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[official-gcc/Ramakrishna.git] / gcc / tree.def
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1 /* This file contains the definitions and documentation for the
2 tree codes used in GCC.
3 Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004, 2005,
4 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* For tcc_references, tcc_expression, tcc_comparison, tcc_unary,
24 tcc_binary, and tcc_statement nodes, which use struct tree_exp, the
25 4th element is the number of argument slots to allocate. This
26 determines the size of the tree node object. Other nodes use
27 different structures, and the size is determined by the tree_union
28 member structure; the 4th element should be zero. Languages that
29 define language-specific tcc_exceptional or tcc_constant codes must
30 define the tree_size langhook to say how big they are.
32 These tree codes have been sorted so that the macros in tree.h that
33 check for various tree codes are optimized into range checks. This
34 gives a measurable performance improvement. When adding a new
35 code, consider its placement in relation to the other codes. */
37 /* Any erroneous construct is parsed into a node of this type.
38 This type of node is accepted without complaint in all contexts
39 by later parsing activities, to avoid multiple error messages
40 for one error.
41 No fields in these nodes are used except the TREE_CODE. */
42 DEFTREECODE (ERROR_MARK, "error_mark", tcc_exceptional, 0)
44 /* Used to represent a name (such as, in the DECL_NAME of a decl node).
45 Internally it looks like a STRING_CST node.
46 There is only one IDENTIFIER_NODE ever made for any particular name.
47 Use `get_identifier' to get it (or create it, the first time). */
48 DEFTREECODE (IDENTIFIER_NODE, "identifier_node", tcc_exceptional, 0)
50 /* Has the TREE_VALUE and TREE_PURPOSE fields. */
51 /* These nodes are made into lists by chaining through the
52 TREE_CHAIN field. The elements of the list live in the
53 TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
54 used as well to get the effect of Lisp association lists. */
55 DEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0)
57 /* These nodes contain an array of tree nodes. */
58 DEFTREECODE (TREE_VEC, "tree_vec", tcc_exceptional, 0)
60 /* A symbol binding block. These are arranged in a tree,
61 where the BLOCK_SUBBLOCKS field contains a chain of subblocks
62 chained through the BLOCK_CHAIN field.
63 BLOCK_SUPERCONTEXT points to the parent block.
64 For a block which represents the outermost scope of a function, it
65 points to the FUNCTION_DECL node.
66 BLOCK_VARS points to a chain of decl nodes.
67 BLOCK_CHAIN points to the next BLOCK at the same level.
68 BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which
69 this block is an instance of, or else is NULL to indicate that this
70 block is not an instance of anything else. When non-NULL, the value
71 could either point to another BLOCK node or it could point to a
72 FUNCTION_DECL node (e.g. in the case of a block representing the
73 outermost scope of a particular inlining of a function).
74 BLOCK_ABSTRACT is nonzero if the block represents an abstract
75 instance of a block (i.e. one which is nested within an abstract
76 instance of an inline function).
77 TREE_ASM_WRITTEN is nonzero if the block was actually referenced
78 in the generated assembly. */
79 DEFTREECODE (BLOCK, "block", tcc_exceptional, 0)
81 /* Each data type is represented by a tree node whose code is one of
82 the following: */
83 /* Each node that represents a data type has a component TYPE_SIZE
84 containing a tree that is an expression for the size in bits.
85 The TYPE_MODE contains the machine mode for values of this type.
86 The TYPE_POINTER_TO field contains a type for a pointer to this type,
87 or zero if no such has been created yet.
88 The TYPE_NEXT_VARIANT field is used to chain together types
89 that are variants made by type modifiers such as "const" and "volatile".
90 The TYPE_MAIN_VARIANT field, in any member of such a chain,
91 points to the start of the chain.
92 The TYPE_NAME field contains info on the name used in the program
93 for this type (for GDB symbol table output). It is either a
94 TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
95 in the case of structs, unions or enums that are known with a tag,
96 or zero for types that have no special name.
97 The TYPE_CONTEXT for any sort of type which could have a name or
98 which could have named members (e.g. tagged types in C/C++) will
99 point to the node which represents the scope of the given type, or
100 will be NULL_TREE if the type has "file scope". For most types, this
101 will point to a BLOCK node or a FUNCTION_DECL node, but it could also
102 point to a FUNCTION_TYPE node (for types whose scope is limited to the
103 formal parameter list of some function type specification) or it
104 could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node
105 (for C++ "member" types).
106 For non-tagged-types, TYPE_CONTEXT need not be set to anything in
107 particular, since any type which is of some type category (e.g.
108 an array type or a function type) which cannot either have a name
109 itself or have named members doesn't really have a "scope" per se.
110 The TREE_CHAIN field is used as a forward-references to names for
111 ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
112 see below. */
114 /* The ordering of the following codes is optimized for the checking
115 macros in tree.h. Changing the order will degrade the speed of the
116 compiler. OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, INTEGER_TYPE,
117 REAL_TYPE, POINTER_TYPE. */
119 /* An offset is a pointer relative to an object.
120 The TREE_TYPE field is the type of the object at the offset.
121 The TYPE_OFFSET_BASETYPE points to the node for the type of object
122 that the offset is relative to. */
123 DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0)
125 /* C enums. The type node looks just like an INTEGER_TYPE node.
126 The symbols for the values of the enum type are defined by
127 CONST_DECL nodes, but the type does not point to them;
128 however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE
129 is a name and the TREE_VALUE is the value (an INTEGER_CST node). */
130 /* A forward reference `enum foo' when no enum named foo is defined yet
131 has zero (a null pointer) in its TYPE_SIZE. The tag name is in
132 the TYPE_NAME field. If the type is later defined, the normal
133 fields are filled in.
134 RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are
135 treated similarly. */
136 DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0)
138 /* Boolean type (true or false are the only values). Looks like an
139 INTEGRAL_TYPE. */
140 DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0)
142 /* Integer types in all languages, including char in C.
143 Also used for sub-ranges of other discrete types.
144 Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
145 and TYPE_PRECISION (number of bits used by this type).
146 In the case of a subrange type in Pascal, the TREE_TYPE
147 of this will point at the supertype (another INTEGER_TYPE,
148 or an ENUMERAL_TYPE or BOOLEAN_TYPE).
149 Otherwise, the TREE_TYPE is zero. */
150 DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0)
152 /* C's float and double. Different floating types are distinguished
153 by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
154 DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0)
156 /* The ordering of the following codes is optimized for the checking
157 macros in tree.h. Changing the order will degrade the speed of the
158 compiler. POINTER_TYPE, REFERENCE_TYPE. Note that this range
159 overlaps the previous range of ordered types. */
161 /* All pointer-to-x types have code POINTER_TYPE.
162 The TREE_TYPE points to the node for the type pointed to. */
163 DEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0)
165 /* _Fract and _Accum types in Embedded-C. Different fixed-point types
166 are distinguished by machine mode and by the TYPE_SIZE and the
167 TYPE_PRECISION. */
168 DEFTREECODE (FIXED_POINT_TYPE, "fixed_point_type", tcc_type, 0)
170 /* A reference is like a pointer except that it is coerced
171 automatically to the value it points to. Used in C++. */
172 DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0)
174 /* The ordering of the following codes is optimized for the checking
175 macros in tree.h. Changing the order will degrade the speed of the
176 compiler. COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE. */
178 /* Complex number types. The TREE_TYPE field is the data type
179 of the real and imaginary parts. It must be of scalar
180 arithmetic type, not including pointer type. */
181 DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0)
183 /* Vector types. The TREE_TYPE field is the data type of the vector
184 elements. The TYPE_PRECISION field is the number of subparts of
185 the vector. */
186 DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0)
188 /* The ordering of the following codes is optimized for the checking
189 macros in tree.h. Changing the order will degrade the speed of the
190 compiler. ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE.
191 Note that this range overlaps the previous range. */
193 /* Types of arrays. Special fields:
194 TREE_TYPE Type of an array element.
195 TYPE_DOMAIN Type to index by.
196 Its range of values specifies the array length.
197 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
198 and holds the type to coerce a value of that array type to in C.
199 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
200 in languages (such as Chill) that make a distinction. */
201 /* Array types in C or Pascal */
202 DEFTREECODE (ARRAY_TYPE, "array_type", tcc_type, 0)
204 /* Struct in C, or record in Pascal. */
205 /* Special fields:
206 TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct,
207 and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables,
208 types and enumerators.
209 A few may need to be added for Pascal. */
210 /* See the comment above, before ENUMERAL_TYPE, for how
211 forward references to struct tags are handled in C. */
212 DEFTREECODE (RECORD_TYPE, "record_type", tcc_type, 0)
214 /* Union in C. Like a struct, except that the offsets of the fields
215 will all be zero. */
216 /* See the comment above, before ENUMERAL_TYPE, for how
217 forward references to union tags are handled in C. */
218 DEFTREECODE (UNION_TYPE, "union_type", tcc_type, 0) /* C union type */
220 /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
221 in each FIELD_DECL determine what the union contains. The first
222 field whose DECL_QUALIFIER expression is true is deemed to occupy
223 the union. */
224 DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0)
226 /* The ordering of the following codes is optimized for the checking
227 macros in tree.h. Changing the order will degrade the speed of the
228 compiler. VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE. */
230 /* The void type in C */
231 DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0)
233 /* Type of functions. Special fields:
234 TREE_TYPE type of value returned.
235 TYPE_ARG_TYPES list of types of arguments expected.
236 this list is made of TREE_LIST nodes.
237 Types of "Procedures" in languages where they are different from functions
238 have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
239 DEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0)
241 /* METHOD_TYPE is the type of a function which takes an extra first
242 argument for "self", which is not present in the declared argument list.
243 The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
244 is the type of "self". TYPE_ARG_TYPES is the real argument list, which
245 includes the hidden argument for "self". */
246 DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0)
248 /* This is a language-specific kind of type.
249 Its meaning is defined by the language front end.
250 layout_type does not know how to lay this out,
251 so the front-end must do so manually. */
252 DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0)
254 /* Expressions */
256 /* First, the constants. */
258 /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
259 32 bits each, giving us a 64 bit constant capability. INTEGER_CST
260 nodes can be shared, and therefore should be considered read only.
261 They should be copied, before setting a flag such as TREE_OVERFLOW.
262 If an INTEGER_CST has TREE_OVERFLOW already set, it is known to be unique.
263 INTEGER_CST nodes are created for the integral types, for pointer
264 types and for vector and float types in some circumstances. */
265 DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0)
267 /* Contents are in TREE_REAL_CST field. */
268 DEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0)
270 /* Contents are in TREE_FIXED_CST field. */
271 DEFTREECODE (FIXED_CST, "fixed_cst", tcc_constant, 0)
273 /* Contents are in TREE_REALPART and TREE_IMAGPART fields,
274 whose contents are other constant nodes. */
275 DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0)
277 /* Contents are in TREE_VECTOR_CST_ELTS field. */
278 DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0)
280 /* Contents are TREE_STRING_LENGTH and the actual contents of the string. */
281 DEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0)
283 /* Declarations. All references to names are represented as ..._DECL
284 nodes. The decls in one binding context are chained through the
285 TREE_CHAIN field. Each DECL has a DECL_NAME field which contains
286 an IDENTIFIER_NODE. (Some decls, most often labels, may have zero
287 as the DECL_NAME). DECL_CONTEXT points to the node representing
288 the context in which this declaration has its scope. For
289 FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or
290 QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL,
291 PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this
292 points to either the FUNCTION_DECL for the containing function, the
293 RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or
294 a TRANSLATION_UNIT_DECL if the given decl has "file scope".
295 DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
296 ..._DECL node of which this decl is an (inlined or template expanded)
297 instance.
298 The TREE_TYPE field holds the data type of the object, when relevant.
299 LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field
300 contents are the type whose name is being declared.
301 The DECL_ALIGN, DECL_SIZE,
302 and DECL_MODE fields exist in decl nodes just as in type nodes.
303 They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
305 DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for
306 the location. DECL_VOFFSET holds an expression for a variable
307 offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer).
308 These fields are relevant only in FIELD_DECLs and PARM_DECLs.
310 DECL_INITIAL holds the value to initialize a variable to,
311 or the value of a constant. For a function, it holds the body
312 (a node of type BLOCK representing the function's binding contour
313 and whose body contains the function's statements.) For a LABEL_DECL
314 in C, it is a flag, nonzero if the label's definition has been seen.
316 PARM_DECLs use a special field:
317 DECL_ARG_TYPE is the type in which the argument is actually
318 passed, which may be different from its type within the function.
320 FUNCTION_DECLs use four special fields:
321 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
322 DECL_RESULT holds a RESULT_DECL node for the value of a function.
323 The DECL_RTL field is 0 for a function that returns no value.
324 (C functions returning void have zero here.)
325 The TREE_TYPE field is the type in which the result is actually
326 returned. This is usually the same as the return type of the
327 FUNCTION_DECL, but it may be a wider integer type because of
328 promotion.
329 DECL_FUNCTION_CODE is a code number that is nonzero for
330 built-in functions. Its value is an enum built_in_function
331 that says which built-in function it is.
333 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
334 holds a line number. In some cases these can be the location of
335 a reference, if no definition has been seen.
337 DECL_ABSTRACT is nonzero if the decl represents an abstract instance
338 of a decl (i.e. one which is nested within an abstract instance of a
339 inline function. */
341 DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0)
342 DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0)
343 /* The ordering of the following codes is optimized for the checking
344 macros in tree.h. Changing the order will degrade the speed of the
345 compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL,
346 TYPE_DECL. */
347 DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0)
348 DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0)
349 DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0)
350 DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0)
351 DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0)
352 DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0)
354 /* A namespace declaration. Namespaces appear in DECL_CONTEXT of other
355 _DECLs, providing a hierarchy of names. */
356 DEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0)
358 /* A declaration import.
359 The C++ FE uses this to represent a using-directive; eg:
360 "using namespace foo".
361 But it could be used to represent any declaration import construct.
362 Whenever a declaration import appears in a lexical block, the BLOCK node
363 representing that lexical block in GIMPLE will contain an IMPORTED_DECL
364 node, linked via BLOCK_VARS accessor of the said BLOCK.
365 For a given NODE which code is IMPORTED_DECL,
366 IMPORTED_DECL_ASSOCIATED_DECL (NODE) accesses the imported declaration. */
367 DEFTREECODE (IMPORTED_DECL, "imported_decl", tcc_declaration, 0)
369 /* A translation unit. This is not technically a declaration, since it
370 can't be looked up, but it's close enough. */
371 DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\
372 tcc_declaration, 0)
374 /* References to storage. */
376 /* The ordering of the following codes is optimized for the classification
377 in handled_component_p. Keep them in a consecutive group. */
379 /* Value is structure or union component.
380 Operand 0 is the structure or union (an expression).
381 Operand 1 is the field (a node of type FIELD_DECL).
382 Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured
383 in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT. */
384 DEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3)
386 /* Reference to a group of bits within an object. Similar to COMPONENT_REF
387 except the position is given explicitly rather than via a FIELD_DECL.
388 Operand 0 is the structure or union expression;
389 operand 1 is a tree giving the constant number of bits being referenced;
390 operand 2 is a tree giving the constant position of the first referenced bit.
391 The result type width has to match the number of bits referenced.
392 If the result type is integral, its signedness specifies how it is extended
393 to its mode width. */
394 DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3)
396 /* Used only on an operand of complex type, these return
397 a value of the corresponding component type. */
398 DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1)
399 DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1)
401 /* Array indexing.
402 Operand 0 is the array; operand 1 is a (single) array index.
403 Operand 2, if present, is a copy of TYPE_MIN_VALUE of the index.
404 Operand 3, if present, is the element size, measured in units of
405 the alignment of the element type. */
406 DEFTREECODE (ARRAY_REF, "array_ref", tcc_reference, 4)
408 /* Likewise, except that the result is a range ("slice") of the array. The
409 starting index of the resulting array is taken from operand 1 and the size
410 of the range is taken from the type of the expression. */
411 DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4)
413 /* The ordering of the following codes is optimized for the checking
414 macros in tree.h. Changing the order will degrade the speed of the
415 compiler. INDIRECT_REF, ALIGN_INDIRECT_REF, MISALIGNED_INDIRECT_REF. */
417 /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */
418 DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1)
420 /* Like above, but aligns the referenced address (i.e, if the address
421 in P is not aligned on TYPE_ALIGN boundary, then &(*P) != P). */
422 DEFTREECODE (ALIGN_INDIRECT_REF, "align_indirect_ref", tcc_reference, 1)
424 /* Same as INDIRECT_REF, but also specifies the alignment of the referenced
425 address:
426 Operand 0 is the referenced address (a pointer);
427 Operand 1 is an INTEGER_CST which represents the alignment of the address,
428 or 0 if the alignment is unknown. */
429 DEFTREECODE (MISALIGNED_INDIRECT_REF, "misaligned_indirect_ref", tcc_reference, 2)
431 /* Used to represent lookup of runtime type dependent data. Often this is
432 a reference to a vtable, but it needn't be. Operands are:
433 OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use.
434 OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is
435 being performed. Through this the optimizers may be able to statically
436 determine the dynamic type of the object.
437 OBJ_TYPE_REF_TOKEN: Something front-end specific used to resolve the
438 reference to something simpler, usually to the address of a DECL.
439 Never touched by the middle-end. Good choices would be either an
440 identifier or a vtable index. */
441 DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3)
443 /* The exception object from the runtime. */
444 DEFTREECODE (EXC_PTR_EXPR, "exc_ptr_expr", tcc_expression, 0)
446 /* The filter object from the runtime. */
447 DEFTREECODE (FILTER_EXPR, "filter_expr", tcc_expression, 0)
449 /* Constructor: return an aggregate value made from specified components.
450 In C, this is used only for structure and array initializers.
451 The operand is a sequence of component values made out of a VEC of
452 struct constructor_elt.
454 For ARRAY_TYPE:
455 The field INDEX of each constructor_elt is the corresponding index.
456 If the index is a RANGE_EXPR, it is a short-hand for many nodes,
457 one for each index in the range. (If the corresponding field VALUE
458 has side-effects, they are evaluated once for each element. Wrap the
459 value in a SAVE_EXPR if you want to evaluate side effects only once.)
461 For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE:
462 The field INDEX of each node is a FIELD_DECL. */
463 DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0)
465 /* The expression types are mostly straightforward, with the fourth argument
466 of DEFTREECODE saying how many operands there are.
467 Unless otherwise specified, the operands are expressions and the
468 types of all the operands and the expression must all be the same. */
470 /* Contains two expressions to compute, one followed by the other.
471 the first value is ignored. The second one's value is used. The
472 type of the first expression need not agree with the other types. */
473 DEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2)
475 /* Assignment expression. Operand 0 is the what to set; 1, the new value. */
476 DEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2)
478 /* Initialization expression. Operand 0 is the variable to initialize;
479 Operand 1 is the initializer. This differs from MODIFY_EXPR in that any
480 reference to the referent of operand 0 within operand 1 is undefined. */
481 DEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2)
483 /* For TARGET_EXPR, operand 0 is the target of an initialization,
484 operand 1 is the initializer for the target, which may be void
485 if simply expanding it initializes the target.
486 operand 2 is the cleanup for this node, if any.
487 operand 3 is the saved initializer after this node has been
488 expanded once; this is so we can re-expand the tree later. */
489 DEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4)
491 /* Conditional expression ( ... ? ... : ... in C).
492 Operand 0 is the condition.
493 Operand 1 is the then-value.
494 Operand 2 is the else-value.
495 Operand 0 may be of any type.
496 Operand 1 must have the same type as the entire expression, unless
497 it unconditionally throws an exception, in which case it should
498 have VOID_TYPE. The same constraints apply to operand 2. The
499 condition in operand 0 must be of integral type.
501 In cfg gimple, if you do not have a selection expression, operands
502 1 and 2 are NULL. The operands are then taken from the cfg edges. */
503 DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3)
505 /* Vector conditional expression. It is like COND_EXPR, but with
506 vector operands.
508 A = VEC_COND_EXPR ( X < Y, B, C)
510 means
512 for (i=0; i<N; i++)
513 A[i] = X[i] < Y[i] ? B[i] : C[i];
515 DEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3)
517 /* Declare local variables, including making RTL and allocating space.
518 BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables.
519 BIND_EXPR_BODY is the body, the expression to be computed using
520 the variables. The value of operand 1 becomes that of the BIND_EXPR.
521 BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings
522 for debugging purposes. If this BIND_EXPR is actually expanded,
523 that sets the TREE_USED flag in the BLOCK.
525 The BIND_EXPR is not responsible for informing parsers
526 about these variables. If the body is coming from the input file,
527 then the code that creates the BIND_EXPR is also responsible for
528 informing the parser of the variables.
530 If the BIND_EXPR is ever expanded, its TREE_USED flag is set.
531 This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
532 If the BIND_EXPR should be output for debugging but will not be expanded,
533 set the TREE_USED flag by hand.
535 In order for the BIND_EXPR to be known at all, the code that creates it
536 must also install it as a subblock in the tree of BLOCK
537 nodes for the function. */
538 DEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3)
540 /* Function call. CALL_EXPRs are represented by variably-sized expression
541 nodes. There are at least three fixed operands. Operand 0 is an
542 INTEGER_CST node containing the total operand count, the number of
543 arguments plus 3. Operand 1 is the function, while operand 2 is
544 is static chain argument, or NULL. The remaining operands are the
545 arguments to the call. */
546 DEFTREECODE (CALL_EXPR, "call_expr", tcc_vl_exp, 3)
548 /* Specify a value to compute along with its corresponding cleanup.
549 Operand 0 is the cleanup expression.
550 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR,
551 which must exist. This differs from TRY_CATCH_EXPR in that operand 1
552 is always evaluated when cleanups are run. */
553 DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1)
555 /* Specify a cleanup point.
556 Operand 0 is an expression that may have cleanups. If it does, those
557 cleanups are executed after the expression is expanded.
559 Note that if the expression is a reference to storage, it is forced out
560 of memory before the cleanups are run. This is necessary to handle
561 cases where the cleanups modify the storage referenced; in the
562 expression 't.i', if 't' is a struct with an integer member 'i' and a
563 cleanup which modifies 'i', the value of the expression depends on
564 whether the cleanup is run before or after 't.i' is evaluated. When
565 expand_expr is run on 't.i', it returns a MEM. This is not good enough;
566 the value of 't.i' must be forced out of memory.
568 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
569 BLKmode, because it will not be forced out of memory. */
570 DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1)
572 /* The following two codes are used in languages that have types where
573 some field in an object of the type contains a value that is used in
574 the computation of another field's offset or size and/or the size of
575 the type. The positions and/or sizes of fields can vary from object
576 to object of the same type or even for one and the same object within
577 its scope.
579 Record types with discriminants in Ada or schema types in Pascal are
580 examples of such types. This mechanism is also used to create "fat
581 pointers" for unconstrained array types in Ada; the fat pointer is a
582 structure one of whose fields is a pointer to the actual array type
583 and the other field is a pointer to a template, which is a structure
584 containing the bounds of the array. The bounds in the type pointed
585 to by the first field in the fat pointer refer to the values in the
586 template.
588 When you wish to construct such a type you need "self-references"
589 that allow you to reference the object having this type from the
590 TYPE node, i.e. without having a variable instantiating this type.
592 Such a "self-references" is done using a PLACEHOLDER_EXPR. This is
593 a node that will later be replaced with the object being referenced.
594 Its type is that of the object and selects which object to use from
595 a chain of references (see below). No other slots are used in the
596 PLACEHOLDER_EXPR.
598 For example, if your type FOO is a RECORD_TYPE with a field BAR,
599 and you need the value of <variable>.BAR to calculate TYPE_SIZE
600 (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR
601 whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with
602 the PLACEHOLDER_EXPR as the first operand (which has the correct
603 type). Later, when the size is needed in the program, the back-end
604 will find this PLACEHOLDER_EXPR and generate code to calculate the
605 actual size at run-time. In the following, we describe how this
606 calculation is done.
608 When we wish to evaluate a size or offset, we check whether it contains a
609 PLACEHOLDER_EXPR. If it does, we call substitute_placeholder_in_expr
610 passing both that tree and an expression within which the object may be
611 found. The latter expression is the object itself in the simple case of
612 an Ada record with discriminant, but it can be the array in the case of an
613 unconstrained array.
615 In the latter case, we need the fat pointer, because the bounds of
616 the array can only be accessed from it. However, we rely here on the
617 fact that the expression for the array contains the dereference of
618 the fat pointer that obtained the array pointer. */
620 /* Denotes a record to later be substituted before evaluating this expression.
621 The type of this expression is used to find the record to replace it. */
622 DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0)
624 /* Simple arithmetic. */
625 DEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2)
626 DEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2)
627 DEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2)
629 /* Pointer addition. The first operand is always a pointer and the
630 second operand is an integer of type sizetype. */
631 DEFTREECODE (POINTER_PLUS_EXPR, "pointer_plus_expr", tcc_binary, 2)
633 /* Division for integer result that rounds the quotient toward zero. */
634 DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2)
636 /* Division for integer result that rounds the quotient toward infinity. */
637 DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2)
639 /* Division for integer result that rounds toward minus infinity. */
640 DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2)
642 /* Division for integer result that rounds toward nearest integer. */
643 DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2)
645 /* Four kinds of remainder that go with the four kinds of division. */
646 DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2)
647 DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2)
648 DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2)
649 DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2)
651 /* Division for real result. */
652 DEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2)
654 /* Division which is not supposed to need rounding.
655 Used for pointer subtraction in C. */
656 DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2)
658 /* Conversion of real to fixed point by truncation. */
659 DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1)
661 /* Conversion of an integer to a real. */
662 DEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1)
664 /* Unary negation. */
665 DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1)
667 /* Minimum and maximum values. When used with floating point, if both
668 operands are zeros, or if either operand is NaN, then it is unspecified
669 which of the two operands is returned as the result. */
670 DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2)
671 DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2)
673 /* Represents the absolute value of the operand.
675 An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The
676 operand of the ABS_EXPR must have the same type. */
677 DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1)
679 /* Shift operations for shift and rotate.
680 Shift means logical shift if done on an
681 unsigned type, arithmetic shift if done on a signed type.
682 The second operand is the number of bits to
683 shift by; it need not be the same type as the first operand and result.
684 Note that the result is undefined if the second operand is larger
685 than or equal to the first operand's type size.
687 The first operand of a shift can have either an integer or a
688 (non-integer) fixed-point type. We follow the ISO/IEC TR 18037:2004
689 semantics for the latter.
691 Rotates are defined for integer types only. */
692 DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2)
693 DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2)
694 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2)
695 DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2)
697 /* Bitwise operations. Operands have same mode as result. */
698 DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2)
699 DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2)
700 DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2)
701 DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1)
703 /* ANDIF and ORIF allow the second operand not to be computed if the
704 value of the expression is determined from the first operand. AND,
705 OR, and XOR always compute the second operand whether its value is
706 needed or not (for side effects). The operand may have
707 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be
708 either zero or one. For example, a TRUTH_NOT_EXPR will never have
709 an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
710 used to compare the VAR_DECL to zero, thereby obtaining a node with
711 value zero or one. */
712 DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2)
713 DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2)
714 DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2)
715 DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2)
716 DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2)
717 DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1)
719 /* Relational operators.
720 `EQ_EXPR' and `NE_EXPR' are allowed for any types.
721 The others are allowed only for integer (or pointer or enumeral)
722 or real types.
723 In all cases the operands will have the same type,
724 and the value is always the type used by the language for booleans. */
725 DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2)
726 DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2)
727 DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2)
728 DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2)
729 DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2)
730 DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2)
732 /* Additional relational operators for floating point unordered. */
733 DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2)
734 DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2)
736 /* These are equivalent to unordered or ... */
737 DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2)
738 DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2)
739 DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2)
740 DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2)
741 DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2)
743 /* This is the reverse of uneq_expr. */
744 DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2)
746 DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2)
748 /* Represents a re-association barrier for floating point expressions
749 like explicit parenthesis in fortran. */
750 DEFTREECODE (PAREN_EXPR, "paren_expr", tcc_unary, 1)
752 /* Represents a conversion of type of a value.
753 All conversions, including implicit ones, must be
754 represented by CONVERT_EXPR or NOP_EXPR nodes. */
755 DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1)
757 /* Conversion of a fixed-point value to an integer, a real, or a fixed-point
758 value. Or conversion of a fixed-point value from an integer, a real, or
759 a fixed-point value. */
760 DEFTREECODE (FIXED_CONVERT_EXPR, "fixed_convert_expr", tcc_unary, 1)
762 /* Represents a conversion expected to require no code to be generated. */
763 DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1)
765 /* Value is same as argument, but guaranteed not an lvalue. */
766 DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1)
768 /* Represents viewing something of one type as being of a second type.
769 This corresponds to an "Unchecked Conversion" in Ada and roughly to
770 the idiom *(type2 *)&X in C. The only operand is the value to be
771 viewed as being of another type. It is undefined if the type of the
772 input and of the expression have different sizes.
774 This code may also be used within the LHS of a MODIFY_EXPR, in which
775 case no actual data motion may occur. TREE_ADDRESSABLE will be set in
776 this case and GCC must abort if it could not do the operation without
777 generating insns. */
778 DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1)
780 /* A COMPOUND_LITERAL_EXPR represents a literal that is placed in a DECL. The
781 COMPOUND_LITERAL_EXPR_DECL_EXPR is the a DECL_EXPR containing the decl
782 for the anonymous object represented by the COMPOUND_LITERAL;
783 the DECL_INITIAL of that decl is the CONSTRUCTOR that initializes
784 the compound literal. */
785 DEFTREECODE (COMPOUND_LITERAL_EXPR, "compound_literal_expr", tcc_expression, 1)
787 /* Represents something we computed once and will use multiple times.
788 First operand is that expression. After it is evaluated once, it
789 will be replaced by the temporary variable that holds the value. */
790 DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1)
792 /* & in C. Value is the address at which the operand's value resides.
793 Operand may have any mode. Result mode is Pmode. */
794 DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1)
796 /* Operand0 is a function constant; result is part N of a function
797 descriptor of type ptr_mode. */
798 DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2)
800 /* Given two real or integer operands of the same type,
801 returns a complex value of the corresponding complex type. */
802 DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2)
804 /* Complex conjugate of operand. Used only on complex types. */
805 DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1)
807 /* Nodes for ++ and -- in C.
808 The second arg is how much to increment or decrement by.
809 For a pointer, it would be the size of the object pointed to. */
810 DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2)
811 DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2)
812 DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2)
813 DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2)
815 /* Used to implement `va_arg'. */
816 DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1)
818 /* Evaluate operand 1. If and only if an exception is thrown during
819 the evaluation of operand 1, evaluate operand 2.
821 This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated
822 on a normal or jump exit, only on an exception. */
823 DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2)
825 /* Evaluate the first operand.
826 The second operand is a cleanup expression which is evaluated
827 on any exit (normal, exception, or jump out) from this expression. */
828 DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2)
830 /* These types of expressions have no useful value,
831 and always have side effects. */
833 /* Used to represent a local declaration. The operand is DECL_EXPR_DECL. */
834 DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1)
836 /* A label definition, encapsulated as a statement.
837 Operand 0 is the LABEL_DECL node for the label that appears here.
838 The type should be void and the value should be ignored. */
839 DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1)
841 /* GOTO. Operand 0 is a LABEL_DECL node or an expression.
842 The type should be void and the value should be ignored. */
843 DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1)
845 /* RETURN. Evaluates operand 0, then returns from the current function.
846 Presumably that operand is an assignment that stores into the
847 RESULT_DECL that hold the value to be returned.
848 The operand may be null.
849 The type should be void and the value should be ignored. */
850 DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1)
852 /* Exit the inner most loop conditionally. Operand 0 is the condition.
853 The type should be void and the value should be ignored. */
854 DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1)
856 /* A loop. Operand 0 is the body of the loop.
857 It must contain an EXIT_EXPR or is an infinite loop.
858 The type should be void and the value should be ignored. */
859 DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1)
861 /* Switch expression.
863 TREE_TYPE is the original type of the condition, before any
864 language required type conversions. It may be NULL, in which case
865 the original type and final types are assumed to be the same.
867 Operand 0 is the expression used to perform the branch,
868 Operand 1 is the body of the switch, which probably contains
869 CASE_LABEL_EXPRs. It may also be NULL, in which case operand 2
870 must not be NULL.
871 Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs
872 of all the cases. */
873 DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3)
875 /* Used to represent a case label. The operands are CASE_LOW and
876 CASE_HIGH, respectively. If CASE_LOW is NULL_TREE, the label is a
877 'default' label. If CASE_HIGH is NULL_TREE, the label is a normal case
878 label. CASE_LABEL is the corresponding LABEL_DECL. */
879 DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 3)
881 /* RESX. Resume execution after an exception. Operand 0 is a
882 number indicating the exception region that is being left. */
883 DEFTREECODE (RESX_EXPR, "resx_expr", tcc_statement, 1)
885 /* Used to represent an inline assembly statement. ASM_STRING returns a
886 STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS,
887 ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers
888 for the statement. */
889 DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 4)
891 /* Variable references for SSA analysis. New SSA names are created every
892 time a variable is assigned a new value. The SSA builder uses SSA_NAME
893 nodes to implement SSA versioning. */
894 DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0)
896 /* Used to represent a typed exception handler. CATCH_TYPES is the type (or
897 list of types) handled, and CATCH_BODY is the code for the handler. */
898 DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2)
900 /* Used to represent an exception specification. EH_FILTER_TYPES is a list
901 of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on
902 failure. EH_FILTER_MUST_NOT_THROW controls which range type to use when
903 expanding. */
904 DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2)
906 /* Node used for describing a property that is known at compile
907 time. */
908 DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0)
910 /* Node used for describing a property that is not known at compile
911 time. */
912 DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0)
914 /* Polynomial chains of recurrences.
915 Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}. */
916 DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3)
918 /* Used to chain children of container statements together.
919 Use the interface in tree-iterator.h to access this node. */
920 DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0)
922 /* Predicate assertion. Artificial expression generated by the optimizers
923 to keep track of predicate values. This expression may only appear on
924 the RHS of assignments.
926 Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer
927 two things:
929 1- X is a copy of Y.
930 2- EXPR is a conditional expression and is known to be true.
932 Valid and to be expected forms of conditional expressions are
933 valid GIMPLE conditional expressions (as defined by is_gimple_condexpr)
934 and conditional expressions with the first operand being a
935 PLUS_EXPR with a variable possibly wrapped in a NOP_EXPR first
936 operand and an integer constant second operand.
938 The type of the expression is the same as Y. */
939 DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2)
941 /* Base class information. Holds information about a class as a
942 baseclass of itself or another class. */
943 DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0)
945 /* Records the size for an expression of variable size type. This is
946 for use in contexts in which we are accessing the entire object,
947 such as for a function call, or block copy.
948 Operand 0 is the real expression.
949 Operand 1 is the size of the type in the expression. */
950 DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2)
952 /* Extract elements from two input vectors Operand 0 and Operand 1
953 size VS, according to the offset OFF defined by Operand 2 as
954 follows:
955 If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to
956 the first OFF elements of the vector OP1.
957 If OFF == 0, then the returned vector is OP1.
958 On different targets OFF may take different forms; It can be an address, in
959 which case its low log2(VS)-1 bits define the offset, or it can be a mask
960 generated by the builtin targetm.vectorize.mask_for_load_builtin_decl. */
961 DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3)
963 /* Low-level memory addressing. Operands are SYMBOL (static or global
964 variable), BASE (register), INDEX (register), STEP (integer constant),
965 OFFSET (integer constant). Corresponding address is
966 SYMBOL + BASE + STEP * INDEX + OFFSET. Only variations and values valid on
967 the target are allowed.
969 The type of STEP, INDEX and OFFSET is sizetype. The type of BASE is
970 sizetype or a pointer type (if SYMBOL is NULL).
972 The sixth argument is the reference to the original memory access, which
973 is preserved for the purposes of the RTL alias analysis. */
975 DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 6)
977 /* The ordering of the codes between OMP_PARALLEL and OMP_CRITICAL is
978 exposed to TREE_RANGE_CHECK. */
979 /* OpenMP - #pragma omp parallel [clause1 ... clauseN]
980 Operand 0: OMP_PARALLEL_BODY: Code to be executed by all threads.
981 Operand 1: OMP_PARALLEL_CLAUSES: List of clauses. */
983 DEFTREECODE (OMP_PARALLEL, "omp_parallel", tcc_statement, 2)
985 /* OpenMP - #pragma omp task [clause1 ... clauseN]
986 Operand 0: OMP_TASK_BODY: Code to be executed by all threads.
987 Operand 1: OMP_TASK_CLAUSES: List of clauses. */
989 DEFTREECODE (OMP_TASK, "omp_task", tcc_statement, 2)
991 /* OpenMP - #pragma omp for [clause1 ... clauseN]
992 Operand 0: OMP_FOR_BODY: Loop body.
993 Operand 1: OMP_FOR_CLAUSES: List of clauses.
994 Operand 2: OMP_FOR_INIT: Initialization code of the form
995 VAR = N1.
996 Operand 3: OMP_FOR_COND: Loop conditional expression of the form
997 VAR { <, >, <=, >= } N2.
998 Operand 4: OMP_FOR_INCR: Loop index increment of the form
999 VAR { +=, -= } INCR.
1000 Operand 5: OMP_FOR_PRE_BODY: Filled by the gimplifier with things
1001 from INIT, COND, and INCR that are technically part of the
1002 OMP_FOR structured block, but are evaluated before the loop
1003 body begins.
1005 VAR must be an integer or pointer variable, which is implicitly thread
1006 private. N1, N2 and INCR are required to be loop invariant integer
1007 expressions that are evaluated without any synchronization.
1008 The evaluation order, frequency of evaluation and side-effects are
1009 unspecified by the standard. */
1010 DEFTREECODE (OMP_FOR, "omp_for", tcc_statement, 6)
1012 /* OpenMP - #pragma omp sections [clause1 ... clauseN]
1013 Operand 0: OMP_SECTIONS_BODY: Sections body.
1014 Operand 1: OMP_SECTIONS_CLAUSES: List of clauses. */
1015 DEFTREECODE (OMP_SECTIONS, "omp_sections", tcc_statement, 2)
1017 /* OpenMP - #pragma omp single
1018 Operand 0: OMP_SINGLE_BODY: Single section body.
1019 Operand 1: OMP_SINGLE_CLAUSES: List of clauses. */
1020 DEFTREECODE (OMP_SINGLE, "omp_single", tcc_statement, 2)
1022 /* OpenMP - #pragma omp section
1023 Operand 0: OMP_SECTION_BODY: Section body. */
1024 DEFTREECODE (OMP_SECTION, "omp_section", tcc_statement, 1)
1026 /* OpenMP - #pragma omp master
1027 Operand 0: OMP_MASTER_BODY: Master section body. */
1028 DEFTREECODE (OMP_MASTER, "omp_master", tcc_statement, 1)
1030 /* OpenMP - #pragma omp ordered
1031 Operand 0: OMP_ORDERED_BODY: Master section body. */
1032 DEFTREECODE (OMP_ORDERED, "omp_ordered", tcc_statement, 1)
1034 /* OpenMP - #pragma omp critical [name]
1035 Operand 0: OMP_CRITICAL_BODY: Critical section body.
1036 Operand 1: OMP_CRITICAL_NAME: Identifier for critical section. */
1037 DEFTREECODE (OMP_CRITICAL, "omp_critical", tcc_statement, 2)
1039 /* OpenMP - #pragma omp atomic
1040 Operand 0: The address at which the atomic operation is to be performed.
1041 This address should be stabilized with save_expr.
1042 Operand 1: The expression to evaluate. When the old value of the object
1043 at the address is used in the expression, it should appear as if
1044 build_fold_indirect_ref of the address. */
1045 DEFTREECODE (OMP_ATOMIC, "omp_atomic", tcc_statement, 2)
1047 /* OpenMP clauses. */
1048 DEFTREECODE (OMP_CLAUSE, "omp_clause", tcc_exceptional, 0)
1050 /* Reduction operations.
1051 Operations that take a vector of elements and "reduce" it to a scalar
1052 result (e.g. summing the elements of the vector, finding the minimum over
1053 the vector elements, etc).
1054 Operand 0 is a vector; the first element in the vector has the result.
1055 Operand 1 is a vector. */
1056 DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1)
1057 DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1)
1058 DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1)
1060 /* Widening dot-product.
1061 The first two arguments are of type t1.
1062 The third argument and the result are of type t2, such that t2 is at least
1063 twice the size of t1. DOT_PROD_EXPR(arg1,arg2,arg3) is equivalent to:
1064 tmp = WIDEN_MULT_EXPR(arg1, arg2);
1065 arg3 = PLUS_EXPR (tmp, arg3);
1066 or:
1067 tmp = WIDEN_MULT_EXPR(arg1, arg2);
1068 arg3 = WIDEN_SUM_EXPR (tmp, arg3); */
1069 DEFTREECODE (DOT_PROD_EXPR, "dot_prod_expr", tcc_expression, 3)
1071 /* Widening summation.
1072 The first argument is of type t1.
1073 The second argument is of type t2, such that t2 is at least twice
1074 the size of t1. The type of the entire expression is also t2.
1075 WIDEN_SUM_EXPR is equivalent to first widening (promoting)
1076 the first argument from type t1 to type t2, and then summing it
1077 with the second argument. */
1078 DEFTREECODE (WIDEN_SUM_EXPR, "widen_sum_expr", tcc_binary, 2)
1080 /* Widening multiplication.
1081 The two arguments are of type t1.
1082 The result is of type t2, such that t2 is at least twice
1083 the size of t1. WIDEN_MULT_EXPR is equivalent to first widening (promoting)
1084 the arguments from type t1 to type t2, and then multiplying them. */
1085 DEFTREECODE (WIDEN_MULT_EXPR, "widen_mult_expr", tcc_binary, 2)
1087 /* Whole vector left/right shift in bits.
1088 Operand 0 is a vector to be shifted.
1089 Operand 1 is an integer shift amount in bits. */
1090 DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2)
1091 DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2)
1093 /* Widening vector multiplication.
1094 The two operands are vectors with N elements of size S. Multiplying the
1095 elements of the two vectors will result in N products of size 2*S.
1096 VEC_WIDEN_MULT_HI_EXPR computes the N/2 high products.
1097 VEC_WIDEN_MULT_LO_EXPR computes the N/2 low products. */
1098 DEFTREECODE (VEC_WIDEN_MULT_HI_EXPR, "widen_mult_hi_expr", tcc_binary, 2)
1099 DEFTREECODE (VEC_WIDEN_MULT_LO_EXPR, "widen_mult_lo_expr", tcc_binary, 2)
1101 /* Unpack (extract and promote/widen) the high/low elements of the input
1102 vector into the output vector. The input vector has twice as many
1103 elements as the output vector, that are half the size of the elements
1104 of the output vector. This is used to support type promotion. */
1105 DEFTREECODE (VEC_UNPACK_HI_EXPR, "vec_unpack_hi_expr", tcc_unary, 1)
1106 DEFTREECODE (VEC_UNPACK_LO_EXPR, "vec_unpack_lo_expr", tcc_unary, 1)
1108 /* Unpack (extract) the high/low elements of the input vector, convert
1109 fixed point values to floating point and widen elements into the
1110 output vector. The input vector has twice as many elements as the output
1111 vector, that are half the size of the elements of the output vector. */
1112 DEFTREECODE (VEC_UNPACK_FLOAT_HI_EXPR, "vec_unpack_float_hi_expr", tcc_unary, 1)
1113 DEFTREECODE (VEC_UNPACK_FLOAT_LO_EXPR, "vec_unpack_float_lo_expr", tcc_unary, 1)
1115 /* Pack (demote/narrow and merge) the elements of the two input vectors
1116 into the output vector using truncation/saturation.
1117 The elements of the input vectors are twice the size of the elements of the
1118 output vector. This is used to support type demotion. */
1119 DEFTREECODE (VEC_PACK_TRUNC_EXPR, "vec_pack_trunc_expr", tcc_binary, 2)
1120 DEFTREECODE (VEC_PACK_SAT_EXPR, "vec_pack_sat_expr", tcc_binary, 2)
1122 /* Convert floating point values of the two input vectors to integer
1123 and pack (narrow and merge) the elements into the output vector. The
1124 elements of the input vector are twice the size of the elements of
1125 the output vector. */
1126 DEFTREECODE (VEC_PACK_FIX_TRUNC_EXPR, "vec_pack_fix_trunc_expr", tcc_binary, 2)
1128 /* Extract even/odd fields from vectors. */
1129 DEFTREECODE (VEC_EXTRACT_EVEN_EXPR, "vec_extracteven_expr", tcc_binary, 2)
1130 DEFTREECODE (VEC_EXTRACT_ODD_EXPR, "vec_extractodd_expr", tcc_binary, 2)
1132 /* Merge input vectors interleaving their fields. */
1133 DEFTREECODE (VEC_INTERLEAVE_HIGH_EXPR, "vec_interleavehigh_expr", tcc_binary, 2)
1134 DEFTREECODE (VEC_INTERLEAVE_LOW_EXPR, "vec_interleavelow_expr", tcc_binary, 2)
1136 /* PREDICT_EXPR. Specify hint for branch prediction. The
1137 PREDICT_EXPR_PREDICTOR specify predictor and PREDICT_EXPR_OUTCOME the
1138 outcome (0 for not taken and 1 for taken). Once the profile is guessed
1139 all conditional branches leading to execution paths executing the
1140 PREDICT_EXPR will get predicted by the specified predictor. */
1141 DEFTREECODE (PREDICT_EXPR, "predict_expr", tcc_expression, 1)
1143 /* OPTIMIZATION_NODE. Node to store the optimization options. */
1144 DEFTREECODE (OPTIMIZATION_NODE, "optimization_node", tcc_exceptional, 0)
1146 /* TARGET_OPTION_NODE. Node to store the target specific options. */
1147 DEFTREECODE (TARGET_OPTION_NODE, "target_option_node", tcc_exceptional, 0)
1150 Local variables:
1151 mode:c
1152 End: