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.
104 visited A int used as flag to traverse the ir_graph.
106 block_visited A int used as a flag to traverse block nodes in the graph.
111 There are three kinds of nodes known to the ir: entities,
114 + ir_nodes are the actual nodes of the FIRM intermediate representation.
115 They represent operations on the data of the program and control flow
118 + entity ==> implemented in entity.h
119 Refers to a single entity of the compiled program, e.g. a field of a
120 class or a method. If a method or variable can not be assigned to
121 a method or class or the like, it is a global object.
123 + types ==> implemented in type.h
124 With types type information is represented. There are several type
127 Implementation of the FIRM operations: ir_node
128 ----------------------------------------------
130 Ir_nodes represent operations on the data of the program and control flow
131 operations. Examples of ir_nodes: Add, Jmp, Cmp
133 FIRM is a dataflow graph. A dataflow graph is a directed graph,
134 so that every node has incoming and outgoing edges. A node is
135 executable if every input at it's incoming edges is available.
136 Execution of the dataflow graph is started at the Start node which
137 has no incoming edges and ends when the End node executes, even if
138 there are still executable or not executed nodes. (Is this true,
139 or must all executable nodes be executed?) (There are exceptions
140 to the dataflow paradigma that all inputs have to be available
141 before a node can execute: Phi, Block. See UKA Techreport
144 The implementation of FIRM differs from the view as a dataflow
145 graph. To allow fast traversion of the graph edges are
146 implemented as C-pointers. Inputs to nodes are not ambiguous, the
147 results can be used by several other nodes. Each input can be
148 implemented as a single pointer to a predecessor node, outputs
149 need to be lists of pointers to successors. Therefore a node
150 contains pointers to it's predecessor so that the implementation is a
151 dataflow graph with reversed edges. It has to be traversed bottom
154 All nodes of the ir have the same basic structure. They are
155 distinguished by a field containing the opcode.
157 The fields of an ir_node:
159 kind A firm_kind tag containing k_ir_node. This is useful for
160 dynamically checking the type of a node.
162 *op This ir_op gives the opcode as a tag and a string
163 and the number of attributes of an ir_node. There is
164 one statically allocated struct ir_op for each opcode.
166 *mode The ir_mode of the operation represented by this firm
167 node. The mode of the operation is the mode of it's
168 result. A Firm mode is a datatype as known to the target,
169 not a type of the source language.
171 visit A flag for traversing the ir.
173 **in An array with pointers to the node's predecessors.
175 *link A pointer to an ir_node. With this pointer all Phi nodes
176 are attached to a Block, i.e., a Block points to it's
177 first Phi node, this node points to the second Phi node
178 in the Block and so fourth. Used in mature_block
179 to find all Phi nodes to be matured. It's also used to
180 annotate a node with a better, optimized version of it.
182 attr An attr struct containing the attributes of the nodes. The
183 attributes depend on the opcode of the node. The number
184 of these attributes is given in op.
188 Not yet documented. See irop.h.
192 Not yet documented. See irmode.h.
197 current_ir_graph Points to the current ir_graph. All constructors for
198 nodes add nodes to this graph.
200 ir_visited An int used as flag to traverse the ir_graph.
202 block_visited An int used as a flag to traverse block nodes in the
205 Others not yet documented.
209 CONSTRUCTOR FOR IR_GRAPH
210 ========================
212 ir_graph *new_ir_graph (entity *ent, int params);
213 -------------------------------------------------
215 This constructor generates the basic infrastructure needed to
216 represent a procedure in FIRM.
218 The parameters of new_ir_graph are:
220 *ent A pointer to an entity representing the procedure.
222 params An integer giving the number of local variables in the
225 It allocates an ir_graph and sets current_ir_graph to point to this
226 graph. Further it allocates the following nodes needed for every
229 * The start block containing a start node and Proj nodes for it's
230 five results (X, M, P, P, T).
231 * The end block containing an end node. This block is not matured
232 after executing new_ir_graph as predecessors need to be added to it.
233 (Maturing a block means fixing it's number of predecessors.)
234 * The current block, which is empty and also not matured.
236 Further it enters the global store into the datastructure of the start
237 block that contanis all valid values in this block (set_store()). This
238 datastructure is used to build the Phi nodes and removed after completion
240 There is no path from end to start in the graph after calling ir_graph.
243 PROCEDURE TO CONSTRUCT AN IR GRAPH
244 ==================================
246 This library supplies several interfaces to construct a FIRM graph for
248 * A "comfortable" interface generating SSA automatically. Automatically
249 computed predecessors of nodes need not be specified in the constructors.
250 (new_<Node> constructurs and a set of additional routines.)
251 * A less comfortable interface where all predecessors except the block
252 an operation belongs to need to be specified. SSA must be constructed
253 by hand. (new_<Node> constructors and switch_block()). This interface
254 is called "block oriented". It automatically calles the local optimizations
256 * An even less comfortable interface where the block needs to be specified
257 explicitly. This is called the "raw" interface. (new_r_<Node>
258 constructors). These nodes are not optimized.
260 To use the functionality of the comfortable interface correctly the Front
261 End needs to follow certain protocols. This is explained in the following.
262 To build a correct IR with the other interfaces study the semantics of
263 the firm node (See tech-reprot UKA 1999-44). For the construction of
264 types and entities see the documentation in those modules.
266 First the Frontend needs to decide which variables and values used in
267 a procedure can be represented by dataflow edges. These are variables
268 that need not be saved to memory as they cause no side effects visible
269 out of the procedure. In general these are all compiler generated
270 variables and simple local variables of the procedure as integers,
271 reals and pointers. The frontend has to count and number these variables.
273 First an ir_graph needs to be constructed with new_ir_graph. The
274 constructor gets the number of local variables. The graph is hold in the
277 Now the construction of the procedure can start. Several basic blocks can
278 be constructed in parallel, but the code within each block needs to
279 be constructed (almost) in program order.
281 A global variable holds the current basic block. All (non block) nodes
282 generated are added to this block. The current block can be set with
283 switch_block(block). If several blocks are constructed in parallel block
284 switches need to be performed constantly.
286 To generate a Block node (with the comfortable interface) it's predecessor
287 control flow nodes need not be known. In case of cyclic control flow these
288 can not be known when the block is constructed. With add_in_edge(block,
289 cfnode) predecessors can be added to the block. If all predecessors are
290 added to the block mature_block(b) needs to be called. Calling mature_block
291 early improves the efficiency of the Phi node construction algorithm.
292 But if several blocks are constructed at once, mature_block must only
293 be called after performing all set_values and set_stores in the block!
294 (See documentation of new_immBlock constructor.)
296 The constructors of arithmetic nodes require that their predecessors
297 are mentioned. Sometimes these are available in the Frontend as the
298 predecessors have just been generated by the frontend. If they are local
299 values the predecessors can be obtained from the library with a call to
300 get_value(local_val_nr). (local_val_nr needs to be administered by
301 the Frontend.) A call to get_value triggers the generation of Phi nodes.
302 If an arithmetic operation produces a local value this value needs to be
303 passed to the library by set_value(node, local_val_nr).
304 In straight line code these two operations just remember and return the
305 pointer to nodes producing the value. If the value passes block boundaries
306 Phi nodes can be inserted.
307 Similar routines exist to manage the Memory operands: set_store and
310 Several nodes produce more than one result. An example is the Div node.
311 Such nodes return tuples of values. From these individual values can be
312 extracted by proj nodes.
314 The following example illustrates the construction of a simple basic block
315 with two predecessors stored in variables cf_pred1 and cf_pred2, containing
318 and finally jumping to an other block. The variable a got the local_val_nr
321 ir_node *this_block, *cf_pred1, *cf_pred2, *a_val, *mem, *div, *res, *cf_op;
323 this_block = new_immBlock();
324 add_in_edge(this_block, cf_pred1);
325 add_in_edge(this_block, cf_pred2);
326 mature_block(this_block);
327 a_val = get_value(17, mode_I);
329 div = new_Div(mem, a_val, a_val);
330 mem = new_Proj(div, mode_M, 0); * for the numbers for Proj see docu *
331 res = new_Proj(div, mode_I, 2);
336 For further information look at the documentation of the nodes and
337 constructors and at the paragraph COPING WITH DATA OBJECTS at the
338 end of this documentation.
340 The comfortable interface contains the following routines further explained
343 ir_node *new_immBlock (void);
344 ir_node *new_Start (void);
345 ir_node *new_End (void);
346 ir_node *new_Jmp (void);
347 ir_node *new_Cond (ir_node *c);
348 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
349 ir_node *new_Raise (ir_node *store, ir_node *obj);
350 ir_node *new_Const (ir_mode *mode, tarval *con);
351 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
352 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
353 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity,
354 ir_node **in, entity *ent);
355 ir_node *new_Call (ir_node *store, ir_node *callee, int arity,
356 ir_node **in, type_method *type);
357 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
358 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
359 ir_node *new_Minus (ir_node *op, ir_mode *mode);
360 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
361 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
362 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
363 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
364 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
365 ir_node *new_Abs (ir_node *op, ir_mode *mode);
366 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
367 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
368 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
369 ir_node *new_Not (ir_node *op, ir_mode *mode);
370 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
371 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
372 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
373 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
374 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
375 ir_node *new_Conv (ir_node *op, ir_mode *mode);
376 ir_node *new_Load (ir_node *store, ir_node *addr);
377 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
378 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
380 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
382 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
384 void add_in_edge (ir_node *block, ir_node *jmp);
385 void mature_block (ir_node *block);
386 void switch_block (ir_node *target);
387 ir_node *get_value (int pos, ir_mode *mode);
388 void set_value (int pos, ir_node *value);
389 ir_node *get_store (void);
390 void set_store (ir_node *store);
393 IR_NODES AND CONSTRUCTORS FOR IR_NODES
394 =======================================
396 All ir_nodes are defined by a common data structure. They are distinguished
397 by their opcode and differ in the number of their attributes.
399 The constructor for the block node sets current_block to itself.
400 Const nodes are always added to the start block.
401 All other constructors add the created node to the current_block.
402 swich_block(block) allows to set the current block to block.
404 Watch for my inconsistent use of input and predecessor (dataflow view)
405 and `the node points to' (implementation view).
407 The following description of the nodes lists four properties them if these
409 - the parameters to the constructor
410 - the inputs of the Firm node
411 - the outputs of the Firm node
412 - attributes to the node
417 ir_node *new_immBlock (void)
418 ----------------------------
420 Creates a new block. Sets current_block to itself. When a new block is
421 created it cannot be known how many predecessors this block will have in the
422 control flow graph. Therefore the list of inputs can not be fixed at
423 creation. Predecessors can be added with add_in_edge (block, control flow
424 operation). With every added predecessor the number of inputs to Phi nodes
427 The block can be completed by mature_block(block) if all predecessors are
428 known. If several blocks are built at once, mature_block can only be called
429 after set_value has been called for all values that are life at the end
430 of the block. This is necessary so that Phi nodes created by mature_block
431 get the right predecessors in case of cyclic dependencies. If all set_values
432 of this block are called after maturing it and before calling get_value
433 in some block that is control flow dependent on this block, the construction
436 Example for faulty ir construction: (draw the graph on a paper and you'll
439 block_before_loop = new_block();
441 mature_block(block_before_loop);
442 before2header = new_Jmp;
444 loop_header = new_block ();
445 header2body - new_Jmp();
447 loop_body = new_block ();
448 body2header = new_Jmp();
450 add_in_edge(loop_header, before2header);
451 add_in_edge(loop_header, body2header);
452 add_in_edge(loop_body, header2body);
454 mature_block(loop_header);
455 mature_block(loop_body);
457 get_value(loop_body, x); // gets the Phi in loop_header
458 set_value(loop_header, x); // sets the value the above get_value should
461 Mature_block also fixes the number of inputs to the Phi nodes. Mature_block
462 should be called as early as possible, as afterwards the generation of Phi
463 nodes is more efficient.
466 There is an input for each control flow predecessor of the block.
467 The input points to an instruction producing an output of type X.
468 Possible predecessors: Start, Jmp, Cond, Raise or Return or any node
469 possibly causing an exception. (Often the real predecessors are Projs.)
471 Mode BB (R), all nodes belonging to this block should consume this output.
472 As they are strict (except Block and Phi node) it is a necessary condition
473 that the block node executed before any other node in this block executes.
475 block.matured Indicates whether the block is mature.
477 This attribute contains all local values valid in this
478 block. This is needed to build the Phi nodes and removed
479 if the graph is complete. This field is used by the
480 internal construction algorithm and should not be accessed
484 ir_node *new_Block (int arity, ir_node **in)
485 --------------------------------------------
487 Creates a new Block with the given list of predecessors. This block
491 CONTROL FLOW OPERATIONS
492 -----------------------
494 In each block there must be exactly one of the control flow
495 operations Start, End, Jmp, Cond, Return or Raise. The output of a
496 control flow operation points to the block to be executed next.
498 ir_node *new_Start (void)
499 -------------------------
501 Creates a start node. Not actually needed public. There is only one such
502 node in each procedure which is automatically created by new_ir_graph.
505 No inputs except the block it belogns to.
507 A tuple of 4 (5, 6) distinct values. These are labeled by the following
508 projection numbers (pns_number):
510 mode X, points to the first block to be executed.
512 mode M, the global store
513 * pns_frame_base mode P, a pointer to the base of the procedures
515 * pns_globals mode P, a pointer to the part of the memory containing
517 * pns_args mode T, a tuple containing all arguments of the procedure.
520 ir_node *new_End (void)
521 -----------------------
523 Creates an end node. Not actually needed public. There is only one such
524 node in each procedure which is automatically created by new_ir_graph.
527 No inputs except the block it belongs to.
531 ir_node *new_Jmp (void)
532 -----------------------
537 The block the node belongs to
539 Control flow to the next block.
541 ir_node *new_Cond (ir_node *c)
542 ------------------------------
544 Creates a Cond node. There are two versions of this node.
550 A tuple of two control flows. The first is taken if the input is
551 false, the second if it is true.
555 A value of mode I_u. (i)
557 A tuple of n control flows. If the Cond's input is i, control
558 flow will procede along output i. If the input is >= n control
559 flow proceeds along output n.
561 ir_node *new_Return (in_node *store, int arity, ir_node **in)
562 -------------------------------------------------------------
564 The return node has as inputs the results of the procedure. It
565 passes the control flow to the end_block.
571 Control flow to the end block.
573 ir_node *new_Raise (ir_node *store, ir_node *obj)
574 -------------------------------------------------
576 Raises an exception. Unconditional change of control flow. Writes
577 an explicit Except variable to memory to pass it to the exception
578 handler. See TechReport 1999-14, chapter Exceptions.
582 A pointer to the Except variable.
584 A tuple of control flow and the changed memory state. The control flow
585 points to the exception handler if it is definied in this procedure,
586 else it points to the end_block.
592 ir_node *new_Const (ir_mode *mode, tarval *con)
593 -----------------------------------------------
595 Creates a constant in the constant table and adds a Const node
596 returning this value to the start block.
599 *mode The mode of the constant.
600 *con Points to an entry in the constant table.
601 This pointer is added to the attributes of
602 the node (self->attr.con)
604 No inputs except the block it belogns to.
608 attr.con A tarval* pointer to the proper entry in the constant
611 ir_node *new_SymConst (type *type, symconst_kind kind)
612 ------------------------------------------------------------
614 There are three kinds of symbolic constants:
615 type_tag The symbolic constant represents a type tag.
616 size The symbolic constant represents the size of a class.
617 link_info Information for the linker, e.g. the name of a global
621 kind The kind of the symbolic constant: type_tag, size or link_info.
622 *type_or_id Points to the type the tag stands for or to the type
623 whose size is represented by the constant or to an ident
624 representing the linkage info.
627 No inputs except the block it belogns to.
629 An unsigned integer (I_u) or a pointer (P).
632 attr.i.num The symconst_kind, i.e. one of
636 If the attr.i.num is type_tag or size, the node contains an attribute
637 attr.i.*type A pointer to a type_class.
638 if it is linkage_ptr_info it contains
639 attr.i.*ptrinfo An ident holding information for the linker.
644 ir_node *new_simpleSel (ir_node *store, ir_node *frame, entity *sel)
645 --------------------------------------------------------------------
648 Selects an entity from a compound type. This entity can be a field or
652 *store The memory in which the object the entity should be selected
654 *frame The pointer to the object.
655 *sel The entity to select.
658 The memory containing the object.
659 A pointer to the object.
662 A pointer to the selected entity.
664 attr.sel Pointer to the entity
667 ir_node *new_Sel (ir_node *store, ir_node *frame, int arity, ir_node **in,
668 --------------------------------------------------------------------------
672 Selects a field from an array type. The entity has as owner the array, as
673 type the arrays element type. The indexes to access an array element are
677 *store The memory in which the object the entity should be selected from
679 *frame The pointer to the object.
680 *arity number of array indexes.
681 *in array with index inputs to the node.
682 *sel The entity to select.
685 The memory containing the object.
686 A pointer to the object.
687 As much unsigned integer as there are array expressions.
689 A pointer to the selected entity.
691 attr.sel Pointer to the entity
693 The constructors new_Sel and new_simpleSel generate the same ir nodes.
694 simpleSel just sets the arity of the index inputs to zero.
697 ARITHMETIC OPERATIONS
698 ---------------------
700 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
701 ----------------------------------------------------------------------------
705 Creates a procedure call.
708 *store The actual store.
709 *callee A pointer to the called procedure.
710 arity The number of procedure parameters.
711 **in An array with the pointers to the parameters.
712 The constructor copies this array.
713 *type Type information of the procedure called.
716 The store, the callee and the parameters.
718 A tuple containing the eventually changed store and the procedure
721 attr.call Contains the type information for the procedure.
723 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode)
724 ------------------------------------------------------------
728 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode)
729 ------------------------------------------------------------
733 ir_node *new_Minus (ir_node *op, ir_mode *mode)
734 -----------------------------------------------
736 This constructor is for unary Minus operations on floating point
737 values. Such a Minus can trap if it is implemented as a Sub from
738 zero due to rounding errors.
740 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode)
741 ------------------------------------------------------------
745 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2)
746 --------------------------------------------------------------
748 Quot performs exact division of floating point numbers. It's mode
749 is Tuple, the mode of the result must be annotated to the Proj
750 that extracts the result of the arithmetic operations.
753 The store needed to model exceptions and the two operands.
755 A tuple contaning a memory and a execution for modeling exceptions
756 and the result of the arithmetic operation.
758 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2)
759 ----------------------------------------------------------------
761 Performs Div and Mod on interger values.
764 A tuple contaning a memory and a execution for modeling exceptions
765 and the two result of the arithmetic operations.
767 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2)
768 -------------------------------------------------------------
772 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2)
773 -------------------------------------------------------------
777 ir_node *new_Abs (ir_node *op, ir_mode *mode)
778 ---------------------------------------------
782 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode)
783 ------------------------------------------------------------
787 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode)
788 -----------------------------------------------------------
792 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode)
793 ------------------------------------------------------------
797 ir_node *new_Not (ir_node *op, ir_mode *mode)
798 ---------------------------------------------
800 This node constructs a constant where all bits are set to one
801 and a Eor of this constant and the operator. This simulates a
804 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode)
805 ---------------------------------------------------------
809 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode)
810 ---------------------------------------------------------
812 Logic shift right, i.e., zero extended.
815 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode)
816 ----------------------------------------------------------
818 Arithmetic shift right, i.e., sign extended.
820 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode)
821 ---------------------------------------------------------
823 Rotates the operand to the (right??) by k bits.
825 ir_node *new_Conv (ir_node *op, ir_mode *mode)
826 ---------------------------------------------
828 Mode conversion. For allowed conversions see UKA Tech Report
831 ir_node *new_Cmp (ir_node *op1, ir_node *op2)
832 ---------------------------------------------
835 The two values to be compared.
837 A 16-tuple containing the results of the 16 different comparisons.
838 The following is a list giving the comparisons and a projection
839 number (pnc_number) to use in Proj nodes to extract the proper result.
847 Leg less, equal or greater = ordered
849 Ue unordered or equal
851 Ule unordered, less or equal
852 Ug unordered or greater
853 Uge unordered, greater or equal
854 Ne unordered, less or greater = not equal
862 In general, Phi nodes are automaitcally inserted. In some cases, if
863 all predecessors of a block are known, an explicit Phi node constructor
864 is needed. E.g., to construct a FIRM graph for a statement as
867 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode)
868 ---------------------------------------------------------
870 Creates a Phi node. The in's order has to correspond to the order
871 of in's of current_block. This is not checked by the library!
874 arity number of predecessors
875 **in array with predecessors
876 *mode The mode of it's inputs and output.
878 A Phi node has as many inputs as the block it belongs to.
879 Each input points to a definition of the same value on a
880 different path in the control flow.
882 The definition valid in this block.
885 OPERATIONS TO MANAGE MEMORY EXPLICITLY
886 --------------------------------------
888 ir_node *new_Load (ir_node *store, ir_node *addr)
889 ----------------------------------------------------------------
891 The Load operation reads a value from memory.
894 *store The current memory.
895 *addr A pointer to the variable to be read in this memory.
896 *mode The mode of the loaded value.
899 The memory and a pointer to a variable in this memory.
901 A tuple of the memory, a control flow to be taken in case of
902 an exception and the loaded value.
904 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val)
905 ----------------------------------------------------------------
907 The Store operation writes a value to a variable in memory.
910 The memory, a pointer to a variable in this memory and the value
911 to write to this variable.
913 A tuple of the changed memory and a control flow to be taken in
914 case of an exception.
916 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
917 --------------------------------------------------------------------
921 The Alloc node allocates a new variable. It can be specified whether the
922 variable should be allocated to the stack or to the heap.
925 *store The memory which shall contain the new variable.
926 ** *size The number of bytes to allocate. Old. **
927 *size We decided that the size easily can be derived from the type.
928 This field is for allocating arrays, i.e., it gives the multiple
929 of the size of alloc_type to allocate memory for.
930 *alloc_type The type of the allocated variable.
931 where Where to allocate the variable, either heap_alloc or stack_alloc.
934 A memory and an unsigned integer.
936 A tuple of the changed memory, a control flow to be taken in
937 case of an exception and the pointer to the new variable.
939 a.where Indicates where the variable is allocated.
940 a.*type A pointer to the class the allocated data object
943 ir_node *new_Free (ir_node *store, ir_node *ptr, type *free_type)
944 ------------------------------------------------------------------
946 The Free node frees memory of the given variable.
949 *store The memory which shall contain the new variable.
950 *ptr The pointer to the object to free.
951 *size The number of objects of type free_type to free in a sequence.
952 *free_type The type of the freed variable.
955 A memory, a pointer and an unsigned integer.
959 f.*type A pointer to the type information of the freed data object.
963 ir_node *new_Sync (int arity, ir_node **in)
964 -------------------------------------------
966 The Sync operation unifies several partial memory blocks. These blocks
967 have to be pairwise disjunct or the values in common locations have to
968 be identical. This operation allows to specify all operations that eventually
969 need several partial memory blocks as input with a single entrance by
970 unifying the memories with a preceding Sync operation.
973 arity The number of memories to syncronize.
974 **in An array of pointers to nodes that produce an output of
985 ir_node *new_Bad (void)
986 -----------------------
988 Returns the unique Bad node current_ir_graph->bad.
989 This node is used to express results of dead code elimination.
991 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj)
992 ----------------------------------------------------------
994 Selects one entry of a tuple. This is a hidden `fat edge'.
997 *arg A node producing a tuple.
998 *mode The mode of the value to project.
999 proj The position of the value in the tuple.
1005 ir_node *new_Tuple (int arity, ir_node **in)
1006 --------------------------------------------
1008 Builds a Tuple from single values. This is needed to implement
1009 optimizations that remove a node that produced a tuple. The node can be
1010 replaced by the Tuple operation so that the following Proj nodes have not to
1011 be changed. (They are hard to find due to the implementation with pointers
1012 in only one direction.) The Tuple node is smaller than any other
1013 node, so that a node can be changed into a Tuple by just changing it's
1014 opcode and giving it a new in array.
1017 arity The number of tuple elements.
1018 **in An array containing pointers to the nodes producing the
1021 ir_node *new_Id (ir_node *val, ir_mode *mode)
1022 ---------------------------------------------
1024 The single output of the Id operation is it's input. Also needed
1028 COPING WITH DATA OBJECTS
1029 ========================
1031 Two kinds of data objects have to be distinguished for generating
1032 FIRM. First there are local variables other than arrays that are
1033 known to be alias free. Second there are all other data objects.
1034 For the first a common SSA representation is built, the second
1035 are modeled by saving them to memory. The memory is treated as
1036 a single local variable, the alias problem is hidden in the
1037 content of this variable.
1039 All values known in a Block are listed in the block's attribute,
1040 block.**graph_arr which is used to automatically insert Phi nodes.
1041 The following two funcions can be used to add a newly computed value
1042 to the array, or to get the producer of a value, i.e., the current
1045 inline void set_value (int pos, ir_node *value)
1046 -----------------------------------------------
1048 Has to be called for every assignment to a local variable. It
1049 adds the value to the array of used values at position pos. Pos
1050 has to be a unique identifier for an entry in the procedure's
1051 definition table. It can be used to access the value again.
1053 ir_node *get_value (int pos, ir_mode *mode)
1054 -------------------------------------------
1056 Returns the node defining the value referred to by pos. If the
1057 value is not defined in this block a Phi node is generated and
1058 all definitions reaching this Phi node are collected. It can
1059 happen that the algorithm allocates an unnecessary Phi node,
1060 e.g. if there is only one definition of this value, but this
1061 definition reaches the currend block on several different
1062 paths. This Phi node will be eliminated if optimizations are
1063 turned on right after it's creation.
1066 There are two special routines for the global store:
1068 inline void set_store (ir_node *store)
1069 --------------------------------------
1071 Adds the store to the array of known values at a reserved
1074 inline ir_node *get_store (void)
1075 --------------------------------
1077 Returns the node defining the actual store.
1085 # include "common.h"
1086 # include "irgraph.h"
1087 # include "irnode.h"
1088 # include "irmode.h"
1089 # include "entity.h"
1094 #if USE_EXPICIT_PHI_IN_STACK
1095 /* A stack needed for the automatic Phi node construction in constructor
1097 typedef struct Phi_in_stack Phi_in_stack;
1100 /***************************************************************************/
1101 /* The raw interface */
1103 ir_node *new_r_Block (ir_graph *irg, int arity, ir_node **in);
1104 ir_node *new_r_Start (ir_graph *irg, ir_node *block);
1105 ir_node *new_r_End (ir_graph *irg, ir_node *block);
1106 ir_node *new_r_Jmp (ir_graph *irg, ir_node *block);
1107 ir_node *new_r_Cond (ir_graph *irg, ir_node *block, ir_node *c);
1108 ir_node *new_r_Return (ir_graph *irg, ir_node *block,
1109 ir_node *store, int arity, ir_node **in);
1110 ir_node *new_r_Raise (ir_graph *irg, ir_node *block,
1111 ir_node *store, ir_node *obj);
1112 ir_node *new_r_Const (ir_graph *irg, ir_node *block,
1113 ir_mode *mode, tarval *con);
1114 ir_node *new_r_SymConst (ir_graph *irg, ir_node *block,
1115 type_or_id *value, symconst_kind symkind);
1116 ir_node *new_r_Sel (ir_graph *irg, ir_node *block, ir_node *store,
1117 ir_node *objptr, int n_index, ir_node **index,
1119 ir_node *new_r_Call (ir_graph *irg, ir_node *block, ir_node *store,
1120 ir_node *callee, int arity, ir_node **in,
1122 ir_node *new_r_Add (ir_graph *irg, ir_node *block,
1123 ir_node *op1, ir_node *op2, ir_mode *mode);
1124 ir_node *new_r_Sub (ir_graph *irg, ir_node *block,
1125 ir_node *op1, ir_node *op2, ir_mode *mode);
1126 ir_node *new_r_Minus (ir_graph *irg, ir_node *block,
1127 ir_node *op, ir_mode *mode);
1128 ir_node *new_r_Mul (ir_graph *irg, ir_node *block,
1129 ir_node *op1, ir_node *op2, ir_mode *mode);
1130 ir_node *new_r_Quot (ir_graph *irg, ir_node *block,
1131 ir_node *memop, ir_node *op1, ir_node *op2);
1132 ir_node *new_r_DivMod (ir_graph *irg, ir_node *block,
1133 ir_node *memop, ir_node *op1, ir_node *op2);
1134 ir_node *new_r_Div (ir_graph *irg, ir_node *block,
1135 ir_node *memop, ir_node *op1, ir_node *op2);
1136 ir_node *new_r_Mod (ir_graph *irg, ir_node *block,
1137 ir_node *memop, ir_node *op1, ir_node *op2);
1138 ir_node *new_r_Abs (ir_graph *irg, ir_node *block,
1139 ir_node *op, ir_mode *mode);
1140 ir_node *new_r_And (ir_graph *irg, ir_node *block,
1141 ir_node *op1, ir_node *op2, ir_mode *mode);
1142 ir_node *new_r_Or (ir_graph *irg, ir_node *block,
1143 ir_node *op1, ir_node *op2, ir_mode *mode);
1144 ir_node *new_r_Eor (ir_graph *irg, ir_node *block,
1145 ir_node *op1, ir_node *op2, ir_mode *mode);
1146 ir_node *new_r_Not (ir_graph *irg, ir_node *block,
1147 ir_node *op, ir_mode *mode);
1148 ir_node *new_r_Cmp (ir_graph *irg, ir_node *block,
1149 ir_node *op1, ir_node *op2);
1150 ir_node *new_r_Shl (ir_graph *irg, ir_node *block,
1151 ir_node *op, ir_node *k, ir_mode *mode);
1152 ir_node *new_r_Shr (ir_graph *irg, ir_node *block,
1153 ir_node *op, ir_node *k, ir_mode *mode);
1154 ir_node *new_r_Shrs (ir_graph *irg, ir_node *block,
1155 ir_node *op, ir_node *k, ir_mode *mode);
1156 ir_node *new_r_Rot (ir_graph *irg, ir_node *block,
1157 ir_node *op, ir_node *k, ir_mode *mode);
1158 ir_node *new_r_Conv (ir_graph *irg, ir_node *block,
1159 ir_node *op, ir_mode *mode);
1160 ir_node *new_r_Phi (ir_graph *irg, ir_node *block, int arity,
1161 ir_node **in, ir_mode *mode);
1162 ir_node *new_r_Load (ir_graph *irg, ir_node *block,
1163 ir_node *store, ir_node *adr);
1164 ir_node *new_r_Store (ir_graph *irg, ir_node *block,
1165 ir_node *store, ir_node *adr, ir_node *val);
1166 ir_node *new_r_Alloc (ir_graph *irg, ir_node *block, ir_node *store,
1167 ir_node *size, type *alloc_type, where_alloc where);
1168 ir_node *new_r_Free (ir_graph *irg, ir_node *block, ir_node *store,
1169 ir_node *ptr, ir_node *size, type *free_type);
1170 ir_node *new_r_Sync (ir_graph *irg, ir_node *block, int arity, ir_node **in);
1171 ir_node *new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg,
1172 ir_mode *mode, long proj);
1173 ir_node *new_r_Tuple (ir_graph *irg, ir_node *block,
1174 int arity, ir_node **in);
1175 ir_node *new_r_Id (ir_graph *irg, ir_node *block,
1176 ir_node *val, ir_mode *mode);
1177 ir_node *new_r_Bad ();
1180 /*************************************************************************/
1181 /* The block oriented interface */
1183 /* Sets the current block in which the following constructors place the
1184 nodes they construct. */
1185 void switch_block (ir_node *target);
1187 /* Chris: please rename the Block constructor:
1188 new_Block to new_immBlock
1189 and add a new one so dass das dann so aussieht:
1190 passe die Beispeilprogramme an! */
1192 ir_node *new_Block(int arity, ir_node **in); /* creates mature Block */
1194 ir_node *new_Block (void);
1196 ir_node *new_Start (void);
1197 ir_node *new_End (void);
1198 ir_node *new_Jmp (void);
1199 ir_node *new_Cond (ir_node *c);
1200 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
1201 ir_node *new_Raise (ir_node *store, ir_node *obj);
1202 ir_node *new_Const (ir_mode *mode, tarval *con);
1203 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
1204 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
1205 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity, ir_node **in,
1207 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
1209 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
1210 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
1211 ir_node *new_Minus (ir_node *op, ir_mode *mode);
1212 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
1213 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
1214 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
1215 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
1216 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
1217 ir_node *new_Abs (ir_node *op, ir_mode *mode);
1218 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
1219 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
1220 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
1221 ir_node *new_Not (ir_node *op, ir_mode *mode);
1222 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
1223 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
1224 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
1225 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
1226 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
1227 ir_node *new_Conv (ir_node *op, ir_mode *mode);
1228 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode);
1229 ir_node *new_Load (ir_node *store, ir_node *addr);
1230 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
1231 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
1233 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
1235 ir_node *new_Sync (int arity, ir_node **in);
1236 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
1237 ir_node *new_Tuple (int arity, ir_node **in);
1238 ir_node *new_Id (ir_node *val, ir_mode *mode);
1239 ir_node *new_Bad (void);
1241 /***********************************************************************/
1242 /* The comfortable interface. */
1243 /* Supports automatic Phi node construction. */
1244 /* All routines of the block oriented interface except new_Block are */
1247 /** Block construction **/
1248 /* immature Block without predecessors */
1249 ir_node *new_immBlock (void);
1251 /* Add a control flow edge to an immature block. */
1252 void add_in_edge (ir_node *immblock, ir_node *jmp);
1254 /* fixes the number of predecessors of a block. */
1255 void mature_block (ir_node *block);
1257 /** Parameter administration **/
1258 /* Read a value from the array with the local variables. Use this
1259 function to obtain the last definition of the value associated with
1261 ir_node *get_value (int pos, ir_mode *mode);
1263 /* Write a value in the array with the local variables. Use this function
1264 to remember a new definition of the value associated with pos. */
1265 void set_value (int pos, ir_node *value);
1268 Use this function to get the most recent version of the store (type M).
1269 Internally it does the same as get_value. */
1270 ir_node *get_store (void);
1272 /* Write a store. */
1273 void set_store (ir_node *store);
1275 /* This function is for internal use only. It is visible as it is needed
1276 in irgraph.c to create the stack that is needed for automatic Phi
1278 #if USE_EXPICIT_PHI_IN_STACK
1279 Phi_in_stack *new_Phi_in_stack();
1282 /**************************************************************************/
1283 /* initialize ir construction */
1284 void init_cons (void);
1287 # endif /* _IRCONS_H_ */