source: arduino-1-6-7/trunk/fuentes/arduino-ide-amd64/hardware/tools/avr/lib/gcc/avr/4.9.2/plugin/include/tree.def @ 4837

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1/* This file contains the definitions and documentation for the
2   tree codes used in GCC.
3   Copyright (C) 1987-2014 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3.  If not see
19<http://www.gnu.org/licenses/>.  */
20
21
22/* For tcc_references, tcc_expression, tcc_comparison, tcc_unary,
23   tcc_binary, and tcc_statement nodes, which use struct tree_exp, the
24   4th element is the number of argument slots to allocate.  This
25   determines the size of the tree node object.  Other nodes use
26   different structures, and the size is determined by the tree_union
27   member structure; the 4th element should be zero.  Languages that
28   define language-specific tcc_exceptional or tcc_constant codes must
29   define the tree_size langhook to say how big they are.
30
31   These tree codes have been sorted so that the macros in tree.h that
32   check for various tree codes are optimized into range checks.  This
33   gives a measurable performance improvement.  When adding a new
34   code, consider its placement in relation to the other codes.  */
35
36/* Any erroneous construct is parsed into a node of this type.
37   This type of node is accepted without complaint in all contexts
38   by later parsing activities, to avoid multiple error messages
39   for one error.
40   No fields in these nodes are used except the TREE_CODE.  */
41DEFTREECODE (ERROR_MARK, "error_mark", tcc_exceptional, 0)
42
43/* Used to represent a name (such as, in the DECL_NAME of a decl node).
44   Internally it looks like a STRING_CST node.
45   There is only one IDENTIFIER_NODE ever made for any particular name.
46   Use `get_identifier' to get it (or create it, the first time).  */
47DEFTREECODE (IDENTIFIER_NODE, "identifier_node", tcc_exceptional, 0)
48
49/* Has the TREE_VALUE and TREE_PURPOSE fields.  */
50/* These nodes are made into lists by chaining through the
51   TREE_CHAIN field.  The elements of the list live in the
52   TREE_VALUE fields, while TREE_PURPOSE fields are occasionally
53   used as well to get the effect of Lisp association lists.  */
54DEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0)
55
56/* These nodes contain an array of tree nodes.  */
57DEFTREECODE (TREE_VEC, "tree_vec", tcc_exceptional, 0)
58
59/* A symbol binding block.  These are arranged in a tree,
60   where the BLOCK_SUBBLOCKS field contains a chain of subblocks
61   chained through the BLOCK_CHAIN field.
62   BLOCK_SUPERCONTEXT points to the parent block.
63     For a block which represents the outermost scope of a function, it
64     points to the FUNCTION_DECL node.
65   BLOCK_VARS points to a chain of decl nodes.
66   BLOCK_CHAIN points to the next BLOCK at the same level.
67   BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which
68   this block is an instance of, or else is NULL to indicate that this
69   block is not an instance of anything else.  When non-NULL, the value
70   could either point to another BLOCK node or it could point to a
71   FUNCTION_DECL node (e.g. in the case of a block representing the
72   outermost scope of a particular inlining of a function).
73   BLOCK_ABSTRACT is nonzero if the block represents an abstract
74   instance of a block (i.e. one which is nested within an abstract
75   instance of an inline function).
76   TREE_ASM_WRITTEN is nonzero if the block was actually referenced
77   in the generated assembly.  */
78DEFTREECODE (BLOCK, "block", tcc_exceptional, 0)
79
80/* Each data type is represented by a tree node whose code is one of
81   the following:  */
82/* Each node that represents a data type has a component TYPE_SIZE
83   containing a tree that is an expression for the size in bits.
84   The TYPE_MODE contains the machine mode for values of this type.
85   The TYPE_POINTER_TO field contains a type for a pointer to this type,
86     or zero if no such has been created yet.
87   The TYPE_NEXT_VARIANT field is used to chain together types
88     that are variants made by type modifiers such as "const" and "volatile".
89   The TYPE_MAIN_VARIANT field, in any member of such a chain,
90     points to the start of the chain.
91   The TYPE_NAME field contains info on the name used in the program
92     for this type (for GDB symbol table output).  It is either a
93     TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE
94     in the case of structs, unions or enums that are known with a tag,
95     or zero for types that have no special name.
96   The TYPE_CONTEXT for any sort of type which could have a name or
97    which could have named members (e.g. tagged types in C/C++) will
98    point to the node which represents the scope of the given type, or
99    will be NULL_TREE if the type has "file scope".  For most types, this
100    will point to a BLOCK node or a FUNCTION_DECL node, but it could also
101    point to a FUNCTION_TYPE node (for types whose scope is limited to the
102    formal parameter list of some function type specification) or it
103    could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node
104    (for C++ "member" types).
105    For non-tagged-types, TYPE_CONTEXT need not be set to anything in
106    particular, since any type which is of some type category  (e.g.
107    an array type or a function type) which cannot either have a name
108    itself or have named members doesn't really have a "scope" per se.
109  The TREE_CHAIN field is used as a forward-references to names for
110    ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes;
111    see below.  */
112
113/* The ordering of the following codes is optimized for the checking
114   macros in tree.h.  Changing the order will degrade the speed of the
115   compiler.  OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, INTEGER_TYPE,
116   REAL_TYPE, POINTER_TYPE.  */
117
118/* An offset is a pointer relative to an object.
119   The TREE_TYPE field is the type of the object at the offset.
120   The TYPE_OFFSET_BASETYPE points to the node for the type of object
121   that the offset is relative to.  */
122DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0)
123
124/* C enums.  The type node looks just like an INTEGER_TYPE node.
125   The symbols for the values of the enum type are defined by
126   CONST_DECL nodes, but the type does not point to them;
127   however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE
128   is a name and the TREE_VALUE is the value (an INTEGER_CST node).  */
129/* A forward reference `enum foo' when no enum named foo is defined yet
130   has zero (a null pointer) in its TYPE_SIZE.  The tag name is in
131   the TYPE_NAME field.  If the type is later defined, the normal
132   fields are filled in.
133   RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are
134   treated similarly.  */
135DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0)
136
137/* Boolean type (true or false are the only values).  Looks like an
138   INTEGRAL_TYPE.  */
139DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0)
140
141/* Integer types in all languages, including char in C.
142   Also used for sub-ranges of other discrete types.
143   Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive)
144   and TYPE_PRECISION (number of bits used by this type).
145   In the case of a subrange type in Pascal, the TREE_TYPE
146   of this will point at the supertype (another INTEGER_TYPE,
147   or an ENUMERAL_TYPE or BOOLEAN_TYPE).
148   Otherwise, the TREE_TYPE is zero.  */
149DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0)
150
151/* C's float and double.  Different floating types are distinguished
152   by machine mode and by the TYPE_SIZE and the TYPE_PRECISION.  */
153DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0)
154
155/* The ordering of the following codes is optimized for the checking
156   macros in tree.h.  Changing the order will degrade the speed of the
157   compiler.  POINTER_TYPE, REFERENCE_TYPE.  Note that this range
158   overlaps the previous range of ordered types.  */
159
160/* All pointer-to-x types have code POINTER_TYPE.
161   The TREE_TYPE points to the node for the type pointed to.  */
162DEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0)
163
164/* A reference is like a pointer except that it is coerced
165   automatically to the value it points to.  Used in C++.  */
166DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0)
167
168/* The C++ decltype(nullptr) type.  */
169DEFTREECODE (NULLPTR_TYPE, "nullptr_type", tcc_type, 0)
170
171/* _Fract and _Accum types in Embedded-C.  Different fixed-point types
172   are distinguished by machine mode and by the TYPE_SIZE and the
173   TYPE_PRECISION.  */
174DEFTREECODE (FIXED_POINT_TYPE, "fixed_point_type", tcc_type, 0)
175
176/* The ordering of the following codes is optimized for the checking
177   macros in tree.h.  Changing the order will degrade the speed of the
178   compiler.  COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE.  */
179
180/* Complex number types.  The TREE_TYPE field is the data type
181   of the real and imaginary parts.  It must be of scalar
182   arithmetic type, not including pointer type.  */
183DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0)
184
185/* Vector types.  The TREE_TYPE field is the data type of the vector
186   elements.  The TYPE_PRECISION field is the number of subparts of
187   the vector.  */
188DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0)
189
190/* The ordering of the following codes is optimized for the checking
191   macros in tree.h.  Changing the order will degrade the speed of the
192   compiler.  ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE.
193   Note that this range overlaps the previous range.  */
194
195/* Types of arrays.  Special fields:
196   TREE_TYPE              Type of an array element.
197   TYPE_DOMAIN            Type to index by.
198                            Its range of values specifies the array length.
199 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero
200 and holds the type to coerce a value of that array type to in C.
201 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars)
202 in languages (such as Chill) that make a distinction.  */
203/* Array types in C or Pascal */
204DEFTREECODE (ARRAY_TYPE, "array_type", tcc_type, 0)
205
206/* Struct in C, or record in Pascal.  */
207/* Special fields:
208   TYPE_FIELDS  chain of FIELD_DECLs for the fields of the struct,
209     and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables,
210     types and enumerators.
211   A few may need to be added for Pascal.  */
212/* See the comment above, before ENUMERAL_TYPE, for how
213   forward references to struct tags are handled in C.  */
214DEFTREECODE (RECORD_TYPE, "record_type", tcc_type, 0)
215
216/* Union in C.  Like a struct, except that the offsets of the fields
217   will all be zero.  */
218/* See the comment above, before ENUMERAL_TYPE, for how
219   forward references to union tags are handled in C.  */
220DEFTREECODE (UNION_TYPE, "union_type", tcc_type, 0)     /* C union type */
221
222/* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER
223   in each FIELD_DECL determine what the union contains.  The first
224   field whose DECL_QUALIFIER expression is true is deemed to occupy
225   the union.  */
226DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0)
227
228/* The ordering of the following codes is optimized for the checking
229   macros in tree.h.  Changing the order will degrade the speed of the
230   compiler.  VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE.  */
231
232/* The void type in C */
233DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0)
234
235/* Type of functions.  Special fields:
236   TREE_TYPE                type of value returned.
237   TYPE_ARG_TYPES      list of types of arguments expected.
238        this list is made of TREE_LIST nodes.
239   Types of "Procedures" in languages where they are different from functions
240   have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type.  */
241DEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0)
242
243/* METHOD_TYPE is the type of a function which takes an extra first
244   argument for "self", which is not present in the declared argument list.
245   The TREE_TYPE is the return type of the method.  The TYPE_METHOD_BASETYPE
246   is the type of "self".  TYPE_ARG_TYPES is the real argument list, which
247   includes the hidden argument for "self".  */
248DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0)
249
250/* This is a language-specific kind of type.
251   Its meaning is defined by the language front end.
252   layout_type does not know how to lay this out,
253   so the front-end must do so manually.  */
254DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0)
255
256/* Expressions */
257
258/* First, the constants.  */
259
260/* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields,
261   32 bits each, giving us a 64 bit constant capability.  INTEGER_CST
262   nodes can be shared, and therefore should be considered read only.
263   They should be copied, before setting a flag such as TREE_OVERFLOW.
264   If an INTEGER_CST has TREE_OVERFLOW already set, it is known to be unique.
265   INTEGER_CST nodes are created for the integral types, for pointer
266   types and for vector and float types in some circumstances.  */
267DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0)
268
269/* Contents are in TREE_REAL_CST field.  */
270DEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0)
271
272/* Contents are in TREE_FIXED_CST field.  */
273DEFTREECODE (FIXED_CST, "fixed_cst", tcc_constant, 0)
274
275/* Contents are in TREE_REALPART and TREE_IMAGPART fields,
276   whose contents are other constant nodes.  */
277DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0)
278
279/* Contents are in TREE_VECTOR_CST_ELTS field.  */
280DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0)
281
282/* Contents are TREE_STRING_LENGTH and the actual contents of the string.  */
283DEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0)
284
285/* Declarations.  All references to names are represented as ..._DECL
286   nodes.  The decls in one binding context are chained through the
287   TREE_CHAIN field.  Each DECL has a DECL_NAME field which contains
288   an IDENTIFIER_NODE.  (Some decls, most often labels, may have zero
289   as the DECL_NAME).  DECL_CONTEXT points to the node representing
290   the context in which this declaration has its scope.  For
291   FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or
292   QUAL_UNION_TYPE node that the field is a member of.  For VAR_DECL,
293   PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this
294   points to either the FUNCTION_DECL for the containing function, the
295   RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or
296   a TRANSLATION_UNIT_DECL if the given decl has "file scope".
297   DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract)
298    ..._DECL node of which this decl is an (inlined or template expanded)
299    instance.
300   The TREE_TYPE field holds the data type of the object, when relevant.
301    LABEL_DECLs have no data type.  For TYPE_DECL, the TREE_TYPE field
302    contents are the type whose name is being declared.
303   The DECL_ALIGN, DECL_SIZE,
304    and DECL_MODE fields exist in decl nodes just as in type nodes.
305    They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes.
306
307   DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for
308   the location.  DECL_VOFFSET holds an expression for a variable
309   offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer).
310   These fields are relevant only in FIELD_DECLs and PARM_DECLs.
311
312   DECL_INITIAL holds the value to initialize a variable to,
313   or the value of a constant.  For a function, it holds the body
314   (a node of type BLOCK representing the function's binding contour
315   and whose body contains the function's statements.)  For a LABEL_DECL
316   in C, it is a flag, nonzero if the label's definition has been seen.
317
318   PARM_DECLs use a special field:
319   DECL_ARG_TYPE is the type in which the argument is actually
320    passed, which may be different from its type within the function.
321
322   FUNCTION_DECLs use four special fields:
323   DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments.
324   DECL_RESULT holds a RESULT_DECL node for the value of a function.
325    The DECL_RTL field is 0 for a function that returns no value.
326    (C functions returning void have zero here.)
327    The TREE_TYPE field is the type in which the result is actually
328    returned.  This is usually the same as the return type of the
329    FUNCTION_DECL, but it may be a wider integer type because of
330    promotion.
331   DECL_FUNCTION_CODE is a code number that is nonzero for
332    built-in functions.  Its value is an enum built_in_function
333    that says which built-in function it is.
334
335   DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE
336   holds a line number.  In some cases these can be the location of
337   a reference, if no definition has been seen.
338
339   DECL_ABSTRACT is nonzero if the decl represents an abstract instance
340   of a decl (i.e. one which is nested within an abstract instance of a
341   inline function.  */
342
343DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0)
344DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0)
345/* The ordering of the following codes is optimized for the checking
346   macros in tree.h.  Changing the order will degrade the speed of the
347   compiler.  FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL,
348   TYPE_DECL.  */
349DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0)
350DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0)
351DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0)
352DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0)
353DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0)
354DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0)
355
356/* A "declaration" of a debug temporary.  It should only appear in
357   DEBUG stmts.  */
358DEFTREECODE (DEBUG_EXPR_DECL, "debug_expr_decl", tcc_declaration, 0)
359
360/* A namespace declaration.  Namespaces appear in DECL_CONTEXT of other
361   _DECLs, providing a hierarchy of names.  */
362DEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0)
363
364/* A declaration import.
365   The C++ FE uses this to represent a using-directive; eg:
366   "using namespace foo".
367   But it could be used to represent any declaration import construct.
368   Whenever a declaration import appears in a lexical block, the BLOCK node
369   representing that lexical block in GIMPLE will contain an IMPORTED_DECL
370   node, linked via BLOCK_VARS accessor of the said BLOCK.
371   For a given NODE which code is IMPORTED_DECL,
372   IMPORTED_DECL_ASSOCIATED_DECL (NODE) accesses the imported declaration.  */
373DEFTREECODE (IMPORTED_DECL, "imported_decl", tcc_declaration, 0)
374
375/* A namelist declaration.
376   The Fortran FE uses this to represent a namelist statement, e.g.:
377   NAMELIST /namelist-group-name/ namelist-group-object-list.
378   Whenever a declaration import appears in a lexical block, the BLOCK node
379   representing that lexical block in GIMPLE will contain an NAMELIST_DECL
380   node, linked via BLOCK_VARS accessor of the said BLOCK.
381   For a given NODE which code is NAMELIST_DECL,
382   NAMELIST_DECL_ASSOCIATED_DECL (NODE) accesses the imported declaration.  */
383DEFTREECODE (NAMELIST_DECL, "namelist_decl", tcc_declaration, 0)
384
385/* A translation unit.  This is not technically a declaration, since it
386   can't be looked up, but it's close enough.  */
387DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\
388             tcc_declaration, 0)
389
390/* References to storage.  */
391
392/* The ordering of the following codes is optimized for the classification
393   in handled_component_p.  Keep them in a consecutive group.  */
394
395/* Value is structure or union component.
396   Operand 0 is the structure or union (an expression).
397   Operand 1 is the field (a node of type FIELD_DECL).
398   Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured
399   in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT.  */
400DEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3)
401
402/* Reference to a group of bits within an object.  Similar to COMPONENT_REF
403   except the position is given explicitly rather than via a FIELD_DECL.
404   Operand 0 is the structure or union expression;
405   operand 1 is a tree giving the constant number of bits being referenced;
406   operand 2 is a tree giving the constant position of the first referenced bit.
407   The result type width has to match the number of bits referenced.
408   If the result type is integral, its signedness specifies how it is extended
409   to its mode width.  */
410DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3)
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.  */
417DEFTREECODE (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.  */
422DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4)
423
424/* Used only on an operand of complex type, these return
425   a value of the corresponding component type.  */
426DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1)
427DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1)
428
429/* Represents viewing something of one type as being of a second type.
430   This corresponds to an "Unchecked Conversion" in Ada and roughly to
431   the idiom *(type2 *)&X in C.  The only operand is the value to be
432   viewed as being of another type.  It is undefined if the type of the
433   input and of the expression have different sizes.
434
435   This code may also be used within the LHS of a MODIFY_EXPR, in which
436   case no actual data motion may occur.  TREE_ADDRESSABLE will be set in
437   this case and GCC must abort if it could not do the operation without
438   generating insns.  */
439DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1)
440
441/* C unary `*' or Pascal `^'.  One operand, an expression for a pointer.  */
442DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1)
443
444/* Used to represent lookup in a virtual method table which is dependent on
445   the runtime type of an object.  Operands are:
446   OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use.
447   OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is
448   being performed.  Through this the optimizers may be able to statically
449   determine the dynamic type of the object.
450   OBJ_TYPE_REF_TOKEN: An integer index to the virtual method table.  */
451DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3)
452
453/* Used to represent the brace-enclosed initializers for a structure or an
454   array.  It contains a sequence of component values made out of a VEC of
455   constructor_elt.
456
457   For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE:
458   The field INDEX of each constructor_elt is a FIELD_DECL.
459
460   For ARRAY_TYPE:
461   The field INDEX of each constructor_elt is the corresponding index.
462   If the index is a RANGE_EXPR, it is a short-hand for many nodes,
463   one for each index in the range.  (If the corresponding field VALUE
464   has side-effects, they are evaluated once for each element.  Wrap the
465   value in a SAVE_EXPR if you want to evaluate side effects only once.)
466
467   Components that aren't present are cleared as per the C semantics,
468   unless the CONSTRUCTOR_NO_CLEARING flag is set, in which case their
469   value becomes undefined.  */
470DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0)
471
472/* The expression types are mostly straightforward, with the fourth argument
473   of DEFTREECODE saying how many operands there are.
474   Unless otherwise specified, the operands are expressions and the
475   types of all the operands and the expression must all be the same.  */
476
477/* Contains two expressions to compute, one followed by the other.
478   the first value is ignored.  The second one's value is used.  The
479   type of the first expression need not agree with the other types.  */
480DEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2)
481
482/* Assignment expression.  Operand 0 is the what to set; 1, the new value.  */
483DEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2)
484
485/* Initialization expression.  Operand 0 is the variable to initialize;
486   Operand 1 is the initializer.  This differs from MODIFY_EXPR in that any
487   reference to the referent of operand 0 within operand 1 is undefined.  */
488DEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2)
489
490/* For TARGET_EXPR, operand 0 is the target of an initialization,
491   operand 1 is the initializer for the target, which may be void
492     if simply expanding it initializes the target.
493   operand 2 is the cleanup for this node, if any.
494   operand 3 is the saved initializer after this node has been
495   expanded once; this is so we can re-expand the tree later.  */
496DEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4)
497
498/* Conditional expression ( ... ? ... : ...  in C).
499   Operand 0 is the condition.
500   Operand 1 is the then-value.
501   Operand 2 is the else-value.
502   Operand 0 may be of any type.
503   Operand 1 must have the same type as the entire expression, unless
504   it unconditionally throws an exception, in which case it should
505   have VOID_TYPE.  The same constraints apply to operand 2.  The
506   condition in operand 0 must be of integral type.
507
508   In cfg gimple, if you do not have a selection expression, operands
509   1 and 2 are NULL.  The operands are then taken from the cfg edges. */
510DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3)
511
512/* Vector conditional expression. It is like COND_EXPR, but with
513   vector operands.
514
515   A = VEC_COND_EXPR ( X < Y, B, C)
516
517   means
518
519   for (i=0; i<N; i++)
520     A[i] = X[i] < Y[i] ? B[i] : C[i];
521*/
522DEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3)
523
524/* Vector permutation expression.  A = VEC_PERM_EXPR<v0, v1, mask> means
525
526   N = length(mask)
527   foreach i in N:
528     M = mask[i] % (2*N)
529     A = M < N ? v0[M] : v1[M-N]
530
531   V0 and V1 are vectors of the same type.  MASK is an integer-typed
532   vector.  The number of MASK elements must be the same with the
533   number of elements in V0 and V1.  The size of the inner type
534   of the MASK and of the V0 and V1 must be the same.
535*/
536DEFTREECODE (VEC_PERM_EXPR, "vec_perm_expr", tcc_expression, 3)
537
538/* Declare local variables, including making RTL and allocating space.
539   BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables.
540   BIND_EXPR_BODY is the body, the expression to be computed using
541   the variables.  The value of operand 1 becomes that of the BIND_EXPR.
542   BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings
543   for debugging purposes.  If this BIND_EXPR is actually expanded,
544   that sets the TREE_USED flag in the BLOCK.
545
546   The BIND_EXPR is not responsible for informing parsers
547   about these variables.  If the body is coming from the input file,
548   then the code that creates the BIND_EXPR is also responsible for
549   informing the parser of the variables.
550
551   If the BIND_EXPR is ever expanded, its TREE_USED flag is set.
552   This tells the code for debugging symbol tables not to ignore the BIND_EXPR.
553   If the BIND_EXPR should be output for debugging but will not be expanded,
554   set the TREE_USED flag by hand.
555
556   In order for the BIND_EXPR to be known at all, the code that creates it
557   must also install it as a subblock in the tree of BLOCK
558   nodes for the function.  */
559DEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3)
560
561/* Function call.  CALL_EXPRs are represented by variably-sized expression
562   nodes.  There are at least three fixed operands.  Operand 0 is an
563   INTEGER_CST node containing the total operand count, the number of
564   arguments plus 3.  Operand 1 is the function, while operand 2 is
565   is static chain argument, or NULL.  The remaining operands are the
566   arguments to the call.  */
567DEFTREECODE (CALL_EXPR, "call_expr", tcc_vl_exp, 3)
568
569/* Specify a value to compute along with its corresponding cleanup.
570   Operand 0 is the cleanup expression.
571   The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR,
572   which must exist.  This differs from TRY_CATCH_EXPR in that operand 1
573   is always evaluated when cleanups are run.  */
574DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1)
575
576/* Specify a cleanup point.
577   Operand 0 is an expression that may have cleanups.  If it does, those
578   cleanups are executed after the expression is expanded.
579
580   Note that if the expression is a reference to storage, it is forced out
581   of memory before the cleanups are run.  This is necessary to handle
582   cases where the cleanups modify the storage referenced; in the
583   expression 't.i', if 't' is a struct with an integer member 'i' and a
584   cleanup which modifies 'i', the value of the expression depends on
585   whether the cleanup is run before or after 't.i' is evaluated.  When
586   expand_expr is run on 't.i', it returns a MEM.  This is not good enough;
587   the value of 't.i' must be forced out of memory.
588
589   As a consequence, the operand of a CLEANUP_POINT_EXPR must not have
590   BLKmode, because it will not be forced out of memory.  */
591DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1)
592
593/* The following code is used in languages that have types where some
594   field in an object of the type contains a value that is used in the
595   computation of another field's offset or size and/or the size of the
596   type.  The positions and/or sizes of fields can vary from object to
597   object of the same type or even for one and the same object within
598   its scope.
599
600   Record types with discriminants in Ada or schema types in Pascal are
601   examples of such types.  This mechanism is also used to create "fat
602   pointers" for unconstrained array types in Ada; the fat pointer is a
603   structure one of whose fields is a pointer to the actual array type
604   and the other field is a pointer to a template, which is a structure
605   containing the bounds of the array.  The bounds in the type pointed
606   to by the first field in the fat pointer refer to the values in the
607   template.
608
609   When you wish to construct such a type you need "self-references"
610   that allow you to reference the object having this type from the
611   TYPE node, i.e. without having a variable instantiating this type.
612
613   Such a "self-references" is done using a PLACEHOLDER_EXPR.  This is
614   a node that will later be replaced with the object being referenced.
615   Its type is that of the object and selects which object to use from
616   a chain of references (see below).  No other slots are used in the
617   PLACEHOLDER_EXPR.
618
619   For example, if your type FOO is a RECORD_TYPE with a field BAR,
620   and you need the value of <variable>.BAR to calculate TYPE_SIZE
621   (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR
622   whose TREE_TYPE is FOO.  Then construct your COMPONENT_REF with
623   the PLACEHOLDER_EXPR as the first operand (which has the correct
624   type).  Later, when the size is needed in the program, the back-end
625   will find this PLACEHOLDER_EXPR and generate code to calculate the
626   actual size at run-time.  In the following, we describe how this
627   calculation is done.
628
629   When we wish to evaluate a size or offset, we check whether it contains a
630   PLACEHOLDER_EXPR.  If it does, we call substitute_placeholder_in_expr
631   passing both that tree and an expression within which the object may be
632   found.  The latter expression is the object itself in the simple case of
633   an Ada record with discriminant, but it can be the array in the case of an
634   unconstrained array.
635
636   In the latter case, we need the fat pointer, because the bounds of
637   the array can only be accessed from it.  However, we rely here on the
638   fact that the expression for the array contains the dereference of
639   the fat pointer that obtained the array pointer.  */
640
641/* Denotes a record to later be substituted before evaluating this expression.
642   The type of this expression is used to find the record to replace it.  */
643DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0)
644
645/* Simple arithmetic.  */
646DEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2)
647DEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2)
648DEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2)
649
650/* Pointer addition.  The first operand is always a pointer and the
651   second operand is an integer of type sizetype.  */
652DEFTREECODE (POINTER_PLUS_EXPR, "pointer_plus_expr", tcc_binary, 2)
653
654/* Highpart multiplication.  For an integral type with precision B,
655   returns bits [2B-1, B] of the full 2*B product.  */
656DEFTREECODE (MULT_HIGHPART_EXPR, "mult_highpart_expr", tcc_binary, 2)
657
658/* Division for integer result that rounds the quotient toward zero.  */
659DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2)
660
661/* Division for integer result that rounds the quotient toward infinity.  */
662DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2)
663
664/* Division for integer result that rounds toward minus infinity.  */
665DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2)
666
667/* Division for integer result that rounds toward nearest integer.  */
668DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2)
669
670/* Four kinds of remainder that go with the four kinds of division.  */
671DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2)
672DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2)
673DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2)
674DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2)
675
676/* Division for real result.  */
677DEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2)
678
679/* Division which is not supposed to need rounding.
680   Used for pointer subtraction in C.  */
681DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2)
682
683/* Conversion of real to fixed point by truncation.  */
684DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1)
685
686/* Conversion of an integer to a real.  */
687DEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1)
688
689/* Unary negation.  */
690DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1)
691
692/* Minimum and maximum values.  When used with floating point, if both
693   operands are zeros, or if either operand is NaN, then it is unspecified
694   which of the two operands is returned as the result.  */
695DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2)
696DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2)
697
698/* Represents the absolute value of the operand.
699
700   An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE.  The
701   operand of the ABS_EXPR must have the same type.  */
702DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1)
703
704/* Shift operations for shift and rotate.
705   Shift means logical shift if done on an
706   unsigned type, arithmetic shift if done on a signed type.
707   The second operand is the number of bits to
708   shift by; it need not be the same type as the first operand and result.
709   Note that the result is undefined if the second operand is larger
710   than or equal to the first operand's type size.
711
712   The first operand of a shift can have either an integer or a
713   (non-integer) fixed-point type.  We follow the ISO/IEC TR 18037:2004
714   semantics for the latter.
715
716   Rotates are defined for integer types only.  */
717DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2)
718DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2)
719DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2)
720DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2)
721
722/* Bitwise operations.  Operands have same mode as result.  */
723DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2)
724DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2)
725DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2)
726DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1)
727
728/* ANDIF and ORIF allow the second operand not to be computed if the
729   value of the expression is determined from the first operand.  AND,
730   OR, and XOR always compute the second operand whether its value is
731   needed or not (for side effects).  The operand may have
732   BOOLEAN_TYPE or INTEGER_TYPE.  In either case, the argument will be
733   either zero or one.  For example, a TRUTH_NOT_EXPR will never have
734   an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be
735   used to compare the VAR_DECL to zero, thereby obtaining a node with
736   value zero or one.  */
737DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2)
738DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2)
739DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2)
740DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2)
741DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2)
742DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1)
743
744/* Relational operators.
745   `EQ_EXPR' and `NE_EXPR' are allowed for any types.
746   The others are allowed only for integer (or pointer or enumeral)
747   or real types.
748   In all cases the operands will have the same type,
749   and the value is either the type used by the language for booleans
750   or an integer vector type of the same size and with the same number
751   of elements as the comparison operands.  True for a vector of
752   comparison results has all bits set while false is equal to zero.  */
753DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2)
754DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2)
755DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2)
756DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2)
757DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2)
758DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2)
759
760/* Additional relational operators for floating point unordered.  */
761DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2)
762DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2)
763
764/* These are equivalent to unordered or ...  */
765DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2)
766DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2)
767DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2)
768DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2)
769DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2)
770
771/* This is the reverse of uneq_expr.  */
772DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2)
773
774DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2)
775
776/* Represents a re-association barrier for floating point expressions
777   like explicit parenthesis in fortran.  */
778DEFTREECODE (PAREN_EXPR, "paren_expr", tcc_unary, 1)
779
780/* Represents a conversion of type of a value.
781   All conversions, including implicit ones, must be
782   represented by CONVERT_EXPR or NOP_EXPR nodes.  */
783DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1)
784
785/* Conversion of a pointer value to a pointer to a different
786   address space.  */
787DEFTREECODE (ADDR_SPACE_CONVERT_EXPR, "addr_space_convert_expr", tcc_unary, 1)
788
789/* Conversion of a fixed-point value to an integer, a real, or a fixed-point
790   value.  Or conversion of a fixed-point value from an integer, a real, or
791   a fixed-point value.  */
792DEFTREECODE (FIXED_CONVERT_EXPR, "fixed_convert_expr", tcc_unary, 1)
793
794/* Represents a conversion expected to require no code to be generated.  */
795DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1)
796
797/* Value is same as argument, but guaranteed not an lvalue.  */
798DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1)
799
800/* A COMPOUND_LITERAL_EXPR represents a literal that is placed in a DECL.  The
801   COMPOUND_LITERAL_EXPR_DECL_EXPR is the a DECL_EXPR containing the decl
802   for the anonymous object represented by the COMPOUND_LITERAL;
803   the DECL_INITIAL of that decl is the CONSTRUCTOR that initializes
804   the compound literal.  */
805DEFTREECODE (COMPOUND_LITERAL_EXPR, "compound_literal_expr", tcc_expression, 1)
806
807/* Represents something we computed once and will use multiple times.
808   First operand is that expression.  After it is evaluated once, it
809   will be replaced by the temporary variable that holds the value.  */
810DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1)
811
812/* & in C.  Value is the address at which the operand's value resides.
813   Operand may have any mode.  Result mode is Pmode.  */
814DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1)
815
816/* Operand0 is a function constant; result is part N of a function
817   descriptor of type ptr_mode.  */
818DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2)
819
820/* Given two real or integer operands of the same type,
821   returns a complex value of the corresponding complex type.  */
822DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2)
823
824/* Complex conjugate of operand.  Used only on complex types.  */
825DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1)
826
827/* Nodes for ++ and -- in C.
828   The second arg is how much to increment or decrement by.
829   For a pointer, it would be the size of the object pointed to.  */
830DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2)
831DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2)
832DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2)
833DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2)
834
835/* Used to implement `va_arg'.  */
836DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1)
837
838/* Evaluate operand 1.  If and only if an exception is thrown during
839   the evaluation of operand 1, evaluate operand 2.
840
841   This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated
842   on a normal or jump exit, only on an exception.  */
843DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2)
844
845/* Evaluate the first operand.
846   The second operand is a cleanup expression which is evaluated
847   on any exit (normal, exception, or jump out) from this expression.  */
848DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2)
849
850/* These types of expressions have no useful value,
851   and always have side effects.  */
852
853/* Used to represent a local declaration. The operand is DECL_EXPR_DECL.  */
854DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1)
855
856/* A label definition, encapsulated as a statement.
857   Operand 0 is the LABEL_DECL node for the label that appears here.
858   The type should be void and the value should be ignored.  */
859DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1)
860
861/* GOTO.  Operand 0 is a LABEL_DECL node or an expression.
862   The type should be void and the value should be ignored.  */
863DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1)
864
865/* RETURN.  Evaluates operand 0, then returns from the current function.
866   Presumably that operand is an assignment that stores into the
867   RESULT_DECL that hold the value to be returned.
868   The operand may be null.
869   The type should be void and the value should be ignored.  */
870DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1)
871
872/* Exit the inner most loop conditionally.  Operand 0 is the condition.
873   The type should be void and the value should be ignored.  */
874DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1)
875
876/* A loop.  Operand 0 is the body of the loop.
877   It must contain an EXIT_EXPR or is an infinite loop.
878   The type should be void and the value should be ignored.  */
879DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1)
880
881/* Switch expression.
882
883   TREE_TYPE is the original type of the condition, before any
884   language required type conversions.  It may be NULL, in which case
885   the original type and final types are assumed to be the same.
886
887   Operand 0 is the expression used to perform the branch,
888   Operand 1 is the body of the switch, which probably contains
889     CASE_LABEL_EXPRs.  It may also be NULL, in which case operand 2
890     must not be NULL.
891   Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs
892     of all the cases.  */
893DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3)
894
895/* Used to represent a case label.
896
897   Operand 0 is CASE_LOW.  It may be NULL_TREE, in which case the label
898     is a 'default' label.
899   Operand 1 is CASE_HIGH.  If it is NULL_TREE, the label is a simple
900     (one-value) case label.  If it is non-NULL_TREE, the case is a range.
901   Operand 2 is CASE_LABEL, which is is the corresponding LABEL_DECL.
902   Operand 4 is CASE_CHAIN.  This operand is only used in tree-cfg.c to
903     speed up the lookup of case labels which use a particular edge in
904     the control flow graph.  */
905DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 4)
906
907/* Used to represent an inline assembly statement.  ASM_STRING returns a
908   STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS,
909   ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers
910   for the statement.  ASM_LABELS, if present, indicates various destinations
911   for the asm; labels cannot be combined with outputs.  */
912DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 5)
913
914/* Variable references for SSA analysis.  New SSA names are created every
915   time a variable is assigned a new value.  The SSA builder uses SSA_NAME
916   nodes to implement SSA versioning.  */
917DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0)
918
919/* Used to represent a typed exception handler.  CATCH_TYPES is the type (or
920   list of types) handled, and CATCH_BODY is the code for the handler.  */
921DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2)
922
923/* Used to represent an exception specification.  EH_FILTER_TYPES is a list
924   of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on
925   failure.  */
926DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2)
927
928/* Node used for describing a property that is known at compile
929   time.  */
930DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0)
931
932/* Node used for describing a property that is not known at compile
933   time.  */
934DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0)
935
936/* Polynomial chains of recurrences.
937   Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}.  */
938DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3)
939
940/* Used to chain children of container statements together.
941   Use the interface in tree-iterator.h to access this node.  */
942DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0)
943
944/* Predicate assertion.  Artificial expression generated by the optimizers
945   to keep track of predicate values.  This expression may only appear on
946   the RHS of assignments.
947
948   Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer
949   two things:
950
951        1- X is a copy of Y.
952        2- EXPR is a conditional expression and is known to be true.
953
954   Valid and to be expected forms of conditional expressions are
955   valid GIMPLE conditional expressions (as defined by is_gimple_condexpr)
956   and conditional expressions with the first operand being a
957   PLUS_EXPR with a variable possibly wrapped in a NOP_EXPR first
958   operand and an integer constant second operand.
959
960   The type of the expression is the same as Y.  */
961DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2)
962
963/* Base class information. Holds information about a class as a
964   baseclass of itself or another class.  */
965DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0)
966
967/* Records the size for an expression of variable size type.  This is
968   for use in contexts in which we are accessing the entire object,
969   such as for a function call, or block copy.
970   Operand 0 is the real expression.
971   Operand 1 is the size of the type in the expression.  */
972DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2)
973
974/* Extract elements from two input vectors Operand 0 and Operand 1
975   size VS, according to the offset OFF defined by Operand 2 as
976   follows:
977   If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to
978   the first OFF elements of the vector OP1.
979   If OFF == 0, then the returned vector is OP1.
980   On different targets OFF may take different forms; It can be an address, in
981   which case its low log2(VS)-1 bits define the offset, or it can be a mask
982   generated by the builtin targetm.vectorize.mask_for_load_builtin_decl.  */
983DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3)
984
985/* Low-level memory addressing.  Operands are BASE (address of static or
986   global variable or register), OFFSET (integer constant),
987   INDEX (register), STEP (integer constant), INDEX2 (register),
988   The corresponding address is BASE + STEP * INDEX + INDEX2 + OFFSET.
989   Only variations and values valid on the target are allowed.
990
991   The type of STEP, INDEX and INDEX2 is sizetype.
992
993   The type of BASE is a pointer type.  If BASE is not an address of
994   a static or global variable INDEX2 will be NULL.
995
996   The type of OFFSET is a pointer type and determines TBAA the same as
997   the constant offset operand in MEM_REF.  */
998
999DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 5)
1000
1001/* Memory addressing.  Operands are a pointer and a tree constant integer
1002   byte offset of the pointer type that when dereferenced yields the
1003   type of the base object the pointer points into and which is used for
1004   TBAA purposes.
1005   The type of the MEM_REF is the type the bytes at the memory location
1006   are interpreted as.
1007   MEM_REF <p, c> is equivalent to ((typeof(c))p)->x... where x... is a
1008   chain of component references offsetting p by c.  */
1009DEFTREECODE (MEM_REF, "mem_ref", tcc_reference, 2)
1010
1011/* The ordering of the codes between OMP_PARALLEL and OMP_CRITICAL is
1012   exposed to TREE_RANGE_CHECK.  */
1013/* OpenMP - #pragma omp parallel [clause1 ... clauseN]
1014   Operand 0: OMP_PARALLEL_BODY: Code to be executed by all threads.
1015   Operand 1: OMP_PARALLEL_CLAUSES: List of clauses.  */
1016
1017DEFTREECODE (OMP_PARALLEL, "omp_parallel", tcc_statement, 2)
1018
1019/* OpenMP - #pragma omp task [clause1 ... clauseN]
1020   Operand 0: OMP_TASK_BODY: Code to be executed by all threads.
1021   Operand 1: OMP_TASK_CLAUSES: List of clauses.  */
1022
1023DEFTREECODE (OMP_TASK, "omp_task", tcc_statement, 2)
1024
1025/* OpenMP - #pragma omp for [clause1 ... clauseN]
1026   Operand 0: OMP_FOR_BODY: Loop body.
1027   Operand 1: OMP_FOR_CLAUSES: List of clauses.
1028   Operand 2: OMP_FOR_INIT: Initialization code of the form
1029                                VAR = N1.
1030   Operand 3: OMP_FOR_COND: Loop conditional expression of the form
1031                                VAR { <, >, <=, >= } N2.
1032   Operand 4: OMP_FOR_INCR: Loop index increment of the form
1033                                VAR { +=, -= } INCR.
1034   Operand 5: OMP_FOR_PRE_BODY: Filled by the gimplifier with things
1035        from INIT, COND, and INCR that are technically part of the
1036        OMP_FOR structured block, but are evaluated before the loop
1037        body begins.
1038
1039   VAR must be an integer or pointer variable, which is implicitly thread
1040   private.  N1, N2 and INCR are required to be loop invariant integer
1041   expressions that are evaluated without any synchronization.
1042   The evaluation order, frequency of evaluation and side-effects are
1043   unspecified by the standard.  */
1044DEFTREECODE (OMP_FOR, "omp_for", tcc_statement, 6)
1045
1046/* OpenMP - #pragma omp simd [clause1 ... clauseN]
1047   Operands like for OMP_FOR.  */
1048DEFTREECODE (OMP_SIMD, "omp_simd", tcc_statement, 6)
1049
1050/* Cilk Plus - #pragma simd [clause1 ... clauseN]
1051   Operands like for OMP_FOR.  */
1052DEFTREECODE (CILK_SIMD, "cilk_simd", tcc_statement, 6)
1053
1054/* OpenMP - #pragma omp distribute [clause1 ... clauseN]
1055   Operands like for OMP_FOR.  */
1056DEFTREECODE (OMP_DISTRIBUTE, "omp_distribute", tcc_statement, 6)
1057
1058/* OpenMP - #pragma omp teams [clause1 ... clauseN]
1059   Operand 0: OMP_TEAMS_BODY: Teams body.
1060   Operand 1: OMP_TEAMS_CLAUSES: List of clauses.  */
1061DEFTREECODE (OMP_TEAMS, "omp_teams", tcc_statement, 2)
1062
1063/* OpenMP - #pragma omp target data [clause1 ... clauseN]
1064   Operand 0: OMP_TARGET_DATA_BODY: Target data construct body.
1065   Operand 1: OMP_TARGET_DATA_CLAUSES: List of clauses.  */
1066DEFTREECODE (OMP_TARGET_DATA, "omp_target_data", tcc_statement, 2)
1067
1068/* OpenMP - #pragma omp target [clause1 ... clauseN]
1069   Operand 0: OMP_TARGET_BODY: Target construct body.
1070   Operand 1: OMP_TARGET_CLAUSES: List of clauses.  */
1071DEFTREECODE (OMP_TARGET, "omp_target", tcc_statement, 2)
1072
1073/* OpenMP - #pragma omp sections [clause1 ... clauseN]
1074   Operand 0: OMP_SECTIONS_BODY: Sections body.
1075   Operand 1: OMP_SECTIONS_CLAUSES: List of clauses.  */
1076DEFTREECODE (OMP_SECTIONS, "omp_sections", tcc_statement, 2)
1077
1078/* OpenMP - #pragma omp single
1079   Operand 0: OMP_SINGLE_BODY: Single section body.
1080   Operand 1: OMP_SINGLE_CLAUSES: List of clauses.  */
1081DEFTREECODE (OMP_SINGLE, "omp_single", tcc_statement, 2)
1082
1083/* OpenMP - #pragma omp section
1084   Operand 0: OMP_SECTION_BODY: Section body.  */
1085DEFTREECODE (OMP_SECTION, "omp_section", tcc_statement, 1)
1086
1087/* OpenMP - #pragma omp master
1088   Operand 0: OMP_MASTER_BODY: Master section body.  */
1089DEFTREECODE (OMP_MASTER, "omp_master", tcc_statement, 1)
1090
1091/* OpenMP - #pragma omp taskgroup
1092   Operand 0: OMP_TASKGROUP_BODY: Taskgroup body.  */
1093DEFTREECODE (OMP_TASKGROUP, "omp_taskgroup", tcc_statement, 1)
1094
1095/* OpenMP - #pragma omp ordered
1096   Operand 0: OMP_ORDERED_BODY: Master section body.  */
1097DEFTREECODE (OMP_ORDERED, "omp_ordered", tcc_statement, 1)
1098
1099/* OpenMP - #pragma omp critical [name]
1100   Operand 0: OMP_CRITICAL_BODY: Critical section body.
1101   Operand 1: OMP_CRITICAL_NAME: Identifier for critical section.  */
1102DEFTREECODE (OMP_CRITICAL, "omp_critical", tcc_statement, 2)
1103
1104/* OpenMP - #pragma omp target update [clause1 ... clauseN]
1105   Operand 0: OMP_TARGET_UPDATE_CLAUSES: List of clauses.  */
1106DEFTREECODE (OMP_TARGET_UPDATE, "omp_target_update", tcc_statement, 1)
1107
1108/* OMP_ATOMIC through OMP_ATOMIC_CAPTURE_NEW must be consecutive,
1109   or OMP_ATOMIC_SEQ_CST needs adjusting.  */
1110
1111/* OpenMP - #pragma omp atomic
1112   Operand 0: The address at which the atomic operation is to be performed.
1113        This address should be stabilized with save_expr.
1114   Operand 1: The expression to evaluate.  When the old value of the object
1115        at the address is used in the expression, it should appear as if
1116        build_fold_indirect_ref of the address.  */
1117DEFTREECODE (OMP_ATOMIC, "omp_atomic", tcc_statement, 2)
1118
1119/* OpenMP - #pragma omp atomic read
1120   Operand 0: The address at which the atomic operation is to be performed.
1121        This address should be stabilized with save_expr.  */
1122DEFTREECODE (OMP_ATOMIC_READ, "omp_atomic_read", tcc_statement, 1)
1123
1124/* OpenMP - #pragma omp atomic capture
1125   Operand 0: The address at which the atomic operation is to be performed.
1126        This address should be stabilized with save_expr.
1127   Operand 1: The expression to evaluate.  When the old value of the object
1128        at the address is used in the expression, it should appear as if
1129        build_fold_indirect_ref of the address.
1130   OMP_ATOMIC_CAPTURE_OLD returns the old memory content,
1131   OMP_ATOMIC_CAPTURE_NEW the new value.  */
1132DEFTREECODE (OMP_ATOMIC_CAPTURE_OLD, "omp_atomic_capture_old", tcc_statement, 2)
1133DEFTREECODE (OMP_ATOMIC_CAPTURE_NEW, "omp_atomic_capture_new", tcc_statement, 2)
1134
1135/* OpenMP clauses.  */
1136DEFTREECODE (OMP_CLAUSE, "omp_clause", tcc_exceptional, 0)
1137
1138/* TRANSACTION_EXPR tree code.
1139   Operand 0: BODY: contains body of the transaction.  */
1140DEFTREECODE (TRANSACTION_EXPR, "transaction_expr", tcc_expression, 1)
1141
1142/* Reduction operations.
1143   Operations that take a vector of elements and "reduce" it to a scalar
1144   result (e.g. summing the elements of the vector, finding the minimum over
1145   the vector elements, etc).
1146   Operand 0 is a vector.
1147   The expression returns a vector of the same type, with the first
1148   element in the vector holding the result of the reduction of all elements
1149   of the operand.  The content of the other elements in the returned vector
1150   is undefined.  */
1151DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1)
1152DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1)
1153DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1)
1154
1155/* Widening dot-product.
1156   The first two arguments are of type t1.
1157   The third argument and the result are of type t2, such that t2 is at least
1158   twice the size of t1. DOT_PROD_EXPR(arg1,arg2,arg3) is equivalent to:
1159        tmp = WIDEN_MULT_EXPR(arg1, arg2);
1160        arg3 = PLUS_EXPR (tmp, arg3);
1161   or:
1162        tmp = WIDEN_MULT_EXPR(arg1, arg2);
1163        arg3 = WIDEN_SUM_EXPR (tmp, arg3);               */
1164DEFTREECODE (DOT_PROD_EXPR, "dot_prod_expr", tcc_expression, 3)
1165
1166/* Widening summation.
1167   The first argument is of type t1.
1168   The second argument is of type t2, such that t2 is at least twice
1169   the size of t1. The type of the entire expression is also t2.
1170   WIDEN_SUM_EXPR is equivalent to first widening (promoting)
1171   the first argument from type t1 to type t2, and then summing it
1172   with the second argument.  */
1173DEFTREECODE (WIDEN_SUM_EXPR, "widen_sum_expr", tcc_binary, 2)
1174
1175/* Widening multiplication.
1176   The two arguments are of type t1.
1177   The result is of type t2, such that t2 is at least twice
1178   the size of t1. WIDEN_MULT_EXPR is equivalent to first widening (promoting)
1179   the arguments from type t1 to type t2, and then multiplying them.  */
1180DEFTREECODE (WIDEN_MULT_EXPR, "widen_mult_expr", tcc_binary, 2)
1181
1182/* Widening multiply-accumulate.
1183   The first two arguments are of type t1.
1184   The third argument and the result are of type t2, such as t2 is at least
1185   twice the size of t1.  t1 and t2 must be integral or fixed-point types.
1186   The expression is equivalent to a WIDEN_MULT_EXPR operation
1187   of the first two operands followed by an add or subtract of the third
1188   operand.  */
1189DEFTREECODE (WIDEN_MULT_PLUS_EXPR, "widen_mult_plus_expr", tcc_expression, 3)
1190/* This is like the above, except in the final expression the multiply result
1191   is subtracted from t3.  */
1192DEFTREECODE (WIDEN_MULT_MINUS_EXPR, "widen_mult_minus_expr", tcc_expression, 3)
1193
1194/* Widening shift left.
1195   The first operand is of type t1.
1196   The second operand is the number of bits to shift by; it need not be the
1197   same type as the first operand and result.
1198   Note that the result is undefined if the second operand is larger
1199   than or equal to the first operand's type size.
1200   The type of the entire expression is t2, such that t2 is at least twice
1201   the size of t1.
1202   WIDEN_LSHIFT_EXPR is equivalent to first widening (promoting)
1203   the first argument from type t1 to type t2, and then shifting it
1204   by the second argument.  */
1205DEFTREECODE (WIDEN_LSHIFT_EXPR, "widen_lshift_expr", tcc_binary, 2)
1206
1207/* Fused multiply-add.
1208   All operands and the result are of the same type.  No intermediate
1209   rounding is performed after multiplying operand one with operand two
1210   before adding operand three.  */
1211DEFTREECODE (FMA_EXPR, "fma_expr", tcc_expression, 3)
1212
1213/* Whole vector left/right shift in bits.
1214   Operand 0 is a vector to be shifted.
1215   Operand 1 is an integer shift amount in bits.  */
1216DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2)
1217DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2)
1218
1219/* Widening vector multiplication.
1220   The two operands are vectors with N elements of size S. Multiplying the
1221   elements of the two vectors will result in N products of size 2*S.
1222   VEC_WIDEN_MULT_HI_EXPR computes the N/2 high products.
1223   VEC_WIDEN_MULT_LO_EXPR computes the N/2 low products.  */
1224DEFTREECODE (VEC_WIDEN_MULT_HI_EXPR, "widen_mult_hi_expr", tcc_binary, 2)
1225DEFTREECODE (VEC_WIDEN_MULT_LO_EXPR, "widen_mult_lo_expr", tcc_binary, 2)
1226
1227/* Similarly, but return the even or odd N/2 products.  */
1228DEFTREECODE (VEC_WIDEN_MULT_EVEN_EXPR, "widen_mult_even_expr", tcc_binary, 2)
1229DEFTREECODE (VEC_WIDEN_MULT_ODD_EXPR, "widen_mult_odd_expr", tcc_binary, 2)
1230
1231/* Unpack (extract and promote/widen) the high/low elements of the input
1232   vector into the output vector.  The input vector has twice as many
1233   elements as the output vector, that are half the size of the elements
1234   of the output vector.  This is used to support type promotion. */
1235DEFTREECODE (VEC_UNPACK_HI_EXPR, "vec_unpack_hi_expr", tcc_unary, 1)
1236DEFTREECODE (VEC_UNPACK_LO_EXPR, "vec_unpack_lo_expr", tcc_unary, 1)
1237
1238/* Unpack (extract) the high/low elements of the input vector, convert
1239   fixed point values to floating point and widen elements into the
1240   output vector.  The input vector has twice as many elements as the output
1241   vector, that are half the size of the elements of the output vector.  */
1242DEFTREECODE (VEC_UNPACK_FLOAT_HI_EXPR, "vec_unpack_float_hi_expr", tcc_unary, 1)
1243DEFTREECODE (VEC_UNPACK_FLOAT_LO_EXPR, "vec_unpack_float_lo_expr", tcc_unary, 1)
1244
1245/* Pack (demote/narrow and merge) the elements of the two input vectors
1246   into the output vector using truncation/saturation.
1247   The elements of the input vectors are twice the size of the elements of the
1248   output vector.  This is used to support type demotion.  */
1249DEFTREECODE (VEC_PACK_TRUNC_EXPR, "vec_pack_trunc_expr", tcc_binary, 2)
1250DEFTREECODE (VEC_PACK_SAT_EXPR, "vec_pack_sat_expr", tcc_binary, 2)
1251
1252/* Convert floating point values of the two input vectors to integer
1253   and pack (narrow and merge) the elements into the output vector. The
1254   elements of the input vector are twice the size of the elements of
1255   the output vector.  */
1256DEFTREECODE (VEC_PACK_FIX_TRUNC_EXPR, "vec_pack_fix_trunc_expr", tcc_binary, 2)
1257
1258/* Widening vector shift left in bits.
1259   Operand 0 is a vector to be shifted with N elements of size S.
1260   Operand 1 is an integer shift amount in bits.
1261   The result of the operation is N elements of size 2*S.
1262   VEC_WIDEN_LSHIFT_HI_EXPR computes the N/2 high results.
1263   VEC_WIDEN_LSHIFT_LO_EXPR computes the N/2 low results.
1264 */
1265DEFTREECODE (VEC_WIDEN_LSHIFT_HI_EXPR, "widen_lshift_hi_expr", tcc_binary, 2)
1266DEFTREECODE (VEC_WIDEN_LSHIFT_LO_EXPR, "widen_lshift_lo_expr", tcc_binary, 2)
1267
1268/* PREDICT_EXPR.  Specify hint for branch prediction.  The
1269   PREDICT_EXPR_PREDICTOR specify predictor and PREDICT_EXPR_OUTCOME the
1270   outcome (0 for not taken and 1 for taken).  Once the profile is guessed
1271   all conditional branches leading to execution paths executing the
1272   PREDICT_EXPR will get predicted by the specified predictor.  */
1273DEFTREECODE (PREDICT_EXPR, "predict_expr", tcc_expression, 1)
1274
1275/* OPTIMIZATION_NODE.  Node to store the optimization options.  */
1276DEFTREECODE (OPTIMIZATION_NODE, "optimization_node", tcc_exceptional, 0)
1277
1278/* TARGET_OPTION_NODE.  Node to store the target specific options.  */
1279DEFTREECODE (TARGET_OPTION_NODE, "target_option_node", tcc_exceptional, 0)
1280
1281/* ANNOTATE_EXPR.
1282   Operand 0 is the expression to be annotated.
1283   Operand 1 is the annotation id. */
1284DEFTREECODE (ANNOTATE_EXPR, "annotate_expr", tcc_expression, 2)
1285
1286/* Cilk spawn statement
1287   Operand 0 is the CALL_EXPR.  */
1288DEFTREECODE (CILK_SPAWN_STMT, "cilk_spawn_stmt", tcc_statement, 1)
1289
1290/* Cilk Sync statement: Does not have any operands.  */
1291DEFTREECODE (CILK_SYNC_STMT, "cilk_sync_stmt", tcc_statement, 0)
1292
1293/*
1294Local variables:
1295mode:c
1296End:
1297*/
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