/* The aliasing API provided here solves related but different problems:
- Say there exists (in c)
+ Say there exists (in c)
struct X {
struct Y y1;
this may be too conservative for some C++ types.
The pass ipa-type-escape does this analysis for the types whose
- instances do not escape across the compilation boundary.
+ instances do not escape across the compilation boundary.
Historically in GCC, these two problems were combined and a single
data structure was used to represent the solution to these
`double'. (However, a store to an `int' cannot alias a `double'
and vice versa.) We indicate this via a tree structure that looks
like:
- struct S
- / \
+ struct S
+ / \
/ \
- |/_ _\|
- int double
+ |/_ _\|
+ int double
(The arrows are directed and point downwards.)
In this situation we say the alias set for `struct S' is the
current function performs nonlocal memory memory references for the
purposes of marking the function as a constant function. */
-static GTY(()) varray_type reg_base_value;
+static GTY(()) VEC(rtx,gc) *reg_base_value;
static rtx *new_reg_base_value;
/* We preserve the copy of old array around to avoid amount of garbage
produced. About 8% of garbage produced were attributed to this
array. */
-static GTY((deletable)) varray_type old_reg_base_value;
+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 REG_BASE_VALUE(X) \
- (reg_base_value && REGNO (X) < VARRAY_SIZE (reg_base_value) \
- ? VARRAY_RTX (reg_base_value, REGNO (X)) : 0)
+#define REG_BASE_VALUE(X) \
+ (REGNO (X) < VEC_length (rtx, reg_base_value) \
+ ? VEC_index (rtx, reg_base_value, REGNO (X)) : 0)
/* Vector indexed by N giving the initial (unchanging) value known for
pseudo-register N. This array is initialized in init_alias_analysis,
NOTE_INSN_FUNCTION_BEG note. */
static bool copying_arguments;
+DEF_VEC_P(alias_set_entry);
+DEF_VEC_ALLOC_P(alias_set_entry,gc);
+
/* The splay-tree used to store the various alias set entries. */
-static GTY ((param_is (struct alias_set_entry))) varray_type alias_sets;
+static GTY (()) VEC(alias_set_entry,gc) *alias_sets;
\f
/* Returns a pointer to the alias set entry for ALIAS_SET, if there is
such an entry, or NULL otherwise. */
static inline alias_set_entry
get_alias_set_entry (HOST_WIDE_INT alias_set)
{
- return (alias_set_entry)VARRAY_GENERIC_PTR (alias_sets, alias_set);
+ return VEC_index (alias_set_entry, alias_sets, alias_set);
}
/* Returns nonzero if the alias sets for MEM1 and MEM2 are such that
return 0;
}
+/* Return true if the first alias set is a subset of the second. */
+
+bool
+alias_set_subset_of (HOST_WIDE_INT set1, HOST_WIDE_INT set2)
+{
+ alias_set_entry ase;
+
+ /* Everything is a subset of the "aliases everything" set. */
+ if (set2 == 0)
+ return true;
+
+ /* Otherwise, check if set1 is a subset of set2. */
+ ase = get_alias_set_entry (set2);
+ if (ase != 0
+ && (splay_tree_lookup (ase->children,
+ (splay_tree_key) set1)))
+ return true;
+ return false;
+}
+
/* Return 1 if the two specified alias sets may conflict. */
int
/* Return a brand-new alias set. */
-static GTY(()) HOST_WIDE_INT last_alias_set;
-
HOST_WIDE_INT
new_alias_set (void)
{
if (flag_strict_aliasing)
{
- if (!alias_sets)
- VARRAY_GENERIC_PTR_INIT (alias_sets, 10, "alias sets");
- else
- VARRAY_GROW (alias_sets, last_alias_set + 2);
- return ++last_alias_set;
+ if (alias_sets == 0)
+ VEC_safe_push (alias_set_entry, gc, alias_sets, 0);
+ VEC_safe_push (alias_set_entry, gc, alias_sets, 0);
+ return VEC_length (alias_set_entry, alias_sets) - 1;
}
else
return 0;
superset_entry->children
= splay_tree_new_ggc (splay_tree_compare_ints);
superset_entry->has_zero_child = 0;
- VARRAY_GENERIC_PTR (alias_sets, superset) = superset_entry;
+ VEC_replace (alias_set_entry, alias_sets, superset, superset_entry);
}
if (subset == 0)
{
int i;
tree binfo, base_binfo;
-
+
for (binfo = TYPE_BINFO (type), i = 0;
BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
record_alias_subset (superset,
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 || fixed_regs[regno])
- && regno < VARRAY_SIZE (reg_base_value))
+ && regno < VEC_length (rtx, reg_base_value))
{
/* If we're inside init_alias_analysis, use new_reg_base_value
to reduce the number of relaxation iterations. */
&& REG_N_SETS (regno) == 1)
return new_reg_base_value[regno];
- if (VARRAY_RTX (reg_base_value, regno))
- return VARRAY_RTX (reg_base_value, regno);
+ if (VEC_index (rtx, reg_base_value, regno))
+ return VEC_index (rtx, reg_base_value, regno);
}
return 0;
regno = REGNO (dest);
- gcc_assert (regno < VARRAY_SIZE (reg_base_value));
+ gcc_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. */
If neither case holds, reject the original base value as invalid.
Note that the following situation is not detected:
- extern int x, y; int *p = &x; p += (&y-&x);
+ extern int x, y; int *p = &x; p += (&y-&x);
ANSI C does not allow computing the difference of addresses
of distinct top level objects. */
/* If a value is known for REGNO, return it. */
-rtx
+rtx
get_reg_known_value (unsigned int regno)
{
if (regno >= FIRST_PSEUDO_REGISTER)
if (offset)
addr = gen_rtx_PLUS (GET_MODE (addr), XEXP (addr, 0),
- GEN_INT (offset));
+ GEN_INT (offset));
else
addr = XEXP (addr, 0);
addr = canon_rtx (addr);
if (! flag_strict_aliasing)
return NULL_RTX;
- if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2)
+ 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_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2)
+ 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. */
/* 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 fieldcontext = DECL_FIELD_CONTEXT (field);
if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
TREE_TYPE (field)))
- return 1;
+ return 1;
}
{
tree t = decl_for_component_ref (exprx);
tree fieldcontext = DECL_FIELD_CONTEXT (field);
if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
TREE_TYPE (field)))
- return 1;
+ return 1;
}
{
tree t = decl_for_component_ref (expry);
return 1;
/* (mem:BLK (scratch)) is a special mechanism to conflict with everything.
- This is used in epilogue deallocation functions. */
+ This is used in epilogue deallocation functions, and in cselib. */
if (GET_MODE (x) == BLKmode && GET_CODE (XEXP (x, 0)) == SCRATCH)
return 1;
if (GET_MODE (mem) == BLKmode && GET_CODE (XEXP (mem, 0)) == SCRATCH)
reg_known_value = ggc_calloc (reg_known_value_size, sizeof (rtx));
reg_known_equiv_p = xcalloc (reg_known_value_size, sizeof (bool));
- /* Overallocate reg_base_value to allow some growth during loop
- optimization. Loop unrolling can create a large number of
- registers. */
+ /* If we have memory allocated from the previous run, use it. */
if (old_reg_base_value)
- {
- reg_base_value = old_reg_base_value;
- /* If varray gets large zeroing cost may get important. */
- if (VARRAY_SIZE (reg_base_value) > 256
- && VARRAY_SIZE (reg_base_value) > 4 * maxreg)
- VARRAY_GROW (reg_base_value, maxreg);
- VARRAY_CLEAR (reg_base_value);
- if (VARRAY_SIZE (reg_base_value) < maxreg)
- VARRAY_GROW (reg_base_value, maxreg);
- }
- else
- {
- VARRAY_RTX_INIT (reg_base_value, maxreg, "reg_base_value");
- }
+ reg_base_value = old_reg_base_value;
+
+ if (reg_base_value)
+ VEC_truncate (rtx, reg_base_value, 0);
+
+ VEC_safe_grow (rtx, gc, reg_base_value, maxreg);
+ memset (VEC_address (rtx, reg_base_value), 0,
+ sizeof (rtx) * VEC_length (rtx, reg_base_value));
new_reg_base_value = XNEWVEC (rtx, maxreg);
reg_seen = XNEWVEC (char, maxreg);
#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. */
+ 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
&& REG_NOTES (insn) != 0
/* Now propagate values from new_reg_base_value to reg_base_value. */
gcc_assert (maxreg == (unsigned int) max_reg_num());
-
+
for (ui = 0; ui < maxreg; ui++)
{
if (new_reg_base_value[ui]
- && new_reg_base_value[ui] != VARRAY_RTX (reg_base_value, ui)
+ && new_reg_base_value[ui] != VEC_index (rtx, reg_base_value, ui)
&& ! rtx_equal_p (new_reg_base_value[ui],
- VARRAY_RTX (reg_base_value, ui)))
+ VEC_index (rtx, reg_base_value, ui)))
{
- VARRAY_RTX (reg_base_value, ui) = new_reg_base_value[ui];
+ VEC_replace (rtx, reg_base_value, ui, new_reg_base_value[ui]);
changed = 1;
}
}
if (reg_known_value[i] == 0)
reg_known_value[i] = regno_reg_rtx[i + FIRST_PSEUDO_REGISTER];
- /* Simplify the reg_base_value array so that no register refers to
- another register, except to special registers indirectly through
- ADDRESS expressions.
-
- In theory this loop can take as long as O(registers^2), but unless
- there are very long dependency chains it will run in close to linear
- time.
-
- This loop may not be needed any longer now that the main loop does
- a better job at propagating alias information. */
- pass = 0;
- do
- {
- changed = 0;
- pass++;
- for (ui = 0; ui < maxreg; ui++)
- {
- rtx base = VARRAY_RTX (reg_base_value, ui);
- if (base && REG_P (base))
- {
- unsigned int base_regno = REGNO (base);
- if (base_regno == ui) /* register set from itself */
- VARRAY_RTX (reg_base_value, ui) = 0;
- else
- VARRAY_RTX (reg_base_value, ui)
- = VARRAY_RTX (reg_base_value, base_regno);
- changed = 1;
- }
- }
- }
- while (changed && pass < MAX_ALIAS_LOOP_PASSES);
-
/* Clean up. */
free (new_reg_base_value);
new_reg_base_value = 0;
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