set for the restricted pointer a subset of the
|
alias set for the restricted pointer a subset of the
|
alias set for the type pointed to by the type of the
|
alias set for the type pointed to by the type of the
|
decl. */
|
decl. */
|
HOST_WIDE_INT pointed_to_alias_set
|
HOST_WIDE_INT pointed_to_alias_set
|
= get_alias_set (pointed_to_type);
|
= get_alias_set (pointed_to_type);
|
|
|
if (pointed_to_alias_set == 0)
|
if (pointed_to_alias_set == 0)
|
/* It's not legal to make a subset of alias set zero. */
|
/* It's not legal to make a subset of alias set zero. */
|
DECL_POINTER_ALIAS_SET (decl) = 0;
|
DECL_POINTER_ALIAS_SET (decl) = 0;
|
else if (AGGREGATE_TYPE_P (pointed_to_type))
|
else if (AGGREGATE_TYPE_P (pointed_to_type))
|
/* For an aggregate, we must treat the restricted
|
/* For an aggregate, we must treat the restricted
|
pointer the same as an ordinary pointer. If we
|
pointer the same as an ordinary pointer. If we
|
were to make the type pointed to by the
|
were to make the type pointed to by the
|
restricted pointer a subset of the pointed-to
|
restricted pointer a subset of the pointed-to
|
type, then we would believe that other subsets
|
type, then we would believe that other subsets
|
of the pointed-to type (such as fields of that
|
of the pointed-to type (such as fields of that
|
type) do not conflict with the type pointed to
|
type) do not conflict with the type pointed to
|
by the restricted pointer. */
|
by the restricted pointer. */
|
DECL_POINTER_ALIAS_SET (decl)
|
DECL_POINTER_ALIAS_SET (decl)
|
= pointed_to_alias_set;
|
= pointed_to_alias_set;
|
else
|
else
|
{
|
{
|
DECL_POINTER_ALIAS_SET (decl) = new_alias_set ();
|
DECL_POINTER_ALIAS_SET (decl) = new_alias_set ();
|
record_alias_subset (pointed_to_alias_set,
|
record_alias_subset (pointed_to_alias_set,
|
DECL_POINTER_ALIAS_SET (decl));
|
DECL_POINTER_ALIAS_SET (decl));
|
}
|
}
|
}
|
}
|
|
|
/* We use the alias set indicated in the declaration. */
|
/* We use the alias set indicated in the declaration. */
|
return DECL_POINTER_ALIAS_SET (decl);
|
return DECL_POINTER_ALIAS_SET (decl);
|
}
|
}
|
|
|
/* If we have an INDIRECT_REF via a void pointer, we don't
|
/* If we have an INDIRECT_REF via a void pointer, we don't
|
know anything about what that might alias. Likewise if the
|
know anything about what that might alias. Likewise if the
|
pointer is marked that way. */
|
pointer is marked that way. */
|
else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE
|
else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE
|
|| (TYPE_REF_CAN_ALIAS_ALL
|
|| (TYPE_REF_CAN_ALIAS_ALL
|
(TREE_TYPE (TREE_OPERAND (inner, 0)))))
|
(TREE_TYPE (TREE_OPERAND (inner, 0)))))
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Otherwise, pick up the outermost object that we could have a pointer
|
/* Otherwise, pick up the outermost object that we could have a pointer
|
to, processing conversions as above. */
|
to, processing conversions as above. */
|
while (component_uses_parent_alias_set (t))
|
while (component_uses_parent_alias_set (t))
|
{
|
{
|
t = TREE_OPERAND (t, 0);
|
t = TREE_OPERAND (t, 0);
|
STRIP_NOPS (t);
|
STRIP_NOPS (t);
|
}
|
}
|
|
|
/* If we've already determined the alias set for a decl, just return
|
/* If we've already determined the alias set for a decl, just return
|
it. This is necessary for C++ anonymous unions, whose component
|
it. This is necessary for C++ anonymous unions, whose component
|
variables don't look like union members (boo!). */
|
variables don't look like union members (boo!). */
|
if (TREE_CODE (t) == VAR_DECL
|
if (TREE_CODE (t) == VAR_DECL
|
&& DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t)))
|
&& DECL_RTL_SET_P (t) && MEM_P (DECL_RTL (t)))
|
return MEM_ALIAS_SET (DECL_RTL (t));
|
return MEM_ALIAS_SET (DECL_RTL (t));
|
|
|
/* Now all we care about is the type. */
|
/* Now all we care about is the type. */
|
t = TREE_TYPE (t);
|
t = TREE_TYPE (t);
|
}
|
}
|
|
|
/* Variant qualifiers don't affect the alias set, so get the main
|
/* Variant qualifiers don't affect the alias set, so get the main
|
variant. If this is a type with a known alias set, return it. */
|
variant. If this is a type with a known alias set, return it. */
|
t = TYPE_MAIN_VARIANT (t);
|
t = TYPE_MAIN_VARIANT (t);
|
if (TYPE_ALIAS_SET_KNOWN_P (t))
|
if (TYPE_ALIAS_SET_KNOWN_P (t))
|
return TYPE_ALIAS_SET (t);
|
return TYPE_ALIAS_SET (t);
|
|
|
/* See if the language has special handling for this type. */
|
/* See if the language has special handling for this type. */
|
set = lang_hooks.get_alias_set (t);
|
set = lang_hooks.get_alias_set (t);
|
if (set != -1)
|
if (set != -1)
|
return set;
|
return set;
|
|
|
/* There are no objects of FUNCTION_TYPE, so there's no point in
|
/* There are no objects of FUNCTION_TYPE, so there's no point in
|
using up an alias set for them. (There are, of course, pointers
|
using up an alias set for them. (There are, of course, pointers
|
and references to functions, but that's different.) */
|
and references to functions, but that's different.) */
|
else if (TREE_CODE (t) == FUNCTION_TYPE)
|
else if (TREE_CODE (t) == FUNCTION_TYPE)
|
set = 0;
|
set = 0;
|
|
|
/* Unless the language specifies otherwise, let vector types alias
|
/* Unless the language specifies otherwise, let vector types alias
|
their components. This avoids some nasty type punning issues in
|
their components. This avoids some nasty type punning issues in
|
normal usage. And indeed lets vectors be treated more like an
|
normal usage. And indeed lets vectors be treated more like an
|
array slice. */
|
array slice. */
|
else if (TREE_CODE (t) == VECTOR_TYPE)
|
else if (TREE_CODE (t) == VECTOR_TYPE)
|
set = get_alias_set (TREE_TYPE (t));
|
set = get_alias_set (TREE_TYPE (t));
|
|
|
else
|
else
|
/* Otherwise make a new alias set for this type. */
|
/* Otherwise make a new alias set for this type. */
|
set = new_alias_set ();
|
set = new_alias_set ();
|
|
|
TYPE_ALIAS_SET (t) = set;
|
TYPE_ALIAS_SET (t) = set;
|
|
|
/* If this is an aggregate type, we must record any component aliasing
|
/* If this is an aggregate type, we must record any component aliasing
|
information. */
|
information. */
|
if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE)
|
if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE)
|
record_component_aliases (t);
|
record_component_aliases (t);
|
|
|
return set;
|
return set;
|
}
|
}
|
|
|
/* Return a brand-new alias set. */
|
/* Return a brand-new alias set. */
|
|
|
HOST_WIDE_INT
|
HOST_WIDE_INT
|
new_alias_set (void)
|
new_alias_set (void)
|
{
|
{
|
if (flag_strict_aliasing)
|
if (flag_strict_aliasing)
|
{
|
{
|
if (alias_sets == 0)
|
if (alias_sets == 0)
|
VEC_safe_push (alias_set_entry, gc, alias_sets, 0);
|
VEC_safe_push (alias_set_entry, gc, alias_sets, 0);
|
VEC_safe_push (alias_set_entry, gc, alias_sets, 0);
|
VEC_safe_push (alias_set_entry, gc, alias_sets, 0);
|
return VEC_length (alias_set_entry, alias_sets) - 1;
|
return VEC_length (alias_set_entry, alias_sets) - 1;
|
}
|
}
|
else
|
else
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Indicate that things in SUBSET can alias things in SUPERSET, but that
|
/* Indicate that things in SUBSET can alias things in SUPERSET, but that
|
not everything that aliases SUPERSET also aliases SUBSET. For example,
|
not everything that aliases SUPERSET also aliases SUBSET. For example,
|
in C, a store to an `int' can alias a load of a structure containing an
|
in C, a store to an `int' can alias a load of a structure containing an
|
`int', and vice versa. But it can't alias a load of a 'double' member
|
`int', and vice versa. But it can't alias a load of a 'double' member
|
of the same structure. Here, the structure would be the SUPERSET and
|
of the same structure. Here, the structure would be the SUPERSET and
|
`int' the SUBSET. This relationship is also described in the comment at
|
`int' the SUBSET. This relationship is also described in the comment at
|
the beginning of this file.
|
the beginning of this file.
|
|
|
This function should be called only once per SUPERSET/SUBSET pair.
|
This function should be called only once per SUPERSET/SUBSET pair.
|
|
|
It is illegal for SUPERSET to be zero; everything is implicitly a
|
It is illegal for SUPERSET to be zero; everything is implicitly a
|
subset of alias set zero. */
|
subset of alias set zero. */
|
|
|
static void
|
static void
|
record_alias_subset (HOST_WIDE_INT superset, HOST_WIDE_INT subset)
|
record_alias_subset (HOST_WIDE_INT superset, HOST_WIDE_INT subset)
|
{
|
{
|
alias_set_entry superset_entry;
|
alias_set_entry superset_entry;
|
alias_set_entry subset_entry;
|
alias_set_entry subset_entry;
|
|
|
/* It is possible in complex type situations for both sets to be the same,
|
/* It is possible in complex type situations for both sets to be the same,
|
in which case we can ignore this operation. */
|
in which case we can ignore this operation. */
|
if (superset == subset)
|
if (superset == subset)
|
return;
|
return;
|
|
|
gcc_assert (superset);
|
gcc_assert (superset);
|
|
|
superset_entry = get_alias_set_entry (superset);
|
superset_entry = get_alias_set_entry (superset);
|
if (superset_entry == 0)
|
if (superset_entry == 0)
|
{
|
{
|
/* Create an entry for the SUPERSET, so that we have a place to
|
/* Create an entry for the SUPERSET, so that we have a place to
|
attach the SUBSET. */
|
attach the SUBSET. */
|
superset_entry = ggc_alloc (sizeof (struct alias_set_entry));
|
superset_entry = ggc_alloc (sizeof (struct alias_set_entry));
|
superset_entry->alias_set = superset;
|
superset_entry->alias_set = superset;
|
superset_entry->children
|
superset_entry->children
|
= splay_tree_new_ggc (splay_tree_compare_ints);
|
= splay_tree_new_ggc (splay_tree_compare_ints);
|
superset_entry->has_zero_child = 0;
|
superset_entry->has_zero_child = 0;
|
VEC_replace (alias_set_entry, alias_sets, superset, superset_entry);
|
VEC_replace (alias_set_entry, alias_sets, superset, superset_entry);
|
}
|
}
|
|
|
if (subset == 0)
|
if (subset == 0)
|
superset_entry->has_zero_child = 1;
|
superset_entry->has_zero_child = 1;
|
else
|
else
|
{
|
{
|
subset_entry = get_alias_set_entry (subset);
|
subset_entry = get_alias_set_entry (subset);
|
/* If there is an entry for the subset, enter all of its children
|
/* If there is an entry for the subset, enter all of its children
|
(if they are not already present) as children of the SUPERSET. */
|
(if they are not already present) as children of the SUPERSET. */
|
if (subset_entry)
|
if (subset_entry)
|
{
|
{
|
if (subset_entry->has_zero_child)
|
if (subset_entry->has_zero_child)
|
superset_entry->has_zero_child = 1;
|
superset_entry->has_zero_child = 1;
|
|
|
splay_tree_foreach (subset_entry->children, insert_subset_children,
|
splay_tree_foreach (subset_entry->children, insert_subset_children,
|
superset_entry->children);
|
superset_entry->children);
|
}
|
}
|
|
|
/* Enter the SUBSET itself as a child of the SUPERSET. */
|
/* Enter the SUBSET itself as a child of the SUPERSET. */
|
splay_tree_insert (superset_entry->children,
|
splay_tree_insert (superset_entry->children,
|
(splay_tree_key) subset, 0);
|
(splay_tree_key) subset, 0);
|
}
|
}
|
}
|
}
|
|
|
/* Record that component types of TYPE, if any, are part of that type for
|
/* Record that component types of TYPE, if any, are part of that type for
|
aliasing purposes. For record types, we only record component types
|
aliasing purposes. For record types, we only record component types
|
for fields that are marked addressable. For array types, we always
|
for fields that are marked addressable. For array types, we always
|
record the component types, so the front end should not call this
|
record the component types, so the front end should not call this
|
function if the individual component aren't addressable. */
|
function if the individual component aren't addressable. */
|
|
|
void
|
void
|
record_component_aliases (tree type)
|
record_component_aliases (tree type)
|
{
|
{
|
HOST_WIDE_INT superset = get_alias_set (type);
|
HOST_WIDE_INT superset = get_alias_set (type);
|
tree field;
|
tree field;
|
|
|
if (superset == 0)
|
if (superset == 0)
|
return;
|
return;
|
|
|
switch (TREE_CODE (type))
|
switch (TREE_CODE (type))
|
{
|
{
|
case ARRAY_TYPE:
|
case ARRAY_TYPE:
|
if (! TYPE_NONALIASED_COMPONENT (type))
|
if (! TYPE_NONALIASED_COMPONENT (type))
|
record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
|
record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
|
break;
|
break;
|
|
|
case RECORD_TYPE:
|
case RECORD_TYPE:
|
case UNION_TYPE:
|
case UNION_TYPE:
|
case QUAL_UNION_TYPE:
|
case QUAL_UNION_TYPE:
|
/* Recursively record aliases for the base classes, if there are any. */
|
/* Recursively record aliases for the base classes, if there are any. */
|
if (TYPE_BINFO (type))
|
if (TYPE_BINFO (type))
|
{
|
{
|
int i;
|
int i;
|
tree binfo, base_binfo;
|
tree binfo, base_binfo;
|
|
|
for (binfo = TYPE_BINFO (type), i = 0;
|
for (binfo = TYPE_BINFO (type), i = 0;
|
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
|
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
|
record_alias_subset (superset,
|
record_alias_subset (superset,
|
get_alias_set (BINFO_TYPE (base_binfo)));
|
get_alias_set (BINFO_TYPE (base_binfo)));
|
}
|
}
|
for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
|
for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
|
if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field))
|
if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field))
|
record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
|
record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
|
break;
|
break;
|
|
|
case COMPLEX_TYPE:
|
case COMPLEX_TYPE:
|
record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
|
record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
|
break;
|
break;
|
|
|
default:
|
default:
|
break;
|
break;
|
}
|
}
|
}
|
}
|
|
|
/* Allocate an alias set for use in storing and reading from the varargs
|
/* Allocate an alias set for use in storing and reading from the varargs
|
spill area. */
|
spill area. */
|
|
|
static GTY(()) HOST_WIDE_INT varargs_set = -1;
|
static GTY(()) HOST_WIDE_INT varargs_set = -1;
|
|
|
HOST_WIDE_INT
|
HOST_WIDE_INT
|
get_varargs_alias_set (void)
|
get_varargs_alias_set (void)
|
{
|
{
|
#if 1
|
#if 1
|
/* We now lower VA_ARG_EXPR, and there's currently no way to attach the
|
/* We now lower VA_ARG_EXPR, and there's currently no way to attach the
|
varargs alias set to an INDIRECT_REF (FIXME!), so we can't
|
varargs alias set to an INDIRECT_REF (FIXME!), so we can't
|
consistently use the varargs alias set for loads from the varargs
|
consistently use the varargs alias set for loads from the varargs
|
area. So don't use it anywhere. */
|
area. So don't use it anywhere. */
|
return 0;
|
return 0;
|
#else
|
#else
|
if (varargs_set == -1)
|
if (varargs_set == -1)
|
varargs_set = new_alias_set ();
|
varargs_set = new_alias_set ();
|
|
|
return varargs_set;
|
return varargs_set;
|
#endif
|
#endif
|
}
|
}
|
|
|
/* Likewise, but used for the fixed portions of the frame, e.g., register
|
/* Likewise, but used for the fixed portions of the frame, e.g., register
|
save areas. */
|
save areas. */
|
|
|
static GTY(()) HOST_WIDE_INT frame_set = -1;
|
static GTY(()) HOST_WIDE_INT frame_set = -1;
|
|
|
HOST_WIDE_INT
|
HOST_WIDE_INT
|
get_frame_alias_set (void)
|
get_frame_alias_set (void)
|
{
|
{
|
if (frame_set == -1)
|
if (frame_set == -1)
|
frame_set = new_alias_set ();
|
frame_set = new_alias_set ();
|
|
|
return frame_set;
|
return frame_set;
|
}
|
}
|
|
|
/* Inside SRC, the source of a SET, find a base address. */
|
/* Inside SRC, the source of a SET, find a base address. */
|
|
|
static rtx
|
static rtx
|
find_base_value (rtx src)
|
find_base_value (rtx src)
|
{
|
{
|
unsigned int regno;
|
unsigned int regno;
|
|
|
switch (GET_CODE (src))
|
switch (GET_CODE (src))
|
{
|
{
|
case SYMBOL_REF:
|
case SYMBOL_REF:
|
case LABEL_REF:
|
case LABEL_REF:
|
return src;
|
return src;
|
|
|
case REG:
|
case REG:
|
regno = REGNO (src);
|
regno = REGNO (src);
|
/* At the start of a function, argument registers have known base
|
/* At the start of a function, argument registers have known base
|
values which may be lost later. Returning an ADDRESS
|
values which may be lost later. Returning an ADDRESS
|
expression here allows optimization based on argument values
|
expression here allows optimization based on argument values
|
even when the argument registers are used for other purposes. */
|
even when the argument registers are used for other purposes. */
|
if (regno < FIRST_PSEUDO_REGISTER && copying_arguments)
|
if (regno < FIRST_PSEUDO_REGISTER && copying_arguments)
|
return new_reg_base_value[regno];
|
return new_reg_base_value[regno];
|
|
|
/* If a pseudo has a known base value, return it. Do not do this
|
/* If a pseudo has a known base value, return it. Do not do this
|
for non-fixed hard regs since it can result in a circular
|
for non-fixed hard regs since it can result in a circular
|
dependency chain for registers which have values at function entry.
|
dependency chain for registers which have values at function entry.
|
|
|
The test above is not sufficient because the scheduler may move
|
The test above is not sufficient because the scheduler may move
|
a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */
|
a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */
|
if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno])
|
if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno])
|
&& regno < VEC_length (rtx, reg_base_value))
|
&& regno < VEC_length (rtx, reg_base_value))
|
{
|
{
|
/* If we're inside init_alias_analysis, use new_reg_base_value
|
/* If we're inside init_alias_analysis, use new_reg_base_value
|
to reduce the number of relaxation iterations. */
|
to reduce the number of relaxation iterations. */
|
if (new_reg_base_value && new_reg_base_value[regno]
|
if (new_reg_base_value && new_reg_base_value[regno]
|
&& REG_N_SETS (regno) == 1)
|
&& REG_N_SETS (regno) == 1)
|
return new_reg_base_value[regno];
|
return new_reg_base_value[regno];
|
|
|
if (VEC_index (rtx, reg_base_value, regno))
|
if (VEC_index (rtx, reg_base_value, regno))
|
return VEC_index (rtx, reg_base_value, regno);
|
return VEC_index (rtx, reg_base_value, regno);
|
}
|
}
|
|
|
return 0;
|
return 0;
|
|
|
case MEM:
|
case MEM:
|
/* Check for an argument passed in memory. Only record in the
|
/* Check for an argument passed in memory. Only record in the
|
copying-arguments block; it is too hard to track changes
|
copying-arguments block; it is too hard to track changes
|
otherwise. */
|
otherwise. */
|
if (copying_arguments
|
if (copying_arguments
|
&& (XEXP (src, 0) == arg_pointer_rtx
|
&& (XEXP (src, 0) == arg_pointer_rtx
|
|| (GET_CODE (XEXP (src, 0)) == PLUS
|
|| (GET_CODE (XEXP (src, 0)) == PLUS
|
&& XEXP (XEXP (src, 0), 0) == arg_pointer_rtx)))
|
&& XEXP (XEXP (src, 0), 0) == arg_pointer_rtx)))
|
return gen_rtx_ADDRESS (VOIDmode, src);
|
return gen_rtx_ADDRESS (VOIDmode, src);
|
return 0;
|
return 0;
|
|
|
case CONST:
|
case CONST:
|
src = XEXP (src, 0);
|
src = XEXP (src, 0);
|
if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS)
|
if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS)
|
break;
|
break;
|
|
|
/* ... fall through ... */
|
/* ... fall through ... */
|
|
|
case PLUS:
|
case PLUS:
|
case MINUS:
|
case MINUS:
|
{
|
{
|
rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1);
|
rtx temp, src_0 = XEXP (src, 0), src_1 = XEXP (src, 1);
|
|
|
/* If either operand is a REG that is a known pointer, then it
|
/* If either operand is a REG that is a known pointer, then it
|
is the base. */
|
is the base. */
|
if (REG_P (src_0) && REG_POINTER (src_0))
|
if (REG_P (src_0) && REG_POINTER (src_0))
|
return find_base_value (src_0);
|
return find_base_value (src_0);
|
if (REG_P (src_1) && REG_POINTER (src_1))
|
if (REG_P (src_1) && REG_POINTER (src_1))
|
return find_base_value (src_1);
|
return find_base_value (src_1);
|
|
|
/* If either operand is a REG, then see if we already have
|
/* If either operand is a REG, then see if we already have
|
a known value for it. */
|
a known value for it. */
|
if (REG_P (src_0))
|
if (REG_P (src_0))
|
{
|
{
|
temp = find_base_value (src_0);
|
temp = find_base_value (src_0);
|
if (temp != 0)
|
if (temp != 0)
|
src_0 = temp;
|
src_0 = temp;
|
}
|
}
|
|
|
if (REG_P (src_1))
|
if (REG_P (src_1))
|
{
|
{
|
temp = find_base_value (src_1);
|
temp = find_base_value (src_1);
|
if (temp!= 0)
|
if (temp!= 0)
|
src_1 = temp;
|
src_1 = temp;
|
}
|
}
|
|
|
/* If either base is named object or a special address
|
/* If either base is named object or a special address
|
(like an argument or stack reference), then use it for the
|
(like an argument or stack reference), then use it for the
|
base term. */
|
base term. */
|
if (src_0 != 0
|
if (src_0 != 0
|
&& (GET_CODE (src_0) == SYMBOL_REF
|
&& (GET_CODE (src_0) == SYMBOL_REF
|
|| GET_CODE (src_0) == LABEL_REF
|
|| GET_CODE (src_0) == LABEL_REF
|
|| (GET_CODE (src_0) == ADDRESS
|
|| (GET_CODE (src_0) == ADDRESS
|
&& GET_MODE (src_0) != VOIDmode)))
|
&& GET_MODE (src_0) != VOIDmode)))
|
return src_0;
|
return src_0;
|
|
|
if (src_1 != 0
|
if (src_1 != 0
|
&& (GET_CODE (src_1) == SYMBOL_REF
|
&& (GET_CODE (src_1) == SYMBOL_REF
|
|| GET_CODE (src_1) == LABEL_REF
|
|| GET_CODE (src_1) == LABEL_REF
|
|| (GET_CODE (src_1) == ADDRESS
|
|| (GET_CODE (src_1) == ADDRESS
|
&& GET_MODE (src_1) != VOIDmode)))
|
&& GET_MODE (src_1) != VOIDmode)))
|
return src_1;
|
return src_1;
|
|
|
/* Guess which operand is the base address:
|
/* Guess which operand is the base address:
|
If either operand is a symbol, then it is the base. If
|
If either operand is a symbol, then it is the base. If
|
either operand is a CONST_INT, then the other is the base. */
|
either operand is a CONST_INT, then the other is the base. */
|
if (GET_CODE (src_1) == CONST_INT || CONSTANT_P (src_0))
|
if (GET_CODE (src_1) == CONST_INT || CONSTANT_P (src_0))
|
return find_base_value (src_0);
|
return find_base_value (src_0);
|
else if (GET_CODE (src_0) == CONST_INT || CONSTANT_P (src_1))
|
else if (GET_CODE (src_0) == CONST_INT || CONSTANT_P (src_1))
|
return find_base_value (src_1);
|
return find_base_value (src_1);
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
case LO_SUM:
|
case LO_SUM:
|
/* The standard form is (lo_sum reg sym) so look only at the
|
/* The standard form is (lo_sum reg sym) so look only at the
|
second operand. */
|
second operand. */
|
return find_base_value (XEXP (src, 1));
|
return find_base_value (XEXP (src, 1));
|
|
|
case AND:
|
case AND:
|
/* If the second operand is constant set the base
|
/* If the second operand is constant set the base
|
address to the first operand. */
|
address to the first operand. */
|
if (GET_CODE (XEXP (src, 1)) == CONST_INT && INTVAL (XEXP (src, 1)) != 0)
|
if (GET_CODE (XEXP (src, 1)) == CONST_INT && INTVAL (XEXP (src, 1)) != 0)
|
return find_base_value (XEXP (src, 0));
|
return find_base_value (XEXP (src, 0));
|
return 0;
|
return 0;
|
|
|
case TRUNCATE:
|
case TRUNCATE:
|
if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode))
|
if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode))
|
break;
|
break;
|
/* Fall through. */
|
/* Fall through. */
|
case HIGH:
|
case HIGH:
|
case PRE_INC:
|
case PRE_INC:
|
case PRE_DEC:
|
case PRE_DEC:
|
case POST_INC:
|
case POST_INC:
|
case POST_DEC:
|
case POST_DEC:
|
case PRE_MODIFY:
|
case PRE_MODIFY:
|
case POST_MODIFY:
|
case POST_MODIFY:
|
return find_base_value (XEXP (src, 0));
|
return find_base_value (XEXP (src, 0));
|
|
|
case ZERO_EXTEND:
|
case ZERO_EXTEND:
|
case SIGN_EXTEND: /* used for NT/Alpha pointers */
|
case SIGN_EXTEND: /* used for NT/Alpha pointers */
|
{
|
{
|
rtx temp = find_base_value (XEXP (src, 0));
|
rtx temp = find_base_value (XEXP (src, 0));
|
|
|
if (temp != 0 && CONSTANT_P (temp))
|
if (temp != 0 && CONSTANT_P (temp))
|
temp = convert_memory_address (Pmode, temp);
|
temp = convert_memory_address (Pmode, temp);
|
|
|
return temp;
|
return temp;
|
}
|
}
|
|
|
default:
|
default:
|
break;
|
break;
|
}
|
}
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Called from init_alias_analysis indirectly through note_stores. */
|
/* Called from init_alias_analysis indirectly through note_stores. */
|
|
|
/* While scanning insns to find base values, reg_seen[N] is nonzero if
|
/* While scanning insns to find base values, reg_seen[N] is nonzero if
|
register N has been set in this function. */
|
register N has been set in this function. */
|
static char *reg_seen;
|
static char *reg_seen;
|
|
|
/* Addresses which are known not to alias anything else are identified
|
/* Addresses which are known not to alias anything else are identified
|
by a unique integer. */
|
by a unique integer. */
|
static int unique_id;
|
static int unique_id;
|
|
|
static void
|
static void
|
record_set (rtx dest, rtx set, void *data ATTRIBUTE_UNUSED)
|
record_set (rtx dest, rtx set, void *data ATTRIBUTE_UNUSED)
|
{
|
{
|
unsigned regno;
|
unsigned regno;
|
rtx src;
|
rtx src;
|
int n;
|
int n;
|
|
|
if (!REG_P (dest))
|
if (!REG_P (dest))
|
return;
|
return;
|
|
|
regno = REGNO (dest);
|
regno = REGNO (dest);
|
|
|
gcc_assert (regno < VEC_length (rtx, reg_base_value));
|
gcc_assert (regno < VEC_length (rtx, reg_base_value));
|
|
|
/* If this spans multiple hard registers, then we must indicate that every
|
/* If this spans multiple hard registers, then we must indicate that every
|
register has an unusable value. */
|
register has an unusable value. */
|
if (regno < FIRST_PSEUDO_REGISTER)
|
if (regno < FIRST_PSEUDO_REGISTER)
|
n = hard_regno_nregs[regno][GET_MODE (dest)];
|
n = hard_regno_nregs[regno][GET_MODE (dest)];
|
else
|
else
|
n = 1;
|
n = 1;
|
if (n != 1)
|
if (n != 1)
|
{
|
{
|
while (--n >= 0)
|
while (--n >= 0)
|
{
|
{
|
reg_seen[regno + n] = 1;
|
reg_seen[regno + n] = 1;
|
new_reg_base_value[regno + n] = 0;
|
new_reg_base_value[regno + n] = 0;
|
}
|
}
|
return;
|
return;
|
}
|
}
|
|
|
if (set)
|
if (set)
|
{
|
{
|
/* A CLOBBER wipes out any old value but does not prevent a previously
|
/* A CLOBBER wipes out any old value but does not prevent a previously
|
unset register from acquiring a base address (i.e. reg_seen is not
|
unset register from acquiring a base address (i.e. reg_seen is not
|
set). */
|
set). */
|
if (GET_CODE (set) == CLOBBER)
|
if (GET_CODE (set) == CLOBBER)
|
{
|
{
|
new_reg_base_value[regno] = 0;
|
new_reg_base_value[regno] = 0;
|
return;
|
return;
|
}
|
}
|
src = SET_SRC (set);
|
src = SET_SRC (set);
|
}
|
}
|
else
|
else
|
{
|
{
|
if (reg_seen[regno])
|
if (reg_seen[regno])
|
{
|
{
|
new_reg_base_value[regno] = 0;
|
new_reg_base_value[regno] = 0;
|
return;
|
return;
|
}
|
}
|
reg_seen[regno] = 1;
|
reg_seen[regno] = 1;
|
new_reg_base_value[regno] = gen_rtx_ADDRESS (Pmode,
|
new_reg_base_value[regno] = gen_rtx_ADDRESS (Pmode,
|
GEN_INT (unique_id++));
|
GEN_INT (unique_id++));
|
return;
|
return;
|
}
|
}
|
|
|
/* If this is not the first set of REGNO, see whether the new value
|
/* If this is not the first set of REGNO, see whether the new value
|
is related to the old one. There are two cases of interest:
|
is related to the old one. There are two cases of interest:
|
|
|
(1) The register might be assigned an entirely new value
|
(1) The register might be assigned an entirely new value
|
that has the same base term as the original set.
|
that has the same base term as the original set.
|
|
|
(2) The set might be a simple self-modification that
|
(2) The set might be a simple self-modification that
|
cannot change REGNO's base value.
|
cannot change REGNO's base value.
|
|
|
If neither case holds, reject the original base value as invalid.
|
If neither case holds, reject the original base value as invalid.
|
Note that the following situation is not detected:
|
Note that the following situation is not detected:
|
|
|
extern int x, y; int *p = &x; p += (&y-&x);
|
extern int x, y; int *p = &x; p += (&y-&x);
|
|
|
ANSI C does not allow computing the difference of addresses
|
ANSI C does not allow computing the difference of addresses
|
of distinct top level objects. */
|
of distinct top level objects. */
|
if (new_reg_base_value[regno] != 0
|
if (new_reg_base_value[regno] != 0
|
&& find_base_value (src) != new_reg_base_value[regno])
|
&& find_base_value (src) != new_reg_base_value[regno])
|
switch (GET_CODE (src))
|
switch (GET_CODE (src))
|
{
|
{
|
case LO_SUM:
|
case LO_SUM:
|
case MINUS:
|
case MINUS:
|
if (XEXP (src, 0) != dest && XEXP (src, 1) != dest)
|
if (XEXP (src, 0) != dest && XEXP (src, 1) != dest)
|
new_reg_base_value[regno] = 0;
|
new_reg_base_value[regno] = 0;
|
break;
|
break;
|
case PLUS:
|
case PLUS:
|
/* If the value we add in the PLUS is also a valid base value,
|
/* If the value we add in the PLUS is also a valid base value,
|
this might be the actual base value, and the original value
|
this might be the actual base value, and the original value
|
an index. */
|
an index. */
|
{
|
{
|
rtx other = NULL_RTX;
|
rtx other = NULL_RTX;
|
|
|
if (XEXP (src, 0) == dest)
|
if (XEXP (src, 0) == dest)
|
other = XEXP (src, 1);
|
other = XEXP (src, 1);
|
else if (XEXP (src, 1) == dest)
|
else if (XEXP (src, 1) == dest)
|
other = XEXP (src, 0);
|
other = XEXP (src, 0);
|
|
|
if (! other || find_base_value (other))
|
if (! other || find_base_value (other))
|
new_reg_base_value[regno] = 0;
|
new_reg_base_value[regno] = 0;
|
break;
|
break;
|
}
|
}
|
case AND:
|
case AND:
|
if (XEXP (src, 0) != dest || GET_CODE (XEXP (src, 1)) != CONST_INT)
|
if (XEXP (src, 0) != dest || GET_CODE (XEXP (src, 1)) != CONST_INT)
|
new_reg_base_value[regno] = 0;
|
new_reg_base_value[regno] = 0;
|
break;
|
break;
|
default:
|
default:
|
new_reg_base_value[regno] = 0;
|
new_reg_base_value[regno] = 0;
|
break;
|
break;
|
}
|
}
|
/* If this is the first set of a register, record the value. */
|
/* If this is the first set of a register, record the value. */
|
else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno])
|
else if ((regno >= FIRST_PSEUDO_REGISTER || ! fixed_regs[regno])
|
&& ! reg_seen[regno] && new_reg_base_value[regno] == 0)
|
&& ! reg_seen[regno] && new_reg_base_value[regno] == 0)
|
new_reg_base_value[regno] = find_base_value (src);
|
new_reg_base_value[regno] = find_base_value (src);
|
|
|
reg_seen[regno] = 1;
|
reg_seen[regno] = 1;
|
}
|
}
|
|
|
/* Clear alias info for a register. This is used if an RTL transformation
|
/* Clear alias info for a register. This is used if an RTL transformation
|
changes the value of a register. This is used in flow by AUTO_INC_DEC
|
changes the value of a register. This is used in flow by AUTO_INC_DEC
|
optimizations. We don't need to clear reg_base_value, since flow only
|
optimizations. We don't need to clear reg_base_value, since flow only
|
changes the offset. */
|
changes the offset. */
|
|
|
void
|
void
|
clear_reg_alias_info (rtx reg)
|
clear_reg_alias_info (rtx reg)
|
{
|
{
|
unsigned int regno = REGNO (reg);
|
unsigned int regno = REGNO (reg);
|
|
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
regno -= FIRST_PSEUDO_REGISTER;
|
regno -= FIRST_PSEUDO_REGISTER;
|
if (regno < reg_known_value_size)
|
if (regno < reg_known_value_size)
|
{
|
{
|
reg_known_value[regno] = reg;
|
reg_known_value[regno] = reg;
|
reg_known_equiv_p[regno] = false;
|
reg_known_equiv_p[regno] = false;
|
}
|
}
|
}
|
}
|
}
|
}
|
|
|
/* If a value is known for REGNO, return it. */
|
/* If a value is known for REGNO, return it. */
|
|
|
rtx
|
rtx
|
get_reg_known_value (unsigned int regno)
|
get_reg_known_value (unsigned int regno)
|
{
|
{
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
regno -= FIRST_PSEUDO_REGISTER;
|
regno -= FIRST_PSEUDO_REGISTER;
|
if (regno < reg_known_value_size)
|
if (regno < reg_known_value_size)
|
return reg_known_value[regno];
|
return reg_known_value[regno];
|
}
|
}
|
return NULL;
|
return NULL;
|
}
|
}
|
|
|
/* Set it. */
|
/* Set it. */
|
|
|
static void
|
static void
|
set_reg_known_value (unsigned int regno, rtx val)
|
set_reg_known_value (unsigned int regno, rtx val)
|
{
|
{
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
regno -= FIRST_PSEUDO_REGISTER;
|
regno -= FIRST_PSEUDO_REGISTER;
|
if (regno < reg_known_value_size)
|
if (regno < reg_known_value_size)
|
reg_known_value[regno] = val;
|
reg_known_value[regno] = val;
|
}
|
}
|
}
|
}
|
|
|
/* Similarly for reg_known_equiv_p. */
|
/* Similarly for reg_known_equiv_p. */
|
|
|
bool
|
bool
|
get_reg_known_equiv_p (unsigned int regno)
|
get_reg_known_equiv_p (unsigned int regno)
|
{
|
{
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
regno -= FIRST_PSEUDO_REGISTER;
|
regno -= FIRST_PSEUDO_REGISTER;
|
if (regno < reg_known_value_size)
|
if (regno < reg_known_value_size)
|
return reg_known_equiv_p[regno];
|
return reg_known_equiv_p[regno];
|
}
|
}
|
return false;
|
return false;
|
}
|
}
|
|
|
static void
|
static void
|
set_reg_known_equiv_p (unsigned int regno, bool val)
|
set_reg_known_equiv_p (unsigned int regno, bool val)
|
{
|
{
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
if (regno >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
regno -= FIRST_PSEUDO_REGISTER;
|
regno -= FIRST_PSEUDO_REGISTER;
|
if (regno < reg_known_value_size)
|
if (regno < reg_known_value_size)
|
reg_known_equiv_p[regno] = val;
|
reg_known_equiv_p[regno] = val;
|
}
|
}
|
}
|
}
|
|
|
|
|
/* Returns a canonical version of X, from the point of view alias
|
/* Returns a canonical version of X, from the point of view alias
|
analysis. (For example, if X is a MEM whose address is a register,
|
analysis. (For example, if X is a MEM whose address is a register,
|
and the register has a known value (say a SYMBOL_REF), then a MEM
|
and the register has a known value (say a SYMBOL_REF), then a MEM
|
whose address is the SYMBOL_REF is returned.) */
|
whose address is the SYMBOL_REF is returned.) */
|
|
|
rtx
|
rtx
|
canon_rtx (rtx x)
|
canon_rtx (rtx x)
|
{
|
{
|
/* Recursively look for equivalences. */
|
/* Recursively look for equivalences. */
|
if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER)
|
if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
rtx t = get_reg_known_value (REGNO (x));
|
rtx t = get_reg_known_value (REGNO (x));
|
if (t == x)
|
if (t == x)
|
return x;
|
return x;
|
if (t)
|
if (t)
|
return canon_rtx (t);
|
return canon_rtx (t);
|
}
|
}
|
|
|
if (GET_CODE (x) == PLUS)
|
if (GET_CODE (x) == PLUS)
|
{
|
{
|
rtx x0 = canon_rtx (XEXP (x, 0));
|
rtx x0 = canon_rtx (XEXP (x, 0));
|
rtx x1 = canon_rtx (XEXP (x, 1));
|
rtx x1 = canon_rtx (XEXP (x, 1));
|
|
|
if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1))
|
if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1))
|
{
|
{
|
if (GET_CODE (x0) == CONST_INT)
|
if (GET_CODE (x0) == CONST_INT)
|
return plus_constant (x1, INTVAL (x0));
|
return plus_constant (x1, INTVAL (x0));
|
else if (GET_CODE (x1) == CONST_INT)
|
else if (GET_CODE (x1) == CONST_INT)
|
return plus_constant (x0, INTVAL (x1));
|
return plus_constant (x0, INTVAL (x1));
|
return gen_rtx_PLUS (GET_MODE (x), x0, x1);
|
return gen_rtx_PLUS (GET_MODE (x), x0, x1);
|
}
|
}
|
}
|
}
|
|
|
/* This gives us much better alias analysis when called from
|
/* This gives us much better alias analysis when called from
|
the loop optimizer. Note we want to leave the original
|
the loop optimizer. Note we want to leave the original
|
MEM alone, but need to return the canonicalized MEM with
|
MEM alone, but need to return the canonicalized MEM with
|
all the flags with their original values. */
|
all the flags with their original values. */
|
else if (MEM_P (x))
|
else if (MEM_P (x))
|
x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0)));
|
x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0)));
|
|
|
return x;
|
return x;
|
}
|
}
|
|
|
/* Return 1 if X and Y are identical-looking rtx's.
|
/* Return 1 if X and Y are identical-looking rtx's.
|
Expect that X and Y has been already canonicalized.
|
Expect that X and Y has been already canonicalized.
|
|
|
We use the data in reg_known_value above to see if two registers with
|
We use the data in reg_known_value above to see if two registers with
|
different numbers are, in fact, equivalent. */
|
different numbers are, in fact, equivalent. */
|
|
|
static int
|
static int
|
rtx_equal_for_memref_p (rtx x, rtx y)
|
rtx_equal_for_memref_p (rtx x, rtx y)
|
{
|
{
|
int i;
|
int i;
|
int j;
|
int j;
|
enum rtx_code code;
|
enum rtx_code code;
|
const char *fmt;
|
const char *fmt;
|
|
|
if (x == 0 && y == 0)
|
if (x == 0 && y == 0)
|
return 1;
|
return 1;
|
if (x == 0 || y == 0)
|
if (x == 0 || y == 0)
|
return 0;
|
return 0;
|
|
|
if (x == y)
|
if (x == y)
|
return 1;
|
return 1;
|
|
|
code = GET_CODE (x);
|
code = GET_CODE (x);
|
/* Rtx's of different codes cannot be equal. */
|
/* Rtx's of different codes cannot be equal. */
|
if (code != GET_CODE (y))
|
if (code != GET_CODE (y))
|
return 0;
|
return 0;
|
|
|
/* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
|
/* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.
|
(REG:SI x) and (REG:HI x) are NOT equivalent. */
|
(REG:SI x) and (REG:HI x) are NOT equivalent. */
|
|
|
if (GET_MODE (x) != GET_MODE (y))
|
if (GET_MODE (x) != GET_MODE (y))
|
return 0;
|
return 0;
|
|
|
/* Some RTL can be compared without a recursive examination. */
|
/* Some RTL can be compared without a recursive examination. */
|
switch (code)
|
switch (code)
|
{
|
{
|
case REG:
|
case REG:
|
return REGNO (x) == REGNO (y);
|
return REGNO (x) == REGNO (y);
|
|
|
case LABEL_REF:
|
case LABEL_REF:
|
return XEXP (x, 0) == XEXP (y, 0);
|
return XEXP (x, 0) == XEXP (y, 0);
|
|
|
case SYMBOL_REF:
|
case SYMBOL_REF:
|
return XSTR (x, 0) == XSTR (y, 0);
|
return XSTR (x, 0) == XSTR (y, 0);
|
|
|
case VALUE:
|
case VALUE:
|
case CONST_INT:
|
case CONST_INT:
|
case CONST_DOUBLE:
|
case CONST_DOUBLE:
|
/* There's no need to compare the contents of CONST_DOUBLEs or
|
/* There's no need to compare the contents of CONST_DOUBLEs or
|
CONST_INTs because pointer equality is a good enough
|
CONST_INTs because pointer equality is a good enough
|
comparison for these nodes. */
|
comparison for these nodes. */
|
return 0;
|
return 0;
|
|
|
default:
|
default:
|
break;
|
break;
|
}
|
}
|
|
|
/* canon_rtx knows how to handle plus. No need to canonicalize. */
|
/* canon_rtx knows how to handle plus. No need to canonicalize. */
|
if (code == PLUS)
|
if (code == PLUS)
|
return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0))
|
return ((rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0))
|
&& rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1)))
|
&& rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1)))
|
|| (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1))
|
|| (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 1))
|
&& rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0))));
|
&& rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0))));
|
/* For commutative operations, the RTX match if the operand match in any
|
/* For commutative operations, the RTX match if the operand match in any
|
order. Also handle the simple binary and unary cases without a loop. */
|
order. Also handle the simple binary and unary cases without a loop. */
|
if (COMMUTATIVE_P (x))
|
if (COMMUTATIVE_P (x))
|
{
|
{
|
rtx xop0 = canon_rtx (XEXP (x, 0));
|
rtx xop0 = canon_rtx (XEXP (x, 0));
|
rtx yop0 = canon_rtx (XEXP (y, 0));
|
rtx yop0 = canon_rtx (XEXP (y, 0));
|
rtx yop1 = canon_rtx (XEXP (y, 1));
|
rtx yop1 = canon_rtx (XEXP (y, 1));
|
|
|
return ((rtx_equal_for_memref_p (xop0, yop0)
|
return ((rtx_equal_for_memref_p (xop0, yop0)
|
&& rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1))
|
&& rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1))
|
|| (rtx_equal_for_memref_p (xop0, yop1)
|
|| (rtx_equal_for_memref_p (xop0, yop1)
|
&& rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0)));
|
&& rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0)));
|
}
|
}
|
else if (NON_COMMUTATIVE_P (x))
|
else if (NON_COMMUTATIVE_P (x))
|
{
|
{
|
return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)),
|
return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)),
|
canon_rtx (XEXP (y, 0)))
|
canon_rtx (XEXP (y, 0)))
|
&& rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)),
|
&& rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)),
|
canon_rtx (XEXP (y, 1))));
|
canon_rtx (XEXP (y, 1))));
|
}
|
}
|
else if (UNARY_P (x))
|
else if (UNARY_P (x))
|
return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)),
|
return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)),
|
canon_rtx (XEXP (y, 0)));
|
canon_rtx (XEXP (y, 0)));
|
|
|
/* Compare the elements. If any pair of corresponding elements
|
/* Compare the elements. If any pair of corresponding elements
|
fail to match, return 0 for the whole things.
|
fail to match, return 0 for the whole things.
|
|
|
Limit cases to types which actually appear in addresses. */
|
Limit cases to types which actually appear in addresses. */
|
|
|
fmt = GET_RTX_FORMAT (code);
|
fmt = GET_RTX_FORMAT (code);
|
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
{
|
{
|
switch (fmt[i])
|
switch (fmt[i])
|
{
|
{
|
case 'i':
|
case 'i':
|
if (XINT (x, i) != XINT (y, i))
|
if (XINT (x, i) != XINT (y, i))
|
return 0;
|
return 0;
|
break;
|
break;
|
|
|
case 'E':
|
case 'E':
|
/* Two vectors must have the same length. */
|
/* Two vectors must have the same length. */
|
if (XVECLEN (x, i) != XVECLEN (y, i))
|
if (XVECLEN (x, i) != XVECLEN (y, i))
|
return 0;
|
return 0;
|
|
|
/* And the corresponding elements must match. */
|
/* And the corresponding elements must match. */
|
for (j = 0; j < XVECLEN (x, i); j++)
|
for (j = 0; j < XVECLEN (x, i); j++)
|
if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)),
|
if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)),
|
canon_rtx (XVECEXP (y, i, j))) == 0)
|
canon_rtx (XVECEXP (y, i, j))) == 0)
|
return 0;
|
return 0;
|
break;
|
break;
|
|
|
case 'e':
|
case 'e':
|
if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)),
|
if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)),
|
canon_rtx (XEXP (y, i))) == 0)
|
canon_rtx (XEXP (y, i))) == 0)
|
return 0;
|
return 0;
|
break;
|
break;
|
|
|
/* This can happen for asm operands. */
|
/* This can happen for asm operands. */
|
case 's':
|
case 's':
|
if (strcmp (XSTR (x, i), XSTR (y, i)))
|
if (strcmp (XSTR (x, i), XSTR (y, i)))
|
return 0;
|
return 0;
|
break;
|
break;
|
|
|
/* This can happen for an asm which clobbers memory. */
|
/* This can happen for an asm which clobbers memory. */
|
case '0':
|
case '0':
|
break;
|
break;
|
|
|
/* It is believed that rtx's at this level will never
|
/* It is believed that rtx's at this level will never
|
contain anything but integers and other rtx's,
|
contain anything but integers and other rtx's,
|
except for within LABEL_REFs and SYMBOL_REFs. */
|
except for within LABEL_REFs and SYMBOL_REFs. */
|
default:
|
default:
|
gcc_unreachable ();
|
gcc_unreachable ();
|
}
|
}
|
}
|
}
|
return 1;
|
return 1;
|
}
|
}
|
|
|
/* Given an rtx X, find a SYMBOL_REF or LABEL_REF within
|
/* Given an rtx X, find a SYMBOL_REF or LABEL_REF within
|
X and return it, or return 0 if none found. */
|
X and return it, or return 0 if none found. */
|
|
|
static rtx
|
static rtx
|
find_symbolic_term (rtx x)
|
find_symbolic_term (rtx x)
|
{
|
{
|
int i;
|
int i;
|
enum rtx_code code;
|
enum rtx_code code;
|
const char *fmt;
|
const char *fmt;
|
|
|
code = GET_CODE (x);
|
code = GET_CODE (x);
|
if (code == SYMBOL_REF || code == LABEL_REF)
|
if (code == SYMBOL_REF || code == LABEL_REF)
|
return x;
|
return x;
|
if (OBJECT_P (x))
|
if (OBJECT_P (x))
|
return 0;
|
return 0;
|
|
|
fmt = GET_RTX_FORMAT (code);
|
fmt = GET_RTX_FORMAT (code);
|
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
|
{
|
{
|
rtx t;
|
rtx t;
|
|
|
if (fmt[i] == 'e')
|
if (fmt[i] == 'e')
|
{
|
{
|
t = find_symbolic_term (XEXP (x, i));
|
t = find_symbolic_term (XEXP (x, i));
|
if (t != 0)
|
if (t != 0)
|
return t;
|
return t;
|
}
|
}
|
else if (fmt[i] == 'E')
|
else if (fmt[i] == 'E')
|
break;
|
break;
|
}
|
}
|
return 0;
|
return 0;
|
}
|
}
|
|
|
rtx
|
rtx
|
find_base_term (rtx x)
|
find_base_term (rtx x)
|
{
|
{
|
cselib_val *val;
|
cselib_val *val;
|
struct elt_loc_list *l;
|
struct elt_loc_list *l;
|
|
|
#if defined (FIND_BASE_TERM)
|
#if defined (FIND_BASE_TERM)
|
/* Try machine-dependent ways to find the base term. */
|
/* Try machine-dependent ways to find the base term. */
|
x = FIND_BASE_TERM (x);
|
x = FIND_BASE_TERM (x);
|
#endif
|
#endif
|
|
|
switch (GET_CODE (x))
|
switch (GET_CODE (x))
|
{
|
{
|
case REG:
|
case REG:
|
return REG_BASE_VALUE (x);
|
return REG_BASE_VALUE (x);
|
|
|
case TRUNCATE:
|
case TRUNCATE:
|
if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode))
|
if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode))
|
return 0;
|
return 0;
|
/* Fall through. */
|
/* Fall through. */
|
case HIGH:
|
case HIGH:
|
case PRE_INC:
|
case PRE_INC:
|
case PRE_DEC:
|
case PRE_DEC:
|
case POST_INC:
|
case POST_INC:
|
case POST_DEC:
|
case POST_DEC:
|
case PRE_MODIFY:
|
case PRE_MODIFY:
|
case POST_MODIFY:
|
case POST_MODIFY:
|
return find_base_term (XEXP (x, 0));
|
return find_base_term (XEXP (x, 0));
|
|
|
case ZERO_EXTEND:
|
case ZERO_EXTEND:
|
case SIGN_EXTEND: /* Used for Alpha/NT pointers */
|
case SIGN_EXTEND: /* Used for Alpha/NT pointers */
|
{
|
{
|
rtx temp = find_base_term (XEXP (x, 0));
|
rtx temp = find_base_term (XEXP (x, 0));
|
|
|
if (temp != 0 && CONSTANT_P (temp))
|
if (temp != 0 && CONSTANT_P (temp))
|
temp = convert_memory_address (Pmode, temp);
|
temp = convert_memory_address (Pmode, temp);
|
|
|
return temp;
|
return temp;
|
}
|
}
|
|
|
case VALUE:
|
case VALUE:
|
val = CSELIB_VAL_PTR (x);
|
val = CSELIB_VAL_PTR (x);
|
if (!val)
|
if (!val)
|
return 0;
|
return 0;
|
for (l = val->locs; l; l = l->next)
|
for (l = val->locs; l; l = l->next)
|
if ((x = find_base_term (l->loc)) != 0)
|
if ((x = find_base_term (l->loc)) != 0)
|
return x;
|
return x;
|
return 0;
|
return 0;
|
|
|
case CONST:
|
case CONST:
|
x = XEXP (x, 0);
|
x = XEXP (x, 0);
|
if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS)
|
if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS)
|
return 0;
|
return 0;
|
/* Fall through. */
|
/* Fall through. */
|
case LO_SUM:
|
case LO_SUM:
|
case PLUS:
|
case PLUS:
|
case MINUS:
|
case MINUS:
|
{
|
{
|
rtx tmp1 = XEXP (x, 0);
|
rtx tmp1 = XEXP (x, 0);
|
rtx tmp2 = XEXP (x, 1);
|
rtx tmp2 = XEXP (x, 1);
|
|
|
/* This is a little bit tricky since we have to determine which of
|
/* This is a little bit tricky since we have to determine which of
|
the two operands represents the real base address. Otherwise this
|
the two operands represents the real base address. Otherwise this
|
routine may return the index register instead of the base register.
|
routine may return the index register instead of the base register.
|
|
|
That may cause us to believe no aliasing was possible, when in
|
That may cause us to believe no aliasing was possible, when in
|
fact aliasing is possible.
|
fact aliasing is possible.
|
|
|
We use a few simple tests to guess the base register. Additional
|
We use a few simple tests to guess the base register. Additional
|
tests can certainly be added. For example, if one of the operands
|
tests can certainly be added. For example, if one of the operands
|
is a shift or multiply, then it must be the index register and the
|
is a shift or multiply, then it must be the index register and the
|
other operand is the base register. */
|
other operand is the base register. */
|
|
|
if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2))
|
if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2))
|
return find_base_term (tmp2);
|
return find_base_term (tmp2);
|
|
|
/* If either operand is known to be a pointer, then use it
|
/* If either operand is known to be a pointer, then use it
|
to determine the base term. */
|
to determine the base term. */
|
if (REG_P (tmp1) && REG_POINTER (tmp1))
|
if (REG_P (tmp1) && REG_POINTER (tmp1))
|
return find_base_term (tmp1);
|
return find_base_term (tmp1);
|
|
|
if (REG_P (tmp2) && REG_POINTER (tmp2))
|
if (REG_P (tmp2) && REG_POINTER (tmp2))
|
return find_base_term (tmp2);
|
return find_base_term (tmp2);
|
|
|
/* Neither operand was known to be a pointer. Go ahead and find the
|
/* Neither operand was known to be a pointer. Go ahead and find the
|
base term for both operands. */
|
base term for both operands. */
|
tmp1 = find_base_term (tmp1);
|
tmp1 = find_base_term (tmp1);
|
tmp2 = find_base_term (tmp2);
|
tmp2 = find_base_term (tmp2);
|
|
|
/* If either base term is named object or a special address
|
/* If either base term is named object or a special address
|
(like an argument or stack reference), then use it for the
|
(like an argument or stack reference), then use it for the
|
base term. */
|
base term. */
|
if (tmp1 != 0
|
if (tmp1 != 0
|
&& (GET_CODE (tmp1) == SYMBOL_REF
|
&& (GET_CODE (tmp1) == SYMBOL_REF
|
|| GET_CODE (tmp1) == LABEL_REF
|
|| GET_CODE (tmp1) == LABEL_REF
|
|| (GET_CODE (tmp1) == ADDRESS
|
|| (GET_CODE (tmp1) == ADDRESS
|
&& GET_MODE (tmp1) != VOIDmode)))
|
&& GET_MODE (tmp1) != VOIDmode)))
|
return tmp1;
|
return tmp1;
|
|
|
if (tmp2 != 0
|
if (tmp2 != 0
|
&& (GET_CODE (tmp2) == SYMBOL_REF
|
&& (GET_CODE (tmp2) == SYMBOL_REF
|
|| GET_CODE (tmp2) == LABEL_REF
|
|| GET_CODE (tmp2) == LABEL_REF
|
|| (GET_CODE (tmp2) == ADDRESS
|
|| (GET_CODE (tmp2) == ADDRESS
|
&& GET_MODE (tmp2) != VOIDmode)))
|
&& GET_MODE (tmp2) != VOIDmode)))
|
return tmp2;
|
return tmp2;
|
|
|
/* We could not determine which of the two operands was the
|
/* We could not determine which of the two operands was the
|
base register and which was the index. So we can determine
|
base register and which was the index. So we can determine
|
nothing from the base alias check. */
|
nothing from the base alias check. */
|
return 0;
|
return 0;
|
}
|
}
|
|
|
case AND:
|
case AND:
|
if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) != 0)
|
if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) != 0)
|
return find_base_term (XEXP (x, 0));
|
return find_base_term (XEXP (x, 0));
|
return 0;
|
return 0;
|
|
|
case SYMBOL_REF:
|
case SYMBOL_REF:
|
case LABEL_REF:
|
case LABEL_REF:
|
return x;
|
return x;
|
|
|
default:
|
default:
|
return 0;
|
return 0;
|
}
|
}
|
}
|
}
|
|
|
/* Return 0 if the addresses X and Y are known to point to different
|
/* Return 0 if the addresses X and Y are known to point to different
|
objects, 1 if they might be pointers to the same object. */
|
objects, 1 if they might be pointers to the same object. */
|
|
|
static int
|
static int
|
base_alias_check (rtx x, rtx y, enum machine_mode x_mode,
|
base_alias_check (rtx x, rtx y, enum machine_mode x_mode,
|
enum machine_mode y_mode)
|
enum machine_mode y_mode)
|
{
|
{
|
rtx x_base = find_base_term (x);
|
rtx x_base = find_base_term (x);
|
rtx y_base = find_base_term (y);
|
rtx y_base = find_base_term (y);
|
|
|
/* If the address itself has no known base see if a known equivalent
|
/* If the address itself has no known base see if a known equivalent
|
value has one. If either address still has no known base, nothing
|
value has one. If either address still has no known base, nothing
|
is known about aliasing. */
|
is known about aliasing. */
|
if (x_base == 0)
|
if (x_base == 0)
|
{
|
{
|
rtx x_c;
|
rtx x_c;
|
|
|
if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x)
|
if (! flag_expensive_optimizations || (x_c = canon_rtx (x)) == x)
|
return 1;
|
return 1;
|
|
|
x_base = find_base_term (x_c);
|
x_base = find_base_term (x_c);
|
if (x_base == 0)
|
if (x_base == 0)
|
return 1;
|
return 1;
|
}
|
}
|
|
|
if (y_base == 0)
|
if (y_base == 0)
|
{
|
{
|
rtx y_c;
|
rtx y_c;
|
if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y)
|
if (! flag_expensive_optimizations || (y_c = canon_rtx (y)) == y)
|
return 1;
|
return 1;
|
|
|
y_base = find_base_term (y_c);
|
y_base = find_base_term (y_c);
|
if (y_base == 0)
|
if (y_base == 0)
|
return 1;
|
return 1;
|
}
|
}
|
|
|
/* If the base addresses are equal nothing is known about aliasing. */
|
/* If the base addresses are equal nothing is known about aliasing. */
|
if (rtx_equal_p (x_base, y_base))
|
if (rtx_equal_p (x_base, y_base))
|
return 1;
|
return 1;
|
|
|
/* The base addresses of the read and write are different expressions.
|
/* The base addresses of the read and write are different expressions.
|
If they are both symbols and they are not accessed via AND, there is
|
If they are both symbols and they are not accessed via AND, there is
|
no conflict. We can bring knowledge of object alignment into play
|
no conflict. We can bring knowledge of object alignment into play
|
here. For example, on alpha, "char a, b;" can alias one another,
|
here. For example, on alpha, "char a, b;" can alias one another,
|
though "char a; long b;" cannot. */
|
though "char a; long b;" cannot. */
|
if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS)
|
if (GET_CODE (x_base) != ADDRESS && GET_CODE (y_base) != ADDRESS)
|
{
|
{
|
if (GET_CODE (x) == AND && GET_CODE (y) == AND)
|
if (GET_CODE (x) == AND && GET_CODE (y) == AND)
|
return 1;
|
return 1;
|
if (GET_CODE (x) == AND
|
if (GET_CODE (x) == AND
|
&& (GET_CODE (XEXP (x, 1)) != CONST_INT
|
&& (GET_CODE (XEXP (x, 1)) != CONST_INT
|
|| (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1))))
|
|| (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1))))
|
return 1;
|
return 1;
|
if (GET_CODE (y) == AND
|
if (GET_CODE (y) == AND
|
&& (GET_CODE (XEXP (y, 1)) != CONST_INT
|
&& (GET_CODE (XEXP (y, 1)) != CONST_INT
|
|| (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1))))
|
|| (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1))))
|
return 1;
|
return 1;
|
/* Differing symbols never alias. */
|
/* Differing symbols never alias. */
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* If one address is a stack reference there can be no alias:
|
/* If one address is a stack reference there can be no alias:
|
stack references using different base registers do not alias,
|
stack references using different base registers do not alias,
|
a stack reference can not alias a parameter, and a stack reference
|
a stack reference can not alias a parameter, and a stack reference
|
can not alias a global. */
|
can not alias a global. */
|
if ((GET_CODE (x_base) == ADDRESS && GET_MODE (x_base) == Pmode)
|
if ((GET_CODE (x_base) == ADDRESS && GET_MODE (x_base) == Pmode)
|
|| (GET_CODE (y_base) == ADDRESS && GET_MODE (y_base) == Pmode))
|
|| (GET_CODE (y_base) == ADDRESS && GET_MODE (y_base) == Pmode))
|
return 0;
|
return 0;
|
|
|
if (! flag_argument_noalias)
|
if (! flag_argument_noalias)
|
return 1;
|
return 1;
|
|
|
if (flag_argument_noalias > 1)
|
if (flag_argument_noalias > 1)
|
return 0;
|
return 0;
|
|
|
/* Weak noalias assertion (arguments are distinct, but may match globals). */
|
/* Weak noalias assertion (arguments are distinct, but may match globals). */
|
return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode);
|
return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode);
|
}
|
}
|
|
|
/* Convert the address X into something we can use. This is done by returning
|
/* Convert the address X into something we can use. This is done by returning
|
it unchanged unless it is a value; in the latter case we call cselib to get
|
it unchanged unless it is a value; in the latter case we call cselib to get
|
a more useful rtx. */
|
a more useful rtx. */
|
|
|
rtx
|
rtx
|
get_addr (rtx x)
|
get_addr (rtx x)
|
{
|
{
|
cselib_val *v;
|
cselib_val *v;
|
struct elt_loc_list *l;
|
struct elt_loc_list *l;
|
|
|
if (GET_CODE (x) != VALUE)
|
if (GET_CODE (x) != VALUE)
|
return x;
|
return x;
|
v = CSELIB_VAL_PTR (x);
|
v = CSELIB_VAL_PTR (x);
|
if (v)
|
if (v)
|
{
|
{
|
for (l = v->locs; l; l = l->next)
|
for (l = v->locs; l; l = l->next)
|
if (CONSTANT_P (l->loc))
|
if (CONSTANT_P (l->loc))
|
return l->loc;
|
return l->loc;
|
for (l = v->locs; l; l = l->next)
|
for (l = v->locs; l; l = l->next)
|
if (!REG_P (l->loc) && !MEM_P (l->loc))
|
if (!REG_P (l->loc) && !MEM_P (l->loc))
|
return l->loc;
|
return l->loc;
|
if (v->locs)
|
if (v->locs)
|
return v->locs->loc;
|
return v->locs->loc;
|
}
|
}
|
return x;
|
return x;
|
}
|
}
|
|
|
/* Return the address of the (N_REFS + 1)th memory reference to ADDR
|
/* Return the address of the (N_REFS + 1)th memory reference to ADDR
|
where SIZE is the size in bytes of the memory reference. If ADDR
|
where SIZE is the size in bytes of the memory reference. If ADDR
|
is not modified by the memory reference then ADDR is returned. */
|
is not modified by the memory reference then ADDR is returned. */
|
|
|
static rtx
|
static rtx
|
addr_side_effect_eval (rtx addr, int size, int n_refs)
|
addr_side_effect_eval (rtx addr, int size, int n_refs)
|
{
|
{
|
int offset = 0;
|
int offset = 0;
|
|
|
switch (GET_CODE (addr))
|
switch (GET_CODE (addr))
|
{
|
{
|
case PRE_INC:
|
case PRE_INC:
|
offset = (n_refs + 1) * size;
|
offset = (n_refs + 1) * size;
|
break;
|
break;
|
case PRE_DEC:
|
case PRE_DEC:
|
offset = -(n_refs + 1) * size;
|
offset = -(n_refs + 1) * size;
|
break;
|
break;
|
case POST_INC:
|
case POST_INC:
|
offset = n_refs * size;
|
offset = n_refs * size;
|
break;
|
break;
|
case POST_DEC:
|
case POST_DEC:
|
offset = -n_refs * size;
|
offset = -n_refs * size;
|
break;
|
break;
|
|
|
default:
|
default:
|
return addr;
|
return addr;
|
}
|
}
|
|
|
if (offset)
|
if (offset)
|
addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0),
|
addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0),
|
GEN_INT (offset));
|
GEN_INT (offset));
|
else
|
else
|
addr = XEXP (addr, 0);
|
addr = XEXP (addr, 0);
|
addr = canon_rtx (addr);
|
addr = canon_rtx (addr);
|
|
|
return addr;
|
return addr;
|
}
|
}
|
|
|
/* Return nonzero if X and Y (memory addresses) could reference the
|
/* Return nonzero if X and Y (memory addresses) could reference the
|
same location in memory. C is an offset accumulator. When
|
same location in memory. C is an offset accumulator. When
|
C is nonzero, we are testing aliases between X and Y + C.
|
C is nonzero, we are testing aliases between X and Y + C.
|
XSIZE is the size in bytes of the X reference,
|
XSIZE is the size in bytes of the X reference,
|
similarly YSIZE is the size in bytes for Y.
|
similarly YSIZE is the size in bytes for Y.
|
Expect that canon_rtx has been already called for X and Y.
|
Expect that canon_rtx has been already called for X and Y.
|
|
|
If XSIZE or YSIZE is zero, we do not know the amount of memory being
|
If XSIZE or YSIZE is zero, we do not know the amount of memory being
|
referenced (the reference was BLKmode), so make the most pessimistic
|
referenced (the reference was BLKmode), so make the most pessimistic
|
assumptions.
|
assumptions.
|
|
|
If XSIZE or YSIZE is negative, we may access memory outside the object
|
If XSIZE or YSIZE is negative, we may access memory outside the object
|
being referenced as a side effect. This can happen when using AND to
|
being referenced as a side effect. This can happen when using AND to
|
align memory references, as is done on the Alpha.
|
align memory references, as is done on the Alpha.
|
|
|
Nice to notice that varying addresses cannot conflict with fp if no
|
Nice to notice that varying addresses cannot conflict with fp if no
|
local variables had their addresses taken, but that's too hard now. */
|
local variables had their addresses taken, but that's too hard now. */
|
|
|
static int
|
static int
|
memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
|
memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
|
{
|
{
|
if (GET_CODE (x) == VALUE)
|
if (GET_CODE (x) == VALUE)
|
x = get_addr (x);
|
x = get_addr (x);
|
if (GET_CODE (y) == VALUE)
|
if (GET_CODE (y) == VALUE)
|
y = get_addr (y);
|
y = get_addr (y);
|
if (GET_CODE (x) == HIGH)
|
if (GET_CODE (x) == HIGH)
|
x = XEXP (x, 0);
|
x = XEXP (x, 0);
|
else if (GET_CODE (x) == LO_SUM)
|
else if (GET_CODE (x) == LO_SUM)
|
x = XEXP (x, 1);
|
x = XEXP (x, 1);
|
else
|
else
|
x = addr_side_effect_eval (x, xsize, 0);
|
x = addr_side_effect_eval (x, xsize, 0);
|
if (GET_CODE (y) == HIGH)
|
if (GET_CODE (y) == HIGH)
|
y = XEXP (y, 0);
|
y = XEXP (y, 0);
|
else if (GET_CODE (y) == LO_SUM)
|
else if (GET_CODE (y) == LO_SUM)
|
y = XEXP (y, 1);
|
y = XEXP (y, 1);
|
else
|
else
|
y = addr_side_effect_eval (y, ysize, 0);
|
y = addr_side_effect_eval (y, ysize, 0);
|
|
|
if (rtx_equal_for_memref_p (x, y))
|
if (rtx_equal_for_memref_p (x, y))
|
{
|
{
|
if (xsize <= 0 || ysize <= 0)
|
if (xsize <= 0 || ysize <= 0)
|
return 1;
|
return 1;
|
if (c >= 0 && xsize > c)
|
if (c >= 0 && xsize > c)
|
return 1;
|
return 1;
|
if (c < 0 && ysize+c > 0)
|
if (c < 0 && ysize+c > 0)
|
return 1;
|
return 1;
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* This code used to check for conflicts involving stack references and
|
/* This code used to check for conflicts involving stack references and
|
globals but the base address alias code now handles these cases. */
|
globals but the base address alias code now handles these cases. */
|
|
|
if (GET_CODE (x) == PLUS)
|
if (GET_CODE (x) == PLUS)
|
{
|
{
|
/* The fact that X is canonicalized means that this
|
/* The fact that X is canonicalized means that this
|
PLUS rtx is canonicalized. */
|
PLUS rtx is canonicalized. */
|
rtx x0 = XEXP (x, 0);
|
rtx x0 = XEXP (x, 0);
|
rtx x1 = XEXP (x, 1);
|
rtx x1 = XEXP (x, 1);
|
|
|
if (GET_CODE (y) == PLUS)
|
if (GET_CODE (y) == PLUS)
|
{
|
{
|
/* The fact that Y is canonicalized means that this
|
/* The fact that Y is canonicalized means that this
|
PLUS rtx is canonicalized. */
|
PLUS rtx is canonicalized. */
|
rtx y0 = XEXP (y, 0);
|
rtx y0 = XEXP (y, 0);
|
rtx y1 = XEXP (y, 1);
|
rtx y1 = XEXP (y, 1);
|
|
|
if (rtx_equal_for_memref_p (x1, y1))
|
if (rtx_equal_for_memref_p (x1, y1))
|
return memrefs_conflict_p (xsize, x0, ysize, y0, c);
|
return memrefs_conflict_p (xsize, x0, ysize, y0, c);
|
if (rtx_equal_for_memref_p (x0, y0))
|
if (rtx_equal_for_memref_p (x0, y0))
|
return memrefs_conflict_p (xsize, x1, ysize, y1, c);
|
return memrefs_conflict_p (xsize, x1, ysize, y1, c);
|
if (GET_CODE (x1) == CONST_INT)
|
if (GET_CODE (x1) == CONST_INT)
|
{
|
{
|
if (GET_CODE (y1) == CONST_INT)
|
if (GET_CODE (y1) == CONST_INT)
|
return memrefs_conflict_p (xsize, x0, ysize, y0,
|
return memrefs_conflict_p (xsize, x0, ysize, y0,
|
c - INTVAL (x1) + INTVAL (y1));
|
c - INTVAL (x1) + INTVAL (y1));
|
else
|
else
|
return memrefs_conflict_p (xsize, x0, ysize, y,
|
return memrefs_conflict_p (xsize, x0, ysize, y,
|
c - INTVAL (x1));
|
c - INTVAL (x1));
|
}
|
}
|
else if (GET_CODE (y1) == CONST_INT)
|
else if (GET_CODE (y1) == CONST_INT)
|
return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
|
return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
|
|
|
return 1;
|
return 1;
|
}
|
}
|
else if (GET_CODE (x1) == CONST_INT)
|
else if (GET_CODE (x1) == CONST_INT)
|
return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1));
|
return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1));
|
}
|
}
|
else if (GET_CODE (y) == PLUS)
|
else if (GET_CODE (y) == PLUS)
|
{
|
{
|
/* The fact that Y is canonicalized means that this
|
/* The fact that Y is canonicalized means that this
|
PLUS rtx is canonicalized. */
|
PLUS rtx is canonicalized. */
|
rtx y0 = XEXP (y, 0);
|
rtx y0 = XEXP (y, 0);
|
rtx y1 = XEXP (y, 1);
|
rtx y1 = XEXP (y, 1);
|
|
|
if (GET_CODE (y1) == CONST_INT)
|
if (GET_CODE (y1) == CONST_INT)
|
return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
|
return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
|
else
|
else
|
return 1;
|
return 1;
|
}
|
}
|
|
|
if (GET_CODE (x) == GET_CODE (y))
|
if (GET_CODE (x) == GET_CODE (y))
|
switch (GET_CODE (x))
|
switch (GET_CODE (x))
|
{
|
{
|
case MULT:
|
case MULT:
|
{
|
{
|
/* Handle cases where we expect the second operands to be the
|
/* Handle cases where we expect the second operands to be the
|
same, and check only whether the first operand would conflict
|
same, and check only whether the first operand would conflict
|
or not. */
|
or not. */
|
rtx x0, y0;
|
rtx x0, y0;
|
rtx x1 = canon_rtx (XEXP (x, 1));
|
rtx x1 = canon_rtx (XEXP (x, 1));
|
rtx y1 = canon_rtx (XEXP (y, 1));
|
rtx y1 = canon_rtx (XEXP (y, 1));
|
if (! rtx_equal_for_memref_p (x1, y1))
|
if (! rtx_equal_for_memref_p (x1, y1))
|
return 1;
|
return 1;
|
x0 = canon_rtx (XEXP (x, 0));
|
x0 = canon_rtx (XEXP (x, 0));
|
y0 = canon_rtx (XEXP (y, 0));
|
y0 = canon_rtx (XEXP (y, 0));
|
if (rtx_equal_for_memref_p (x0, y0))
|
if (rtx_equal_for_memref_p (x0, y0))
|
return (xsize == 0 || ysize == 0
|
return (xsize == 0 || ysize == 0
|
|| (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0));
|
|| (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0));
|
|
|
/* Can't properly adjust our sizes. */
|
/* Can't properly adjust our sizes. */
|
if (GET_CODE (x1) != CONST_INT)
|
if (GET_CODE (x1) != CONST_INT)
|
return 1;
|
return 1;
|
xsize /= INTVAL (x1);
|
xsize /= INTVAL (x1);
|
ysize /= INTVAL (x1);
|
ysize /= INTVAL (x1);
|
c /= INTVAL (x1);
|
c /= INTVAL (x1);
|
return memrefs_conflict_p (xsize, x0, ysize, y0, c);
|
return memrefs_conflict_p (xsize, x0, ysize, y0, c);
|
}
|
}
|
|
|
default:
|
default:
|
break;
|
break;
|
}
|
}
|
|
|
/* Treat an access through an AND (e.g. a subword access on an Alpha)
|
/* Treat an access through an AND (e.g. a subword access on an Alpha)
|
as an access with indeterminate size. Assume that references
|
as an access with indeterminate size. Assume that references
|
besides AND are aligned, so if the size of the other reference is
|
besides AND are aligned, so if the size of the other reference is
|
at least as large as the alignment, assume no other overlap. */
|
at least as large as the alignment, assume no other overlap. */
|
if (GET_CODE (x) == AND && GET_CODE (XEXP (x, 1)) == CONST_INT)
|
if (GET_CODE (x) == AND && GET_CODE (XEXP (x, 1)) == CONST_INT)
|
{
|
{
|
if (GET_CODE (y) == AND || ysize < -INTVAL (XEXP (x, 1)))
|
if (GET_CODE (y) == AND || ysize < -INTVAL (XEXP (x, 1)))
|
xsize = -1;
|
xsize = -1;
|
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), ysize, y, c);
|
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), ysize, y, c);
|
}
|
}
|
if (GET_CODE (y) == AND && GET_CODE (XEXP (y, 1)) == CONST_INT)
|
if (GET_CODE (y) == AND && GET_CODE (XEXP (y, 1)) == CONST_INT)
|
{
|
{
|
/* ??? If we are indexing far enough into the array/structure, we
|
/* ??? If we are indexing far enough into the array/structure, we
|
may yet be able to determine that we can not overlap. But we
|
may yet be able to determine that we can not overlap. But we
|
also need to that we are far enough from the end not to overlap
|
also need to that we are far enough from the end not to overlap
|
a following reference, so we do nothing with that for now. */
|
a following reference, so we do nothing with that for now. */
|
if (GET_CODE (x) == AND || xsize < -INTVAL (XEXP (y, 1)))
|
if (GET_CODE (x) == AND || xsize < -INTVAL (XEXP (y, 1)))
|
ysize = -1;
|
ysize = -1;
|
return memrefs_conflict_p (xsize, x, ysize, canon_rtx (XEXP (y, 0)), c);
|
return memrefs_conflict_p (xsize, x, ysize, canon_rtx (XEXP (y, 0)), c);
|
}
|
}
|
|
|
if (CONSTANT_P (x))
|
if (CONSTANT_P (x))
|
{
|
{
|
if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT)
|
if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT)
|
{
|
{
|
c += (INTVAL (y) - INTVAL (x));
|
c += (INTVAL (y) - INTVAL (x));
|
return (xsize <= 0 || ysize <= 0
|
return (xsize <= 0 || ysize <= 0
|
|| (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0));
|
|| (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0));
|
}
|
}
|
|
|
if (GET_CODE (x) == CONST)
|
if (GET_CODE (x) == CONST)
|
{
|
{
|
if (GET_CODE (y) == CONST)
|
if (GET_CODE (y) == CONST)
|
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)),
|
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)),
|
ysize, canon_rtx (XEXP (y, 0)), c);
|
ysize, canon_rtx (XEXP (y, 0)), c);
|
else
|
else
|
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)),
|
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)),
|
ysize, y, c);
|
ysize, y, c);
|
}
|
}
|
if (GET_CODE (y) == CONST)
|
if (GET_CODE (y) == CONST)
|
return memrefs_conflict_p (xsize, x, ysize,
|
return memrefs_conflict_p (xsize, x, ysize,
|
canon_rtx (XEXP (y, 0)), c);
|
canon_rtx (XEXP (y, 0)), c);
|
|
|
if (CONSTANT_P (y))
|
if (CONSTANT_P (y))
|
return (xsize <= 0 || ysize <= 0
|
return (xsize <= 0 || ysize <= 0
|
|| (rtx_equal_for_memref_p (x, y)
|
|| (rtx_equal_for_memref_p (x, y)
|
&& ((c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))));
|
&& ((c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))));
|
|
|
return 1;
|
return 1;
|
}
|
}
|
return 1;
|
return 1;
|
}
|
}
|
|
|
/* Functions to compute memory dependencies.
|
/* Functions to compute memory dependencies.
|
|
|
Since we process the insns in execution order, we can build tables
|
Since we process the insns in execution order, we can build tables
|
to keep track of what registers are fixed (and not aliased), what registers
|
to keep track of what registers are fixed (and not aliased), what registers
|
are varying in known ways, and what registers are varying in unknown
|
are varying in known ways, and what registers are varying in unknown
|
ways.
|
ways.
|
|
|
If both memory references are volatile, then there must always be a
|
If both memory references are volatile, then there must always be a
|
dependence between the two references, since their order can not be
|
dependence between the two references, since their order can not be
|
changed. A volatile and non-volatile reference can be interchanged
|
changed. A volatile and non-volatile reference can be interchanged
|
though.
|
though.
|
|
|
A MEM_IN_STRUCT reference at a non-AND varying address can never
|
A MEM_IN_STRUCT reference at a non-AND varying address can never
|
conflict with a non-MEM_IN_STRUCT reference at a fixed address. We
|
conflict with a non-MEM_IN_STRUCT reference at a fixed address. We
|
also must allow AND addresses, because they may generate accesses
|
also must allow AND addresses, because they may generate accesses
|
outside the object being referenced. This is used to generate
|
outside the object being referenced. This is used to generate
|
aligned addresses from unaligned addresses, for instance, the alpha
|
aligned addresses from unaligned addresses, for instance, the alpha
|
storeqi_unaligned pattern. */
|
storeqi_unaligned pattern. */
|
|
|
/* Read dependence: X is read after read in MEM takes place. There can
|
/* Read dependence: X is read after read in MEM takes place. There can
|
only be a dependence here if both reads are volatile. */
|
only be a dependence here if both reads are volatile. */
|
|
|
int
|
int
|
read_dependence (rtx mem, rtx x)
|
read_dependence (rtx mem, rtx x)
|
{
|
{
|
return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem);
|
return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem);
|
}
|
}
|
|
|
/* Returns MEM1 if and only if MEM1 is a scalar at a fixed address and
|
/* Returns MEM1 if and only if MEM1 is a scalar at a fixed address and
|
MEM2 is a reference to a structure at a varying address, or returns
|
MEM2 is a reference to a structure at a varying address, or returns
|
MEM2 if vice versa. Otherwise, returns NULL_RTX. If a non-NULL
|
MEM2 if vice versa. Otherwise, returns NULL_RTX. If a non-NULL
|
value is returned MEM1 and MEM2 can never alias. VARIES_P is used
|
value is returned MEM1 and MEM2 can never alias. VARIES_P is used
|
to decide whether or not an address may vary; it should return
|
to decide whether or not an address may vary; it should return
|
nonzero whenever variation is possible.
|
nonzero whenever variation is possible.
|
MEM1_ADDR and MEM2_ADDR are the addresses of MEM1 and MEM2. */
|
MEM1_ADDR and MEM2_ADDR are the addresses of MEM1 and MEM2. */
|
|
|
static rtx
|
static rtx
|
fixed_scalar_and_varying_struct_p (rtx mem1, rtx mem2, rtx mem1_addr,
|
fixed_scalar_and_varying_struct_p (rtx mem1, rtx mem2, rtx mem1_addr,
|
rtx mem2_addr,
|
rtx mem2_addr,
|
int (*varies_p) (rtx, int))
|
int (*varies_p) (rtx, int))
|
{
|
{
|
if (! flag_strict_aliasing)
|
if (! flag_strict_aliasing)
|
return NULL_RTX;
|
return NULL_RTX;
|
|
|
if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2)
|
if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2)
|
&& !varies_p (mem1_addr, 1) && varies_p (mem2_addr, 1))
|
&& !varies_p (mem1_addr, 1) && varies_p (mem2_addr, 1))
|
/* MEM1 is a scalar at a fixed address; MEM2 is a struct at a
|
/* MEM1 is a scalar at a fixed address; MEM2 is a struct at a
|
varying address. */
|
varying address. */
|
return mem1;
|
return mem1;
|
|
|
if (MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2)
|
if (MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2)
|
&& varies_p (mem1_addr, 1) && !varies_p (mem2_addr, 1))
|
&& varies_p (mem1_addr, 1) && !varies_p (mem2_addr, 1))
|
/* MEM2 is a scalar at a fixed address; MEM1 is a struct at a
|
/* MEM2 is a scalar at a fixed address; MEM1 is a struct at a
|
varying address. */
|
varying address. */
|
return mem2;
|
return mem2;
|
|
|
return NULL_RTX;
|
return NULL_RTX;
|
}
|
}
|
|
|
/* Returns nonzero if something about the mode or address format MEM1
|
/* Returns nonzero if something about the mode or address format MEM1
|
indicates that it might well alias *anything*. */
|
indicates that it might well alias *anything*. */
|
|
|
static int
|
static int
|
aliases_everything_p (rtx mem)
|
aliases_everything_p (rtx mem)
|
{
|
{
|
if (GET_CODE (XEXP (mem, 0)) == AND)
|
if (GET_CODE (XEXP (mem, 0)) == AND)
|
/* If the address is an AND, it's very hard to know at what it is
|
/* If the address is an AND, it's very hard to know at what it is
|
actually pointing. */
|
actually pointing. */
|
return 1;
|
return 1;
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Return true if we can determine that the fields referenced cannot
|
/* Return true if we can determine that the fields referenced cannot
|
overlap for any pair of objects. */
|
overlap for any pair of objects. */
|
|
|
static bool
|
static bool
|
nonoverlapping_component_refs_p (tree x, tree y)
|
nonoverlapping_component_refs_p (tree x, tree y)
|
{
|
{
|
tree fieldx, fieldy, typex, typey, orig_y;
|
tree fieldx, fieldy, typex, typey, orig_y;
|
|
|
do
|
do
|
{
|
{
|
/* The comparison has to be done at a common type, since we don't
|
/* The comparison has to be done at a common type, since we don't
|
know how the inheritance hierarchy works. */
|
know how the inheritance hierarchy works. */
|
orig_y = y;
|
orig_y = y;
|
do
|
do
|
{
|
{
|
fieldx = TREE_OPERAND (x, 1);
|
fieldx = TREE_OPERAND (x, 1);
|
typex = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldx));
|
typex = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldx));
|
|
|
y = orig_y;
|
y = orig_y;
|
do
|
do
|
{
|
{
|
fieldy = TREE_OPERAND (y, 1);
|
fieldy = TREE_OPERAND (y, 1);
|
typey = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldy));
|
typey = TYPE_MAIN_VARIANT (DECL_FIELD_CONTEXT (fieldy));
|
|
|
if (typex == typey)
|
if (typex == typey)
|
goto found;
|
goto found;
|
|
|
y = TREE_OPERAND (y, 0);
|
y = TREE_OPERAND (y, 0);
|
}
|
}
|
while (y && TREE_CODE (y) == COMPONENT_REF);
|
while (y && TREE_CODE (y) == COMPONENT_REF);
|
|
|
x = TREE_OPERAND (x, 0);
|
x = TREE_OPERAND (x, 0);
|
}
|
}
|
while (x && TREE_CODE (x) == COMPONENT_REF);
|
while (x && TREE_CODE (x) == COMPONENT_REF);
|
/* Never found a common type. */
|
/* Never found a common type. */
|
return false;
|
return false;
|
|
|
found:
|
found:
|
/* If we're left with accessing different fields of a structure,
|
/* If we're left with accessing different fields of a structure,
|
then no overlap. */
|
then no overlap. */
|
if (TREE_CODE (typex) == RECORD_TYPE
|
if (TREE_CODE (typex) == RECORD_TYPE
|
&& fieldx != fieldy)
|
&& fieldx != fieldy)
|
return true;
|
return true;
|
|
|
/* The comparison on the current field failed. If we're accessing
|
/* The comparison on the current field failed. If we're accessing
|
a very nested structure, look at the next outer level. */
|
a very nested structure, look at the next outer level. */
|
x = TREE_OPERAND (x, 0);
|
x = TREE_OPERAND (x, 0);
|
y = TREE_OPERAND (y, 0);
|
y = TREE_OPERAND (y, 0);
|
}
|
}
|
while (x && y
|
while (x && y
|
&& TREE_CODE (x) == COMPONENT_REF
|
&& TREE_CODE (x) == COMPONENT_REF
|
&& TREE_CODE (y) == COMPONENT_REF);
|
&& TREE_CODE (y) == COMPONENT_REF);
|
|
|
return false;
|
return false;
|
}
|
}
|
|
|
/* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */
|
/* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */
|
|
|
static tree
|
static tree
|
decl_for_component_ref (tree x)
|
decl_for_component_ref (tree x)
|
{
|
{
|
do
|
do
|
{
|
{
|
x = TREE_OPERAND (x, 0);
|
x = TREE_OPERAND (x, 0);
|
}
|
}
|
while (x && TREE_CODE (x) == COMPONENT_REF);
|
while (x && TREE_CODE (x) == COMPONENT_REF);
|
|
|
return x && DECL_P (x) ? x : NULL_TREE;
|
return x && DECL_P (x) ? x : NULL_TREE;
|
}
|
}
|
|
|
/* Walk up the COMPONENT_REF list and adjust OFFSET to compensate for the
|
/* Walk up the COMPONENT_REF list and adjust OFFSET to compensate for the
|
offset of the field reference. */
|
offset of the field reference. */
|
|
|
static rtx
|
static rtx
|
adjust_offset_for_component_ref (tree x, rtx offset)
|
adjust_offset_for_component_ref (tree x, rtx offset)
|
{
|
{
|
HOST_WIDE_INT ioffset;
|
HOST_WIDE_INT ioffset;
|
|
|
if (! offset)
|
if (! offset)
|
return NULL_RTX;
|
return NULL_RTX;
|
|
|
ioffset = INTVAL (offset);
|
ioffset = INTVAL (offset);
|
do
|
do
|
{
|
{
|
tree offset = component_ref_field_offset (x);
|
tree offset = component_ref_field_offset (x);
|
tree field = TREE_OPERAND (x, 1);
|
tree field = TREE_OPERAND (x, 1);
|
|
|
if (! host_integerp (offset, 1))
|
if (! host_integerp (offset, 1))
|
return NULL_RTX;
|
return NULL_RTX;
|
ioffset += (tree_low_cst (offset, 1)
|
ioffset += (tree_low_cst (offset, 1)
|
+ (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)
|
+ (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)
|
/ BITS_PER_UNIT));
|
/ BITS_PER_UNIT));
|
|
|
x = TREE_OPERAND (x, 0);
|
x = TREE_OPERAND (x, 0);
|
}
|
}
|
while (x && TREE_CODE (x) == COMPONENT_REF);
|
while (x && TREE_CODE (x) == COMPONENT_REF);
|
|
|
return GEN_INT (ioffset);
|
return GEN_INT (ioffset);
|
}
|
}
|
|
|
/* Return nonzero if we can determine the exprs corresponding to memrefs
|
/* Return nonzero if we can determine the exprs corresponding to memrefs
|
X and Y and they do not overlap. */
|
X and Y and they do not overlap. */
|
|
|
static int
|
static int
|
nonoverlapping_memrefs_p (rtx x, rtx y)
|
nonoverlapping_memrefs_p (rtx x, rtx y)
|
{
|
{
|
tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);
|
tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);
|
rtx rtlx, rtly;
|
rtx rtlx, rtly;
|
rtx basex, basey;
|
rtx basex, basey;
|
rtx moffsetx, moffsety;
|
rtx moffsetx, moffsety;
|
HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem;
|
HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem;
|
|
|
/* Unless both have exprs, we can't tell anything. */
|
/* Unless both have exprs, we can't tell anything. */
|
if (exprx == 0 || expry == 0)
|
if (exprx == 0 || expry == 0)
|
return 0;
|
return 0;
|
|
|
/* If both are field references, we may be able to determine something. */
|
/* If both are field references, we may be able to determine something. */
|
if (TREE_CODE (exprx) == COMPONENT_REF
|
if (TREE_CODE (exprx) == COMPONENT_REF
|
&& TREE_CODE (expry) == COMPONENT_REF
|
&& TREE_CODE (expry) == COMPONENT_REF
|
&& nonoverlapping_component_refs_p (exprx, expry))
|
&& nonoverlapping_component_refs_p (exprx, expry))
|
return 1;
|
return 1;
|
|
|
|
|
/* If the field reference test failed, look at the DECLs involved. */
|
/* If the field reference test failed, look at the DECLs involved. */
|
moffsetx = MEM_OFFSET (x);
|
moffsetx = MEM_OFFSET (x);
|
if (TREE_CODE (exprx) == COMPONENT_REF)
|
if (TREE_CODE (exprx) == COMPONENT_REF)
|
{
|
{
|
if (TREE_CODE (expry) == VAR_DECL
|
if (TREE_CODE (expry) == VAR_DECL
|
&& POINTER_TYPE_P (TREE_TYPE (expry)))
|
&& POINTER_TYPE_P (TREE_TYPE (expry)))
|
{
|
{
|
tree field = TREE_OPERAND (exprx, 1);
|
tree field = TREE_OPERAND (exprx, 1);
|
tree fieldcontext = DECL_FIELD_CONTEXT (field);
|
tree fieldcontext = DECL_FIELD_CONTEXT (field);
|
if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
|
if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
|
TREE_TYPE (field)))
|
TREE_TYPE (field)))
|
return 1;
|
return 1;
|
}
|
}
|
{
|
{
|
tree t = decl_for_component_ref (exprx);
|
tree t = decl_for_component_ref (exprx);
|
if (! t)
|
if (! t)
|
return 0;
|
return 0;
|
moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
|
moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
|
exprx = t;
|
exprx = t;
|
}
|
}
|
}
|
}
|
else if (INDIRECT_REF_P (exprx))
|
else if (INDIRECT_REF_P (exprx))
|
{
|
{
|
exprx = TREE_OPERAND (exprx, 0);
|
exprx = TREE_OPERAND (exprx, 0);
|
if (flag_argument_noalias < 2
|
if (flag_argument_noalias < 2
|
|| TREE_CODE (exprx) != PARM_DECL)
|
|| TREE_CODE (exprx) != PARM_DECL)
|
return 0;
|
return 0;
|
}
|
}
|
|
|
moffsety = MEM_OFFSET (y);
|
moffsety = MEM_OFFSET (y);
|
if (TREE_CODE (expry) == COMPONENT_REF)
|
if (TREE_CODE (expry) == COMPONENT_REF)
|
{
|
{
|
if (TREE_CODE (exprx) == VAR_DECL
|
if (TREE_CODE (exprx) == VAR_DECL
|
&& POINTER_TYPE_P (TREE_TYPE (exprx)))
|
&& POINTER_TYPE_P (TREE_TYPE (exprx)))
|
{
|
{
|
tree field = TREE_OPERAND (expry, 1);
|
tree field = TREE_OPERAND (expry, 1);
|
tree fieldcontext = DECL_FIELD_CONTEXT (field);
|
tree fieldcontext = DECL_FIELD_CONTEXT (field);
|
if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
|
if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
|
TREE_TYPE (field)))
|
TREE_TYPE (field)))
|
return 1;
|
return 1;
|
}
|
}
|
{
|
{
|
tree t = decl_for_component_ref (expry);
|
tree t = decl_for_component_ref (expry);
|
if (! t)
|
if (! t)
|
return 0;
|
return 0;
|
moffsety = adjust_offset_for_component_ref (expry, moffsety);
|
moffsety = adjust_offset_for_component_ref (expry, moffsety);
|
expry = t;
|
expry = t;
|
}
|
}
|
}
|
}
|
else if (INDIRECT_REF_P (expry))
|
else if (INDIRECT_REF_P (expry))
|
{
|
{
|
expry = TREE_OPERAND (expry, 0);
|
expry = TREE_OPERAND (expry, 0);
|
if (flag_argument_noalias < 2
|
if (flag_argument_noalias < 2
|
|| TREE_CODE (expry) != PARM_DECL)
|
|| TREE_CODE (expry) != PARM_DECL)
|
return 0;
|
return 0;
|
}
|
}
|
|
|
if (! DECL_P (exprx) || ! DECL_P (expry))
|
if (! DECL_P (exprx) || ! DECL_P (expry))
|
return 0;
|
return 0;
|
|
|
rtlx = DECL_RTL (exprx);
|
rtlx = DECL_RTL (exprx);
|
rtly = DECL_RTL (expry);
|
rtly = DECL_RTL (expry);
|
|
|
/* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they
|
/* If either RTL is not a MEM, it must be a REG or CONCAT, meaning they
|
can't overlap unless they are the same because we never reuse that part
|
can't overlap unless they are the same because we never reuse that part
|
of the stack frame used for locals for spilled pseudos. */
|
of the stack frame used for locals for spilled pseudos. */
|
if ((!MEM_P (rtlx) || !MEM_P (rtly))
|
if ((!MEM_P (rtlx) || !MEM_P (rtly))
|
&& ! rtx_equal_p (rtlx, rtly))
|
&& ! rtx_equal_p (rtlx, rtly))
|
return 1;
|
return 1;
|
|
|
/* Get the base and offsets of both decls. If either is a register, we
|
/* Get the base and offsets of both decls. If either is a register, we
|
know both are and are the same, so use that as the base. The only
|
know both are and are the same, so use that as the base. The only
|
we can avoid overlap is if we can deduce that they are nonoverlapping
|
we can avoid overlap is if we can deduce that they are nonoverlapping
|
pieces of that decl, which is very rare. */
|
pieces of that decl, which is very rare. */
|
basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx;
|
basex = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx;
|
if (GET_CODE (basex) == PLUS && GET_CODE (XEXP (basex, 1)) == CONST_INT)
|
if (GET_CODE (basex) == PLUS && GET_CODE (XEXP (basex, 1)) == CONST_INT)
|
offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0);
|
offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0);
|
|
|
basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly;
|
basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly;
|
if (GET_CODE (basey) == PLUS && GET_CODE (XEXP (basey, 1)) == CONST_INT)
|
if (GET_CODE (basey) == PLUS && GET_CODE (XEXP (basey, 1)) == CONST_INT)
|
offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0);
|
offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0);
|
|
|
/* If the bases are different, we know they do not overlap if both
|
/* If the bases are different, we know they do not overlap if both
|
are constants or if one is a constant and the other a pointer into the
|
are constants or if one is a constant and the other a pointer into the
|
stack frame. Otherwise a different base means we can't tell if they
|
stack frame. Otherwise a different base means we can't tell if they
|
overlap or not. */
|
overlap or not. */
|
if (! rtx_equal_p (basex, basey))
|
if (! rtx_equal_p (basex, basey))
|
return ((CONSTANT_P (basex) && CONSTANT_P (basey))
|
return ((CONSTANT_P (basex) && CONSTANT_P (basey))
|
|| (CONSTANT_P (basex) && REG_P (basey)
|
|| (CONSTANT_P (basex) && REG_P (basey)
|
&& REGNO_PTR_FRAME_P (REGNO (basey)))
|
&& REGNO_PTR_FRAME_P (REGNO (basey)))
|
|| (CONSTANT_P (basey) && REG_P (basex)
|
|| (CONSTANT_P (basey) && REG_P (basex)
|
&& REGNO_PTR_FRAME_P (REGNO (basex))));
|
&& REGNO_PTR_FRAME_P (REGNO (basex))));
|
|
|
sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx))
|
sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx))
|
: MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx))
|
: MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx))
|
: -1);
|
: -1);
|
sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly))
|
sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly))
|
: MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) :
|
: MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) :
|
-1);
|
-1);
|
|
|
/* If we have an offset for either memref, it can update the values computed
|
/* If we have an offset for either memref, it can update the values computed
|
above. */
|
above. */
|
if (moffsetx)
|
if (moffsetx)
|
offsetx += INTVAL (moffsetx), sizex -= INTVAL (moffsetx);
|
offsetx += INTVAL (moffsetx), sizex -= INTVAL (moffsetx);
|
if (moffsety)
|
if (moffsety)
|
offsety += INTVAL (moffsety), sizey -= INTVAL (moffsety);
|
offsety += INTVAL (moffsety), sizey -= INTVAL (moffsety);
|
|
|
/* If a memref has both a size and an offset, we can use the smaller size.
|
/* If a memref has both a size and an offset, we can use the smaller size.
|
We can't do this if the offset isn't known because we must view this
|
We can't do this if the offset isn't known because we must view this
|
memref as being anywhere inside the DECL's MEM. */
|
memref as being anywhere inside the DECL's MEM. */
|
if (MEM_SIZE (x) && moffsetx)
|
if (MEM_SIZE (x) && moffsetx)
|
sizex = INTVAL (MEM_SIZE (x));
|
sizex = INTVAL (MEM_SIZE (x));
|
if (MEM_SIZE (y) && moffsety)
|
if (MEM_SIZE (y) && moffsety)
|
sizey = INTVAL (MEM_SIZE (y));
|
sizey = INTVAL (MEM_SIZE (y));
|
|
|
/* Put the values of the memref with the lower offset in X's values. */
|
/* Put the values of the memref with the lower offset in X's values. */
|
if (offsetx > offsety)
|
if (offsetx > offsety)
|
{
|
{
|
tem = offsetx, offsetx = offsety, offsety = tem;
|
tem = offsetx, offsetx = offsety, offsety = tem;
|
tem = sizex, sizex = sizey, sizey = tem;
|
tem = sizex, sizex = sizey, sizey = tem;
|
}
|
}
|
|
|
/* If we don't know the size of the lower-offset value, we can't tell
|
/* If we don't know the size of the lower-offset value, we can't tell
|
if they conflict. Otherwise, we do the test. */
|
if they conflict. Otherwise, we do the test. */
|
return sizex >= 0 && offsety >= offsetx + sizex;
|
return sizex >= 0 && offsety >= offsetx + sizex;
|
}
|
}
|
|
|
/* True dependence: X is read after store in MEM takes place. */
|
/* True dependence: X is read after store in MEM takes place. */
|
|
|
int
|
int
|
true_dependence (rtx mem, enum machine_mode mem_mode, rtx x,
|
true_dependence (rtx mem, enum machine_mode mem_mode, rtx x,
|
int (*varies) (rtx, int))
|
int (*varies) (rtx, int))
|
{
|
{
|
rtx x_addr, mem_addr;
|
rtx x_addr, mem_addr;
|
rtx base;
|
rtx base;
|
|
|
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
|
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
|
return 1;
|
return 1;
|
|
|
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
|
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
|
This is used in epilogue deallocation functions. */
|
This is used in epilogue deallocation functions. */
|
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
|
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
|
return 1;
|
return 1;
|
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
|
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
|
return 1;
|
return 1;
|
if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
|
if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
|
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
|
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
|
return 1;
|
return 1;
|
|
|
if (DIFFERENT_ALIAS_SETS_P (x, mem))
|
if (DIFFERENT_ALIAS_SETS_P (x, mem))
|
return 0;
|
return 0;
|
|
|
/* Read-only memory is by definition never modified, and therefore can't
|
/* Read-only memory is by definition never modified, and therefore can't
|
conflict with anything. We don't expect to find read-only set on MEM,
|
conflict with anything. We don't expect to find read-only set on MEM,
|
but stupid user tricks can produce them, so don't die. */
|
but stupid user tricks can produce them, so don't die. */
|
if (MEM_READONLY_P (x))
|
if (MEM_READONLY_P (x))
|
return 0;
|
return 0;
|
|
|
if (nonoverlapping_memrefs_p (mem, x))
|
if (nonoverlapping_memrefs_p (mem, x))
|
return 0;
|
return 0;
|
|
|
if (mem_mode == VOIDmode)
|
if (mem_mode == VOIDmode)
|
mem_mode = GET_MODE (mem);
|
mem_mode = GET_MODE (mem);
|
|
|
x_addr = get_addr (XEXP (x, 0));
|
x_addr = get_addr (XEXP (x, 0));
|
mem_addr = get_addr (XEXP (mem, 0));
|
mem_addr = get_addr (XEXP (mem, 0));
|
|
|
base = find_base_term (x_addr);
|
base = find_base_term (x_addr);
|
if (base && (GET_CODE (base) == LABEL_REF
|
if (base && (GET_CODE (base) == LABEL_REF
|
|| (GET_CODE (base) == SYMBOL_REF
|
|| (GET_CODE (base) == SYMBOL_REF
|
&& CONSTANT_POOL_ADDRESS_P (base))))
|
&& CONSTANT_POOL_ADDRESS_P (base))))
|
return 0;
|
return 0;
|
|
|
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
|
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
|
return 0;
|
return 0;
|
|
|
x_addr = canon_rtx (x_addr);
|
x_addr = canon_rtx (x_addr);
|
mem_addr = canon_rtx (mem_addr);
|
mem_addr = canon_rtx (mem_addr);
|
|
|
if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
|
if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
|
SIZE_FOR_MODE (x), x_addr, 0))
|
SIZE_FOR_MODE (x), x_addr, 0))
|
return 0;
|
return 0;
|
|
|
if (aliases_everything_p (x))
|
if (aliases_everything_p (x))
|
return 1;
|
return 1;
|
|
|
/* We cannot use aliases_everything_p to test MEM, since we must look
|
/* We cannot use aliases_everything_p to test MEM, since we must look
|
at MEM_MODE, rather than GET_MODE (MEM). */
|
at MEM_MODE, rather than GET_MODE (MEM). */
|
if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
|
if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
|
return 1;
|
return 1;
|
|
|
/* In true_dependence we also allow BLKmode to alias anything. Why
|
/* In true_dependence we also allow BLKmode to alias anything. Why
|
don't we do this in anti_dependence and output_dependence? */
|
don't we do this in anti_dependence and output_dependence? */
|
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
|
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
|
return 1;
|
return 1;
|
|
|
return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
|
return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
|
varies);
|
varies);
|
}
|
}
|
|
|
/* Canonical true dependence: X is read after store in MEM takes place.
|
/* Canonical true dependence: X is read after store in MEM takes place.
|
Variant of true_dependence which assumes MEM has already been
|
Variant of true_dependence which assumes MEM has already been
|
canonicalized (hence we no longer do that here).
|
canonicalized (hence we no longer do that here).
|
The mem_addr argument has been added, since true_dependence computed
|
The mem_addr argument has been added, since true_dependence computed
|
this value prior to canonicalizing. */
|
this value prior to canonicalizing. */
|
|
|
int
|
int
|
canon_true_dependence (rtx mem, enum machine_mode mem_mode, rtx mem_addr,
|
canon_true_dependence (rtx mem, enum machine_mode mem_mode, rtx mem_addr,
|
rtx x, int (*varies) (rtx, int))
|
rtx x, int (*varies) (rtx, int))
|
{
|
{
|
rtx x_addr;
|
rtx x_addr;
|
|
|
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
|
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
|
return 1;
|
return 1;
|
|
|
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
|
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
|
This is used in epilogue deallocation functions. */
|
This is used in epilogue deallocation functions. */
|
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
|
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
|
return 1;
|
return 1;
|
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
|
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
|
return 1;
|
return 1;
|
if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
|
if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
|
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
|
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
|
return 1;
|
return 1;
|
|
|
if (DIFFERENT_ALIAS_SETS_P (x, mem))
|
if (DIFFERENT_ALIAS_SETS_P (x, mem))
|
return 0;
|
return 0;
|
|
|
/* Read-only memory is by definition never modified, and therefore can't
|
/* Read-only memory is by definition never modified, and therefore can't
|
conflict with anything. We don't expect to find read-only set on MEM,
|
conflict with anything. We don't expect to find read-only set on MEM,
|
but stupid user tricks can produce them, so don't die. */
|
but stupid user tricks can produce them, so don't die. */
|
if (MEM_READONLY_P (x))
|
if (MEM_READONLY_P (x))
|
return 0;
|
return 0;
|
|
|
if (nonoverlapping_memrefs_p (x, mem))
|
if (nonoverlapping_memrefs_p (x, mem))
|
return 0;
|
return 0;
|
|
|
x_addr = get_addr (XEXP (x, 0));
|
x_addr = get_addr (XEXP (x, 0));
|
|
|
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
|
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
|
return 0;
|
return 0;
|
|
|
x_addr = canon_rtx (x_addr);
|
x_addr = canon_rtx (x_addr);
|
if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
|
if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
|
SIZE_FOR_MODE (x), x_addr, 0))
|
SIZE_FOR_MODE (x), x_addr, 0))
|
return 0;
|
return 0;
|
|
|
if (aliases_everything_p (x))
|
if (aliases_everything_p (x))
|
return 1;
|
return 1;
|
|
|
/* We cannot use aliases_everything_p to test MEM, since we must look
|
/* We cannot use aliases_everything_p to test MEM, since we must look
|
at MEM_MODE, rather than GET_MODE (MEM). */
|
at MEM_MODE, rather than GET_MODE (MEM). */
|
if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
|
if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
|
return 1;
|
return 1;
|
|
|
/* In true_dependence we also allow BLKmode to alias anything. Why
|
/* In true_dependence we also allow BLKmode to alias anything. Why
|
don't we do this in anti_dependence and output_dependence? */
|
don't we do this in anti_dependence and output_dependence? */
|
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
|
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
|
return 1;
|
return 1;
|
|
|
return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
|
return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
|
varies);
|
varies);
|
}
|
}
|
|
|
/* Returns nonzero if a write to X might alias a previous read from
|
/* Returns nonzero if a write to X might alias a previous read from
|
(or, if WRITEP is nonzero, a write to) MEM. */
|
(or, if WRITEP is nonzero, a write to) MEM. */
|
|
|
static int
|
static int
|
write_dependence_p (rtx mem, rtx x, int writep)
|
write_dependence_p (rtx mem, rtx x, int writep)
|
{
|
{
|
rtx x_addr, mem_addr;
|
rtx x_addr, mem_addr;
|
rtx fixed_scalar;
|
rtx fixed_scalar;
|
rtx base;
|
rtx base;
|
|
|
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
|
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
|
return 1;
|
return 1;
|
|
|
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
|
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
|
This is used in epilogue deallocation functions. */
|
This is used in epilogue deallocation functions. */
|
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
|
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
|
return 1;
|
return 1;
|
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
|
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
|
return 1;
|
return 1;
|
if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
|
if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
|
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
|
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
|
return 1;
|
return 1;
|
|
|
if (DIFFERENT_ALIAS_SETS_P (x, mem))
|
if (DIFFERENT_ALIAS_SETS_P (x, mem))
|
return 0;
|
return 0;
|
|
|
/* A read from read-only memory can't conflict with read-write memory. */
|
/* A read from read-only memory can't conflict with read-write memory. */
|
if (!writep && MEM_READONLY_P (mem))
|
if (!writep && MEM_READONLY_P (mem))
|
return 0;
|
return 0;
|
|
|
if (nonoverlapping_memrefs_p (x, mem))
|
if (nonoverlapping_memrefs_p (x, mem))
|
return 0;
|
return 0;
|
|
|
x_addr = get_addr (XEXP (x, 0));
|
x_addr = get_addr (XEXP (x, 0));
|
mem_addr = get_addr (XEXP (mem, 0));
|
mem_addr = get_addr (XEXP (mem, 0));
|
|
|
if (! writep)
|
if (! writep)
|
{
|
{
|
base = find_base_term (mem_addr);
|
base = find_base_term (mem_addr);
|
if (base && (GET_CODE (base) == LABEL_REF
|
if (base && (GET_CODE (base) == LABEL_REF
|
|| (GET_CODE (base) == SYMBOL_REF
|
|| (GET_CODE (base) == SYMBOL_REF
|
&& CONSTANT_POOL_ADDRESS_P (base))))
|
&& CONSTANT_POOL_ADDRESS_P (base))))
|
return 0;
|
return 0;
|
}
|
}
|
|
|
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x),
|
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x),
|
GET_MODE (mem)))
|
GET_MODE (mem)))
|
return 0;
|
return 0;
|
|
|
x_addr = canon_rtx (x_addr);
|
x_addr = canon_rtx (x_addr);
|
mem_addr = canon_rtx (mem_addr);
|
mem_addr = canon_rtx (mem_addr);
|
|
|
if (!memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr,
|
if (!memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr,
|
SIZE_FOR_MODE (x), x_addr, 0))
|
SIZE_FOR_MODE (x), x_addr, 0))
|
return 0;
|
return 0;
|
|
|
fixed_scalar
|
fixed_scalar
|
= fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
|
= fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
|
rtx_addr_varies_p);
|
rtx_addr_varies_p);
|
|
|
return (!(fixed_scalar == mem && !aliases_everything_p (x))
|
return (!(fixed_scalar == mem && !aliases_everything_p (x))
|
&& !(fixed_scalar == x && !aliases_everything_p (mem)));
|
&& !(fixed_scalar == x && !aliases_everything_p (mem)));
|
}
|
}
|
|
|
/* Anti dependence: X is written after read in MEM takes place. */
|
/* Anti dependence: X is written after read in MEM takes place. */
|
|
|
int
|
int
|
anti_dependence (rtx mem, rtx x)
|
anti_dependence (rtx mem, rtx x)
|
{
|
{
|
return write_dependence_p (mem, x, /*writep=*/0);
|
return write_dependence_p (mem, x, /*writep=*/0);
|
}
|
}
|
|
|
/* Output dependence: X is written after store in MEM takes place. */
|
/* Output dependence: X is written after store in MEM takes place. */
|
|
|
int
|
int
|
output_dependence (rtx mem, rtx x)
|
output_dependence (rtx mem, rtx x)
|
{
|
{
|
return write_dependence_p (mem, x, /*writep=*/1);
|
return write_dependence_p (mem, x, /*writep=*/1);
|
}
|
}
|
|
|
|
|
void
|
void
|
init_alias_once (void)
|
init_alias_once (void)
|
{
|
{
|
int i;
|
int i;
|
|
|
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
|
/* Check whether this register can hold an incoming pointer
|
/* Check whether this register can hold an incoming pointer
|
argument. FUNCTION_ARG_REGNO_P tests outgoing register
|
argument. FUNCTION_ARG_REGNO_P tests outgoing register
|
numbers, so translate if necessary due to register windows. */
|
numbers, so translate if necessary due to register windows. */
|
if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i))
|
if (FUNCTION_ARG_REGNO_P (OUTGOING_REGNO (i))
|
&& HARD_REGNO_MODE_OK (i, Pmode))
|
&& HARD_REGNO_MODE_OK (i, Pmode))
|
static_reg_base_value[i]
|
static_reg_base_value[i]
|
= gen_rtx_ADDRESS (VOIDmode, gen_rtx_REG (Pmode, i));
|
= gen_rtx_ADDRESS (VOIDmode, gen_rtx_REG (Pmode, i));
|
|
|
static_reg_base_value[STACK_POINTER_REGNUM]
|
static_reg_base_value[STACK_POINTER_REGNUM]
|
= gen_rtx_ADDRESS (Pmode, stack_pointer_rtx);
|
= gen_rtx_ADDRESS (Pmode, stack_pointer_rtx);
|
static_reg_base_value[ARG_POINTER_REGNUM]
|
static_reg_base_value[ARG_POINTER_REGNUM]
|
= gen_rtx_ADDRESS (Pmode, arg_pointer_rtx);
|
= gen_rtx_ADDRESS (Pmode, arg_pointer_rtx);
|
static_reg_base_value[FRAME_POINTER_REGNUM]
|
static_reg_base_value[FRAME_POINTER_REGNUM]
|
= gen_rtx_ADDRESS (Pmode, frame_pointer_rtx);
|
= gen_rtx_ADDRESS (Pmode, frame_pointer_rtx);
|
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
|
#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
|
static_reg_base_value[HARD_FRAME_POINTER_REGNUM]
|
static_reg_base_value[HARD_FRAME_POINTER_REGNUM]
|
= gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
|
= gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
|
#endif
|
#endif
|
}
|
}
|
|
|
/* Set MEMORY_MODIFIED when X modifies DATA (that is assumed
|
/* Set MEMORY_MODIFIED when X modifies DATA (that is assumed
|
to be memory reference. */
|
to be memory reference. */
|
static bool memory_modified;
|
static bool memory_modified;
|
static void
|
static void
|
memory_modified_1 (rtx x, rtx pat ATTRIBUTE_UNUSED, void *data)
|
memory_modified_1 (rtx x, rtx pat ATTRIBUTE_UNUSED, void *data)
|
{
|
{
|
if (MEM_P (x))
|
if (MEM_P (x))
|
{
|
{
|
if (anti_dependence (x, (rtx)data) || output_dependence (x, (rtx)data))
|
if (anti_dependence (x, (rtx)data) || output_dependence (x, (rtx)data))
|
memory_modified = true;
|
memory_modified = true;
|
}
|
}
|
}
|
}
|
|
|
|
|
/* Return true when INSN possibly modify memory contents of MEM
|
/* Return true when INSN possibly modify memory contents of MEM
|
(i.e. address can be modified). */
|
(i.e. address can be modified). */
|
bool
|
bool
|
memory_modified_in_insn_p (rtx mem, rtx insn)
|
memory_modified_in_insn_p (rtx mem, rtx insn)
|
{
|
{
|
if (!INSN_P (insn))
|
if (!INSN_P (insn))
|
return false;
|
return false;
|
memory_modified = false;
|
memory_modified = false;
|
note_stores (PATTERN (insn), memory_modified_1, mem);
|
note_stores (PATTERN (insn), memory_modified_1, mem);
|
return memory_modified;
|
return memory_modified;
|
}
|
}
|
|
|
/* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE
|
/* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE
|
array. */
|
array. */
|
|
|
void
|
void
|
init_alias_analysis (void)
|
init_alias_analysis (void)
|
{
|
{
|
unsigned int maxreg = max_reg_num ();
|
unsigned int maxreg = max_reg_num ();
|
int changed, pass;
|
int changed, pass;
|
int i;
|
int i;
|
unsigned int ui;
|
unsigned int ui;
|
rtx insn;
|
rtx insn;
|
|
|
timevar_push (TV_ALIAS_ANALYSIS);
|
timevar_push (TV_ALIAS_ANALYSIS);
|
|
|
reg_known_value_size = maxreg - FIRST_PSEUDO_REGISTER;
|
reg_known_value_size = maxreg - FIRST_PSEUDO_REGISTER;
|
reg_known_value = ggc_calloc (reg_known_value_size, sizeof (rtx));
|
reg_known_value = ggc_calloc (reg_known_value_size, sizeof (rtx));
|
reg_known_equiv_p = xcalloc (reg_known_value_size, sizeof (bool));
|
reg_known_equiv_p = xcalloc (reg_known_value_size, sizeof (bool));
|
|
|
/* If we have memory allocated from the previous run, use it. */
|
/* If we have memory allocated from the previous run, use it. */
|
if (old_reg_base_value)
|
if (old_reg_base_value)
|
reg_base_value = old_reg_base_value;
|
reg_base_value = old_reg_base_value;
|
|
|
if (reg_base_value)
|
if (reg_base_value)
|
VEC_truncate (rtx, reg_base_value, 0);
|
VEC_truncate (rtx, reg_base_value, 0);
|
|
|
VEC_safe_grow (rtx, gc, reg_base_value, maxreg);
|
VEC_safe_grow (rtx, gc, reg_base_value, maxreg);
|
memset (VEC_address (rtx, reg_base_value), 0,
|
memset (VEC_address (rtx, reg_base_value), 0,
|
sizeof (rtx) * VEC_length (rtx, reg_base_value));
|
sizeof (rtx) * VEC_length (rtx, reg_base_value));
|
|
|
new_reg_base_value = XNEWVEC (rtx, maxreg);
|
new_reg_base_value = XNEWVEC (rtx, maxreg);
|
reg_seen = XNEWVEC (char, maxreg);
|
reg_seen = XNEWVEC (char, maxreg);
|
|
|
/* The basic idea is that each pass through this loop will use the
|
/* The basic idea is that each pass through this loop will use the
|
"constant" information from the previous pass to propagate alias
|
"constant" information from the previous pass to propagate alias
|
information through another level of assignments.
|
information through another level of assignments.
|
|
|
This could get expensive if the assignment chains are long. Maybe
|
This could get expensive if the assignment chains are long. Maybe
|
we should throttle the number of iterations, possibly based on
|
we should throttle the number of iterations, possibly based on
|
the optimization level or flag_expensive_optimizations.
|
the optimization level or flag_expensive_optimizations.
|
|
|
We could propagate more information in the first pass by making use
|
We could propagate more information in the first pass by making use
|
of REG_N_SETS to determine immediately that the alias information
|
of REG_N_SETS to determine immediately that the alias information
|
for a pseudo is "constant".
|
for a pseudo is "constant".
|
|
|
A program with an uninitialized variable can cause an infinite loop
|
A program with an uninitialized variable can cause an infinite loop
|
here. Instead of doing a full dataflow analysis to detect such problems
|
here. Instead of doing a full dataflow analysis to detect such problems
|
we just cap the number of iterations for the loop.
|
we just cap the number of iterations for the loop.
|
|
|
The state of the arrays for the set chain in question does not matter
|
The state of the arrays for the set chain in question does not matter
|
since the program has undefined behavior. */
|
since the program has undefined behavior. */
|
|
|
pass = 0;
|
pass = 0;
|
do
|
do
|
{
|
{
|
/* Assume nothing will change this iteration of the loop. */
|
/* Assume nothing will change this iteration of the loop. */
|
changed = 0;
|
changed = 0;
|
|
|
/* We want to assign the same IDs each iteration of this loop, so
|
/* We want to assign the same IDs each iteration of this loop, so
|
start counting from zero each iteration of the loop. */
|
start counting from zero each iteration of the loop. */
|
unique_id = 0;
|
unique_id = 0;
|
|
|
/* We're at the start of the function each iteration through the
|
/* We're at the start of the function each iteration through the
|
loop, so we're copying arguments. */
|
loop, so we're copying arguments. */
|
copying_arguments = true;
|
copying_arguments = true;
|
|
|
/* Wipe the potential alias information clean for this pass. */
|
/* Wipe the potential alias information clean for this pass. */
|
memset (new_reg_base_value, 0, maxreg * sizeof (rtx));
|
memset (new_reg_base_value, 0, maxreg * sizeof (rtx));
|
|
|
/* Wipe the reg_seen array clean. */
|
/* Wipe the reg_seen array clean. */
|
memset (reg_seen, 0, maxreg);
|
memset (reg_seen, 0, maxreg);
|
|
|
/* Mark all hard registers which may contain an address.
|
/* Mark all hard registers which may contain an address.
|
The stack, frame and argument pointers may contain an address.
|
The stack, frame and argument pointers may contain an address.
|
An argument register which can hold a Pmode value may contain
|
An argument register which can hold a Pmode value may contain
|
an address even if it is not in BASE_REGS.
|
an address even if it is not in BASE_REGS.
|
|
|
The address expression is VOIDmode for an argument and
|
The address expression is VOIDmode for an argument and
|
Pmode for other registers. */
|
Pmode for other registers. */
|
|
|
memcpy (new_reg_base_value, static_reg_base_value,
|
memcpy (new_reg_base_value, static_reg_base_value,
|
FIRST_PSEUDO_REGISTER * sizeof (rtx));
|
FIRST_PSEUDO_REGISTER * sizeof (rtx));
|
|
|
/* Walk the insns adding values to the new_reg_base_value array. */
|
/* Walk the insns adding values to the new_reg_base_value array. */
|
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
|
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
|
{
|
{
|
if (INSN_P (insn))
|
if (INSN_P (insn))
|
{
|
{
|
rtx note, set;
|
rtx note, set;
|
|
|
#if defined (HAVE_prologue) || defined (HAVE_epilogue)
|
#if defined (HAVE_prologue) || defined (HAVE_epilogue)
|
/* The prologue/epilogue insns are not threaded onto the
|
/* The prologue/epilogue insns are not threaded onto the
|
insn chain until after reload has completed. Thus,
|
insn chain until after reload has completed. Thus,
|
there is no sense wasting time checking if INSN is in
|
there is no sense wasting time checking if INSN is in
|
the prologue/epilogue until after reload has completed. */
|
the prologue/epilogue until after reload has completed. */
|
if (reload_completed
|
if (reload_completed
|
&& prologue_epilogue_contains (insn))
|
&& prologue_epilogue_contains (insn))
|
continue;
|
continue;
|
#endif
|
#endif
|
|
|
/* If this insn has a noalias note, process it, Otherwise,
|
/* If this insn has a noalias note, process it, Otherwise,
|
scan for sets. A simple set will have no side effects
|
scan for sets. A simple set will have no side effects
|
which could change the base value of any other register. */
|
which could change the base value of any other register. */
|
|
|
if (GET_CODE (PATTERN (insn)) == SET
|
if (GET_CODE (PATTERN (insn)) == SET
|
&& REG_NOTES (insn) != 0
|
&& REG_NOTES (insn) != 0
|
&& find_reg_note (insn, REG_NOALIAS, NULL_RTX))
|
&& find_reg_note (insn, REG_NOALIAS, NULL_RTX))
|
record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL);
|
record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL);
|
else
|
else
|
note_stores (PATTERN (insn), record_set, NULL);
|
note_stores (PATTERN (insn), record_set, NULL);
|
|
|
set = single_set (insn);
|
set = single_set (insn);
|
|
|
if (set != 0
|
if (set != 0
|
&& REG_P (SET_DEST (set))
|
&& REG_P (SET_DEST (set))
|
&& REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER)
|
&& REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER)
|
{
|
{
|
unsigned int regno = REGNO (SET_DEST (set));
|
unsigned int regno = REGNO (SET_DEST (set));
|
rtx src = SET_SRC (set);
|
rtx src = SET_SRC (set);
|
rtx t;
|
rtx t;
|
|
|
if (REG_NOTES (insn) != 0
|
if (REG_NOTES (insn) != 0
|
&& (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
|
&& (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
|
&& REG_N_SETS (regno) == 1)
|
&& REG_N_SETS (regno) == 1)
|
|| (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
|
|| (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
|
&& GET_CODE (XEXP (note, 0)) != EXPR_LIST
|
&& GET_CODE (XEXP (note, 0)) != EXPR_LIST
|
&& ! rtx_varies_p (XEXP (note, 0), 1)
|
&& ! rtx_varies_p (XEXP (note, 0), 1)
|
&& ! reg_overlap_mentioned_p (SET_DEST (set),
|
&& ! reg_overlap_mentioned_p (SET_DEST (set),
|
XEXP (note, 0)))
|
XEXP (note, 0)))
|
{
|
{
|
set_reg_known_value (regno, XEXP (note, 0));
|
set_reg_known_value (regno, XEXP (note, 0));
|
set_reg_known_equiv_p (regno,
|
set_reg_known_equiv_p (regno,
|
REG_NOTE_KIND (note) == REG_EQUIV);
|
REG_NOTE_KIND (note) == REG_EQUIV);
|
}
|
}
|
else if (REG_N_SETS (regno) == 1
|
else if (REG_N_SETS (regno) == 1
|
&& GET_CODE (src) == PLUS
|
&& GET_CODE (src) == PLUS
|
&& REG_P (XEXP (src, 0))
|
&& REG_P (XEXP (src, 0))
|
&& (t = get_reg_known_value (REGNO (XEXP (src, 0))))
|
&& (t = get_reg_known_value (REGNO (XEXP (src, 0))))
|
&& GET_CODE (XEXP (src, 1)) == CONST_INT)
|
&& GET_CODE (XEXP (src, 1)) == CONST_INT)
|
{
|
{
|
t = plus_constant (t, INTVAL (XEXP (src, 1)));
|
t = plus_constant (t, INTVAL (XEXP (src, 1)));
|
set_reg_known_value (regno, t);
|
set_reg_known_value (regno, t);
|
set_reg_known_equiv_p (regno, 0);
|
set_reg_known_equiv_p (regno, 0);
|
}
|
}
|
else if (REG_N_SETS (regno) == 1
|
else if (REG_N_SETS (regno) == 1
|
&& ! rtx_varies_p (src, 1))
|
&& ! rtx_varies_p (src, 1))
|
{
|
{
|
set_reg_known_value (regno, src);
|
set_reg_known_value (regno, src);
|
set_reg_known_equiv_p (regno, 0);
|
set_reg_known_equiv_p (regno, 0);
|
}
|
}
|
}
|
}
|
}
|
}
|
else if (NOTE_P (insn)
|
else if (NOTE_P (insn)
|
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
|
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
|
copying_arguments = false;
|
copying_arguments = false;
|
}
|
}
|
|
|
/* Now propagate values from new_reg_base_value to reg_base_value. */
|
/* Now propagate values from new_reg_base_value to reg_base_value. */
|
gcc_assert (maxreg == (unsigned int) max_reg_num());
|
gcc_assert (maxreg == (unsigned int) max_reg_num());
|
|
|
for (ui = 0; ui < maxreg; ui++)
|
for (ui = 0; ui < maxreg; ui++)
|
{
|
{
|
if (new_reg_base_value[ui]
|
if (new_reg_base_value[ui]
|
&& new_reg_base_value[ui] != VEC_index (rtx, reg_base_value, ui)
|
&& new_reg_base_value[ui] != VEC_index (rtx, reg_base_value, ui)
|
&& ! rtx_equal_p (new_reg_base_value[ui],
|
&& ! rtx_equal_p (new_reg_base_value[ui],
|
VEC_index (rtx, reg_base_value, ui)))
|
VEC_index (rtx, reg_base_value, ui)))
|
{
|
{
|
VEC_replace (rtx, reg_base_value, ui, new_reg_base_value[ui]);
|
VEC_replace (rtx, reg_base_value, ui, new_reg_base_value[ui]);
|
changed = 1;
|
changed = 1;
|
}
|
}
|
}
|
}
|
}
|
}
|
while (changed && ++pass < MAX_ALIAS_LOOP_PASSES);
|
while (changed && ++pass < MAX_ALIAS_LOOP_PASSES);
|
|
|
/* Fill in the remaining entries. */
|
/* Fill in the remaining entries. */
|
for (i = 0; i < (int)reg_known_value_size; i++)
|
for (i = 0; i < (int)reg_known_value_size; i++)
|
if (reg_known_value[i] == 0)
|
if (reg_known_value[i] == 0)
|
reg_known_value[i] = regno_reg_rtx[i + FIRST_PSEUDO_REGISTER];
|
reg_known_value[i] = regno_reg_rtx[i + FIRST_PSEUDO_REGISTER];
|
|
|
/* Simplify the reg_base_value array so that no register refers to
|
/* Simplify the reg_base_value array so that no register refers to
|
another register, except to special registers indirectly through
|
another register, except to special registers indirectly through
|
ADDRESS expressions.
|
ADDRESS expressions.
|
|
|
In theory this loop can take as long as O(registers^2), but unless
|
In theory this loop can take as long as O(registers^2), but unless
|
there are very long dependency chains it will run in close to linear
|
there are very long dependency chains it will run in close to linear
|
time.
|
time.
|
|
|
This loop may not be needed any longer now that the main loop does
|
This loop may not be needed any longer now that the main loop does
|
a better job at propagating alias information. */
|
a better job at propagating alias information. */
|
pass = 0;
|
pass = 0;
|
do
|
do
|
{
|
{
|
changed = 0;
|
changed = 0;
|
pass++;
|
pass++;
|
for (ui = 0; ui < maxreg; ui++)
|
for (ui = 0; ui < maxreg; ui++)
|
{
|
{
|
rtx base = VEC_index (rtx, reg_base_value, ui);
|
rtx base = VEC_index (rtx, reg_base_value, ui);
|
if (base && REG_P (base))
|
if (base && REG_P (base))
|
{
|
{
|
unsigned int base_regno = REGNO (base);
|
unsigned int base_regno = REGNO (base);
|
if (base_regno == ui) /* register set from itself */
|
if (base_regno == ui) /* register set from itself */
|
VEC_replace (rtx, reg_base_value, ui, 0);
|
VEC_replace (rtx, reg_base_value, ui, 0);
|
else
|
else
|
VEC_replace (rtx, reg_base_value, ui,
|
VEC_replace (rtx, reg_base_value, ui,
|
VEC_index (rtx, reg_base_value, base_regno));
|
VEC_index (rtx, reg_base_value, base_regno));
|
changed = 1;
|
changed = 1;
|
}
|
}
|
}
|
}
|
}
|
}
|
while (changed && pass < MAX_ALIAS_LOOP_PASSES);
|
while (changed && pass < MAX_ALIAS_LOOP_PASSES);
|
|
|
/* Clean up. */
|
/* Clean up. */
|
free (new_reg_base_value);
|
free (new_reg_base_value);
|
new_reg_base_value = 0;
|
new_reg_base_value = 0;
|
free (reg_seen);
|
free (reg_seen);
|
reg_seen = 0;
|
reg_seen = 0;
|
timevar_pop (TV_ALIAS_ANALYSIS);
|
timevar_pop (TV_ALIAS_ANALYSIS);
|
}
|
}
|
|
|
void
|
void
|
end_alias_analysis (void)
|
end_alias_analysis (void)
|
{
|
{
|
old_reg_base_value = reg_base_value;
|
old_reg_base_value = reg_base_value;
|
ggc_free (reg_known_value);
|
ggc_free (reg_known_value);
|
reg_known_value = 0;
|
reg_known_value = 0;
|
reg_known_value_size = 0;
|
reg_known_value_size = 0;
|
free (reg_known_equiv_p);
|
free (reg_known_equiv_p);
|
reg_known_equiv_p = 0;
|
reg_known_equiv_p = 0;
|
}
|
}
|
|
|
#include "gt-alias.h"
|
#include "gt-alias.h"
|
|
|
