#include "expr.h"
#include "lex.h"
#include "toplev.h"
+#include "output.h"
/* forward declarations */
static int chill_l_equivalent PROTO((tree, tree, struct mode_chain*));
}
}
\f
-/* Return nonzero if VALUE is a valid constant-valued expression
- for use in initializing a static variable; one that can be an
- element of a "constant" initializer.
-
- Return null_pointer_node if the value is absolute;
- if it is relocatable, return the variable that determines the relocation.
- We assume that VALUE has been folded as much as possible;
- therefore, we do not need to check for such things as
- arithmetic-combinations of integers. */
-
-tree
-initializer_constant_valid_p (value, endtype)
- tree value;
- tree endtype;
-{
- switch (TREE_CODE (value))
- {
- case CONSTRUCTOR:
- if (TREE_CODE (TREE_TYPE (value)) == UNION_TYPE
- && TREE_CONSTANT (value))
- return
- initializer_constant_valid_p (TREE_VALUE (CONSTRUCTOR_ELTS (value)),
- endtype);
-
- return TREE_STATIC (value) ? null_pointer_node : 0;
-
- case INTEGER_CST:
- case REAL_CST:
- case STRING_CST:
- case COMPLEX_CST:
- return null_pointer_node;
-
- case ADDR_EXPR:
- return TREE_OPERAND (value, 0);
-
- case NON_LVALUE_EXPR:
- return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
-
- case CONVERT_EXPR:
- case NOP_EXPR:
- /* Allow conversions between pointer types. */
- if (TREE_CODE (TREE_TYPE (value)) == POINTER_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == POINTER_TYPE)
- return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
-
- /* Allow conversions between real types. */
- if (TREE_CODE (TREE_TYPE (value)) == REAL_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == REAL_TYPE)
- return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
-
- /* Allow length-preserving conversions between integer types. */
- if (TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == INTEGER_TYPE
- && (TYPE_PRECISION (TREE_TYPE (value))
- == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
- return initializer_constant_valid_p (TREE_OPERAND (value, 0), endtype);
-
- /* Allow conversions between other integer types only if
- explicit value. */
- if (TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == INTEGER_TYPE)
- {
- tree inner = initializer_constant_valid_p (TREE_OPERAND (value, 0),
- endtype);
- if (inner == null_pointer_node)
- return null_pointer_node;
- return 0;
- }
-
- /* Allow (int) &foo provided int is as wide as a pointer. */
- if (TREE_CODE (TREE_TYPE (value)) == INTEGER_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == POINTER_TYPE
- && (TYPE_PRECISION (TREE_TYPE (value))
- >= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
- return initializer_constant_valid_p (TREE_OPERAND (value, 0),
- endtype);
-
- /* Likewise conversions from int to pointers. */
- if (TREE_CODE (TREE_TYPE (value)) == POINTER_TYPE
- && TREE_CODE (TREE_TYPE (TREE_OPERAND (value, 0))) == INTEGER_TYPE
- && (TYPE_PRECISION (TREE_TYPE (value))
- <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (value, 0)))))
- return initializer_constant_valid_p (TREE_OPERAND (value, 0),
- endtype);
-
- /* Allow conversions to union types if the value inside is okay. */
- if (TREE_CODE (TREE_TYPE (value)) == UNION_TYPE)
- return initializer_constant_valid_p (TREE_OPERAND (value, 0),
- endtype);
- return 0;
-
- case PLUS_EXPR:
- if (TREE_CODE (endtype) == INTEGER_TYPE
- && TYPE_PRECISION (endtype) < POINTER_SIZE)
- return 0;
- {
- tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
- endtype);
- tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
- endtype);
- /* If either term is absolute, use the other terms relocation. */
- if (valid0 == null_pointer_node)
- return valid1;
- if (valid1 == null_pointer_node)
- return valid0;
- return 0;
- }
-
- case MINUS_EXPR:
- if (TREE_CODE (endtype) == INTEGER_TYPE
- && TYPE_PRECISION (endtype) < POINTER_SIZE)
- return 0;
- {
- tree valid0 = initializer_constant_valid_p (TREE_OPERAND (value, 0),
- endtype);
- tree valid1 = initializer_constant_valid_p (TREE_OPERAND (value, 1),
- endtype);
- /* Win if second argument is absolute. */
- if (valid1 == null_pointer_node)
- return valid0;
- /* Win if both arguments have the same relocation.
- Then the value is absolute. */
- if (valid0 == valid1)
- return null_pointer_node;
- return 0;
- }
- default:
- return 0;
- }
-}
-\f
/* Return an integer type with BITS bits of precision,
that is unsigned if UNSIGNEDP is nonzero, otherwise signed. */