1/* This file contains the definitions and documentation for the 2 tree codes used in GCC. 3 Copyright (C) 1987, 1988, 1993, 1995, 1997, 1998, 2000, 2001, 2004, 2005, 4 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 3, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING3. If not see 20<http://www.gnu.org/licenses/>. */ 21 22 23/* For tcc_references, tcc_expression, tcc_comparison, tcc_unary, 24 tcc_binary, and tcc_statement nodes, which use struct tree_exp, the 25 4th element is the number of argument slots to allocate. This 26 determines the size of the tree node object. Other nodes use 27 different structures, and the size is determined by the tree_union 28 member structure; the 4th element should be zero. Languages that 29 define language-specific tcc_exceptional or tcc_constant codes must 30 define the tree_size langhook to say how big they are. 31 32 These tree codes have been sorted so that the macros in tree.h that 33 check for various tree codes are optimized into range checks. This 34 gives a measurable performance improvement. When adding a new 35 code, consider its placement in relation to the other codes. */ 36 37/* Any erroneous construct is parsed into a node of this type. 38 This type of node is accepted without complaint in all contexts 39 by later parsing activities, to avoid multiple error messages 40 for one error. 41 No fields in these nodes are used except the TREE_CODE. */ 42DEFTREECODE (ERROR_MARK, "error_mark", tcc_exceptional, 0) 43 44/* Used to represent a name (such as, in the DECL_NAME of a decl node). 45 Internally it looks like a STRING_CST node. 46 There is only one IDENTIFIER_NODE ever made for any particular name. 47 Use `get_identifier' to get it (or create it, the first time). */ 48DEFTREECODE (IDENTIFIER_NODE, "identifier_node", tcc_exceptional, 0) 49 50/* Has the TREE_VALUE and TREE_PURPOSE fields. */ 51/* These nodes are made into lists by chaining through the 52 TREE_CHAIN field. The elements of the list live in the 53 TREE_VALUE fields, while TREE_PURPOSE fields are occasionally 54 used as well to get the effect of Lisp association lists. */ 55DEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0) 56 57/* These nodes contain an array of tree nodes. */ 58DEFTREECODE (TREE_VEC, "tree_vec", tcc_exceptional, 0) 59 60/* A symbol binding block. These are arranged in a tree, 61 where the BLOCK_SUBBLOCKS field contains a chain of subblocks 62 chained through the BLOCK_CHAIN field. 63 BLOCK_SUPERCONTEXT points to the parent block. 64 For a block which represents the outermost scope of a function, it 65 points to the FUNCTION_DECL node. 66 BLOCK_VARS points to a chain of decl nodes. 67 BLOCK_CHAIN points to the next BLOCK at the same level. 68 BLOCK_ABSTRACT_ORIGIN points to the original (abstract) tree node which 69 this block is an instance of, or else is NULL to indicate that this 70 block is not an instance of anything else. When non-NULL, the value 71 could either point to another BLOCK node or it could point to a 72 FUNCTION_DECL node (e.g. in the case of a block representing the 73 outermost scope of a particular inlining of a function). 74 BLOCK_ABSTRACT is nonzero if the block represents an abstract 75 instance of a block (i.e. one which is nested within an abstract 76 instance of an inline function). 77 TREE_ASM_WRITTEN is nonzero if the block was actually referenced 78 in the generated assembly. */ 79DEFTREECODE (BLOCK, "block", tcc_exceptional, 0) 80 81/* Each data type is represented by a tree node whose code is one of 82 the following: */ 83/* Each node that represents a data type has a component TYPE_SIZE 84 containing a tree that is an expression for the size in bits. 85 The TYPE_MODE contains the machine mode for values of this type. 86 The TYPE_POINTER_TO field contains a type for a pointer to this type, 87 or zero if no such has been created yet. 88 The TYPE_NEXT_VARIANT field is used to chain together types 89 that are variants made by type modifiers such as "const" and "volatile". 90 The TYPE_MAIN_VARIANT field, in any member of such a chain, 91 points to the start of the chain. 92 The TYPE_NAME field contains info on the name used in the program 93 for this type (for GDB symbol table output). It is either a 94 TYPE_DECL node, for types that are typedefs, or an IDENTIFIER_NODE 95 in the case of structs, unions or enums that are known with a tag, 96 or zero for types that have no special name. 97 The TYPE_CONTEXT for any sort of type which could have a name or 98 which could have named members (e.g. tagged types in C/C++) will 99 point to the node which represents the scope of the given type, or 100 will be NULL_TREE if the type has "file scope". For most types, this 101 will point to a BLOCK node or a FUNCTION_DECL node, but it could also 102 point to a FUNCTION_TYPE node (for types whose scope is limited to the 103 formal parameter list of some function type specification) or it 104 could point to a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE node 105 (for C++ "member" types). 106 For non-tagged-types, TYPE_CONTEXT need not be set to anything in 107 particular, since any type which is of some type category (e.g. 108 an array type or a function type) which cannot either have a name 109 itself or have named members doesn't really have a "scope" per se. 110 The TREE_CHAIN field is used as a forward-references to names for 111 ENUMERAL_TYPE, RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE nodes; 112 see below. */ 113 114/* The ordering of the following codes is optimized for the checking 115 macros in tree.h. Changing the order will degrade the speed of the 116 compiler. OFFSET_TYPE, ENUMERAL_TYPE, BOOLEAN_TYPE, INTEGER_TYPE, 117 REAL_TYPE, POINTER_TYPE. */ 118 119/* An offset is a pointer relative to an object. 120 The TREE_TYPE field is the type of the object at the offset. 121 The TYPE_OFFSET_BASETYPE points to the node for the type of object 122 that the offset is relative to. */ 123DEFTREECODE (OFFSET_TYPE, "offset_type", tcc_type, 0) 124 125/* C enums. The type node looks just like an INTEGER_TYPE node. 126 The symbols for the values of the enum type are defined by 127 CONST_DECL nodes, but the type does not point to them; 128 however, the TYPE_VALUES is a list in which each element's TREE_PURPOSE 129 is a name and the TREE_VALUE is the value (an INTEGER_CST node). */ 130/* A forward reference `enum foo' when no enum named foo is defined yet 131 has zero (a null pointer) in its TYPE_SIZE. The tag name is in 132 the TYPE_NAME field. If the type is later defined, the normal 133 fields are filled in. 134 RECORD_TYPE, UNION_TYPE, and QUAL_UNION_TYPE forward refs are 135 treated similarly. */ 136DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0) 137 138/* Boolean type (true or false are the only values). Looks like an 139 INTEGRAL_TYPE. */ 140DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0) 141 142/* Integer types in all languages, including char in C. 143 Also used for sub-ranges of other discrete types. 144 Has components TYPE_MIN_VALUE, TYPE_MAX_VALUE (expressions, inclusive) 145 and TYPE_PRECISION (number of bits used by this type). 146 In the case of a subrange type in Pascal, the TREE_TYPE 147 of this will point at the supertype (another INTEGER_TYPE, 148 or an ENUMERAL_TYPE or BOOLEAN_TYPE). 149 Otherwise, the TREE_TYPE is zero. */ 150DEFTREECODE (INTEGER_TYPE, "integer_type", tcc_type, 0) 151 152/* C's float and double. Different floating types are distinguished 153 by machine mode and by the TYPE_SIZE and the TYPE_PRECISION. */ 154DEFTREECODE (REAL_TYPE, "real_type", tcc_type, 0) 155 156/* The ordering of the following codes is optimized for the checking 157 macros in tree.h. Changing the order will degrade the speed of the 158 compiler. POINTER_TYPE, REFERENCE_TYPE. Note that this range 159 overlaps the previous range of ordered types. */ 160 161/* All pointer-to-x types have code POINTER_TYPE. 162 The TREE_TYPE points to the node for the type pointed to. */ 163DEFTREECODE (POINTER_TYPE, "pointer_type", tcc_type, 0) 164 165/* A reference is like a pointer except that it is coerced 166 automatically to the value it points to. Used in C++. */ 167DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0) 168 169/* The C++ decltype(nullptr) type. */ 170DEFTREECODE (NULLPTR_TYPE, "nullptr_type", tcc_type, 0) 171 172/* _Fract and _Accum types in Embedded-C. Different fixed-point types 173 are distinguished by machine mode and by the TYPE_SIZE and the 174 TYPE_PRECISION. */ 175DEFTREECODE (FIXED_POINT_TYPE, "fixed_point_type", tcc_type, 0) 176 177/* The ordering of the following codes is optimized for the checking 178 macros in tree.h. Changing the order will degrade the speed of the 179 compiler. COMPLEX_TYPE, VECTOR_TYPE, ARRAY_TYPE. */ 180 181/* Complex number types. The TREE_TYPE field is the data type 182 of the real and imaginary parts. It must be of scalar 183 arithmetic type, not including pointer type. */ 184DEFTREECODE (COMPLEX_TYPE, "complex_type", tcc_type, 0) 185 186/* Vector types. The TREE_TYPE field is the data type of the vector 187 elements. The TYPE_PRECISION field is the number of subparts of 188 the vector. */ 189DEFTREECODE (VECTOR_TYPE, "vector_type", tcc_type, 0) 190 191/* The ordering of the following codes is optimized for the checking 192 macros in tree.h. Changing the order will degrade the speed of the 193 compiler. ARRAY_TYPE, RECORD_TYPE, UNION_TYPE, QUAL_UNION_TYPE. 194 Note that this range overlaps the previous range. */ 195 196/* Types of arrays. Special fields: 197 TREE_TYPE Type of an array element. 198 TYPE_DOMAIN Type to index by. 199 Its range of values specifies the array length. 200 The field TYPE_POINTER_TO (TREE_TYPE (array_type)) is always nonzero 201 and holds the type to coerce a value of that array type to in C. 202 TYPE_STRING_FLAG indicates a string (in contrast to an array of chars) 203 in languages (such as Chill) that make a distinction. */ 204/* Array types in C or Pascal */ 205DEFTREECODE (ARRAY_TYPE, "array_type", tcc_type, 0) 206 207/* Struct in C, or record in Pascal. */ 208/* Special fields: 209 TYPE_FIELDS chain of FIELD_DECLs for the fields of the struct, 210 and VAR_DECLs, TYPE_DECLs and CONST_DECLs for record-scope variables, 211 types and enumerators. 212 A few may need to be added for Pascal. */ 213/* See the comment above, before ENUMERAL_TYPE, for how 214 forward references to struct tags are handled in C. */ 215DEFTREECODE (RECORD_TYPE, "record_type", tcc_type, 0) 216 217/* Union in C. Like a struct, except that the offsets of the fields 218 will all be zero. */ 219/* See the comment above, before ENUMERAL_TYPE, for how 220 forward references to union tags are handled in C. */ 221DEFTREECODE (UNION_TYPE, "union_type", tcc_type, 0) /* C union type */ 222 223/* Similar to UNION_TYPE, except that the expressions in DECL_QUALIFIER 224 in each FIELD_DECL determine what the union contains. The first 225 field whose DECL_QUALIFIER expression is true is deemed to occupy 226 the union. */ 227DEFTREECODE (QUAL_UNION_TYPE, "qual_union_type", tcc_type, 0) 228 229/* The ordering of the following codes is optimized for the checking 230 macros in tree.h. Changing the order will degrade the speed of the 231 compiler. VOID_TYPE, FUNCTION_TYPE, METHOD_TYPE. */ 232 233/* The void type in C */ 234DEFTREECODE (VOID_TYPE, "void_type", tcc_type, 0) 235 236/* Type of functions. Special fields: 237 TREE_TYPE type of value returned. 238 TYPE_ARG_TYPES list of types of arguments expected. 239 this list is made of TREE_LIST nodes. 240 Types of "Procedures" in languages where they are different from functions 241 have code FUNCTION_TYPE also, but then TREE_TYPE is zero or void type. */ 242DEFTREECODE (FUNCTION_TYPE, "function_type", tcc_type, 0) 243 244/* METHOD_TYPE is the type of a function which takes an extra first 245 argument for "self", which is not present in the declared argument list. 246 The TREE_TYPE is the return type of the method. The TYPE_METHOD_BASETYPE 247 is the type of "self". TYPE_ARG_TYPES is the real argument list, which 248 includes the hidden argument for "self". */ 249DEFTREECODE (METHOD_TYPE, "method_type", tcc_type, 0) 250 251/* This is a language-specific kind of type. 252 Its meaning is defined by the language front end. 253 layout_type does not know how to lay this out, 254 so the front-end must do so manually. */ 255DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0) 256 257/* Expressions */ 258 259/* First, the constants. */ 260 261/* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, 262 32 bits each, giving us a 64 bit constant capability. INTEGER_CST 263 nodes can be shared, and therefore should be considered read only. 264 They should be copied, before setting a flag such as TREE_OVERFLOW. 265 If an INTEGER_CST has TREE_OVERFLOW already set, it is known to be unique. 266 INTEGER_CST nodes are created for the integral types, for pointer 267 types and for vector and float types in some circumstances. */ 268DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0) 269 270/* Contents are in TREE_REAL_CST field. */ 271DEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0) 272 273/* Contents are in TREE_FIXED_CST field. */ 274DEFTREECODE (FIXED_CST, "fixed_cst", tcc_constant, 0) 275 276/* Contents are in TREE_REALPART and TREE_IMAGPART fields, 277 whose contents are other constant nodes. */ 278DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0) 279 280/* Contents are in TREE_VECTOR_CST_ELTS field. */ 281DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0) 282 283/* Contents are TREE_STRING_LENGTH and the actual contents of the string. */ 284DEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0) 285 286/* Declarations. All references to names are represented as ..._DECL 287 nodes. The decls in one binding context are chained through the 288 TREE_CHAIN field. Each DECL has a DECL_NAME field which contains 289 an IDENTIFIER_NODE. (Some decls, most often labels, may have zero 290 as the DECL_NAME). DECL_CONTEXT points to the node representing 291 the context in which this declaration has its scope. For 292 FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or 293 QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL, 294 PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this 295 points to either the FUNCTION_DECL for the containing function, the 296 RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or 297 a TRANSLATION_UNIT_DECL if the given decl has "file scope". 298 DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract) 299 ..._DECL node of which this decl is an (inlined or template expanded) 300 instance. 301 The TREE_TYPE field holds the data type of the object, when relevant. 302 LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field 303 contents are the type whose name is being declared. 304 The DECL_ALIGN, DECL_SIZE, 305 and DECL_MODE fields exist in decl nodes just as in type nodes. 306 They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes. 307 308 DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for 309 the location. DECL_VOFFSET holds an expression for a variable 310 offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer). 311 These fields are relevant only in FIELD_DECLs and PARM_DECLs. 312 313 DECL_INITIAL holds the value to initialize a variable to, 314 or the value of a constant. For a function, it holds the body 315 (a node of type BLOCK representing the function's binding contour 316 and whose body contains the function's statements.) For a LABEL_DECL 317 in C, it is a flag, nonzero if the label's definition has been seen. 318 319 PARM_DECLs use a special field: 320 DECL_ARG_TYPE is the type in which the argument is actually 321 passed, which may be different from its type within the function. 322 323 FUNCTION_DECLs use four special fields: 324 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments. 325 DECL_RESULT holds a RESULT_DECL node for the value of a function. 326 The DECL_RTL field is 0 for a function that returns no value. 327 (C functions returning void have zero here.) 328 The TREE_TYPE field is the type in which the result is actually 329 returned. This is usually the same as the return type of the 330 FUNCTION_DECL, but it may be a wider integer type because of 331 promotion. 332 DECL_FUNCTION_CODE is a code number that is nonzero for 333 built-in functions. Its value is an enum built_in_function 334 that says which built-in function it is. 335 336 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE 337 holds a line number. In some cases these can be the location of 338 a reference, if no definition has been seen. 339 340 DECL_ABSTRACT is nonzero if the decl represents an abstract instance 341 of a decl (i.e. one which is nested within an abstract instance of a 342 inline function. */ 343 344DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0) 345DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0) 346/* The ordering of the following codes is optimized for the checking 347 macros in tree.h. Changing the order will degrade the speed of the 348 compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL, 349 TYPE_DECL. */ 350DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0) 351DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0) 352DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0) 353DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0) 354DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0) 355DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0) 356 357/* A "declaration" of a debug temporary. It should only appear in 358 DEBUG stmts. */ 359DEFTREECODE (DEBUG_EXPR_DECL, "debug_expr_decl", tcc_declaration, 0) 360 361/* A namespace declaration. Namespaces appear in DECL_CONTEXT of other 362 _DECLs, providing a hierarchy of names. */ 363DEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0) 364 365/* A declaration import. 366 The C++ FE uses this to represent a using-directive; eg: 367 "using namespace foo". 368 But it could be used to represent any declaration import construct. 369 Whenever a declaration import appears in a lexical block, the BLOCK node 370 representing that lexical block in GIMPLE will contain an IMPORTED_DECL 371 node, linked via BLOCK_VARS accessor of the said BLOCK. 372 For a given NODE which code is IMPORTED_DECL, 373 IMPORTED_DECL_ASSOCIATED_DECL (NODE) accesses the imported declaration. */ 374DEFTREECODE (IMPORTED_DECL, "imported_decl", tcc_declaration, 0) 375 376/* A translation unit. This is not technically a declaration, since it 377 can't be looked up, but it's close enough. */ 378DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\ 379 tcc_declaration, 0) 380 381/* References to storage. */ 382 383/* The ordering of the following codes is optimized for the classification 384 in handled_component_p. Keep them in a consecutive group. */ 385 386/* Value is structure or union component. 387 Operand 0 is the structure or union (an expression). 388 Operand 1 is the field (a node of type FIELD_DECL). 389 Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured 390 in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT. */ 391DEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3) 392 393/* Reference to a group of bits within an object. Similar to COMPONENT_REF 394 except the position is given explicitly rather than via a FIELD_DECL. 395 Operand 0 is the structure or union expression; 396 operand 1 is a tree giving the constant number of bits being referenced; 397 operand 2 is a tree giving the constant position of the first referenced bit. 398 The result type width has to match the number of bits referenced. 399 If the result type is integral, its signedness specifies how it is extended 400 to its mode width. */ 401DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3) 402 403/* Used only on an operand of complex type, these return 404 a value of the corresponding component type. */ 405DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1) 406DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1) 407 408/* Array indexing. 409 Operand 0 is the array; operand 1 is a (single) array index. 410 Operand 2, if present, is a copy of TYPE_MIN_VALUE of the index. 411 Operand 3, if present, is the element size, measured in units of 412 the alignment of the element type. */ 413DEFTREECODE (ARRAY_REF, "array_ref", tcc_reference, 4) 414 415/* Likewise, except that the result is a range ("slice") of the array. The 416 starting index of the resulting array is taken from operand 1 and the size 417 of the range is taken from the type of the expression. */ 418DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4) 419 420/* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */ 421DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1) 422 423/* Used to represent lookup in a virtual method table which is dependent on 424 the runtime type of an object. Operands are: 425 OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use. 426 OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is 427 being performed. Through this the optimizers may be able to statically 428 determine the dynamic type of the object. 429 OBJ_TYPE_REF_TOKEN: An integer index to the virtual method table. */ 430DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3) 431 432/* Constructor: return an aggregate value made from specified components. 433 In C, this is used only for structure and array initializers. 434 The operand is a sequence of component values made out of a VEC of 435 struct constructor_elt. 436 437 For ARRAY_TYPE: 438 The field INDEX of each constructor_elt is the corresponding index. 439 If the index is a RANGE_EXPR, it is a short-hand for many nodes, 440 one for each index in the range. (If the corresponding field VALUE 441 has side-effects, they are evaluated once for each element. Wrap the 442 value in a SAVE_EXPR if you want to evaluate side effects only once.) 443 444 For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: 445 The field INDEX of each node is a FIELD_DECL. */ 446DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0) 447 448/* The expression types are mostly straightforward, with the fourth argument 449 of DEFTREECODE saying how many operands there are. 450 Unless otherwise specified, the operands are expressions and the 451 types of all the operands and the expression must all be the same. */ 452 453/* Contains two expressions to compute, one followed by the other. 454 the first value is ignored. The second one's value is used. The 455 type of the first expression need not agree with the other types. */ 456DEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2) 457 458/* Assignment expression. Operand 0 is the what to set; 1, the new value. */ 459DEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2) 460 461/* Initialization expression. Operand 0 is the variable to initialize; 462 Operand 1 is the initializer. This differs from MODIFY_EXPR in that any 463 reference to the referent of operand 0 within operand 1 is undefined. */ 464DEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2) 465 466/* For TARGET_EXPR, operand 0 is the target of an initialization, 467 operand 1 is the initializer for the target, which may be void 468 if simply expanding it initializes the target. 469 operand 2 is the cleanup for this node, if any. 470 operand 3 is the saved initializer after this node has been 471 expanded once; this is so we can re-expand the tree later. */ 472DEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4) 473 474/* Conditional expression ( ... ? ... : ... in C). 475 Operand 0 is the condition. 476 Operand 1 is the then-value. 477 Operand 2 is the else-value. 478 Operand 0 may be of any type. 479 Operand 1 must have the same type as the entire expression, unless 480 it unconditionally throws an exception, in which case it should 481 have VOID_TYPE. The same constraints apply to operand 2. The 482 condition in operand 0 must be of integral type. 483 484 In cfg gimple, if you do not have a selection expression, operands 485 1 and 2 are NULL. The operands are then taken from the cfg edges. */ 486DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3) 487 488/* Vector conditional expression. It is like COND_EXPR, but with 489 vector operands. 490 491 A = VEC_COND_EXPR ( X < Y, B, C) 492 493 means 494 495 for (i=0; i<N; i++) 496 A[i] = X[i] < Y[i] ? B[i] : C[i]; 497*/ 498DEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3) 499 500/* Vector permutation expression. A = VEC_PERM_EXPR<v0, v1, mask> means 501 502 N = length(mask) 503 foreach i in N: 504 M = mask[i] % (2*N) 505 A = M < N ? v0[M] : v1[M-N] 506 507 V0 and V1 are vectors of the same type. MASK is an integer-typed 508 vector. The number of MASK elements must be the same with the 509 number of elements in V0 and V1. The size of the inner type 510 of the MASK and of the V0 and V1 must be the same. 511*/ 512DEFTREECODE (VEC_PERM_EXPR, "vec_perm_expr", tcc_expression, 3) 513 514/* Declare local variables, including making RTL and allocating space. 515 BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables. 516 BIND_EXPR_BODY is the body, the expression to be computed using 517 the variables. The value of operand 1 becomes that of the BIND_EXPR. 518 BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings 519 for debugging purposes. If this BIND_EXPR is actually expanded, 520 that sets the TREE_USED flag in the BLOCK. 521 522 The BIND_EXPR is not responsible for informing parsers 523 about these variables. If the body is coming from the input file, 524 then the code that creates the BIND_EXPR is also responsible for 525 informing the parser of the variables. 526 527 If the BIND_EXPR is ever expanded, its TREE_USED flag is set. 528 This tells the code for debugging symbol tables not to ignore the BIND_EXPR. 529 If the BIND_EXPR should be output for debugging but will not be expanded, 530 set the TREE_USED flag by hand. 531 532 In order for the BIND_EXPR to be known at all, the code that creates it 533 must also install it as a subblock in the tree of BLOCK 534 nodes for the function. */ 535DEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3) 536 537/* Function call. CALL_EXPRs are represented by variably-sized expression 538 nodes. There are at least three fixed operands. Operand 0 is an 539 INTEGER_CST node containing the total operand count, the number of 540 arguments plus 3. Operand 1 is the function, while operand 2 is 541 is static chain argument, or NULL. The remaining operands are the 542 arguments to the call. */ 543DEFTREECODE (CALL_EXPR, "call_expr", tcc_vl_exp, 3) 544 545/* Specify a value to compute along with its corresponding cleanup. 546 Operand 0 is the cleanup expression. 547 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, 548 which must exist. This differs from TRY_CATCH_EXPR in that operand 1 549 is always evaluated when cleanups are run. */ 550DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1) 551 552/* Specify a cleanup point. 553 Operand 0 is an expression that may have cleanups. If it does, those 554 cleanups are executed after the expression is expanded. 555 556 Note that if the expression is a reference to storage, it is forced out 557 of memory before the cleanups are run. This is necessary to handle 558 cases where the cleanups modify the storage referenced; in the 559 expression 't.i', if 't' is a struct with an integer member 'i' and a 560 cleanup which modifies 'i', the value of the expression depends on 561 whether the cleanup is run before or after 't.i' is evaluated. When 562 expand_expr is run on 't.i', it returns a MEM. This is not good enough; 563 the value of 't.i' must be forced out of memory. 564 565 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have 566 BLKmode, because it will not be forced out of memory. */ 567DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1) 568 569/* The following code is used in languages that have types where some 570 field in an object of the type contains a value that is used in the 571 computation of another field's offset or size and/or the size of the 572 type. The positions and/or sizes of fields can vary from object to 573 object of the same type or even for one and the same object within 574 its scope. 575 576 Record types with discriminants in Ada or schema types in Pascal are 577 examples of such types. This mechanism is also used to create "fat 578 pointers" for unconstrained array types in Ada; the fat pointer is a 579 structure one of whose fields is a pointer to the actual array type 580 and the other field is a pointer to a template, which is a structure 581 containing the bounds of the array. The bounds in the type pointed 582 to by the first field in the fat pointer refer to the values in the 583 template. 584 585 When you wish to construct such a type you need "self-references" 586 that allow you to reference the object having this type from the 587 TYPE node, i.e. without having a variable instantiating this type. 588 589 Such a "self-references" is done using a PLACEHOLDER_EXPR. This is 590 a node that will later be replaced with the object being referenced. 591 Its type is that of the object and selects which object to use from 592 a chain of references (see below). No other slots are used in the 593 PLACEHOLDER_EXPR. 594 595 For example, if your type FOO is a RECORD_TYPE with a field BAR, 596 and you need the value of <variable>.BAR to calculate TYPE_SIZE 597 (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR 598 whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with 599 the PLACEHOLDER_EXPR as the first operand (which has the correct 600 type). Later, when the size is needed in the program, the back-end 601 will find this PLACEHOLDER_EXPR and generate code to calculate the 602 actual size at run-time. In the following, we describe how this 603 calculation is done. 604 605 When we wish to evaluate a size or offset, we check whether it contains a 606 PLACEHOLDER_EXPR. If it does, we call substitute_placeholder_in_expr 607 passing both that tree and an expression within which the object may be 608 found. The latter expression is the object itself in the simple case of 609 an Ada record with discriminant, but it can be the array in the case of an 610 unconstrained array. 611 612 In the latter case, we need the fat pointer, because the bounds of 613 the array can only be accessed from it. However, we rely here on the 614 fact that the expression for the array contains the dereference of 615 the fat pointer that obtained the array pointer. */ 616 617/* Denotes a record to later be substituted before evaluating this expression. 618 The type of this expression is used to find the record to replace it. */ 619DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0) 620 621/* Simple arithmetic. */ 622DEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2) 623DEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2) 624DEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2) 625 626/* Pointer addition. The first operand is always a pointer and the 627 second operand is an integer of type sizetype. */ 628DEFTREECODE (POINTER_PLUS_EXPR, "pointer_plus_expr", tcc_binary, 2) 629 630/* Division for integer result that rounds the quotient toward zero. */ 631DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2) 632 633/* Division for integer result that rounds the quotient toward infinity. */ 634DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2) 635 636/* Division for integer result that rounds toward minus infinity. */ 637DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2) 638 639/* Division for integer result that rounds toward nearest integer. */ 640DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2) 641 642/* Four kinds of remainder that go with the four kinds of division. */ 643DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2) 644DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2) 645DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2) 646DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2) 647 648/* Division for real result. */ 649DEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2) 650 651/* Division which is not supposed to need rounding. 652 Used for pointer subtraction in C. */ 653DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2) 654 655/* Conversion of real to fixed point by truncation. */ 656DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1) 657 658/* Conversion of an integer to a real. */ 659DEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1) 660 661/* Unary negation. */ 662DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1) 663 664/* Minimum and maximum values. When used with floating point, if both 665 operands are zeros, or if either operand is NaN, then it is unspecified 666 which of the two operands is returned as the result. */ 667DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2) 668DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2) 669 670/* Represents the absolute value of the operand. 671 672 An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The 673 operand of the ABS_EXPR must have the same type. */ 674DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1) 675 676/* Shift operations for shift and rotate. 677 Shift means logical shift if done on an 678 unsigned type, arithmetic shift if done on a signed type. 679 The second operand is the number of bits to 680 shift by; it need not be the same type as the first operand and result. 681 Note that the result is undefined if the second operand is larger 682 than or equal to the first operand's type size. 683 684 The first operand of a shift can have either an integer or a 685 (non-integer) fixed-point type. We follow the ISO/IEC TR 18037:2004 686 semantics for the latter. 687 688 Rotates are defined for integer types only. */ 689DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2) 690DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2) 691DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2) 692DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2) 693 694/* Bitwise operations. Operands have same mode as result. */ 695DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2) 696DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2) 697DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2) 698DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1) 699 700/* ANDIF and ORIF allow the second operand not to be computed if the 701 value of the expression is determined from the first operand. AND, 702 OR, and XOR always compute the second operand whether its value is 703 needed or not (for side effects). The operand may have 704 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be 705 either zero or one. For example, a TRUTH_NOT_EXPR will never have 706 an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be 707 used to compare the VAR_DECL to zero, thereby obtaining a node with 708 value zero or one. */ 709DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2) 710DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2) 711DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2) 712DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2) 713DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2) 714DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1) 715 716/* Relational operators. 717 `EQ_EXPR' and `NE_EXPR' are allowed for any types. 718 The others are allowed only for integer (or pointer or enumeral) 719 or real types. 720 In all cases the operands will have the same type, 721 and the value is either the type used by the language for booleans 722 or an integer vector type of the same size and with the same number 723 of elements as the comparison operands. True for a vector of 724 comparison results has all bits set while false is equal to zero. */ 725DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2) 726DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2) 727DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2) 728DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2) 729DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2) 730DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2) 731 732/* Additional relational operators for floating point unordered. */ 733DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2) 734DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2) 735 736/* These are equivalent to unordered or ... */ 737DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2) 738DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2) 739DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2) 740DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2) 741DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2) 742 743/* This is the reverse of uneq_expr. */ 744DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2) 745 746DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2) 747 748/* Represents a re-association barrier for floating point expressions 749 like explicit parenthesis in fortran. */ 750DEFTREECODE (PAREN_EXPR, "paren_expr", tcc_unary, 1) 751 752/* Represents a conversion of type of a value. 753 All conversions, including implicit ones, must be 754 represented by CONVERT_EXPR or NOP_EXPR nodes. */ 755DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1) 756 757/* Conversion of a pointer value to a pointer to a different 758 address space. */ 759DEFTREECODE (ADDR_SPACE_CONVERT_EXPR, "addr_space_convert_expr", tcc_unary, 1) 760 761/* Conversion of a fixed-point value to an integer, a real, or a fixed-point 762 value. Or conversion of a fixed-point value from an integer, a real, or 763 a fixed-point value. */ 764DEFTREECODE (FIXED_CONVERT_EXPR, "fixed_convert_expr", tcc_unary, 1) 765 766/* Represents a conversion expected to require no code to be generated. */ 767DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1) 768 769/* Value is same as argument, but guaranteed not an lvalue. */ 770DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1) 771 772/* Represents viewing something of one type as being of a second type. 773 This corresponds to an "Unchecked Conversion" in Ada and roughly to 774 the idiom *(type2 *)&X in C. The only operand is the value to be 775 viewed as being of another type. It is undefined if the type of the 776 input and of the expression have different sizes. 777 778 This code may also be used within the LHS of a MODIFY_EXPR, in which 779 case no actual data motion may occur. TREE_ADDRESSABLE will be set in 780 this case and GCC must abort if it could not do the operation without 781 generating insns. */ 782DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1) 783 784/* A COMPOUND_LITERAL_EXPR represents a literal that is placed in a DECL. The 785 COMPOUND_LITERAL_EXPR_DECL_EXPR is the a DECL_EXPR containing the decl 786 for the anonymous object represented by the COMPOUND_LITERAL; 787 the DECL_INITIAL of that decl is the CONSTRUCTOR that initializes 788 the compound literal. */ 789DEFTREECODE (COMPOUND_LITERAL_EXPR, "compound_literal_expr", tcc_expression, 1) 790 791/* Represents something we computed once and will use multiple times. 792 First operand is that expression. After it is evaluated once, it 793 will be replaced by the temporary variable that holds the value. */ 794DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1) 795 796/* & in C. Value is the address at which the operand's value resides. 797 Operand may have any mode. Result mode is Pmode. */ 798DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1) 799 800/* Operand0 is a function constant; result is part N of a function 801 descriptor of type ptr_mode. */ 802DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2) 803 804/* Given two real or integer operands of the same type, 805 returns a complex value of the corresponding complex type. */ 806DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2) 807 808/* Complex conjugate of operand. Used only on complex types. */ 809DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1) 810 811/* Nodes for ++ and -- in C. 812 The second arg is how much to increment or decrement by. 813 For a pointer, it would be the size of the object pointed to. */ 814DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2) 815DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2) 816DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2) 817DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2) 818 819/* Used to implement `va_arg'. */ 820DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1) 821 822/* Evaluate operand 1. If and only if an exception is thrown during 823 the evaluation of operand 1, evaluate operand 2. 824 825 This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated 826 on a normal or jump exit, only on an exception. */ 827DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2) 828 829/* Evaluate the first operand. 830 The second operand is a cleanup expression which is evaluated 831 on any exit (normal, exception, or jump out) from this expression. */ 832DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2) 833 834/* These types of expressions have no useful value, 835 and always have side effects. */ 836 837/* Used to represent a local declaration. The operand is DECL_EXPR_DECL. */ 838DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1) 839 840/* A label definition, encapsulated as a statement. 841 Operand 0 is the LABEL_DECL node for the label that appears here. 842 The type should be void and the value should be ignored. */ 843DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1) 844 845/* GOTO. Operand 0 is a LABEL_DECL node or an expression. 846 The type should be void and the value should be ignored. */ 847DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1) 848 849/* RETURN. Evaluates operand 0, then returns from the current function. 850 Presumably that operand is an assignment that stores into the 851 RESULT_DECL that hold the value to be returned. 852 The operand may be null. 853 The type should be void and the value should be ignored. */ 854DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1) 855 856/* Exit the inner most loop conditionally. Operand 0 is the condition. 857 The type should be void and the value should be ignored. */ 858DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1) 859 860/* A loop. Operand 0 is the body of the loop. 861 It must contain an EXIT_EXPR or is an infinite loop. 862 The type should be void and the value should be ignored. */ 863DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1) 864 865/* Switch expression. 866 867 TREE_TYPE is the original type of the condition, before any 868 language required type conversions. It may be NULL, in which case 869 the original type and final types are assumed to be the same. 870 871 Operand 0 is the expression used to perform the branch, 872 Operand 1 is the body of the switch, which probably contains 873 CASE_LABEL_EXPRs. It may also be NULL, in which case operand 2 874 must not be NULL. 875 Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs 876 of all the cases. */ 877DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3) 878 879/* Used to represent a case label. The operands are CASE_LOW and 880 CASE_HIGH, respectively. If CASE_LOW is NULL_TREE, the label is a 881 'default' label. If CASE_HIGH is NULL_TREE, the label is a normal case 882 label. CASE_LABEL is the corresponding LABEL_DECL. */ 883DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 4) 884 885/* Used to represent an inline assembly statement. ASM_STRING returns a 886 STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS, 887 ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers 888 for the statement. ASM_LABELS, if present, indicates various destinations 889 for the asm; labels cannot be combined with outputs. */ 890DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 5) 891 892/* Variable references for SSA analysis. New SSA names are created every 893 time a variable is assigned a new value. The SSA builder uses SSA_NAME 894 nodes to implement SSA versioning. */ 895DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0) 896 897/* Used to represent a typed exception handler. CATCH_TYPES is the type (or 898 list of types) handled, and CATCH_BODY is the code for the handler. */ 899DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2) 900 901/* Used to represent an exception specification. EH_FILTER_TYPES is a list 902 of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on 903 failure. */ 904DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2) 905 906/* Node used for describing a property that is known at compile 907 time. */ 908DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0) 909 910/* Node used for describing a property that is not known at compile 911 time. */ 912DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0) 913 914/* Polynomial chains of recurrences. 915 Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}. */ 916DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3) 917 918/* Used to chain children of container statements together. 919 Use the interface in tree-iterator.h to access this node. */ 920DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0) 921 922/* Predicate assertion. Artificial expression generated by the optimizers 923 to keep track of predicate values. This expression may only appear on 924 the RHS of assignments. 925 926 Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer 927 two things: 928 929 1- X is a copy of Y. 930 2- EXPR is a conditional expression and is known to be true. 931 932 Valid and to be expected forms of conditional expressions are 933 valid GIMPLE conditional expressions (as defined by is_gimple_condexpr) 934 and conditional expressions with the first operand being a 935 PLUS_EXPR with a variable possibly wrapped in a NOP_EXPR first 936 operand and an integer constant second operand. 937 938 The type of the expression is the same as Y. */ 939DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2) 940 941/* Base class information. Holds information about a class as a 942 baseclass of itself or another class. */ 943DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0) 944 945/* Records the size for an expression of variable size type. This is 946 for use in contexts in which we are accessing the entire object, 947 such as for a function call, or block copy. 948 Operand 0 is the real expression. 949 Operand 1 is the size of the type in the expression. */ 950DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2) 951 952/* Extract elements from two input vectors Operand 0 and Operand 1 953 size VS, according to the offset OFF defined by Operand 2 as 954 follows: 955 If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to 956 the first OFF elements of the vector OP1. 957 If OFF == 0, then the returned vector is OP1. 958 On different targets OFF may take different forms; It can be an address, in 959 which case its low log2(VS)-1 bits define the offset, or it can be a mask 960 generated by the builtin targetm.vectorize.mask_for_load_builtin_decl. */ 961DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3) 962 963/* Low-level memory addressing. Operands are BASE (address of static or 964 global variable or register), OFFSET (integer constant), 965 INDEX (register), STEP (integer constant), INDEX2 (register), 966 The corresponding address is BASE + STEP * INDEX + INDEX2 + OFFSET. 967 Only variations and values valid on the target are allowed. 968 969 The type of STEP, INDEX and INDEX2 is sizetype. 970 971 The type of BASE is a pointer type. If BASE is not an address of 972 a static or global variable INDEX2 will be NULL. 973 974 The type of OFFSET is a pointer type and determines TBAA the same as 975 the constant offset operand in MEM_REF. */ 976 977DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 5) 978 979/* Memory addressing. Operands are a pointer and a tree constant integer 980 byte offset of the pointer type that when dereferenced yields the 981 type of the base object the pointer points into and which is used for 982 TBAA purposes. 983 The type of the MEM_REF is the type the bytes at the memory location 984 are interpreted as. 985 MEM_REF <p, c> is equivalent to ((typeof(c))p)->x... where x... is a 986 chain of component references offsetting p by c. */ 987DEFTREECODE (MEM_REF, "mem_ref", tcc_reference, 2) 988 989/* The ordering of the codes between OMP_PARALLEL and OMP_CRITICAL is 990 exposed to TREE_RANGE_CHECK. */ 991/* OpenMP - #pragma omp parallel [clause1 ... clauseN] 992 Operand 0: OMP_PARALLEL_BODY: Code to be executed by all threads. 993 Operand 1: OMP_PARALLEL_CLAUSES: List of clauses. */ 994 995DEFTREECODE (OMP_PARALLEL, "omp_parallel", tcc_statement, 2) 996 997/* OpenMP - #pragma omp task [clause1 ... clauseN] 998 Operand 0: OMP_TASK_BODY: Code to be executed by all threads. 999 Operand 1: OMP_TASK_CLAUSES: List of clauses. */ 1000 1001DEFTREECODE (OMP_TASK, "omp_task", tcc_statement, 2) 1002 1003/* OpenMP - #pragma omp for [clause1 ... clauseN] 1004 Operand 0: OMP_FOR_BODY: Loop body. 1005 Operand 1: OMP_FOR_CLAUSES: List of clauses. 1006 Operand 2: OMP_FOR_INIT: Initialization code of the form 1007 VAR = N1. 1008 Operand 3: OMP_FOR_COND: Loop conditional expression of the form 1009 VAR { <, >, <=, >= } N2. 1010 Operand 4: OMP_FOR_INCR: Loop index increment of the form 1011 VAR { +=, -= } INCR. 1012 Operand 5: OMP_FOR_PRE_BODY: Filled by the gimplifier with things 1013 from INIT, COND, and INCR that are technically part of the 1014 OMP_FOR structured block, but are evaluated before the loop 1015 body begins. 1016 1017 VAR must be an integer or pointer variable, which is implicitly thread 1018 private. N1, N2 and INCR are required to be loop invariant integer 1019 expressions that are evaluated without any synchronization. 1020 The evaluation order, frequency of evaluation and side-effects are 1021 unspecified by the standard. */ 1022DEFTREECODE (OMP_FOR, "omp_for", tcc_statement, 6) 1023 1024/* OpenMP - #pragma omp sections [clause1 ... clauseN] 1025 Operand 0: OMP_SECTIONS_BODY: Sections body. 1026 Operand 1: OMP_SECTIONS_CLAUSES: List of clauses. */ 1027DEFTREECODE (OMP_SECTIONS, "omp_sections", tcc_statement, 2) 1028 1029/* OpenMP - #pragma omp single 1030 Operand 0: OMP_SINGLE_BODY: Single section body. 1031 Operand 1: OMP_SINGLE_CLAUSES: List of clauses. */ 1032DEFTREECODE (OMP_SINGLE, "omp_single", tcc_statement, 2) 1033 1034/* OpenMP - #pragma omp section 1035 Operand 0: OMP_SECTION_BODY: Section body. */ 1036DEFTREECODE (OMP_SECTION, "omp_section", tcc_statement, 1) 1037 1038/* OpenMP - #pragma omp master 1039 Operand 0: OMP_MASTER_BODY: Master section body. */ 1040DEFTREECODE (OMP_MASTER, "omp_master", tcc_statement, 1) 1041 1042/* OpenMP - #pragma omp ordered 1043 Operand 0: OMP_ORDERED_BODY: Master section body. */ 1044DEFTREECODE (OMP_ORDERED, "omp_ordered", tcc_statement, 1) 1045 1046/* OpenMP - #pragma omp critical [name] 1047 Operand 0: OMP_CRITICAL_BODY: Critical section body. 1048 Operand 1: OMP_CRITICAL_NAME: Identifier for critical section. */ 1049DEFTREECODE (OMP_CRITICAL, "omp_critical", tcc_statement, 2) 1050 1051/* OpenMP - #pragma omp atomic 1052 Operand 0: The address at which the atomic operation is to be performed. 1053 This address should be stabilized with save_expr. 1054 Operand 1: The expression to evaluate. When the old value of the object 1055 at the address is used in the expression, it should appear as if 1056 build_fold_indirect_ref of the address. */ 1057DEFTREECODE (OMP_ATOMIC, "omp_atomic", tcc_statement, 2) 1058 1059/* OpenMP - #pragma omp atomic read 1060 Operand 0: The address at which the atomic operation is to be performed. 1061 This address should be stabilized with save_expr. */ 1062DEFTREECODE (OMP_ATOMIC_READ, "omp_atomic_read", tcc_statement, 1) 1063 1064/* OpenMP - #pragma omp atomic capture 1065 Operand 0: The address at which the atomic operation is to be performed. 1066 This address should be stabilized with save_expr. 1067 Operand 1: The expression to evaluate. When the old value of the object 1068 at the address is used in the expression, it should appear as if 1069 build_fold_indirect_ref of the address. 1070 OMP_ATOMIC_CAPTURE_OLD returns the old memory content, 1071 OMP_ATOMIC_CAPTURE_NEW the new value. */ 1072DEFTREECODE (OMP_ATOMIC_CAPTURE_OLD, "omp_atomic_capture_old", tcc_statement, 2) 1073DEFTREECODE (OMP_ATOMIC_CAPTURE_NEW, "omp_atomic_capture_new", tcc_statement, 2) 1074 1075/* OpenMP clauses. */ 1076DEFTREECODE (OMP_CLAUSE, "omp_clause", tcc_exceptional, 0) 1077 1078/* TRANSACTION_EXPR tree code. 1079 Operand 0: BODY: contains body of the transaction. */ 1080DEFTREECODE (TRANSACTION_EXPR, "transaction_expr", tcc_expression, 1) 1081 1082/* Reduction operations. 1083 Operations that take a vector of elements and "reduce" it to a scalar 1084 result (e.g. summing the elements of the vector, finding the minimum over 1085 the vector elements, etc). 1086 Operand 0 is a vector; the first element in the vector has the result. 1087 Operand 1 is a vector. */ 1088DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1) 1089DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1) 1090DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1) 1091 1092/* Widening dot-product. 1093 The first two arguments are of type t1. 1094 The third argument and the result are of type t2, such that t2 is at least 1095 twice the size of t1. DOT_PROD_EXPR(arg1,arg2,arg3) is equivalent to: 1096 tmp = WIDEN_MULT_EXPR(arg1, arg2); 1097 arg3 = PLUS_EXPR (tmp, arg3); 1098 or: 1099 tmp = WIDEN_MULT_EXPR(arg1, arg2); 1100 arg3 = WIDEN_SUM_EXPR (tmp, arg3); */ 1101DEFTREECODE (DOT_PROD_EXPR, "dot_prod_expr", tcc_expression, 3) 1102 1103/* Widening summation. 1104 The first argument is of type t1. 1105 The second argument is of type t2, such that t2 is at least twice 1106 the size of t1. The type of the entire expression is also t2. 1107 WIDEN_SUM_EXPR is equivalent to first widening (promoting) 1108 the first argument from type t1 to type t2, and then summing it 1109 with the second argument. */ 1110DEFTREECODE (WIDEN_SUM_EXPR, "widen_sum_expr", tcc_binary, 2) 1111 1112/* Widening multiplication. 1113 The two arguments are of type t1. 1114 The result is of type t2, such that t2 is at least twice 1115 the size of t1. WIDEN_MULT_EXPR is equivalent to first widening (promoting) 1116 the arguments from type t1 to type t2, and then multiplying them. */ 1117DEFTREECODE (WIDEN_MULT_EXPR, "widen_mult_expr", tcc_binary, 2) 1118 1119/* Widening multiply-accumulate. 1120 The first two arguments are of type t1. 1121 The third argument and the result are of type t2, such as t2 is at least 1122 twice the size of t1. t1 and t2 must be integral or fixed-point types. 1123 The expression is equivalent to a WIDEN_MULT_EXPR operation 1124 of the first two operands followed by an add or subtract of the third 1125 operand. */ 1126DEFTREECODE (WIDEN_MULT_PLUS_EXPR, "widen_mult_plus_expr", tcc_expression, 3) 1127/* This is like the above, except in the final expression the multiply result 1128 is subtracted from t3. */ 1129DEFTREECODE (WIDEN_MULT_MINUS_EXPR, "widen_mult_minus_expr", tcc_expression, 3) 1130 1131/* Widening shift left. 1132 The first operand is of type t1. 1133 The second operand is the number of bits to shift by; it need not be the 1134 same type as the first operand and result. 1135 Note that the result is undefined if the second operand is larger 1136 than or equal to the first operand's type size. 1137 The type of the entire expression is t2, such that t2 is at least twice 1138 the size of t1. 1139 WIDEN_LSHIFT_EXPR is equivalent to first widening (promoting) 1140 the first argument from type t1 to type t2, and then shifting it 1141 by the second argument. */ 1142DEFTREECODE (WIDEN_LSHIFT_EXPR, "widen_lshift_expr", tcc_binary, 2) 1143 1144/* Fused multiply-add. 1145 All operands and the result are of the same type. No intermediate 1146 rounding is performed after multiplying operand one with operand two 1147 before adding operand three. */ 1148DEFTREECODE (FMA_EXPR, "fma_expr", tcc_expression, 3) 1149 1150/* Whole vector left/right shift in bits. 1151 Operand 0 is a vector to be shifted. 1152 Operand 1 is an integer shift amount in bits. */ 1153DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2) 1154DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2) 1155 1156/* Widening vector multiplication. 1157 The two operands are vectors with N elements of size S. Multiplying the 1158 elements of the two vectors will result in N products of size 2*S. 1159 VEC_WIDEN_MULT_HI_EXPR computes the N/2 high products. 1160 VEC_WIDEN_MULT_LO_EXPR computes the N/2 low products. */ 1161DEFTREECODE (VEC_WIDEN_MULT_HI_EXPR, "widen_mult_hi_expr", tcc_binary, 2) 1162DEFTREECODE (VEC_WIDEN_MULT_LO_EXPR, "widen_mult_lo_expr", tcc_binary, 2) 1163 1164/* Unpack (extract and promote/widen) the high/low elements of the input 1165 vector into the output vector. The input vector has twice as many 1166 elements as the output vector, that are half the size of the elements 1167 of the output vector. This is used to support type promotion. */ 1168DEFTREECODE (VEC_UNPACK_HI_EXPR, "vec_unpack_hi_expr", tcc_unary, 1) 1169DEFTREECODE (VEC_UNPACK_LO_EXPR, "vec_unpack_lo_expr", tcc_unary, 1) 1170 1171/* Unpack (extract) the high/low elements of the input vector, convert 1172 fixed point values to floating point and widen elements into the 1173 output vector. The input vector has twice as many elements as the output 1174 vector, that are half the size of the elements of the output vector. */ 1175DEFTREECODE (VEC_UNPACK_FLOAT_HI_EXPR, "vec_unpack_float_hi_expr", tcc_unary, 1) 1176DEFTREECODE (VEC_UNPACK_FLOAT_LO_EXPR, "vec_unpack_float_lo_expr", tcc_unary, 1) 1177 1178/* Pack (demote/narrow and merge) the elements of the two input vectors 1179 into the output vector using truncation/saturation. 1180 The elements of the input vectors are twice the size of the elements of the 1181 output vector. This is used to support type demotion. */ 1182DEFTREECODE (VEC_PACK_TRUNC_EXPR, "vec_pack_trunc_expr", tcc_binary, 2) 1183DEFTREECODE (VEC_PACK_SAT_EXPR, "vec_pack_sat_expr", tcc_binary, 2) 1184 1185/* Convert floating point values of the two input vectors to integer 1186 and pack (narrow and merge) the elements into the output vector. The 1187 elements of the input vector are twice the size of the elements of 1188 the output vector. */ 1189DEFTREECODE (VEC_PACK_FIX_TRUNC_EXPR, "vec_pack_fix_trunc_expr", tcc_binary, 2) 1190 1191/* Widening vector shift left in bits. 1192 Operand 0 is a vector to be shifted with N elements of size S. 1193 Operand 1 is an integer shift amount in bits. 1194 The result of the operation is N elements of size 2*S. 1195 VEC_WIDEN_LSHIFT_HI_EXPR computes the N/2 high results. 1196 VEC_WIDEN_LSHIFT_LO_EXPR computes the N/2 low results. 1197 */ 1198DEFTREECODE (VEC_WIDEN_LSHIFT_HI_EXPR, "widen_lshift_hi_expr", tcc_binary, 2) 1199DEFTREECODE (VEC_WIDEN_LSHIFT_LO_EXPR, "widen_lshift_lo_expr", tcc_binary, 2) 1200 1201/* PREDICT_EXPR. Specify hint for branch prediction. The 1202 PREDICT_EXPR_PREDICTOR specify predictor and PREDICT_EXPR_OUTCOME the 1203 outcome (0 for not taken and 1 for taken). Once the profile is guessed 1204 all conditional branches leading to execution paths executing the 1205 PREDICT_EXPR will get predicted by the specified predictor. */ 1206DEFTREECODE (PREDICT_EXPR, "predict_expr", tcc_expression, 1) 1207 1208/* OPTIMIZATION_NODE. Node to store the optimization options. */ 1209DEFTREECODE (OPTIMIZATION_NODE, "optimization_node", tcc_exceptional, 0) 1210 1211/* TARGET_OPTION_NODE. Node to store the target specific options. */ 1212DEFTREECODE (TARGET_OPTION_NODE, "target_option_node", tcc_exceptional, 0) 1213 1214/* 1215Local variables: 1216mode:c 1217End: 1218*/ 1219