/* Alias analysis for GNU C
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
- 2007 Free Software Foundation, Inc.
+ 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
Contributed by John Carr (jfc@mit.edu).
This file is part of GCC.
#include "basic-block.h"
#include "flags.h"
#include "output.h"
-#include "toplev.h"
+#include "diagnostic-core.h"
#include "cselib.h"
#include "splay-tree.h"
#include "ggc.h"
#include "timevar.h"
#include "target.h"
#include "cgraph.h"
-#include "varray.h"
#include "tree-pass.h"
-#include "ipa-type-escape.h"
#include "df.h"
+#include "tree-ssa-alias.h"
+#include "pointer-set.h"
+#include "tree-flow.h"
/* The aliasing API provided here solves related but different problems:
However, this is no actual entry for alias set zero. It is an
error to attempt to explicitly construct a subset of zero. */
-struct alias_set_entry GTY(())
-{
+struct GTY(()) alias_set_entry_d {
/* The alias set number, as stored in MEM_ALIAS_SET. */
alias_set_type alias_set;
`int', `double', `float', and `struct S'. */
splay_tree GTY((param1_is (int), param2_is (int))) children;
};
-typedef struct alias_set_entry *alias_set_entry;
+typedef struct alias_set_entry_d *alias_set_entry;
static int rtx_equal_for_memref_p (const_rtx, const_rtx);
static int memrefs_conflict_p (int, rtx, int, rtx, HOST_WIDE_INT);
static rtx find_base_value (rtx);
static int mems_in_disjoint_alias_sets_p (const_rtx, const_rtx);
static int insert_subset_children (splay_tree_node, void*);
-static tree find_base_decl (tree);
static alias_set_entry get_alias_set_entry (alias_set_type);
-static const_rtx fixed_scalar_and_varying_struct_p (const_rtx, const_rtx, rtx, rtx,
- bool (*) (const_rtx, bool));
static int aliases_everything_p (const_rtx);
static bool nonoverlapping_component_refs_p (const_tree, const_tree);
static tree decl_for_component_ref (tree);
-static rtx adjust_offset_for_component_ref (tree, rtx);
static int write_dependence_p (const_rtx, const_rtx, int);
static void memory_modified_1 (rtx, const_rtx, void *);
array. */
static GTY((deletable)) VEC(rtx,gc) *old_reg_base_value;
-/* 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 static_reg_base_value \
+ (this_target_rtl->x_static_reg_base_value)
#define REG_BASE_VALUE(X) \
(REGNO (X) < VEC_length (rtx, reg_base_value) \
/* The splay-tree used to store the various alias set entries. */
static GTY (()) VEC(alias_set_entry,gc) *alias_sets;
\f
+/* Build a decomposed reference object for querying the alias-oracle
+ from the MEM rtx and store it in *REF.
+ Returns false if MEM is not suitable for the alias-oracle. */
+
+static bool
+ao_ref_from_mem (ao_ref *ref, const_rtx mem)
+{
+ tree expr = MEM_EXPR (mem);
+ tree base;
+
+ if (!expr)
+ return false;
+
+ ao_ref_init (ref, expr);
+
+ /* Get the base of the reference and see if we have to reject or
+ adjust it. */
+ base = ao_ref_base (ref);
+ if (base == NULL_TREE)
+ return false;
+
+ /* The tree oracle doesn't like to have these. */
+ if (TREE_CODE (base) == FUNCTION_DECL
+ || TREE_CODE (base) == LABEL_DECL)
+ return false;
+
+ /* If this is a pointer dereference of a non-SSA_NAME punt.
+ ??? We could replace it with a pointer to anything. */
+ if ((INDIRECT_REF_P (base)
+ || TREE_CODE (base) == MEM_REF)
+ && TREE_CODE (TREE_OPERAND (base, 0)) != SSA_NAME)
+ return false;
+ if (TREE_CODE (base) == TARGET_MEM_REF
+ && TMR_BASE (base)
+ && TREE_CODE (TMR_BASE (base)) != SSA_NAME)
+ return false;
+
+ /* If this is a reference based on a partitioned decl replace the
+ base with an INDIRECT_REF of the pointer representative we
+ created during stack slot partitioning. */
+ if (TREE_CODE (base) == VAR_DECL
+ && ! TREE_STATIC (base)
+ && cfun->gimple_df->decls_to_pointers != NULL)
+ {
+ void *namep;
+ namep = pointer_map_contains (cfun->gimple_df->decls_to_pointers, base);
+ if (namep)
+ ref->base = build_simple_mem_ref (*(tree *)namep);
+ }
+ else if (TREE_CODE (base) == TARGET_MEM_REF
+ && TREE_CODE (TMR_BASE (base)) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (TMR_BASE (base), 0)) == VAR_DECL
+ && ! TREE_STATIC (TREE_OPERAND (TMR_BASE (base), 0))
+ && cfun->gimple_df->decls_to_pointers != NULL)
+ {
+ void *namep;
+ namep = pointer_map_contains (cfun->gimple_df->decls_to_pointers,
+ TREE_OPERAND (TMR_BASE (base), 0));
+ if (namep)
+ ref->base = build_simple_mem_ref (*(tree *)namep);
+ }
+
+ ref->ref_alias_set = MEM_ALIAS_SET (mem);
+
+ /* If MEM_OFFSET or MEM_SIZE are unknown we have to punt.
+ Keep points-to related information though. */
+ if (!MEM_OFFSET_KNOWN_P (mem)
+ || !MEM_SIZE_KNOWN_P (mem))
+ {
+ ref->ref = NULL_TREE;
+ ref->offset = 0;
+ ref->size = -1;
+ ref->max_size = -1;
+ return true;
+ }
+
+ /* If the base decl is a parameter we can have negative MEM_OFFSET in
+ case of promoted subregs on bigendian targets. Trust the MEM_EXPR
+ here. */
+ if (MEM_OFFSET (mem) < 0
+ && (MEM_SIZE (mem) + MEM_OFFSET (mem)) * BITS_PER_UNIT == ref->size)
+ return true;
+
+ ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT;
+ ref->size = MEM_SIZE (mem) * BITS_PER_UNIT;
+
+ /* The MEM may extend into adjacent fields, so adjust max_size if
+ necessary. */
+ if (ref->max_size != -1
+ && ref->size > ref->max_size)
+ ref->max_size = ref->size;
+
+ /* If MEM_OFFSET and MEM_SIZE get us outside of the base object of
+ the MEM_EXPR punt. This happens for STRICT_ALIGNMENT targets a lot. */
+ if (MEM_EXPR (mem) != get_spill_slot_decl (false)
+ && (ref->offset < 0
+ || (DECL_P (ref->base)
+ && (!host_integerp (DECL_SIZE (ref->base), 1)
+ || (TREE_INT_CST_LOW (DECL_SIZE ((ref->base)))
+ < (unsigned HOST_WIDE_INT)(ref->offset + ref->size))))))
+ return false;
+
+ return true;
+}
+
+/* Query the alias-oracle on whether the two memory rtx X and MEM may
+ alias. If TBAA_P is set also apply TBAA. Returns true if the
+ two rtxen may alias, false otherwise. */
+
+static bool
+rtx_refs_may_alias_p (const_rtx x, const_rtx mem, bool tbaa_p)
+{
+ ao_ref ref1, ref2;
+
+ if (!ao_ref_from_mem (&ref1, x)
+ || !ao_ref_from_mem (&ref2, mem))
+ return true;
+
+ return refs_may_alias_p_1 (&ref1, &ref2,
+ tbaa_p
+ && MEM_ALIAS_SET (x) != 0
+ && MEM_ALIAS_SET (mem) != 0);
+}
+
/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
such an entry, or NULL otherwise. */
/* Otherwise, check if set1 is a subset of set2. */
ase = get_alias_set_entry (set2);
if (ase != 0
- && ((ase->has_zero_child && set1 == 0)
+ && (ase->has_zero_child
|| splay_tree_lookup (ase->children,
(splay_tree_key) set1)))
return true;
return 0;
}
-static int
-walk_mems_2 (rtx *x, rtx mem)
-{
- if (MEM_P (*x))
- {
- if (alias_sets_conflict_p (MEM_ALIAS_SET(*x), MEM_ALIAS_SET(mem)))
- return 1;
-
- return -1;
- }
- return 0;
-}
-
-static int
-walk_mems_1 (rtx *x, rtx *pat)
-{
- if (MEM_P (*x))
- {
- /* Visit all MEMs in *PAT and check indepedence. */
- if (for_each_rtx (pat, (rtx_function) walk_mems_2, *x))
- /* Indicate that dependence was determined and stop traversal. */
- return 1;
-
- return -1;
- }
- return 0;
-}
-
-/* Return 1 if two specified instructions have mem expr with conflict alias sets*/
-bool
-insn_alias_sets_conflict_p (rtx insn1, rtx insn2)
-{
- /* For each pair of MEMs in INSN1 and INSN2 check their independence. */
- return for_each_rtx (&PATTERN (insn1), (rtx_function) walk_mems_1,
- &PATTERN (insn2));
-}
-
/* Return 1 if the two specified alias sets will always conflict. */
int
return alias_sets_must_conflict_p (set1, set2);
}
\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 (tree t)
-{
- tree d0, d1;
-
- if (t == 0 || t == error_mark_node || ! POINTER_TYPE_P (TREE_TYPE (t)))
- return 0;
-
- /* If this is a declaration, return it. If T is based on a restrict
- qualified decl, return that decl. */
- if (DECL_P (t))
- {
- if (TREE_CODE (t) == VAR_DECL && DECL_BASED_ON_RESTRICT_P (t))
- t = DECL_GET_RESTRICT_BASE (t);
- 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 tcc_unary:
- return find_base_decl (TREE_OPERAND (t, 0));
-
- case tcc_binary:
- /* 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;
-
- default:
- return 0;
- }
-}
-
/* Return true if all nested component references handled by
get_inner_reference in T are such that we should use the alias set
provided by the object at the heart of T.
}
}
+/* Return the alias set for the memory pointed to by T, which may be
+ either a type or an expression. Return -1 if there is nothing
+ special about dereferencing T. */
+
+static alias_set_type
+get_deref_alias_set_1 (tree t)
+{
+ /* If we're not doing any alias analysis, just assume everything
+ aliases everything else. */
+ if (!flag_strict_aliasing)
+ return 0;
+
+ /* All we care about is the type. */
+ if (! TYPE_P (t))
+ t = TREE_TYPE (t);
+
+ /* If we have an INDIRECT_REF via a void pointer, we don't
+ know anything about what that might alias. Likewise if the
+ pointer is marked that way. */
+ if (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE
+ || TYPE_REF_CAN_ALIAS_ALL (t))
+ return 0;
+
+ return -1;
+}
+
+/* Return the alias set for the memory pointed to by T, which may be
+ either a type or an expression. */
+
+alias_set_type
+get_deref_alias_set (tree t)
+{
+ alias_set_type set = get_deref_alias_set_1 (t);
+
+ /* Fall back to the alias-set of the pointed-to type. */
+ if (set == -1)
+ {
+ if (! TYPE_P (t))
+ t = TREE_TYPE (t);
+ set = get_alias_set (TREE_TYPE (t));
+ }
+
+ return set;
+}
+
/* Return the alias set for T, which may be either a type or an
expression. Call language-specific routine for help, if needed. */
aren't types. */
if (! TYPE_P (t))
{
- tree inner = t;
+ tree inner;
- /* Remove any nops, then give the language a chance to do
- something with this tree before we look at it. */
+ /* 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 *". */
+ /* Get the base object of the reference. */
+ inner = t;
while (handled_component_p (inner))
{
+ /* If there is a VIEW_CONVERT_EXPR in the chain we cannot use
+ the type of any component references that wrap it to
+ determine the alias-set. */
+ if (TREE_CODE (inner) == VIEW_CONVERT_EXPR)
+ t = TREE_OPERAND (inner, 0);
inner = TREE_OPERAND (inner, 0);
- STRIP_NOPS (inner);
}
- /* Check for accesses through restrict-qualified pointers. */
+ /* Handle pointer dereferences here, they can override the
+ alias-set. */
if (INDIRECT_REF_P (inner))
{
- tree decl;
-
- if (TREE_CODE (TREE_OPERAND (inner, 0)) == SSA_NAME)
- decl = SSA_NAME_VAR (TREE_OPERAND (inner, 0));
- else
- 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)
- {
- tree pointed_to_type = TREE_TYPE (TREE_TYPE (decl));
-
- /* 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. */
- alias_set_type pointed_to_alias_set
- = get_alias_set (pointed_to_type);
-
- if (pointed_to_alias_set == 0)
- /* It's not legal to make a subset of alias set zero. */
- DECL_POINTER_ALIAS_SET (decl) = 0;
- else if (AGGREGATE_TYPE_P (pointed_to_type))
- /* For an aggregate, we must treat the restricted
- pointer the same as an ordinary pointer. If we
- were to make the type pointed to by the
- restricted pointer a subset of the pointed-to
- type, then we would believe that other subsets
- of the pointed-to type (such as fields of that
- type) do not conflict with the type pointed to
- by the restricted pointer. */
- DECL_POINTER_ALIAS_SET (decl)
- = pointed_to_alias_set;
- 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. Likewise if the
- pointer is marked that way. */
- else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE
- || (TYPE_REF_CAN_ALIAS_ALL
- (TREE_TYPE (TREE_OPERAND (inner, 0)))))
- return 0;
+ set = get_deref_alias_set_1 (TREE_OPERAND (inner, 0));
+ if (set != -1)
+ return set;
}
+ else if (TREE_CODE (inner) == TARGET_MEM_REF)
+ return get_deref_alias_set (TMR_OFFSET (inner));
+ else if (TREE_CODE (inner) == MEM_REF)
+ {
+ set = get_deref_alias_set_1 (TREE_OPERAND (inner, 1));
+ if (set != -1)
+ return set;
+ }
+
+ /* If the innermost reference is a MEM_REF that has a
+ conversion embedded treat it like a VIEW_CONVERT_EXPR above,
+ using the memory access type for determining the alias-set. */
+ if (TREE_CODE (inner) == MEM_REF
+ && TYPE_MAIN_VARIANT (TREE_TYPE (inner))
+ != TYPE_MAIN_VARIANT
+ (TREE_TYPE (TREE_TYPE (TREE_OPERAND (inner, 1)))))
+ return get_deref_alias_set (TREE_OPERAND (inner, 1));
/* Otherwise, pick up the outermost object that we could have a pointer
to, processing conversions as above. */
}
/* Variant qualifiers don't affect the alias set, so get the main
- variant. Always use the canonical type as well.
- If this is a type with a known alias set, return it. */
+ variant. */
t = TYPE_MAIN_VARIANT (t);
- if (TYPE_CANONICAL (t))
- t = TYPE_CANONICAL (t);
+
+ /* Always use the canonical type as well. If this is a type that
+ requires structural comparisons to identify compatible types
+ use alias set zero. */
+ if (TYPE_STRUCTURAL_EQUALITY_P (t))
+ {
+ /* Allow the language to specify another alias set for this
+ type. */
+ set = lang_hooks.get_alias_set (t);
+ if (set != -1)
+ return set;
+ return 0;
+ }
+
+ t = TYPE_CANONICAL (t);
+
+ /* The canonical type should not require structural equality checks. */
+ gcc_checking_assert (!TYPE_STRUCTURAL_EQUALITY_P (t));
+
+ /* If this is a type with a known alias set, return it. */
if (TYPE_ALIAS_SET_KNOWN_P (t))
return TYPE_ALIAS_SET (t);
/* 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
- || TREE_CODE (t) == METHOD_TYPE)
+ else if (TREE_CODE (t) == FUNCTION_TYPE || TREE_CODE (t) == METHOD_TYPE)
set = 0;
/* Unless the language specifies otherwise, let vector types alias
integer(kind=4)[4] the same alias set or not.
Just be pragmatic here and make sure the array and its element
type get the same alias set assigned. */
- else if (TREE_CODE (t) == ARRAY_TYPE
- && !TYPE_NONALIASED_COMPONENT (t))
+ else if (TREE_CODE (t) == ARRAY_TYPE && !TYPE_NONALIASED_COMPONENT (t))
set = get_alias_set (TREE_TYPE (t));
+ /* From the former common C and C++ langhook implementation:
+
+ Unfortunately, there is no canonical form of a pointer type.
+ In particular, if we have `typedef int I', then `int *', and
+ `I *' are different types. So, we have to pick a canonical
+ representative. We do this below.
+
+ Technically, this approach is actually more conservative that
+ it needs to be. In particular, `const int *' and `int *'
+ should be in different alias sets, according to the C and C++
+ standard, since their types are not the same, and so,
+ technically, an `int **' and `const int **' cannot point at
+ the same thing.
+
+ But, the standard is wrong. In particular, this code is
+ legal C++:
+
+ int *ip;
+ int **ipp = &ip;
+ const int* const* cipp = ipp;
+ And, it doesn't make sense for that to be legal unless you
+ can dereference IPP and CIPP. So, we ignore cv-qualifiers on
+ the pointed-to types. This issue has been reported to the
+ C++ committee.
+
+ In addition to the above canonicalization issue, with LTO
+ we should also canonicalize `T (*)[]' to `T *' avoiding
+ alias issues with pointer-to element types and pointer-to
+ array types.
+
+ Likewise we need to deal with the situation of incomplete
+ pointed-to types and make `*(struct X **)&a' and
+ `*(struct X {} **)&a' alias. Otherwise we will have to
+ guarantee that all pointer-to incomplete type variants
+ will be replaced by pointer-to complete type variants if
+ they are available.
+
+ With LTO the convenient situation of using `void *' to
+ access and store any pointer type will also become
+ more apparent (and `void *' is just another pointer-to
+ incomplete type). Assigning alias-set zero to `void *'
+ and all pointer-to incomplete types is a not appealing
+ solution. Assigning an effective alias-set zero only
+ affecting pointers might be - by recording proper subset
+ relationships of all pointer alias-sets.
+
+ Pointer-to function types are another grey area which
+ needs caution. Globbing them all into one alias-set
+ or the above effective zero set would work.
+
+ For now just assign the same alias-set to all pointers.
+ That's simple and avoids all the above problems. */
+ else if (POINTER_TYPE_P (t)
+ && t != ptr_type_node)
+ set = get_alias_set (ptr_type_node);
+
+ /* Otherwise make a new alias set for this type. */
else
- /* Otherwise make a new alias set for this type. */
- set = new_alias_set ();
+ {
+ /* Each canonical type gets its own alias set, so canonical types
+ shouldn't form a tree. It doesn't really matter for types
+ we handle specially above, so only check it where it possibly
+ would result in a bogus alias set. */
+ gcc_checking_assert (TYPE_CANONICAL (t) == t);
+
+ set = new_alias_set ();
+ }
TYPE_ALIAS_SET (t) = set;
- /* If this is an aggregate type, we must record any component aliasing
- information. */
+ /* If this is an aggregate type or a complex type, we must record any
+ component aliasing information. */
if (AGGREGATE_TYPE_P (t) || TREE_CODE (t) == COMPLEX_TYPE)
record_component_aliases (t);
{
/* Create an entry for the SUPERSET, so that we have a place to
attach the SUBSET. */
- superset_entry = GGC_NEW (struct alias_set_entry);
+ superset_entry = ggc_alloc_cleared_alias_set_entry_d ();
superset_entry->alias_set = superset;
superset_entry->children
- = splay_tree_new_ggc (splay_tree_compare_ints);
+ = splay_tree_new_ggc (splay_tree_compare_ints,
+ ggc_alloc_splay_tree_scalar_scalar_splay_tree_s,
+ ggc_alloc_splay_tree_scalar_scalar_splay_tree_node_s);
superset_entry->has_zero_child = 0;
VEC_replace (alias_set_entry, alias_sets, superset, superset_entry);
}
record_alias_subset (superset,
get_alias_set (BINFO_TYPE (base_binfo)));
}
- for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
+ for (field = TYPE_FIELDS (type); field != 0; field = DECL_CHAIN (field))
if (TREE_CODE (field) == FIELD_DECL && !DECL_NONADDRESSABLE_P (field))
record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
break;
/* 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. */
- if (GET_CODE (src_1) == CONST_INT || CONSTANT_P (src_0))
+ if (CONST_INT_P (src_1) || CONSTANT_P (src_0))
return find_base_value (src_0);
- else if (GET_CODE (src_0) == CONST_INT || CONSTANT_P (src_1))
+ else if (CONST_INT_P (src_0) || CONSTANT_P (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. */
- if (GET_CODE (XEXP (src, 1)) == CONST_INT && INTVAL (XEXP (src, 1)) != 0)
+ if (CONST_INT_P (XEXP (src, 1)) && INTVAL (XEXP (src, 1)) != 0)
return find_base_value (XEXP (src, 0));
return 0;
case TRUNCATE:
+ /* As we do not know which address space the pointer is refering to, we can
+ handle this only if the target does not support different pointer or
+ address modes depending on the address space. */
+ if (!target_default_pointer_address_modes_p ())
+ break;
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 */
+ /* As we do not know which address space the pointer is refering to, we can
+ handle this only if the target does not support different pointer or
+ address modes depending on the address space. */
+ if (!target_default_pointer_address_modes_p ())
+ break;
+
{
rtx temp = find_base_value (XEXP (src, 0));
regno = REGNO (dest);
- gcc_assert (regno < VEC_length (rtx, reg_base_value));
+ gcc_checking_assert (regno < VEC_length (rtx, reg_base_value));
/* If this spans multiple hard registers, then we must indicate that every
register has an unusable value. */
break;
}
case AND:
- if (XEXP (src, 0) != dest || GET_CODE (XEXP (src, 1)) != CONST_INT)
+ if (XEXP (src, 0) != dest || !CONST_INT_P (XEXP (src, 1)))
new_reg_base_value[regno] = 0;
break;
default:
reg_seen[regno] = 1;
}
+/* Return REG_BASE_VALUE for REGNO. Selective scheduler uses this to avoid
+ using hard registers with non-null REG_BASE_VALUE for renaming. */
+rtx
+get_reg_base_value (unsigned int regno)
+{
+ return VEC_index (rtx, reg_base_value, regno);
+}
+
/* If a value is known for REGNO, return it. */
rtx
if (x0 != XEXP (x, 0) || x1 != XEXP (x, 1))
{
- if (GET_CODE (x0) == CONST_INT)
+ if (CONST_INT_P (x0))
return plus_constant (x1, INTVAL (x0));
- else if (GET_CODE (x1) == CONST_INT)
+ else if (CONST_INT_P (x1))
return plus_constant (x0, INTVAL (x1));
return gen_rtx_PLUS (GET_MODE (x), x0, x1);
}
find_base_term (rtx x)
{
cselib_val *val;
- struct elt_loc_list *l;
+ struct elt_loc_list *l, *f;
+ rtx ret;
#if defined (FIND_BASE_TERM)
/* Try machine-dependent ways to find the base term. */
return REG_BASE_VALUE (x);
case TRUNCATE:
+ /* As we do not know which address space the pointer is refering to, we can
+ handle this only if the target does not support different pointer or
+ address modes depending on the address space. */
+ if (!target_default_pointer_address_modes_p ())
+ return 0;
if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (Pmode))
return 0;
/* Fall through. */
case ZERO_EXTEND:
case SIGN_EXTEND: /* Used for Alpha/NT pointers */
+ /* As we do not know which address space the pointer is refering to, we can
+ handle this only if the target does not support different pointer or
+ address modes depending on the address space. */
+ if (!target_default_pointer_address_modes_p ())
+ return 0;
+
{
rtx temp = find_base_term (XEXP (x, 0));
case VALUE:
val = CSELIB_VAL_PTR (x);
+ ret = NULL_RTX;
+
if (!val)
- return 0;
- for (l = val->locs; l; l = l->next)
- if ((x = find_base_term (l->loc)) != 0)
- return x;
- return 0;
+ return ret;
+
+ f = val->locs;
+ /* Temporarily reset val->locs to avoid infinite recursion. */
+ val->locs = NULL;
+
+ for (l = f; l; l = l->next)
+ if (GET_CODE (l->loc) == VALUE
+ && CSELIB_VAL_PTR (l->loc)->locs
+ && !CSELIB_VAL_PTR (l->loc)->locs->next
+ && CSELIB_VAL_PTR (l->loc)->locs->loc == x)
+ continue;
+ else if ((ret = find_base_term (l->loc)) != 0)
+ break;
+
+ val->locs = f;
+ return ret;
+
+ case LO_SUM:
+ /* The standard form is (lo_sum reg sym) so look only at the
+ second operand. */
+ return find_base_term (XEXP (x, 1));
case CONST:
x = XEXP (x, 0);
if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS)
return 0;
/* Fall through. */
- case LO_SUM:
- /* The standard form is (lo_sum reg sym) so look only at the
- second operand. */
- return find_base_term (XEXP (x, 1));
case PLUS:
case MINUS:
{
/* If either operand is known to be a pointer, then use it
to determine the base term. */
if (REG_P (tmp1) && REG_POINTER (tmp1))
- return find_base_term (tmp1);
+ {
+ rtx base = find_base_term (tmp1);
+ if (base)
+ return base;
+ }
if (REG_P (tmp2) && REG_POINTER (tmp2))
- return find_base_term (tmp2);
+ {
+ rtx base = find_base_term (tmp2);
+ if (base)
+ return base;
+ }
/* Neither operand was known to be a pointer. Go ahead and find the
base term for both operands. */
}
case AND:
- if (GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) != 0)
+ if (CONST_INT_P (XEXP (x, 1)) && INTVAL (XEXP (x, 1)) != 0)
return find_base_term (XEXP (x, 0));
return 0;
if (GET_CODE (x) == AND && GET_CODE (y) == AND)
return 1;
if (GET_CODE (x) == AND
- && (GET_CODE (XEXP (x, 1)) != CONST_INT
+ && (!CONST_INT_P (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
+ && (!CONST_INT_P (XEXP (y, 1))
|| (int) GET_MODE_UNIT_SIZE (x_mode) < -INTVAL (XEXP (y, 1))))
return 1;
|| (GET_CODE (y_base) == ADDRESS && GET_MODE (y_base) == Pmode))
return 0;
- if (! flag_argument_noalias)
+ return 1;
+}
+
+/* Callback for for_each_rtx, that returns 1 upon encountering a VALUE
+ whose UID is greater than the int uid that D points to. */
+
+static int
+refs_newer_value_cb (rtx *x, void *d)
+{
+ if (GET_CODE (*x) == VALUE && CSELIB_VAL_PTR (*x)->uid > *(int *)d)
return 1;
- if (flag_argument_noalias > 1)
- return 0;
+ return 0;
+}
+
+/* Return TRUE if EXPR refers to a VALUE whose uid is greater than
+ that of V. */
+
+static bool
+refs_newer_value_p (rtx expr, rtx v)
+{
+ int minuid = CSELIB_VAL_PTR (v)->uid;
- /* Weak noalias assertion (arguments are distinct, but may match globals). */
- return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode);
+ return for_each_rtx (&expr, refs_newer_value_cb, &minuid);
}
/* Convert the address X into something we can use. This is done by returning
v = CSELIB_VAL_PTR (x);
if (v)
{
+ bool have_equivs = cselib_have_permanent_equivalences ();
+ if (have_equivs)
+ v = canonical_cselib_val (v);
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 (!REG_P (l->loc) && !MEM_P (l->loc))
+ if (!REG_P (l->loc) && !MEM_P (l->loc)
+ /* Avoid infinite recursion when potentially dealing with
+ var-tracking artificial equivalences, by skipping the
+ equivalences themselves, and not choosing expressions
+ that refer to newer VALUEs. */
+ && (!have_equivs
+ || (GET_CODE (l->loc) != VALUE
+ && !refs_newer_value_p (l->loc, x))))
return l->loc;
+ if (have_equivs)
+ {
+ for (l = v->locs; l; l = l->next)
+ if (REG_P (l->loc)
+ || (GET_CODE (l->loc) != VALUE
+ && !refs_newer_value_p (l->loc, x)))
+ return l->loc;
+ /* Return the canonical value. */
+ return v->val_rtx;
+ }
if (v->locs)
return v->locs->loc;
}
return addr;
}
-/* Return nonzero if X and Y (memory addresses) could reference the
- same location in memory. C is an offset accumulator. When
+/* Return one if X and Y (memory addresses) reference the
+ same location in memory or if the references overlap.
+ Return zero if they do not overlap, else return
+ minus one in which case they still might reference the same location.
+
+ C is an offset accumulator. When
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.
align memory references, as is done on the Alpha.
Nice to notice that varying addresses cannot conflict with fp if no
- local variables had their addresses taken, but that's too hard now. */
+ local variables had their addresses taken, but that's too hard now.
+
+ ??? Contrary to the tree alias oracle this does not return
+ one for X + non-constant and Y + non-constant when X and Y are equal.
+ If that is fixed the TBAA hack for union type-punning can be removed. */
static int
memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
{
if (GET_CODE (x) == VALUE)
- x = get_addr (x);
+ {
+ if (REG_P (y))
+ {
+ struct elt_loc_list *l = NULL;
+ if (CSELIB_VAL_PTR (x))
+ for (l = canonical_cselib_val (CSELIB_VAL_PTR (x))->locs;
+ l; l = l->next)
+ if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y))
+ break;
+ if (l)
+ x = y;
+ else
+ x = get_addr (x);
+ }
+ /* Don't call get_addr if y is the same VALUE. */
+ else if (x != y)
+ x = get_addr (x);
+ }
if (GET_CODE (y) == VALUE)
- y = get_addr (y);
+ {
+ if (REG_P (x))
+ {
+ struct elt_loc_list *l = NULL;
+ if (CSELIB_VAL_PTR (y))
+ for (l = canonical_cselib_val (CSELIB_VAL_PTR (y))->locs;
+ l; l = l->next)
+ if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x))
+ break;
+ if (l)
+ y = x;
+ else
+ y = get_addr (y);
+ }
+ /* Don't call get_addr if x is the same VALUE. */
+ else if (y != x)
+ 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, x0, ysize, y0, c);
if (rtx_equal_for_memref_p (x0, y0))
return memrefs_conflict_p (xsize, x1, ysize, y1, c);
- if (GET_CODE (x1) == CONST_INT)
+ if (CONST_INT_P (x1))
{
- if (GET_CODE (y1) == CONST_INT)
+ if (CONST_INT_P (y1))
return memrefs_conflict_p (xsize, x0, ysize, y0,
c - INTVAL (x1) + INTVAL (y1));
else
return memrefs_conflict_p (xsize, x0, ysize, y,
c - INTVAL (x1));
}
- else if (GET_CODE (y1) == CONST_INT)
+ else if (CONST_INT_P (y1))
return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
- return 1;
+ return -1;
}
- else if (GET_CODE (x1) == CONST_INT)
+ else if (CONST_INT_P (x1))
return memrefs_conflict_p (xsize, x0, ysize, y, c - INTVAL (x1));
}
else if (GET_CODE (y) == PLUS)
rtx y0 = XEXP (y, 0);
rtx y1 = XEXP (y, 1);
- if (GET_CODE (y1) == CONST_INT)
+ if (CONST_INT_P (y1))
return memrefs_conflict_p (xsize, x, ysize, y0, c + INTVAL (y1));
else
- return 1;
+ return -1;
}
if (GET_CODE (x) == GET_CODE (y))
rtx x1 = canon_rtx (XEXP (x, 1));
rtx y1 = canon_rtx (XEXP (y, 1));
if (! rtx_equal_for_memref_p (x1, y1))
- return 1;
+ return -1;
x0 = canon_rtx (XEXP (x, 0));
y0 = canon_rtx (XEXP (y, 0));
if (rtx_equal_for_memref_p (x0, y0))
|| (c >= 0 && xsize > c) || (c < 0 && ysize+c > 0));
/* Can't properly adjust our sizes. */
- if (GET_CODE (x1) != CONST_INT)
- return 1;
+ if (!CONST_INT_P (x1))
+ return -1;
xsize /= INTVAL (x1);
ysize /= INTVAL (x1);
c /= INTVAL (x1);
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 (x) == AND && CONST_INT_P (XEXP (x, 1)))
{
if (GET_CODE (y) == AND || ysize < -INTVAL (XEXP (x, 1)))
xsize = -1;
return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), ysize, y, c);
}
- if (GET_CODE (y) == AND && GET_CODE (XEXP (y, 1)) == CONST_INT)
+ if (GET_CODE (y) == AND && CONST_INT_P (XEXP (y, 1)))
{
/* ??? If we are indexing far enough into the array/structure, we
may yet be able to determine that we can not overlap. But we
if (CONSTANT_P (x))
{
- if (GET_CODE (x) == CONST_INT && GET_CODE (y) == CONST_INT)
+ if (CONST_INT_P (x) && CONST_INT_P (y))
{
c += (INTVAL (y) - INTVAL (x));
return (xsize <= 0 || ysize <= 0
|| (rtx_equal_for_memref_p (x, y)
&& ((c >= 0 && xsize > c) || (c < 0 && ysize+c > 0))));
- return 1;
+ return -1;
}
- return 1;
+
+ return -1;
}
/* Functions to compute memory dependencies.
changed. A volatile and non-volatile reference can be interchanged
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
- 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
+ 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
return MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem);
}
-/* Returns MEM1 if and only if MEM1 is a scalar at a fixed address and
- MEM2 is a reference to a structure at a varying address, or returns
- MEM2 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
- nonzero whenever variation is possible.
- MEM1_ADDR and MEM2_ADDR are the addresses of MEM1 and MEM2. */
-
-static const_rtx
-fixed_scalar_and_varying_struct_p (const_rtx mem1, const_rtx mem2, rtx mem1_addr,
- rtx mem2_addr,
- bool (*varies_p) (const_rtx, bool))
-{
- if (! flag_strict_aliasing)
- return NULL_RTX;
-
- if (MEM_ALIAS_SET (mem2)
- && 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_ALIAS_SET (mem1)
- && 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. */
- return mem2;
-
- return NULL_RTX;
-}
-
/* Returns nonzero if something about the mode or address format MEM1
indicates that it might well alias *anything*. */
{
const_tree fieldx, fieldy, typex, typey, orig_y;
+ if (!flag_strict_aliasing)
+ return false;
+
do
{
/* The comparison has to be done at a common type, since we don't
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. */
+/* Walk up the COMPONENT_REF list in X and adjust *OFFSET to compensate
+ for the offset of the field reference. *KNOWN_P says whether the
+ offset is known. */
-static rtx
-adjust_offset_for_component_ref (tree x, rtx offset)
+static void
+adjust_offset_for_component_ref (tree x, bool *known_p,
+ HOST_WIDE_INT *offset)
{
- HOST_WIDE_INT ioffset;
-
- if (! offset)
- return NULL_RTX;
-
- ioffset = INTVAL (offset);
+ if (!*known_p)
+ return;
do
{
- tree offset = component_ref_field_offset (x);
+ tree xoffset = component_ref_field_offset (x);
tree field = TREE_OPERAND (x, 1);
- if (! host_integerp (offset, 1))
- return NULL_RTX;
- ioffset += (tree_low_cst (offset, 1)
+ if (! host_integerp (xoffset, 1))
+ {
+ *known_p = false;
+ return;
+ }
+ *offset += (tree_low_cst (xoffset, 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. */
+ X and Y and they do not overlap.
+ If LOOP_VARIANT is set, skip offset-based disambiguation */
int
-nonoverlapping_memrefs_p (const_rtx x, const_rtx y)
+nonoverlapping_memrefs_p (const_rtx x, const_rtx y, bool loop_invariant)
{
tree exprx = MEM_EXPR (x), expry = MEM_EXPR (y);
rtx rtlx, rtly;
rtx basex, basey;
- rtx moffsetx, moffsety;
+ bool moffsetx_known_p, moffsety_known_p;
+ HOST_WIDE_INT moffsetx = 0, moffsety = 0;
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;
+ /* For spill-slot accesses make sure we have valid offsets. */
+ if ((exprx == get_spill_slot_decl (false)
+ && ! MEM_OFFSET_KNOWN_P (x))
+ || (expry == get_spill_slot_decl (false)
+ && ! MEM_OFFSET_KNOWN_P (y)))
+ 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
/* If the field reference test failed, look at the DECLs involved. */
- moffsetx = MEM_OFFSET (x);
+ moffsetx_known_p = MEM_OFFSET_KNOWN_P (x);
+ if (moffsetx_known_p)
+ moffsetx = MEM_OFFSET (x);
if (TREE_CODE (exprx) == COMPONENT_REF)
{
- if (TREE_CODE (expry) == VAR_DECL
- && POINTER_TYPE_P (TREE_TYPE (expry)))
- {
- tree field = TREE_OPERAND (exprx, 1);
- tree fieldcontext = DECL_FIELD_CONTEXT (field);
- if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
- TREE_TYPE (field)))
- return 1;
- }
- {
- tree t = decl_for_component_ref (exprx);
- if (! t)
- return 0;
- moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
- exprx = t;
- }
- }
- else if (INDIRECT_REF_P (exprx))
- {
- exprx = TREE_OPERAND (exprx, 0);
- if (flag_argument_noalias < 2
- || TREE_CODE (exprx) != PARM_DECL)
+ tree t = decl_for_component_ref (exprx);
+ if (! t)
return 0;
+ adjust_offset_for_component_ref (exprx, &moffsetx_known_p, &moffsetx);
+ exprx = t;
}
- moffsety = MEM_OFFSET (y);
+ moffsety_known_p = MEM_OFFSET_KNOWN_P (y);
+ if (moffsety_known_p)
+ moffsety = MEM_OFFSET (y);
if (TREE_CODE (expry) == COMPONENT_REF)
{
- if (TREE_CODE (exprx) == VAR_DECL
- && POINTER_TYPE_P (TREE_TYPE (exprx)))
- {
- tree field = TREE_OPERAND (expry, 1);
- tree fieldcontext = DECL_FIELD_CONTEXT (field);
- if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
- TREE_TYPE (field)))
- return 1;
- }
- {
- tree t = decl_for_component_ref (expry);
- if (! t)
- return 0;
- moffsety = adjust_offset_for_component_ref (expry, moffsety);
- expry = t;
- }
- }
- else if (INDIRECT_REF_P (expry))
- {
- expry = TREE_OPERAND (expry, 0);
- if (flag_argument_noalias < 2
- || TREE_CODE (expry) != PARM_DECL)
+ tree t = decl_for_component_ref (expry);
+ if (! t)
return 0;
+ adjust_offset_for_component_ref (expry, &moffsety_known_p, &moffsety);
+ expry = t;
}
if (! DECL_P (exprx) || ! DECL_P (expry))
return 0;
+ /* With invalid code we can end up storing into the constant pool.
+ Bail out to avoid ICEing when creating RTL for this.
+ See gfortran.dg/lto/20091028-2_0.f90. */
+ if (TREE_CODE (exprx) == CONST_DECL
+ || TREE_CODE (expry) == CONST_DECL)
+ return 1;
+
rtlx = DECL_RTL (exprx);
rtly = DECL_RTL (expry);
&& ! rtx_equal_p (rtlx, rtly))
return 1;
+ /* If we have MEMs refering to different address spaces (which can
+ potentially overlap), we cannot easily tell from the addresses
+ whether the references overlap. */
+ if (MEM_P (rtlx) && MEM_P (rtly)
+ && MEM_ADDR_SPACE (rtlx) != MEM_ADDR_SPACE (rtly))
+ return 0;
+
/* 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 = MEM_P (rtlx) ? XEXP (rtlx, 0) : rtlx;
- if (GET_CODE (basex) == PLUS && GET_CODE (XEXP (basex, 1)) == CONST_INT)
+ if (GET_CODE (basex) == PLUS && CONST_INT_P (XEXP (basex, 1)))
offsetx = INTVAL (XEXP (basex, 1)), basex = XEXP (basex, 0);
basey = MEM_P (rtly) ? XEXP (rtly, 0) : rtly;
- if (GET_CODE (basey) == PLUS && GET_CODE (XEXP (basey, 1)) == CONST_INT)
+ if (GET_CODE (basey) == PLUS && CONST_INT_P (XEXP (basey, 1)))
offsety = INTVAL (XEXP (basey, 1)), basey = XEXP (basey, 0);
/* If the bases are different, we know they do not overlap if both
|| (CONSTANT_P (basey) && REG_P (basex)
&& REGNO_PTR_FRAME_P (REGNO (basex))));
+ /* Offset based disambiguation not appropriate for loop invariant */
+ if (loop_invariant)
+ return 0;
+
sizex = (!MEM_P (rtlx) ? (int) GET_MODE_SIZE (GET_MODE (rtlx))
- : MEM_SIZE (rtlx) ? INTVAL (MEM_SIZE (rtlx))
+ : MEM_SIZE_KNOWN_P (rtlx) ? MEM_SIZE (rtlx)
: -1);
sizey = (!MEM_P (rtly) ? (int) GET_MODE_SIZE (GET_MODE (rtly))
- : MEM_SIZE (rtly) ? INTVAL (MEM_SIZE (rtly)) :
- -1);
+ : MEM_SIZE_KNOWN_P (rtly) ? 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 (moffsetx_known_p)
+ offsetx += moffsetx, sizex -= moffsetx;
+ if (moffsety_known_p)
+ offsety += moffsety, sizey -= 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));
+ if (MEM_SIZE_KNOWN_P (x) && moffsetx_known_p)
+ sizex = MEM_SIZE (x);
+ if (MEM_SIZE_KNOWN_P (y) && moffsety_known_p)
+ sizey = MEM_SIZE (y);
/* Put the values of the memref with the lower offset in X's values. */
if (offsetx > offsety)
return sizex >= 0 && offsety >= offsetx + sizex;
}
-/* True dependence: X is read after store in MEM takes place. */
+/* Helper for true_dependence and canon_true_dependence.
+ Checks for true dependence: X is read after store in MEM takes place.
-int
-true_dependence (const_rtx mem, enum machine_mode mem_mode, const_rtx x,
- bool (*varies) (const_rtx, bool))
+ If MEM_CANONICALIZED is FALSE, then X_ADDR and MEM_ADDR should be
+ NULL_RTX, and the canonical addresses of MEM and X are both computed
+ here. If MEM_CANONICALIZED, then MEM must be already canonicalized.
+
+ If X_ADDR is non-NULL, it is used in preference of XEXP (x, 0).
+
+ Returns 1 if there is a true dependence, 0 otherwise. */
+
+static int
+true_dependence_1 (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr,
+ const_rtx x, rtx x_addr, bool mem_canonicalized)
{
- rtx x_addr, mem_addr;
rtx base;
+ int ret;
+
+ gcc_checking_assert (mem_canonicalized ? (mem_addr != NULL_RTX)
+ : (mem_addr == NULL_RTX && x_addr == NULL_RTX));
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
return 1;
- if (DIFFERENT_ALIAS_SETS_P (x, mem))
- return 0;
-
/* Read-only memory is by definition never modified, and therefore can't
conflict with anything. We don't expect to find read-only set on MEM,
but stupid user tricks can produce them, so don't die. */
if (MEM_READONLY_P (x))
return 0;
- if (nonoverlapping_memrefs_p (mem, x))
- return 0;
+ /* If we have MEMs refering to different address spaces (which can
+ potentially overlap), we cannot easily tell from the addresses
+ whether the references overlap. */
+ if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
+ return 1;
- if (mem_mode == VOIDmode)
- mem_mode = GET_MODE (mem);
+ if (! mem_addr)
+ {
+ mem_addr = XEXP (mem, 0);
+ if (mem_mode == VOIDmode)
+ mem_mode = GET_MODE (mem);
+ }
- x_addr = get_addr (XEXP (x, 0));
- mem_addr = get_addr (XEXP (mem, 0));
+ if (! x_addr)
+ {
+ x_addr = XEXP (x, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ if (! mem_canonicalized)
+ mem_addr = get_addr (mem_addr);
+ }
+ }
base = find_base_term (x_addr);
if (base && (GET_CODE (base) == LABEL_REF
return 0;
x_addr = canon_rtx (x_addr);
- mem_addr = canon_rtx (mem_addr);
+ if (!mem_canonicalized)
+ mem_addr = canon_rtx (mem_addr);
+
+ if ((ret = memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
+ SIZE_FOR_MODE (x), x_addr, 0)) != -1)
+ return ret;
+
+ if (DIFFERENT_ALIAS_SETS_P (x, mem))
+ return 0;
- if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
- SIZE_FOR_MODE (x), x_addr, 0))
+ if (nonoverlapping_memrefs_p (mem, x, false))
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)
+ at MEM_ADDR, rather than XEXP (mem, 0). */
+ if (GET_CODE (mem_addr) == AND)
return 1;
- /* In true_dependence we also allow BLKmode to alias anything. Why
+ /* ??? In true_dependence we also allow BLKmode to alias anything. Why
don't we do this in anti_dependence and output_dependence? */
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
return 1;
- return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
- varies);
+ return rtx_refs_may_alias_p (x, mem, true);
+}
+
+/* True dependence: X is read after store in MEM takes place. */
+
+int
+true_dependence (const_rtx mem, enum machine_mode mem_mode, const_rtx x)
+{
+ return true_dependence_1 (mem, mem_mode, NULL_RTX,
+ x, NULL_RTX, /*mem_canonicalized=*/false);
}
/* 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
+ The mem_addr argument has been added, since true_dependence_1 computed
this value prior to canonicalizing. */
int
canon_true_dependence (const_rtx mem, enum machine_mode mem_mode, rtx mem_addr,
- const_rtx x, bool (*varies) (const_rtx, bool))
+ const_rtx x, 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 (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
- || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
- return 1;
-
- if (DIFFERENT_ALIAS_SETS_P (x, mem))
- return 0;
-
- /* Read-only memory is by definition never modified, and therefore can't
- conflict with anything. We don't expect to find read-only set on MEM,
- but stupid user tricks can produce them, so don't die. */
- if (MEM_READONLY_P (x))
- 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))
- 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_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);
+ return true_dependence_1 (mem, mem_mode, mem_addr,
+ x, x_addr, /*mem_canonicalized=*/true);
}
/* Returns nonzero if a write to X might alias a previous read from
write_dependence_p (const_rtx mem, const_rtx x, int writep)
{
rtx x_addr, mem_addr;
- const_rtx fixed_scalar;
rtx base;
+ int ret;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
|| MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
return 1;
- if (DIFFERENT_ALIAS_SETS_P (x, mem))
- return 0;
-
/* A read from read-only memory can't conflict with read-write memory. */
if (!writep && MEM_READONLY_P (mem))
return 0;
- if (nonoverlapping_memrefs_p (x, mem))
- return 0;
+ /* If we have MEMs refering to different address spaces (which can
+ potentially overlap), we cannot easily tell from the addresses
+ whether the references overlap. */
+ if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
+ return 1;
- x_addr = get_addr (XEXP (x, 0));
- mem_addr = get_addr (XEXP (mem, 0));
+ x_addr = XEXP (x, 0);
+ mem_addr = XEXP (mem, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ mem_addr = get_addr (mem_addr);
+ }
if (! writep)
{
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;
+ if ((ret = memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr,
+ SIZE_FOR_MODE (x), x_addr, 0)) != -1)
+ return ret;
- fixed_scalar
- = fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
- rtx_addr_varies_p);
+ if (nonoverlapping_memrefs_p (x, mem, false))
+ return 0;
- return (!(fixed_scalar == mem && !aliases_everything_p (x))
- && !(fixed_scalar == x && !aliases_everything_p (mem)));
+ return rtx_refs_may_alias_p (x, mem, false);
}
/* Anti dependence: X is written after read in MEM takes place. */
}
\f
+
+/* Check whether X may be aliased with MEM. Don't do offset-based
+ memory disambiguation & TBAA. */
+int
+may_alias_p (const_rtx mem, const_rtx x)
+{
+ rtx x_addr, mem_addr;
+
+ if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
+ return 1;
+
+ /* ??? In true_dependence we also allow BLKmode to alias anything. */
+ if (GET_MODE (mem) == BLKmode || GET_MODE (x) == BLKmode)
+ return 1;
+
+ if (MEM_ALIAS_SET (x) == ALIAS_SET_MEMORY_BARRIER
+ || MEM_ALIAS_SET (mem) == ALIAS_SET_MEMORY_BARRIER)
+ return 1;
+
+ /* Read-only memory is by definition never modified, and therefore can't
+ conflict with anything. We don't expect to find read-only set on MEM,
+ but stupid user tricks can produce them, so don't die. */
+ if (MEM_READONLY_P (x))
+ return 0;
+
+ /* If we have MEMs refering to different address spaces (which can
+ potentially overlap), we cannot easily tell from the addresses
+ whether the references overlap. */
+ if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
+ return 1;
+
+ x_addr = XEXP (x, 0);
+ mem_addr = XEXP (mem, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ mem_addr = get_addr (mem_addr);
+ }
+
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), GET_MODE (mem_addr)))
+ return 0;
+
+ x_addr = canon_rtx (x_addr);
+ mem_addr = canon_rtx (mem_addr);
+
+ if (nonoverlapping_memrefs_p (mem, x, true))
+ return 0;
+
+ if (aliases_everything_p (x))
+ return 1;
+
+ /* We cannot use aliases_everything_p to test MEM, since we must look
+ at MEM_ADDR, rather than XEXP (mem, 0). */
+ if (GET_CODE (mem_addr) == AND)
+ return 1;
+
+ /* TBAA not valid for loop_invarint */
+ return rtx_refs_may_alias_p (x, mem, false);
+}
+
void
init_alias_target (void)
{
= 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
+#if !HARD_FRAME_POINTER_IS_FRAME_POINTER
static_reg_base_value[HARD_FRAME_POINTER_REGNUM]
= gen_rtx_ADDRESS (Pmode, hard_frame_pointer_rtx);
#endif
timevar_push (TV_ALIAS_ANALYSIS);
reg_known_value_size = maxreg - FIRST_PSEUDO_REGISTER;
- reg_known_value = GGC_CNEWVEC (rtx, reg_known_value_size);
+ reg_known_value = ggc_alloc_cleared_vec_rtx (reg_known_value_size);
reg_known_equiv_p = XCNEWVEC (bool, reg_known_value_size);
/* If we have memory allocated from the previous run, use it. */
&& GET_CODE (src) == PLUS
&& REG_P (XEXP (src, 0))
&& (t = get_reg_known_value (REGNO (XEXP (src, 0))))
- && GET_CODE (XEXP (src, 1)) == CONST_INT)
+ && CONST_INT_P (XEXP (src, 1)))
{
t = plus_constant (t, INTVAL (XEXP (src, 1)));
set_reg_known_value (regno, t);
timevar_pop (TV_ALIAS_ANALYSIS);
}
+/* Equate REG_BASE_VALUE (reg1) to REG_BASE_VALUE (reg2).
+ Special API for var-tracking pass purposes. */
+
+void
+vt_equate_reg_base_value (const_rtx reg1, const_rtx reg2)
+{
+ VEC_replace (rtx, reg_base_value, REGNO (reg1), REG_BASE_VALUE (reg2));
+}
+
void
end_alias_analysis (void)
{
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