+
+
+/* Fold STMT to a constant using VALUEIZE to valueize SSA names.
+
+ Either NULL_TREE, a simplified but non-constant or a constant
+ is returned.
+
+ ??? This should go into a gimple-fold-inline.h file to be eventually
+ privatized with the single valueize function used in the various TUs
+ to avoid the indirect function call overhead. */
+
+tree
+gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree))
+{
+ location_t loc = gimple_location (stmt);
+ switch (gimple_code (stmt))
+ {
+ case GIMPLE_ASSIGN:
+ {
+ enum tree_code subcode = gimple_assign_rhs_code (stmt);
+
+ switch (get_gimple_rhs_class (subcode))
+ {
+ case GIMPLE_SINGLE_RHS:
+ {
+ tree rhs = gimple_assign_rhs1 (stmt);
+ enum tree_code_class kind = TREE_CODE_CLASS (subcode);
+
+ if (TREE_CODE (rhs) == SSA_NAME)
+ {
+ /* If the RHS is an SSA_NAME, return its known constant value,
+ if any. */
+ return (*valueize) (rhs);
+ }
+ /* Handle propagating invariant addresses into address
+ operations. */
+ else if (TREE_CODE (rhs) == ADDR_EXPR
+ && !is_gimple_min_invariant (rhs))
+ {
+ HOST_WIDE_INT offset;
+ tree base;
+ base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0),
+ &offset,
+ valueize);
+ if (base
+ && (CONSTANT_CLASS_P (base)
+ || decl_address_invariant_p (base)))
+ return build_invariant_address (TREE_TYPE (rhs),
+ base, offset);
+ }
+ else if (TREE_CODE (rhs) == CONSTRUCTOR
+ && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE
+ && (CONSTRUCTOR_NELTS (rhs)
+ == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))))
+ {
+ unsigned i;
+ tree val, list;
+
+ list = NULL_TREE;
+ FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val)
+ {
+ val = (*valueize) (val);
+ if (TREE_CODE (val) == INTEGER_CST
+ || TREE_CODE (val) == REAL_CST
+ || TREE_CODE (val) == FIXED_CST)
+ list = tree_cons (NULL_TREE, val, list);
+ else
+ return NULL_TREE;
+ }
+
+ return build_vector (TREE_TYPE (rhs), nreverse (list));
+ }
+
+ if (kind == tcc_reference)
+ {
+ if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR
+ || TREE_CODE (rhs) == REALPART_EXPR
+ || TREE_CODE (rhs) == IMAGPART_EXPR)
+ && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
+ {
+ tree val = (*valueize) (TREE_OPERAND (rhs, 0));
+ return fold_unary_loc (EXPR_LOCATION (rhs),
+ TREE_CODE (rhs),
+ TREE_TYPE (rhs), val);
+ }
+ else if (TREE_CODE (rhs) == BIT_FIELD_REF
+ && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
+ {
+ tree val = (*valueize) (TREE_OPERAND (rhs, 0));
+ return fold_ternary_loc (EXPR_LOCATION (rhs),
+ TREE_CODE (rhs),
+ TREE_TYPE (rhs), val,
+ TREE_OPERAND (rhs, 1),
+ TREE_OPERAND (rhs, 2));
+ }
+ else if (TREE_CODE (rhs) == MEM_REF
+ && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME)
+ {
+ tree val = (*valueize) (TREE_OPERAND (rhs, 0));
+ if (TREE_CODE (val) == ADDR_EXPR
+ && is_gimple_min_invariant (val))
+ {
+ tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs),
+ unshare_expr (val),
+ TREE_OPERAND (rhs, 1));
+ if (tem)
+ rhs = tem;
+ }
+ }
+ return fold_const_aggregate_ref_1 (rhs, valueize);
+ }
+ else if (kind == tcc_declaration)
+ return get_symbol_constant_value (rhs);
+ return rhs;
+ }
+
+ case GIMPLE_UNARY_RHS:
+ {
+ /* Handle unary operators that can appear in GIMPLE form.
+ Note that we know the single operand must be a constant,
+ so this should almost always return a simplified RHS. */
+ tree lhs = gimple_assign_lhs (stmt);
+ tree op0 = (*valueize) (gimple_assign_rhs1 (stmt));
+
+ /* Conversions are useless for CCP purposes if they are
+ value-preserving. Thus the restrictions that
+ useless_type_conversion_p places for restrict qualification
+ of pointer types should not apply here.
+ Substitution later will only substitute to allowed places. */
+ if (CONVERT_EXPR_CODE_P (subcode)
+ && POINTER_TYPE_P (TREE_TYPE (lhs))
+ && POINTER_TYPE_P (TREE_TYPE (op0))
+ && TYPE_ADDR_SPACE (TREE_TYPE (lhs))
+ == TYPE_ADDR_SPACE (TREE_TYPE (op0))
+ && TYPE_MODE (TREE_TYPE (lhs))
+ == TYPE_MODE (TREE_TYPE (op0)))
+ return op0;
+
+ return
+ fold_unary_ignore_overflow_loc (loc, subcode,
+ gimple_expr_type (stmt), op0);
+ }
+
+ case GIMPLE_BINARY_RHS:
+ {
+ /* Handle binary operators that can appear in GIMPLE form. */
+ tree op0 = (*valueize) (gimple_assign_rhs1 (stmt));
+ tree op1 = (*valueize) (gimple_assign_rhs2 (stmt));
+
+ /* Translate &x + CST into an invariant form suitable for
+ further propagation. */
+ if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
+ && TREE_CODE (op0) == ADDR_EXPR
+ && TREE_CODE (op1) == INTEGER_CST)
+ {
+ tree off = fold_convert (ptr_type_node, op1);
+ return build_fold_addr_expr_loc
+ (loc,
+ fold_build2 (MEM_REF,
+ TREE_TYPE (TREE_TYPE (op0)),
+ unshare_expr (op0), off));
+ }
+
+ return fold_binary_loc (loc, subcode,
+ gimple_expr_type (stmt), op0, op1);
+ }
+
+ case GIMPLE_TERNARY_RHS:
+ {
+ /* Handle ternary operators that can appear in GIMPLE form. */
+ tree op0 = (*valueize) (gimple_assign_rhs1 (stmt));
+ tree op1 = (*valueize) (gimple_assign_rhs2 (stmt));
+ tree op2 = (*valueize) (gimple_assign_rhs3 (stmt));
+
+ /* Fold embedded expressions in ternary codes. */
+ if ((subcode == COND_EXPR
+ || subcode == VEC_COND_EXPR)
+ && COMPARISON_CLASS_P (op0))
+ {
+ tree op00 = (*valueize) (TREE_OPERAND (op0, 0));
+ tree op01 = (*valueize) (TREE_OPERAND (op0, 1));
+ tree tem = fold_binary_loc (loc, TREE_CODE (op0),
+ TREE_TYPE (op0), op00, op01);
+ if (tem)
+ op0 = tem;
+ }
+
+ return fold_ternary_loc (loc, subcode,
+ gimple_expr_type (stmt), op0, op1, op2);
+ }
+
+ default:
+ gcc_unreachable ();
+ }
+ }
+
+ case GIMPLE_CALL:
+ {
+ tree fn;
+
+ if (gimple_call_internal_p (stmt))
+ /* No folding yet for these functions. */
+ return NULL_TREE;
+
+ fn = (*valueize) (gimple_call_fn (stmt));
+ if (TREE_CODE (fn) == ADDR_EXPR
+ && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL
+ && DECL_BUILT_IN (TREE_OPERAND (fn, 0)))
+ {
+ tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt));
+ tree call, retval;
+ unsigned i;
+ for (i = 0; i < gimple_call_num_args (stmt); ++i)
+ args[i] = (*valueize) (gimple_call_arg (stmt, i));
+ call = build_call_array_loc (loc,
+ gimple_call_return_type (stmt),
+ fn, gimple_call_num_args (stmt), args);
+ retval = fold_call_expr (EXPR_LOCATION (call), call, false);
+ if (retval)
+ /* fold_call_expr wraps the result inside a NOP_EXPR. */
+ STRIP_NOPS (retval);
+ return retval;
+ }
+ return NULL_TREE;
+ }
+
+ default:
+ return NULL_TREE;
+ }
+}
+
+/* Fold STMT to a constant using VALUEIZE to valueize SSA names.
+ Returns NULL_TREE if folding to a constant is not possible, otherwise
+ returns a constant according to is_gimple_min_invariant. */
+
+tree
+gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree))
+{
+ tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize);
+ if (res && is_gimple_min_invariant (res))
+ return res;
+ return NULL_TREE;
+}
+
+
+/* The following set of functions are supposed to fold references using
+ their constant initializers. */
+
+static tree fold_ctor_reference (tree type, tree ctor,
+ unsigned HOST_WIDE_INT offset,
+ unsigned HOST_WIDE_INT size);
+
+/* 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.
+
+ 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 (*valueize)(tree))
+{
+ 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 (valueize
+ && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
+ base = valueize (TREE_OPERAND (base, 0));
+ if (!base || TREE_CODE (base) != ADDR_EXPR)
+ return NULL_TREE;
+ base = TREE_OPERAND (base, 0);
+ }
+
+ /* 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:
+ 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, valueize);
+
+ case STRING_CST:
+ case CONSTRUCTOR:
+ return base;
+
+ default:
+ return NULL_TREE;
+ }
+}
+
+/* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE
+ to the memory at bit OFFSET.
+
+ We do only simple job of folding byte accesses. */
+
+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;
+}
+
+/* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size
+ SIZE to the memory at bit OFFSET. */
+
+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 = NULL_TREE;
+ HOST_WIDE_INT inner_offset;
+
+ /* Compute low bound and elt size. */
+ if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE)
+ domain_type = TYPE_DOMAIN (TREE_TYPE (ctor));
+ 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;
+
+ /* 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);
+
+ /* 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;
+
+ 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 (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);
+
+ /* 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);
+}
+
+/* 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, access_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;
+
+ access_end = double_int_add (uhwi_to_double_int (offset),
+ uhwi_to_double_int (size));
+
+ /* Is there any overlap between [OFFSET, OFFSET+SIZE) and
+ [BITOFFSET, BITOFFSET_END)? */
+ if (double_int_cmp (access_end, bitoffset, 0) > 0
+ && (field_size == NULL_TREE
+ || double_int_cmp (uhwi_to_double_int (offset),
+ bitoffset_end, 0) < 0))
+ {
+ 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;
+ if (double_int_cmp (uhwi_to_double_int (offset), bitoffset, 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 is value initializing memory, fold reference of type TYPE and size SIZE
+ to the memory at bit OFFSET. */
+
+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)
+ {
+
+ if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE
+ || TREE_CODE (TREE_TYPE (ctor)) == VECTOR_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 valuezing SSA
+ names using VALUEIZE. Return NULL_TREE otherwise. */
+
+tree
+fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree))
+{
+ tree ctor, idx, base;
+ HOST_WIDE_INT offset, size, max_size;
+ tree tem;
+
+ if (TREE_THIS_VOLATILE (t))
+ return NULL_TREE;
+
+ 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 a valueize callback. */
+ if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME
+ && valueize
+ && (idx = (*valueize) (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, valueize);
+ /* 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, valueize);
+
+ /* 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;
+
+ /* Out of bound array access. Value is undefined, but don't fold. */
+ if (offset < 0)
+ return NULL_TREE;
+
+ return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size);
+
+ case REALPART_EXPR:
+ case IMAGPART_EXPR:
+ {
+ tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize);
+ if (c && TREE_CODE (c) == COMPLEX_CST)
+ return fold_build1_loc (EXPR_LOCATION (t),
+ TREE_CODE (t), TREE_TYPE (t), c);
+ break;
+ }
+
+ default:
+ break;
+ }
+
+ return NULL_TREE;
+}
+
+tree
+fold_const_aggregate_ref (tree t)
+{
+ return fold_const_aggregate_ref_1 (t, NULL);
+}
+
+/* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN
+ is integer form of OBJ_TYPE_REF_TOKEN of the reference expression.
+ KNOWN_BINFO carries the binfo describing the true type of
+ OBJ_TYPE_REF_OBJECT(REF). */
+
+tree
+gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo)
+{
+ unsigned HOST_WIDE_INT offset, size;
+ tree v, fn;
+
+ v = BINFO_VTABLE (known_binfo);
+ /* If there is no virtual methods table, leave the OBJ_TYPE_REF alone. */
+ if (!v)
+ return NULL_TREE;
+
+ if (TREE_CODE (v) == POINTER_PLUS_EXPR)
+ {
+ offset = tree_low_cst (TREE_OPERAND (v, 1), 1) * BITS_PER_UNIT;
+ v = TREE_OPERAND (v, 0);
+ }
+ else
+ offset = 0;
+
+ if (TREE_CODE (v) != ADDR_EXPR)
+ return NULL_TREE;
+ v = TREE_OPERAND (v, 0);
+
+ if (TREE_CODE (v) != VAR_DECL
+ || !DECL_VIRTUAL_P (v)
+ || !DECL_INITIAL (v)
+ || DECL_INITIAL (v) == error_mark_node)
+ return NULL_TREE;
+ gcc_checking_assert (TREE_CODE (TREE_TYPE (v)) == ARRAY_TYPE);
+ size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (v))), 1);
+ offset += token * size;
+ fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), DECL_INITIAL (v),
+ offset, size);
+ if (!fn)
+ return NULL_TREE;
+ gcc_assert (TREE_CODE (fn) == ADDR_EXPR
+ || TREE_CODE (fn) == FDESC_EXPR);
+ fn = TREE_OPERAND (fn, 0);
+ gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
+
+ /* When cgraph node is missing and function is not public, we cannot
+ devirtualize. This can happen in WHOPR when the actual method
+ ends up in other partition, because we found devirtualization
+ possibility too late. */
+ if (!can_refer_decl_in_current_unit_p (fn))
+ return NULL_TREE;
+
+ return fn;
+}
+
+/* Return true iff VAL is a gimple expression that is known to be
+ non-negative. Restricted to floating-point inputs. */
+
+bool
+gimple_val_nonnegative_real_p (tree val)
+{
+ gimple def_stmt;
+
+ gcc_assert (val && SCALAR_FLOAT_TYPE_P (TREE_TYPE (val)));
+
+ /* Use existing logic for non-gimple trees. */
+ if (tree_expr_nonnegative_p (val))
+ return true;
+
+ if (TREE_CODE (val) != SSA_NAME)
+ return false;
+
+ /* Currently we look only at the immediately defining statement
+ to make this determination, since recursion on defining
+ statements of operands can lead to quadratic behavior in the
+ worst case. This is expected to catch almost all occurrences
+ in practice. It would be possible to implement limited-depth
+ recursion if important cases are lost. Alternatively, passes
+ that need this information (such as the pow/powi lowering code
+ in the cse_sincos pass) could be revised to provide it through
+ dataflow propagation. */
+
+ def_stmt = SSA_NAME_DEF_STMT (val);
+
+ if (is_gimple_assign (def_stmt))
+ {
+ tree op0, op1;
+
+ /* See fold-const.c:tree_expr_nonnegative_p for additional
+ cases that could be handled with recursion. */
+
+ switch (gimple_assign_rhs_code (def_stmt))
+ {
+ case ABS_EXPR:
+ /* Always true for floating-point operands. */
+ return true;
+
+ case MULT_EXPR:
+ /* True if the two operands are identical (since we are
+ restricted to floating-point inputs). */
+ op0 = gimple_assign_rhs1 (def_stmt);
+ op1 = gimple_assign_rhs2 (def_stmt);
+
+ if (op0 == op1
+ || operand_equal_p (op0, op1, 0))
+ return true;
+
+ default:
+ return false;
+ }
+ }
+ else if (is_gimple_call (def_stmt))
+ {
+ tree fndecl = gimple_call_fndecl (def_stmt);
+ if (fndecl
+ && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
+ {
+ tree arg1;
+
+ switch (DECL_FUNCTION_CODE (fndecl))
+ {
+ CASE_FLT_FN (BUILT_IN_ACOS):
+ CASE_FLT_FN (BUILT_IN_ACOSH):
+ CASE_FLT_FN (BUILT_IN_CABS):
+ CASE_FLT_FN (BUILT_IN_COSH):
+ CASE_FLT_FN (BUILT_IN_ERFC):
+ CASE_FLT_FN (BUILT_IN_EXP):
+ CASE_FLT_FN (BUILT_IN_EXP10):
+ CASE_FLT_FN (BUILT_IN_EXP2):
+ CASE_FLT_FN (BUILT_IN_FABS):
+ CASE_FLT_FN (BUILT_IN_FDIM):
+ CASE_FLT_FN (BUILT_IN_HYPOT):
+ CASE_FLT_FN (BUILT_IN_POW10):
+ return true;
+
+ CASE_FLT_FN (BUILT_IN_SQRT):
+ /* sqrt(-0.0) is -0.0, and sqrt is not defined over other
+ nonnegative inputs. */
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (val))))
+ return true;
+
+ break;
+
+ CASE_FLT_FN (BUILT_IN_POWI):
+ /* True if the second argument is an even integer. */
+ arg1 = gimple_call_arg (def_stmt, 1);
+
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && (TREE_INT_CST_LOW (arg1) & 1) == 0)
+ return true;
+
+ break;
+
+ CASE_FLT_FN (BUILT_IN_POW):
+ /* True if the second argument is an even integer-valued
+ real. */
+ arg1 = gimple_call_arg (def_stmt, 1);
+
+ if (TREE_CODE (arg1) == REAL_CST)
+ {
+ REAL_VALUE_TYPE c;
+ HOST_WIDE_INT n;
+
+ c = TREE_REAL_CST (arg1);
+ n = real_to_integer (&c);
+
+ if ((n & 1) == 0)
+ {
+ REAL_VALUE_TYPE cint;
+ real_from_integer (&cint, VOIDmode, n, n < 0 ? -1 : 0, 0);
+ if (real_identical (&c, &cint))
+ return true;
+ }
+ }
+
+ break;
+
+ default:
+ return false;
+ }
+ }
+ }
+
+ return false;
+}
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