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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 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
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 2, or (at your option) any later
11 version.
12
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.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
22
23
24 /* For tcc_references, tcc_expression, tcc_comparison, tcc_unary,
25 tcc_binary, and tcc_statement nodes, which use struct tree_exp, the
26 4th element is the number of argument slots to allocate. This
27 determines the size of the tree node object. Other nodes use
28 different structures, and the size is determined by the tree_union
29 member structure; the 4th element should be zero. Languages that
30 define language-specific tcc_exceptional or tcc_constant codes must
31 define the tree_size langhook to say how big they are.
32
33 These tree codes have been sorted so that the macros in tree.h that
34 check for various tree codes are optimized into range checks. This
35 gives a measurable performance improvement. When adding a new
36 code, consider its placement in relation to the other codes. */
37
38 /* Any erroneous construct is parsed into a node of this type.
39 This type of node is accepted without complaint in all contexts
40 by later parsing activities, to avoid multiple error messages
41 for one error.
42 No fields in these nodes are used except the TREE_CODE. */
43 DEFTREECODE (ERROR_MARK, "error_mark", tcc_exceptional, 0)
44
45 /* Used to represent a name (such as, in the DECL_NAME of a decl node).
46 Internally it looks like a STRING_CST node.
47 There is only one IDENTIFIER_NODE ever made for any particular name.
48 Use `get_identifier' to get it (or create it, the first time). */
49 DEFTREECODE (IDENTIFIER_NODE, "identifier_node", tcc_exceptional, 0)
50
51 /* Has the TREE_VALUE and TREE_PURPOSE fields. */
52 /* These nodes are made into lists by chaining through the
53 TREE_CHAIN field. The elements of the list live in the
54 TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
55 used as well to get the effect of Lisp association lists. */
56 DEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0)
57
58 /* These nodes contain an array of tree nodes. */
59 DEFTREECODE (TREE_VEC, "tree_vec", tcc_exceptional, 0)
60
61 /* A symbol binding block. These are arranged in a tree,
62 where the BLOCK_SUBBLOCKS field contains a chain of subblocks
63 chained through the BLOCK_CHAIN field.
64 BLOCK_SUPERCONTEXT points to the parent block.
65 For a block which represents the outermost scope of a function, it
66 points to the FUNCTION_DECL node.
67 BLOCK_VARS points to a chain of decl nodes.
68 BLOCK_TYPE_TAGS points to a chain of types which have their own names.
69 BLOCK_CHAIN points to the next BLOCK at the same level.
70 BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which
71 this block is an instance of, or else is NULL to indicate that this
72 block is not an instance of anything else. When non-NULL, the value
73 could either point to another BLOCK node or it could point to a
74 FUNCTION_DECL node (e.g. in the case of a block representing the
75 outermost scope of a particular inlining of a function).
76 BLOCK_ABSTRACT is nonzero if the block represents an abstract
77 instance of a block (i.e. one which is nested within an abstract
78 instance of an inline function).
79 TREE_ASM_WRITTEN is nonzero if the block was actually referenced
80 in the generated assembly. */
81 DEFTREECODE (BLOCK, "block", tcc_exceptional, 0)
82 \f
83 /* Each data type is represented by a tree node whose code is one of
84 the following: */
85 /* Each node that represents a data type has a component TYPE_SIZE
86 containing a tree that is an expression for the size in bits.
87 The TYPE_MODE contains the machine mode for values of this type.
88 The TYPE_POINTER_TO field contains a type for a pointer to this type,
89 or zero if no such has been created yet.
90 The TYPE_NEXT_VARIANT field is used to chain together types
91 that are variants made by type modifiers such as "const" and "volatile".
92 The TYPE_MAIN_VARIANT field, in any member of such a chain,
93 points to the start of the chain.
94 The TYPE_NONCOPIED_PARTS field is a list specifying which parts
95 of an object of this type should *not* be copied by assignment.
96 The TREE_VALUE of each is a FIELD_DECL that should not be
97 copied. The TREE_PURPOSE is an initial value for that field when
98 an object of this type is initialized via an INIT_EXPR. It may
99 be NULL if no special value is required. Even the things in this
100 list are copied if the right-hand side of an assignment is known
101 to be a complete object (rather than being, perhaps, a subobject
102 of some other object.) The determination of what constitutes a
103 complete object is done by fixed_type_p.
104 The TYPE_NAME field contains info on the name used in the program
105 for this type (for GDB symbol table output). It is either a
106 TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
107 in the case of structs, unions or enums that are known with a tag,
108 or zero for types that have no special name.
109 The TYPE_CONTEXT for any sort of type which could have a name or
110 which could have named members (e.g. tagged types in C/C++) will
111 point to the node which represents the scope of the given type, or
112 will be NULL_TREE if the type has "file scope". For most types, this
113 will point to a BLOCK node or a FUNCTION_DECL node, but it could also
114 point to a FUNCTION_TYPE node (for types whose scope is limited to the
115 formal parameter list of some function type specification) or it
116 could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node
117 (for C++ "member" types).
118 For non-tagged-types, TYPE_CONTEXT need not be set to anything in
119 particular, since any type which is of some type category (e.g.
120 an array type or a function type) which cannot either have a name
121 itself or have named members doesn't really have a "scope" per se.
122 The TREE_CHAIN field is used as a forward-references to names for
123 ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
124 see below. */
125
126 /* The ordering of the following codes is optimized for the checking
127 macros in tree.h. Changing the order will degrade the speed of the
128 compiler. OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, CHAR_TYPE,
129 INTEGER_TYPE, REAL_TYPE, POINTER_TYPE. */
130
131 /* An offset is a pointer relative to an object.
132 The TREE_TYPE field is the type of the object at the offset.
133 The TYPE_OFFSET_BASETYPE points to the node for the type of object
134 that the offset is relative to. */
135 DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0)
136
137 /* C enums. The type node looks just like an INTEGER_TYPE node.
138 The symbols for the values of the enum type are defined by
139 CONST_DECL nodes, but the type does not point to them;
140 however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE
141 is a name and the TREE_VALUE is the value (an INTEGER_CST node). */
142 /* A forward reference `enum foo' when no enum named foo is defined yet
143 has zero (a null pointer) in its TYPE_SIZE. The tag name is in
144 the TYPE_NAME field. If the type is later defined, the normal
145 fields are filled in.
146 RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are
147 treated similarly. */
148 DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0)
149
150 /* Boolean type (true or false are the only values). Looks like an
151 INTEGRAL_TYPE. */
152 DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0)
153
154 /* CHAR in Java; not used in C. Looks like an INTEGRAL_TYPE. */
155 DEFTREECODE (CHAR_TYPE, "char_type", tcc_type, 0)
156
157 /* Integer types in all languages, including char in C.
158 Also used for sub-ranges of other discrete types.
159 Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
160 and TYPE_PRECISION (number of bits used by this type).
161 In the case of a subrange type in Pascal, the TREE_TYPE
162 of this will point at the supertype (another INTEGER_TYPE,
163 or an ENUMERAL_TYPE, CHAR_TYPE, or BOOLEAN_TYPE).
164 Otherwise, the TREE_TYPE is zero. */
165 DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0)
166
167 /* C's float and double. Different floating types are distinguished
168 by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */
169 DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0)
170
171 /* The ordering of the following codes is optimized for the checking
172 macros in tree.h. Changing the order will degrade the speed of the
173 compiler. POINTER_TYPE, REFERENCE_TYPE. Note that this range
174 overlaps the previous range of ordered types. */
175
176 /* All pointer-to-x types have code POINTER_TYPE.
177 The TREE_TYPE points to the node for the type pointed to. */
178 DEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0)
179
180 /* A reference is like a pointer except that it is coerced
181 automatically to the value it points to. Used in C++. */
182 DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0)
183
184 /* The ordering of the following codes is optimized for the checking
185 macros in tree.h. Changing the order will degrade the speed of the
186 compiler. COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE. */
187
188 /* Complex number types. The TREE_TYPE field is the data type
189 of the real and imaginary parts. */
190 DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0)
191
192 /* Vector types. The TREE_TYPE field is the data type of the vector
193 elements. The TYPE_PRECISION field is the number of subparts of
194 the vector. */
195 DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0)
196
197 /* The ordering of the following codes is optimized for the checking
198 macros in tree.h. Changing the order will degrade the speed of the
199 compiler. ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE.
200 Note that this range overlaps the previous range. */
201
202 /* Types of arrays. Special fields:
203 TREE_TYPE Type of an array element.
204 TYPE_DOMAIN Type to index by.
205 Its range of values specifies the array length.
206 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
207 and holds the type to coerce a value of that array type to in C.
208 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
209 in languages (such as Chill) that make a distinction. */
210 /* Array types in C or Pascal */
211 DEFTREECODE (ARRAY_TYPE, "array_type", tcc_type, 0)
212
213 /* Struct in C, or record in Pascal. */
214 /* Special fields:
215 TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct,
216 and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables,
217 types and enumerators.
218 A few may need to be added for Pascal. */
219 /* See the comment above, before ENUMERAL_TYPE, for how
220 forward references to struct tags are handled in C. */
221 DEFTREECODE (RECORD_TYPE, "record_type", tcc_type, 0)
222
223 /* Union in C. Like a struct, except that the offsets of the fields
224 will all be zero. */
225 /* See the comment above, before ENUMERAL_TYPE, for how
226 forward references to union tags are handled in C. */
227 DEFTREECODE (UNION_TYPE, "union_type", tcc_type, 0) /* C union type */
228
229 /* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
230 in each FIELD_DECL determine what the union contains. The first
231 field whose DECL_QUALIFIER expression is true is deemed to occupy
232 the union. */
233 DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0)
234
235 /* The ordering of the following codes is optimized for the checking
236 macros in tree.h. Changing the order will degrade the speed of the
237 compiler. VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE. */
238
239 /* The void type in C */
240 DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0)
241
242 /* Type of functions. Special fields:
243 TREE_TYPE type of value returned.
244 TYPE_ARG_TYPES list of types of arguments expected.
245 this list is made of TREE_LIST nodes.
246 Types of "Procedures" in languages where they are different from functions
247 have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */
248 DEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0)
249
250 /* METHOD_TYPE is the type of a function which takes an extra first
251 argument for "self", which is not present in the declared argument list.
252 The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE
253 is the type of "self". TYPE_ARG_TYPES is the real argument list, which
254 includes the hidden argument for "self". */
255 DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0)
256
257 /* This is a language-specific kind of type.
258 Its meaning is defined by the language front end.
259 layout_type does not know how to lay this out,
260 so the front-end must do so manually. */
261 DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0)
262 \f
263 /* Expressions */
264
265 /* First, the constants. */
266
267 /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
268 32 bits each, giving us a 64 bit constant capability. INTEGER_CST
269 nodes can be shared, and therefore should be considered read only.
270 They should be copied, before setting a flag such as
271 TREE_OVERFLOW. If an INTEGER_CST has TREE_OVERFLOW or
272 TREE_CONSTANT_OVERFLOW already set, it is known to be unique.
273 INTEGER_CST nodes are created for the integral types, for pointer
274 types and for vector and float types in some circumstances. */
275 DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0)
276
277 /* Contents are in TREE_REAL_CST field. */
278 DEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0)
279
280 /* Contents are in TREE_REALPART and TREE_IMAGPART fields,
281 whose contents are other constant nodes. */
282 DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0)
283
284 /* Contents are in TREE_VECTOR_CST_ELTS field. */
285 DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0)
286
287 /* Contents are TREE_STRING_LENGTH and the actual contents of the string. */
288 DEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0)
289
290 /* Declarations. All references to names are represented as ..._DECL
291 nodes. The decls in one binding context are chained through the
292 TREE_CHAIN field. Each DECL has a DECL_NAME field which contains
293 an IDENTIFIER_NODE. (Some decls, most often labels, may have zero
294 as the DECL_NAME). DECL_CONTEXT points to the node representing
295 the context in which this declaration has its scope. For
296 FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or
297 QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL,
298 PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this
299 points to either the FUNCTION_DECL for the containing function, the
300 RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or
301 a TRANSLATION_UNIT_DECL if the given decl has "file scope".
302 DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
303 ..._DECL node of which this decl is an (inlined or template expanded)
304 instance.
305 The TREE_TYPE field holds the data type of the object, when relevant.
306 LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field
307 contents are the type whose name is being declared.
308 The DECL_ALIGN, DECL_SIZE,
309 and DECL_MODE fields exist in decl nodes just as in type nodes.
310 They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
311
312 DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for
313 the location. DECL_VOFFSET holds an expression for a variable
314 offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer).
315 These fields are relevant only in FIELD_DECLs and PARM_DECLs.
316
317 DECL_INITIAL holds the value to initialize a variable to,
318 or the value of a constant. For a function, it holds the body
319 (a node of type BLOCK representing the function's binding contour
320 and whose body contains the function's statements.) For a LABEL_DECL
321 in C, it is a flag, nonzero if the label's definition has been seen.
322
323 PARM_DECLs use a special field:
324 DECL_ARG_TYPE is the type in which the argument is actually
325 passed, which may be different from its type within the function.
326
327 FUNCTION_DECLs use four special fields:
328 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
329 DECL_RESULT holds a RESULT_DECL node for the value of a function.
330 The DECL_RTL field is 0 for a function that returns no value.
331 (C functions returning void have zero here.)
332 The TREE_TYPE field is the type in which the result is actually
333 returned. This is usually the same as the return type of the
334 FUNCTION_DECL, but it may be a wider integer type because of
335 promotion.
336 DECL_FUNCTION_CODE is a code number that is nonzero for
337 built-in functions. Its value is an enum built_in_function
338 that says which built-in function it is.
339
340 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
341 holds a line number. In some cases these can be the location of
342 a reference, if no definition has been seen.
343
344 DECL_ABSTRACT is nonzero if the decl represents an abstract instance
345 of a decl (i.e. one which is nested within an abstract instance of a
346 inline function. */
347
348 DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0)
349 DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0)
350 /* The ordering of the following codes is optimized for the checking
351 macros in tree.h. Changing the order will degrade the speed of the
352 compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL,
353 TYPE_DECL. */
354 DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0)
355 DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0)
356 DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0)
357 DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0)
358 DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0)
359 DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0)
360
361 /* Memory tags used in tree-ssa to represent memory locations in
362 virtual SSA. */
363 DEFTREECODE (STRUCT_FIELD_TAG, "struct_field_tag", tcc_declaration, 0)
364 DEFTREECODE (NAME_MEMORY_TAG, "name_memory_tag", tcc_declaration, 0)
365 DEFTREECODE (TYPE_MEMORY_TAG, "type_memory_tag", tcc_declaration, 0)
366
367 /* A namespace declaration. Namespaces appear in DECL_CONTEXT of other
368 _DECLs, providing a hierarchy of names. */
369 DEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0)
370
371 /* A translation unit. This is not technically a declaration, since it
372 can't be looked up, but it's close enough. */
373 DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\
374 tcc_declaration, 0)
375 \f
376 /* References to storage. */
377
378 /* Value is structure or union component.
379 Operand 0 is the structure or union (an expression).
380 Operand 1 is the field (a node of type FIELD_DECL).
381 Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured
382 in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT. */
383 DEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3)
384
385 /* Reference to a group of bits within an object. Similar to COMPONENT_REF
386 except the position is given explicitly rather than via a FIELD_DECL.
387 Operand 0 is the structure or union expression;
388 operand 1 is a tree giving the number of bits being referenced;
389 operand 2 is a tree giving the position of the first referenced bit.
390 The field can be either a signed or unsigned field;
391 BIT_FIELD_REF_UNSIGNED says which. */
392 DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3)
393
394 /* The ordering of the following codes is optimized for the checking
395 macros in tree.h. Changing the order will degrade the speed of the
396 compiler. INDIRECT_REF, ALIGN_INDIRECT_REF, MISALIGNED_INDIRECT_REF. */
397
398 /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */
399 DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1)
400
401 /* Like above, but aligns the referenced address (i.e, if the address
402 in P is not aligned on TYPE_ALIGN boundary, then &(*P) != P). */
403 DEFTREECODE (ALIGN_INDIRECT_REF, "align_indirect_ref", tcc_reference, 1)
404
405 /* Same as INDIRECT_REF, but also specifies the alignment of the referenced
406 address:
407 Operand 0 is the referenced address (a pointer);
408 Operand 1 is an INTEGER_CST which represents the alignment of the address,
409 or 0 if the alignment is unknown. */
410 DEFTREECODE (MISALIGNED_INDIRECT_REF, "misaligned_indirect_ref", tcc_reference, 2)
411
412 /* Array indexing.
413 Operand 0 is the array; operand 1 is a (single) array index.
414 Operand 2, if present, is a copy of TYPE_MIN_VALUE of the index.
415 Operand 3, if present, is the element size, measured in units of
416 the alignment of the element type. */
417 DEFTREECODE (ARRAY_REF, "array_ref", tcc_reference, 4)
418
419 /* Likewise, except that the result is a range ("slice") of the array. The
420 starting index of the resulting array is taken from operand 1 and the size
421 of the range is taken from the type of the expression. */
422 DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4)
423
424 /* Used to represent lookup of runtime type dependent data. Often this is
425 a reference to a vtable, but it needn't be. Operands are:
426 OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use.
427 OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is
428 being performed. Through this the optimizers may be able to statically
429 determine the dynamic type of the object.
430 OBJ_TYPE_REF_TOKEN: Something front-end specific used to resolve the
431 reference to something simpler, usually to the address of a DECL.
432 Never touched by the middle-end. Good choices would be either an
433 identifier or a vtable index. */
434 DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3)
435
436 /* The exception object from the runtime. */
437 DEFTREECODE (EXC_PTR_EXPR, "exc_ptr_expr", tcc_expression, 0)
438
439 /* The filter object from the runtime. */
440 DEFTREECODE (FILTER_EXPR, "filter_expr", tcc_expression, 0)
441
442 /* Constructor: return an aggregate value made from specified components.
443 In C, this is used only for structure and array initializers.
444 The operand is a sequence of component values made out of a VEC of
445 struct constructor_elt.
446
447 For ARRAY_TYPE:
448 The field INDEX of each constructor_elt is the corresponding index.
449 If the index is a RANGE_EXPR, it is a short-hand for many nodes,
450 one for each index in the range. (If the corresponding field VALUE
451 has side-effects, they are evaluated once for each element. Wrap the
452 value in a SAVE_EXPR if you want to evaluate side effects only once.)
453
454 For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE:
455 The field INDEX of each node is a FIELD_DECL. */
456 DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0)
457
458 /* The expression types are mostly straightforward, with the fourth argument
459 of DEFTREECODE saying how many operands there are.
460 Unless otherwise specified, the operands are expressions and the
461 types of all the operands and the expression must all be the same. */
462
463 /* Contains two expressions to compute, one followed by the other.
464 the first value is ignored. The second one's value is used. The
465 type of the first expression need not agree with the other types. */
466 DEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2)
467
468 /* Assignment expression. Operand 0 is the what to set; 1, the new value. */
469 DEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2)
470
471 /* Initialization expression. Operand 0 is the variable to initialize;
472 Operand 1 is the initializer. */
473 DEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2)
474
475 /* For TARGET_EXPR, operand 0 is the target of an initialization,
476 operand 1 is the initializer for the target, which may be void
477 if simply expanding it initializes the target.
478 operand 2 is the cleanup for this node, if any.
479 operand 3 is the saved initializer after this node has been
480 expanded once; this is so we can re-expand the tree later. */
481 DEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4)
482
483 /* Conditional expression ( ... ? ... : ... in C).
484 Operand 0 is the condition.
485 Operand 1 is the then-value.
486 Operand 2 is the else-value.
487 Operand 0 may be of any type.
488 Operand 1 must have the same type as the entire expression, unless
489 it unconditionally throws an exception, in which case it should
490 have VOID_TYPE. The same constraints apply to operand 2. */
491 DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3)
492
493 /* Vector conditional expression. It is like COND_EXPR, but with
494 vector operands.
495
496 A = VEC_COND_EXPR ( X < Y, B, C)
497
498 means
499
500 for (i=0; i<N; i++)
501 A[i] = X[i] < Y[i] ? B[i] : C[i];
502 */
503 DEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3)
504
505 /* Declare local variables, including making RTL and allocating space.
506 BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables.
507 BIND_EXPR_BODY is the body, the expression to be computed using
508 the variables. The value of operand 1 becomes that of the BIND_EXPR.
509 BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings
510 for debugging purposes. If this BIND_EXPR is actually expanded,
511 that sets the TREE_USED flag in the BLOCK.
512
513 The BIND_EXPR is not responsible for informing parsers
514 about these variables. If the body is coming from the input file,
515 then the code that creates the BIND_EXPR is also responsible for
516 informing the parser of the variables.
517
518 If the BIND_EXPR is ever expanded, its TREE_USED flag is set.
519 This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
520 If the BIND_EXPR should be output for debugging but will not be expanded,
521 set the TREE_USED flag by hand.
522
523 In order for the BIND_EXPR to be known at all, the code that creates it
524 must also install it as a subblock in the tree of BLOCK
525 nodes for the function. */
526 DEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3)
527
528 /* Function call. Operand 0 is the function.
529 Operand 1 is the argument list, a list of expressions
530 made out of a chain of TREE_LIST nodes.
531 Operand 2 is the static chain argument, or NULL. */
532 DEFTREECODE (CALL_EXPR, "call_expr", tcc_expression, 3)
533
534 /* Specify a value to compute along with its corresponding cleanup.
535 Operand 0 is the cleanup expression.
536 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR,
537 which must exist. This differs from TRY_CATCH_EXPR in that operand 1
538 is always evaluated when cleanups are run. */
539 DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1)
540
541 /* Specify a cleanup point.
542 Operand 0 is an expression that may have cleanups. If it does, those
543 cleanups are executed after the expression is expanded.
544
545 Note that if the expression is a reference to storage, it is forced out
546 of memory before the cleanups are run. This is necessary to handle
547 cases where the cleanups modify the storage referenced; in the
548 expression 't.i', if 't' is a struct with an integer member 'i' and a
549 cleanup which modifies 'i', the value of the expression depends on
550 whether the cleanup is run before or after 't.i' is evaluated. When
551 expand_expr is run on 't.i', it returns a MEM. This is not good enough;
552 the value of 't.i' must be forced out of memory.
553
554 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
555 BLKmode, because it will not be forced out of memory. */
556 DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1)
557
558 /* The following two codes are used in languages that have types where
559 some field in an object of the type contains a value that is used in
560 the computation of another field's offset or size and/or the size of
561 the type. The positions and/or sizes of fields can vary from object
562 to object of the same type or even for one and the same object within
563 its scope.
564
565 Record types with discriminants in Ada or schema types in Pascal are
566 examples of such types. This mechanism is also used to create "fat
567 pointers" for unconstrained array types in Ada; the fat pointer is a
568 structure one of whose fields is a pointer to the actual array type
569 and the other field is a pointer to a template, which is a structure
570 containing the bounds of the array. The bounds in the type pointed
571 to by the first field in the fat pointer refer to the values in the
572 template.
573
574 When you wish to construct such a type you need "self-references"
575 that allow you to reference the object having this type from the
576 TYPE node, i.e. without having a variable instantiating this type.
577
578 Such a "self-references" is done using a PLACEHOLDER_EXPR. This is
579 a node that will later be replaced with the object being referenced.
580 Its type is that of the object and selects which object to use from
581 a chain of references (see below). No other slots are used in the
582 PLACEHOLDER_EXPR.
583
584 For example, if your type FOO is a RECORD_TYPE with a field BAR,
585 and you need the value of <variable>.BAR to calculate TYPE_SIZE
586 (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR
587 whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with
588 the PLACEHOLDER_EXPR as the first operand (which has the correct
589 type). Later, when the size is needed in the program, the back-end
590 will find this PLACEHOLDER_EXPR and generate code to calculate the
591 actual size at run-time. In the following, we describe how this
592 calculation is done.
593
594 When we wish to evaluate a size or offset, we check whether it contains a
595 PLACEHOLDER_EXPR. If it does, we call substitute_placeholder_in_expr
596 passing both that tree and an expression within which the object may be
597 found. The latter expression is the object itself in the simple case of
598 an Ada record with discriminant, but it can be the array in the case of an
599 unconstrained array.
600
601 In the latter case, we need the fat pointer, because the bounds of
602 the array can only be accessed from it. However, we rely here on the
603 fact that the expression for the array contains the dereference of
604 the fat pointer that obtained the array pointer. */
605
606 /* Denotes a record to later be substituted before evaluating this expression.
607 The type of this expression is used to find the record to replace it. */
608 DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0)
609
610 /* Simple arithmetic. */
611 DEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2)
612 DEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2)
613 DEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2)
614
615 /* Division for integer result that rounds the quotient toward zero. */
616 DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2)
617
618 /* Division for integer result that rounds the quotient toward infinity. */
619 DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2)
620
621 /* Division for integer result that rounds toward minus infinity. */
622 DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2)
623
624 /* Division for integer result that rounds toward nearest integer. */
625 DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2)
626
627 /* Four kinds of remainder that go with the four kinds of division. */
628 DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2)
629 DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2)
630 DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2)
631 DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2)
632
633 /* Division for real result. */
634 DEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2)
635
636 /* Division which is not supposed to need rounding.
637 Used for pointer subtraction in C. */
638 DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2)
639
640 /* Conversion of real to fixed point: four ways to round,
641 like the four ways to divide.
642 CONVERT_EXPR can also be used to convert a real to an integer,
643 and that is what is used in languages that do not have ways of
644 specifying which of these is wanted. Maybe these are not needed. */
645 DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1)
646 DEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", tcc_unary, 1)
647 DEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", tcc_unary, 1)
648 DEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", tcc_unary, 1)
649
650 /* Conversion of an integer to a real. */
651 DEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1)
652
653 /* Unary negation. */
654 DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1)
655
656 /* Minimum and maximum values. When used with floating point, if both
657 operands are zeros, or if either operand is NaN, then it is unspecified
658 which of the two operands is returned as the result. */
659 DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2)
660 DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2)
661
662 /* Represents the absolute value of the operand.
663
664 An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The
665 operand of the ABS_EXPR must have the same type. */
666 DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1)
667
668 /* Shift operations for shift and rotate.
669 Shift means logical shift if done on an
670 unsigned type, arithmetic shift if done on a signed type.
671 The second operand is the number of bits to
672 shift by; it need not be the same type as the first operand and result.
673 Note that the result is undefined if the second operand is larger
674 than or equal to the first operand's type size. */
675 DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2)
676 DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2)
677 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2)
678 DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2)
679
680 /* Bitwise operations. Operands have same mode as result. */
681 DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2)
682 DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2)
683 DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2)
684 DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1)
685
686 /* ANDIF and ORIF allow the second operand not to be computed if the
687 value of the expression is determined from the first operand. AND,
688 OR, and XOR always compute the second operand whether its value is
689 needed or not (for side effects). The operand may have
690 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be
691 either zero or one. For example, a TRUTH_NOT_EXPR will never have
692 an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
693 used to compare the VAR_DECL to zero, thereby obtaining a node with
694 value zero or one. */
695 DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2)
696 DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2)
697 DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2)
698 DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2)
699 DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2)
700 DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1)
701
702 /* Relational operators.
703 `EQ_EXPR' and `NE_EXPR' are allowed for any types.
704 The others are allowed only for integer (or pointer or enumeral)
705 or real types.
706 In all cases the operands will have the same type,
707 and the value is always the type used by the language for booleans. */
708 DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2)
709 DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2)
710 DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2)
711 DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2)
712 DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2)
713 DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2)
714
715 /* Additional relational operators for floating point unordered. */
716 DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2)
717 DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2)
718
719 /* These are equivalent to unordered or ... */
720 DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2)
721 DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2)
722 DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2)
723 DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2)
724 DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2)
725
726 /* This is the reverse of uneq_expr. */
727 DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2)
728
729 DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2)
730
731 /* Represents a conversion of type of a value.
732 All conversions, including implicit ones, must be
733 represented by CONVERT_EXPR or NOP_EXPR nodes. */
734 DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1)
735
736 /* Represents a conversion expected to require no code to be generated. */
737 DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1)
738
739 /* Value is same as argument, but guaranteed not an lvalue. */
740 DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1)
741
742 /* Represents viewing something of one type as being of a second type.
743 This corresponds to an "Unchecked Conversion" in Ada and roughly to
744 the idiom *(type2 *)&X in C. The only operand is the value to be
745 viewed as being of another type. It is undefined if the type of the
746 input and of the expression have different sizes.
747
748 This code may also be used within the LHS of a MODIFY_EXPR, in which
749 case no actual data motion may occur. TREE_ADDRESSABLE will be set in
750 this case and GCC must abort if it could not do the operation without
751 generating insns. */
752 DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1)
753
754 /* Represents something we computed once and will use multiple times.
755 First operand is that expression. After it is evaluated once, it
756 will be replaced by the temporary variable that holds the value. */
757 DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1)
758
759 /* & in C. Value is the address at which the operand's value resides.
760 Operand may have any mode. Result mode is Pmode. */
761 DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1)
762
763 /* Operand0 is a function constant; result is part N of a function
764 descriptor of type ptr_mode. */
765 DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2)
766
767 /* Given two real or integer operands of the same type,
768 returns a complex value of the corresponding complex type. */
769 DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2)
770
771 /* Complex conjugate of operand. Used only on complex types. */
772 DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1)
773
774 /* Used only on an operand of complex type, these return
775 a value of the corresponding component type. */
776 DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1)
777 DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1)
778
779 /* Nodes for ++ and -- in C.
780 The second arg is how much to increment or decrement by.
781 For a pointer, it would be the size of the object pointed to. */
782 DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2)
783 DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2)
784 DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2)
785 DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2)
786
787 /* Used to implement `va_arg'. */
788 DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1)
789
790 /* Evaluate operand 1. If and only if an exception is thrown during
791 the evaluation of operand 1, evaluate operand 2.
792
793 This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated
794 on a normal or jump exit, only on an exception. */
795 DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2)
796
797 /* Evaluate the first operand.
798 The second operand is a cleanup expression which is evaluated
799 on any exit (normal, exception, or jump out) from this expression. */
800 DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2)
801 \f
802 /* These types of expressions have no useful value,
803 and always have side effects. */
804
805 /* Used to represent a local declaration. The operand is DECL_EXPR_DECL. */
806 DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1)
807
808 /* A label definition, encapsulated as a statement.
809 Operand 0 is the LABEL_DECL node for the label that appears here.
810 The type should be void and the value should be ignored. */
811 DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1)
812
813 /* GOTO. Operand 0 is a LABEL_DECL node or an expression.
814 The type should be void and the value should be ignored. */
815 DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1)
816
817 /* RETURN. Evaluates operand 0, then returns from the current function.
818 Presumably that operand is an assignment that stores into the
819 RESULT_DECL that hold the value to be returned.
820 The operand may be null.
821 The type should be void and the value should be ignored. */
822 DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1)
823
824 /* Exit the inner most loop conditionally. Operand 0 is the condition.
825 The type should be void and the value should be ignored. */
826 DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1)
827
828 /* A loop. Operand 0 is the body of the loop.
829 It must contain an EXIT_EXPR or is an infinite loop.
830 The type should be void and the value should be ignored. */
831 DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1)
832
833 /* Switch expression.
834
835 TREE_TYPE is the original type of the condition, before any
836 language required type conversions. It may be NULL, in which case
837 the original type and final types are assumed to be the same.
838
839 Operand 0 is the expression used to perform the branch,
840 Operand 1 is the body of the switch, which probably contains
841 CASE_LABEL_EXPRs. It may also be NULL, in which case operand 2
842 must not be NULL.
843 Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs
844 of all the cases. */
845 DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3)
846
847 /* Used to represent a case label. The operands are CASE_LOW and
848 CASE_HIGH, respectively. If CASE_LOW is NULL_TREE, the label is a
849 'default' label. If CASE_HIGH is NULL_TREE, the label is a normal case
850 label. CASE_LABEL is the corresponding LABEL_DECL. */
851 DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 3)
852
853 /* RESX. Resume execution after an exception. Operand 0 is a
854 number indicating the exception region that is being left. */
855 DEFTREECODE (RESX_EXPR, "resx_expr", tcc_statement, 1)
856
857 /* Used to represent an inline assembly statement. ASM_STRING returns a
858 STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS,
859 ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers
860 for the statement. */
861 DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 4)
862
863 /* Variable references for SSA analysis. New SSA names are created every
864 time a variable is assigned a new value. The SSA builder uses SSA_NAME
865 nodes to implement SSA versioning. */
866 DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0)
867
868 /* SSA PHI operator. PHI_RESULT is the new SSA_NAME node created by
869 the PHI node. PHI_ARG_LENGTH is the number of arguments.
870 PHI_ARG_ELT returns the Ith tuple <ssa_name, edge> from the
871 argument list. Each tuple contains the incoming reaching
872 definition (SSA_NAME node) and the edge via which that definition
873 is coming through. */
874 DEFTREECODE (PHI_NODE, "phi_node", tcc_exceptional, 0)
875
876 /* Used to represent a typed exception handler. CATCH_TYPES is the type (or
877 list of types) handled, and CATCH_BODY is the code for the handler. */
878 DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2)
879
880 /* Used to represent an exception specification. EH_FILTER_TYPES is a list
881 of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on
882 failure. EH_FILTER_MUST_NOT_THROW controls which range type to use when
883 expanding. */
884 DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2)
885
886 /* Node used for describing a property that is known at compile
887 time. */
888 DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0)
889
890 /* Node used for describing a property that is not known at compile
891 time. */
892 DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0)
893
894 /* Polynomial chains of recurrences.
895 Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}. */
896 DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3)
897
898 /* Used to chain children of container statements together.
899 Use the interface in tree-iterator.h to access this node. */
900 DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0)
901
902 /* Value handles. Artificial nodes to represent expressions in
903 partial redundancy elimination (tree-ssa-pre.c). These nodes are
904 used for expression canonicalization. If two expressions compute
905 the same value, they will be assigned the same value handle. */
906 DEFTREECODE (VALUE_HANDLE, "value_handle", tcc_exceptional, 0)
907
908 /* Predicate assertion. Artificial expression generated by the optimizers
909 to keep track of predicate values. This expression may only appear on
910 the RHS of assignments.
911
912 Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer
913 two things:
914
915 1- X is a copy of Y.
916 2- EXPR is a GIMPLE conditional expression (as defined by
917 is_gimple_condexpr) and is known to be true.
918
919 The type of the expression is the same as Y. */
920 DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2)
921
922 /* Base class information. Holds information about a class as a
923 baseclass of itself or another class. */
924 DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0)
925
926 /* Records the size for an expression of variable size type. This is
927 for use in contexts in which we are accessing the entire object,
928 such as for a function call, or block copy.
929 Operand 0 is the real expression.
930 Operand 1 is the size of the type in the expression. */
931 DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2)
932
933 /* Extract elements from two input vectors Operand 0 and Operand 1
934 size VS, according to the offset OFF defined by Operand 2 as
935 follows:
936 If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to
937 the first OFF elements of the vector OP1.
938 If OFF == 0, then the returned vector is OP1.
939 On different targets OFF may take different forms; It can be an address, in
940 which case its low log2(VS)-1 bits define the offset, or it can be a mask
941 generated by the builtin targetm.vectorize.mask_for_load_builtin_decl. */
942 DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3)
943
944 /* Low-level memory addressing. Operands are SYMBOL (static or global
945 variable), BASE (register), INDEX (register), STEP (integer constant),
946 OFFSET (integer constant). Corresponding address is
947 SYMBOL + BASE + STEP * INDEX + OFFSET. Only variations and values valid on
948 the target are allowed.
949
950 The sixth argument is the reference to the original memory access, which
951 is preserved for the purposes of the RTL alias analysis. The seventh
952 argument is a tag representing results of the tree level alias analysis. */
953
954 DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 7)
955
956 /* The ordering of the codes between OMP_PARALLEL and OMP_CRITICAL is
957 exposed to TREE_RANGE_CHECK. */
958 /* OpenMP - #pragma omp parallel [clause1 ... clauseN]
959 Operand 0: OMP_PARALLEL_BODY: Code to be executed by all threads.
960 Operand 1: OMP_PARALLEL_CLAUSES: List of clauses. */
961 DEFTREECODE (OMP_PARALLEL, "omp_parallel", tcc_statement, 2)
962
963 /* OpenMP - #pragma omp for [clause1 ... clauseN]
964 Operand 0: OMP_FOR_BODY: Loop body.
965 Operand 1: OMP_FOR_CLAUSES: List of clauses.
966 Operand 2: OMP_FOR_INIT: Initialization code of the form
967 VAR = N1.
968 Operand 3: OMP_FOR_COND: Loop conditional expression of the form
969 VAR { <, >, <=, >= } N2.
970 Operand 4: OMP_FOR_INCR: Loop index increment of the form
971 VAR { +=, -= } INCR.
972 Operand 5: OMP_FOR_PRE_BODY: Filled by the gimplifier with things
973 from INIT, COND, and INCR that are technically part of the
974 OMP_FOR structured block, but are evaluated before the loop
975 body begins.
976
977 VAR must be a signed integer variable, which is implicitly thread
978 private. N1, N2 and INCR are required to be loop invariant integer
979 expressions that are evaluated without any synchronization.
980 The evaluation order, frequency of evaluation and side-effects are
981 unspecified by the standard. */
982 DEFTREECODE (OMP_FOR, "omp_for", tcc_statement, 6)
983
984 /* OpenMP - #pragma omp sections [clause1 ... clauseN]
985 Operand 0: OMP_SECTIONS_BODY: Sections body.
986 Operand 1: OMP_SECTIONS_CLAUSES: List of clauses. */
987 DEFTREECODE (OMP_SECTIONS, "omp_sections", tcc_statement, 2)
988
989 /* OpenMP - #pragma omp single
990 Operand 0: OMP_SINGLE_BODY: Single section body.
991 Operand 1: OMP_SINGLE_CLAUSES: List of clauses. */
992 DEFTREECODE (OMP_SINGLE, "omp_single", tcc_statement, 2)
993
994 /* OpenMP - #pragma omp section
995 Operand 0: OMP_SECTION_BODY: Section body. */
996 DEFTREECODE (OMP_SECTION, "omp_section", tcc_statement, 1)
997
998 /* OpenMP - #pragma omp master
999 Operand 0: OMP_MASTER_BODY: Master section body. */
1000 DEFTREECODE (OMP_MASTER, "omp_master", tcc_statement, 1)
1001
1002 /* OpenMP - #pragma omp ordered
1003 Operand 0: OMP_ORDERED_BODY: Master section body. */
1004 DEFTREECODE (OMP_ORDERED, "omp_ordered", tcc_statement, 1)
1005
1006 /* OpenMP - #pragma omp critical [name]
1007 Operand 0: OMP_CRITICAL_BODY: Critical section body.
1008 Operand 1: OMP_CRITICAL_NAME: Identifier for critical section. */
1009 DEFTREECODE (OMP_CRITICAL, "omp_critical", tcc_statement, 2)
1010
1011 /* OpenMP - #pragma omp atomic
1012 Operand 0: The address at which the atomic operation is to be performed.
1013 This address should be stabilized with save_expr.
1014 Operand 1: The expression to evaluate. When the old value of the object
1015 at the address is used in the expression, it should appear as if
1016 build_fold_indirect_ref of the address. */
1017 DEFTREECODE (OMP_ATOMIC, "omp_atomic", tcc_statement, 2)
1018
1019 /* The ordering of the codes between OMP_CLAUSE_PRIVATE and
1020 OMP_CLAUSE_DEFAULT is exposed to TREE_RANGE_CHECK. */
1021 /* OpenMP clause: private (variable_list). */
1022 DEFTREECODE (OMP_CLAUSE_PRIVATE, "private", tcc_expression, 1)
1023
1024 /* OpenMP clause: shared (variable_list). */
1025 DEFTREECODE (OMP_CLAUSE_SHARED, "shared", tcc_expression, 1)
1026
1027 /* OpenMP clause: firstprivate (variable_list). */
1028 DEFTREECODE (OMP_CLAUSE_FIRSTPRIVATE, "firstprivate", tcc_expression, 1)
1029
1030 /* OpenMP clause: lastprivate (variable_list). */
1031 DEFTREECODE (OMP_CLAUSE_LASTPRIVATE, "lastprivate", tcc_expression, 1)
1032
1033 /* OpenMP clause: reduction (operator:variable_list).
1034 OMP_CLAUSE_REDUCTION_CODE: The tree_code of the operator.
1035 Operand 1: OMP_CLAUSE_REDUCTION_INIT: Stmt-list to initialize the var.
1036 Operand 2: OMP_CLAUSE_REDUCTION_MERGE:
1037 Stmt-list to merge private var into the shared one.
1038 Operand 3: OMP_CLAUSE_REDUCTION_PLACEHOLDER:
1039 A dummy VAR_DECL placeholder used in OMP_CLAUSE_REDUCTION_MERGE. */
1040 DEFTREECODE (OMP_CLAUSE_REDUCTION, "reduction", tcc_expression, 4)
1041
1042 /* OpenMP clause: copyin (variable_list). */
1043 DEFTREECODE (OMP_CLAUSE_COPYIN, "copyin", tcc_expression, 1)
1044
1045 /* OpenMP clause: copyprivate (variable_list). */
1046 DEFTREECODE (OMP_CLAUSE_COPYPRIVATE, "copyprivate", tcc_expression, 1)
1047
1048 /* OpenMP clause: if (scalar-expression). */
1049 DEFTREECODE (OMP_CLAUSE_IF, "if", tcc_expression, 1)
1050
1051 /* OpenMP clause: num_threads (integer-expression). */
1052 DEFTREECODE (OMP_CLAUSE_NUM_THREADS, "num_threads", tcc_expression, 1)
1053
1054 /* OpenMP clause: schedule. */
1055 DEFTREECODE (OMP_CLAUSE_SCHEDULE, "schedule", tcc_expression, 1)
1056
1057 /* OpenMP clause: nowait. */
1058 DEFTREECODE (OMP_CLAUSE_NOWAIT, "nowait", tcc_expression, 0)
1059
1060 /* OpenMP clause: ordered. */
1061 DEFTREECODE (OMP_CLAUSE_ORDERED, "ordered", tcc_expression, 0)
1062
1063 /* OpenMP clause: default. */
1064 DEFTREECODE (OMP_CLAUSE_DEFAULT, "default", tcc_expression, 0)
1065
1066 /* Reduction operations.
1067 Operations that take a vector of elements and "reduce" it to a scalar
1068 result (e.g. summing the elements of the vector, finding the minimum over
1069 the vector elements, etc).
1070 Operand 0 is a vector; the first element in the vector has the result.
1071 Operand 1 is a vector. */
1072 DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1)
1073 DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1)
1074 DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1)
1075
1076 /* Whole vector left/right shift in bits.
1077 Operand 0 is a vector to be shifted.
1078 Operand 1 is an integer shift amount in bits. */
1079 DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2)
1080 DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2)
1081
1082 /*
1083 Local variables:
1084 mode:c
1085 End:
1086 */