1 /* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
2 ** All rights reserved.
4 ** Authors: Martin Trapp, Christian Schaefer,
7 ** ircons.h ir node construction
12 *** Ideas for imrovement:
14 Handle construction of exceptions more comfortable:
15 Add new constructors that pass the exception region (or better the
16 Phi for the memories, the ex. region can be found from there) as parameter,
17 constructor then adds all Proj nodes and returns the pointer
18 to the Proj node that selects the result of the arithmetic operation.
20 Maybe hide the exception region in a global variable, especially if
21 it is always unambiguous.
27 This file documents all datatypes and constructors needed to
28 build a FIRM representation of a pocedure. The constructors are
29 also implemented in this file.
31 The documentation also gives a short manual how to use the library.
33 For extensive documentation of FIRM see UKA Techreport 1999-14.
41 This struct contains all information about a procedure.
42 It's allocated directly to memory.
44 The fields of ir_graph:
46 *ent The entity describing this procedure.
48 The beginning and end of a graph:
50 *start_block This ir_node is the block that contains the unique
51 start node of the procedure. With it it contains
52 the Proj's on starts results.
53 Further all Const nodes are placed in the start block.
54 *start This ir_node is the unique start node of the procedure.
56 *end_block This ir_node is the block that contains the unique
57 end node of the procedure. This block contains no
59 *end This ir_node is the unique end node of the procedure.
61 The following nodes are Projs from the start node, held in ir_graph for
64 *frame The ir_node producing the pointer to the stack frame of
65 the procedure as output. This is the Proj node on the
66 third output of the start node. This output of the start
67 node is tagged as pns_frame_base. In FIRM most lokal
68 variables are modeled as data flow edges. Static
69 allocated arrays can not be represented as dataflow
70 edges. Therefore FIRM has to represent them in the stack
73 *globals This models a pointer to a space in the memory where
74 _all_ global things are held. Select from this pointer
75 with a Sel node the pointer to a global variable /
76 procedure / compiler known function... .
78 *args The ir_node that produces the arguments of the method as
79 it's result. This is a Proj node on the fourth output of
80 the start node. This output is tagged as pns_args.
82 *bad The bad node is an auxiliary node. It is needed only once,
83 so there is this globally reachable node.
85 Datastructures that are private to a graph:
87 *obst An obstack that contains all nodes.
89 *current_block A pointer to the current block. Any node created with
90 one of the node constructors (new_<opcode>) are assigned
91 to this block. It can be set with switch_block(block).
92 Only needed for ir construction.
94 params/n_loc An int giving the number of local variables in this
95 procedure. This is neede for ir construction. Name will
98 *value_table This hash table (pset) is used for global value numbering
99 for optimizing use in iropt.c.
101 *Phi_in_stack; a stack needed for automatic Phi construction, needed only
102 during ir construction.
108 There are three kinds of nodes known to the ir: entities,
111 + ir_nodes are the actual nodes of the FIRM intermediate representation.
112 They represent operations on the data of the program and control flow
115 + entity ==> implemented in entity.h
116 Refers to a single entity of the compiled program, e.g. a field of a
117 class or a method. If a method or variable can not be assigned to
118 a method or class or the like, it is a global object.
120 + types ==> implemented in type.h
121 With types type information is represented. There are several type
124 Implementation of the FIRM operations: ir_node
125 ----------------------------------------------
127 Ir_nodes represent operations on the data of the program and control flow
128 operations. Examples of ir_nodes: Add, Jmp, Cmp
130 FIRM is a dataflow graph. A dataflow graph is a directed graph,
131 so that every node has incoming and outgoing edges. A node is
132 executable if every input at it's incoming edges is available.
133 Execution of the dataflow graph is started at the Start node which
134 has no incoming edges and ends when the End node executes, even if
135 there are still executable or not executed nodes. (Is this true,
136 or must all executable nodes be executed?) (There are exceptions
137 to the dataflow paradigma that all inputs have to be available
138 before a node can execute: Phi, Block. See UKA Techreport
141 The implementation of FIRM differs from the view as a dataflow
142 graph. To allow fast traversion of the graph edges are
143 implemented as C-pointers. Inputs to nodes are not ambiguous, the
144 results can be used by several other nodes. Each input can be
145 implemented as a single pointer to a predecessor node, outputs
146 need to be lists of pointers to successors. Therefore a node
147 contains pointers to it's predecessor so that the implementation is a
148 dataflow graph with reversed edges. It has to be traversed bottom
151 All nodes of the ir have the same basic structure. They are
152 distinguished by a field containing the opcode.
154 The fields of an ir_node:
156 kind A firm_kind tag containing k_ir_node. This is useful for
157 dynamically checking the type of a node.
159 *op This ir_op gives the opcode as a tag and a string
160 and the number of attributes of an ir_node. There is
161 one statically allocated struct ir_op for each opcode.
163 *mode The ir_mode of the operation represented by this firm
164 node. The mode of the operation is the mode of it's
165 result. A Firm mode is a datatype as known to the target,
166 not a type of the source language.
168 visit A flag for traversing the ir.
170 **in An array with pointers to the node's predecessors.
172 *link A pointer to an ir_node. With this pointer all Phi nodes
173 are attached to a Block, i.e., a Block points to it's
174 first Phi node, this node points to the second Phi node
175 in the Block and so fourth. Used in mature_block
176 to find all Phi nodes to be matured. It's also used to
177 annotate a node with a better, optimized version of it.
179 attr An attr struct containing the attributes of the nodes. The
180 attributes depend on the opcode of the node. The number
181 of these attributes is given in op.
185 Not yet documented. See irop.h.
189 Not yet documented. See irmode.h.
194 current_ir_graph Points to the current ir_graph. All constructors for
195 nodes add nodes to this graph.
197 ir_visited An int used as flag to traverse the ir_graph.
199 block_visited An int used as a flag to traverse block nodes in the
202 Others not yet documented.
207 CONSTRUCTOR FOR IR_GRAPH
208 ========================
210 ir_graph *new_ir_graph (entity *ent, int params);
211 -------------------------------------------------
213 This constructor generates the basic infrastructure needed to
214 represent a procedure in FIRM.
216 The parameters of new_ir_graph are:
218 *ent A pointer to an entity representing the procedure.
220 params An integer giving the number of local variables in the
223 It allocates an ir_graph and sets current_ir_graph to point to this
224 graph. Further it allocates the following nodes needed for every
227 * The start block containing a start node and Proj nodes for it's
228 five results (X, M, P, P, T).
229 * The end block containing an end node. This block is not matured
230 after executing new_ir_graph as predecessors need to be added to it.
231 (Maturing a block means fixing it's number of predecessors.)
232 * The current block, which is empty and also not matured.
234 Further it enters the global store into the datastructure of the start
235 block that contanis all valid values in this block (set_store()). This
236 datastructure is used to build the Phi nodes and removed after completion
238 There is no path from end to start in the graph after calling ir_graph.
241 PROCEDURE TO CONSTRUCT AN IR GRAPH
242 ==================================
244 This library supplies several interfaces to construct a FIRM graph for
246 * A "comfortable" interface generating SSA automatically. Automatically
247 computed predecessors of nodes need not be specified in the constructors.
248 (new_<Node> constructurs and a set of additional routines.)
249 * A less comfortable interface where all predecessors except the block
250 an operation belongs to need to be specified. SSA must be constructed
251 by hand. (new_<Node> constructors and switch_block()). This interface
252 is called "block oriented".
253 * An even less comfortable interface where the block needs to be specified
254 explicitly. This is called the "raw" interface. (new_r_<Node>
257 To use the functionality of the comfortable interface correctly the Front
258 End needs to follow certain protocols. This is explained in the following.
259 To build a correct IR with the other interfaces study the semantics of
260 the firm node (See tech-reprot UKA 1999-44). For the construction of
261 types and entities see the documentation in those modules.
263 First the Frontend needs to decide which variables and values used in
264 a procedure can be represented by dataflow edges. These are variables
265 that need not be saved to memory as they cause no side effects visible
266 out of the procedure. In general these are all compiler generated
267 variables and simple local variables of the procedure as integers,
268 reals and pointers. The frontend has to count and number these variables.
270 First an ir_graph needs to be constructed with new_ir_graph. The
271 constructor gets the number of local variables. The graph is hold in the
274 Now the construction of the procedure can start. Several basic blocks can
275 be constructed in parallel, but the code within each block needs to
276 be constructed (almost) in program order.
278 A global variable holds the current basic block. All (non block) nodes
279 generated are added to this block. The current block can be set with
280 switch_block(block). If several blocks are constructed in parallel block
281 switches need to be performed constantly.
283 To generate a Block node (with the comfortable interface) it's predecessor
284 control flow nodes need not be known. In case of cyclic control flow these
285 can not be known when the block is constructed. With add_in_edge(block,
286 cfnode) predecessors can be added to the block. If all predecessors are
287 added to the block mature_block(b) needs to be called. Calling mature_block
288 early improves the efficiency of the Phi node construction algorithm.
289 But if several blocks are constructed at once, mature_block must only
290 be called after performing all set_values and set_stores in the block!
291 (See documentation of new_immBlock constructor.)
293 The constructors of arithmetic nodes require that their predecessors
294 are mentioned. Sometimes these are available in the Frontend as the
295 predecessors have just been generated by the frontend. If they are local
296 values the predecessors can be obtained from the library with a call to
297 get_value(local_val_nr). (local_val_nr needs to be administered by
298 the Frontend.) A call to get_value triggers the generation of Phi nodes.
299 If an arithmetic operation produces a local value this value needs to be
300 passed to the library by set_value(node, local_val_nr).
301 In straight line code these two operations just remember and return the
302 pointer to nodes producing the value. If the value passes block boundaries
303 Phi nodes can be inserted.
304 Similar routines exist to manage the Memory operands: set_store and
307 Several nodes produce more than one result. An example is the Div node.
308 Such nodes return tuples of values. From these individual values can be
309 extracted by proj nodes.
311 The following example illustrates the construction of a simple basic block
312 with two predecessors stored in variables cf_pred1 and cf_pred2, containing
315 and finally jumping to an other block. The variable a got the local_val_nr
318 ir_node *this_block, *cf_pred1, *cf_pred2, *a_val, *mem, *div, *res, *cf_op;
320 this_block = new_immBlock();
321 add_in_edge(this_block, cf_pred1);
322 add_in_edge(this_block, cf_pred2);
323 mature_block(this_block);
324 a_val = get_value(17, mode_I);
326 div = new_Div(mem, a_val, a_val);
327 mem = new_Proj(div, mode_M, 0); * for the numbers for Proj see docu *
328 res = new_Proj(div, mode_I, 2);
333 For further information look at the documentation of the nodes and
334 constructors and at the paragraph COPING WITH DATA OBJECTS at the
335 end of this documentation.
337 The comfortable interface contains the following routines further explained
340 ir_node *new_immBlock (void);
341 ir_node *new_Start (void);
342 ir_node *new_End (void);
343 ir_node *new_Jmp (void);
344 ir_node *new_Cond (ir_node *c);
345 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
346 ir_node *new_Raise (ir_node *store, ir_node *obj);
347 ir_node *new_Const (ir_mode *mode, tarval *con);
348 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
349 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
350 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity,
351 ir_node **in, entity *ent);
352 ir_node *new_Call (ir_node *store, ir_node *callee, int arity,
353 ir_node **in, type_method *type);
354 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
355 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
356 ir_node *new_Minus (ir_node *op, ir_mode *mode);
357 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
358 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
359 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
360 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
361 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
362 ir_node *new_Abs (ir_node *op, ir_mode *mode);
363 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
364 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
365 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
366 ir_node *new_Not (ir_node *op, ir_mode *mode);
367 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
368 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
369 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
370 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
371 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
372 ir_node *new_Conv (ir_node *op, ir_mode *mode);
373 ir_node *new_Load (ir_node *store, ir_node *addr);
374 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
375 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
377 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
379 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
381 void add_in_edge (ir_node *block, ir_node *jmp);
382 void mature_block (ir_node *block);
383 void switch_block (ir_node *target);
384 ir_node *get_value (int pos, ir_mode *mode);
385 void set_value (int pos, ir_node *value);
386 ir_node *get_store (void);
387 void set_store (ir_node *store);
390 IR_NODES AND CONSTRUCTORS FOR IR_NODES
391 =======================================
393 All ir_nodes are defined by a common data structure. They are distinguished
394 by their opcode and differ in the number of their attributes.
396 The constructor for the block node sets current_block to itself.
397 Const nodes are always added to the start block.
398 All other constructors add the created node to the current_block.
399 swich_block(block) allows to set the current block to block.
401 Watch for my inconsistent use of input and predecessor (dataflow view)
402 and `the node points to' (implementation view).
404 The following description of the nodes lists four properties them if these
406 - the parameters to the constructor
407 - the inputs of the Firm node
408 - the outputs of the Firm node
409 - attributes to the node
414 ir_node *new_immBlock (void)
415 ----------------------------
417 Creates a new block. Sets current_block to itself. When a new block is
418 created it cannot be known how many predecessors this block will have in the
419 control flow graph. Therefore the list of inputs can not be fixed at
420 creation. Predecessors can be added with add_in_edge (block, control flow
421 operation). With every added predecessor the number of inputs to Phi nodes
424 The block can be completed by mature_block(block) if all predecessors are
425 known. If several blocks are built at once, mature_block can only be called
426 after set_value has been called for all values that are life at the end
427 of the block. This is necessary so that Phi nodes created by mature_block
428 get the right predecessors in case of cyclic dependencies. If all set_values
429 of this block are called after maturing it and before calling get_value
430 in some block that is control flow dependent on this block, the construction
433 Example for faulty ir construction: (draw the graph on a paper and you'll
436 block_before_loop = new_block();
438 mature_block(block_before_loop);
439 before2header = new_Jmp;
441 loop_header = new_block ();
442 header2body - new_Jmp();
444 loop_body = new_block ();
445 body2header = new_Jmp();
447 add_in_edge(loop_header, before2header);
448 add_in_edge(loop_header, body2header);
449 add_in_edge(loop_body, header2body);
451 mature_block(loop_header);
452 mature_block(loop_body);
454 get_value(loop_body, x); // gets the Phi in loop_header
455 set_value(loop_header, x); // sets the value the above get_value should
458 Mature_block also fixes the number of inputs to the Phi nodes. Mature_block
459 should be called as early as possible, as afterwards the generation of Phi
460 nodes is more efficient.
463 There is an input for each control flow predecessor of the block.
464 The input points to an instruction producing an output of type X.
465 Possible predecessors: Start, Jmp, Cond, Raise or Return or any node
466 possibly causing an exception. (Often the real predecessors are Projs.)
468 Mode BB (R), all nodes belonging to this block should consume this output.
469 As they are strict (except Block and Phi node) it is a necessary condition
470 that the block node executed before any other node in this block executes.
472 block.matured Indicates whether the block is mature.
474 This attribute contains all local values valid in this
475 block. This is needed to build the Phi nodes and removed
476 if the graph is complete. This field is used by the
477 internal construction algorithm and should not be accessed
481 ir_node *new_Block (int arity, ir_node **in)
482 --------------------------------------------
484 Creates a new Block with the given list of predecessors. This block
488 CONTROL FLOW OPERATIONS
489 -----------------------
491 In each block there must be exactly one of the control flow
492 operations Start, End, Jmp, Cond, Return or Raise. The output of a
493 control flow operation points to the block to be executed next.
495 ir_node *new_Start (void)
496 -------------------------
498 Creates a start node. Not actually needed public. There is only one such
499 node in each procedure which is automatically created by new_ir_graph.
502 No inputs except the block it belogns to.
504 A tuple of 4 (5, 6) distinct values. These are labeled by the following
505 projection numbers (pns_number):
507 mode X, points to the first block to be executed.
509 mode M, the global store
510 * pns_frame_base mode P, a pointer to the base of the procedures
512 * pns_globals mode P, a pointer to the part of the memory containing
514 * pns_args mode T, a tuple containing all arguments of the procedure.
517 ir_node *new_End (void)
518 -----------------------
520 Creates an end node. Not actually needed public. There is only one such
521 node in each procedure which is automatically created by new_ir_graph.
524 No inputs except the block it belongs to.
528 ir_node *new_Jmp (void)
529 -----------------------
534 The block the node belongs to
536 Control flow to the next block.
538 ir_node *new_Cond (ir_node *c)
539 ------------------------------
541 Creates a Cond node. There are two versions of this node.
547 A tuple of two control flows. The first is taken if the input is
548 false, the second if it is true.
552 A value of mode I_u. (i)
554 A tuple of n control flows. If the Cond's input is i, control
555 flow will procede along output i. If the input is >= n control
556 flow proceeds along output n.
558 ir_node *new_Return (in_node *store, int arity, ir_node **in)
559 -------------------------------------------------------------
561 The return node has as inputs the results of the procedure. It
562 passes the control flow to the end_block.
568 Control flow to the end block.
570 ir_node *new_Raise (ir_node *store, ir_node *obj)
571 -------------------------------------------------
573 Raises an exception. Unconditional change of control flow. Writes
574 an explicit Except variable to memory to pass it to the exception
575 handler. See TechReport 1999-14, chapter Exceptions.
579 A pointer to the Except variable.
581 A tuple of control flow and the changed memory state. The control flow
582 points to the exception handler if it is definied in this procedure,
583 else it points to the end_block.
589 ir_node *new_Const (ir_mode *mode, tarval *con)
590 -----------------------------------------------
592 Creates a constant in the constant table and adds a Const node
593 returning this value to the start block.
596 *mode The mode of the constant.
597 *con Points to an entry in the constant table.
598 This pointer is added to the attributes of
599 the node (self->attr.con)
601 No inputs except the block it belogns to.
605 attr.con A tarval* pointer to the proper entry in the constant
608 ir_node *new_SymConst (type *type, symconst_kind kind)
609 ------------------------------------------------------------
611 There are three kinds of symbolic constants:
612 type_tag The symbolic constant represents a type tag.
613 size The symbolic constant represents the size of a class.
614 link_info Information for the linker, e.g. the name of a global
618 kind The kind of the symbolic constant: type_tag, size or link_info.
619 *type Points to the type the tag stands for or to the type
620 whose size is represented by the constant.
623 No inputs except the block it belogns to.
625 An unsigned integer (I_u) or a pointer (P).
628 attr.i.num The symconst_kind, i.e. one of
632 If the attr.i.num is type_tag or size, the node contains an attribute
633 attr.i.*type A pointer to a type_class.
634 if it is linkage_ptr_info it contains
635 attr.i.*ptrinfo A ident holding information for the linker.
640 ir_node *new_simpleSel (ir_node *store, ir_node *frame, entity *sel)
641 --------------------------------------------------------------------
644 Selects an entity from a compound type. This entity can be a field or
648 *store The memory in which the object the entity should be selected
650 *frame The pointer to the object.
651 *sel The entity to select.
654 The memory containing the object.
655 A pointer to the object.
658 A pointer to the selected entity.
660 attr.sel Pointer to the entity
663 ir_node *new_Sel (ir_node *store, ir_node *frame, int arity, ir_node **in,
664 --------------------------------------------------------------------------
668 Selects a field from an array type. The entity has as owner the array, as
669 type the arrays element type. The indexes to access an array element are
673 *store The memory in which the object the entity should be selected from
675 *frame The pointer to the object.
676 *arity number of array indexes.
677 *in array with index inputs to the node.
678 *sel The entity to select.
681 The memory containing the object.
682 A pointer to the object.
683 As much unsigned integer as there are array expressions.
685 A pointer to the selected entity.
687 attr.sel Pointer to the entity
689 The constructors new_Sel and new_simpleSel generate the same ir nodes.
690 simpleSel just sets the arity of the index inputs to zero.
693 ARITHMETIC OPERATIONS
694 ---------------------
696 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
697 ----------------------------------------------------------------------------
701 Creates a procedure call.
704 *store The actual store.
705 *callee A pointer to the called procedure.
706 arity The number of procedure parameters.
707 **in An array with the pointers to the parameters.
708 The constructor copies this array.
709 *type Type information of the procedure called.
712 The store, the callee and the parameters.
714 A tuple containing the eventually changed store and the procedure
717 attr.call Contains the type information for the procedure.
719 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode)
720 ------------------------------------------------------------
724 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode)
725 ------------------------------------------------------------
729 ir_node *new_Minus (ir_node *op, ir_mode *mode)
730 -----------------------------------------------
732 This constructor is for unary Minus operations on floating point
733 values. Such a Minus can trap if it is implemented as a Sub from
734 zero due to rounding errors.
736 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode)
737 ------------------------------------------------------------
741 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2)
742 --------------------------------------------------------------
744 Quot performs exact division of floating point numbers. It's mode
745 is Tuple, the mode of the result must be annotated to the Proj
746 that extracts the result of the arithmetic operations.
749 The store needed to model exceptions and the two operands.
751 A tuple contaning a memory and a execution for modeling exceptions
752 and the result of the arithmetic operation.
754 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2)
755 ----------------------------------------------------------------
757 Performs Div and Mod on interger values.
760 A tuple contaning a memory and a execution for modeling exceptions
761 and the two result of the arithmetic operations.
763 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2)
764 -------------------------------------------------------------
768 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2)
769 -------------------------------------------------------------
773 ir_node *new_Abs (ir_node *op, ir_mode *mode)
774 ---------------------------------------------
778 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode)
779 ------------------------------------------------------------
783 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode)
784 -----------------------------------------------------------
788 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode)
789 ------------------------------------------------------------
793 ir_node *new_Not (ir_node *op, ir_mode *mode)
794 ---------------------------------------------
796 This node constructs a constant where all bits are set to one
797 and a Eor of this constant and the operator. This simulates a
800 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode)
801 ---------------------------------------------------------
805 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode)
806 ---------------------------------------------------------
808 Logic shift right, i.e., zero extended.
811 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode)
812 ----------------------------------------------------------
814 Arithmetic shift right, i.e., sign extended.
816 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode)
817 ---------------------------------------------------------
819 Rotates the operand to the (right??) by k bits.
821 ir_node *new_Conv (ir_node *op, ir_mode *mode)
822 ---------------------------------------------
824 Mode conversion. For allowed conversions see UKA Tech Report
827 ir_node *new_Cmp (ir_node *op1, ir_node *op2)
828 ---------------------------------------------
831 The two values to be compared.
833 A 16-tuple containing the results of the 16 different comparisons.
834 The following is a list giving the comparisons and a projection
835 number (pnc_number) to use in Proj nodes to extract the proper result.
843 Leg less, equal or greater = ordered
845 Ue unordered or equal
847 Ule unordered, less or equal
848 Ug unordered or greater
849 Uge unordered, greater or equal
850 Ne unordered, less or greater = not equal
858 In general, Phi nodes are automaitcally inserted. In some cases, if
859 all predecessors of a block are known, an explicit Phi node constructor
860 is needed. E.g., to construct a FIRM graph for a statement as
863 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode)
864 ---------------------------------------------------------
866 Creates a Phi node. The in's order has to correspond to the order
867 of in's of current_block. This is not checked by the library!
870 arity number of predecessors
871 **in array with predecessors
872 *mode The mode of it's inputs and output.
874 A Phi node has as many inputs as the block it belongs to.
875 Each input points to a definition of the same value on a
876 different path in the control flow.
878 The definition valid in this block.
881 OPERATIONS TO MANAGE MEMORY EXPLICITLY
882 --------------------------------------
884 ir_node *new_Load (ir_node *store, ir_node *addr)
885 ----------------------------------------------------------------
887 The Load operation reads a value from memory.
890 *store The current memory.
891 *addr A pointer to the variable to be read in this memory.
892 *mode The mode of the loaded value.
895 The memory and a pointer to a variable in this memory.
897 A tuple of the memory, a control flow to be taken in case of
898 an exception and the loaded value.
900 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val)
901 ----------------------------------------------------------------
903 The Store operation writes a value to a variable in memory.
906 The memory, a pointer to a variable in this memory and the value
907 to write to this variable.
909 A tuple of the changed memory and a control flow to be taken in
910 case of an exception.
912 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
913 --------------------------------------------------------------------
917 The Alloc node allocates a new variable. It can be specified whether the
918 variable should be allocated to the stack or to the heap.
921 *store The memory which shall contain the new variable.
922 ** *size The number of bytes to allocate. Old. **
923 *size We decided that the size easily can be derived from the type.
924 This field is for allocating arrays, i.e., it gives the multiple
925 of the size of alloc_type to allocate memory for.
926 *alloc_type The type of the allocated variable.
927 where Where to allocate the variable, either heap_alloc or stack_alloc.
930 A memory and an unsigned integer.
932 A tuple of the changed memory, a control flow to be taken in
933 case of an exception and the pointer to the new variable.
935 a.where Indicates where the variable is allocated.
936 a.*type A pointer to the class the allocated data object
939 ir_node *new_Free (ir_node *store, ir_node *ptr, type *free_type)
940 ------------------------------------------------------------------
942 The Free node frees memory of the given variable.
945 *store The memory which shall contain the new variable.
946 *ptr The pointer to the object to free.
947 *size The number of objects of type free_type to free in a sequence.
948 *free_type The type of the freed variable.
951 A memory, a pointer and an unsigned integer.
955 f.*type A pointer to the type information of the freed data object.
959 ir_node *new_Sync (int arity, ir_node **in)
960 -------------------------------------------
962 The Sync operation unifies several partial memory blocks. These blocks
963 have to be pairwise disjunct or the values in common locations have to
964 be identical. This operation allows to specify all operations that eventually
965 need several partial memory blocks as input with a single entrance by
966 unifying the memories with a preceding Sync operation.
969 arity The number of memories to syncronize.
970 **in An array of pointers to nodes that produce an output of
981 ir_node *new_Bad (void)
982 -----------------------
984 Returns the unique Bad node current_ir_graph->bad.
985 This node is used to express results of dead code elimination.
987 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj)
988 ----------------------------------------------------------
990 Selects one entry of a tuple. This is a hidden `fat edge'.
993 *arg A node producing a tuple.
994 *mode The mode of the value to project.
995 proj The position of the value in the tuple.
1001 ir_node *new_Tuple (int arity, ir_node **in)
1002 --------------------------------------------
1004 Builds a Tuple from single values. This is needed to implement
1005 optimizations that remove a node that produced a tuple. The node can be
1006 replaced by the Tuple operation so that the following Proj nodes have not to
1007 be changed. (They are hard to find due to the implementation with pointers
1008 in only one direction.) The Tuple node is smaller than any other
1009 node, so that a node can be changed into a Tuple by just changing it's
1010 opcode and giving it a new in array.
1013 arity The number of tuple elements.
1014 **in An array containing pointers to the nodes producing the
1017 ir_node *new_Id (ir_node *val, ir_mode *mode)
1018 ---------------------------------------------
1020 The single output of the Id operation is it's input. Also needed
1024 COPING WITH DATA OBJECTS
1025 ========================
1027 Two kinds of data objects have to be distinguished for generating
1028 FIRM. First there are local variables other than arrays that are
1029 known to be alias free. Second there are all other data objects.
1030 For the first a common SSA representation is built, the second
1031 are modeled by saving them to memory. The memory is treated as
1032 a single local variable, the alias problem is hidden in the
1033 content of this variable.
1035 All values known in a Block are listed in the block's attribute,
1036 block.**graph_arr which is used to automatically insert Phi nodes.
1037 The following two funcions can be used to add a newly computed value
1038 to the array, or to get the producer of a value, i.e., the current
1041 inline void set_value (int pos, ir_node *value)
1042 -----------------------------------------------
1044 Has to be called for every assignment to a local variable. It
1045 adds the value to the array of used values at position pos. Pos
1046 has to be a unique identifier for an entry in the procedure's
1047 definition table. It can be used to access the value again.
1049 ir_node *get_value (int pos, ir_mode *mode)
1050 -------------------------------------------
1052 Returns the node defining the value referred to by pos. If the
1053 value is not defined in this block a Phi node is generated and
1054 all definitions reaching this Phi node are collected. It can
1055 happen that the algorithm allocates an unnecessary Phi node,
1056 e.g. if there is only one definition of this value, but this
1057 definition reaches the currend block on several different
1058 paths. This Phi node will be eliminated if optimizations are
1059 turned on right after it's creation.
1062 There are two special routines for the global store:
1064 inline void set_store (ir_node *store)
1065 --------------------------------------
1067 Adds the store to the array of known values at a reserved
1070 inline ir_node *get_store (void)
1071 --------------------------------
1073 Returns the node defining the actual store.
1081 # include "irgraph.h"
1082 # include "irnode.h"
1083 # include "irmode.h"
1084 # include "entity.h"
1089 #if USE_EXPICIT_PHI_IN_STACK
1090 /* A stack needed for the automatic Phi node construction in constructor
1092 typedef struct Phi_in_stack Phi_in_stack;
1095 /***************************************************************************/
1096 /* The raw interface */
1098 ir_node *new_r_Block (ir_graph *irg, int arity, ir_node **in);
1099 ir_node *new_r_Start (ir_graph *irg, ir_node *block);
1100 ir_node *new_r_End (ir_graph *irg, ir_node *block);
1101 ir_node *new_r_Jmp (ir_graph *irg, ir_node *block);
1102 ir_node *new_r_Cond (ir_graph *irg, ir_node *block, ir_node *c);
1103 ir_node *new_r_Return (ir_graph *irg, ir_node *block,
1104 ir_node *store, int arity, ir_node **in);
1105 ir_node *new_r_Raise (ir_graph *irg, ir_node *block,
1106 ir_node *store, ir_node *obj);
1107 ir_node *new_r_Const (ir_graph *irg, ir_node *block,
1108 ir_mode *mode, tarval *con);
1109 ir_node *new_r_SymConst (ir_graph *irg, ir_node *block,
1110 type_or_id *value, symconst_kind symkind);
1111 ir_node *new_r_Sel (ir_graph *irg, ir_node *block, ir_node *store,
1112 ir_node *objptr, int n_index, ir_node **index,
1114 ir_node *new_r_Call (ir_graph *irg, ir_node *block, ir_node *store,
1115 ir_node *callee, int arity, ir_node **in,
1117 ir_node *new_r_Add (ir_graph *irg, ir_node *block,
1118 ir_node *op1, ir_node *op2, ir_mode *mode);
1119 ir_node *new_r_Sub (ir_graph *irg, ir_node *block,
1120 ir_node *op1, ir_node *op2, ir_mode *mode);
1121 ir_node *new_r_Minus (ir_graph *irg, ir_node *block,
1122 ir_node *op, ir_mode *mode);
1123 ir_node *new_r_Mul (ir_graph *irg, ir_node *block,
1124 ir_node *op1, ir_node *op2, ir_mode *mode);
1125 ir_node *new_r_Quot (ir_graph *irg, ir_node *block,
1126 ir_node *memop, ir_node *op1, ir_node *op2);
1127 ir_node *new_r_DivMod (ir_graph *irg, ir_node *block,
1128 ir_node *memop, ir_node *op1, ir_node *op2);
1129 ir_node *new_r_Div (ir_graph *irg, ir_node *block,
1130 ir_node *memop, ir_node *op1, ir_node *op2);
1131 ir_node *new_r_Mod (ir_graph *irg, ir_node *block,
1132 ir_node *memop, ir_node *op1, ir_node *op2);
1133 ir_node *new_r_Abs (ir_graph *irg, ir_node *block,
1134 ir_node *op, ir_mode *mode);
1135 ir_node *new_r_And (ir_graph *irg, ir_node *block,
1136 ir_node *op1, ir_node *op2, ir_mode *mode);
1137 ir_node *new_r_Or (ir_graph *irg, ir_node *block,
1138 ir_node *op1, ir_node *op2, ir_mode *mode);
1139 ir_node *new_r_Eor (ir_graph *irg, ir_node *block,
1140 ir_node *op1, ir_node *op2, ir_mode *mode);
1141 ir_node *new_r_Not (ir_graph *irg, ir_node *block,
1142 ir_node *op, ir_mode *mode);
1143 ir_node *new_r_Cmp (ir_graph *irg, ir_node *block,
1144 ir_node *op1, ir_node *op2);
1145 ir_node *new_r_Shl (ir_graph *irg, ir_node *block,
1146 ir_node *op, ir_node *k, ir_mode *mode);
1147 ir_node *new_r_Shr (ir_graph *irg, ir_node *block,
1148 ir_node *op, ir_node *k, ir_mode *mode);
1149 ir_node *new_r_Shrs (ir_graph *irg, ir_node *block,
1150 ir_node *op, ir_node *k, ir_mode *mode);
1151 ir_node *new_r_Rot (ir_graph *irg, ir_node *block,
1152 ir_node *op, ir_node *k, ir_mode *mode);
1153 ir_node *new_r_Conv (ir_graph *irg, ir_node *block,
1154 ir_node *op, ir_mode *mode);
1155 ir_node *new_r_Phi (ir_graph *irg, ir_node *block, int arity,
1156 ir_node **in, ir_mode *mode);
1157 ir_node *new_r_Load (ir_graph *irg, ir_node *block,
1158 ir_node *store, ir_node *adr);
1159 ir_node *new_r_Store (ir_graph *irg, ir_node *block,
1160 ir_node *store, ir_node *adr, ir_node *val);
1161 ir_node *new_r_Alloc (ir_graph *irg, ir_node *block, ir_node *store,
1162 ir_node *size, type *alloc_type, where_alloc where);
1163 ir_node *new_r_Free (ir_graph *irg, ir_node *block, ir_node *store,
1164 ir_node *ptr, ir_node *size, type *free_type);
1165 ir_node *new_r_Sync (ir_graph *irg, ir_node *block, int arity, ir_node **in);
1166 ir_node *new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg,
1167 ir_mode *mode, long proj);
1168 ir_node *new_r_Tuple (ir_graph *irg, ir_node *block,
1169 int arity, ir_node **in);
1170 ir_node *new_r_Id (ir_graph *irg, ir_node *block,
1171 ir_node *val, ir_mode *mode);
1172 ir_node *new_r_Bad (ir_node *block);
1175 /*************************************************************************/
1176 /* The block oriented interface */
1178 /* Sets the current block in which the following constructors place the
1179 nodes they construct. */
1180 void switch_block (ir_node *target);
1182 /* Chris: please rename the Block constructor:
1183 new_Block to new_immBlock
1184 and add a new one so dass das dann so aussieht:
1185 passe die Beispeilprogramme an! */
1187 ir_node *new_Block(int arity, ir_node **in); /* creates mature Block */
1189 ir_node *new_Block (void);
1191 ir_node *new_Start (void);
1192 ir_node *new_End (void);
1193 ir_node *new_Jmp (void);
1194 ir_node *new_Cond (ir_node *c);
1195 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
1196 ir_node *new_Raise (ir_node *store, ir_node *obj);
1197 ir_node *new_Const (ir_mode *mode, tarval *con);
1198 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
1199 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
1200 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity, ir_node **in,
1202 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
1204 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
1205 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
1206 ir_node *new_Minus (ir_node *op, ir_mode *mode);
1207 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
1208 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
1209 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
1210 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
1211 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
1212 ir_node *new_Abs (ir_node *op, ir_mode *mode);
1213 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
1214 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
1215 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
1216 ir_node *new_Not (ir_node *op, ir_mode *mode);
1217 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
1218 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
1219 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
1220 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
1221 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
1222 ir_node *new_Conv (ir_node *op, ir_mode *mode);
1223 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode);
1224 ir_node *new_Load (ir_node *store, ir_node *addr);
1225 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
1226 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
1228 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
1230 ir_node *new_Sync (int arity, ir_node **in);
1231 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
1232 ir_node *new_Tuple (int arity, ir_node **in);
1233 ir_node *new_Id (ir_node *val, ir_mode *mode);
1234 ir_node *new_Bad (void);
1236 /***********************************************************************/
1237 /* The comfortable interface. */
1238 /* Supports automatic Phi node construction. */
1239 /* All routines of the block oriented interface except new_Block are */
1242 /** Block construction **/
1243 /* immature Block without predecessors */
1244 ir_node *new_immBlock (void);
1246 /* Add a control flow edge to an immature block. */
1247 void add_in_edge (ir_node *immblock, ir_node *jmp);
1249 /* fixes the number of predecessors of a block. */
1250 void mature_block (ir_node *block);
1252 /** Parameter administration **/
1253 /* Read a value from the array with the local variables. Use this
1254 function to obtain the last definition of the value associated with
1256 ir_node *get_value (int pos, ir_mode *mode);
1258 /* Write a value in the array with the local variables. Use this function
1259 to remember a new definition of the value associated with pos. */
1260 void set_value (int pos, ir_node *value);
1263 Use this function to get the most recent version of the store (type M).
1264 Internally it does the same as get_value. */
1265 ir_node *get_store (void);
1267 /* Write a store. */
1268 void set_store (ir_node *store);
1271 /* This function is for internal use only. It is visible as it is needed
1272 in irgraph.c to create the stack that is needed for automatic Phi
1274 #if USE_EXPICIT_PHI_IN_STACK
1275 Phi_in_stack *new_Phi_in_stack();
1278 /**************************************************************************/
1279 /* initialize ir construction */
1280 void init_cons (void);
1283 # endif /* _IRCONS_H_ */