- if (TREE_CODE (record_type) != RECORD_TYPE
- && TREE_CODE (record_type) != UNION_TYPE
- && TREE_CODE (record_type) != QUAL_UNION_TYPE)
- return NULL_TREE;
-
- /* Short-circuit silly cases. */
- if (useless_type_conversion_p (record_type, orig_type))
- return NULL_TREE;
-
- tail_array_field = NULL_TREE;
- for (f = TYPE_FIELDS (record_type); f ; f = TREE_CHAIN (f))
- {
- int cmp;
-
- if (TREE_CODE (f) != FIELD_DECL)
- continue;
- if (DECL_BIT_FIELD (f))
- continue;
-
- if (!DECL_FIELD_OFFSET (f))
- continue;
- field_offset = byte_position (f);
- if (TREE_CODE (field_offset) != INTEGER_CST)
- continue;
-
- /* ??? Java creates "interesting" fields for representing base classes.
- They have no name, and have no context. With no context, we get into
- trouble with nonoverlapping_component_refs_p. Skip them. */
- if (!DECL_FIELD_CONTEXT (f))
- continue;
-
- /* The previous array field isn't at the end. */
- tail_array_field = NULL_TREE;
-
- /* Check to see if this offset overlaps with the field. */
- cmp = tree_int_cst_compare (field_offset, offset);
- if (cmp > 0)
- continue;
-
- field_type = TREE_TYPE (f);
-
- /* Here we exactly match the offset being checked. If the types match,
- then we can return that field. */
- if (cmp == 0
- && useless_type_conversion_p (orig_type, field_type))
- {
- if (base_is_ptr)
- base = build1 (INDIRECT_REF, record_type, base);
- t = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
- return t;
- }
-
- /* Don't care about offsets into the middle of scalars. */
- if (!AGGREGATE_TYPE_P (field_type))
- continue;
-
- /* Check for array at the end of the struct. This is often
- used as for flexible array members. We should be able to
- turn this into an array access anyway. */
- if (TREE_CODE (field_type) == ARRAY_TYPE)
- tail_array_field = f;
-
- /* Check the end of the field against the offset. */
- if (!DECL_SIZE_UNIT (f)
- || TREE_CODE (DECL_SIZE_UNIT (f)) != INTEGER_CST)
- continue;
- t = int_const_binop (MINUS_EXPR, offset, field_offset, 1);
- if (!tree_int_cst_lt (t, DECL_SIZE_UNIT (f)))
- continue;
-
- /* If we matched, then set offset to the displacement into
- this field. */
- if (base_is_ptr)
- new_base = build1 (INDIRECT_REF, record_type, base);
- else
- new_base = base;
- protected_set_expr_location (new_base, loc);
- new_base = build3 (COMPONENT_REF, field_type, new_base, f, NULL_TREE);
- protected_set_expr_location (new_base, loc);
-
- /* Recurse to possibly find the match. */
- ret = maybe_fold_offset_to_array_ref (loc, new_base, t, orig_type,
- f == TYPE_FIELDS (record_type));
- if (ret)
- return ret;
- ret = maybe_fold_offset_to_component_ref (loc, field_type, new_base, t,
- orig_type, false);
- if (ret)
- return ret;
- }
-
- if (!tail_array_field)
- return NULL_TREE;
-
- f = tail_array_field;
- field_type = TREE_TYPE (f);
- offset = int_const_binop (MINUS_EXPR, offset, byte_position (f), 1);
-
- /* If we get here, we've got an aggregate field, and a possibly
- nonzero offset into them. Recurse and hope for a valid match. */
- if (base_is_ptr)
- {
- base = build1 (INDIRECT_REF, record_type, base);
- SET_EXPR_LOCATION (base, loc);
- }
- base = build3 (COMPONENT_REF, field_type, base, f, NULL_TREE);
- SET_EXPR_LOCATION (base, loc);
-
- t = maybe_fold_offset_to_array_ref (loc, base, offset, orig_type,
- f == TYPE_FIELDS (record_type));
- if (t)
- return t;
- return maybe_fold_offset_to_component_ref (loc, field_type, base, offset,
- orig_type, false);
-}
-
-/* Attempt to express (ORIG_TYPE)BASE+OFFSET as BASE->field_of_orig_type
- or BASE[index] or by combination of those.
-
- LOC is the location of original expression.
-
- Before attempting the conversion strip off existing ADDR_EXPRs and
- handled component refs. */
-
-tree
-maybe_fold_offset_to_reference (location_t loc, tree base, tree offset,
- tree orig_type)
-{
- tree ret;
- tree type;
- bool base_is_ptr = true;
-
- STRIP_NOPS (base);
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- base_is_ptr = false;
-
- base = TREE_OPERAND (base, 0);
-
- /* Handle case where existing COMPONENT_REF pick e.g. wrong field of union,
- so it needs to be removed and new COMPONENT_REF constructed.
- The wrong COMPONENT_REF are often constructed by folding the
- (type *)&object within the expression (type *)&object+offset */
- if (handled_component_p (base))
- {
- HOST_WIDE_INT sub_offset, size, maxsize;
- tree newbase;
- newbase = get_ref_base_and_extent (base, &sub_offset,
- &size, &maxsize);
- gcc_assert (newbase);
- if (size == maxsize
- && size != -1
- && !(sub_offset & (BITS_PER_UNIT - 1)))
- {
- base = newbase;
- if (sub_offset)
- offset = int_const_binop (PLUS_EXPR, offset,
- build_int_cst (TREE_TYPE (offset),
- sub_offset / BITS_PER_UNIT), 1);
- }
- }
- if (useless_type_conversion_p (orig_type, TREE_TYPE (base))
- && integer_zerop (offset))
- return base;
- type = TREE_TYPE (base);
- }
- else
- {
- base_is_ptr = true;
- if (!POINTER_TYPE_P (TREE_TYPE (base)))
- return NULL_TREE;
- type = TREE_TYPE (TREE_TYPE (base));
- }
- ret = maybe_fold_offset_to_component_ref (loc, type, base, offset,
- orig_type, base_is_ptr);
- if (!ret)
- {
- if (base_is_ptr)
- {
- base = build1 (INDIRECT_REF, type, base);
- SET_EXPR_LOCATION (base, loc);
- }
- ret = maybe_fold_offset_to_array_ref (loc,
- base, offset, orig_type, true);
- }
- return ret;
-}
-
-/* Attempt to express (ORIG_TYPE)&BASE+OFFSET as &BASE->field_of_orig_type
- or &BASE[index] or by combination of those.
-
- LOC is the location of the original expression.
-
- Before attempting the conversion strip off existing component refs. */
-
-tree
-maybe_fold_offset_to_address (location_t loc, tree addr, tree offset,
- tree orig_type)
-{
- tree t;
-
- gcc_assert (POINTER_TYPE_P (TREE_TYPE (addr))
- && POINTER_TYPE_P (orig_type));
-
- t = maybe_fold_offset_to_reference (loc, addr, offset,
- TREE_TYPE (orig_type));
- if (t != NULL_TREE)
- {
- tree orig = addr;
- tree ptr_type;
-
- /* For __builtin_object_size to function correctly we need to
- make sure not to fold address arithmetic so that we change
- reference from one array to another. This would happen for
- example for
-
- struct X { char s1[10]; char s2[10] } s;
- char *foo (void) { return &s.s2[-4]; }
-
- where we need to avoid generating &s.s1[6]. As the C and
- C++ frontends create different initial trees
- (char *) &s.s1 + -4 vs. &s.s1[-4] we have to do some
- sophisticated comparisons here. Note that checking for the
- condition after the fact is easier than trying to avoid doing
- the folding. */
- STRIP_NOPS (orig);
- if (TREE_CODE (orig) == ADDR_EXPR)
- orig = TREE_OPERAND (orig, 0);
- if ((TREE_CODE (orig) == ARRAY_REF
- || (TREE_CODE (orig) == COMPONENT_REF
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (orig, 1))) == ARRAY_TYPE))
- && (TREE_CODE (t) == ARRAY_REF
- || TREE_CODE (t) == COMPONENT_REF)
- && !operand_equal_p (TREE_CODE (orig) == ARRAY_REF
- ? TREE_OPERAND (orig, 0) : orig,
- TREE_CODE (t) == ARRAY_REF
- ? TREE_OPERAND (t, 0) : t, 0))
- return NULL_TREE;
-
- ptr_type = build_pointer_type (TREE_TYPE (t));
- if (!useless_type_conversion_p (orig_type, ptr_type))
- return NULL_TREE;
- return build_fold_addr_expr_with_type_loc (loc, t, ptr_type);
- }
-
- return NULL_TREE;
-}
-
-/* A subroutine of fold_stmt. Attempt to simplify *(BASE+OFFSET).
- Return the simplified expression, or NULL if nothing could be done. */
-
-static tree
-maybe_fold_stmt_indirect (tree expr, tree base, tree offset)
-{
- tree t;
- bool volatile_p = TREE_THIS_VOLATILE (expr);
- location_t loc = EXPR_LOCATION (expr);
-
- /* We may well have constructed a double-nested PLUS_EXPR via multiple
- substitutions. Fold that down to one. Remove NON_LVALUE_EXPRs that
- are sometimes added. */
- base = fold (base);
- STRIP_TYPE_NOPS (base);
- TREE_OPERAND (expr, 0) = base;
-
- /* One possibility is that the address reduces to a string constant. */
- t = fold_read_from_constant_string (expr);
- if (t)
- return t;
-
- /* Add in any offset from a POINTER_PLUS_EXPR. */
- if (TREE_CODE (base) == POINTER_PLUS_EXPR)
- {
- tree offset2;
-
- offset2 = TREE_OPERAND (base, 1);
- if (TREE_CODE (offset2) != INTEGER_CST)
- return NULL_TREE;
- base = TREE_OPERAND (base, 0);
-
- offset = fold_convert (sizetype,
- int_const_binop (PLUS_EXPR, offset, offset2, 1));
- }
-
- if (TREE_CODE (base) == ADDR_EXPR)
- {
- tree base_addr = base;
-
- /* Strip the ADDR_EXPR. */
- base = TREE_OPERAND (base, 0);
-
- /* Fold away CONST_DECL to its value, if the type is scalar. */
- if (TREE_CODE (base) == CONST_DECL
- && is_gimple_min_invariant (DECL_INITIAL (base)))
- return DECL_INITIAL (base);
-
- /* Try folding *(&B+O) to B.X. */
- t = maybe_fold_offset_to_reference (loc, base_addr, offset,
- TREE_TYPE (expr));
- if (t)
- {
- /* Preserve volatileness of the original expression.
- We can end up with a plain decl here which is shared
- and we shouldn't mess with its flags. */
- if (!SSA_VAR_P (t))
- TREE_THIS_VOLATILE (t) = volatile_p;
- return t;
- }
- }
- else
- {
- /* We can get here for out-of-range string constant accesses,
- such as "_"[3]. Bail out of the entire substitution search
- and arrange for the entire statement to be replaced by a
- call to __builtin_trap. In all likelihood this will all be
- constant-folded away, but in the meantime we can't leave with
- something that get_expr_operands can't understand. */
-
- t = base;
- STRIP_NOPS (t);
- if (TREE_CODE (t) == ADDR_EXPR
- && TREE_CODE (TREE_OPERAND (t, 0)) == STRING_CST)
- {
- /* FIXME: Except that this causes problems elsewhere with dead
- code not being deleted, and we die in the rtl expanders
- because we failed to remove some ssa_name. In the meantime,
- just return zero. */
- /* FIXME2: This condition should be signaled by
- fold_read_from_constant_string directly, rather than
- re-checking for it here. */
- return integer_zero_node;
- }
-
- /* Try folding *(B+O) to B->X. Still an improvement. */
- if (POINTER_TYPE_P (TREE_TYPE (base)))
- {
- t = maybe_fold_offset_to_reference (loc, base, offset,
- TREE_TYPE (expr));
- if (t)
- return t;
- }
- }
-
- /* Otherwise we had an offset that we could not simplify. */
- return NULL_TREE;
-}
-
-
-/* A quaint feature extant in our address arithmetic is that there
- can be hidden type changes here. The type of the result need
- not be the same as the type of the input pointer.
-
- What we're after here is an expression of the form
- (T *)(&array + const)
- where array is OP0, const is OP1, RES_TYPE is T and
- the cast doesn't actually exist, but is implicit in the
- type of the POINTER_PLUS_EXPR. We'd like to turn this into
- &array[x]
- which may be able to propagate further. */
-
-tree
-maybe_fold_stmt_addition (location_t loc, tree res_type, tree op0, tree op1)
-{
- tree ptd_type;
- tree t;
-
- /* The first operand should be an ADDR_EXPR. */
- if (TREE_CODE (op0) != ADDR_EXPR)
- return NULL_TREE;
- op0 = TREE_OPERAND (op0, 0);
-
- /* It had better be a constant. */
- if (TREE_CODE (op1) != INTEGER_CST)
- {
- /* Or op0 should now be A[0] and the non-constant offset defined
- via a multiplication by the array element size. */
- if (TREE_CODE (op0) == ARRAY_REF
- && integer_zerop (TREE_OPERAND (op0, 1))
- && TREE_CODE (op1) == SSA_NAME
- && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (op0)), 1))
- {
- gimple offset_def = SSA_NAME_DEF_STMT (op1);
- if (!is_gimple_assign (offset_def))
- return NULL_TREE;
-
- if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
- && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
- && tree_int_cst_equal (gimple_assign_rhs2 (offset_def),
- TYPE_SIZE_UNIT (TREE_TYPE (op0))))
- return build1 (ADDR_EXPR, res_type,
- build4 (ARRAY_REF, TREE_TYPE (op0),
- TREE_OPERAND (op0, 0),
- gimple_assign_rhs1 (offset_def),
- TREE_OPERAND (op0, 2),
- TREE_OPERAND (op0, 3)));
- else if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (op0)))
- && gimple_assign_rhs_code (offset_def) != MULT_EXPR)
- return build1 (ADDR_EXPR, res_type,
- build4 (ARRAY_REF, TREE_TYPE (op0),
- TREE_OPERAND (op0, 0),
- op1,
- TREE_OPERAND (op0, 2),
- TREE_OPERAND (op0, 3)));
- }
- return NULL_TREE;
- }
-
- /* If the first operand is an ARRAY_REF, expand it so that we can fold
- the offset into it. */
- while (TREE_CODE (op0) == ARRAY_REF)
- {
- tree array_obj = TREE_OPERAND (op0, 0);
- tree array_idx = TREE_OPERAND (op0, 1);
- tree elt_type = TREE_TYPE (op0);
- tree elt_size = TYPE_SIZE_UNIT (elt_type);
- tree min_idx;
-
- if (TREE_CODE (array_idx) != INTEGER_CST)
- break;
- if (TREE_CODE (elt_size) != INTEGER_CST)
- break;
-
- /* Un-bias the index by the min index of the array type. */
- min_idx = TYPE_DOMAIN (TREE_TYPE (array_obj));
- if (min_idx)
- {
- min_idx = TYPE_MIN_VALUE (min_idx);
- if (min_idx)
- {
- if (TREE_CODE (min_idx) != INTEGER_CST)
- break;
-
- array_idx = fold_convert (TREE_TYPE (min_idx), array_idx);
- if (!integer_zerop (min_idx))
- array_idx = int_const_binop (MINUS_EXPR, array_idx,
- min_idx, 0);
- }
- }
-
- /* Convert the index to a byte offset. */
- array_idx = fold_convert (sizetype, array_idx);
- array_idx = int_const_binop (MULT_EXPR, array_idx, elt_size, 0);
-
- /* Update the operands for the next round, or for folding. */
- op1 = int_const_binop (PLUS_EXPR,
- array_idx, op1, 0);
- op0 = array_obj;
- }
-
- ptd_type = TREE_TYPE (res_type);
- /* If we want a pointer to void, reconstruct the reference from the
- array element type. A pointer to that can be trivially converted
- to void *. This happens as we fold (void *)(ptr p+ off). */
- if (VOID_TYPE_P (ptd_type)
- && TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
- ptd_type = TREE_TYPE (TREE_TYPE (op0));
-
- /* At which point we can try some of the same things as for indirects. */
- t = maybe_fold_offset_to_array_ref (loc, op0, op1, ptd_type, true);
- if (!t)
- t = maybe_fold_offset_to_component_ref (loc, TREE_TYPE (op0), op0, op1,
- ptd_type, false);
- if (t)
- {
- t = build1 (ADDR_EXPR, res_type, t);
- SET_EXPR_LOCATION (t, loc);
- }
-
- return t;
-}
-
-/* Subroutine of fold_stmt. We perform several simplifications of the
- memory reference tree EXPR and make sure to re-gimplify them properly
- after propagation of constant addresses. IS_LHS is true if the
- reference is supposed to be an lvalue. */
-
-static tree
-maybe_fold_reference (tree expr, bool is_lhs)
-{
- tree *t = &expr;
-
- if (TREE_CODE (expr) == ARRAY_REF
- && !is_lhs)
- {
- tree tem = fold_read_from_constant_string (expr);
- if (tem)
- return tem;
- }
-
- /* ??? We might want to open-code the relevant remaining cases
- to avoid using the generic fold. */
- if (handled_component_p (*t)
- && CONSTANT_CLASS_P (TREE_OPERAND (*t, 0)))
- {
- tree tem = fold (*t);
- if (tem != *t)
- return tem;
- }
-
- while (handled_component_p (*t))
- t = &TREE_OPERAND (*t, 0);
-
- if (TREE_CODE (*t) == INDIRECT_REF)
- {
- tree tem = maybe_fold_stmt_indirect (*t, TREE_OPERAND (*t, 0),
- integer_zero_node);
- /* Avoid folding *"abc" = 5 into 'a' = 5. */
- if (is_lhs && tem && CONSTANT_CLASS_P (tem))
- tem = NULL_TREE;
- if (!tem
- && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR)
- /* If we had a good reason for propagating the address here,
- make sure we end up with valid gimple. See PR34989. */
- tem = TREE_OPERAND (TREE_OPERAND (*t, 0), 0);
-
- if (tem)
- {
- *t = tem;
- tem = maybe_fold_reference (expr, is_lhs);
- if (tem)
- return tem;
- return expr;
- }
- }
-
- return NULL_TREE;
-}
-
-
-/* Return the string length, maximum string length or maximum value of
- ARG in LENGTH.
- If ARG is an SSA name variable, follow its use-def chains. If LENGTH
- is not NULL and, for TYPE == 0, its value is not equal to the length
- we determine or if we are unable to determine the length or value,
- return false. VISITED is a bitmap of visited variables.
- TYPE is 0 if string length should be returned, 1 for maximum string
- length and 2 for maximum value ARG can have. */
-
-static bool
-get_maxval_strlen (tree arg, tree *length, bitmap visited, int type)
-{
- tree var, val;
- gimple def_stmt;
-
- if (TREE_CODE (arg) != SSA_NAME)
- {
- if (TREE_CODE (arg) == COND_EXPR)
- return get_maxval_strlen (COND_EXPR_THEN (arg), length, visited, type)
- && get_maxval_strlen (COND_EXPR_ELSE (arg), length, visited, type);
- /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */
- else if (TREE_CODE (arg) == ADDR_EXPR
- && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF
- && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1)))
- {
- tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0);
- if (TREE_CODE (aop0) == INDIRECT_REF
- && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME)
- return get_maxval_strlen (TREE_OPERAND (aop0, 0),
- length, visited, type);
- }
-
- if (type == 2)
- {
- val = arg;
- if (TREE_CODE (val) != INTEGER_CST
- || tree_int_cst_sgn (val) < 0)
- return false;
- }
- else
- val = c_strlen (arg, 1);
- if (!val)
- return false;
-
- if (*length)
- {
- if (type > 0)
- {
- if (TREE_CODE (*length) != INTEGER_CST
- || TREE_CODE (val) != INTEGER_CST)
- return false;
-
- if (tree_int_cst_lt (*length, val))
- *length = val;
- return true;
- }
- else if (simple_cst_equal (val, *length) != 1)
- return false;
- }
-
- *length = val;
- return true;
- }
-
- /* If we were already here, break the infinite cycle. */
- if (bitmap_bit_p (visited, SSA_NAME_VERSION (arg)))
- return true;
- bitmap_set_bit (visited, SSA_NAME_VERSION (arg));
-
- var = arg;
- def_stmt = SSA_NAME_DEF_STMT (var);
-
- switch (gimple_code (def_stmt))
- {
- case GIMPLE_ASSIGN:
- /* The RHS of the statement defining VAR must either have a
- constant length or come from another SSA_NAME with a constant
- length. */
- if (gimple_assign_single_p (def_stmt)
- || gimple_assign_unary_nop_p (def_stmt))
- {
- tree rhs = gimple_assign_rhs1 (def_stmt);
- return get_maxval_strlen (rhs, length, visited, type);
- }
- return false;
-
- case GIMPLE_PHI:
- {
- /* All the arguments of the PHI node must have the same constant
- length. */
- unsigned i;
-
- for (i = 0; i < gimple_phi_num_args (def_stmt); i++)
- {
- tree arg = gimple_phi_arg (def_stmt, i)->def;
-
- /* If this PHI has itself as an argument, we cannot
- determine the string length of this argument. However,
- if we can find a constant string length for the other
- PHI args then we can still be sure that this is a
- constant string length. So be optimistic and just
- continue with the next argument. */
- if (arg == gimple_phi_result (def_stmt))
- continue;
-
- if (!get_maxval_strlen (arg, length, visited, type))
- return false;
- }
- }
- return true;
-
- default:
- return false;
- }
-}
-
-
-/* Fold builtin call in statement STMT. Returns a simplified tree.
- We may return a non-constant expression, including another call
- to a different function and with different arguments, e.g.,
- substituting memcpy for strcpy when the string length is known.
- Note that some builtins expand into inline code that may not
- be valid in GIMPLE. Callers must take care. */
-
-static tree
-ccp_fold_builtin (gimple stmt)
-{
- tree result, val[3];
- tree callee, a;
- int arg_idx, type;
- bitmap visited;
- bool ignore;
- int nargs;
- location_t loc = gimple_location (stmt);
-
- gcc_assert (is_gimple_call (stmt));
-
- ignore = (gimple_call_lhs (stmt) == NULL);
-
- /* First try the generic builtin folder. If that succeeds, return the
- result directly. */
- result = fold_call_stmt (stmt, ignore);
- if (result)
- {
- if (ignore)
- STRIP_NOPS (result);
- return result;
- }
-
- /* Ignore MD builtins. */
- callee = gimple_call_fndecl (stmt);
- if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD)
- return NULL_TREE;
-
- /* If the builtin could not be folded, and it has no argument list,
- we're done. */
- nargs = gimple_call_num_args (stmt);
- if (nargs == 0)
- return NULL_TREE;
-
- /* Limit the work only for builtins we know how to simplify. */
- switch (DECL_FUNCTION_CODE (callee))
- {
- case BUILT_IN_STRLEN:
- case BUILT_IN_FPUTS:
- case BUILT_IN_FPUTS_UNLOCKED:
- arg_idx = 0;
- type = 0;
- break;
- case BUILT_IN_STRCPY:
- case BUILT_IN_STRNCPY:
- arg_idx = 1;
- type = 0;
- break;
- case BUILT_IN_MEMCPY_CHK:
- case BUILT_IN_MEMPCPY_CHK:
- case BUILT_IN_MEMMOVE_CHK:
- case BUILT_IN_MEMSET_CHK:
- case BUILT_IN_STRNCPY_CHK:
- arg_idx = 2;
- type = 2;
- break;
- case BUILT_IN_STRCPY_CHK:
- case BUILT_IN_STPCPY_CHK:
- arg_idx = 1;
- type = 1;
- break;
- case BUILT_IN_SNPRINTF_CHK:
- case BUILT_IN_VSNPRINTF_CHK:
- arg_idx = 1;
- type = 2;
- break;
- default:
- return NULL_TREE;
- }
-
- if (arg_idx >= nargs)
- return NULL_TREE;
-
- /* Try to use the dataflow information gathered by the CCP process. */
- visited = BITMAP_ALLOC (NULL);
- bitmap_clear (visited);
-
- memset (val, 0, sizeof (val));
- a = gimple_call_arg (stmt, arg_idx);
- if (!get_maxval_strlen (a, &val[arg_idx], visited, type))
- val[arg_idx] = NULL_TREE;
-
- BITMAP_FREE (visited);
-
- result = NULL_TREE;
- switch (DECL_FUNCTION_CODE (callee))
- {
- case BUILT_IN_STRLEN:
- if (val[0] && nargs == 1)
- {
- tree new_val =
- fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]);
-
- /* If the result is not a valid gimple value, or not a cast
- of a valid gimple value, then we can not use the result. */
- if (is_gimple_val (new_val)
- || (is_gimple_cast (new_val)
- && is_gimple_val (TREE_OPERAND (new_val, 0))))
- return new_val;
- }
- break;
-
- case BUILT_IN_STRCPY:
- if (val[1] && is_gimple_val (val[1]) && nargs == 2)
- result = fold_builtin_strcpy (loc, callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- val[1]);
- break;
-
- case BUILT_IN_STRNCPY:
- if (val[1] && is_gimple_val (val[1]) && nargs == 3)
- result = fold_builtin_strncpy (loc, callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- val[1]);
- break;
-
- case BUILT_IN_FPUTS:
- if (nargs == 2)
- result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- ignore, false, val[0]);
- break;
-
- case BUILT_IN_FPUTS_UNLOCKED:
- if (nargs == 2)
- result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- ignore, true, val[0]);
- break;
-
- case BUILT_IN_MEMCPY_CHK:
- case BUILT_IN_MEMPCPY_CHK:
- case BUILT_IN_MEMMOVE_CHK:
- case BUILT_IN_MEMSET_CHK:
- if (val[2] && is_gimple_val (val[2]) && nargs == 4)
- result = fold_builtin_memory_chk (loc, callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- gimple_call_arg (stmt, 3),
- val[2], ignore,
- DECL_FUNCTION_CODE (callee));
- break;
-
- case BUILT_IN_STRCPY_CHK:
- case BUILT_IN_STPCPY_CHK:
- if (val[1] && is_gimple_val (val[1]) && nargs == 3)
- result = fold_builtin_stxcpy_chk (loc, callee,
- gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- val[1], ignore,
- DECL_FUNCTION_CODE (callee));
- break;
-
- case BUILT_IN_STRNCPY_CHK:
- if (val[2] && is_gimple_val (val[2]) && nargs == 4)
- result = fold_builtin_strncpy_chk (loc, gimple_call_arg (stmt, 0),
- gimple_call_arg (stmt, 1),
- gimple_call_arg (stmt, 2),
- gimple_call_arg (stmt, 3),
- val[2]);
- break;
-
- case BUILT_IN_SNPRINTF_CHK:
- case BUILT_IN_VSNPRINTF_CHK:
- if (val[1] && is_gimple_val (val[1]))
- result = gimple_fold_builtin_snprintf_chk (stmt, val[1],
- DECL_FUNCTION_CODE (callee));
- break;
-
- default:
- gcc_unreachable ();
- }
-
- if (result && ignore)
- result = fold_ignored_result (result);
- return result;
-}
-
-/* Attempt to fold an assignment statement pointed-to by SI. Returns a
- replacement rhs for the statement or NULL_TREE if no simplification
- could be made. It is assumed that the operands have been previously
- folded. */
-
-static tree
-fold_gimple_assign (gimple_stmt_iterator *si)
-{
- gimple stmt = gsi_stmt (*si);
- enum tree_code subcode = gimple_assign_rhs_code (stmt);
- location_t loc = gimple_location (stmt);
-
- tree result = NULL_TREE;
-
- switch (get_gimple_rhs_class (subcode))
- {
- case GIMPLE_SINGLE_RHS:
- {
- tree rhs = gimple_assign_rhs1 (stmt);
-
- /* Try to fold a conditional expression. */
- if (TREE_CODE (rhs) == COND_EXPR)
- {
- tree op0 = COND_EXPR_COND (rhs);
- tree tem;
- bool set = false;
- location_t cond_loc = EXPR_LOCATION (rhs);
-
- if (COMPARISON_CLASS_P (op0))
- {
- fold_defer_overflow_warnings ();
- tem = fold_binary_loc (cond_loc,
- TREE_CODE (op0), TREE_TYPE (op0),
- TREE_OPERAND (op0, 0),
- TREE_OPERAND (op0, 1));
- /* This is actually a conditional expression, not a GIMPLE
- conditional statement, however, the valid_gimple_rhs_p
- test still applies. */
- set = (tem && is_gimple_condexpr (tem)
- && valid_gimple_rhs_p (tem));
- fold_undefer_overflow_warnings (set, stmt, 0);
- }
- else if (is_gimple_min_invariant (op0))
- {
- tem = op0;
- set = true;
- }
- else
- return NULL_TREE;
-
- if (set)
- result = fold_build3_loc (cond_loc, COND_EXPR, TREE_TYPE (rhs), tem,
- COND_EXPR_THEN (rhs), COND_EXPR_ELSE (rhs));
- }
-
- else if (TREE_CODE (rhs) == TARGET_MEM_REF)
- return maybe_fold_tmr (rhs);
-
- else if (REFERENCE_CLASS_P (rhs))
- return maybe_fold_reference (rhs, false);