#include "flags.h"
#include "output.h"
#include "toplev.h"
+#include "cselib.h"
#include "splay-tree.h"
#include "ggc.h"
/* The alias sets assigned to MEMs assist the back-end in determining
which MEMs can alias which other MEMs. In general, two MEMs in
- different alias sets to not alias each other. There is one
- exception, however. Consider something like:
+ different alias sets cannot alias each other, with one important
+ exception. Consider something like:
struct S {int i; double d; };
|/_ _\|
int double
- (The arrows are directed and point downwards.) If, when comparing
- two alias sets, we can hold one set fixed, trace the other set
- downwards, and at some point find the first set, the two MEMs can
- alias one another. In this situation we say the alias set for
- `struct S' is the `superset' and that those for `int' and `double'
- are `subsets'.
+ (The arrows are directed and point downwards.)
+ In this situation we say the alias set for `struct S' is the
+ `superset' and that those for `int' and `double' are `subsets'.
+
+ To see whether two alias sets can point to the same memory, we must
+ see if either alias set is a subset of the other. We need not trace
+ past immediate decendents, however, since we propagate all
+ grandchildren up one level.
Alias set zero is implicitly a superset of all other alias sets.
However, this is no actual entry for alias set zero. It is an
typedef struct alias_set_entry
{
/* The alias set number, as stored in MEM_ALIAS_SET. */
- int alias_set;
+ HOST_WIDE_INT alias_set;
/* The children of the alias set. These are not just the immediate
- children, but, in fact, all children. So, if we have:
+ children, but, in fact, all decendents. So, if we have:
struct T { struct S s; float f; }
continuing our example above, the children here will be all of
`int', `double', `float', and `struct S'. */
splay_tree children;
+
+ /* Nonzero if would have a child of zero: this effectively makes this
+ alias set the same as alias set zero. */
+ int has_zero_child;
} *alias_set_entry;
-static rtx canon_rtx PARAMS ((rtx));
static int rtx_equal_for_memref_p PARAMS ((rtx, rtx));
static rtx find_symbolic_term PARAMS ((rtx));
+static rtx get_addr PARAMS ((rtx));
static int memrefs_conflict_p PARAMS ((int, rtx, int, rtx,
HOST_WIDE_INT));
static void record_set PARAMS ((rtx, rtx, void *));
static rtx find_base_value PARAMS ((rtx));
static int mems_in_disjoint_alias_sets_p PARAMS ((rtx, rtx));
static int insert_subset_children PARAMS ((splay_tree_node, void*));
-static alias_set_entry get_alias_set_entry PARAMS ((int));
-static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, int (*)(rtx)));
+static tree find_base_decl PARAMS ((tree));
+static alias_set_entry get_alias_set_entry PARAMS ((HOST_WIDE_INT));
+static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, rtx, rtx,
+ int (*) (rtx)));
static int aliases_everything_p PARAMS ((rtx));
static int write_dependence_p PARAMS ((rtx, rtx, int));
static int nonlocal_reference_p PARAMS ((rtx));
mems_in_disjoint_alias_sets_p (MEM1, MEM2)
/* Cap the number of passes we make over the insns propagating alias
- information through set chains.
-
- 10 is a completely arbitrary choice. */
+ information through set chains. 10 is a completely arbitrary choice. */
#define MAX_ALIAS_LOOP_PASSES 10
/* reg_base_value[N] gives an address to which register N is related.
static unsigned int reg_base_value_size; /* size of reg_base_value array */
#define REG_BASE_VALUE(X) \
- ((unsigned) REGNO (X) < reg_base_value_size ? reg_base_value[REGNO (X)] : 0)
+ (REGNO (X) < reg_base_value_size ? reg_base_value[REGNO (X)] : 0)
/* Vector of known invariant relationships between registers. Set in
loop unrolling. Indexed by register number, if nonzero the value
after reload. */
static rtx *alias_invariant;
-/* Vector indexed by N giving the initial (unchanging) value known
- for pseudo-register N. */
+/* Vector indexed by N giving the initial (unchanging) value known for
+ pseudo-register N. This array is initialized in
+ init_alias_analysis, and does not change until end_alias_analysis
+ is called. */
rtx *reg_known_value;
/* Indicates number of valid entries in reg_known_value. */
-static int reg_known_value_size;
+static unsigned int reg_known_value_size;
/* Vector recording for each reg_known_value whether it is due to a
REG_EQUIV note. Future passes (viz., reload) may replace the
pseudo with the equivalent expression and so we account for the
- dependences that would be introduced if that happens. */
-/* ??? This is a problem only on the Convex. The REG_EQUIV notes created in
- assign_parms mention the arg pointer, and there are explicit insns in the
- RTL that modify the arg pointer. Thus we must ensure that such insns don't
- get scheduled across each other because that would invalidate the REG_EQUIV
- notes. One could argue that the REG_EQUIV notes are wrong, but solving
- the problem in the scheduler will likely give better code, so we do it
- here. */
+ dependences that would be introduced if that happens.
+
+ The REG_EQUIV notes created in assign_parms may mention the arg
+ pointer, and there are explicit insns in the RTL that modify the
+ arg pointer. Thus we must ensure that such insns don't get
+ scheduled across each other because that would invalidate the
+ REG_EQUIV notes. One could argue that the REG_EQUIV notes are
+ wrong, but solving the problem in the scheduler will likely give
+ better code, so we do it here. */
char *reg_known_equiv_p;
/* True when scanning insns from the start of the rtl to the
NOTE_INSN_FUNCTION_BEG note. */
-
static int copying_arguments;
/* The splay-tree used to store the various alias set entries. */
-
static splay_tree alias_sets;
-
+\f
/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
such an entry, or NULL otherwise. */
static alias_set_entry
get_alias_set_entry (alias_set)
- int alias_set;
+ HOST_WIDE_INT alias_set;
{
splay_tree_node sn
= splay_tree_lookup (alias_sets, (splay_tree_key) alias_set);
return sn != 0 ? ((alias_set_entry) sn->value) : 0;
}
-/* Returns nonzero value if the alias sets for MEM1 and MEM2 are such
- that the two MEMs cannot alias each other. */
+/* Returns nonzero if the alias sets for MEM1 and MEM2 are such that
+ the two MEMs cannot alias each other. */
static int
mems_in_disjoint_alias_sets_p (mem1, mem2)
if (MEM_ALIAS_SET (mem1) == MEM_ALIAS_SET (mem2))
return 0;
- /* Iterate through each of the children of the first alias set,
- comparing it with the second alias set. */
+ /* See if the first alias set is a subset of the second. */
ase = get_alias_set_entry (MEM_ALIAS_SET (mem1));
- if (ase != 0 && splay_tree_lookup (ase->children,
- (splay_tree_key) MEM_ALIAS_SET (mem2)))
+ if (ase != 0
+ && (ase->has_zero_child
+ || splay_tree_lookup (ase->children,
+ (splay_tree_key) MEM_ALIAS_SET (mem2))))
return 0;
/* Now do the same, but with the alias sets reversed. */
ase = get_alias_set_entry (MEM_ALIAS_SET (mem2));
- if (ase != 0 && splay_tree_lookup (ase->children,
- (splay_tree_key) MEM_ALIAS_SET (mem1)))
+ if (ase != 0
+ && (ase->has_zero_child
+ || splay_tree_lookup (ase->children,
+ (splay_tree_key) MEM_ALIAS_SET (mem1))))
return 0;
/* The two MEMs are in distinct alias sets, and neither one is the
return 0;
}
+\f
+/* T is an expression with pointer type. Find the DECL on which this
+ expression is based. (For example, in `a[i]' this would be `a'.)
+ If there is no such DECL, or a unique decl cannot be determined,
+ NULL_TREE is retured. */
+
+static tree
+find_base_decl (t)
+ tree t;
+{
+ tree d0, d1, d2;
+
+ if (t == 0 || t == error_mark_node || ! POINTER_TYPE_P (TREE_TYPE (t)))
+ return 0;
+
+ /* If this is a declaration, return it. */
+ if (TREE_CODE_CLASS (TREE_CODE (t)) == 'd')
+ return t;
+
+ /* Handle general expressions. It would be nice to deal with
+ COMPONENT_REFs here. If we could tell that `a' and `b' were the
+ same, then `a->f' and `b->f' are also the same. */
+ switch (TREE_CODE_CLASS (TREE_CODE (t)))
+ {
+ case '1':
+ return find_base_decl (TREE_OPERAND (t, 0));
+
+ case '2':
+ /* Return 0 if found in neither or both are the same. */
+ d0 = find_base_decl (TREE_OPERAND (t, 0));
+ d1 = find_base_decl (TREE_OPERAND (t, 1));
+ if (d0 == d1)
+ return d0;
+ else if (d0 == 0)
+ return d1;
+ else if (d1 == 0)
+ return d0;
+ else
+ return 0;
+
+ case '3':
+ d0 = find_base_decl (TREE_OPERAND (t, 0));
+ d1 = find_base_decl (TREE_OPERAND (t, 1));
+ d0 = find_base_decl (TREE_OPERAND (t, 0));
+ d2 = find_base_decl (TREE_OPERAND (t, 2));
+
+ /* Set any nonzero values from the last, then from the first. */
+ if (d1 == 0) d1 = d2;
+ if (d0 == 0) d0 = d1;
+ if (d1 == 0) d1 = d0;
+ if (d2 == 0) d2 = d1;
+
+ /* At this point all are nonzero or all are zero. If all three are the
+ same, return it. Otherwise, return zero. */
+ return (d0 == d1 && d1 == d2) ? d0 : 0;
+
+ default:
+ return 0;
+ }
+}
+
+/* Return the alias set for T, which may be either a type or an
+ expression. Call language-specific routine for help, if needed. */
+
+HOST_WIDE_INT
+get_alias_set (t)
+ tree t;
+{
+ tree orig_t;
+ HOST_WIDE_INT set;
+ HOST_WIDE_INT bitsize, bitpos;
+ tree offset;
+ enum machine_mode mode;
+ int volatilep, unsignedp;
+ unsigned int alignment;
+
+ /* If we're not doing any alias analysis, just assume everything
+ aliases everything else. Also return 0 if this or its type is
+ an error. */
+ if (! flag_strict_aliasing || t == error_mark_node
+ || (! TYPE_P (t)
+ && (TREE_TYPE (t) == 0 || TREE_TYPE (t) == error_mark_node)))
+ return 0;
+
+ /* We can be passed either an expression or a type. This and the
+ language-specific routine may make mutually-recursive calls to
+ each other to figure out what to do. At each juncture, we see if
+ this is a tree that the language may need to handle specially.
+ First handle things that aren't types and start by removing nops
+ since we care only about the actual object. */
+ 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)
+ return set;
+
+ /* If this is a reference, go inside it and use the underlying
+ object. */
+ if (TREE_CODE_CLASS (TREE_CODE (t)) == 'r')
+ t = get_inner_reference (t, &bitsize, &bitpos, &offset, &mode,
+ &unsignedp, &volatilep, &alignment);
+
+ if (TREE_CODE (t) == INDIRECT_REF)
+ {
+ /* Check for accesses through restrict-qualified pointers. */
+ tree decl = find_base_decl (TREE_OPERAND (t, 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 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)
+ return 0;
+ }
+
+ /* 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))
+ 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);
+ }
+
+ /* There are no objects of FUNCTION_TYPE, so there's no point in
+ using up an alias set for them. (There are, of course, pointers
+ and references to functions, but that's different.) */
+ else if (TREE_CODE (t) == FUNCTION_TYPE)
+ set = 0;
+ else
+ /* Otherwise make a new alias set for this type. */
+ set = new_alias_set ();
+
+ TYPE_ALIAS_SET (t) = set;
+
+ /* If this is an aggregate type, we must record any component aliasing
+ information. */
+ if (AGGREGATE_TYPE_P (t))
+ record_component_aliases (t);
+
+ return set;
+}
+
+/* Return a brand-new alias set. */
+
+HOST_WIDE_INT
+new_alias_set ()
+{
+ static HOST_WIDE_INT last_alias_set;
+
+ if (flag_strict_aliasing)
+ return ++last_alias_set;
+ else
+ return 0;
+}
/* Indicate that things in SUBSET can alias things in SUPERSET, but
not vice versa. For example, in C, a store to an `int' can alias a
structure containing an `int', but not vice versa. Here, the
structure would be the SUPERSET and `int' the SUBSET. This
- function should be called only once per SUPERSET/SUBSET pair. At
- present any given alias set may only be a subset of one superset.
+ function should be called only once per SUPERSET/SUBSET pair.
It is illegal for SUPERSET to be zero; everything is implicitly a
subset of alias set zero. */
void
record_alias_subset (superset, subset)
- int superset;
- int subset;
+ HOST_WIDE_INT superset;
+ HOST_WIDE_INT subset;
{
alias_set_entry superset_entry;
alias_set_entry subset_entry;
superset_entry->alias_set = superset;
superset_entry->children
= splay_tree_new (splay_tree_compare_ints, 0, 0);
+ superset_entry->has_zero_child = 0;
splay_tree_insert (alias_sets, (splay_tree_key) superset,
(splay_tree_value) superset_entry);
+ }
+ if (subset == 0)
+ superset_entry->has_zero_child = 1;
+ else
+ {
+ subset_entry = get_alias_set_entry (subset);
+ /* If there is an entry for the subset, enter all of its children
+ (if they are not already present) as children of the SUPERSET. */
+ if (subset_entry)
+ {
+ if (subset_entry->has_zero_child)
+ superset_entry->has_zero_child = 1;
+
+ splay_tree_foreach (subset_entry->children, insert_subset_children,
+ superset_entry->children);
+ }
+
+ /* Enter the SUBSET itself as a child of the SUPERSET. */
+ splay_tree_insert (superset_entry->children,
+ (splay_tree_key) subset, 0);
}
+}
+
+/* Record that component types of TYPE, if any, are part of that type for
+ aliasing purposes. For record types, we only record component types
+ for fields that are marked addressable. For array types, we always
+ record the component types, so the front end should not call this
+ function if the individual component aren't addressable. */
+
+void
+record_component_aliases (type)
+ tree type;
+{
+ HOST_WIDE_INT superset = get_alias_set (type);
+ tree field;
+
+ if (superset == 0)
+ return;
- subset_entry = get_alias_set_entry (subset);
+ switch (TREE_CODE (type))
+ {
+ case ARRAY_TYPE:
+ if (! TYPE_NONALIASED_COMPONENT (type))
+ record_alias_subset (superset, get_alias_set (TREE_TYPE (type)));
+ break;
- /* If there is an entry for the subset, enter all of its children
- (if they are not already present) as children of the SUPERSET. */
- if (subset_entry)
- splay_tree_foreach (subset_entry->children,
- insert_subset_children,
- superset_entry->children);
+ case RECORD_TYPE:
+ case UNION_TYPE:
+ case QUAL_UNION_TYPE:
+ for (field = TYPE_FIELDS (type); field != 0; field = TREE_CHAIN (field))
+ if (TREE_CODE (field) == FIELD_DECL && ! DECL_NONADDRESSABLE_P (field))
+ record_alias_subset (superset, get_alias_set (TREE_TYPE (field)));
+ break;
- /* Enter the SUBSET itself as a child of the SUPERSET. */
- splay_tree_insert (superset_entry->children,
- (splay_tree_key) subset, 0);
+ default:
+ break;
+ }
+}
+
+/* Allocate an alias set for use in storing and reading from the varargs
+ spill area. */
+
+HOST_WIDE_INT
+get_varargs_alias_set ()
+{
+ static HOST_WIDE_INT set = -1;
+
+ if (set == -1)
+ set = new_alias_set ();
+
+ return set;
+}
+
+/* Likewise, but used for the fixed portions of the frame, e.g., register
+ save areas. */
+
+HOST_WIDE_INT
+get_frame_alias_set ()
+{
+ static HOST_WIDE_INT set = -1;
+
+ if (set == -1)
+ set = new_alias_set ();
+
+ return set;
}
/* Inside SRC, the source of a SET, find a base address. */
reg_seen[regno] = 1;
}
-/* Called from loop optimization when a new pseudo-register is created. */
+/* Called from loop optimization when a new pseudo-register is
+ created. It indicates that REGNO is being set to VAL. f INVARIANT
+ is true then this value also describes an invariant relationship
+ which can be used to deduce that two registers with unknown values
+ are different. */
void
record_base_value (regno, val, invariant)
- int regno;
+ unsigned int regno;
rtx val;
int invariant;
{
- if ((unsigned) regno >= reg_base_value_size)
+ if (regno >= reg_base_value_size)
return;
- /* If INVARIANT is true then this value also describes an invariant
- relationship which can be used to deduce that two registers with
- unknown values are different. */
if (invariant && alias_invariant)
alias_invariant[regno] = val;
if (GET_CODE (val) == REG)
{
- if ((unsigned) REGNO (val) < reg_base_value_size)
+ if (REGNO (val) < reg_base_value_size)
reg_base_value[regno] = reg_base_value[REGNO (val)];
return;
reg_base_value[regno] = find_base_value (val);
}
-static rtx
+/* Returns a canonical version of X, from the point of view alias
+ analysis. (For example, if X is a MEM whose address is a register,
+ and the register has a known value (say a SYMBOL_REF), then a MEM
+ whose address is the SYMBOL_REF is returned.) */
+
+rtx
canon_rtx (x)
rtx x;
{
{
rtx new = gen_rtx_MEM (GET_MODE (x), addr);
- RTX_UNCHANGING_P (new) = RTX_UNCHANGING_P (x);
MEM_COPY_ATTRIBUTES (new, x);
- MEM_ALIAS_SET (new) = MEM_ALIAS_SET (x);
x = new;
}
}
if (GET_MODE (x) != GET_MODE (y))
return 0;
- /* REG, LABEL_REF, and SYMBOL_REF can be compared nonrecursively. */
-
- if (code == REG)
- return REGNO (x) == REGNO (y);
- if (code == LABEL_REF)
- return XEXP (x, 0) == XEXP (y, 0);
- if (code == SYMBOL_REF)
- return XSTR (x, 0) == XSTR (y, 0);
- if (code == CONST_INT)
- return INTVAL (x) == INTVAL (y);
- /* There's no need to compare the contents of CONST_DOUBLEs because
- they're unique. */
- if (code == CONST_DOUBLE)
- return 0;
- if (code == ADDRESSOF)
- return (REGNO (XEXP (x, 0)) == REGNO (XEXP (y, 0))
- && XINT (x, 1) == XINT (y, 1));
+ /* Some RTL can be compared without a recursive examination. */
+ switch (code)
+ {
+ case REG:
+ return REGNO (x) == REGNO (y);
+
+ case LABEL_REF:
+ return XEXP (x, 0) == XEXP (y, 0);
+
+ case SYMBOL_REF:
+ return XSTR (x, 0) == XSTR (y, 0);
+
+ case CONST_INT:
+ case CONST_DOUBLE:
+ /* There's no need to compare the contents of CONST_DOUBLEs or
+ CONST_INTs because pointer equality is a good enough
+ comparison for these nodes. */
+ return 0;
+
+ case ADDRESSOF:
+ return (REGNO (XEXP (x, 0)) == REGNO (XEXP (y, 0))
+ && XINT (x, 1) == XINT (y, 1));
+
+ 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. */
find_base_term (x)
register rtx x;
{
+ cselib_val *val;
+ struct elt_loc_list *l;
+
switch (GET_CODE (x))
{
case REG:
case POST_DEC:
return find_base_term (XEXP (x, 0));
+ case VALUE:
+ val = CSELIB_VAL_PTR (x);
+ for (l = val->locs; l; l = l->next)
+ if ((x = find_base_term (l->loc)) != 0)
+ return x;
+ return 0;
+
case CONST:
x = XEXP (x, 0);
if (GET_CODE (x) != PLUS && GET_CODE (x) != MINUS)
return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode);
}
+/* Convert the address X into something we can use. This is done by returning
+ it unchanged unless it is a value; in the latter case we call cselib to get
+ a more useful rtx. */
+
+static rtx
+get_addr (x)
+ rtx x;
+{
+ cselib_val *v;
+ struct elt_loc_list *l;
+
+ if (GET_CODE (x) != VALUE)
+ return x;
+ v = CSELIB_VAL_PTR (x);
+ for (l = v->locs; l; l = l->next)
+ if (CONSTANT_P (l->loc))
+ return l->loc;
+ for (l = v->locs; l; l = l->next)
+ if (GET_CODE (l->loc) != REG && GET_CODE (l->loc) != MEM)
+ return l->loc;
+ if (v->locs)
+ return v->locs->loc;
+ return x;
+}
+
/* Return the address of the (N_REFS + 1)th memory reference to ADDR
where SIZE is the size in bytes of the memory reference. If ADDR
is not modified by the memory reference then ADDR is returned. */
Nice to notice that varying addresses cannot conflict with fp if no
local variables had their addresses taken, but that's too hard now. */
-
static int
memrefs_conflict_p (xsize, x, ysize, y, c)
register rtx x, y;
int xsize, ysize;
HOST_WIDE_INT c;
{
+ if (GET_CODE (x) == VALUE)
+ x = get_addr (x);
+ if (GET_CODE (y) == VALUE)
+ y = get_addr (y);
if (GET_CODE (x) == HIGH)
x = XEXP (x, 0);
else if (GET_CODE (x) == LO_SUM)
changed. A volatile and non-volatile reference can be interchanged
though.
- A MEM_IN_STRUCT reference at a non-QImode non-AND varying address can never
- conflict with a non-MEM_IN_STRUCT reference at a fixed address. We must
- allow QImode aliasing because the ANSI C standard allows character
- pointers to alias anything. We are assuming that characters are
- always QImode here. We also must allow AND addresses, because they may
- generate accesses outside the object being referenced. This is used to
- generate aligned addresses from unaligned addresses, for instance, the
- alpha storeqi_unaligned pattern. */
+ A MEM_IN_STRUCT reference at a non-AND varying address can never
+ conflict with a non-MEM_IN_STRUCT reference at a fixed address. We
+ also must allow AND addresses, because they may generate accesses
+ outside the object being referenced. This is used to generate
+ aligned addresses from unaligned addresses, for instance, the alpha
+ storeqi_unaligned pattern. */
/* Read dependence: X is read after read in MEM takes place. There can
only be a dependence here if both reads are volatile. */
MEM2 if vice versa. Otherwise, returns NULL_RTX. If a non-NULL
value is returned MEM1 and MEM2 can never alias. VARIES_P is used
to decide whether or not an address may vary; it should return
- nozero whenever variation is possible. */
-
+ 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, varies_p)
- rtx mem1;
- rtx mem2;
+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));
-{
- rtx mem1_addr = XEXP (mem1, 0);
- rtx mem2_addr = XEXP (mem2, 0);
-
+{
if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2)
&& !varies_p (mem1_addr) && varies_p (mem2_addr))
/* MEM1 is a scalar at a fixed address; MEM2 is a struct at a
aliases_everything_p (mem)
rtx mem;
{
- if (GET_MODE (mem) == QImode)
- /* ANSI C says that a `char*' can point to anything. */
- return 1;
-
if (GET_CODE (XEXP (mem, 0)) == AND)
/* If the address is an AND, its very hard to know at what it is
actually pointing. */
if (mem_mode == VOIDmode)
mem_mode = GET_MODE (mem);
- if (! base_alias_check (XEXP (x, 0), XEXP (mem, 0), GET_MODE (x), mem_mode))
+ x_addr = get_addr (XEXP (x, 0));
+ mem_addr = get_addr (XEXP (mem, 0));
+
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
return 0;
- x_addr = canon_rtx (XEXP (x, 0));
- mem_addr = canon_rtx (XEXP (mem, 0));
+ x_addr = canon_rtx (x_addr);
+ mem_addr = canon_rtx (mem_addr);
if (! memrefs_conflict_p (GET_MODE_SIZE (mem_mode), mem_addr,
SIZE_FOR_MODE (x), x_addr, 0))
if (mem_mode == BLKmode || GET_MODE (x) == BLKmode)
return 1;
- return !fixed_scalar_and_varying_struct_p (mem, x, varies);
+ return ! fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
+ varies);
}
/* Returns non-zero if a write to X might alias a previous read from
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
+ if (DIFFERENT_ALIAS_SETS_P (x, mem))
+ return 0;
+
/* If MEM is an unchanging read, then it can't possibly conflict with
the store to X, because there is at most one store to MEM, and it must
have occurred somewhere before MEM. */
if (!writep && RTX_UNCHANGING_P (mem))
return 0;
- if (! base_alias_check (XEXP (x, 0), XEXP (mem, 0), GET_MODE (x),
- GET_MODE (mem)))
- return 0;
+ x_addr = get_addr (XEXP (x, 0));
+ mem_addr = get_addr (XEXP (mem, 0));
- x = canon_rtx (x);
- mem = canon_rtx (mem);
-
- if (DIFFERENT_ALIAS_SETS_P (x, mem))
+ if (! base_alias_check (x_addr, mem_addr, GET_MODE (x),
+ GET_MODE (mem)))
return 0;
- x_addr = XEXP (x, 0);
- mem_addr = XEXP (mem, 0);
+ x_addr = canon_rtx (x_addr);
+ mem_addr = canon_rtx (mem_addr);
if (!memrefs_conflict_p (SIZE_FOR_MODE (mem), mem_addr,
SIZE_FOR_MODE (x), x_addr, 0))
return 0;
fixed_scalar
- = fixed_scalar_and_varying_struct_p (mem, x, rtx_addr_varies_p);
-
+ = fixed_scalar_and_varying_struct_p (mem, x, mem_addr, x_addr,
+ rtx_addr_varies_p);
+
return (!(fixed_scalar == mem && !aliases_everything_p (x))
&& !(fixed_scalar == x && !aliases_everything_p (mem)));
}
if (GET_RTX_CLASS (code) == 'i')
{
- /* Constant functions are constant. */
+ /* 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_CALL_P (x))
- return 0;
- x = PATTERN (x);
+ {
+ x = CALL_INSN_FUNCTION_USAGE (x);
+ if (x == 0)
+ return 0;
+ }
+ else
+ x = PATTERN (x);
code = GET_CODE (x);
}
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
- if (fmt[i] == 'e')
+ if (fmt[i] == 'e' && XEXP (x, i))
{
if (nonlocal_reference_p (XEXP (x, i)))
return 1;
alias_sets = splay_tree_new (splay_tree_compare_ints, 0, 0);
}
+/* Initialize the aliasing machinery. Initialize the REG_KNOWN_VALUE
+ array. */
+
void
init_alias_analysis ()
{
/* Walk the insns adding values to the new_reg_base_value array. */
for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
{
-#if defined (HAVE_prologue) || defined (HAVE_epilogue)
- if (prologue_epilogue_contains (insn))
- continue;
-#endif
if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
{
rtx note, set;
+
+#if defined (HAVE_prologue) || defined (HAVE_epilogue)
+ if (prologue_epilogue_contains (insn))
+ continue;
+#endif
+
/* If this insn has a noalias note, process it, Otherwise,
scan for sets. A simple set will have no side effects
which could change the base value of any other register. */
if (GET_CODE (PATTERN (insn)) == SET
- && (find_reg_note (insn, REG_NOALIAS, NULL_RTX)))
+ && REG_NOTES (insn) != 0
+ && find_reg_note (insn, REG_NOALIAS, NULL_RTX))
record_set (SET_DEST (PATTERN (insn)), NULL_RTX, NULL);
else
note_stores (PATTERN (insn), record_set, NULL);
if (set != 0
&& GET_CODE (SET_DEST (set)) == REG
&& REGNO (SET_DEST (set)) >= FIRST_PSEUDO_REGISTER
+ && REG_NOTES (insn) != 0
&& (((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
&& REG_N_SETS (REGNO (SET_DEST (set))) == 1)
|| (note = find_reg_note (insn, REG_EQUIV, NULL_RTX)) != 0)
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