/* This file contains the definitions and documentation for the
tree codes used in GCC.
- Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004
+ Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004, 2005
Free Software Foundation, Inc.
This file is part of GCC.
different structures, and the size is determined by the tree_union
member structure; the 4th element should be zero. Languages that
define language-specific tcc_exceptional or tcc_constant codes must
- define the tree_size langhook to say how big they are. */
+ define the tree_size langhook to say how big they are.
+
+ These tree codes have been sorted so that the macros in tree.h that
+ check for various tree codes are optimized into range checks. This
+ gives a measurable performance improvement. When adding a new
+ code, consider its placement in relation to the other codes. */
/* Any erroneous construct is parsed into a node of this type.
This type of node is accepted without complaint in all contexts
ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
see below. */
-DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0)
- /* The void type in C */
-
-/* Integer types in all languages, including char in C.
- Also used for sub-ranges of other discrete types.
- Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
- and TYPE_PRECISION (number of bits used by this type).
- In the case of a subrange type in Pascal, the TREE_TYPE
- of this will point at the supertype (another INTEGER_TYPE,
- or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
- Otherwise, the TREE_TYPE is zero. */
-DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0)
-
-/* C's float and double. Different floating types are distinguished
- by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
-DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0)
-
-/* Complex number types. The TREE_TYPE field is the data type
- of the real and imaginary parts. */
-DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0)
-
-/* Vector types. The TREE_TYPE field is the data type of the vector
- elements. The TYPE_PRECISION field is the number of subparts of
- the vector. */
-DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0)
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, CHAR_TYPE,
+ INTEGER_TYPE, REAL_TYPE, POINTER_TYPE. */
+
+/* An offset is a pointer relative to an object.
+ The TREE_TYPE field is the type of the object at the offset.
+ The TYPE_OFFSET_BASETYPE points to the node for the type of object
+ that the offset is relative to. */
+DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0)
/* C enums. The type node looks just like an INTEGER_TYPE node.
The symbols for the values of the enum type are defined by
treated similarly. */
DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0)
-/* Pascal's boolean type (true or false are the only values);
- no special fields needed. */
+/* Boolean type (true or false are the only values). Looks like an
+ INTEGRAL_TYPE. */
DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0)
-/* CHAR in Pascal; not used in C.
- No special fields needed. */
+/* CHAR in Java; not used in C. Looks like an INTEGRAL_TYPE. */
DEFTREECODE (CHAR_TYPE, "char_type", tcc_type, 0)
+/* Integer types in all languages, including char in C.
+ Also used for sub-ranges of other discrete types.
+ Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
+ and TYPE_PRECISION (number of bits used by this type).
+ In the case of a subrange type in Pascal, the TREE_TYPE
+ of this will point at the supertype (another INTEGER_TYPE,
+ or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
+ Otherwise, the TREE_TYPE is zero. */
+DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0)
+
+/* C's float and double. Different floating types are distinguished
+ by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
+DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0)
+
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. POINTER_TYPE, REFERENCE_TYPE. Note that this range
+ overlaps the previous range of ordered types. */
+
/* All pointer-to-x types have code POINTER_TYPE.
The TREE_TYPE points to the node for the type pointed to. */
DEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0)
-/* An offset is a pointer relative to an object.
- The TREE_TYPE field is the type of the object at the offset.
- The TYPE_OFFSET_BASETYPE points to the node for the type of object
- that the offset is relative to. */
-DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0)
-
/* A reference is like a pointer except that it is coerced
automatically to the value it points to. Used in C++. */
DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0)
-/* METHOD_TYPE is the type of a function which takes an extra first
- argument for "self", which is not present in the declared argument list.
- The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
- is the type of "self". TYPE_ARG_TYPES is the real argument list, which
- includes the hidden argument for "self". */
-DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0)
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE. */
+
+/* Complex number types. The TREE_TYPE field is the data type
+ of the real and imaginary parts. */
+DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0)
-/* Used for Pascal; details not determined right now. */
-DEFTREECODE (FILE_TYPE, "file_type", tcc_type, 0)
+/* Vector types. The TREE_TYPE field is the data type of the vector
+ elements. The TYPE_PRECISION field is the number of subparts of
+ the vector. */
+DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0)
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE.
+ Note that this range overlaps the previous range. */
+
/* Types of arrays. Special fields:
TREE_TYPE Type of an array element.
TYPE_DOMAIN Type to index by.
the union. */
DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0)
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE. */
+
+/* The void type in C */
+DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0)
+
/* Type of functions. Special fields:
TREE_TYPE type of value returned.
TYPE_ARG_TYPES list of types of arguments expected.
have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
DEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0)
+/* METHOD_TYPE is the type of a function which takes an extra first
+ argument for "self", which is not present in the declared argument list.
+ The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
+ is the type of "self". TYPE_ARG_TYPES is the real argument list, which
+ includes the hidden argument for "self". */
+DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0)
+
/* This is a language-specific kind of type.
Its meaning is defined by the language front end.
layout_type does not know how to lay this out,
DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0)
DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0)
-DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0)
-DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0)
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL,
+ TYPE_DECL. */
+DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0)
DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0)
+DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0)
DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0)
+DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0)
DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0)
-DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0)
/* A namespace declaration. Namespaces appear in DECL_CONTEXT of other
_DECLs, providing a hierarchy of names. */
BIT_FIELD_REF_UNSIGNED says which. */
DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3)
+/* The ordering of the following codes is optimized for the checking
+ macros in tree.h. Changing the order will degrade the speed of the
+ compiler. INDIRECT_REF, ALIGN_INDIRECT_REF, MISALIGNED_INDIRECT_REF. */
+
/* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */
DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1)
have VOID_TYPE. The same constraints apply to operand 2. */
DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3)
-/* Vector conditional expresion. It is like COND_EXPR, but with
+/* Vector conditional expression. It is like COND_EXPR, but with
vector operands.
A = VEC_COND_EXPR ( X < Y, B, C)
/* Unary negation. */
DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1)
+/* Minimum and maximum values. When used with floating point, if both
+ operands are zeros, or if either operand is NaN, then it is unspecified
+ which of the two operands is returned as the result. */
DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2)
DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2)
The second operand is the number of bits to
shift by; it need not be the same type as the first operand and result.
Note that the result is undefined if the second operand is larger
- than the first operand's type size. */
+ than or equal to the first operand's type size. */
DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2)
DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2)
DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2)
PHI_ARG_ELT returns the Ith tuple <ssa_name, edge> from the
argument list. Each tuple contains the incoming reaching
definition (SSA_NAME node) and the edge via which that definition
- is coming through. */
+ is coming through. */
DEFTREECODE (PHI_NODE, "phi_node", tcc_exceptional, 0)
/* Used to represent a typed exception handler. CATCH_TYPES is the type (or