/* Alias analysis for GNU C
- Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
+ Free Software Foundation, Inc.
Contributed by John Carr (jfc@mit.edu).
This file is part of GCC.
#include "config.h"
#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "tm_p.h"
#include "cselib.h"
#include "splay-tree.h"
#include "ggc.h"
+#include "langhooks.h"
+#include "timevar.h"
+#include "target.h"
+#include "cgraph.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
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
+ past immediate descendants, however, since we propagate all
grandchildren up one level.
Alias set zero is implicitly a superset of all other alias sets.
HOST_WIDE_INT alias_set;
/* The children of the alias set. These are not just the immediate
- children, but, in fact, all descendents. So, if we have:
+ children, but, in fact, all descendants. So, if we have:
- struct T { struct S s; float f; }
+ struct T { struct S s; float f; }
continuing our example above, the children here will be all of
`int', `double', `float', and `struct S'. */
int has_zero_child;
} *alias_set_entry;
-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_term PARAMS ((rtx));
-static int base_alias_check PARAMS ((rtx, rtx, enum machine_mode,
- enum machine_mode));
-static int handled_component_p PARAMS ((tree));
-static int can_address_p PARAMS ((tree));
-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 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 int write_dependence_p PARAMS ((rtx, rtx, int));
-static int nonlocal_mentioned_p PARAMS ((rtx));
+static int rtx_equal_for_memref_p (rtx, rtx);
+static rtx find_symbolic_term (rtx);
+static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT);
+static void record_set (rtx, rtx, void *);
+static int base_alias_check (rtx, rtx, enum machine_mode,
+ enum machine_mode);
+static rtx find_base_value (rtx);
+static int mems_in_disjoint_alias_sets_p (rtx, rtx);
+static int insert_subset_children (splay_tree_node, void*);
+static tree find_base_decl (tree);
+static alias_set_entry get_alias_set_entry (HOST_WIDE_INT);
+static rtx fixed_scalar_and_varying_struct_p (rtx, rtx, rtx, rtx,
+ int (*) (rtx, int));
+static int aliases_everything_p (rtx);
+static bool nonoverlapping_component_refs_p (tree, tree);
+static tree decl_for_component_ref (tree);
+static rtx adjust_offset_for_component_ref (tree, rtx);
+static int nonoverlapping_memrefs_p (rtx, rtx);
+static int write_dependence_p (rtx, rtx, int);
+
+static int nonlocal_mentioned_p_1 (rtx *, void *);
+static int nonlocal_mentioned_p (rtx);
+static int nonlocal_referenced_p_1 (rtx *, void *);
+static int nonlocal_referenced_p (rtx);
+static int nonlocal_set_p_1 (rtx *, void *);
+static int nonlocal_set_p (rtx);
+static void memory_modified_1 (rtx, rtx, void *);
/* Set up all info needed to perform alias analysis on memory references. */
/* Cap the number of passes we make over the insns propagating alias
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.
If all sets after the first add or subtract to the current value
or otherwise modify it so it does not point to a different top level
A base address can be an ADDRESS, SYMBOL_REF, or LABEL_REF. ADDRESS
expressions represent certain special values: function arguments and
- the stack, frame, and argument pointers.
+ the stack, frame, and argument pointers.
The contents of an ADDRESS is not normally used, the mode of the
ADDRESS determines whether the ADDRESS is a function argument or some
current function performs nonlocal memory memory references for the
purposes of marking the function as a constant function. */
-static rtx *reg_base_value;
+static GTY((length ("reg_base_value_size"))) rtx *reg_base_value;
static rtx *new_reg_base_value;
static unsigned int reg_base_value_size; /* size of reg_base_value array */
+/* Static hunks of RTL used by the aliasing code; these are initialized
+ once per function to avoid unnecessary RTL allocations. */
+static GTY (()) rtx static_reg_base_value[FIRST_PSEUDO_REGISTER];
+
#define REG_BASE_VALUE(X) \
(REGNO (X) < reg_base_value_size \
? reg_base_value[REGNO (X)] : 0)
/* True when scanning insns from the start of the rtl to the
NOTE_INSN_FUNCTION_BEG note. */
-static int copying_arguments;
+static bool copying_arguments;
/* The splay-tree used to store the various alias set entries. */
static splay_tree alias_sets;
such an entry, or NULL otherwise. */
static alias_set_entry
-get_alias_set_entry (alias_set)
- HOST_WIDE_INT alias_set;
+get_alias_set_entry (HOST_WIDE_INT alias_set)
{
splay_tree_node sn
= splay_tree_lookup (alias_sets, (splay_tree_key) alias_set);
/* 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;
+static int
+mems_in_disjoint_alias_sets_p (rtx mem1, rtx mem2)
{
-#ifdef ENABLE_CHECKING
+#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
whereby someone uses PUT_CODE, but doesn't clear MEM_ALIAS_SET, or
record_alias_subset via splay_tree_foreach. */
static int
-insert_subset_children (node, data)
- 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);
/* Return 1 if the two specified alias sets may conflict. */
int
-alias_sets_conflict_p (set1, set2)
- HOST_WIDE_INT set1, set2;
+alias_sets_conflict_p (HOST_WIDE_INT set1, HOST_WIDE_INT set2)
{
alias_set_entry ase;
return 0;
}
\f
-/* Set the alias set of MEM to SET. */
-
-void
-set_mem_alias_set (mem, set)
- rtx mem;
- HOST_WIDE_INT set;
-{
- /* We would like to do this test but can't yet since when converting a
- REG to a MEM, the alias set field is undefined. */
-#if 0
- /* If the new and old alias sets don't conflict, something is wrong. */
- if (!alias_sets_conflict_p (set, MEM_ALIAS_SET (mem)))
- abort ();
-#endif
-
- MEM_ALIAS_SET (mem) = set;
-}
-\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;
+readonly_fields_p (tree type)
{
tree field;
NULL_TREE, it means we know nothing about the storage. */
int
-objects_must_conflict_p (t1, t2)
- tree t1, t2;
+objects_must_conflict_p (tree t1, tree 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
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)))
+ || (t1 != 0 && lang_hooks.honor_readonly && TYPE_READONLY (t1))
+ || (t2 != 0 && lang_hooks.honor_readonly && TYPE_READONLY (t2)))
return 0;
/* If they are the same type, they must conflict. */
/* 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 retured. */
+ NULL_TREE is returned. */
static tree
-find_base_decl (t)
- tree t;
+find_base_decl (tree t)
{
tree d0, d1, d2;
}
}
-/* Return 1 if T is an expression that get_inner_reference handles. */
-
-static int
-handled_component_p (t)
- tree t;
-{
- switch (TREE_CODE (t))
- {
- case BIT_FIELD_REF:
- case COMPONENT_REF:
- case ARRAY_REF:
- case ARRAY_RANGE_REF:
- case NON_LVALUE_EXPR:
- return 1;
-
- case NOP_EXPR:
- case CONVERT_EXPR:
- return (TYPE_MODE (TREE_TYPE (t))
- == TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 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. */
-static int
-can_address_p (t)
- tree t;
+int
+can_address_p (tree t)
{
/* If we're at the end, it is vacuously addressable. */
if (! handled_component_p (t))
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;
expression. Call language-specific routine for help, if needed. */
HOST_WIDE_INT
-get_alias_set (t)
- tree t;
+get_alias_set (tree t)
{
- tree orig_t;
HOST_WIDE_INT set;
/* If we're not doing any alias analysis, just assume everything
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 and start by removing nops
- since we care only about the actual object. */
+ 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))
{
- while (TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR
- || TREE_CODE (t) == NON_LVALUE_EXPR)
- t = TREE_OPERAND (t, 0);
-
- /* Now give the language a chance to do something but record what we
- gave it this time. */
- orig_t = t;
- if ((set = lang_get_alias_set (t)) != -1)
+ 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;
- /* Now loop the same way as get_inner_reference and get the alias
- set to use. Pick up the outermost object that we could have
- a pointer to. */
- while (handled_component_p (t) && ! can_address_p (t))
- t = TREE_OPERAND (t, 0);
+ /* 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);
+ }
- if (TREE_CODE (t) == INDIRECT_REF)
+ /* Check for accesses through restrict-qualified pointers. */
+ if (TREE_CODE (inner) == INDIRECT_REF)
{
- /* Check for accesses through restrict-qualified pointers. */
- tree decl = find_base_decl (TREE_OPERAND (t, 0));
+ tree decl = find_base_decl (TREE_OPERAND (inner, 0));
if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
- /* We use the alias set indicated in the declaration. */
- return DECL_POINTER_ALIAS_SET (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. */
- if (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE)
+ else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE)
return 0;
}
- /* If we've already determined the alias set for this decl, just
- return it. This is necessary for C++ anonymous unions, whose
- component variables don't look like union members (boo!). */
+ /* 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));
- /* Give the language another chance to do something special. */
- if (orig_t != t
- && (set = lang_get_alias_set (t)) != -1)
- return set;
-
/* 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_P (t) && TYPE_ALIAS_SET_KNOWN_P (t))
+ if (TYPE_ALIAS_SET_KNOWN_P (t))
return TYPE_ALIAS_SET (t);
/* See if the language has special handling for this type. */
- if ((set = lang_get_alias_set (t)) != -1)
- {
- /* If the alias set is now known, we are done. */
- if (TYPE_ALIAS_SET_KNOWN_P (t))
- return TYPE_ALIAS_SET (t);
- }
+ 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;
+
+ /* Unless the language specifies otherwise, let vector types alias
+ their components. This avoids some nasty type punning issues in
+ normal usage. And indeed lets vectors be treated more like an
+ array slice. */
+ else if (TREE_CODE (t) == VECTOR_TYPE)
+ set = get_alias_set (TREE_TYPE (t));
+
else
/* Otherwise make a new alias set for this type. */
set = new_alias_set ();
/* Return a brand-new alias set. */
HOST_WIDE_INT
-new_alias_set ()
+new_alias_set (void)
{
static HOST_WIDE_INT last_alias_set;
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.
+ 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)
- 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 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 = 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
attach the SUBSET. */
superset_entry
= (alias_set_entry) xmalloc (sizeof (struct alias_set_entry));
superset_entry->alias_set = superset;
- superset_entry->children
+ 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,
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)
{
if (subset_entry->has_zero_child)
superset_entry->has_zero_child = 1;
}
/* 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);
}
}
function if the individual component aren't addressable. */
void
-record_component_aliases (type)
- tree type;
+record_component_aliases (tree type)
{
HOST_WIDE_INT superset = get_alias_set (type);
tree field;
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)));
spill area. */
HOST_WIDE_INT
-get_varargs_alias_set ()
+get_varargs_alias_set (void)
{
static HOST_WIDE_INT set = -1;
save areas. */
HOST_WIDE_INT
-get_frame_alias_set ()
+get_frame_alias_set (void)
{
static HOST_WIDE_INT set = -1;
/* Inside SRC, the source of a SET, find a base address. */
static rtx
-find_base_value (src)
- register rtx src;
+find_base_value (rtx src)
{
unsigned int regno;
+
switch (GET_CODE (src))
{
case SYMBOL_REF:
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 >= FIRST_PSEUDO_REGISTER
- && regno < reg_base_value_size
- && reg_base_value[regno])
- return reg_base_value[regno];
+ if ((regno >= FIRST_PSEUDO_REGISTER || fixed_regs[regno])
+ && regno < reg_base_value_size)
+ {
+ /* If we're inside init_alias_analysis, use new_reg_base_value
+ to reduce the number of relaxation iterations. */
+ if (new_reg_base_value && new_reg_base_value[regno]
+ && REG_N_SETS (regno) == 1)
+ return new_reg_base_value[regno];
+
+ if (reg_base_value[regno])
+ return reg_base_value[regno];
+ }
return src;
{
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 && REG_POINTER (src_0))
- return find_base_value (src_0);
- else if (GET_CODE (src_1) == REG && REG_POINTER (src_1))
- return find_base_value (src_1);
-
return 0;
}
if (GET_MODE_SIZE (GET_MODE (src)) < GET_MODE_SIZE (Pmode))
break;
/* Fall through. */
- case ZERO_EXTEND:
- case SIGN_EXTEND: /* used for NT/Alpha pointers */
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;
}
static int unique_id;
static void
-record_set (dest, set, data)
- rtx dest, set;
- void *data ATTRIBUTE_UNUSED;
+record_set (rtx dest, rtx set, void *data ATTRIBUTE_UNUSED)
{
- register unsigned regno;
+ unsigned regno;
rtx src;
+ int n;
if (GET_CODE (dest) != REG)
return;
if (regno >= reg_base_value_size)
abort ();
+ /* If this spans multiple hard registers, then we must indicate that every
+ register has an unusable value. */
+ if (regno < FIRST_PSEUDO_REGISTER)
+ n = HARD_REGNO_NREGS (regno, GET_MODE (dest));
+ else
+ n = 1;
+ if (n != 1)
+ {
+ while (--n >= 0)
+ {
+ reg_seen[regno + n] = 1;
+ new_reg_base_value[regno + n] = 0;
+ }
+ return;
+ }
+
if (set)
{
/* A CLOBBER wipes out any old value but does not prevent a previously
are different. */
void
-record_base_value (regno, val, invariant)
- unsigned int regno;
- rtx val;
- int invariant;
+record_base_value (unsigned int regno, rtx val, int invariant)
{
if (regno >= reg_base_value_size)
return;
changes the offset. */
void
-clear_reg_alias_info (reg)
- rtx reg;
+clear_reg_alias_info (rtx reg)
{
unsigned int regno = REGNO (reg);
whose address is the SYMBOL_REF is returned.) */
rtx
-canon_rtx (x)
- rtx x;
+canon_rtx (rtx x)
{
/* Recursively look for equivalences. */
if (GET_CODE (x) == REG && REGNO (x) >= FIRST_PSEUDO_REGISTER
}
/* Return 1 if X and Y are identical-looking rtx's.
+ Expect that X and Y has been already canonicalized.
We use the data in reg_known_value above to see if two registers with
different numbers are, in fact, equivalent. */
static int
-rtx_equal_for_memref_p (x, y)
- rtx x, y;
+rtx_equal_for_memref_p (rtx x, rtx 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 (x == 0 || y == 0)
return 0;
- x = canon_rtx (x);
- y = canon_rtx (y);
-
if (x == y)
return 1;
case LABEL_REF:
return XEXP (x, 0) == XEXP (y, 0);
-
+
case SYMBOL_REF:
return XSTR (x, 0) == XSTR (y, 0);
case ADDRESSOF:
return (XINT (x, 1) == XINT (y, 1)
- && rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0)));
+ && 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. */
- if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c')
+ /* canon_rtx knows how to handle plus. No need to canonicalize. */
+ if (code == PLUS)
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, 0), XEXP (y, 1))
&& rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 0))));
+ /* For commutative operations, the RTX match if the operand match in any
+ order. Also handle the simple binary and unary cases without a loop. */
+ if (code == EQ || code == NE || GET_RTX_CLASS (code) == 'c')
+ {
+ rtx xop0 = canon_rtx (XEXP (x, 0));
+ rtx yop0 = canon_rtx (XEXP (y, 0));
+ rtx yop1 = canon_rtx (XEXP (y, 1));
+
+ return ((rtx_equal_for_memref_p (xop0, yop0)
+ && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop1))
+ || (rtx_equal_for_memref_p (xop0, yop1)
+ && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)), yop0)));
+ }
else if (GET_RTX_CLASS (code) == '<' || GET_RTX_CLASS (code) == '2')
- return (rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0))
- && rtx_equal_for_memref_p (XEXP (x, 1), XEXP (y, 1)));
+ {
+ return (rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)),
+ canon_rtx (XEXP (y, 0)))
+ && rtx_equal_for_memref_p (canon_rtx (XEXP (x, 1)),
+ canon_rtx (XEXP (y, 1))));
+ }
else if (GET_RTX_CLASS (code) == '1')
- return rtx_equal_for_memref_p (XEXP (x, 0), XEXP (y, 0));
+ return rtx_equal_for_memref_p (canon_rtx (XEXP (x, 0)),
+ canon_rtx (XEXP (y, 0)));
/* Compare the elements. If any pair of corresponding elements
fail to match, return 0 for the whole things.
/* And the corresponding elements must match. */
for (j = 0; j < XVECLEN (x, i); j++)
- if (rtx_equal_for_memref_p (XVECEXP (x, i, j),
- XVECEXP (y, i, j)) == 0)
+ if (rtx_equal_for_memref_p (canon_rtx (XVECEXP (x, i, j)),
+ canon_rtx (XVECEXP (y, i, j))) == 0)
return 0;
break;
case 'e':
- if (rtx_equal_for_memref_p (XEXP (x, i), XEXP (y, i)) == 0)
+ if (rtx_equal_for_memref_p (canon_rtx (XEXP (x, i)),
+ canon_rtx (XEXP (y, i))) == 0)
return 0;
break;
X and return it, or return 0 if none found. */
static rtx
-find_symbolic_term (x)
- rtx x;
+find_symbolic_term (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)
return 0;
}
-static rtx
-find_base_term (x)
- register rtx x;
+rtx
+find_base_term (rtx x)
{
cselib_val *val;
struct elt_loc_list *l;
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)
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.
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
other operand is the base register. */
-
+
if (tmp1 == pic_offset_table_rtx && CONSTANT_P (tmp2))
return find_base_term (tmp2);
}
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:
objects, 1 if they might be pointers to the same object. */
static int
-base_alias_check (x, y, x_mode, y_mode)
- rtx x, y;
- enum machine_mode x_mode, y_mode;
+base_alias_check (rtx x, rtx y, enum machine_mode x_mode,
+ enum machine_mode y_mode)
{
rtx x_base = find_base_term (x);
rtx y_base = find_base_term (y);
if (rtx_equal_p (x_base, y_base))
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
no conflict. We can bring knowledge of object alignment into play
here. For example, on alpha, "char a, b;" can alias one another,
a more useful rtx. */
rtx
-get_addr (x)
- rtx x;
+get_addr (rtx x)
{
cselib_val *v;
struct elt_loc_list *l;
is not modified by the memory reference then ADDR is returned. */
rtx
-addr_side_effect_eval (addr, size, n_refs)
- rtx addr;
- int size;
- int n_refs;
+addr_side_effect_eval (rtx addr, int size, int n_refs)
{
int offset = 0;
-
+
switch (GET_CODE (addr))
{
case PRE_INC:
default:
return addr;
}
-
+
if (offset)
- addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0), GEN_INT (offset));
+ addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0),
+ GEN_INT (offset));
else
addr = XEXP (addr, 0);
+ addr = canon_rtx (addr);
return addr;
}
C is nonzero, we are testing aliases between X and Y + C.
XSIZE is the size in bytes of the X reference,
similarly YSIZE is the size in bytes for 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
referenced (the reference was BLKmode), so make the most pessimistic
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;
- int xsize, ysize;
- HOST_WIDE_INT c;
+memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
{
if (GET_CODE (x) == VALUE)
x = get_addr (x);
else if (GET_CODE (x) == LO_SUM)
x = XEXP (x, 1);
else
- x = canon_rtx (addr_side_effect_eval (x, xsize, 0));
+ x = addr_side_effect_eval (x, xsize, 0);
if (GET_CODE (y) == HIGH)
y = XEXP (y, 0);
else if (GET_CODE (y) == LO_SUM)
y = XEXP (y, 1);
else
- y = canon_rtx (addr_side_effect_eval (y, ysize, 0));
+ y = addr_side_effect_eval (y, ysize, 0);
if (rtx_equal_for_memref_p (x, y))
{
}
/* 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
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 (y) == AND || ysize < -INTVAL (XEXP (x, 1)))
xsize = -1;
- return memrefs_conflict_p (xsize, 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 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
a following reference, so we do nothing with that for now. */
if (GET_CODE (x) == AND || xsize < -INTVAL (XEXP (y, 1)))
ysize = -1;
- return memrefs_conflict_p (xsize, x, ysize, XEXP (y, 0), c);
+ return memrefs_conflict_p (xsize, x, ysize, canon_rtx (XEXP (y, 0)), c);
}
if (GET_CODE (x) == ADDRESSOF)
If both memory references are volatile, then there must always be a
dependence between the two references, since their order can not be
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
conflict with a non-MEM_IN_STRUCT reference at a fixed address. We
only be a dependence here if both reads are volatile. */
int
-read_dependence (mem, x)
- rtx mem;
- rtx x;
+read_dependence (rtx mem, rtx x)
{
return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem);
}
to decide whether or not an address may vary; it should return
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));
-{
+fixed_scalar_and_varying_struct_p (rtx mem1, rtx mem2, rtx mem1_addr,
+ rtx mem2_addr,
+ int (*varies_p) (rtx, int))
+{
if (! flag_strict_aliasing)
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))
/* 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)
+ if (MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2)
&& 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. */
indicates that it might well alias *anything*. */
static int
-aliases_everything_p (mem)
- rtx mem;
+aliases_everything_p (rtx mem)
{
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 1;
-
+
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 (tree x, tree 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 (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 (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 determine the exprs corresponding to memrefs
+ X and Y and they do not overlap. */
+
+static int
+nonoverlapping_memrefs_p (rtx x, rtx 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;
+ }
+ else if (TREE_CODE (exprx) == INDIRECT_REF)
+ {
+ exprx = TREE_OPERAND (exprx, 0);
+ if (flag_argument_noalias < 2
+ || TREE_CODE (exprx) != PARM_DECL)
+ return 0;
+ }
+
+ 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;
+ }
+ else if (TREE_CODE (expry) == INDIRECT_REF)
+ {
+ expry = TREE_OPERAND (expry, 0);
+ if (flag_argument_noalias < 2
+ || TREE_CODE (expry) != PARM_DECL)
+ return 0;
+ }
+
+ 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
-true_dependence (mem, mem_mode, x, varies)
- rtx mem;
- enum machine_mode mem_mode;
- rtx x;
- int (*varies) PARAMS ((rtx, int));
+true_dependence (rtx mem, enum machine_mode mem_mode, rtx x,
+ int (*varies) (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;
+ /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
+ This is used in epilogue deallocation functions. */
+ if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
+ return 1;
+ if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
+ return 1;
+
if (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
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);
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;
}
/* Canonical true dependence: X is read after store in MEM takes place.
- Variant of true_dependece 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
+ 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));
+canon_true_dependence (rtx mem, enum machine_mode mem_mode, rtx mem_addr,
+ rtx x, int (*varies) (rtx, int))
{
- register rtx x_addr;
+ rtx x_addr;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
+ /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
+ This is used in epilogue deallocation functions. */
+ if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
+ return 1;
+ if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
+ return 1;
+
if (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
if (RTX_UNCHANGING_P (x) && ! RTX_UNCHANGING_P (mem))
return 0;
+ if (nonoverlapping_memrefs_p (x, mem))
+ return 0;
+
x_addr = get_addr (XEXP (x, 0));
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
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;
varies);
}
-/* Returns non-zero if a write to X might alias a previous read from
- (or, if WRITEP is non-zero, a write to) MEM. */
+/* Returns nonzero if a write to X might alias a previous read from
+ (or, if WRITEP is nonzero, a write to) MEM. */
static int
-write_dependence_p (mem, x, writep)
- rtx mem;
- rtx x;
- int writep;
+write_dependence_p (rtx mem, rtx x, int writep)
{
rtx x_addr, mem_addr;
rtx fixed_scalar;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
+ /* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
+ This is used in epilogue deallocation functions. */
+ if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
+ return 1;
+ if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
+ return 1;
+
if (DIFFERENT_ALIAS_SETS_P (x, mem))
return 0;
if (! writep && RTX_UNCHANGING_P (mem))
return 0;
+ if (nonoverlapping_memrefs_p (x, mem))
+ return 0;
+
x_addr = get_addr (XEXP (x, 0));
mem_addr = get_addr (XEXP (mem, 0));
SIZE_FOR_MODE (x), x_addr, 0))
return 0;
- fixed_scalar
+ fixed_scalar
= fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
rtx_addr_varies_p);
/* Anti dependence: X is written after read in MEM takes place. */
int
-anti_dependence (mem, x)
- rtx mem;
- rtx x;
+anti_dependence (rtx mem, rtx x)
{
return write_dependence_p (mem, x, /*writep=*/0);
}
/* Output dependence: X is written after store in MEM takes place. */
int
-output_dependence (mem, x)
- register rtx mem;
- register rtx x;
+output_dependence (rtx mem, rtx x)
{
return write_dependence_p (mem, x, /*writep=*/1);
}
-
-/* Returns non-zero if X mentions 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_mentioned_p (x)
- rtx x;
+nonlocal_mentioned_p_1 (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 can be constant if they don't use
- scratch memory used to mark function w/o side effects. */
- if (code == CALL_INSN && CONST_OR_PURE_CALL_P (x))
- {
- x = CALL_INSN_FUNCTION_USAGE (x);
- if (x == 0)
- return 0;
- }
- else
- 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)
case CC0:
case CONST_INT:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case CONST:
case LABEL_REF:
return 0;
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' && XEXP (x, i))
- {
- if (nonlocal_mentioned_p (XEXP (x, i)))
- return 1;
- }
- else if (fmt[i] == 'E')
- {
- register int j;
- for (j = 0; j < XVECLEN (x, i); j++)
- if (nonlocal_mentioned_p (XVECEXP (x, i, j)))
- return 1;
- }
- }
- }
+/* Returns nonzero if X might mention something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_mentioned_p (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 (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;
+ }
return 0;
}
-/* Mark the function if it is constant. */
+/* Returns nonzero if X might reference something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_referenced_p (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 (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 nonzero if X might set something which is not
+ local to the function and is not constant. */
+
+static int
+nonlocal_set_p (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 pure or constant. */
void
-mark_constant_function ()
+mark_constant_function (void)
{
rtx insn;
- int nonlocal_mentioned;
+ int nonlocal_memory_referenced;
- if (TREE_PUBLIC (current_function_decl)
- || TREE_READONLY (current_function_decl)
+ if (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)
+ || current_function_has_nonlocal_goto
+ || !(*targetm.binds_local_p) (current_function_decl))
return;
/* A loop might not return which counts as a side effect. */
if (mark_dfs_back_edges ())
return;
- nonlocal_mentioned = 0;
+ nonlocal_memory_referenced = 0;
init_alias_analysis ();
- /* Determine if this is a constant function. */
+ /* Determine if this is a constant or pure function. */
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
- if (INSN_P (insn) && nonlocal_mentioned_p (insn))
- {
- nonlocal_mentioned = 1;
+ {
+ if (! INSN_P (insn))
+ continue;
+
+ if (nonlocal_set_p (insn) || global_reg_mentioned_p (insn)
+ || volatile_refs_p (PATTERN (insn)))
break;
- }
+
+ if (! nonlocal_memory_referenced)
+ nonlocal_memory_referenced = nonlocal_referenced_p (insn);
+ }
end_alias_analysis ();
/* Mark the function. */
- if (! nonlocal_mentioned)
- TREE_READONLY (current_function_decl) = 1;
+ if (insn)
+ ;
+ else if (nonlocal_memory_referenced)
+ {
+ cgraph_rtl_info (current_function_decl)->pure_function = 1;
+ DECL_IS_PURE (current_function_decl) = 1;
+ }
+ else
+ {
+ cgraph_rtl_info (current_function_decl)->const_function = 1;
+ TREE_READONLY (current_function_decl) = 1;
+ }
}
-
-
-static HARD_REG_SET argument_registers;
+\f
void
-init_alias_once ()
+init_alias_once (void)
{
- register int i;
+ int i;
#ifndef OUTGOING_REGNO
#define OUTGOING_REGNO(N) N
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);
+ static_reg_base_value[i]
+ = gen_rtx_ADDRESS (VOIDmode, gen_rtx_REG (Pmode, i));
+
+ static_reg_base_value[STACK_POINTER_REGNUM]
+ = gen_rtx_ADDRESS (Pmode, stack_pointer_rtx);
+ static_reg_base_value[ARG_POINTER_REGNUM]
+ = gen_rtx_ADDRESS (Pmode, arg_pointer_rtx);
+ static_reg_base_value[FRAME_POINTER_REGNUM]
+ = gen_rtx_ADDRESS (Pmode, frame_pointer_rtx);
+#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
+ static_reg_base_value[HARD_FRAME_POINTER_REGNUM]
+ = gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
+#endif
alias_sets = splay_tree_new (splay_tree_compare_ints, 0, 0);
}
+/* Set MEMORY_MODIFIED when X modifies DATA (that is assumed
+ to be memory reference. */
+static bool memory_modified;
+static void
+memory_modified_1 (rtx x, rtx pat ATTRIBUTE_UNUSED, void *data)
+{
+ if (GET_CODE (x) == MEM)
+ {
+ if (anti_dependence (x, (rtx)data) || output_dependence (x, (rtx)data))
+ memory_modified = true;
+ }
+}
+
+
+/* Return true when INSN possibly modify memory contents of MEM
+ (ie address can be modified). */
+bool
+memory_modified_in_insn_p (rtx mem, rtx insn)
+{
+ if (!INSN_P (insn))
+ return false;
+ memory_modified = false;
+ note_stores (PATTERN (insn), memory_modified_1, mem);
+ return memory_modified;
+}
+
/* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE
array. */
void
-init_alias_analysis ()
+init_alias_analysis (void)
{
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;
+
+ timevar_push (TV_ALIAS_ANALYSIS);
reg_known_value_size = maxreg;
- reg_known_value
+ reg_known_value
= (rtx *) xcalloc ((maxreg - FIRST_PSEUDO_REGISTER), sizeof (rtx))
- FIRST_PSEUDO_REGISTER;
- reg_known_equiv_p
+ reg_known_equiv_p
= (char*) xcalloc ((maxreg - FIRST_PSEUDO_REGISTER), sizeof (char))
- FIRST_PSEUDO_REGISTER;
optimization. Loop unrolling can create a large number of
registers. */
reg_base_value_size = maxreg * 2;
- reg_base_value = (rtx *) xcalloc (reg_base_value_size, sizeof (rtx));
- ggc_add_rtx_root (reg_base_value, reg_base_value_size);
+ reg_base_value = (rtx *) ggc_alloc_cleared (reg_base_value_size
+ * sizeof (rtx));
new_reg_base_value = (rtx *) xmalloc (reg_base_value_size * sizeof (rtx));
reg_seen = (char *) xmalloc (reg_base_value_size);
- if (! reload_completed && flag_unroll_loops)
+ if (! reload_completed && flag_old_unroll_loops)
{
/* ??? Why are we realloc'ing if we're just going to zero it? */
alias_invariant = (rtx *)xrealloc (alias_invariant,
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;
+ copying_arguments = true;
/* Wipe the potential alias information clean for this pass. */
memset ((char *) new_reg_base_value, 0, reg_base_value_size * sizeof (rtx));
The address expression is VOIDmode for an argument and
Pmode for other registers. */
- for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
- if (TEST_HARD_REG_BIT (argument_registers, i))
- new_reg_base_value[i] = gen_rtx_ADDRESS (VOIDmode,
- gen_rtx_REG (Pmode, i));
-
- new_reg_base_value[STACK_POINTER_REGNUM]
- = gen_rtx_ADDRESS (Pmode, stack_pointer_rtx);
- new_reg_base_value[ARG_POINTER_REGNUM]
- = gen_rtx_ADDRESS (Pmode, arg_pointer_rtx);
- new_reg_base_value[FRAME_POINTER_REGNUM]
- = gen_rtx_ADDRESS (Pmode, frame_pointer_rtx);
-#if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
- new_reg_base_value[HARD_FRAME_POINTER_REGNUM]
- = gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
-#endif
+ memcpy (new_reg_base_value, static_reg_base_value,
+ FIRST_PSEUDO_REGISTER * sizeof (rtx));
/* Walk the insns adding values to the new_reg_base_value array. */
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
rtx note, set;
#if defined (HAVE_prologue) || defined (HAVE_epilogue)
- /* The prologue/epilouge insns are not threaded onto the
+ /* 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. */
}
else if (GET_CODE (insn) == NOTE
&& NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
- copying_arguments = 0;
+ copying_arguments = false;
}
/* Now propagate values from new_reg_base_value to reg_base_value. */
new_reg_base_value = 0;
free (reg_seen);
reg_seen = 0;
+ timevar_pop (TV_ALIAS_ANALYSIS);
}
void
-end_alias_analysis ()
+end_alias_analysis (void)
{
free (reg_known_value + FIRST_PSEUDO_REGISTER);
reg_known_value = 0;
reg_known_value_size = 0;
free (reg_known_equiv_p + FIRST_PSEUDO_REGISTER);
reg_known_equiv_p = 0;
- if (reg_base_value)
- {
- ggc_del_root (reg_base_value);
- free (reg_base_value);
- reg_base_value = 0;
- }
+ reg_base_value = 0;
reg_base_value_size = 0;
if (alias_invariant)
{
alias_invariant = 0;
}
}
+
+#include "gt-alias.h"
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