1 /* This file contains the definitions and documentation for the 2 tree codes used in GCC. 3 Copyright (C) 1987-2013 Free Software Foundation, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along 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. */ 41 DEFTREECODE (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). */ 47 DEFTREECODE (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. */ 54 DEFTREECODE (TREE_LIST, "tree_list", tcc_exceptional, 0) 55 56 /* These nodes contain an array of tree nodes. */ 57 DEFTREECODE (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. */ 78 DEFTREECODE (BLOCK, "block", tcc_exceptional, 0) 79 80 /* 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. */ 123 DEFTREECODE (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. */ 136 DEFTREECODE (ENUMERAL_TYPE, "enumeral_type", tcc_type, 0) 137 138 /* Boolean type (true or false are the only values). Looks like an 139 INTEGRAL_TYPE. */ 140 DEFTREECODE (BOOLEAN_TYPE, "boolean_type", tcc_type, 0) 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. */ 150 DEFTREECODE (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. */ 154 DEFTREECODE (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. */ 163 DEFTREECODE (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++. */ 167 DEFTREECODE (REFERENCE_TYPE, "reference_type", tcc_type, 0) 168 169 /* The C++ decltype(nullptr) type. */ 170 DEFTREECODE (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. */ 175 DEFTREECODE (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. */ 184 DEFTREECODE (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. */ 189 DEFTREECODE (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 */ 205 DEFTREECODE (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. */ 215 DEFTREECODE (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. */ 221 DEFTREECODE (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. */ 227 DEFTREECODE (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 */ 234 DEFTREECODE (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. */ 242 DEFTREECODE (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". */ 249 DEFTREECODE (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. */ 255 DEFTREECODE (LANG_TYPE, "lang_type", tcc_type, 0) 256 257 /* Expressions */ 259 260 /* First, the constants. */ 261 262 /* Contents are in TREE_INT_CST_LOW and TREE_INT_CST_HIGH fields, 263 32 bits each, giving us a 64 bit constant capability. INTEGER_CST 264 nodes can be shared, and therefore should be considered read only. 265 They should be copied, before setting a flag such as TREE_OVERFLOW. 266 If an INTEGER_CST has TREE_OVERFLOW already set, it is known to be unique. 267 INTEGER_CST nodes are created for the integral types, for pointer 268 types and for vector and float types in some circumstances. */ 269 DEFTREECODE (INTEGER_CST, "integer_cst", tcc_constant, 0) 270 271 /* Contents are in TREE_REAL_CST field. */ 272 DEFTREECODE (REAL_CST, "real_cst", tcc_constant, 0) 273 274 /* Contents are in TREE_FIXED_CST field. */ 275 DEFTREECODE (FIXED_CST, "fixed_cst", tcc_constant, 0) 276 277 /* Contents are in TREE_REALPART and TREE_IMAGPART fields, 278 whose contents are other constant nodes. */ 279 DEFTREECODE (COMPLEX_CST, "complex_cst", tcc_constant, 0) 280 281 /* Contents are in TREE_VECTOR_CST_ELTS field. */ 282 DEFTREECODE (VECTOR_CST, "vector_cst", tcc_constant, 0) 283 284 /* Contents are TREE_STRING_LENGTH and the actual contents of the string. */ 285 DEFTREECODE (STRING_CST, "string_cst", tcc_constant, 0) 286 287 /* Declarations. All references to names are represented as ..._DECL 288 nodes. The decls in one binding context are chained through the 289 TREE_CHAIN field. Each DECL has a DECL_NAME field which contains 290 an IDENTIFIER_NODE. (Some decls, most often labels, may have zero 291 as the DECL_NAME). DECL_CONTEXT points to the node representing 292 the context in which this declaration has its scope. For 293 FIELD_DECLs, this is the RECORD_TYPE, UNION_TYPE, or 294 QUAL_UNION_TYPE node that the field is a member of. For VAR_DECL, 295 PARM_DECL, FUNCTION_DECL, LABEL_DECL, and CONST_DECL nodes, this 296 points to either the FUNCTION_DECL for the containing function, the 297 RECORD_TYPE or UNION_TYPE for the containing type, or NULL_TREE or 298 a TRANSLATION_UNIT_DECL if the given decl has "file scope". 299 DECL_ABSTRACT_ORIGIN, if non-NULL, points to the original (abstract) 300 ..._DECL node of which this decl is an (inlined or template expanded) 301 instance. 302 The TREE_TYPE field holds the data type of the object, when relevant. 303 LABEL_DECLs have no data type. For TYPE_DECL, the TREE_TYPE field 304 contents are the type whose name is being declared. 305 The DECL_ALIGN, DECL_SIZE, 306 and DECL_MODE fields exist in decl nodes just as in type nodes. 307 They are unused in LABEL_DECL, TYPE_DECL and CONST_DECL nodes. 308 309 DECL_FIELD_BIT_OFFSET holds an integer number of bits offset for 310 the location. DECL_VOFFSET holds an expression for a variable 311 offset; it is to be multiplied by DECL_VOFFSET_UNIT (an integer). 312 These fields are relevant only in FIELD_DECLs and PARM_DECLs. 313 314 DECL_INITIAL holds the value to initialize a variable to, 315 or the value of a constant. For a function, it holds the body 316 (a node of type BLOCK representing the function's binding contour 317 and whose body contains the function's statements.) For a LABEL_DECL 318 in C, it is a flag, nonzero if the label's definition has been seen. 319 320 PARM_DECLs use a special field: 321 DECL_ARG_TYPE is the type in which the argument is actually 322 passed, which may be different from its type within the function. 323 324 FUNCTION_DECLs use four special fields: 325 DECL_ARGUMENTS holds a chain of PARM_DECL nodes for the arguments. 326 DECL_RESULT holds a RESULT_DECL node for the value of a function. 327 The DECL_RTL field is 0 for a function that returns no value. 328 (C functions returning void have zero here.) 329 The TREE_TYPE field is the type in which the result is actually 330 returned. This is usually the same as the return type of the 331 FUNCTION_DECL, but it may be a wider integer type because of 332 promotion. 333 DECL_FUNCTION_CODE is a code number that is nonzero for 334 built-in functions. Its value is an enum built_in_function 335 that says which built-in function it is. 336 337 DECL_SOURCE_FILE holds a filename string and DECL_SOURCE_LINE 338 holds a line number. In some cases these can be the location of 339 a reference, if no definition has been seen. 340 341 DECL_ABSTRACT is nonzero if the decl represents an abstract instance 342 of a decl (i.e. one which is nested within an abstract instance of a 343 inline function. */ 344 345 DEFTREECODE (FUNCTION_DECL, "function_decl", tcc_declaration, 0) 346 DEFTREECODE (LABEL_DECL, "label_decl", tcc_declaration, 0) 347 /* The ordering of the following codes is optimized for the checking 348 macros in tree.h. Changing the order will degrade the speed of the 349 compiler. FIELD_DECL, VAR_DECL, CONST_DECL, PARM_DECL, 350 TYPE_DECL. */ 351 DEFTREECODE (FIELD_DECL, "field_decl", tcc_declaration, 0) 352 DEFTREECODE (VAR_DECL, "var_decl", tcc_declaration, 0) 353 DEFTREECODE (CONST_DECL, "const_decl", tcc_declaration, 0) 354 DEFTREECODE (PARM_DECL, "parm_decl", tcc_declaration, 0) 355 DEFTREECODE (TYPE_DECL, "type_decl", tcc_declaration, 0) 356 DEFTREECODE (RESULT_DECL, "result_decl", tcc_declaration, 0) 357 358 /* A "declaration" of a debug temporary. It should only appear in 359 DEBUG stmts. */ 360 DEFTREECODE (DEBUG_EXPR_DECL, "debug_expr_decl", tcc_declaration, 0) 361 362 /* A namespace declaration. Namespaces appear in DECL_CONTEXT of other 363 _DECLs, providing a hierarchy of names. */ 364 DEFTREECODE (NAMESPACE_DECL, "namespace_decl", tcc_declaration, 0) 365 366 /* A declaration import. 367 The C++ FE uses this to represent a using-directive; eg: 368 "using namespace foo". 369 But it could be used to represent any declaration import construct. 370 Whenever a declaration import appears in a lexical block, the BLOCK node 371 representing that lexical block in GIMPLE will contain an IMPORTED_DECL 372 node, linked via BLOCK_VARS accessor of the said BLOCK. 373 For a given NODE which code is IMPORTED_DECL, 374 IMPORTED_DECL_ASSOCIATED_DECL (NODE) accesses the imported declaration. */ 375 DEFTREECODE (IMPORTED_DECL, "imported_decl", tcc_declaration, 0) 376 377 /* A translation unit. This is not technically a declaration, since it 378 can't be looked up, but it's close enough. */ 379 DEFTREECODE (TRANSLATION_UNIT_DECL, "translation_unit_decl",\ 380 tcc_declaration, 0) 381 382 /* References to storage. */ 384 385 /* The ordering of the following codes is optimized for the classification 386 in handled_component_p. Keep them in a consecutive group. */ 387 388 /* Value is structure or union component. 389 Operand 0 is the structure or union (an expression). 390 Operand 1 is the field (a node of type FIELD_DECL). 391 Operand 2, if present, is the value of DECL_FIELD_OFFSET, measured 392 in units of DECL_OFFSET_ALIGN / BITS_PER_UNIT. */ 393 DEFTREECODE (COMPONENT_REF, "component_ref", tcc_reference, 3) 394 395 /* Reference to a group of bits within an object. Similar to COMPONENT_REF 396 except the position is given explicitly rather than via a FIELD_DECL. 397 Operand 0 is the structure or union expression; 398 operand 1 is a tree giving the constant number of bits being referenced; 399 operand 2 is a tree giving the constant position of the first referenced bit. 400 The result type width has to match the number of bits referenced. 401 If the result type is integral, its signedness specifies how it is extended 402 to its mode width. */ 403 DEFTREECODE (BIT_FIELD_REF, "bit_field_ref", tcc_reference, 3) 404 405 /* Array indexing. 406 Operand 0 is the array; operand 1 is a (single) array index. 407 Operand 2, if present, is a copy of TYPE_MIN_VALUE of the index. 408 Operand 3, if present, is the element size, measured in units of 409 the alignment of the element type. */ 410 DEFTREECODE (ARRAY_REF, "array_ref", tcc_reference, 4) 411 412 /* Likewise, except that the result is a range ("slice") of the array. The 413 starting index of the resulting array is taken from operand 1 and the size 414 of the range is taken from the type of the expression. */ 415 DEFTREECODE (ARRAY_RANGE_REF, "array_range_ref", tcc_reference, 4) 416 417 /* Used only on an operand of complex type, these return 418 a value of the corresponding component type. */ 419 DEFTREECODE (REALPART_EXPR, "realpart_expr", tcc_reference, 1) 420 DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", tcc_reference, 1) 421 422 /* Represents viewing something of one type as being of a second type. 423 This corresponds to an "Unchecked Conversion" in Ada and roughly to 424 the idiom *(type2 *)&X in C. The only operand is the value to be 425 viewed as being of another type. It is undefined if the type of the 426 input and of the expression have different sizes. 427 428 This code may also be used within the LHS of a MODIFY_EXPR, in which 429 case no actual data motion may occur. TREE_ADDRESSABLE will be set in 430 this case and GCC must abort if it could not do the operation without 431 generating insns. */ 432 DEFTREECODE (VIEW_CONVERT_EXPR, "view_convert_expr", tcc_reference, 1) 433 434 /* C unary `*' or Pascal `^'. One operand, an expression for a pointer. */ 435 DEFTREECODE (INDIRECT_REF, "indirect_ref", tcc_reference, 1) 436 437 /* Used to represent lookup in a virtual method table which is dependent on 438 the runtime type of an object. Operands are: 439 OBJ_TYPE_REF_EXPR: An expression that evaluates the value to use. 440 OBJ_TYPE_REF_OBJECT: Is the object on whose behalf the lookup is 441 being performed. Through this the optimizers may be able to statically 442 determine the dynamic type of the object. 443 OBJ_TYPE_REF_TOKEN: An integer index to the virtual method table. */ 444 DEFTREECODE (OBJ_TYPE_REF, "obj_type_ref", tcc_expression, 3) 445 446 /* Constructor: return an aggregate value made from specified components. 447 In C, this is used only for structure and array initializers. 448 The operand is a sequence of component values made out of a VEC of 449 struct constructor_elt. 450 451 For ARRAY_TYPE: 452 The field INDEX of each constructor_elt is the corresponding index. 453 If the index is a RANGE_EXPR, it is a short-hand for many nodes, 454 one for each index in the range. (If the corresponding field VALUE 455 has side-effects, they are evaluated once for each element. Wrap the 456 value in a SAVE_EXPR if you want to evaluate side effects only once.) 457 458 For RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE: 459 The field INDEX of each node is a FIELD_DECL. */ 460 DEFTREECODE (CONSTRUCTOR, "constructor", tcc_exceptional, 0) 461 462 /* The expression types are mostly straightforward, with the fourth argument 463 of DEFTREECODE saying how many operands there are. 464 Unless otherwise specified, the operands are expressions and the 465 types of all the operands and the expression must all be the same. */ 466 467 /* Contains two expressions to compute, one followed by the other. 468 the first value is ignored. The second one's value is used. The 469 type of the first expression need not agree with the other types. */ 470 DEFTREECODE (COMPOUND_EXPR, "compound_expr", tcc_expression, 2) 471 472 /* Assignment expression. Operand 0 is the what to set; 1, the new value. */ 473 DEFTREECODE (MODIFY_EXPR, "modify_expr", tcc_expression, 2) 474 475 /* Initialization expression. Operand 0 is the variable to initialize; 476 Operand 1 is the initializer. This differs from MODIFY_EXPR in that any 477 reference to the referent of operand 0 within operand 1 is undefined. */ 478 DEFTREECODE (INIT_EXPR, "init_expr", tcc_expression, 2) 479 480 /* For TARGET_EXPR, operand 0 is the target of an initialization, 481 operand 1 is the initializer for the target, which may be void 482 if simply expanding it initializes the target. 483 operand 2 is the cleanup for this node, if any. 484 operand 3 is the saved initializer after this node has been 485 expanded once; this is so we can re-expand the tree later. */ 486 DEFTREECODE (TARGET_EXPR, "target_expr", tcc_expression, 4) 487 488 /* Conditional expression ( ... ? ... : ... in C). 489 Operand 0 is the condition. 490 Operand 1 is the then-value. 491 Operand 2 is the else-value. 492 Operand 0 may be of any type. 493 Operand 1 must have the same type as the entire expression, unless 494 it unconditionally throws an exception, in which case it should 495 have VOID_TYPE. The same constraints apply to operand 2. The 496 condition in operand 0 must be of integral type. 497 498 In cfg gimple, if you do not have a selection expression, operands 499 1 and 2 are NULL. The operands are then taken from the cfg edges. */ 500 DEFTREECODE (COND_EXPR, "cond_expr", tcc_expression, 3) 501 502 /* Vector conditional expression. It is like COND_EXPR, but with 503 vector operands. 504 505 A = VEC_COND_EXPR ( X < Y, B, C) 506 507 means 508 509 for (i=0; i<N; i++) 510 A[i] = X[i] < Y[i] ? B[i] : C[i]; 511 */ 512 DEFTREECODE (VEC_COND_EXPR, "vec_cond_expr", tcc_expression, 3) 513 514 /* Vector permutation expression. A = VEC_PERM_EXPR<v0, v1, mask> means 515 516 N = length(mask) 517 foreach i in N: 518 M = mask[i] % (2*N) 519 A = M < N ? v0[M] : v1[M-N] 520 521 V0 and V1 are vectors of the same type. MASK is an integer-typed 522 vector. The number of MASK elements must be the same with the 523 number of elements in V0 and V1. The size of the inner type 524 of the MASK and of the V0 and V1 must be the same. 525 */ 526 DEFTREECODE (VEC_PERM_EXPR, "vec_perm_expr", tcc_expression, 3) 527 528 /* Declare local variables, including making RTL and allocating space. 529 BIND_EXPR_VARS is a chain of VAR_DECL nodes for the variables. 530 BIND_EXPR_BODY is the body, the expression to be computed using 531 the variables. The value of operand 1 becomes that of the BIND_EXPR. 532 BIND_EXPR_BLOCK is the BLOCK that corresponds to these bindings 533 for debugging purposes. If this BIND_EXPR is actually expanded, 534 that sets the TREE_USED flag in the BLOCK. 535 536 The BIND_EXPR is not responsible for informing parsers 537 about these variables. If the body is coming from the input file, 538 then the code that creates the BIND_EXPR is also responsible for 539 informing the parser of the variables. 540 541 If the BIND_EXPR is ever expanded, its TREE_USED flag is set. 542 This tells the code for debugging symbol tables not to ignore the BIND_EXPR. 543 If the BIND_EXPR should be output for debugging but will not be expanded, 544 set the TREE_USED flag by hand. 545 546 In order for the BIND_EXPR to be known at all, the code that creates it 547 must also install it as a subblock in the tree of BLOCK 548 nodes for the function. */ 549 DEFTREECODE (BIND_EXPR, "bind_expr", tcc_expression, 3) 550 551 /* Function call. CALL_EXPRs are represented by variably-sized expression 552 nodes. There are at least three fixed operands. Operand 0 is an 553 INTEGER_CST node containing the total operand count, the number of 554 arguments plus 3. Operand 1 is the function, while operand 2 is 555 is static chain argument, or NULL. The remaining operands are the 556 arguments to the call. */ 557 DEFTREECODE (CALL_EXPR, "call_expr", tcc_vl_exp, 3) 558 559 /* Specify a value to compute along with its corresponding cleanup. 560 Operand 0 is the cleanup expression. 561 The cleanup is executed by the first enclosing CLEANUP_POINT_EXPR, 562 which must exist. This differs from TRY_CATCH_EXPR in that operand 1 563 is always evaluated when cleanups are run. */ 564 DEFTREECODE (WITH_CLEANUP_EXPR, "with_cleanup_expr", tcc_expression, 1) 565 566 /* Specify a cleanup point. 567 Operand 0 is an expression that may have cleanups. If it does, those 568 cleanups are executed after the expression is expanded. 569 570 Note that if the expression is a reference to storage, it is forced out 571 of memory before the cleanups are run. This is necessary to handle 572 cases where the cleanups modify the storage referenced; in the 573 expression 't.i', if 't' is a struct with an integer member 'i' and a 574 cleanup which modifies 'i', the value of the expression depends on 575 whether the cleanup is run before or after 't.i' is evaluated. When 576 expand_expr is run on 't.i', it returns a MEM. This is not good enough; 577 the value of 't.i' must be forced out of memory. 578 579 As a consequence, the operand of a CLEANUP_POINT_EXPR must not have 580 BLKmode, because it will not be forced out of memory. */ 581 DEFTREECODE (CLEANUP_POINT_EXPR, "cleanup_point_expr", tcc_expression, 1) 582 583 /* The following code is used in languages that have types where some 584 field in an object of the type contains a value that is used in the 585 computation of another field's offset or size and/or the size of the 586 type. The positions and/or sizes of fields can vary from object to 587 object of the same type or even for one and the same object within 588 its scope. 589 590 Record types with discriminants in Ada or schema types in Pascal are 591 examples of such types. This mechanism is also used to create "fat 592 pointers" for unconstrained array types in Ada; the fat pointer is a 593 structure one of whose fields is a pointer to the actual array type 594 and the other field is a pointer to a template, which is a structure 595 containing the bounds of the array. The bounds in the type pointed 596 to by the first field in the fat pointer refer to the values in the 597 template. 598 599 When you wish to construct such a type you need "self-references" 600 that allow you to reference the object having this type from the 601 TYPE node, i.e. without having a variable instantiating this type. 602 603 Such a "self-references" is done using a PLACEHOLDER_EXPR. This is 604 a node that will later be replaced with the object being referenced. 605 Its type is that of the object and selects which object to use from 606 a chain of references (see below). No other slots are used in the 607 PLACEHOLDER_EXPR. 608 609 For example, if your type FOO is a RECORD_TYPE with a field BAR, 610 and you need the value of <variable>.BAR to calculate TYPE_SIZE 611 (FOO), just substitute <variable> above with a PLACEHOLDER_EXPR 612 whose TREE_TYPE is FOO. Then construct your COMPONENT_REF with 613 the PLACEHOLDER_EXPR as the first operand (which has the correct 614 type). Later, when the size is needed in the program, the back-end 615 will find this PLACEHOLDER_EXPR and generate code to calculate the 616 actual size at run-time. In the following, we describe how this 617 calculation is done. 618 619 When we wish to evaluate a size or offset, we check whether it contains a 620 PLACEHOLDER_EXPR. If it does, we call substitute_placeholder_in_expr 621 passing both that tree and an expression within which the object may be 622 found. The latter expression is the object itself in the simple case of 623 an Ada record with discriminant, but it can be the array in the case of an 624 unconstrained array. 625 626 In the latter case, we need the fat pointer, because the bounds of 627 the array can only be accessed from it. However, we rely here on the 628 fact that the expression for the array contains the dereference of 629 the fat pointer that obtained the array pointer. */ 630 631 /* Denotes a record to later be substituted before evaluating this expression. 632 The type of this expression is used to find the record to replace it. */ 633 DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", tcc_exceptional, 0) 634 635 /* Simple arithmetic. */ 636 DEFTREECODE (PLUS_EXPR, "plus_expr", tcc_binary, 2) 637 DEFTREECODE (MINUS_EXPR, "minus_expr", tcc_binary, 2) 638 DEFTREECODE (MULT_EXPR, "mult_expr", tcc_binary, 2) 639 640 /* Pointer addition. The first operand is always a pointer and the 641 second operand is an integer of type sizetype. */ 642 DEFTREECODE (POINTER_PLUS_EXPR, "pointer_plus_expr", tcc_binary, 2) 643 644 /* Highpart multiplication. For an integral type with precision B, 645 returns bits [2B-1, B] of the full 2*B product. */ 646 DEFTREECODE (MULT_HIGHPART_EXPR, "mult_highpart_expr", tcc_binary, 2) 647 648 /* Division for integer result that rounds the quotient toward zero. */ 649 DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", tcc_binary, 2) 650 651 /* Division for integer result that rounds the quotient toward infinity. */ 652 DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", tcc_binary, 2) 653 654 /* Division for integer result that rounds toward minus infinity. */ 655 DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", tcc_binary, 2) 656 657 /* Division for integer result that rounds toward nearest integer. */ 658 DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", tcc_binary, 2) 659 660 /* Four kinds of remainder that go with the four kinds of division. */ 661 DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", tcc_binary, 2) 662 DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", tcc_binary, 2) 663 DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", tcc_binary, 2) 664 DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", tcc_binary, 2) 665 666 /* Division for real result. */ 667 DEFTREECODE (RDIV_EXPR, "rdiv_expr", tcc_binary, 2) 668 669 /* Division which is not supposed to need rounding. 670 Used for pointer subtraction in C. */ 671 DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", tcc_binary, 2) 672 673 /* Conversion of real to fixed point by truncation. */ 674 DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", tcc_unary, 1) 675 676 /* Conversion of an integer to a real. */ 677 DEFTREECODE (FLOAT_EXPR, "float_expr", tcc_unary, 1) 678 679 /* Unary negation. */ 680 DEFTREECODE (NEGATE_EXPR, "negate_expr", tcc_unary, 1) 681 682 /* Minimum and maximum values. When used with floating point, if both 683 operands are zeros, or if either operand is NaN, then it is unspecified 684 which of the two operands is returned as the result. */ 685 DEFTREECODE (MIN_EXPR, "min_expr", tcc_binary, 2) 686 DEFTREECODE (MAX_EXPR, "max_expr", tcc_binary, 2) 687 688 /* Represents the absolute value of the operand. 689 690 An ABS_EXPR must have either an INTEGER_TYPE or a REAL_TYPE. The 691 operand of the ABS_EXPR must have the same type. */ 692 DEFTREECODE (ABS_EXPR, "abs_expr", tcc_unary, 1) 693 694 /* Shift operations for shift and rotate. 695 Shift means logical shift if done on an 696 unsigned type, arithmetic shift if done on a signed type. 697 The second operand is the number of bits to 698 shift by; it need not be the same type as the first operand and result. 699 Note that the result is undefined if the second operand is larger 700 than or equal to the first operand's type size. 701 702 The first operand of a shift can have either an integer or a 703 (non-integer) fixed-point type. We follow the ISO/IEC TR 18037:2004 704 semantics for the latter. 705 706 Rotates are defined for integer types only. */ 707 DEFTREECODE (LSHIFT_EXPR, "lshift_expr", tcc_binary, 2) 708 DEFTREECODE (RSHIFT_EXPR, "rshift_expr", tcc_binary, 2) 709 DEFTREECODE (LROTATE_EXPR, "lrotate_expr", tcc_binary, 2) 710 DEFTREECODE (RROTATE_EXPR, "rrotate_expr", tcc_binary, 2) 711 712 /* Bitwise operations. Operands have same mode as result. */ 713 DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", tcc_binary, 2) 714 DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", tcc_binary, 2) 715 DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", tcc_binary, 2) 716 DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", tcc_unary, 1) 717 718 /* ANDIF and ORIF allow the second operand not to be computed if the 719 value of the expression is determined from the first operand. AND, 720 OR, and XOR always compute the second operand whether its value is 721 needed or not (for side effects). The operand may have 722 BOOLEAN_TYPE or INTEGER_TYPE. In either case, the argument will be 723 either zero or one. For example, a TRUTH_NOT_EXPR will never have 724 an INTEGER_TYPE VAR_DECL as its argument; instead, a NE_EXPR will be 725 used to compare the VAR_DECL to zero, thereby obtaining a node with 726 value zero or one. */ 727 DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", tcc_expression, 2) 728 DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", tcc_expression, 2) 729 DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", tcc_expression, 2) 730 DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", tcc_expression, 2) 731 DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", tcc_expression, 2) 732 DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", tcc_expression, 1) 733 734 /* Relational operators. 735 `EQ_EXPR' and `NE_EXPR' are allowed for any types. 736 The others are allowed only for integer (or pointer or enumeral) 737 or real types. 738 In all cases the operands will have the same type, 739 and the value is either the type used by the language for booleans 740 or an integer vector type of the same size and with the same number 741 of elements as the comparison operands. True for a vector of 742 comparison results has all bits set while false is equal to zero. */ 743 DEFTREECODE (LT_EXPR, "lt_expr", tcc_comparison, 2) 744 DEFTREECODE (LE_EXPR, "le_expr", tcc_comparison, 2) 745 DEFTREECODE (GT_EXPR, "gt_expr", tcc_comparison, 2) 746 DEFTREECODE (GE_EXPR, "ge_expr", tcc_comparison, 2) 747 DEFTREECODE (EQ_EXPR, "eq_expr", tcc_comparison, 2) 748 DEFTREECODE (NE_EXPR, "ne_expr", tcc_comparison, 2) 749 750 /* Additional relational operators for floating point unordered. */ 751 DEFTREECODE (UNORDERED_EXPR, "unordered_expr", tcc_comparison, 2) 752 DEFTREECODE (ORDERED_EXPR, "ordered_expr", tcc_comparison, 2) 753 754 /* These are equivalent to unordered or ... */ 755 DEFTREECODE (UNLT_EXPR, "unlt_expr", tcc_comparison, 2) 756 DEFTREECODE (UNLE_EXPR, "unle_expr", tcc_comparison, 2) 757 DEFTREECODE (UNGT_EXPR, "ungt_expr", tcc_comparison, 2) 758 DEFTREECODE (UNGE_EXPR, "unge_expr", tcc_comparison, 2) 759 DEFTREECODE (UNEQ_EXPR, "uneq_expr", tcc_comparison, 2) 760 761 /* This is the reverse of uneq_expr. */ 762 DEFTREECODE (LTGT_EXPR, "ltgt_expr", tcc_comparison, 2) 763 764 DEFTREECODE (RANGE_EXPR, "range_expr", tcc_binary, 2) 765 766 /* Represents a re-association barrier for floating point expressions 767 like explicit parenthesis in fortran. */ 768 DEFTREECODE (PAREN_EXPR, "paren_expr", tcc_unary, 1) 769 770 /* Represents a conversion of type of a value. 771 All conversions, including implicit ones, must be 772 represented by CONVERT_EXPR or NOP_EXPR nodes. */ 773 DEFTREECODE (CONVERT_EXPR, "convert_expr", tcc_unary, 1) 774 775 /* Conversion of a pointer value to a pointer to a different 776 address space. */ 777 DEFTREECODE (ADDR_SPACE_CONVERT_EXPR, "addr_space_convert_expr", tcc_unary, 1) 778 779 /* Conversion of a fixed-point value to an integer, a real, or a fixed-point 780 value. Or conversion of a fixed-point value from an integer, a real, or 781 a fixed-point value. */ 782 DEFTREECODE (FIXED_CONVERT_EXPR, "fixed_convert_expr", tcc_unary, 1) 783 784 /* Represents a conversion expected to require no code to be generated. */ 785 DEFTREECODE (NOP_EXPR, "nop_expr", tcc_unary, 1) 786 787 /* Value is same as argument, but guaranteed not an lvalue. */ 788 DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", tcc_unary, 1) 789 790 /* A COMPOUND_LITERAL_EXPR represents a literal that is placed in a DECL. The 791 COMPOUND_LITERAL_EXPR_DECL_EXPR is the a DECL_EXPR containing the decl 792 for the anonymous object represented by the COMPOUND_LITERAL; 793 the DECL_INITIAL of that decl is the CONSTRUCTOR that initializes 794 the compound literal. */ 795 DEFTREECODE (COMPOUND_LITERAL_EXPR, "compound_literal_expr", tcc_expression, 1) 796 797 /* Represents something we computed once and will use multiple times. 798 First operand is that expression. After it is evaluated once, it 799 will be replaced by the temporary variable that holds the value. */ 800 DEFTREECODE (SAVE_EXPR, "save_expr", tcc_expression, 1) 801 802 /* & in C. Value is the address at which the operand's value resides. 803 Operand may have any mode. Result mode is Pmode. */ 804 DEFTREECODE (ADDR_EXPR, "addr_expr", tcc_expression, 1) 805 806 /* Operand0 is a function constant; result is part N of a function 807 descriptor of type ptr_mode. */ 808 DEFTREECODE (FDESC_EXPR, "fdesc_expr", tcc_expression, 2) 809 810 /* Given two real or integer operands of the same type, 811 returns a complex value of the corresponding complex type. */ 812 DEFTREECODE (COMPLEX_EXPR, "complex_expr", tcc_binary, 2) 813 814 /* Complex conjugate of operand. Used only on complex types. */ 815 DEFTREECODE (CONJ_EXPR, "conj_expr", tcc_unary, 1) 816 817 /* Nodes for ++ and -- in C. 818 The second arg is how much to increment or decrement by. 819 For a pointer, it would be the size of the object pointed to. */ 820 DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", tcc_expression, 2) 821 DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", tcc_expression, 2) 822 DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", tcc_expression, 2) 823 DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", tcc_expression, 2) 824 825 /* Used to implement `va_arg'. */ 826 DEFTREECODE (VA_ARG_EXPR, "va_arg_expr", tcc_expression, 1) 827 828 /* Evaluate operand 1. If and only if an exception is thrown during 829 the evaluation of operand 1, evaluate operand 2. 830 831 This differs from TRY_FINALLY_EXPR in that operand 2 is not evaluated 832 on a normal or jump exit, only on an exception. */ 833 DEFTREECODE (TRY_CATCH_EXPR, "try_catch_expr", tcc_statement, 2) 834 835 /* Evaluate the first operand. 836 The second operand is a cleanup expression which is evaluated 837 on any exit (normal, exception, or jump out) from this expression. */ 838 DEFTREECODE (TRY_FINALLY_EXPR, "try_finally", tcc_statement, 2) 839 840 /* These types of expressions have no useful value, 842 and always have side effects. */ 843 844 /* Used to represent a local declaration. The operand is DECL_EXPR_DECL. */ 845 DEFTREECODE (DECL_EXPR, "decl_expr", tcc_statement, 1) 846 847 /* A label definition, encapsulated as a statement. 848 Operand 0 is the LABEL_DECL node for the label that appears here. 849 The type should be void and the value should be ignored. */ 850 DEFTREECODE (LABEL_EXPR, "label_expr", tcc_statement, 1) 851 852 /* GOTO. Operand 0 is a LABEL_DECL node or an expression. 853 The type should be void and the value should be ignored. */ 854 DEFTREECODE (GOTO_EXPR, "goto_expr", tcc_statement, 1) 855 856 /* RETURN. Evaluates operand 0, then returns from the current function. 857 Presumably that operand is an assignment that stores into the 858 RESULT_DECL that hold the value to be returned. 859 The operand may be null. 860 The type should be void and the value should be ignored. */ 861 DEFTREECODE (RETURN_EXPR, "return_expr", tcc_statement, 1) 862 863 /* Exit the inner most loop conditionally. Operand 0 is the condition. 864 The type should be void and the value should be ignored. */ 865 DEFTREECODE (EXIT_EXPR, "exit_expr", tcc_statement, 1) 866 867 /* A loop. Operand 0 is the body of the loop. 868 It must contain an EXIT_EXPR or is an infinite loop. 869 The type should be void and the value should be ignored. */ 870 DEFTREECODE (LOOP_EXPR, "loop_expr", tcc_statement, 1) 871 872 /* Switch expression. 873 874 TREE_TYPE is the original type of the condition, before any 875 language required type conversions. It may be NULL, in which case 876 the original type and final types are assumed to be the same. 877 878 Operand 0 is the expression used to perform the branch, 879 Operand 1 is the body of the switch, which probably contains 880 CASE_LABEL_EXPRs. It may also be NULL, in which case operand 2 881 must not be NULL. 882 Operand 2 is either NULL_TREE or a TREE_VEC of the CASE_LABEL_EXPRs 883 of all the cases. */ 884 DEFTREECODE (SWITCH_EXPR, "switch_expr", tcc_statement, 3) 885 886 /* Used to represent a case label. 887 888 Operand 0 is CASE_LOW. It may be NULL_TREE, in which case the label 889 is a 'default' label. 890 Operand 1 is CASE_HIGH. If it is NULL_TREE, the label is a simple 891 (one-value) case label. If it is non-NULL_TREE, the case is a range. 892 Operand 2 is CASE_LABEL, which is is the corresponding LABEL_DECL. 893 Operand 4 is CASE_CHAIN. This operand is only used in tree-cfg.c to 894 speed up the lookup of case labels which use a particular edge in 895 the control flow graph. */ 896 DEFTREECODE (CASE_LABEL_EXPR, "case_label_expr", tcc_statement, 4) 897 898 /* Used to represent an inline assembly statement. ASM_STRING returns a 899 STRING_CST for the instruction (e.g., "mov x, y"). ASM_OUTPUTS, 900 ASM_INPUTS, and ASM_CLOBBERS represent the outputs, inputs, and clobbers 901 for the statement. ASM_LABELS, if present, indicates various destinations 902 for the asm; labels cannot be combined with outputs. */ 903 DEFTREECODE (ASM_EXPR, "asm_expr", tcc_statement, 5) 904 905 /* Variable references for SSA analysis. New SSA names are created every 906 time a variable is assigned a new value. The SSA builder uses SSA_NAME 907 nodes to implement SSA versioning. */ 908 DEFTREECODE (SSA_NAME, "ssa_name", tcc_exceptional, 0) 909 910 /* Used to represent a typed exception handler. CATCH_TYPES is the type (or 911 list of types) handled, and CATCH_BODY is the code for the handler. */ 912 DEFTREECODE (CATCH_EXPR, "catch_expr", tcc_statement, 2) 913 914 /* Used to represent an exception specification. EH_FILTER_TYPES is a list 915 of allowed types, and EH_FILTER_FAILURE is an expression to evaluate on 916 failure. */ 917 DEFTREECODE (EH_FILTER_EXPR, "eh_filter_expr", tcc_statement, 2) 918 919 /* Node used for describing a property that is known at compile 920 time. */ 921 DEFTREECODE (SCEV_KNOWN, "scev_known", tcc_expression, 0) 922 923 /* Node used for describing a property that is not known at compile 924 time. */ 925 DEFTREECODE (SCEV_NOT_KNOWN, "scev_not_known", tcc_expression, 0) 926 927 /* Polynomial chains of recurrences. 928 Under the form: cr = {CHREC_LEFT (cr), +, CHREC_RIGHT (cr)}. */ 929 DEFTREECODE (POLYNOMIAL_CHREC, "polynomial_chrec", tcc_expression, 3) 930 931 /* Used to chain children of container statements together. 932 Use the interface in tree-iterator.h to access this node. */ 933 DEFTREECODE (STATEMENT_LIST, "statement_list", tcc_exceptional, 0) 934 935 /* Predicate assertion. Artificial expression generated by the optimizers 936 to keep track of predicate values. This expression may only appear on 937 the RHS of assignments. 938 939 Given X = ASSERT_EXPR <Y, EXPR>, the optimizers can infer 940 two things: 941 942 1- X is a copy of Y. 943 2- EXPR is a conditional expression and is known to be true. 944 945 Valid and to be expected forms of conditional expressions are 946 valid GIMPLE conditional expressions (as defined by is_gimple_condexpr) 947 and conditional expressions with the first operand being a 948 PLUS_EXPR with a variable possibly wrapped in a NOP_EXPR first 949 operand and an integer constant second operand. 950 951 The type of the expression is the same as Y. */ 952 DEFTREECODE (ASSERT_EXPR, "assert_expr", tcc_expression, 2) 953 954 /* Base class information. Holds information about a class as a 955 baseclass of itself or another class. */ 956 DEFTREECODE (TREE_BINFO, "tree_binfo", tcc_exceptional, 0) 957 958 /* Records the size for an expression of variable size type. This is 959 for use in contexts in which we are accessing the entire object, 960 such as for a function call, or block copy. 961 Operand 0 is the real expression. 962 Operand 1 is the size of the type in the expression. */ 963 DEFTREECODE (WITH_SIZE_EXPR, "with_size_expr", tcc_expression, 2) 964 965 /* Extract elements from two input vectors Operand 0 and Operand 1 966 size VS, according to the offset OFF defined by Operand 2 as 967 follows: 968 If OFF > 0, the last VS - OFF elements of vector OP0 are concatenated to 969 the first OFF elements of the vector OP1. 970 If OFF == 0, then the returned vector is OP1. 971 On different targets OFF may take different forms; It can be an address, in 972 which case its low log2(VS)-1 bits define the offset, or it can be a mask 973 generated by the builtin targetm.vectorize.mask_for_load_builtin_decl. */ 974 DEFTREECODE (REALIGN_LOAD_EXPR, "realign_load", tcc_expression, 3) 975 976 /* Low-level memory addressing. Operands are BASE (address of static or 977 global variable or register), OFFSET (integer constant), 978 INDEX (register), STEP (integer constant), INDEX2 (register), 979 The corresponding address is BASE + STEP * INDEX + INDEX2 + OFFSET. 980 Only variations and values valid on the target are allowed. 981 982 The type of STEP, INDEX and INDEX2 is sizetype. 983 984 The type of BASE is a pointer type. If BASE is not an address of 985 a static or global variable INDEX2 will be NULL. 986 987 The type of OFFSET is a pointer type and determines TBAA the same as 988 the constant offset operand in MEM_REF. */ 989 990 DEFTREECODE (TARGET_MEM_REF, "target_mem_ref", tcc_reference, 5) 991 992 /* Memory addressing. Operands are a pointer and a tree constant integer 993 byte offset of the pointer type that when dereferenced yields the 994 type of the base object the pointer points into and which is used for 995 TBAA purposes. 996 The type of the MEM_REF is the type the bytes at the memory location 997 are interpreted as. 998 MEM_REF <p, c> is equivalent to ((typeof(c))p)->x... where x... is a 999 chain of component references offsetting p by c. */ 1000 DEFTREECODE (MEM_REF, "mem_ref", tcc_reference, 2) 1001 1002 /* The ordering of the codes between OMP_PARALLEL and OMP_CRITICAL is 1003 exposed to TREE_RANGE_CHECK. */ 1004 /* OpenMP - #pragma omp parallel [clause1 ... clauseN] 1005 Operand 0: OMP_PARALLEL_BODY: Code to be executed by all threads. 1006 Operand 1: OMP_PARALLEL_CLAUSES: List of clauses. */ 1007 1008 DEFTREECODE (OMP_PARALLEL, "omp_parallel", tcc_statement, 2) 1009 1010 /* OpenMP - #pragma omp task [clause1 ... clauseN] 1011 Operand 0: OMP_TASK_BODY: Code to be executed by all threads. 1012 Operand 1: OMP_TASK_CLAUSES: List of clauses. */ 1013 1014 DEFTREECODE (OMP_TASK, "omp_task", tcc_statement, 2) 1015 1016 /* OpenMP - #pragma omp for [clause1 ... clauseN] 1017 Operand 0: OMP_FOR_BODY: Loop body. 1018 Operand 1: OMP_FOR_CLAUSES: List of clauses. 1019 Operand 2: OMP_FOR_INIT: Initialization code of the form 1020 VAR = N1. 1021 Operand 3: OMP_FOR_COND: Loop conditional expression of the form 1022 VAR { <, >, <=, >= } N2. 1023 Operand 4: OMP_FOR_INCR: Loop index increment of the form 1024 VAR { +=, -= } INCR. 1025 Operand 5: OMP_FOR_PRE_BODY: Filled by the gimplifier with things 1026 from INIT, COND, and INCR that are technically part of the 1027 OMP_FOR structured block, but are evaluated before the loop 1028 body begins. 1029 1030 VAR must be an integer or pointer variable, which is implicitly thread 1031 private. N1, N2 and INCR are required to be loop invariant integer 1032 expressions that are evaluated without any synchronization. 1033 The evaluation order, frequency of evaluation and side-effects are 1034 unspecified by the standard. */ 1035 DEFTREECODE (OMP_FOR, "omp_for", tcc_statement, 6) 1036 1037 /* OpenMP - #pragma omp sections [clause1 ... clauseN] 1038 Operand 0: OMP_SECTIONS_BODY: Sections body. 1039 Operand 1: OMP_SECTIONS_CLAUSES: List of clauses. */ 1040 DEFTREECODE (OMP_SECTIONS, "omp_sections", tcc_statement, 2) 1041 1042 /* OpenMP - #pragma omp single 1043 Operand 0: OMP_SINGLE_BODY: Single section body. 1044 Operand 1: OMP_SINGLE_CLAUSES: List of clauses. */ 1045 DEFTREECODE (OMP_SINGLE, "omp_single", tcc_statement, 2) 1046 1047 /* OpenMP - #pragma omp section 1048 Operand 0: OMP_SECTION_BODY: Section body. */ 1049 DEFTREECODE (OMP_SECTION, "omp_section", tcc_statement, 1) 1050 1051 /* OpenMP - #pragma omp master 1052 Operand 0: OMP_MASTER_BODY: Master section body. */ 1053 DEFTREECODE (OMP_MASTER, "omp_master", tcc_statement, 1) 1054 1055 /* OpenMP - #pragma omp ordered 1056 Operand 0: OMP_ORDERED_BODY: Master section body. */ 1057 DEFTREECODE (OMP_ORDERED, "omp_ordered", tcc_statement, 1) 1058 1059 /* OpenMP - #pragma omp critical [name] 1060 Operand 0: OMP_CRITICAL_BODY: Critical section body. 1061 Operand 1: OMP_CRITICAL_NAME: Identifier for critical section. */ 1062 DEFTREECODE (OMP_CRITICAL, "omp_critical", tcc_statement, 2) 1063 1064 /* OpenMP - #pragma omp atomic 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 DEFTREECODE (OMP_ATOMIC, "omp_atomic", tcc_statement, 2) 1071 1072 /* OpenMP - #pragma omp atomic read 1073 Operand 0: The address at which the atomic operation is to be performed. 1074 This address should be stabilized with save_expr. */ 1075 DEFTREECODE (OMP_ATOMIC_READ, "omp_atomic_read", tcc_statement, 1) 1076 1077 /* OpenMP - #pragma omp atomic capture 1078 Operand 0: The address at which the atomic operation is to be performed. 1079 This address should be stabilized with save_expr. 1080 Operand 1: The expression to evaluate. When the old value of the object 1081 at the address is used in the expression, it should appear as if 1082 build_fold_indirect_ref of the address. 1083 OMP_ATOMIC_CAPTURE_OLD returns the old memory content, 1084 OMP_ATOMIC_CAPTURE_NEW the new value. */ 1085 DEFTREECODE (OMP_ATOMIC_CAPTURE_OLD, "omp_atomic_capture_old", tcc_statement, 2) 1086 DEFTREECODE (OMP_ATOMIC_CAPTURE_NEW, "omp_atomic_capture_new", tcc_statement, 2) 1087 1088 /* OpenMP clauses. */ 1089 DEFTREECODE (OMP_CLAUSE, "omp_clause", tcc_exceptional, 0) 1090 1091 /* TRANSACTION_EXPR tree code. 1092 Operand 0: BODY: contains body of the transaction. */ 1093 DEFTREECODE (TRANSACTION_EXPR, "transaction_expr", tcc_expression, 1) 1094 1095 /* Reduction operations. 1096 Operations that take a vector of elements and "reduce" it to a scalar 1097 result (e.g. summing the elements of the vector, finding the minimum over 1098 the vector elements, etc). 1099 Operand 0 is a vector. 1100 The expression returns a vector of the same type, with the first 1101 element in the vector holding the result of the reduction of all elements 1102 of the operand. The content of the other elements in the returned vector 1103 is undefined. */ 1104 DEFTREECODE (REDUC_MAX_EXPR, "reduc_max_expr", tcc_unary, 1) 1105 DEFTREECODE (REDUC_MIN_EXPR, "reduc_min_expr", tcc_unary, 1) 1106 DEFTREECODE (REDUC_PLUS_EXPR, "reduc_plus_expr", tcc_unary, 1) 1107 1108 /* Widening dot-product. 1109 The first two arguments are of type t1. 1110 The third argument and the result are of type t2, such that t2 is at least 1111 twice the size of t1. DOT_PROD_EXPR(arg1,arg2,arg3) is equivalent to: 1112 tmp = WIDEN_MULT_EXPR(arg1, arg2); 1113 arg3 = PLUS_EXPR (tmp, arg3); 1114 or: 1115 tmp = WIDEN_MULT_EXPR(arg1, arg2); 1116 arg3 = WIDEN_SUM_EXPR (tmp, arg3); */ 1117 DEFTREECODE (DOT_PROD_EXPR, "dot_prod_expr", tcc_expression, 3) 1118 1119 /* Widening summation. 1120 The first argument is of type t1. 1121 The second argument is of type t2, such that t2 is at least twice 1122 the size of t1. The type of the entire expression is also t2. 1123 WIDEN_SUM_EXPR is equivalent to first widening (promoting) 1124 the first argument from type t1 to type t2, and then summing it 1125 with the second argument. */ 1126 DEFTREECODE (WIDEN_SUM_EXPR, "widen_sum_expr", tcc_binary, 2) 1127 1128 /* Widening multiplication. 1129 The two arguments are of type t1. 1130 The result is of type t2, such that t2 is at least twice 1131 the size of t1. WIDEN_MULT_EXPR is equivalent to first widening (promoting) 1132 the arguments from type t1 to type t2, and then multiplying them. */ 1133 DEFTREECODE (WIDEN_MULT_EXPR, "widen_mult_expr", tcc_binary, 2) 1134 1135 /* Widening multiply-accumulate. 1136 The first two arguments are of type t1. 1137 The third argument and the result are of type t2, such as t2 is at least 1138 twice the size of t1. t1 and t2 must be integral or fixed-point types. 1139 The expression is equivalent to a WIDEN_MULT_EXPR operation 1140 of the first two operands followed by an add or subtract of the third 1141 operand. */ 1142 DEFTREECODE (WIDEN_MULT_PLUS_EXPR, "widen_mult_plus_expr", tcc_expression, 3) 1143 /* This is like the above, except in the final expression the multiply result 1144 is subtracted from t3. */ 1145 DEFTREECODE (WIDEN_MULT_MINUS_EXPR, "widen_mult_minus_expr", tcc_expression, 3) 1146 1147 /* Widening shift left. 1148 The first operand is of type t1. 1149 The second operand is the number of bits to shift by; it need not be the 1150 same type as the first operand and result. 1151 Note that the result is undefined if the second operand is larger 1152 than or equal to the first operand's type size. 1153 The type of the entire expression is t2, such that t2 is at least twice 1154 the size of t1. 1155 WIDEN_LSHIFT_EXPR is equivalent to first widening (promoting) 1156 the first argument from type t1 to type t2, and then shifting it 1157 by the second argument. */ 1158 DEFTREECODE (WIDEN_LSHIFT_EXPR, "widen_lshift_expr", tcc_binary, 2) 1159 1160 /* Fused multiply-add. 1161 All operands and the result are of the same type. No intermediate 1162 rounding is performed after multiplying operand one with operand two 1163 before adding operand three. */ 1164 DEFTREECODE (FMA_EXPR, "fma_expr", tcc_expression, 3) 1165 1166 /* Whole vector left/right shift in bits. 1167 Operand 0 is a vector to be shifted. 1168 Operand 1 is an integer shift amount in bits. */ 1169 DEFTREECODE (VEC_LSHIFT_EXPR, "vec_lshift_expr", tcc_binary, 2) 1170 DEFTREECODE (VEC_RSHIFT_EXPR, "vec_rshift_expr", tcc_binary, 2) 1171 1172 /* Widening vector multiplication. 1174 The two operands are vectors with N elements of size S. Multiplying the 1175 elements of the two vectors will result in N products of size 2*S. 1176 VEC_WIDEN_MULT_HI_EXPR computes the N/2 high products. 1177 VEC_WIDEN_MULT_LO_EXPR computes the N/2 low products. */ 1178 DEFTREECODE (VEC_WIDEN_MULT_HI_EXPR, "widen_mult_hi_expr", tcc_binary, 2) 1179 DEFTREECODE (VEC_WIDEN_MULT_LO_EXPR, "widen_mult_lo_expr", tcc_binary, 2) 1180 1181 /* Similarly, but return the even or odd N/2 products. */ 1182 DEFTREECODE (VEC_WIDEN_MULT_EVEN_EXPR, "widen_mult_even_expr", tcc_binary, 2) 1183 DEFTREECODE (VEC_WIDEN_MULT_ODD_EXPR, "widen_mult_odd_expr", tcc_binary, 2) 1184 1185 /* Unpack (extract and promote/widen) the high/low elements of the input 1186 vector into the output vector. The input vector has twice as many 1187 elements as the output vector, that are half the size of the elements 1188 of the output vector. This is used to support type promotion. */ 1189 DEFTREECODE (VEC_UNPACK_HI_EXPR, "vec_unpack_hi_expr", tcc_unary, 1) 1190 DEFTREECODE (VEC_UNPACK_LO_EXPR, "vec_unpack_lo_expr", tcc_unary, 1) 1191 1192 /* Unpack (extract) the high/low elements of the input vector, convert 1193 fixed point values to floating point and widen elements into the 1194 output vector. The input vector has twice as many elements as the output 1195 vector, that are half the size of the elements of the output vector. */ 1196 DEFTREECODE (VEC_UNPACK_FLOAT_HI_EXPR, "vec_unpack_float_hi_expr", tcc_unary, 1) 1197 DEFTREECODE (VEC_UNPACK_FLOAT_LO_EXPR, "vec_unpack_float_lo_expr", tcc_unary, 1) 1198 1199 /* Pack (demote/narrow and merge) the elements of the two input vectors 1200 into the output vector using truncation/saturation. 1201 The elements of the input vectors are twice the size of the elements of the 1202 output vector. This is used to support type demotion. */ 1203 DEFTREECODE (VEC_PACK_TRUNC_EXPR, "vec_pack_trunc_expr", tcc_binary, 2) 1204 DEFTREECODE (VEC_PACK_SAT_EXPR, "vec_pack_sat_expr", tcc_binary, 2) 1205 1206 /* Convert floating point values of the two input vectors to integer 1207 and pack (narrow and merge) the elements into the output vector. The 1208 elements of the input vector are twice the size of the elements of 1209 the output vector. */ 1210 DEFTREECODE (VEC_PACK_FIX_TRUNC_EXPR, "vec_pack_fix_trunc_expr", tcc_binary, 2) 1211 1212 /* Widening vector shift left in bits. 1213 Operand 0 is a vector to be shifted with N elements of size S. 1214 Operand 1 is an integer shift amount in bits. 1215 The result of the operation is N elements of size 2*S. 1216 VEC_WIDEN_LSHIFT_HI_EXPR computes the N/2 high results. 1217 VEC_WIDEN_LSHIFT_LO_EXPR computes the N/2 low results. 1218 */ 1219 DEFTREECODE (VEC_WIDEN_LSHIFT_HI_EXPR, "widen_lshift_hi_expr", tcc_binary, 2) 1220 DEFTREECODE (VEC_WIDEN_LSHIFT_LO_EXPR, "widen_lshift_lo_expr", tcc_binary, 2) 1221 1222 /* PREDICT_EXPR. Specify hint for branch prediction. The 1223 PREDICT_EXPR_PREDICTOR specify predictor and PREDICT_EXPR_OUTCOME the 1224 outcome (0 for not taken and 1 for taken). Once the profile is guessed 1225 all conditional branches leading to execution paths executing the 1226 PREDICT_EXPR will get predicted by the specified predictor. */ 1227 DEFTREECODE (PREDICT_EXPR, "predict_expr", tcc_expression, 1) 1228 1229 /* OPTIMIZATION_NODE. Node to store the optimization options. */ 1230 DEFTREECODE (OPTIMIZATION_NODE, "optimization_node", tcc_exceptional, 0) 1231 1232 /* TARGET_OPTION_NODE. Node to store the target specific options. */ 1233 DEFTREECODE (TARGET_OPTION_NODE, "target_option_node", tcc_exceptional, 0) 1234 1235 /* 1236 Local variables: 1237 mode:c 1238 End: 1239 */ 1240
