VARYING
} ccp_lattice_t;
+struct prop_value_d {
+ /* Lattice value. */
+ ccp_lattice_t lattice_val;
+
+ /* Propagated value. */
+ tree value;
+
+ /* Mask that applies to the propagated value during CCP. For
+ X with a CONSTANT lattice value X & ~mask == value & ~mask. */
+ double_int mask;
+};
+
+typedef struct prop_value_d prop_value_t;
+
/* Array of propagated constant values. After propagation,
CONST_VAL[I].VALUE holds the constant value for SSA_NAME(I). If
the constant is held in an SSA name representing a memory store
static void canonicalize_float_value (prop_value_t *);
static bool ccp_fold_stmt (gimple_stmt_iterator *);
+static tree fold_ctor_reference (tree type, tree ctor,
+ unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size);
/* Dump constant propagation value VAL to file OUTF prefixed by PREFIX. */
break;
case CONSTANT:
fprintf (outf, "%sCONSTANT ", prefix);
- print_generic_expr (outf, val.value, dump_flags);
+ if (TREE_CODE (val.value) != INTEGER_CST
+ || double_int_zero_p (val.mask))
+ print_generic_expr (outf, val.value, dump_flags);
+ else
+ {
+ double_int cval = double_int_and_not (tree_to_double_int (val.value),
+ val.mask);
+ fprintf (outf, "%sCONSTANT " HOST_WIDE_INT_PRINT_DOUBLE_HEX,
+ prefix, cval.high, cval.low);
+ fprintf (outf, " (" HOST_WIDE_INT_PRINT_DOUBLE_HEX ")",
+ val.mask.high, val.mask.low);
+ }
break;
default:
gcc_unreachable ();
get_default_value (tree var)
{
tree sym = SSA_NAME_VAR (var);
- prop_value_t val = { UNINITIALIZED, NULL_TREE };
+ prop_value_t val = { UNINITIALIZED, NULL_TREE, { 0, 0 } };
gimple stmt;
stmt = SSA_NAME_DEF_STMT (var);
&& TREE_CODE (sym) == VAR_DECL)
val.lattice_val = UNDEFINED;
else
- val.lattice_val = VARYING;
+ {
+ val.lattice_val = VARYING;
+ val.mask = double_int_minus_one;
+ }
}
else if (is_gimple_assign (stmt)
/* Value-returning GIMPLE_CALL statements assign to
{
/* Otherwise, VAR will never take on a constant value. */
val.lattice_val = VARYING;
+ val.mask = double_int_minus_one;
}
return val;
static inline tree
get_constant_value (tree var)
{
- prop_value_t *val = get_value (var);
- if (val && val->lattice_val == CONSTANT)
+ prop_value_t *val;
+ if (TREE_CODE (var) != SSA_NAME)
+ {
+ if (is_gimple_min_invariant (var))
+ return var;
+ return NULL_TREE;
+ }
+ val = get_value (var);
+ if (val
+ && val->lattice_val == CONSTANT
+ && (TREE_CODE (val->value) != INTEGER_CST
+ || double_int_zero_p (val->mask)))
return val->value;
return NULL_TREE;
}
val->lattice_val = VARYING;
val->value = NULL_TREE;
+ val->mask = double_int_minus_one;
}
/* For float types, modify the value of VAL to make ccp work correctly
}
}
+/* Return whether the lattice transition is valid. */
+
+static bool
+valid_lattice_transition (prop_value_t old_val, prop_value_t new_val)
+{
+ /* Lattice transitions must always be monotonically increasing in
+ value. */
+ if (old_val.lattice_val < new_val.lattice_val)
+ return true;
+
+ if (old_val.lattice_val != new_val.lattice_val)
+ return false;
+
+ if (!old_val.value && !new_val.value)
+ return true;
+
+ /* Now both lattice values are CONSTANT. */
+
+ /* Allow transitioning from &x to &x & ~3. */
+ if (TREE_CODE (old_val.value) != INTEGER_CST
+ && TREE_CODE (new_val.value) == INTEGER_CST)
+ return true;
+
+ /* Bit-lattices have to agree in the still valid bits. */
+ if (TREE_CODE (old_val.value) == INTEGER_CST
+ && TREE_CODE (new_val.value) == INTEGER_CST)
+ return double_int_equal_p
+ (double_int_and_not (tree_to_double_int (old_val.value),
+ new_val.mask),
+ double_int_and_not (tree_to_double_int (new_val.value),
+ new_val.mask));
+
+ /* Otherwise constant values have to agree. */
+ return operand_equal_p (old_val.value, new_val.value, 0);
+}
+
/* Set the value for variable VAR to NEW_VAL. Return true if the new
value is different from VAR's previous value. */
canonicalize_float_value (&new_val);
- /* Lattice transitions must always be monotonically increasing in
- value. If *OLD_VAL and NEW_VAL are the same, return false to
- inform the caller that this was a non-transition. */
+ /* We have to be careful to not go up the bitwise lattice
+ represented by the mask.
+ ??? This doesn't seem to be the best place to enforce this. */
+ if (new_val.lattice_val == CONSTANT
+ && old_val->lattice_val == CONSTANT
+ && TREE_CODE (new_val.value) == INTEGER_CST
+ && TREE_CODE (old_val->value) == INTEGER_CST)
+ {
+ double_int diff;
+ diff = double_int_xor (tree_to_double_int (new_val.value),
+ tree_to_double_int (old_val->value));
+ new_val.mask = double_int_ior (new_val.mask,
+ double_int_ior (old_val->mask, diff));
+ }
- gcc_assert (old_val->lattice_val < new_val.lattice_val
- || (old_val->lattice_val == new_val.lattice_val
- && ((!old_val->value && !new_val.value)
- || operand_equal_p (old_val->value, new_val.value, 0))));
+ gcc_assert (valid_lattice_transition (*old_val, new_val));
- if (old_val->lattice_val != new_val.lattice_val)
+ /* If *OLD_VAL and NEW_VAL are the same, return false to inform the
+ caller that this was a non-transition. */
+ if (old_val->lattice_val != new_val.lattice_val
+ || (new_val.lattice_val == CONSTANT
+ && TREE_CODE (new_val.value) == INTEGER_CST
+ && (TREE_CODE (old_val->value) != INTEGER_CST
+ || !double_int_equal_p (new_val.mask, old_val->mask))))
{
+ /* ??? We would like to delay creation of INTEGER_CSTs from
+ partially constants here. */
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
dump_lattice_value (dump_file, "Lattice value changed to ", new_val);
return false;
}
-/* Return the value for the tree operand EXPR. */
+static prop_value_t get_value_for_expr (tree, bool);
+static prop_value_t bit_value_binop (enum tree_code, tree, tree, tree);
+static void bit_value_binop_1 (enum tree_code, tree, double_int *, double_int *,
+ tree, double_int, double_int,
+ tree, double_int, double_int);
+
+/* Return a double_int that can be used for bitwise simplifications
+ from VAL. */
+
+static double_int
+value_to_double_int (prop_value_t val)
+{
+ if (val.value
+ && TREE_CODE (val.value) == INTEGER_CST)
+ return tree_to_double_int (val.value);
+ else
+ return double_int_zero;
+}
+
+/* Return the value for the address expression EXPR based on alignment
+ information. */
+
+static prop_value_t
+get_value_from_alignment (tree expr)
+{
+ prop_value_t val;
+ HOST_WIDE_INT bitsize, bitpos;
+ tree base, offset;
+ enum machine_mode mode;
+ int align;
+
+ gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
+
+ base = get_inner_reference (TREE_OPERAND (expr, 0),
+ &bitsize, &bitpos, &offset,
+ &mode, &align, &align, false);
+ if (TREE_CODE (base) == MEM_REF)
+ val = bit_value_binop (PLUS_EXPR, TREE_TYPE (expr),
+ TREE_OPERAND (base, 0), TREE_OPERAND (base, 1));
+ else if (base
+ && ((align = get_object_alignment (base, BIGGEST_ALIGNMENT))
+ > BITS_PER_UNIT))
+ {
+ val.lattice_val = CONSTANT;
+ /* We assume pointers are zero-extended. */
+ val.mask = double_int_and_not
+ (double_int_mask (TYPE_PRECISION (TREE_TYPE (expr))),
+ uhwi_to_double_int (align / BITS_PER_UNIT - 1));
+ val.value = build_int_cst (TREE_TYPE (expr), 0);
+ }
+ else
+ {
+ val.lattice_val = VARYING;
+ val.mask = double_int_minus_one;
+ val.value = NULL_TREE;
+ }
+ if (bitpos != 0)
+ {
+ double_int value, mask;
+ bit_value_binop_1 (PLUS_EXPR, TREE_TYPE (expr), &value, &mask,
+ TREE_TYPE (expr), value_to_double_int (val), val.mask,
+ TREE_TYPE (expr),
+ shwi_to_double_int (bitpos / BITS_PER_UNIT),
+ double_int_zero);
+ val.lattice_val = double_int_minus_one_p (mask) ? VARYING : CONSTANT;
+ val.mask = mask;
+ if (val.lattice_val == CONSTANT)
+ val.value = double_int_to_tree (TREE_TYPE (expr), value);
+ else
+ val.value = NULL_TREE;
+ }
+ /* ??? We should handle i * 4 and more complex expressions from
+ the offset, possibly by just expanding get_value_for_expr. */
+ if (offset != NULL_TREE)
+ {
+ double_int value, mask;
+ prop_value_t oval = get_value_for_expr (offset, true);
+ bit_value_binop_1 (PLUS_EXPR, TREE_TYPE (expr), &value, &mask,
+ TREE_TYPE (expr), value_to_double_int (val), val.mask,
+ TREE_TYPE (expr), value_to_double_int (oval),
+ oval.mask);
+ val.mask = mask;
+ if (double_int_minus_one_p (mask))
+ {
+ val.lattice_val = VARYING;
+ val.value = NULL_TREE;
+ }
+ else
+ {
+ val.lattice_val = CONSTANT;
+ val.value = double_int_to_tree (TREE_TYPE (expr), value);
+ }
+ }
+
+ return val;
+}
+
+/* Return the value for the tree operand EXPR. If FOR_BITS_P is true
+ return constant bits extracted from alignment information for
+ invariant addresses. */
static prop_value_t
-get_value_for_expr (tree expr)
+get_value_for_expr (tree expr, bool for_bits_p)
{
prop_value_t val;
if (TREE_CODE (expr) == SSA_NAME)
- val = *(get_value (expr));
- else if (is_gimple_min_invariant (expr))
+ {
+ val = *get_value (expr);
+ if (for_bits_p
+ && val.lattice_val == CONSTANT
+ && TREE_CODE (val.value) == ADDR_EXPR)
+ val = get_value_from_alignment (val.value);
+ }
+ else if (is_gimple_min_invariant (expr)
+ && (!for_bits_p || TREE_CODE (expr) != ADDR_EXPR))
{
val.lattice_val = CONSTANT;
val.value = expr;
+ val.mask = double_int_zero;
canonicalize_float_value (&val);
}
+ else if (TREE_CODE (expr) == ADDR_EXPR)
+ val = get_value_from_alignment (expr);
else
{
val.lattice_val = VARYING;
+ val.mask = double_int_minus_one;
val.value = NULL_TREE;
}
-
return val;
}
-
/* Return the likely CCP lattice value for STMT.
If STMT has no operands, then return CONSTANT.
if (!dbg_cnt (ccp))
{
const_val[i].lattice_val = VARYING;
+ const_val[i].mask = double_int_minus_one;
const_val[i].value = NULL_TREE;
}
}
ccp_finalize (void)
{
bool something_changed;
+ unsigned i;
do_dbg_cnt ();
+
+ /* Derive alignment and misalignment information from partially
+ constant pointers in the lattice. */
+ for (i = 1; i < num_ssa_names; ++i)
+ {
+ tree name = ssa_name (i);
+ prop_value_t *val;
+ struct ptr_info_def *pi;
+ unsigned int tem, align;
+
+ if (!name
+ || !POINTER_TYPE_P (TREE_TYPE (name)))
+ continue;
+
+ val = get_value (name);
+ if (val->lattice_val != CONSTANT
+ || TREE_CODE (val->value) != INTEGER_CST)
+ continue;
+
+ /* Trailing constant bits specify the alignment, trailing value
+ bits the misalignment. */
+ tem = val->mask.low;
+ align = (tem & -tem);
+ if (align == 1)
+ continue;
+
+ pi = get_ptr_info (name);
+ pi->align = align;
+ pi->misalign = TREE_INT_CST_LOW (val->value) & (align - 1);
+ }
+
/* Perform substitutions based on the known constant values. */
- something_changed = substitute_and_fold (const_val, ccp_fold_stmt, true);
+ something_changed = substitute_and_fold (get_constant_value,
+ ccp_fold_stmt, true);
free (const_val);
const_val = NULL;
{
/* any M VARYING = VARYING. */
val1->lattice_val = VARYING;
+ val1->mask = double_int_minus_one;
val1->value = NULL_TREE;
}
else if (val1->lattice_val == CONSTANT
&& val2->lattice_val == CONSTANT
+ && TREE_CODE (val1->value) == INTEGER_CST
+ && TREE_CODE (val2->value) == INTEGER_CST)
+ {
+ /* Ci M Cj = Ci if (i == j)
+ Ci M Cj = VARYING if (i != j)
+
+ For INTEGER_CSTs mask unequal bits. If no equal bits remain,
+ drop to varying. */
+ val1->mask
+ = double_int_ior (double_int_ior (val1->mask,
+ val2->mask),
+ double_int_xor (tree_to_double_int (val1->value),
+ tree_to_double_int (val2->value)));
+ if (double_int_minus_one_p (val1->mask))
+ {
+ val1->lattice_val = VARYING;
+ val1->value = NULL_TREE;
+ }
+ }
+ else if (val1->lattice_val == CONSTANT
+ && val2->lattice_val == CONSTANT
&& simple_cst_equal (val1->value, val2->value) == 1)
{
/* Ci M Cj = Ci if (i == j)
Ci M Cj = VARYING if (i != j)
- If these two values come from memory stores, make sure that
- they come from the same memory reference.
- Nothing to do. VAL1 already contains the value we want. */
+ VAL1 already contains the value we want for equivalent values. */
+ }
+ else if (val1->lattice_val == CONSTANT
+ && val2->lattice_val == CONSTANT
+ && (TREE_CODE (val1->value) == ADDR_EXPR
+ || TREE_CODE (val2->value) == ADDR_EXPR))
+ {
+ /* When not equal addresses are involved try meeting for
+ alignment. */
+ prop_value_t tem = *val2;
+ if (TREE_CODE (val1->value) == ADDR_EXPR)
+ *val1 = get_value_for_expr (val1->value, true);
+ if (TREE_CODE (val2->value) == ADDR_EXPR)
+ tem = get_value_for_expr (val2->value, true);
+ ccp_lattice_meet (val1, &tem);
}
else
{
/* Any other combination is VARYING. */
val1->lattice_val = VARYING;
+ val1->mask = double_int_minus_one;
val1->value = NULL_TREE;
}
}
if (e->flags & EDGE_EXECUTABLE)
{
tree arg = gimple_phi_arg (phi, i)->def;
- prop_value_t arg_val = get_value_for_expr (arg);
+ prop_value_t arg_val = get_value_for_expr (arg, false);
ccp_lattice_meet (&new_val, &arg_val);
}
}
-/* Return the tree representing the element referenced by T if T is an
- ARRAY_REF or COMPONENT_REF into constant aggregates. Return
- NULL_TREE otherwise. */
+/* See if we can find constructor defining value of BASE.
+ When we know the consructor with constant offset (such as
+ base is array[40] and we do know constructor of array), then
+ BIT_OFFSET is adjusted accordingly.
-tree
-fold_const_aggregate_ref (tree t)
+ As a special case, return error_mark_node when constructor
+ is not explicitly available, but it is known to be zero
+ such as 'static const int a;'. */
+static tree
+get_base_constructor (tree base, HOST_WIDE_INT *bit_offset)
{
- tree base, ctor, idx, field;
- unsigned HOST_WIDE_INT cnt;
- tree cfield, cval;
- tree tem;
+ HOST_WIDE_INT bit_offset2, size, max_size;
+ if (TREE_CODE (base) == MEM_REF)
+ {
+ if (!integer_zerop (TREE_OPERAND (base, 1)))
+ {
+ if (!host_integerp (TREE_OPERAND (base, 1), 0))
+ return NULL_TREE;
+ *bit_offset += (mem_ref_offset (base).low
+ * BITS_PER_UNIT);
+ }
- if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
- return get_symbol_constant_value (t);
+ base = get_constant_value (TREE_OPERAND (base, 0));
+ if (!base || TREE_CODE (base) != ADDR_EXPR)
+ return NULL_TREE;
+ base = TREE_OPERAND (base, 0);
+ }
- switch (TREE_CODE (t))
+ /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its
+ DECL_INITIAL. If BASE is a nested reference into another
+ ARRAY_REF or COMPONENT_REF, make a recursive call to resolve
+ the inner reference. */
+ switch (TREE_CODE (base))
{
+ case VAR_DECL:
+ if (!const_value_known_p (base))
+ return NULL_TREE;
+
+ /* Fallthru. */
+ case CONST_DECL:
+ if (!DECL_INITIAL (base)
+ && (TREE_STATIC (base) || DECL_EXTERNAL (base)))
+ return error_mark_node;
+ return DECL_INITIAL (base);
+
case ARRAY_REF:
- /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its
- DECL_INITIAL. If BASE is a nested reference into another
- ARRAY_REF or COMPONENT_REF, make a recursive call to resolve
- the inner reference. */
- base = TREE_OPERAND (t, 0);
- switch (TREE_CODE (base))
- {
- case MEM_REF:
- /* ??? We could handle this case. */
- if (!integer_zerop (TREE_OPERAND (base, 1)))
- return NULL_TREE;
- base = get_base_address (base);
- if (!base
- || TREE_CODE (base) != VAR_DECL)
- return NULL_TREE;
+ case COMPONENT_REF:
+ base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size);
+ if (max_size == -1 || size != max_size)
+ return NULL_TREE;
+ *bit_offset += bit_offset2;
+ return get_base_constructor (base, bit_offset);
- /* Fallthru. */
- case VAR_DECL:
- if (!TREE_READONLY (base)
- || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE
- || !targetm.binds_local_p (base))
- return NULL_TREE;
+ case STRING_CST:
+ case CONSTRUCTOR:
+ return base;
- ctor = DECL_INITIAL (base);
- break;
+ default:
+ return NULL_TREE;
+ }
+}
- case ARRAY_REF:
- case COMPONENT_REF:
- ctor = fold_const_aggregate_ref (base);
- break;
+/* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE
+ to the memory at bit OFFSET.
- case STRING_CST:
- case CONSTRUCTOR:
- ctor = base;
- break;
+ We do only simple job of folding byte accesses. */
- default:
- return NULL_TREE;
- }
+static tree
+fold_string_cst_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size)
+{
+ if (INTEGRAL_TYPE_P (type)
+ && (TYPE_MODE (type)
+ == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
+ && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
+ == MODE_INT)
+ && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1
+ && size == BITS_PER_UNIT
+ && !(offset % BITS_PER_UNIT))
+ {
+ offset /= BITS_PER_UNIT;
+ if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor))
+ return build_int_cst_type (type, (TREE_STRING_POINTER (ctor)
+ [offset]));
+ /* Folding
+ const char a[20]="hello";
+ return a[10];
+
+ might lead to offset greater than string length. In this case we
+ know value is either initialized to 0 or out of bounds. Return 0
+ in both cases. */
+ return build_zero_cst (type);
+ }
+ return NULL_TREE;
+}
- if (ctor == NULL_TREE
- || (TREE_CODE (ctor) != CONSTRUCTOR
- && TREE_CODE (ctor) != STRING_CST)
- || !TREE_STATIC (ctor))
- return NULL_TREE;
+/* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size
+ SIZE to the memory at bit OFFSET. */
- /* Get the index. If we have an SSA_NAME, try to resolve it
- with the current lattice value for the SSA_NAME. */
- idx = TREE_OPERAND (t, 1);
- switch (TREE_CODE (idx))
- {
- case SSA_NAME:
- if ((tem = get_constant_value (idx))
- && TREE_CODE (tem) == INTEGER_CST)
- idx = tem;
- else
- return NULL_TREE;
- break;
+static tree
+fold_array_ctor_reference (tree type, tree ctor,
+ unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size)
+{
+ unsigned HOST_WIDE_INT cnt;
+ tree cfield, cval;
+ double_int low_bound, elt_size;
+ double_int index, max_index;
+ double_int access_index;
+ tree domain_type = TYPE_DOMAIN (TREE_TYPE (ctor));
+ HOST_WIDE_INT inner_offset;
+
+ /* Compute low bound and elt size. */
+ if (domain_type && TYPE_MIN_VALUE (domain_type))
+ {
+ /* Static constructors for variably sized objects makes no sense. */
+ gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST);
+ low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type));
+ }
+ else
+ low_bound = double_int_zero;
+ /* Static constructors for variably sized objects makes no sense. */
+ gcc_assert (TREE_CODE(TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor))))
+ == INTEGER_CST);
+ elt_size =
+ tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor))));
+
+
+ /* We can handle only constantly sized accesses that are known to not
+ be larger than size of array element. */
+ if (!TYPE_SIZE_UNIT (type)
+ || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
+ || double_int_cmp (elt_size,
+ tree_to_double_int (TYPE_SIZE_UNIT (type)), 0) < 0)
+ return NULL_TREE;
- case INTEGER_CST:
- break;
+ /* Compute the array index we look for. */
+ access_index = double_int_udiv (uhwi_to_double_int (offset / BITS_PER_UNIT),
+ elt_size, TRUNC_DIV_EXPR);
+ access_index = double_int_add (access_index, low_bound);
- default:
- return NULL_TREE;
- }
+ /* And offset within the access. */
+ inner_offset = offset % (double_int_to_uhwi (elt_size) * BITS_PER_UNIT);
+
+ /* See if the array field is large enough to span whole access. We do not
+ care to fold accesses spanning multiple array indexes. */
+ if (inner_offset + size > double_int_to_uhwi (elt_size) * BITS_PER_UNIT)
+ return NULL_TREE;
- /* Fold read from constant string. */
- if (TREE_CODE (ctor) == STRING_CST)
+ index = double_int_sub (low_bound, double_int_one);
+ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
+ {
+ /* Array constructor might explicitely set index, or specify range
+ or leave index NULL meaning that it is next index after previous
+ one. */
+ if (cfield)
{
- if ((TYPE_MODE (TREE_TYPE (t))
- == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
- && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
- == MODE_INT)
- && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1
- && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0)
- return build_int_cst_type (TREE_TYPE (t),
- (TREE_STRING_POINTER (ctor)
- [TREE_INT_CST_LOW (idx)]));
- return NULL_TREE;
+ if (TREE_CODE (cfield) == INTEGER_CST)
+ max_index = index = tree_to_double_int (cfield);
+ else
+ {
+ gcc_assert (TREE_CODE (cfield) == RANGE_EXPR);
+ index = tree_to_double_int (TREE_OPERAND (cfield, 0));
+ max_index = tree_to_double_int (TREE_OPERAND (cfield, 1));
+ }
}
+ else
+ max_index = index = double_int_add (index, double_int_one);
- /* Whoo-hoo! I'll fold ya baby. Yeah! */
- FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
- if (tree_int_cst_equal (cfield, idx))
- {
- STRIP_NOPS (cval);
- if (TREE_CODE (cval) == ADDR_EXPR)
- {
- tree base = get_base_address (TREE_OPERAND (cval, 0));
- if (base && TREE_CODE (base) == VAR_DECL)
- add_referenced_var (base);
- }
- return cval;
- }
- break;
+ /* Do we have match? */
+ if (double_int_cmp (access_index, index, 1) >= 0
+ && double_int_cmp (access_index, max_index, 1) <= 0)
+ return fold_ctor_reference (type, cval, inner_offset, size);
+ }
+ /* When memory is not explicitely mentioned in constructor,
+ it is 0 (or out of range). */
+ return build_zero_cst (type);
+}
- case COMPONENT_REF:
- /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its
- DECL_INITIAL. If BASE is a nested reference into another
- ARRAY_REF or COMPONENT_REF, make a recursive call to resolve
- the inner reference. */
- base = TREE_OPERAND (t, 0);
- switch (TREE_CODE (base))
+/* CTOR is CONSTRUCTOR of an aggregate or vector.
+ Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */
+
+static tree
+fold_nonarray_ctor_reference (tree type, tree ctor,
+ unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size)
+{
+ unsigned HOST_WIDE_INT cnt;
+ tree cfield, cval;
+
+ FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield,
+ cval)
+ {
+ tree byte_offset = DECL_FIELD_OFFSET (cfield);
+ tree field_offset = DECL_FIELD_BIT_OFFSET (cfield);
+ tree field_size = DECL_SIZE (cfield);
+ double_int bitoffset;
+ double_int byte_offset_cst = tree_to_double_int (byte_offset);
+ double_int bits_per_unit_cst = uhwi_to_double_int (BITS_PER_UNIT);
+ double_int bitoffset_end;
+
+ /* Variable sized objects in static constructors makes no sense,
+ but field_size can be NULL for flexible array members. */
+ gcc_assert (TREE_CODE (field_offset) == INTEGER_CST
+ && TREE_CODE (byte_offset) == INTEGER_CST
+ && (field_size != NULL_TREE
+ ? TREE_CODE (field_size) == INTEGER_CST
+ : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE));
+
+ /* Compute bit offset of the field. */
+ bitoffset = double_int_add (tree_to_double_int (field_offset),
+ double_int_mul (byte_offset_cst,
+ bits_per_unit_cst));
+ /* Compute bit offset where the field ends. */
+ if (field_size != NULL_TREE)
+ bitoffset_end = double_int_add (bitoffset,
+ tree_to_double_int (field_size));
+ else
+ bitoffset_end = double_int_zero;
+
+ /* Is OFFSET in the range (BITOFFSET, BITOFFSET_END)? */
+ if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 0) >= 0
+ && (field_size == NULL_TREE
+ || double_int_cmp (uhwi_to_double_int (offset),
+ bitoffset_end, 0) < 0))
{
- case VAR_DECL:
- if (!TREE_READONLY (base)
- || TREE_CODE (TREE_TYPE (base)) != RECORD_TYPE
- || !targetm.binds_local_p (base))
+ double_int access_end = double_int_add (uhwi_to_double_int (offset),
+ uhwi_to_double_int (size));
+ double_int inner_offset = double_int_sub (uhwi_to_double_int (offset),
+ bitoffset);
+ /* We do have overlap. Now see if field is large enough to
+ cover the access. Give up for accesses spanning multiple
+ fields. */
+ if (double_int_cmp (access_end, bitoffset_end, 0) > 0)
return NULL_TREE;
+ return fold_ctor_reference (type, cval,
+ double_int_to_uhwi (inner_offset), size);
+ }
+ }
+ /* When memory is not explicitely mentioned in constructor, it is 0. */
+ return build_zero_cst (type);
+}
- ctor = DECL_INITIAL (base);
- break;
+/* CTOR is value initializing memory, fold reference of type TYPE and size SIZE
+ to the memory at bit OFFSET. */
- case ARRAY_REF:
- case COMPONENT_REF:
- ctor = fold_const_aggregate_ref (base);
- break;
+static tree
+fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size)
+{
+ tree ret;
+
+ /* We found the field with exact match. */
+ if (useless_type_conversion_p (type, TREE_TYPE (ctor))
+ && !offset)
+ return canonicalize_constructor_val (ctor);
+
+ /* We are at the end of walk, see if we can view convert the
+ result. */
+ if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset
+ /* VIEW_CONVERT_EXPR is defined only for matching sizes. */
+ && operand_equal_p (TYPE_SIZE (type),
+ TYPE_SIZE (TREE_TYPE (ctor)), 0))
+ {
+ ret = canonicalize_constructor_val (ctor);
+ ret = fold_unary (VIEW_CONVERT_EXPR, type, ret);
+ if (ret)
+ STRIP_NOPS (ret);
+ return ret;
+ }
+ if (TREE_CODE (ctor) == STRING_CST)
+ return fold_string_cst_ctor_reference (type, ctor, offset, size);
+ if (TREE_CODE (ctor) == CONSTRUCTOR)
+ {
- default:
- return NULL_TREE;
- }
+ if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE)
+ return fold_array_ctor_reference (type, ctor, offset, size);
+ else
+ return fold_nonarray_ctor_reference (type, ctor, offset, size);
+ }
+
+ return NULL_TREE;
+}
+
+/* Return the tree representing the element referenced by T if T is an
+ ARRAY_REF or COMPONENT_REF into constant aggregates. Return
+ NULL_TREE otherwise. */
+
+tree
+fold_const_aggregate_ref (tree t)
+{
+ tree ctor, idx, base;
+ HOST_WIDE_INT offset, size, max_size;
+ tree tem;
- if (ctor == NULL_TREE
- || TREE_CODE (ctor) != CONSTRUCTOR
- || !TREE_STATIC (ctor))
+ if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration)
+ return get_symbol_constant_value (t);
+
+ tem = fold_read_from_constant_string (t);
+ if (tem)
+ return tem;
+
+ switch (TREE_CODE (t))
+ {
+ case ARRAY_REF:
+ case ARRAY_RANGE_REF:
+ /* Constant indexes are handled well by get_base_constructor.
+ Only special case variable offsets.
+ FIXME: This code can't handle nested references with variable indexes
+ (they will be handled only by iteration of ccp). Perhaps we can bring
+ get_ref_base_and_extent here and make it use get_constant_value. */
+ if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME
+ && (idx = get_constant_value (TREE_OPERAND (t, 1)))
+ && host_integerp (idx, 0))
+ {
+ tree low_bound, unit_size;
+
+ /* If the resulting bit-offset is constant, track it. */
+ if ((low_bound = array_ref_low_bound (t),
+ host_integerp (low_bound, 0))
+ && (unit_size = array_ref_element_size (t),
+ host_integerp (unit_size, 1)))
+ {
+ offset = TREE_INT_CST_LOW (idx);
+ offset -= TREE_INT_CST_LOW (low_bound);
+ offset *= TREE_INT_CST_LOW (unit_size);
+ offset *= BITS_PER_UNIT;
+
+ base = TREE_OPERAND (t, 0);
+ ctor = get_base_constructor (base, &offset);
+ /* Empty constructor. Always fold to 0. */
+ if (ctor == error_mark_node)
+ return build_zero_cst (TREE_TYPE (t));
+ /* Out of bound array access. Value is undefined, but don't fold. */
+ if (offset < 0)
+ return NULL_TREE;
+ /* We can not determine ctor. */
+ if (!ctor)
+ return NULL_TREE;
+ return fold_ctor_reference (TREE_TYPE (t), ctor, offset,
+ TREE_INT_CST_LOW (unit_size)
+ * BITS_PER_UNIT);
+ }
+ }
+ /* Fallthru. */
+
+ case COMPONENT_REF:
+ case BIT_FIELD_REF:
+ case TARGET_MEM_REF:
+ case MEM_REF:
+ base = get_ref_base_and_extent (t, &offset, &size, &max_size);
+ ctor = get_base_constructor (base, &offset);
+
+ /* Empty constructor. Always fold to 0. */
+ if (ctor == error_mark_node)
+ return build_zero_cst (TREE_TYPE (t));
+ /* We do not know precise address. */
+ if (max_size == -1 || max_size != size)
+ return NULL_TREE;
+ /* We can not determine ctor. */
+ if (!ctor)
return NULL_TREE;
- field = TREE_OPERAND (t, 1);
+ /* Out of bound array access. Value is undefined, but don't fold. */
+ if (offset < 0)
+ return NULL_TREE;
- FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
- if (cfield == field
- /* FIXME: Handle bit-fields. */
- && ! DECL_BIT_FIELD (cfield))
- {
- STRIP_NOPS (cval);
- if (TREE_CODE (cval) == ADDR_EXPR)
- {
- tree base = get_base_address (TREE_OPERAND (cval, 0));
- if (base && TREE_CODE (base) == VAR_DECL)
- add_referenced_var (base);
- }
- return cval;
- }
- break;
+ return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size);
case REALPART_EXPR:
case IMAGPART_EXPR:
break;
}
- case MEM_REF:
- /* Get the base object we are accessing. */
- base = TREE_OPERAND (t, 0);
- if (TREE_CODE (base) == SSA_NAME
- && (tem = get_constant_value (base)))
- base = tem;
- if (TREE_CODE (base) != ADDR_EXPR)
- return NULL_TREE;
- base = TREE_OPERAND (base, 0);
- switch (TREE_CODE (base))
- {
- case VAR_DECL:
- if (DECL_P (base)
- && !AGGREGATE_TYPE_P (TREE_TYPE (base))
- && integer_zerop (TREE_OPERAND (t, 1)))
- {
- tree res = get_symbol_constant_value (base);
- if (res
- && !useless_type_conversion_p
- (TREE_TYPE (t), TREE_TYPE (res)))
- res = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (t), res);
- return res;
- }
+ default:
+ break;
+ }
- if (!TREE_READONLY (base)
- || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE
- || !targetm.binds_local_p (base))
- return NULL_TREE;
+ return NULL_TREE;
+}
- ctor = DECL_INITIAL (base);
- break;
+/* Apply the operation CODE in type TYPE to the value, mask pair
+ RVAL and RMASK representing a value of type RTYPE and set
+ the value, mask pair *VAL and *MASK to the result. */
- case STRING_CST:
- case CONSTRUCTOR:
- ctor = base;
- break;
+static void
+bit_value_unop_1 (enum tree_code code, tree type,
+ double_int *val, double_int *mask,
+ tree rtype, double_int rval, double_int rmask)
+{
+ switch (code)
+ {
+ case BIT_NOT_EXPR:
+ *mask = rmask;
+ *val = double_int_not (rval);
+ break;
- default:
- return NULL_TREE;
- }
+ case NEGATE_EXPR:
+ {
+ double_int temv, temm;
+ /* Return ~rval + 1. */
+ bit_value_unop_1 (BIT_NOT_EXPR, type, &temv, &temm, type, rval, rmask);
+ bit_value_binop_1 (PLUS_EXPR, type, val, mask,
+ type, temv, temm,
+ type, double_int_one, double_int_zero);
+ break;
+ }
- if (ctor == NULL_TREE
- || (TREE_CODE (ctor) != CONSTRUCTOR
- && TREE_CODE (ctor) != STRING_CST)
- || !TREE_STATIC (ctor))
- return NULL_TREE;
+ CASE_CONVERT:
+ {
+ bool uns;
+
+ /* First extend mask and value according to the original type. */
+ uns = (TREE_CODE (rtype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (rtype)
+ ? 0 : TYPE_UNSIGNED (rtype));
+ *mask = double_int_ext (rmask, TYPE_PRECISION (rtype), uns);
+ *val = double_int_ext (rval, TYPE_PRECISION (rtype), uns);
+
+ /* Then extend mask and value according to the target type. */
+ uns = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
+ ? 0 : TYPE_UNSIGNED (type));
+ *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns);
+ *val = double_int_ext (*val, TYPE_PRECISION (type), uns);
+ break;
+ }
- /* Get the byte offset. */
- idx = TREE_OPERAND (t, 1);
+ default:
+ *mask = double_int_minus_one;
+ break;
+ }
+}
- /* Fold read from constant string. */
- if (TREE_CODE (ctor) == STRING_CST)
+/* Apply the operation CODE in type TYPE to the value, mask pairs
+ R1VAL, R1MASK and R2VAL, R2MASK representing a values of type R1TYPE
+ and R2TYPE and set the value, mask pair *VAL and *MASK to the result. */
+
+static void
+bit_value_binop_1 (enum tree_code code, tree type,
+ double_int *val, double_int *mask,
+ tree r1type, double_int r1val, double_int r1mask,
+ tree r2type, double_int r2val, double_int r2mask)
+{
+ bool uns = (TREE_CODE (type) == INTEGER_TYPE
+ && TYPE_IS_SIZETYPE (type) ? 0 : TYPE_UNSIGNED (type));
+ /* Assume we'll get a constant result. Use an initial varying value,
+ we fall back to varying in the end if necessary. */
+ *mask = double_int_minus_one;
+ switch (code)
+ {
+ case BIT_AND_EXPR:
+ /* The mask is constant where there is a known not
+ set bit, (m1 | m2) & ((v1 | m1) & (v2 | m2)) */
+ *mask = double_int_and (double_int_ior (r1mask, r2mask),
+ double_int_and (double_int_ior (r1val, r1mask),
+ double_int_ior (r2val, r2mask)));
+ *val = double_int_and (r1val, r2val);
+ break;
+
+ case BIT_IOR_EXPR:
+ /* The mask is constant where there is a known
+ set bit, (m1 | m2) & ~((v1 & ~m1) | (v2 & ~m2)). */
+ *mask = double_int_and_not
+ (double_int_ior (r1mask, r2mask),
+ double_int_ior (double_int_and_not (r1val, r1mask),
+ double_int_and_not (r2val, r2mask)));
+ *val = double_int_ior (r1val, r2val);
+ break;
+
+ case BIT_XOR_EXPR:
+ /* m1 | m2 */
+ *mask = double_int_ior (r1mask, r2mask);
+ *val = double_int_xor (r1val, r2val);
+ break;
+
+ case LROTATE_EXPR:
+ case RROTATE_EXPR:
+ if (double_int_zero_p (r2mask))
{
- if ((TYPE_MODE (TREE_TYPE (t))
- == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
- && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
- == MODE_INT)
- && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1
- && compare_tree_int (idx, TREE_STRING_LENGTH (ctor)) < 0)
- return build_int_cst_type (TREE_TYPE (t),
- (TREE_STRING_POINTER (ctor)
- [TREE_INT_CST_LOW (idx)]));
- return NULL_TREE;
+ HOST_WIDE_INT shift = r2val.low;
+ if (code == RROTATE_EXPR)
+ shift = -shift;
+ *mask = double_int_lrotate (r1mask, shift, TYPE_PRECISION (type));
+ *val = double_int_lrotate (r1val, shift, TYPE_PRECISION (type));
}
+ break;
- /* ??? Implement byte-offset indexing into a non-array CONSTRUCTOR. */
- if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE
- && (TYPE_MODE (TREE_TYPE (t))
- == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor))))
- && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (t))) != 0
- && integer_zerop
- (int_const_binop
- (TRUNC_MOD_EXPR, idx,
- size_int (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (t)))), 0)))
+ case LSHIFT_EXPR:
+ case RSHIFT_EXPR:
+ /* ??? We can handle partially known shift counts if we know
+ its sign. That way we can tell that (x << (y | 8)) & 255
+ is zero. */
+ if (double_int_zero_p (r2mask))
{
- idx = int_const_binop (TRUNC_DIV_EXPR, idx,
- size_int (GET_MODE_SIZE
- (TYPE_MODE (TREE_TYPE (t)))), 0);
- FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval)
- if (tree_int_cst_equal (cfield, idx))
- {
- STRIP_NOPS (cval);
- if (TREE_CODE (cval) == ADDR_EXPR)
- {
- tree base = get_base_address (TREE_OPERAND (cval, 0));
- if (base && TREE_CODE (base) == VAR_DECL)
- add_referenced_var (base);
- }
- if (useless_type_conversion_p (TREE_TYPE (t), TREE_TYPE (cval)))
- return cval;
- else if (CONSTANT_CLASS_P (cval))
- return fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (t), cval);
- else
- return NULL_TREE;
- }
+ HOST_WIDE_INT shift = r2val.low;
+ if (code == RSHIFT_EXPR)
+ shift = -shift;
+ /* We need to know if we are doing a left or a right shift
+ to properly shift in zeros for left shift and unsigned
+ right shifts and the sign bit for signed right shifts.
+ For signed right shifts we shift in varying in case
+ the sign bit was varying. */
+ if (shift > 0)
+ {
+ *mask = double_int_lshift (r1mask, shift,
+ TYPE_PRECISION (type), false);
+ *val = double_int_lshift (r1val, shift,
+ TYPE_PRECISION (type), false);
+ }
+ else if (shift < 0)
+ {
+ shift = -shift;
+ *mask = double_int_rshift (r1mask, shift,
+ TYPE_PRECISION (type), !uns);
+ *val = double_int_rshift (r1val, shift,
+ TYPE_PRECISION (type), !uns);
+ }
+ else
+ {
+ *mask = r1mask;
+ *val = r1val;
+ }
}
break;
- default:
- break;
+ case PLUS_EXPR:
+ case POINTER_PLUS_EXPR:
+ {
+ double_int lo, hi;
+ /* Do the addition with unknown bits set to zero, to give carry-ins of
+ zero wherever possible. */
+ lo = double_int_add (double_int_and_not (r1val, r1mask),
+ double_int_and_not (r2val, r2mask));
+ lo = double_int_ext (lo, TYPE_PRECISION (type), uns);
+ /* Do the addition with unknown bits set to one, to give carry-ins of
+ one wherever possible. */
+ hi = double_int_add (double_int_ior (r1val, r1mask),
+ double_int_ior (r2val, r2mask));
+ hi = double_int_ext (hi, TYPE_PRECISION (type), uns);
+ /* Each bit in the result is known if (a) the corresponding bits in
+ both inputs are known, and (b) the carry-in to that bit position
+ is known. We can check condition (b) by seeing if we got the same
+ result with minimised carries as with maximised carries. */
+ *mask = double_int_ior (double_int_ior (r1mask, r2mask),
+ double_int_xor (lo, hi));
+ *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns);
+ /* It shouldn't matter whether we choose lo or hi here. */
+ *val = lo;
+ break;
+ }
+
+ case MINUS_EXPR:
+ {
+ double_int temv, temm;
+ bit_value_unop_1 (NEGATE_EXPR, r2type, &temv, &temm,
+ r2type, r2val, r2mask);
+ bit_value_binop_1 (PLUS_EXPR, type, val, mask,
+ r1type, r1val, r1mask,
+ r2type, temv, temm);
+ break;
+ }
+
+ case MULT_EXPR:
+ {
+ /* Just track trailing zeros in both operands and transfer
+ them to the other. */
+ int r1tz = double_int_ctz (double_int_ior (r1val, r1mask));
+ int r2tz = double_int_ctz (double_int_ior (r2val, r2mask));
+ if (r1tz + r2tz >= HOST_BITS_PER_DOUBLE_INT)
+ {
+ *mask = double_int_zero;
+ *val = double_int_zero;
+ }
+ else if (r1tz + r2tz > 0)
+ {
+ *mask = double_int_not (double_int_mask (r1tz + r2tz));
+ *mask = double_int_ext (*mask, TYPE_PRECISION (type), uns);
+ *val = double_int_zero;
+ }
+ break;
+ }
+
+ case EQ_EXPR:
+ case NE_EXPR:
+ {
+ double_int m = double_int_ior (r1mask, r2mask);
+ if (!double_int_equal_p (double_int_and_not (r1val, m),
+ double_int_and_not (r2val, m)))
+ {
+ *mask = double_int_zero;
+ *val = ((code == EQ_EXPR) ? double_int_zero : double_int_one);
+ }
+ else
+ {
+ /* We know the result of a comparison is always one or zero. */
+ *mask = double_int_one;
+ *val = double_int_zero;
+ }
+ break;
+ }
+
+ case GE_EXPR:
+ case GT_EXPR:
+ {
+ double_int tem = r1val;
+ r1val = r2val;
+ r2val = tem;
+ tem = r1mask;
+ r1mask = r2mask;
+ r2mask = tem;
+ code = swap_tree_comparison (code);
+ }
+ /* Fallthru. */
+ case LT_EXPR:
+ case LE_EXPR:
+ {
+ int minmax, maxmin;
+ /* If the most significant bits are not known we know nothing. */
+ if (double_int_negative_p (r1mask) || double_int_negative_p (r2mask))
+ break;
+
+ /* If we know the most significant bits we know the values
+ value ranges by means of treating varying bits as zero
+ or one. Do a cross comparison of the max/min pairs. */
+ maxmin = double_int_cmp (double_int_ior (r1val, r1mask),
+ double_int_and_not (r2val, r2mask), uns);
+ minmax = double_int_cmp (double_int_and_not (r1val, r1mask),
+ double_int_ior (r2val, r2mask), uns);
+ if (maxmin < 0) /* r1 is less than r2. */
+ {
+ *mask = double_int_zero;
+ *val = double_int_one;
+ }
+ else if (minmax > 0) /* r1 is not less or equal to r2. */
+ {
+ *mask = double_int_zero;
+ *val = double_int_zero;
+ }
+ else if (maxmin == minmax) /* r1 and r2 are equal. */
+ {
+ /* This probably should never happen as we'd have
+ folded the thing during fully constant value folding. */
+ *mask = double_int_zero;
+ *val = (code == LE_EXPR ? double_int_one : double_int_zero);
+ }
+ else
+ {
+ /* We know the result of a comparison is always one or zero. */
+ *mask = double_int_one;
+ *val = double_int_zero;
+ }
+ break;
+ }
+
+ default:;
}
+}
- return NULL_TREE;
+/* Return the propagation value when applying the operation CODE to
+ the value RHS yielding type TYPE. */
+
+static prop_value_t
+bit_value_unop (enum tree_code code, tree type, tree rhs)
+{
+ prop_value_t rval = get_value_for_expr (rhs, true);
+ double_int value, mask;
+ prop_value_t val;
+ gcc_assert ((rval.lattice_val == CONSTANT
+ && TREE_CODE (rval.value) == INTEGER_CST)
+ || double_int_minus_one_p (rval.mask));
+ bit_value_unop_1 (code, type, &value, &mask,
+ TREE_TYPE (rhs), value_to_double_int (rval), rval.mask);
+ if (!double_int_minus_one_p (mask))
+ {
+ val.lattice_val = CONSTANT;
+ val.mask = mask;
+ /* ??? Delay building trees here. */
+ val.value = double_int_to_tree (type, value);
+ }
+ else
+ {
+ val.lattice_val = VARYING;
+ val.value = NULL_TREE;
+ val.mask = double_int_minus_one;
+ }
+ return val;
+}
+
+/* Return the propagation value when applying the operation CODE to
+ the values RHS1 and RHS2 yielding type TYPE. */
+
+static prop_value_t
+bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2)
+{
+ prop_value_t r1val = get_value_for_expr (rhs1, true);
+ prop_value_t r2val = get_value_for_expr (rhs2, true);
+ double_int value, mask;
+ prop_value_t val;
+ gcc_assert ((r1val.lattice_val == CONSTANT
+ && TREE_CODE (r1val.value) == INTEGER_CST)
+ || double_int_minus_one_p (r1val.mask));
+ gcc_assert ((r2val.lattice_val == CONSTANT
+ && TREE_CODE (r2val.value) == INTEGER_CST)
+ || double_int_minus_one_p (r2val.mask));
+ bit_value_binop_1 (code, type, &value, &mask,
+ TREE_TYPE (rhs1), value_to_double_int (r1val), r1val.mask,
+ TREE_TYPE (rhs2), value_to_double_int (r2val), r2val.mask);
+ if (!double_int_minus_one_p (mask))
+ {
+ val.lattice_val = CONSTANT;
+ val.mask = mask;
+ /* ??? Delay building trees here. */
+ val.value = double_int_to_tree (type, value);
+ }
+ else
+ {
+ val.lattice_val = VARYING;
+ val.value = NULL_TREE;
+ val.mask = double_int_minus_one;
+ }
+ return val;
}
/* Evaluate statement STMT.
prop_value_t val;
tree simplified = NULL_TREE;
ccp_lattice_t likelyvalue = likely_value (stmt);
- bool is_constant;
+ bool is_constant = false;
- fold_defer_overflow_warnings ();
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "which is likely ");
+ switch (likelyvalue)
+ {
+ case CONSTANT:
+ fprintf (dump_file, "CONSTANT");
+ break;
+ case UNDEFINED:
+ fprintf (dump_file, "UNDEFINED");
+ break;
+ case VARYING:
+ fprintf (dump_file, "VARYING");
+ break;
+ default:;
+ }
+ fprintf (dump_file, "\n");
+ }
/* If the statement is likely to have a CONSTANT result, then try
to fold the statement to determine the constant value. */
Since likely_value never returns CONSTANT for calls, we will
not attempt to fold them, including builtins that may profit. */
if (likelyvalue == CONSTANT)
- simplified = ccp_fold (stmt);
+ {
+ fold_defer_overflow_warnings ();
+ simplified = ccp_fold (stmt);
+ is_constant = simplified && is_gimple_min_invariant (simplified);
+ fold_undefer_overflow_warnings (is_constant, stmt, 0);
+ if (is_constant)
+ {
+ /* The statement produced a constant value. */
+ val.lattice_val = CONSTANT;
+ val.value = simplified;
+ val.mask = double_int_zero;
+ }
+ }
/* If the statement is likely to have a VARYING result, then do not
bother folding the statement. */
else if (likelyvalue == VARYING)
else
/* These cannot satisfy is_gimple_min_invariant without folding. */
gcc_assert (code == GIMPLE_CALL || code == GIMPLE_COND);
+ is_constant = simplified && is_gimple_min_invariant (simplified);
+ if (is_constant)
+ {
+ /* The statement produced a constant value. */
+ val.lattice_val = CONSTANT;
+ val.value = simplified;
+ val.mask = double_int_zero;
+ }
}
- is_constant = simplified && is_gimple_min_invariant (simplified);
-
- fold_undefer_overflow_warnings (is_constant, stmt, 0);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
+ /* Resort to simplification for bitwise tracking. */
+ if (flag_tree_bit_ccp
+ && likelyvalue == CONSTANT
+ && !is_constant)
{
- fprintf (dump_file, "which is likely ");
- switch (likelyvalue)
+ enum gimple_code code = gimple_code (stmt);
+ tree fndecl;
+ val.lattice_val = VARYING;
+ val.value = NULL_TREE;
+ val.mask = double_int_minus_one;
+ if (code == GIMPLE_ASSIGN)
{
- case CONSTANT:
- fprintf (dump_file, "CONSTANT");
- break;
- case UNDEFINED:
- fprintf (dump_file, "UNDEFINED");
- break;
- case VARYING:
- fprintf (dump_file, "VARYING");
- break;
- default:;
+ enum tree_code subcode = gimple_assign_rhs_code (stmt);
+ tree rhs1 = gimple_assign_rhs1 (stmt);
+ switch (get_gimple_rhs_class (subcode))
+ {
+ case GIMPLE_SINGLE_RHS:
+ if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+ || POINTER_TYPE_P (TREE_TYPE (rhs1)))
+ val = get_value_for_expr (rhs1, true);
+ break;
+
+ case GIMPLE_UNARY_RHS:
+ if ((INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+ || POINTER_TYPE_P (TREE_TYPE (rhs1)))
+ && (INTEGRAL_TYPE_P (gimple_expr_type (stmt))
+ || POINTER_TYPE_P (gimple_expr_type (stmt))))
+ val = bit_value_unop (subcode, gimple_expr_type (stmt), rhs1);
+ break;
+
+ case GIMPLE_BINARY_RHS:
+ if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+ || POINTER_TYPE_P (TREE_TYPE (rhs1)))
+ {
+ tree rhs2 = gimple_assign_rhs2 (stmt);
+ val = bit_value_binop (subcode,
+ TREE_TYPE (rhs1), rhs1, rhs2);
+ }
+ break;
+
+ default:;
+ }
}
- fprintf (dump_file, "\n");
+ else if (code == GIMPLE_COND)
+ {
+ enum tree_code code = gimple_cond_code (stmt);
+ tree rhs1 = gimple_cond_lhs (stmt);
+ tree rhs2 = gimple_cond_rhs (stmt);
+ if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+ || POINTER_TYPE_P (TREE_TYPE (rhs1)))
+ val = bit_value_binop (code, TREE_TYPE (rhs1), rhs1, rhs2);
+ }
+ else if (code == GIMPLE_CALL
+ && (fndecl = gimple_call_fndecl (stmt))
+ && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+ {
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ case BUILT_IN_MALLOC:
+ case BUILT_IN_REALLOC:
+ case BUILT_IN_CALLOC:
+ val.lattice_val = CONSTANT;
+ val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0);
+ val.mask = shwi_to_double_int
+ (~(((HOST_WIDE_INT) MALLOC_ABI_ALIGNMENT)
+ / BITS_PER_UNIT - 1));
+ break;
+
+ case BUILT_IN_ALLOCA:
+ val.lattice_val = CONSTANT;
+ val.value = build_int_cst (TREE_TYPE (gimple_get_lhs (stmt)), 0);
+ val.mask = shwi_to_double_int
+ (~(((HOST_WIDE_INT) BIGGEST_ALIGNMENT)
+ / BITS_PER_UNIT - 1));
+ break;
+
+ default:;
+ }
+ }
+ is_constant = (val.lattice_val == CONSTANT);
}
- if (is_constant)
- {
- /* The statement produced a constant value. */
- val.lattice_val = CONSTANT;
- val.value = simplified;
- }
- else
+ if (!is_constant)
{
/* The statement produced a nonconstant value. If the statement
had UNDEFINED operands, then the result of the statement
should be UNDEFINED. Otherwise, the statement is VARYING. */
if (likelyvalue == UNDEFINED)
- val.lattice_val = likelyvalue;
+ {
+ val.lattice_val = likelyvalue;
+ val.mask = double_int_zero;
+ }
else
- val.lattice_val = VARYING;
+ {
+ val.lattice_val = VARYING;
+ val.mask = double_int_minus_one;
+ }
val.value = NULL_TREE;
}
fold more conditionals here. */
val = evaluate_stmt (stmt);
if (val.lattice_val != CONSTANT
- || TREE_CODE (val.value) != INTEGER_CST)
+ || !double_int_zero_p (val.mask))
return false;
+ if (dump_file)
+ {
+ fprintf (dump_file, "Folding predicate ");
+ print_gimple_expr (dump_file, stmt, 0, 0);
+ fprintf (dump_file, " to ");
+ print_generic_expr (dump_file, val.value, 0);
+ fprintf (dump_file, "\n");
+ }
+
if (integer_zerop (val.value))
gimple_cond_make_false (stmt);
else
tree lhs = gimple_call_lhs (stmt);
tree val;
tree argt;
+ tree callee;
bool changed = false;
unsigned i;
}
}
+ callee = gimple_call_fn (stmt);
+ if (TREE_CODE (callee) == OBJ_TYPE_REF
+ && TREE_CODE (OBJ_TYPE_REF_EXPR (callee)) == SSA_NAME)
+ {
+ tree expr = OBJ_TYPE_REF_EXPR (callee);
+ OBJ_TYPE_REF_EXPR (callee) = valueize_op (expr);
+ if (TREE_CODE (OBJ_TYPE_REF_EXPR (callee)) == ADDR_EXPR)
+ {
+ tree t;
+ t = gimple_fold_obj_type_ref (callee, NULL_TREE);
+ if (t)
+ {
+ gimple_call_set_fn (stmt, t);
+ changed = true;
+ }
+ }
+ OBJ_TYPE_REF_EXPR (callee) = expr;
+ }
+
return changed;
}
block = gimple_bb (stmt);
val = evaluate_stmt (stmt);
+ if (val.lattice_val != CONSTANT
+ || !double_int_zero_p (val.mask))
+ return SSA_PROP_VARYING;
/* Find which edge out of the conditional block will be taken and add it
to the worklist. If no single edge can be determined statically,
return SSA_PROP_VARYING to feed all the outgoing edges to the
propagation engine. */
- *taken_edge_p = val.value ? find_taken_edge (block, val.value) : 0;
+ *taken_edge_p = find_taken_edge (block, val.value);
if (*taken_edge_p)
return SSA_PROP_INTERESTING;
else
Mark them VARYING. */
FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_ALL_DEFS)
{
- prop_value_t v = { VARYING, NULL_TREE };
+ prop_value_t v = { VARYING, NULL_TREE, { -1, (HOST_WIDE_INT) -1 } };
set_lattice_value (def, v);
}
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