/* This file contains the definitions and documentation for the
- tree codes used in the GNU C compiler.
+ tree codes used in GCC.
Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001
Free Software Foundation, Inc.
'<' for codes for comparison expressions.
'1' for codes for unary arithmetic expressions.
'2' for codes for binary arithmetic expressions.
- 's' for codes for expressions with inherent side effects.
+ 's' for codes for "statement" expressions, which have side-effects,
+ but usually no interesting value.
'e' for codes for other kinds of expressions. */
-/* For `r', `e', `<', `1', `2', `s' and `x' nodes,
- the 4th element is the number of argument slots to allocate.
- This determines the size of the tree node object. */
+/* For `r', `e', `<', `1', `2', and `s' nodes, which use struct
+ tree_exp, the 4th element is the number of argument slots to
+ allocate. This determines the size of the tree node object.
+ Other nodes use different structures, and the size is determined
+ by the tree_union member structure; the 4th element should be
+ zero. Languages that define language-specific 'x' or 'c' codes
+ must define the tree_size langhook to say how big they are. */
/* Any erroneous construct is parsed into a node of this type.
This type of node is accepted without complaint in all contexts
Internally it looks like a STRING_CST node.
There is only one IDENTIFIER_NODE ever made for any particular name.
Use `get_identifier' to get it (or create it, the first time). */
-DEFTREECODE (IDENTIFIER_NODE, "identifier_node", 'x', -1)
+DEFTREECODE (IDENTIFIER_NODE, "identifier_node", 'x', 0)
/* Has the TREE_VALUE and TREE_PURPOSE fields. */
/* These nodes are made into lists by chaining through the
TREE_CHAIN field. The elements of the list live in the
TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
used as well to get the effect of Lisp association lists. */
-DEFTREECODE (TREE_LIST, "tree_list", 'x', 2)
+DEFTREECODE (TREE_LIST, "tree_list", 'x', 0)
/* These nodes contain an array of tree nodes. */
-DEFTREECODE (TREE_VEC, "tree_vec", 'x', 2)
+DEFTREECODE (TREE_VEC, "tree_vec", 'x', 0)
/* A symbol binding block. These are arranged in a tree,
where the BLOCK_SUBBLOCKS field contains a chain of subblocks
could either point to another BLOCK node or it could point to a
FUNCTION_DECL node (e.g. in the case of a block representing the
outermost scope of a particular inlining of a function).
- BLOCK_ABSTRACT is non-zero if the block represents an abstract
+ BLOCK_ABSTRACT is nonzero if the block represents an abstract
instance of a block (i.e. one which is nested within an abstract
instance of an inline function).
- TREE_ASM_WRITTEN is non-zero if the block was actually referenced
+ TREE_ASM_WRITTEN is nonzero if the block was actually referenced
in the generated assembly. */
DEFTREECODE (BLOCK, "block", 'b', 0)
\f
TREE_TYPE Type of an array element.
TYPE_DOMAIN Type to index by.
Its range of values specifies the array length.
- TYPE_SEP Expression for units from one elt to the next.
- TYPE_SEP_UNIT Number of bits in a unit for previous.
The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
and holds the type to coerce a value of that array type to in C.
TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
- in languages (such as Chill) that make a distinction. */
+ in languages (such as Chill) that make a distinction. */
/* Array types in C or Pascal */
DEFTREECODE (ARRAY_TYPE, "array_type", 't', 0)
/* Types of sets for Pascal. Special fields are the same as
in an array type. The target type is always a boolean type.
Used for both bitstrings and powersets in Chill;
- TYPE_STRING_FLAG indicates a bitstring. */
+ TYPE_STRING_FLAG indicates a bitstring. */
DEFTREECODE (SET_TYPE, "set_type", 't', 0)
/* Struct in C, or record in Pascal. */
Note: constants of type char in Pascal are INTEGER_CST,
and so are pointer constants such as nil in Pascal or NULL in C.
`(int *) 1' in C also results in an INTEGER_CST. */
-DEFTREECODE (INTEGER_CST, "integer_cst", 'c', 2)
+DEFTREECODE (INTEGER_CST, "integer_cst", 'c', 0)
-/* Contents are in TREE_REAL_CST field. Also there is TREE_CST_RTL. */
-DEFTREECODE (REAL_CST, "real_cst", 'c', 3)
+/* Contents are in TREE_REAL_CST field. */
+DEFTREECODE (REAL_CST, "real_cst", 'c', 0)
/* Contents are in TREE_REALPART and TREE_IMAGPART fields,
- whose contents are other constant nodes.
- Also there is TREE_CST_RTL. */
-DEFTREECODE (COMPLEX_CST, "complex_cst", 'c', 3)
+ whose contents are other constant nodes. */
+DEFTREECODE (COMPLEX_CST, "complex_cst", 'c', 0)
-/* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields.
- Also there is TREE_CST_RTL. */
-DEFTREECODE (STRING_CST, "string_cst", 'c', 3)
+/* Contents are in TREE_VECTOR_CST_ELTS field. */
+DEFTREECODE (VECTOR_CST, "vector_cst", 'c', 0)
+
+/* Contents are TREE_STRING_LENGTH and TREE_STRING_POINTER fields. */
+DEFTREECODE (STRING_CST, "string_cst", 'c', 0)
/* Declarations. All references to names are represented as ..._DECL nodes.
The decls in one binding context are chained through the TREE_CHAIN field.
holds a line number. In some cases these can be the location of
a reference, if no definition has been seen.
- DECL_ABSTRACT is non-zero if the decl represents an abstract instance
+ DECL_ABSTRACT is nonzero if the decl represents an abstract instance
of a decl (i.e. one which is nested within an abstract instance of a
inline function. */
DEFTREECODE (BUFFER_REF, "buffer_ref", 'r', 1)
/* Array indexing.
- Operand 0 is the array; operand 1 is a (single) array index. */
+ Operand 0 is the array; operand 1 is a (single) array index. */
DEFTREECODE (ARRAY_REF, "array_ref", 'r', 2)
/* Likewise, except that the result is a range ("slice") of the array. The
of the range is taken from the type of the expression. */
DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", 'r', 2)
+/* Vtable indexing. Carries data useful for emitting information
+ for vtable garbage collection.
+ Operand 0: an array_ref (or equivalent expression)
+ Operand 1: the vtable base (must be a var_decl)
+ Operand 2: index into vtable (must be an integer_cst). */
+DEFTREECODE (VTABLE_REF, "vtable_ref", 'r', 3)
+
/* Constructor: return an aggregate value made from specified components.
In C, this is used only for structure and array initializers.
Also used for SET_TYPE in Chill (and potentially Pascal).
- The first "operand" is really a pointer to the RTL,
- for constant constructors only.
- The second operand is a list of component values
- made out of a chain of TREE_LIST nodes.
+ The operand is a list of component values made out of a chain of
+ TREE_LIST nodes.
For ARRAY_TYPE:
The TREE_PURPOSE of each node is the corresponding index.
The TREE_VALUE specifies a value (index) in the set that is true.
If TREE_PURPOSE is non-NULL, it specifies the lower limit of a
range of true values. Elements not listed are false (not in the set). */
-DEFTREECODE (CONSTRUCTOR, "constructor", 'e', 2)
+DEFTREECODE (CONSTRUCTOR, "constructor", 'e', 1)
/* The expression types are mostly straightforward, with the fourth argument
of DEFTREECODE saying how many operands there are.
operand of the ABS_EXPR must have the same type. */
DEFTREECODE (ABS_EXPR, "abs_expr", '1', 1)
+/* Bit scanning and counting. */
DEFTREECODE (FFS_EXPR, "ffs_expr", '1', 1)
+DEFTREECODE (CLZ_EXPR, "clz_expr", '1', 1)
+DEFTREECODE (CTZ_EXPR, "ctz_expr", '1', 1)
+DEFTREECODE (POPCOUNT_EXPR, "popcount_expr", '1', 1)
+DEFTREECODE (PARITY_EXPR, "parity_expr", '1', 1)
/* Shift operations for shift and rotate.
Shift means logical shift if done on an
needed or not (for side effects). The operand may have
BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be
either zero or one. For example, a TRUTH_NOT_EXPR will never have
- a INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
+ an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
used to compare the VAR_DECL to zero, thereby obtaining a node with
value zero or one. */
DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", 'e', 2)
DEFTREECODE (UNORDERED_EXPR, "unordered_expr", '<', 2)
DEFTREECODE (ORDERED_EXPR, "ordered_expr", '<', 2)
-/* These are equivalent to unordered or ... */
+/* These are equivalent to unordered or ... */
DEFTREECODE (UNLT_EXPR, "unlt_expr", '<', 2)
DEFTREECODE (UNLE_EXPR, "unle_expr", '<', 2)
DEFTREECODE (UNGT_EXPR, "ungt_expr", '<', 2)
/* Value is same as argument, but guaranteed not an lvalue. */
DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", '1', 1)
+/* Represents viewing something of one type as being of a second type.
+ This corresponds to an "Unchecked Conversion" in Ada and roughly to
+ the idiom *(type2 *)&X in C. The only operand is the value to be
+ viewed as being of another type. It is undefined if the type of the
+ input and of the expression have different sizes.
+
+ This code may also be used within the LHS of a MODIFY_EXPR, in which
+ case no actual data motion may occur. TREE_ADDRESSABLE will be set in
+ this case and GCC must abort if it could not do the operation without
+ generating insns. */
+DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", '1', 1)
+
/* Represents something we computed once and will use multiple times.
First operand is that expression. Second is the function decl
in which the SAVE_EXPR was created. The third operand is the RTL,
DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", 'e', 2)
/* Evaluate the first operand.
- The second operand is a a cleanup expression which is evaluated
- before an exit (normal, exception, or jump out) from this expression.
-
- Like a CLEANUP_POINT_EXPR/WITH_CLEANUP_EXPR combination, but those
- always copy the cleanup expression where needed. In contrast,
- TRY_FINALLY_EXPR generates a jump to a cleanup subroutine.
- (At least conceptually; the optimizer could inline the cleanup
- subroutine in the same way it could inline normal subroutines.)
- TRY_FINALLY_EXPR should be used when the cleanup is actual statements
- in the source of the current function (which people might want to
- set breakpoints in). */
+ The second operand is a cleanup expression which is evaluated
+ on any exit (normal, exception, or jump out) from this expression. */
DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", 'e', 2)
/* Used internally for cleanups in the implementation of TRY_FINALLY_EXPR.
/* Switch expression.
Operand 0 is the expression used to perform the branch,
Operand 1 contains the case values. The way they're organized is
- front-end implementation defined. */
+ front-end implementation defined. */
DEFTREECODE (SWITCH_EXPR, "switch_expr", 'e', 2)
/* The exception object from the runtime. */