/* Alias analysis for GNU C
- Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+ Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
Contributed by John Carr (jfc@mit.edu).
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC is free software; you can redistribute it and/or modify
-it under the terms of the GNU General Public License as published by
-the Free Software Foundation; either version 2, or (at your option)
-any later version.
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
-GNU CC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING. If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA. */
#include "config.h"
#include "system.h"
#include "tree.h"
#include "tm_p.h"
#include "function.h"
-#include "insn-flags.h"
#include "expr.h"
#include "regs.h"
#include "hard-reg-set.h"
+#include "basic-block.h"
#include "flags.h"
#include "output.h"
#include "toplev.h"
+#include "cselib.h"
#include "splay-tree.h"
#include "ggc.h"
+#include "langhooks.h"
/* The alias sets assigned to MEMs assist the back-end in determining
which MEMs can alias which other MEMs. In general, two MEMs in
- different alias sets to not alias each other. There is one
- exception, however. Consider something like:
+ different alias sets cannot alias each other, with one important
+ exception. Consider something like:
struct S {int i; double d; };
|/_ _\|
int double
- (The arrows are directed and point downwards.) If, when comparing
- two alias sets, we can hold one set fixed, trace the other set
- downwards, and at some point find the first set, the two MEMs can
- alias one another. In this situation we say the alias set for
- `struct S' is the `superset' and that those for `int' and `double'
- are `subsets'.
+ (The arrows are directed and point downwards.)
+ In this situation we say the alias set for `struct S' is the
+ `superset' and that those for `int' and `double' are `subsets'.
+
+ To see whether two alias sets can point to the same memory, we must
+ see if either alias set is a subset of the other. We need not trace
+ past immediate descendents, however, since we propagate all
+ grandchildren up one level.
Alias set zero is implicitly a superset of all other alias sets.
However, this is no actual entry for alias set zero. It is an
typedef struct alias_set_entry
{
/* The alias set number, as stored in MEM_ALIAS_SET. */
- int alias_set;
+ HOST_WIDE_INT alias_set;
/* The children of the alias set. These are not just the immediate
- children, but, in fact, all children. So, if we have:
+ children, but, in fact, all descendents. So, if we have:
struct T { struct S s; float f; }
continuing our example above, the children here will be all of
`int', `double', `float', and `struct S'. */
splay_tree children;
+
+ /* Nonzero if would have a child of zero: this effectively makes this
+ alias set the same as alias set zero. */
+ int has_zero_child;
} *alias_set_entry;
-static rtx canon_rtx PARAMS ((rtx));
static int rtx_equal_for_memref_p PARAMS ((rtx, rtx));
static rtx find_symbolic_term PARAMS ((rtx));
+rtx get_addr PARAMS ((rtx));
static int memrefs_conflict_p PARAMS ((int, rtx, int, rtx,
HOST_WIDE_INT));
static void record_set PARAMS ((rtx, rtx, void *));
static rtx find_base_value PARAMS ((rtx));
static int mems_in_disjoint_alias_sets_p PARAMS ((rtx, rtx));
static int insert_subset_children PARAMS ((splay_tree_node, void*));
-static alias_set_entry get_alias_set_entry PARAMS ((int));
-static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, int (*)(rtx)));
+static tree find_base_decl PARAMS ((tree));
+static alias_set_entry get_alias_set_entry PARAMS ((HOST_WIDE_INT));
+static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, rtx, rtx,
+ int (*) (rtx, int)));
static int aliases_everything_p PARAMS ((rtx));
+static bool nonoverlapping_component_refs_p PARAMS ((tree, tree));
+static tree decl_for_component_ref PARAMS ((tree));
+static rtx adjust_offset_for_component_ref PARAMS ((tree, rtx));
+static int nonoverlapping_memrefs_p PARAMS ((rtx, rtx));
static int write_dependence_p PARAMS ((rtx, rtx, int));
-static int nonlocal_reference_p PARAMS ((rtx));
+
+static int nonlocal_mentioned_p_1 PARAMS ((rtx *, void *));
+static int nonlocal_mentioned_p PARAMS ((rtx));
+static int nonlocal_referenced_p_1 PARAMS ((rtx *, void *));
+static int nonlocal_referenced_p PARAMS ((rtx));
+static int nonlocal_set_p_1 PARAMS ((rtx *, void *));
+static int nonlocal_set_p PARAMS ((rtx));
/* Set up all info needed to perform alias analysis on memory references. */
mems_in_disjoint_alias_sets_p (MEM1, MEM2)
/* Cap the number of passes we make over the insns propagating alias
- information through set chains.
-
- 10 is a completely arbitrary choice. */
+ information through set chains. 10 is a completely arbitrary choice. */
#define MAX_ALIAS_LOOP_PASSES 10
/* reg_base_value[N] gives an address to which register N is related.
static unsigned int reg_base_value_size; /* size of reg_base_value array */
#define REG_BASE_VALUE(X) \
- ((unsigned) REGNO (X) < reg_base_value_size ? reg_base_value[REGNO (X)] : 0)
+ (REGNO (X) < reg_base_value_size \
+ ? reg_base_value[REGNO (X)] : 0)
/* Vector of known invariant relationships between registers. Set in
loop unrolling. Indexed by register number, if nonzero the value
after reload. */
static rtx *alias_invariant;
-/* Vector indexed by N giving the initial (unchanging) value known
- for pseudo-register N. */
+/* Vector indexed by N giving the initial (unchanging) value known for
+ pseudo-register N. This array is initialized in
+ init_alias_analysis, and does not change until end_alias_analysis
+ is called. */
rtx *reg_known_value;
/* Indicates number of valid entries in reg_known_value. */
-static int reg_known_value_size;
+static unsigned int reg_known_value_size;
/* Vector recording for each reg_known_value whether it is due to a
REG_EQUIV note. Future passes (viz., reload) may replace the
pseudo with the equivalent expression and so we account for the
- dependences that would be introduced if that happens. */
-/* ??? This is a problem only on the Convex. The REG_EQUIV notes created in
- assign_parms mention the arg pointer, and there are explicit insns in the
- RTL that modify the arg pointer. Thus we must ensure that such insns don't
- get scheduled across each other because that would invalidate the REG_EQUIV
- notes. One could argue that the REG_EQUIV notes are wrong, but solving
- the problem in the scheduler will likely give better code, so we do it
- here. */
+ dependences that would be introduced if that happens.
+
+ The REG_EQUIV notes created in assign_parms may mention the arg
+ pointer, and there are explicit insns in the RTL that modify the
+ arg pointer. Thus we must ensure that such insns don't get
+ scheduled across each other because that would invalidate the
+ REG_EQUIV notes. One could argue that the REG_EQUIV notes are
+ wrong, but solving the problem in the scheduler will likely give
+ better code, so we do it here. */
char *reg_known_equiv_p;
/* True when scanning insns from the start of the rtl to the
NOTE_INSN_FUNCTION_BEG note. */
-
static int copying_arguments;
/* The splay-tree used to store the various alias set entries. */
-
static splay_tree alias_sets;
-
+\f
/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
such an entry, or NULL otherwise. */
static alias_set_entry
get_alias_set_entry (alias_set)
- int alias_set;
+ HOST_WIDE_INT alias_set;
{
splay_tree_node sn
= splay_tree_lookup (alias_sets, (splay_tree_key) alias_set);
return sn != 0 ? ((alias_set_entry) sn->value) : 0;
}
-/* Returns nonzero value if the alias sets for MEM1 and MEM2 are such
- that the two MEMs cannot alias each other. */
+/* Returns nonzero if the alias sets for MEM1 and MEM2 are such that
+ the two MEMs cannot alias each other. */
static int
mems_in_disjoint_alias_sets_p (mem1, mem2)
rtx mem1;
rtx mem2;
{
- alias_set_entry ase;
-
#ifdef ENABLE_CHECKING
/* Perform a basic sanity check. Namely, that there are no alias sets
if we're not using strict aliasing. This helps to catch bugs
abort ();
#endif
- /* The code used in varargs macros are often not conforming ANSI C,
- which can trick the compiler into making incorrect aliasing
- assumptions in these functions. So, we don't use alias sets in
- such a function. FIXME: This should be moved into the front-end;
- it is a language-dependent notion, and there's no reason not to
- still use these checks to handle globals. */
- if (current_function_stdarg || current_function_varargs)
+ 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
+ record_alias_subset via splay_tree_foreach. */
+
+static int
+insert_subset_children (node, data)
+ splay_tree_node node;
+ void *data;
+{
+ splay_tree_insert ((splay_tree) data, node->key, node->value);
+
+ return 0;
+}
+
+/* Return 1 if the two specified alias sets may conflict. */
+
+int
+alias_sets_conflict_p (set1, set2)
+ HOST_WIDE_INT set1, set2;
+{
+ alias_set_entry ase;
+
+ /* If have no alias set information for one of the operands, we have
+ to assume it can alias anything. */
+ if (set1 == 0 || set2 == 0
+ /* If the two alias sets are the same, they may alias. */
+ || set1 == set2)
+ return 1;
+
+ /* See if the first alias set is a subset of the second. */
+ ase = get_alias_set_entry (set1);
+ if (ase != 0
+ && (ase->has_zero_child
+ || splay_tree_lookup (ase->children,
+ (splay_tree_key) set2)))
+ return 1;
+
+ /* Now do the same, but with the alias sets reversed. */
+ ase = get_alias_set_entry (set2);
+ if (ase != 0
+ && (ase->has_zero_child
+ || splay_tree_lookup (ase->children,
+ (splay_tree_key) set1)))
+ return 1;
+
+ /* The two alias sets are distinct and neither one is the
+ child of the other. Therefore, they cannot alias. */
+ return 0;
+}
+\f
+/* Return 1 if TYPE is a RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE and has
+ has any readonly fields. If any of the fields have types that
+ contain readonly fields, return true as well. */
+
+int
+readonly_fields_p (type)
+ tree type;
+{
+ tree field;
+
+ if (TREE_CODE (type) != RECORD_TYPE && TREE_CODE (type) != UNION_TYPE
+ && TREE_CODE (type) != QUAL_UNION_TYPE)
return 0;
- /* If have no alias set information for one of the MEMs, we have to assume
- it can alias anything. */
- if (MEM_ALIAS_SET (mem1) == 0 || MEM_ALIAS_SET (mem2) == 0)
+ for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
+ if (TREE_CODE (field) == FIELD_DECL
+ && (TREE_READONLY (field)
+ || readonly_fields_p (TREE_TYPE (field))))
+ return 1;
+
+ return 0;
+}
+\f
+/* 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.
+ This is used when allocating temporary storage. If T1 and/or T2 are
+ NULL_TREE, it means we know nothing about the storage. */
+
+int
+objects_must_conflict_p (t1, t2)
+ tree t1, t2;
+{
+ /* 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
+ example the argument and local variables areas of inlined functions. */
+ if (t1 == 0 && t2 == 0)
return 0;
- /* If the two alias sets are the same, they may alias. */
- if (MEM_ALIAS_SET (mem1) == MEM_ALIAS_SET (mem2))
+ /* If one or the other has readonly fields or is readonly,
+ then they may not conflict. */
+ if ((t1 != 0 && readonly_fields_p (t1))
+ || (t2 != 0 && readonly_fields_p (t2))
+ || (t1 != 0 && TYPE_READONLY (t1))
+ || (t2 != 0 && TYPE_READONLY (t2)))
return 0;
- /* Iterate through each of the children of the first alias set,
- comparing it with the second alias set. */
- ase = get_alias_set_entry (MEM_ALIAS_SET (mem1));
- if (ase != 0 && splay_tree_lookup (ase->children,
- (splay_tree_key) MEM_ALIAS_SET (mem2)))
- return 0;
+ /* If they are the same type, they must conflict. */
+ if (t1 == t2
+ /* Likewise if both are volatile. */
+ || (t1 != 0 && TYPE_VOLATILE (t1) && t2 != 0 && TYPE_VOLATILE (t2)))
+ return 1;
- /* Now do the same, but with the alias sets reversed. */
- ase = get_alias_set_entry (MEM_ALIAS_SET (mem2));
- if (ase != 0 && splay_tree_lookup (ase->children,
- (splay_tree_key) MEM_ALIAS_SET (mem1)))
- return 0;
+ /* If one is aggregate and the other is scalar then they may not
+ conflict. */
+ if ((t1 != 0 && AGGREGATE_TYPE_P (t1))
+ != (t2 != 0 && AGGREGATE_TYPE_P (t2)))
+ return 0;
- /* The two MEMs are in distinct alias sets, and neither one is the
- child of the other. Therefore, they cannot alias. */
- return 1;
+ /* Otherwise they conflict only if the alias sets conflict. */
+ return alias_sets_conflict_p (t1 ? get_alias_set (t1) : 0,
+ t2 ? get_alias_set (t2) : 0);
}
+\f
+/* 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'.)
+ If there is no such DECL, or a unique decl cannot be determined,
+ NULL_TREE is returned. */
+
+static tree
+find_base_decl (t)
+ tree t;
+{
+ tree d0, d1, d2;
-/* Insert the NODE into the splay tree given by DATA. Used by
- record_alias_subset via splay_tree_foreach. */
+ if (t == 0 || t == error_mark_node || ! POINTER_TYPE_P (TREE_TYPE (t)))
+ return 0;
-static int
-insert_subset_children (node, data)
- splay_tree_node node;
- void *data;
+ /* If this is a declaration, return it. */
+ if (TREE_CODE_CLASS (TREE_CODE (t)) == 'd')
+ return t;
+
+ /* Handle general expressions. It would be nice to deal with
+ COMPONENT_REFs here. If we could tell that `a' and `b' were the
+ same, then `a->f' and `b->f' are also the same. */
+ switch (TREE_CODE_CLASS (TREE_CODE (t)))
+ {
+ case '1':
+ return find_base_decl (TREE_OPERAND (t, 0));
+
+ case '2':
+ /* Return 0 if found in neither or both are the same. */
+ d0 = find_base_decl (TREE_OPERAND (t, 0));
+ d1 = find_base_decl (TREE_OPERAND (t, 1));
+ if (d0 == d1)
+ return d0;
+ else if (d0 == 0)
+ return d1;
+ else if (d1 == 0)
+ return d0;
+ else
+ return 0;
+
+ case '3':
+ d0 = find_base_decl (TREE_OPERAND (t, 0));
+ d1 = find_base_decl (TREE_OPERAND (t, 1));
+ d2 = find_base_decl (TREE_OPERAND (t, 2));
+
+ /* Set any nonzero values from the last, then from the first. */
+ if (d1 == 0) d1 = d2;
+ if (d0 == 0) d0 = d1;
+ if (d1 == 0) d1 = d0;
+ if (d2 == 0) d2 = d1;
+
+ /* At this point all are nonzero or all are zero. If all three are the
+ same, return it. Otherwise, return zero. */
+ return (d0 == d1 && d1 == d2) ? d0 : 0;
+
+ default:
+ return 0;
+ }
+}
+
+/* Return 1 if all the nested component references handled by
+ get_inner_reference in T are such that we can address the object in T. */
+
+int
+can_address_p (t)
+ tree t;
{
- splay_tree_insert ((splay_tree) data, node->key, node->value);
+ /* If we're at the end, it is vacuously addressable. */
+ if (! handled_component_p (t))
+ return 1;
+
+ /* Bitfields are never addressable. */
+ else if (TREE_CODE (t) == BIT_FIELD_REF)
+ return 0;
+
+ /* Fields are addressable unless they are marked as nonaddressable or
+ the containing type has alias set 0. */
+ else if (TREE_CODE (t) == COMPONENT_REF
+ && ! DECL_NONADDRESSABLE_P (TREE_OPERAND (t, 1))
+ && get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) != 0
+ && can_address_p (TREE_OPERAND (t, 0)))
+ return 1;
+
+ /* Likewise for arrays. */
+ else if ((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF)
+ && ! TYPE_NONALIASED_COMPONENT (TREE_TYPE (TREE_OPERAND (t, 0)))
+ && get_alias_set (TREE_TYPE (TREE_OPERAND (t, 0))) != 0
+ && can_address_p (TREE_OPERAND (t, 0)))
+ return 1;
return 0;
}
+/* Return the alias set for T, which may be either a type or an
+ expression. Call language-specific routine for help, if needed. */
+
+HOST_WIDE_INT
+get_alias_set (t)
+ tree t;
+{
+ HOST_WIDE_INT set;
+
+ /* If we're not doing any alias analysis, just assume everything
+ aliases everything else. Also return 0 if this or its type is
+ an error. */
+ if (! flag_strict_aliasing || t == error_mark_node
+ || (! TYPE_P (t)
+ && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node)))
+ return 0;
+
+ /* We can be passed either an expression or a type. This and the
+ 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
+ that the language may need to handle specially. First handle things that
+ aren't types. */
+ if (! TYPE_P (t))
+ {
+ tree inner = t;
+ tree placeholder_ptr = 0;
+
+ /* Remove any nops, then give the language a chance to do
+ something with this tree before we look at it. */
+ STRIP_NOPS (t);
+ set = (*lang_hooks.get_alias_set) (t);
+ if (set != -1)
+ return set;
+
+ /* First see if the actual object referenced is an INDIRECT_REF from a
+ restrict-qualified pointer or a "void *". Replace
+ PLACEHOLDER_EXPRs. */
+ while (TREE_CODE (inner) == PLACEHOLDER_EXPR
+ || handled_component_p (inner))
+ {
+ if (TREE_CODE (inner) == PLACEHOLDER_EXPR)
+ inner = find_placeholder (inner, &placeholder_ptr);
+ else
+ inner = TREE_OPERAND (inner, 0);
+
+ STRIP_NOPS (inner);
+ }
+
+ /* Check for accesses through restrict-qualified pointers. */
+ if (TREE_CODE (inner) == INDIRECT_REF)
+ {
+ tree decl = find_base_decl (TREE_OPERAND (inner, 0));
+
+ if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
+ {
+ /* If we haven't computed the actual alias set, do it now. */
+ if (DECL_POINTER_ALIAS_SET (decl) == -2)
+ {
+ /* No two restricted pointers can point at the same thing.
+ However, a restricted pointer can point at the same thing
+ as an unrestricted pointer, if that unrestricted pointer
+ is based on the restricted pointer. So, we make the
+ alias set for the restricted pointer a subset of the
+ alias set for the type pointed to by the type of the
+ decl. */
+ HOST_WIDE_INT pointed_to_alias_set
+ = get_alias_set (TREE_TYPE (TREE_TYPE (decl)));
+
+ if (pointed_to_alias_set == 0)
+ /* It's not legal to make a subset of alias set zero. */
+ ;
+ else
+ {
+ DECL_POINTER_ALIAS_SET (decl) = new_alias_set ();
+ record_alias_subset (pointed_to_alias_set,
+ DECL_POINTER_ALIAS_SET (decl));
+ }
+ }
+
+ /* We use the alias set indicated in the declaration. */
+ return DECL_POINTER_ALIAS_SET (decl);
+ }
+
+ /* If we have an INDIRECT_REF via a void pointer, we don't
+ know anything about what that might alias. */
+ else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE)
+ return 0;
+ }
+
+ /* Otherwise, pick up the outermost object that we could have a pointer
+ to, processing conversion and PLACEHOLDER_EXPR as above. */
+ placeholder_ptr = 0;
+ while (TREE_CODE (t) == PLACEHOLDER_EXPR
+ || (handled_component_p (t) && ! can_address_p (t)))
+ {
+ if (TREE_CODE (t) == PLACEHOLDER_EXPR)
+ t = find_placeholder (t, &placeholder_ptr);
+ else
+ t = TREE_OPERAND (t, 0);
+
+ STRIP_NOPS (t);
+ }
+
+ /* If we've already determined the alias set for a decl, just return
+ it. This is necessary for C++ anonymous unions, whose component
+ variables don't look like union members (boo!). */
+ if (TREE_CODE (t) == VAR_DECL
+ && DECL_RTL_SET_P (t) && GET_CODE (DECL_RTL (t)) == MEM)
+ return MEM_ALIAS_SET (DECL_RTL (t));
+
+ /* Now all we care about is the type. */
+ t = TREE_TYPE (t);
+ }
+
+ /* 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. */
+ t = TYPE_MAIN_VARIANT (t);
+ if (TYPE_ALIAS_SET_KNOWN_P (t))
+ return TYPE_ALIAS_SET (t);
+
+ /* See if the language has special handling for this type. */
+ set = (*lang_hooks.get_alias_set) (t);
+ if (set != -1)
+ return set;
+
+ /* 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
+ and references to functions, but that's different.) */
+ else if (TREE_CODE (t) == FUNCTION_TYPE)
+ set = 0;
+ else
+ /* Otherwise make a new alias set for this type. */
+ set = new_alias_set ();
+
+ TYPE_ALIAS_SET (t) = set;
+
+ /* If this is an aggregate type, we must record any component aliasing
+ information. */
+ if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE)
+ record_component_aliases (t);
+
+ return set;
+}
+
+/* Return a brand-new alias set. */
+
+HOST_WIDE_INT
+new_alias_set ()
+{
+ static HOST_WIDE_INT last_alias_set;
+
+ if (flag_strict_aliasing)
+ return ++last_alias_set;
+ else
+ return 0;
+}
+
/* Indicate that things in SUBSET can alias things in SUPERSET, but
not vice versa. For example, in C, a store to an `int' can alias a
structure containing an `int', but not vice versa. Here, the
structure would be the SUPERSET and `int' the SUBSET. This
- function should be called only once per SUPERSET/SUBSET pair. At
- present any given alias set may only be a subset of one superset.
+ function should be called only once per SUPERSET/SUBSET pair.
It is illegal for SUPERSET to be zero; everything is implicitly a
subset of alias set zero. */
void
record_alias_subset (superset, subset)
- int superset;
- int subset;
+ HOST_WIDE_INT superset;
+ HOST_WIDE_INT subset;
{
alias_set_entry superset_entry;
alias_set_entry subset_entry;
+ /* It is possible in complex type situations for both sets to be the same,
+ in which case we can ignore this operation. */
+ if (superset == subset)
+ return;
+
if (superset == 0)
abort ();
superset_entry->alias_set = superset;
superset_entry->children
= splay_tree_new (splay_tree_compare_ints, 0, 0);
+ superset_entry->has_zero_child = 0;
splay_tree_insert (alias_sets, (splay_tree_key) superset,
(splay_tree_value) superset_entry);
+ }
+
+ if (subset == 0)
+ superset_entry->has_zero_child = 1;
+ else
+ {
+ subset_entry = get_alias_set_entry (subset);
+ /* 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 (subset_entry)
+ {
+ if (subset_entry->has_zero_child)
+ superset_entry->has_zero_child = 1;
+
+ splay_tree_foreach (subset_entry->children, insert_subset_children,
+ superset_entry->children);
+ }
+
+ /* Enter the SUBSET itself as a child of the SUPERSET. */
+ splay_tree_insert (superset_entry->children,
+ (splay_tree_key) subset, 0);
+ }
+}
+
+/* Record that component types of TYPE, if any, are part of that type for
+ aliasing purposes. For record types, we only record component types
+ for fields that are marked addressable. For array types, we always
+ record the component types, so the front end should not call this
+ function if the individual component aren't addressable. */
+
+void
+record_component_aliases (type)
+ tree type;
+{
+ HOST_WIDE_INT superset = get_alias_set (type);
+ tree field;
+ if (superset == 0)
+ return;
+
+ switch (TREE_CODE (type))
+ {
+ case ARRAY_TYPE:
+ if (! TYPE_NONALIASED_COMPONENT (type))
+ record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
+ break;
+
+ case RECORD_TYPE:
+ case UNION_TYPE:
+ case QUAL_UNION_TYPE:
+ /* Recursively record aliases for the base classes, if there are any */
+ if (TYPE_BINFO (type) != NULL && TYPE_BINFO_BASETYPES (type) != NULL)
+ {
+ int i;
+ for (i = 0; i < TREE_VEC_LENGTH (TYPE_BINFO_BASETYPES (type)); i++)
+ {
+ tree binfo = TREE_VEC_ELT (TYPE_BINFO_BASETYPES (type), i);
+ record_alias_subset (superset,
+ get_alias_set (BINFO_TYPE (binfo)));
+ }
+ }
+ for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
+ if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field))
+ record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
+ break;
+
+ case COMPLEX_TYPE:
+ record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
+ break;
+
+ default:
+ break;
}
+}
+
+/* Allocate an alias set for use in storing and reading from the varargs
+ spill area. */
+
+HOST_WIDE_INT
+get_varargs_alias_set ()
+{
+ static HOST_WIDE_INT set = -1;
- subset_entry = get_alias_set_entry (subset);
+ if (set == -1)
+ set = new_alias_set ();
- /* 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 (subset_entry)
- splay_tree_foreach (subset_entry->children,
- insert_subset_children,
- superset_entry->children);
+ return set;
+}
+
+/* Likewise, but used for the fixed portions of the frame, e.g., register
+ save areas. */
+
+HOST_WIDE_INT
+get_frame_alias_set ()
+{
+ static HOST_WIDE_INT set = -1;
- /* Enter the SUBSET itself as a child of the SUPERSET. */
- splay_tree_insert (superset_entry->children,
- (splay_tree_key) subset, 0);
+ if (set == -1)
+ set = new_alias_set ();
+
+ return set;
}
/* Inside SRC, the source of a SET, find a base address. */
static rtx
find_base_value (src)
- register rtx src;
+ rtx src;
{
+ unsigned int regno;
+
switch (GET_CODE (src))
{
case SYMBOL_REF:
return src;
case REG:
+ regno = REGNO (src);
/* At the start of a function, argument registers have known base
values which may be lost later. Returning an ADDRESS
expression here allows optimization based on argument values
even when the argument registers are used for other purposes. */
- if (REGNO (src) < FIRST_PSEUDO_REGISTER && copying_arguments)
- return new_reg_base_value[REGNO (src)];
+ if (regno < FIRST_PSEUDO_REGISTER && copying_arguments)
+ return new_reg_base_value[regno];
/* If a pseudo has a known base value, return it. Do not do this
- for hard regs since it can result in a circular dependency
- chain for registers which have values at function entry.
+ for non-fixed hard regs since it can result in a circular
+ dependency chain for registers which have values at function entry.
The test above is not sufficient because the scheduler may move
a copy out of an arg reg past the NOTE_INSN_FUNCTION_BEGIN. */
- if (REGNO (src) >= FIRST_PSEUDO_REGISTER
- && (unsigned) REGNO (src) < reg_base_value_size
- && reg_base_value[REGNO (src)])
- return reg_base_value[REGNO (src)];
+ if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno])
+ && regno < reg_base_value_size
+ && reg_base_value[regno])
+ return reg_base_value[regno];
return src;
if (GET_CODE (src) != PLUS && GET_CODE (src) != MINUS)
break;
- /* ... fall through ... */
+ /* ... fall through ... */
case PLUS:
case MINUS:
{
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
+ is the base. */
+ if (REG_P (src_0) && REG_POINTER (src_0))
+ return find_base_value (src_0);
+ if (REG_P (src_1) && REG_POINTER (src_1))
+ return find_base_value (src_1);
+
/* If either operand is a REG, then see if we already have
a known value for it. */
- if (GET_CODE (src_0) == REG)
+ if (REG_P (src_0))
{
temp = find_base_value (src_0);
if (temp != 0)
src_0 = temp;
}
- if (GET_CODE (src_1) == REG)
+ if (REG_P (src_1))
{
temp = find_base_value (src_1);
if (temp!= 0)
src_1 = temp;
}
+ /* If either base is named object or a special address
+ (like an argument or stack reference), then use it for the
+ base term. */
+ if (src_0 != 0
+ && (GET_CODE (src_0) == SYMBOL_REF
+ || GET_CODE (src_0) == LABEL_REF
+ || (GET_CODE (src_0) == ADDRESS
+ && GET_MODE (src_0) != VOIDmode)))
+ return src_0;
+
+ if (src_1 != 0
+ && (GET_CODE (src_1) == SYMBOL_REF
+ || GET_CODE (src_1) == LABEL_REF
+ || (GET_CODE (src_1) == ADDRESS
+ && GET_MODE (src_1) != VOIDmode)))
+ return src_1;
+
/* Guess which operand is the base address:
If either operand is a symbol, then it is the base. If
either operand is a CONST_INT, then the other is the base. */
else if (GET_CODE (src_0) == CONST_INT || CONSTANT_P (src_1))
return find_base_value (src_1);
- /* This might not be necessary anymore:
- If either operand is a REG that is a known pointer, then it
- is the base. */
- else if (GET_CODE (src_0) == REG && REGNO_POINTER_FLAG (REGNO (src_0)))
- return find_base_value (src_0);
- else if (GET_CODE (src_1) == REG && REGNO_POINTER_FLAG (REGNO (src_1)))
- return find_base_value (src_1);
-
return 0;
}
case AND:
/* 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)
return find_base_value (XEXP (src, 0));
return 0;
- case ZERO_EXTEND:
- case SIGN_EXTEND: /* used for NT/Alpha pointers */
+ case TRUNCATE:
+ if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode))
+ break;
+ /* Fall through. */
case HIGH:
+ case PRE_INC:
+ case PRE_DEC:
+ case POST_INC:
+ case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
return find_base_value (XEXP (src, 0));
+ case ZERO_EXTEND:
+ case SIGN_EXTEND: /* used for NT/Alpha pointers */
+ {
+ rtx temp = find_base_value (XEXP (src, 0));
+
+#ifdef POINTERS_EXTEND_UNSIGNED
+ if (temp != 0 && CONSTANT_P (temp) && GET_MODE (temp) != Pmode)
+ temp = convert_memory_address (Pmode, temp);
+#endif
+
+ return temp;
+ }
+
default:
break;
}
rtx dest, set;
void *data ATTRIBUTE_UNUSED;
{
- register unsigned regno;
+ unsigned regno;
rtx src;
if (GET_CODE (dest) != REG)
switch (GET_CODE (src))
{
case LO_SUM:
- case PLUS:
case MINUS:
if (XEXP (src, 0) != dest && XEXP (src, 1) != dest)
new_reg_base_value[regno] = 0;
break;
+ case PLUS:
+ /* 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
+ an index. */
+ {
+ rtx other = NULL_RTX;
+
+ if (XEXP (src, 0) == dest)
+ other = XEXP (src, 1);
+ else if (XEXP (src, 1) == dest)
+ other = XEXP (src, 0);
+
+ if (! other || find_base_value (other))
+ new_reg_base_value[regno] = 0;
+ break;
+ }
case AND:
if (XEXP (src, 0) != dest || GET_CODE (XEXP (src, 1)) != CONST_INT)
new_reg_base_value[regno] = 0;
reg_seen[regno] = 1;
}
-/* Called from loop optimization when a new pseudo-register is created. */
+/* Called from loop optimization when a new pseudo-register is
+ created. It indicates that REGNO is being set to VAL. f INVARIANT
+ is true then this value also describes an invariant relationship
+ which can be used to deduce that two registers with unknown values
+ are different. */
void
record_base_value (regno, val, invariant)
- int regno;
+ unsigned int regno;
rtx val;
int invariant;
{
- if ((unsigned) regno >= reg_base_value_size)
+ if (regno >= reg_base_value_size)
return;
- /* If INVARIANT is true then this value also describes an invariant
- relationship which can be used to deduce that two registers with
- unknown values are different. */
if (invariant && alias_invariant)
alias_invariant[regno] = val;
if (GET_CODE (val) == REG)
{
- if ((unsigned) REGNO (val) < reg_base_value_size)
+ if (REGNO (val) < reg_base_value_size)
reg_base_value[regno] = reg_base_value[REGNO (val)];
return;
reg_base_value[regno] = find_base_value (val);
}
-static rtx
+/* 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
+ optimizations. We don't need to clear reg_base_value, since flow only
+ changes the offset. */
+
+void
+clear_reg_alias_info (reg)
+ rtx reg;
+{
+ unsigned int regno = REGNO (reg);
+
+ if (regno < reg_known_value_size && regno >= FIRST_PSEUDO_REGISTER)
+ reg_known_value[regno] = reg;
+}
+
+/* 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,
+ and the register has a known value (say a SYMBOL_REF), then a MEM
+ whose address is the SYMBOL_REF is returned.) */
+
+rtx
canon_rtx (x)
rtx x;
{
if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1))
{
- /* We can tolerate LO_SUMs being offset here; these
- rtl are used for nothing other than comparisons. */
if (GET_CODE (x0) == CONST_INT)
- return plus_constant_for_output (x1, INTVAL (x0));
+ return plus_constant (x1, INTVAL (x0));
else if (GET_CODE (x1) == CONST_INT)
- return plus_constant_for_output (x0, INTVAL (x1));
+ return plus_constant (x0, INTVAL (x1));
return gen_rtx_PLUS (GET_MODE (x), x0, x1);
}
}
MEM alone, but need to return the canonicalized MEM with
all the flags with their original values. */
else if (GET_CODE (x) == MEM)
- {
- rtx addr = canon_rtx (XEXP (x, 0));
-
- if (addr != XEXP (x, 0))
- {
- rtx new = gen_rtx_MEM (GET_MODE (x), addr);
+ x = replace_equiv_address_nv (x, canon_rtx (XEXP (x, 0)));
- RTX_UNCHANGING_P (new) = RTX_UNCHANGING_P (x);
- MEM_COPY_ATTRIBUTES (new, x);
- MEM_ALIAS_SET (new) = MEM_ALIAS_SET (x);
- x = new;
- }
- }
return x;
}
rtx_equal_for_memref_p (x, y)
rtx x, y;
{
- register int i;
- register int j;
- register enum rtx_code code;
- register const char *fmt;
+ int i;
+ int j;
+ enum rtx_code code;
+ const char *fmt;
if (x == 0 && y == 0)
return 1;
if (GET_MODE (x) != GET_MODE (y))
return 0;
- /* REG, LABEL_REF, and SYMBOL_REF can be compared nonrecursively. */
-
- if (code == REG)
- return REGNO (x) == REGNO (y);
- if (code == LABEL_REF)
- return XEXP (x, 0) == XEXP (y, 0);
- if (code == SYMBOL_REF)
- return XSTR (x, 0) == XSTR (y, 0);
- if (code == CONST_INT)
- return INTVAL (x) == INTVAL (y);
- /* There's no need to compare the contents of CONST_DOUBLEs because
- they're unique. */
- if (code == CONST_DOUBLE)
- return 0;
- if (code == ADDRESSOF)
- return (REGNO (XEXP (x, 0)) == REGNO (XEXP (y, 0))
- && XINT (x, 1) == XINT (y, 1));
+ /* Some RTL can be compared without a recursive examination. */
+ switch (code)
+ {
+ case VALUE:
+ return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y);
+
+ case REG:
+ return REGNO (x) == REGNO (y);
+
+ case LABEL_REF:
+ return XEXP (x, 0) == XEXP (y, 0);
+
+ case SYMBOL_REF:
+ return XSTR (x, 0) == XSTR (y, 0);
+
+ case CONST_INT:
+ case CONST_DOUBLE:
+ /* There's no need to compare the contents of CONST_DOUBLEs or
+ CONST_INTs because pointer equality is a good enough
+ comparison for these nodes. */
+ return 0;
+
+ case ADDRESSOF:
+ return (XINT (x, 1) == XINT (y, 1)
+ && rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)));
+
+ default:
+ break;
+ }
/* For commutative operations, the RTX match if the operand match in any
order. Also handle the simple binary and unary cases without a loop. */
return 0;
break;
+ /* This can happen for asm operands. */
+ case 's':
+ if (strcmp (XSTR (x, i), XSTR (y, i)))
+ return 0;
+ break;
+
/* This can happen for an asm which clobbers memory. */
case '0':
break;
find_symbolic_term (x)
rtx x;
{
- register int i;
- register enum rtx_code code;
- register const char *fmt;
+ int i;
+ enum rtx_code code;
+ const char *fmt;
code = GET_CODE (x);
if (code == SYMBOL_REF || code == LABEL_REF)
static rtx
find_base_term (x)
- register rtx x;
+ rtx x;
{
+ cselib_val *val;
+ struct elt_loc_list *l;
+
+#if defined (FIND_BASE_TERM)
+ /* Try machine-dependent ways to find the base term. */
+ x = FIND_BASE_TERM (x);
+#endif
+
switch (GET_CODE (x))
{
case REG:
return REG_BASE_VALUE (x);
- case ZERO_EXTEND:
- case SIGN_EXTEND: /* Used for Alpha/NT pointers */
+ case TRUNCATE:
+ if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode))
+ return 0;
+ /* Fall through. */
case HIGH:
case PRE_INC:
case PRE_DEC:
case POST_INC:
case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
return find_base_term (XEXP (x, 0));
+ case ZERO_EXTEND:
+ case SIGN_EXTEND: /* Used for Alpha/NT pointers */
+ {
+ rtx temp = find_base_term (XEXP (x, 0));
+
+#ifdef POINTERS_EXTEND_UNSIGNED
+ if (temp != 0 && CONSTANT_P (temp) && GET_MODE (temp) != Pmode)
+ temp = convert_memory_address (Pmode, temp);
+#endif
+
+ return temp;
+ }
+
+ case VALUE:
+ val = CSELIB_VAL_PTR (x);
+ for (l = val->locs; l; l = l->next)
+ if ((x = find_base_term (l->loc)) != 0)
+ return x;
+ return 0;
+
case CONST:
x = XEXP (x, 0);
if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS)
rtx tmp1 = XEXP (x, 0);
rtx tmp2 = XEXP (x, 1);
- /* This is a litle 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
routine may return the index register instead of the base register.
is a shift or multiply, then it must be the index register and the
other operand is the base register. */
+ if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2))
+ return find_base_term (tmp2);
+
/* If either operand is known to be a pointer, then use it
to determine the base term. */
- if (REG_P (tmp1) && REGNO_POINTER_FLAG (REGNO (tmp1)))
+ if (REG_P (tmp1) && REG_POINTER (tmp1))
return find_base_term (tmp1);
- if (REG_P (tmp2) && REGNO_POINTER_FLAG (REGNO (tmp2)))
+ if (REG_P (tmp2) && REG_POINTER (tmp2))
return find_base_term (tmp2);
/* Neither operand was known to be a pointer. Go ahead and find the
}
case AND:
- if (GET_CODE (XEXP (x, 0)) == REG && GET_CODE (XEXP (x, 1)) == CONST_INT)
- return REG_BASE_VALUE (XEXP (x, 0));
+ if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) != 0)
+ return find_base_term (XEXP (x, 0));
return 0;
case SYMBOL_REF:
case LABEL_REF:
return x;
+ case ADDRESSOF:
+ return REG_BASE_VALUE (frame_pointer_rtx);
+
default:
return 0;
}
return 1;
if (GET_CODE (x) == AND
&& (GET_CODE (XEXP (x, 1)) != CONST_INT
- || GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1))))
+ || (int) GET_MODE_UNIT_SIZE (y_mode) < -INTVAL (XEXP (x, 1))))
return 1;
if (GET_CODE (y) == AND
&& (GET_CODE (XEXP (y, 1)) != CONST_INT
- || GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1))))
+ || (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1))))
return 1;
/* Differing symbols never alias. */
return 0;
if (flag_argument_noalias > 1)
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 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
- is not modified by the memory reference then ADDR is returned. */
+/* 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
+ a more useful rtx. */
+
+rtx
+get_addr (x)
+ rtx x;
+{
+ cselib_val *v;
+ struct elt_loc_list *l;
+
+ if (GET_CODE (x) != VALUE)
+ return x;
+ v = CSELIB_VAL_PTR (x);
+ for (l = v->locs; l; l = l->next)
+ if (CONSTANT_P (l->loc))
+ return l->loc;
+ for (l = v->locs; l; l = l->next)
+ if (GET_CODE (l->loc) != REG && GET_CODE (l->loc) != MEM)
+ return l->loc;
+ if (v->locs)
+ return v->locs->loc;
+ return x;
+}
+
+/* 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
+ is not modified by the memory reference then ADDR is returned. */
rtx
addr_side_effect_eval (addr, size, n_refs)
Nice to notice that varying addresses cannot conflict with fp if no
local variables had their addresses taken, but that's too hard now. */
-
static int
memrefs_conflict_p (xsize, x, ysize, y, c)
- register rtx x, y;
+ rtx x, y;
int xsize, ysize;
HOST_WIDE_INT c;
{
+ if (GET_CODE (x) == VALUE)
+ x = get_addr (x);
+ if (GET_CODE (y) == VALUE)
+ y = get_addr (y);
if (GET_CODE (x) == HIGH)
x = XEXP (x, 0);
else if (GET_CODE (x) == LO_SUM)
return memrefs_conflict_p (xsize, x, ysize, XEXP (y, 0), c);
}
+ if (GET_CODE (x) == ADDRESSOF)
+ {
+ if (y == frame_pointer_rtx
+ || GET_CODE (y) == ADDRESSOF)
+ return xsize <= 0 || ysize <= 0;
+ }
+ if (GET_CODE (y) == ADDRESSOF)
+ {
+ if (x == frame_pointer_rtx)
+ return xsize <= 0 || ysize <= 0;
+ }
+
if (CONSTANT_P (x))
{
if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT)
canon_rtx (XEXP (y, 0)), c);
if (CONSTANT_P (y))
- return (xsize < 0 || ysize < 0
+ return (xsize <= 0 || ysize <= 0
|| (rtx_equal_for_memref_p (x, y)
- && (xsize == 0 || ysize == 0
- || (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))));
+ && ((c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))));
return 1;
}
changed. A volatile and non-volatile reference can be interchanged
though.
- A MEM_IN_STRUCT reference at a non-QImode non-AND varying address can never
- conflict with a non-MEM_IN_STRUCT reference at a fixed address. We must
- allow QImode aliasing because the ANSI C standard allows character
- pointers to alias anything. We are assuming that characters are
- always QImode here. We also must allow AND addresses, because they may
- generate accesses outside the object being referenced. This is used to
- generate aligned addresses from unaligned addresses, for instance, the
- alpha storeqi_unaligned pattern. */
+ 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
+ also must allow AND addresses, because they may generate accesses
+ outside the object being referenced. This is used to generate
+ aligned addresses from unaligned addresses, for instance, the alpha
+ storeqi_unaligned pattern. */
/* Read dependence: X is read after read in MEM takes place. There can
only be a dependence here if both reads are volatile. */
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
to decide whether or not an address may vary; it should return
- nozero whenever variation is possible. */
-
-static rtx
-fixed_scalar_and_varying_struct_p (mem1, mem2, varies_p)
- rtx mem1;
- rtx mem2;
- int (*varies_p) PARAMS ((rtx));
-{
- rtx mem1_addr = XEXP (mem1, 0);
- rtx mem2_addr = XEXP (mem2, 0);
+ nonzero whenever variation is possible.
+ MEM1_ADDR and MEM2_ADDR are the addresses of MEM1 and MEM2. */
+static rtx
+fixed_scalar_and_varying_struct_p (mem1, mem2, mem1_addr, mem2_addr, varies_p)
+ rtx mem1, mem2;
+ rtx mem1_addr, mem2_addr;
+ int (*varies_p) PARAMS ((rtx, int));
+{
+ if (! flag_strict_aliasing)
+ return NULL_RTX;
+
if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2)
- && !varies_p (mem1_addr) && varies_p (mem2_addr))
+ && !varies_p (mem1_addr, 1) && varies_p (mem2_addr, 1))
/* MEM1 is a scalar at a fixed address; MEM2 is a struct at a
varying address. */
return mem1;
if (MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2)
- && varies_p (mem1_addr) && !varies_p (mem2_addr))
+ && varies_p (mem1_addr, 1) && !varies_p (mem2_addr, 1))
/* MEM2 is a scalar at a fixed address; MEM1 is a struct at a
varying address. */
return mem2;
aliases_everything_p (mem)
rtx mem;
{
- if (GET_MODE (mem) == QImode)
- /* ANSI C says that a `char*' can point to anything. */
- return 1;
-
if (GET_CODE (XEXP (mem, 0)) == AND)
/* If the address is an AND, its very hard to know at what it is
actually pointing. */
return 0;
}
+/* Return true if we can determine that the fields referenced cannot
+ overlap for any pair of objects. */
+
+static bool
+nonoverlapping_component_refs_p (x, y)
+ tree x, y;
+{
+ tree fieldx, fieldy, typex, typey, orig_y;
+
+ do
+ {
+ /* The comparison has to be done at a common type, since we don't
+ know how the inheritance hierarchy works. */
+ orig_y = y;
+ do
+ {
+ fieldx = TREE_OPERAND (x, 1);
+ typex = DECL_FIELD_CONTEXT (fieldx);
+
+ y = orig_y;
+ do
+ {
+ fieldy = TREE_OPERAND (y, 1);
+ typey = DECL_FIELD_CONTEXT (fieldy);
+
+ if (typex == typey)
+ goto found;
+
+ y = TREE_OPERAND (y, 0);
+ }
+ while (y && TREE_CODE (y) == COMPONENT_REF);
+
+ x = TREE_OPERAND (x, 0);
+ }
+ while (x && TREE_CODE (x) == COMPONENT_REF);
+
+ /* Never found a common type. */
+ return false;
+
+ found:
+ /* If we're left with accessing different fields of a structure,
+ then no overlap. */
+ if (TREE_CODE (typex) == RECORD_TYPE
+ && fieldx != fieldy)
+ return true;
+
+ /* The comparison on the current field failed. If we're accessing
+ a very nested structure, look at the next outer level. */
+ x = TREE_OPERAND (x, 0);
+ y = TREE_OPERAND (y, 0);
+ }
+ while (x && y
+ && TREE_CODE (x) == COMPONENT_REF
+ && TREE_CODE (y) == COMPONENT_REF);
+
+ return false;
+}
+
+/* Look at the bottom of the COMPONENT_REF list for a DECL, and return it. */
+
+static tree
+decl_for_component_ref (x)
+ tree x;
+{
+ do
+ {
+ x = TREE_OPERAND (x, 0);
+ }
+ while (x && TREE_CODE (x) == COMPONENT_REF);
+
+ return x && DECL_P (x) ? x : NULL_TREE;
+}
+
+/* Walk up the COMPONENT_REF list and adjust OFFSET to compensate for the
+ offset of the field reference. */
+
+static rtx
+adjust_offset_for_component_ref (x, offset)
+ tree x;
+ rtx offset;
+{
+ HOST_WIDE_INT ioffset;
+
+ if (! offset)
+ return NULL_RTX;
+
+ ioffset = INTVAL (offset);
+ do
+ {
+ tree field = TREE_OPERAND (x, 1);
+
+ if (! host_integerp (DECL_FIELD_OFFSET (field), 1))
+ return NULL_RTX;
+ ioffset += (tree_low_cst (DECL_FIELD_OFFSET (field), 1)
+ + (tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1)
+ / BITS_PER_UNIT));
+
+ x = TREE_OPERAND (x, 0);
+ }
+ while (x && TREE_CODE (x) == COMPONENT_REF);
+
+ return GEN_INT (ioffset);
+}
+
+/* Return nonzero if we can deterimine the exprs corresponding to memrefs
+ X and Y and they do not overlap. */
+
+static int
+nonoverlapping_memrefs_p (x, y)
+ rtx x, y;
+{
+ tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);
+ rtx rtlx, rtly;
+ rtx basex, basey;
+ rtx moffsetx, moffsety;
+ HOST_WIDE_INT offsetx = 0, offsety = 0, sizex, sizey, tem;
+
+ /* Unless both have exprs, we can't tell anything. */
+ if (exprx == 0 || expry == 0)
+ return 0;
+
+ /* If both are field references, we may be able to determine something. */
+ if (TREE_CODE (exprx) == COMPONENT_REF
+ && TREE_CODE (expry) == COMPONENT_REF
+ && nonoverlapping_component_refs_p (exprx, expry))
+ return 1;
+
+ /* If the field reference test failed, look at the DECLs involved. */
+ moffsetx = MEM_OFFSET (x);
+ if (TREE_CODE (exprx) == COMPONENT_REF)
+ {
+ tree t = decl_for_component_ref (exprx);
+ if (! t)
+ return 0;
+ moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
+ exprx = t;
+ }
+ moffsety = MEM_OFFSET (y);
+ if (TREE_CODE (expry) == COMPONENT_REF)
+ {
+ tree t = decl_for_component_ref (expry);
+ if (! t)
+ return 0;
+ moffsety = adjust_offset_for_component_ref (expry, moffsety);
+ expry = t;
+ }
+
+ if (! DECL_P (exprx) || ! DECL_P (expry))
+ return 0;
+
+ rtlx = DECL_RTL (exprx);
+ rtly = DECL_RTL (expry);
+
+ /* 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
+ of the stack frame used for locals for spilled pseudos. */
+ if ((GET_CODE (rtlx) != MEM || GET_CODE (rtly) != MEM)
+ && ! rtx_equal_p (rtlx, rtly))
+ return 1;
+
+ /* 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
+ we can avoid overlap is if we can deduce that they are nonoverlapping
+ pieces of that decl, which is very rare. */
+ basex = GET_CODE (rtlx) == MEM ? XEXP (rtlx, 0) : rtlx;
+ if (GET_CODE (basex) == PLUS && GET_CODE (XEXP (basex, 1)) == CONST_INT)
+ offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0);
+
+ basey = GET_CODE (rtly) == MEM ? XEXP (rtly, 0) : rtly;
+ if (GET_CODE (basey) == PLUS && GET_CODE (XEXP (basey, 1)) == CONST_INT)
+ offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0);
+
+ /* 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
+ stack frame. Otherwise a different base means we can't tell if they
+ overlap or not. */
+ if (! rtx_equal_p (basex, basey))
+ return ((CONSTANT_P (basex) && CONSTANT_P (basey))
+ || (CONSTANT_P (basex) && REG_P (basey)
+ && REGNO_PTR_FRAME_P (REGNO (basey)))
+ || (CONSTANT_P (basey) && REG_P (basex)
+ && REGNO_PTR_FRAME_P (REGNO (basex))));
+
+ sizex = (GET_CODE (rtlx) != MEM ? (int) GET_MODE_SIZE (GET_MODE (rtlx))
+ : MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx))
+ : -1);
+ sizey = (GET_CODE (rtly) != MEM ? (int) GET_MODE_SIZE (GET_MODE (rtly))
+ : MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) :
+ -1);
+
+ /* If we have an offset for either memref, it can update the values computed
+ above. */
+ if (moffsetx)
+ offsetx += INTVAL (moffsetx), sizex -= INTVAL (moffsetx);
+ if (moffsety)
+ offsety += INTVAL (moffsety), sizey -= INTVAL (moffsety);
+
+ /* 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
+ memref as being anywhere inside the DECL's MEM. */
+ if (MEM_SIZE (x) && moffsetx)
+ sizex = INTVAL (MEM_SIZE (x));
+ if (MEM_SIZE (y) && moffsety)
+ sizey = INTVAL (MEM_SIZE (y));
+
+ /* Put the values of the memref with the lower offset in X's values. */
+ if (offsetx > offsety)
+ {
+ tem = offsetx, offsetx = offsety, offsety = tem;
+ tem = sizex, sizex = sizey, sizey = tem;
+ }
+
+ /* If we don't know the size of the lower-offset value, we can't tell
+ if they conflict. Otherwise, we do the test. */
+ return sizex >= 0 && offsety > offsetx + sizex;
+}
+
/* True dependence: X is read after store in MEM takes place. */
int
rtx mem;
enum machine_mode mem_mode;
rtx x;
- int (*varies) PARAMS ((rtx));
+ int (*varies) PARAMS ((rtx, int));
{
- register rtx x_addr, mem_addr;
+ rtx x_addr, mem_addr;
+ rtx base;
+
+ if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
+ return 1;
+
+ if (DIFFERENT_ALIAS_SETS_P (x, mem))
+ return 0;
+
+ /* Unchanging memory can't conflict with non-unchanging memory.
+ A non-unchanging read can conflict with a non-unchanging write.
+ An unchanging read can conflict with an unchanging write since
+ there may be a single store to this address to initialize it.
+ Note that an unchanging store can conflict with a non-unchanging read
+ since we have to make conservative assumptions when we have a
+ record with readonly fields and we are copying the whole thing.
+ Just fall through to the code below to resolve potential conflicts.
+ This won't handle all cases optimally, but the possible performance
+ loss should be negligible. */
+ if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
+ return 0;
+
+ if (nonoverlapping_memrefs_p (mem, x))
+ return 0;
+
+ if (mem_mode == VOIDmode)
+ mem_mode = GET_MODE (mem);
+
+ x_addr = get_addr (XEXP (x, 0));
+ mem_addr = get_addr (XEXP (mem, 0));
+
+ base = find_base_term (x_addr);
+ if (base && (GET_CODE (base) == LABEL_REF
+ || (GET_CODE (base) == SYMBOL_REF
+ && CONSTANT_POOL_ADDRESS_P (base))))
+ return 0;
+
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
+ return 0;
+
+ x_addr = canon_rtx (x_addr);
+ mem_addr = canon_rtx (mem_addr);
+
+ if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
+ SIZE_FOR_MODE (x), x_addr, 0))
+ return 0;
+
+ if (aliases_everything_p (x))
+ return 1;
+
+ /* We cannot use aliases_everything_p to test MEM, since we must look
+ at MEM_MODE, rather than GET_MODE (MEM). */
+ if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
+ return 1;
+
+ /* In true_dependence we also allow BLKmode to alias anything. Why
+ don't we do this in anti_dependence and output_dependence? */
+ if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
+ return 1;
+
+ return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
+ varies);
+}
+
+/* Canonical true dependence: X is read after store in MEM takes place.
+ Variant of true_dependence which assumes MEM has already been
+ canonicalized (hence we no longer do that here).
+ The mem_addr argument has been added, since true_dependence computed
+ this value prior to canonicalizing. */
+
+int
+canon_true_dependence (mem, mem_mode, mem_addr, x, varies)
+ rtx mem, mem_addr, x;
+ enum machine_mode mem_mode;
+ int (*varies) PARAMS ((rtx, int));
+{
+ rtx x_addr;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
return 0;
- if (mem_mode == VOIDmode)
- mem_mode = GET_MODE (mem);
-
- if (! base_alias_check (XEXP (x, 0), XEXP (mem, 0), GET_MODE (x), mem_mode))
+ if (nonoverlapping_memrefs_p (x, mem))
return 0;
- x_addr = canon_rtx (XEXP (x, 0));
- mem_addr = canon_rtx (XEXP (mem, 0));
+ x_addr = get_addr (XEXP (x, 0));
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
+ return 0;
+
+ x_addr = canon_rtx (x_addr);
if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
SIZE_FOR_MODE (x), x_addr, 0))
return 0;
if (aliases_everything_p (x))
return 1;
- /* We cannot use aliases_everyting_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). */
if (mem_mode == QImode || GET_CODE (mem_addr) == AND)
return 1;
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
return 1;
- return !fixed_scalar_and_varying_struct_p (mem, x, varies);
+ return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
+ varies);
}
/* Returns non-zero if a write to X might alias a previous read from
{
rtx x_addr, mem_addr;
rtx fixed_scalar;
+ rtx base;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
+ if (DIFFERENT_ALIAS_SETS_P (x, mem))
+ return 0;
+
+ /* Unchanging memory can't conflict with non-unchanging memory. */
+ if (RTX_UNCHANGING_P (x) != RTX_UNCHANGING_P (mem))
+ return 0;
+
/* If MEM is an unchanging read, then it can't possibly conflict with
the store to X, because there is at most one store to MEM, and it must
have occurred somewhere before MEM. */
- if (!writep && RTX_UNCHANGING_P (mem))
+ if (! writep && RTX_UNCHANGING_P (mem))
return 0;
- if (! base_alias_check (XEXP (x, 0), XEXP (mem, 0), GET_MODE (x),
- GET_MODE (mem)))
+ if (nonoverlapping_memrefs_p (x, mem))
return 0;
- x = canon_rtx (x);
- mem = canon_rtx (mem);
+ x_addr = get_addr (XEXP (x, 0));
+ mem_addr = get_addr (XEXP (mem, 0));
- if (DIFFERENT_ALIAS_SETS_P (x, mem))
+ if (! writep)
+ {
+ base = find_base_term (mem_addr);
+ if (base && (GET_CODE (base) == LABEL_REF
+ || (GET_CODE (base) == SYMBOL_REF
+ && CONSTANT_POOL_ADDRESS_P (base))))
+ return 0;
+ }
+
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x),
+ GET_MODE (mem)))
return 0;
- x_addr = XEXP (x, 0);
- mem_addr = XEXP (mem, 0);
+ x_addr = canon_rtx (x_addr);
+ mem_addr = canon_rtx (mem_addr);
if (!memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr,
SIZE_FOR_MODE (x), x_addr, 0))
return 0;
fixed_scalar
- = fixed_scalar_and_varying_struct_p (mem, x, rtx_addr_varies_p);
-
+ = fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
+ rtx_addr_varies_p);
+
return (!(fixed_scalar == mem && !aliases_everything_p (x))
&& !(fixed_scalar == x && !aliases_everything_p (mem)));
}
int
output_dependence (mem, x)
- register rtx mem;
- register rtx x;
+ rtx mem;
+ rtx x;
{
return write_dependence_p (mem, x, /*writep=*/1);
}
-
-/* Returns non-zero if X might refer to something which is not
- local to the function and is not constant. */
+\f
+/* A subroutine of nonlocal_mentioned_p, returns 1 if *LOC mentions
+ something which is not local to the function and is not constant. */
static int
-nonlocal_reference_p (x)
- rtx x;
+nonlocal_mentioned_p_1 (loc, data)
+ rtx *loc;
+ void *data ATTRIBUTE_UNUSED;
{
+ rtx x = *loc;
rtx base;
- register RTX_CODE code;
int regno;
- code = GET_CODE (x);
-
- if (GET_RTX_CLASS (code) == 'i')
- {
- /* Constant functions are constant. */
- if (code == CALL_INSN && CONST_CALL_P (x))
- return 0;
- x = PATTERN (x);
- code = GET_CODE (x);
- }
+ if (! x)
+ return 0;
- switch (code)
+ switch (GET_CODE (x))
{
case SUBREG:
if (GET_CODE (SUBREG_REG (x)) == REG)
{
/* Global registers are not local. */
if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER
- && global_regs[REGNO (SUBREG_REG (x)) + SUBREG_WORD (x)])
+ && global_regs[subreg_regno (x)])
return 1;
return 0;
}
case CC0:
case CONST_INT:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case CONST:
case LABEL_REF:
return 0;
return 1;
case CALL:
- /* Recursion introduces no additional considerations. */
- if (GET_CODE (XEXP (x, 0)) == MEM
- && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
- && strcmp(XSTR (XEXP (XEXP (x, 0), 0), 0),
- IDENTIFIER_POINTER (
- DECL_ASSEMBLER_NAME (current_function_decl))) == 0)
- return 0;
+ /* Non-constant calls and recursion are not local. */
return 1;
case MEM:
}
return 1;
+ case UNSPEC_VOLATILE:
case ASM_INPUT:
+ return 1;
+
case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 1;
+
+ /* FALLTHROUGH */
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+/* Returns non-zero if X might mention something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_mentioned_p (x)
+ rtx x;
+{
+
+ if (INSN_P (x))
+ {
+ if (GET_CODE (x) == CALL_INSN)
+ {
+ if (! CONST_OR_PURE_CALL_P (x))
+ return 1;
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
+ }
+
+ return for_each_rtx (&x, nonlocal_mentioned_p_1, NULL);
+}
+
+/* A subroutine of nonlocal_referenced_p, returns 1 if *LOC references
+ something which is not local to the function and is not constant. */
+
+static int
+nonlocal_referenced_p_1 (loc, data)
+ rtx *loc;
+ void *data ATTRIBUTE_UNUSED;
+{
+ rtx x = *loc;
+
+ if (! x)
+ return 0;
+
+ switch (GET_CODE (x))
+ {
+ case MEM:
+ case REG:
+ case SYMBOL_REF:
+ case SUBREG:
+ return nonlocal_mentioned_p (x);
+
+ case CALL:
+ /* Non-constant calls and recursion are not local. */
+ return 1;
+
+ case SET:
+ if (nonlocal_mentioned_p (SET_SRC (x)))
+ return 1;
+
+ if (GET_CODE (SET_DEST (x)) == MEM)
+ return nonlocal_mentioned_p (XEXP (SET_DEST (x), 0));
+
+ /* If the destination is anything other than a CC0, PC,
+ MEM, REG, or a SUBREG of a REG that occupies all of
+ the REG, then X references nonlocal memory if it is
+ mentioned in the destination. */
+ if (GET_CODE (SET_DEST (x)) != CC0
+ && GET_CODE (SET_DEST (x)) != PC
+ && GET_CODE (SET_DEST (x)) != REG
+ && ! (GET_CODE (SET_DEST (x)) == SUBREG
+ && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG
+ && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (SET_DEST (x))))
+ + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
+ == ((GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
+ + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
+ return nonlocal_mentioned_p (SET_DEST (x));
+ return 0;
+
+ case CLOBBER:
+ if (GET_CODE (XEXP (x, 0)) == MEM)
+ return nonlocal_mentioned_p (XEXP (XEXP (x, 0), 0));
+ return 0;
+
+ case USE:
+ return nonlocal_mentioned_p (XEXP (x, 0));
+
+ case ASM_INPUT:
+ case UNSPEC_VOLATILE:
return 1;
+ case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 1;
+
+ /* FALLTHROUGH */
+
default:
break;
}
- /* Recursively scan the operands of this expression. */
+ return 0;
+}
- {
- register const char *fmt = GET_RTX_FORMAT (code);
- register int i;
-
- for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
- {
- if (fmt[i] == 'e')
- {
- if (nonlocal_reference_p (XEXP (x, i)))
- return 1;
- }
- else if (fmt[i] == 'E')
- {
- register int j;
- for (j = 0; j < XVECLEN (x, i); j++)
- if (nonlocal_reference_p (XVECEXP (x, i, j)))
- return 1;
- }
- }
- }
+/* Returns non-zero if X might reference something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_referenced_p (x)
+ rtx x;
+{
+
+ if (INSN_P (x))
+ {
+ if (GET_CODE (x) == CALL_INSN)
+ {
+ if (! CONST_OR_PURE_CALL_P (x))
+ return 1;
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
+ }
+
+ return for_each_rtx (&x, nonlocal_referenced_p_1, NULL);
+}
+
+/* A subroutine of nonlocal_set_p, returns 1 if *LOC sets
+ something which is not local to the function and is not constant. */
+
+static int
+nonlocal_set_p_1 (loc, data)
+ rtx *loc;
+ void *data ATTRIBUTE_UNUSED;
+{
+ rtx x = *loc;
+
+ if (! x)
+ return 0;
+
+ switch (GET_CODE (x))
+ {
+ case CALL:
+ /* Non-constant calls and recursion are not local. */
+ return 1;
+
+ case PRE_INC:
+ case PRE_DEC:
+ case POST_INC:
+ case POST_DEC:
+ case PRE_MODIFY:
+ case POST_MODIFY:
+ return nonlocal_mentioned_p (XEXP (x, 0));
+
+ case SET:
+ if (nonlocal_mentioned_p (SET_DEST (x)))
+ return 1;
+ return nonlocal_set_p (SET_SRC (x));
+
+ case CLOBBER:
+ return nonlocal_mentioned_p (XEXP (x, 0));
+
+ case USE:
+ return 0;
+
+ case ASM_INPUT:
+ case UNSPEC_VOLATILE:
+ return 1;
+
+ case ASM_OPERANDS:
+ if (MEM_VOLATILE_P (x))
+ return 1;
+
+ /* FALLTHROUGH */
+
+ default:
+ break;
+ }
return 0;
}
+/* Returns non-zero if X might set something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_set_p (x)
+ rtx x;
+{
+
+ if (INSN_P (x))
+ {
+ if (GET_CODE (x) == CALL_INSN)
+ {
+ if (! CONST_OR_PURE_CALL_P (x))
+ return 1;
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
+ }
+
+ return for_each_rtx (&x, nonlocal_set_p_1, NULL);
+}
+
/* Mark the function if it is constant. */
void
mark_constant_function ()
{
rtx insn;
+ int nonlocal_memory_referenced;
if (TREE_PUBLIC (current_function_decl)
|| TREE_READONLY (current_function_decl)
+ || DECL_IS_PURE (current_function_decl)
|| TREE_THIS_VOLATILE (current_function_decl)
- || TYPE_MODE (TREE_TYPE (current_function_decl)) == VOIDmode)
+ || TYPE_MODE (TREE_TYPE (current_function_decl)) == VOIDmode
+ || current_function_has_nonlocal_goto)
+ return;
+
+ /* A loop might not return which counts as a side effect. */
+ if (mark_dfs_back_edges ())
return;
- /* Determine if this is a constant function. */
+ nonlocal_memory_referenced = 0;
+
+ init_alias_analysis ();
+
+ /* Determine if this is a constant or pure function. */
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i'
- && nonlocal_reference_p (insn))
- return;
+ {
+ if (! INSN_P (insn))
+ continue;
- /* Mark the function. */
+ if (nonlocal_set_p (insn) || global_reg_mentioned_p (insn)
+ || volatile_refs_p (PATTERN (insn)))
+ break;
- TREE_READONLY (current_function_decl) = 1;
+ if (! nonlocal_memory_referenced)
+ nonlocal_memory_referenced = nonlocal_referenced_p (insn);
+ }
+
+ end_alias_analysis ();
+
+ /* Mark the function. */
+
+ if (insn)
+ ;
+ else if (nonlocal_memory_referenced)
+ DECL_IS_PURE (current_function_decl) = 1;
+ else
+ TREE_READONLY (current_function_decl) = 1;
}
-
+\f
static HARD_REG_SET argument_registers;
void
init_alias_once ()
{
- register int i;
+ int i;
#ifndef OUTGOING_REGNO
#define OUTGOING_REGNO(N) N
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
/* Check whether this register can hold an incoming pointer
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))
&& HARD_REGNO_MODE_OK (i, Pmode))
SET_HARD_REG_BIT (argument_registers, i);
alias_sets = splay_tree_new (splay_tree_compare_ints, 0, 0);
}
+/* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE
+ array. */
+
void
init_alias_analysis ()
{
int maxreg = max_reg_num ();
int changed, pass;
- register int i;
- register unsigned int ui;
- register rtx insn;
+ int i;
+ unsigned int ui;
+ rtx insn;
reg_known_value_size = maxreg;
registers. */
reg_base_value_size = maxreg * 2;
reg_base_value = (rtx *) xcalloc (reg_base_value_size, sizeof (rtx));
- if (ggc_p)
- ggc_add_rtx_root (reg_base_value, reg_base_value_size);
+ ggc_add_rtx_root (reg_base_value, reg_base_value_size);
new_reg_base_value = (rtx *) xmalloc (reg_base_value_size * sizeof (rtx));
reg_seen = (char *) xmalloc (reg_base_value_size);
/* ??? Why are we realloc'ing if we're just going to zero it? */
alias_invariant = (rtx *)xrealloc (alias_invariant,
reg_base_value_size * sizeof (rtx));
- bzero ((char *)alias_invariant, reg_base_value_size * sizeof (rtx));
+ memset ((char *)alias_invariant, 0, reg_base_value_size * sizeof (rtx));
}
-
/* The basic idea is that each pass through this loop will use the
"constant" information from the previous pass to propagate alias
start counting from zero each iteration of the loop. */
unique_id = 0;
- /* We're at the start of the funtion each iteration through the
+ /* We're at the start of the function each iteration through the
loop, so we're copying arguments. */
copying_arguments = 1;
/* Wipe the potential alias information clean for this pass. */
- bzero ((char *) new_reg_base_value, reg_base_value_size * sizeof (rtx));
+ memset ((char *) new_reg_base_value, 0, reg_base_value_size * sizeof (rtx));
/* Wipe the reg_seen array clean. */
- bzero ((char *) reg_seen, reg_base_value_size);
+ memset ((char *) reg_seen, 0, reg_base_value_size);
/* Mark all hard registers which may contain an address.
The stack, frame and argument pointers may contain an address.
new_reg_base_value[HARD_FRAME_POINTER_REGNUM]
= gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
#endif
- if (struct_value_incoming_rtx
- && GET_CODE (struct_value_incoming_rtx) == REG)
- new_reg_base_value[REGNO (struct_value_incoming_rtx)]
- = gen_rtx_ADDRESS (Pmode, struct_value_incoming_rtx);
-
- if (static_chain_rtx
- && GET_CODE (static_chain_rtx) == REG)
- new_reg_base_value[REGNO (static_chain_rtx)]
- = gen_rtx_ADDRESS (Pmode, static_chain_rtx);
/* Walk the insns adding values to the new_reg_base_value array. */
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
{
-#if defined (HAVE_prologue) || defined (HAVE_epilogue)
- if (prologue_epilogue_contains (insn))
- continue;
-#endif
- if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
+ if (INSN_P (insn))
{
rtx note, set;
+
+#if defined (HAVE_prologue) || defined (HAVE_epilogue)
+ /* The prologue/epilogue insns are not threaded onto the
+ insn chain until after reload has completed. Thus,
+ there is no sense wasting time checking if INSN is in
+ the prologue/epilogue until after reload has completed. */
+ if (reload_completed
+ && prologue_epilogue_contains (insn))
+ continue;
+#endif
+
/* If this insn has a noalias note, process it, Otherwise,
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
- && (find_reg_note (insn, REG_NOALIAS, NULL_RTX)))
+ && REG_NOTES (insn) != 0
+ && find_reg_note (insn, REG_NOALIAS, NULL_RTX))
record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL);
else
note_stores (PATTERN (insn), record_set, NULL);
if (set != 0
&& GET_CODE (SET_DEST (set)) == REG
- && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER
- && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
- && REG_N_SETS (REGNO (SET_DEST (set))) == 1)
- || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
- && GET_CODE (XEXP (note, 0)) != EXPR_LIST
- && ! reg_overlap_mentioned_p (SET_DEST (set), XEXP (note, 0)))
+ && REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER)
{
- int regno = REGNO (SET_DEST (set));
- reg_known_value[regno] = XEXP (note, 0);
- reg_known_equiv_p[regno] = REG_NOTE_KIND (note) == REG_EQUIV;
+ unsigned int regno = REGNO (SET_DEST (set));
+ rtx src = SET_SRC (set);
+
+ if (REG_NOTES (insn) != 0
+ && (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
+ && REG_N_SETS (regno) == 1)
+ || (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
+ && GET_CODE (XEXP (note, 0)) != EXPR_LIST
+ && ! rtx_varies_p (XEXP (note, 0), 1)
+ && ! reg_overlap_mentioned_p (SET_DEST (set), XEXP (note, 0)))
+ {
+ reg_known_value[regno] = XEXP (note, 0);
+ reg_known_equiv_p[regno] = REG_NOTE_KIND (note) == REG_EQUIV;
+ }
+ else if (REG_N_SETS (regno) == 1
+ && GET_CODE (src) == PLUS
+ && GET_CODE (XEXP (src, 0)) == REG
+ && REGNO (XEXP (src, 0)) >= FIRST_PSEUDO_REGISTER
+ && (reg_known_value[REGNO (XEXP (src, 0))])
+ && GET_CODE (XEXP (src, 1)) == CONST_INT)
+ {
+ rtx op0 = XEXP (src, 0);
+ op0 = reg_known_value[REGNO (op0)];
+ reg_known_value[regno]
+ = plus_constant (op0, INTVAL (XEXP (src, 1)));
+ reg_known_equiv_p[regno] = 0;
+ }
+ else if (REG_N_SETS (regno) == 1
+ && ! rtx_varies_p (src, 1))
+ {
+ reg_known_value[regno] = src;
+ reg_known_equiv_p[regno] = 0;
+ }
}
}
else if (GET_CODE (insn) == NOTE
reg_known_equiv_p = 0;
if (reg_base_value)
{
- if (ggc_p)
- ggc_del_root (reg_base_value);
+ ggc_del_root (reg_base_value);
free (reg_base_value);
reg_base_value = 0;
}
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