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".
255 * An even less comfortable interface where the block needs to be specified
256 explicitly. This is called the "raw" interface. (new_r_<Node>
259 To use the functionality of the comfortable interface correctly the Front
260 End needs to follow certain protocols. This is explained in the following.
261 To build a correct IR with the other interfaces study the semantics of
262 the firm node (See tech-reprot UKA 1999-44). For the construction of
263 types and entities see the documentation in those modules.
265 First the Frontend needs to decide which variables and values used in
266 a procedure can be represented by dataflow edges. These are variables
267 that need not be saved to memory as they cause no side effects visible
268 out of the procedure. In general these are all compiler generated
269 variables and simple local variables of the procedure as integers,
270 reals and pointers. The frontend has to count and number these variables.
272 First an ir_graph needs to be constructed with new_ir_graph. The
273 constructor gets the number of local variables. The graph is hold in the
276 Now the construction of the procedure can start. Several basic blocks can
277 be constructed in parallel, but the code within each block needs to
278 be constructed (almost) in program order.
280 A global variable holds the current basic block. All (non block) nodes
281 generated are added to this block. The current block can be set with
282 switch_block(block). If several blocks are constructed in parallel block
283 switches need to be performed constantly.
285 To generate a Block node (with the comfortable interface) it's predecessor
286 control flow nodes need not be known. In case of cyclic control flow these
287 can not be known when the block is constructed. With add_in_edge(block,
288 cfnode) predecessors can be added to the block. If all predecessors are
289 added to the block mature_block(b) needs to be called. Calling mature_block
290 early improves the efficiency of the Phi node construction algorithm.
291 But if several blocks are constructed at once, mature_block must only
292 be called after performing all set_values and set_stores in the block!
293 (See documentation of new_immBlock constructor.)
295 The constructors of arithmetic nodes require that their predecessors
296 are mentioned. Sometimes these are available in the Frontend as the
297 predecessors have just been generated by the frontend. If they are local
298 values the predecessors can be obtained from the library with a call to
299 get_value(local_val_nr). (local_val_nr needs to be administered by
300 the Frontend.) A call to get_value triggers the generation of Phi nodes.
301 If an arithmetic operation produces a local value this value needs to be
302 passed to the library by set_value(node, local_val_nr).
303 In straight line code these two operations just remember and return the
304 pointer to nodes producing the value. If the value passes block boundaries
305 Phi nodes can be inserted.
306 Similar routines exist to manage the Memory operands: set_store and
309 Several nodes produce more than one result. An example is the Div node.
310 Such nodes return tuples of values. From these individual values can be
311 extracted by proj nodes.
313 The following example illustrates the construction of a simple basic block
314 with two predecessors stored in variables cf_pred1 and cf_pred2, containing
317 and finally jumping to an other block. The variable a got the local_val_nr
320 ir_node *this_block, *cf_pred1, *cf_pred2, *a_val, *mem, *div, *res, *cf_op;
322 this_block = new_immBlock();
323 add_in_edge(this_block, cf_pred1);
324 add_in_edge(this_block, cf_pred2);
325 mature_block(this_block);
326 a_val = get_value(17, mode_I);
328 div = new_Div(mem, a_val, a_val);
329 mem = new_Proj(div, mode_M, 0); * for the numbers for Proj see docu *
330 res = new_Proj(div, mode_I, 2);
335 For further information look at the documentation of the nodes and
336 constructors and at the paragraph COPING WITH DATA OBJECTS at the
337 end of this documentation.
339 The comfortable interface contains the following routines further explained
342 ir_node *new_immBlock (void);
343 ir_node *new_Start (void);
344 ir_node *new_End (void);
345 ir_node *new_Jmp (void);
346 ir_node *new_Cond (ir_node *c);
347 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
348 ir_node *new_Raise (ir_node *store, ir_node *obj);
349 ir_node *new_Const (ir_mode *mode, tarval *con);
350 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
351 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
352 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity,
353 ir_node **in, entity *ent);
354 ir_node *new_Call (ir_node *store, ir_node *callee, int arity,
355 ir_node **in, type_method *type);
356 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
357 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
358 ir_node *new_Minus (ir_node *op, ir_mode *mode);
359 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
360 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
361 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
362 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
363 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
364 ir_node *new_Abs (ir_node *op, ir_mode *mode);
365 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
366 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
367 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
368 ir_node *new_Not (ir_node *op, ir_mode *mode);
369 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
370 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
371 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
372 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
373 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
374 ir_node *new_Conv (ir_node *op, ir_mode *mode);
375 ir_node *new_Load (ir_node *store, ir_node *addr);
376 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
377 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
379 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
381 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
383 void add_in_edge (ir_node *block, ir_node *jmp);
384 void mature_block (ir_node *block);
385 void switch_block (ir_node *target);
386 ir_node *get_value (int pos, ir_mode *mode);
387 void set_value (int pos, ir_node *value);
388 ir_node *get_store (void);
389 void set_store (ir_node *store);
392 IR_NODES AND CONSTRUCTORS FOR IR_NODES
393 =======================================
395 All ir_nodes are defined by a common data structure. They are distinguished
396 by their opcode and differ in the number of their attributes.
398 The constructor for the block node sets current_block to itself.
399 Const nodes are always added to the start block.
400 All other constructors add the created node to the current_block.
401 swich_block(block) allows to set the current block to block.
403 Watch for my inconsistent use of input and predecessor (dataflow view)
404 and `the node points to' (implementation view).
406 The following description of the nodes lists four properties them if these
408 - the parameters to the constructor
409 - the inputs of the Firm node
410 - the outputs of the Firm node
411 - attributes to the node
416 ir_node *new_immBlock (void)
417 ----------------------------
419 Creates a new block. Sets current_block to itself. When a new block is
420 created it cannot be known how many predecessors this block will have in the
421 control flow graph. Therefore the list of inputs can not be fixed at
422 creation. Predecessors can be added with add_in_edge (block, control flow
423 operation). With every added predecessor the number of inputs to Phi nodes
426 The block can be completed by mature_block(block) if all predecessors are
427 known. If several blocks are built at once, mature_block can only be called
428 after set_value has been called for all values that are life at the end
429 of the block. This is necessary so that Phi nodes created by mature_block
430 get the right predecessors in case of cyclic dependencies. If all set_values
431 of this block are called after maturing it and before calling get_value
432 in some block that is control flow dependent on this block, the construction
435 Example for faulty ir construction: (draw the graph on a paper and you'll
438 block_before_loop = new_block();
440 mature_block(block_before_loop);
441 before2header = new_Jmp;
443 loop_header = new_block ();
444 header2body - new_Jmp();
446 loop_body = new_block ();
447 body2header = new_Jmp();
449 add_in_edge(loop_header, before2header);
450 add_in_edge(loop_header, body2header);
451 add_in_edge(loop_body, header2body);
453 mature_block(loop_header);
454 mature_block(loop_body);
456 get_value(loop_body, x); // gets the Phi in loop_header
457 set_value(loop_header, x); // sets the value the above get_value should
460 Mature_block also fixes the number of inputs to the Phi nodes. Mature_block
461 should be called as early as possible, as afterwards the generation of Phi
462 nodes is more efficient.
465 There is an input for each control flow predecessor of the block.
466 The input points to an instruction producing an output of type X.
467 Possible predecessors: Start, Jmp, Cond, Raise or Return or any node
468 possibly causing an exception. (Often the real predecessors are Projs.)
470 Mode BB (R), all nodes belonging to this block should consume this output.
471 As they are strict (except Block and Phi node) it is a necessary condition
472 that the block node executed before any other node in this block executes.
474 block.matured Indicates whether the block is mature.
476 This attribute contains all local values valid in this
477 block. This is needed to build the Phi nodes and removed
478 if the graph is complete. This field is used by the
479 internal construction algorithm and should not be accessed
483 ir_node *new_Block (int arity, ir_node **in)
484 --------------------------------------------
486 Creates a new Block with the given list of predecessors. This block
490 CONTROL FLOW OPERATIONS
491 -----------------------
493 In each block there must be exactly one of the control flow
494 operations Start, End, Jmp, Cond, Return or Raise. The output of a
495 control flow operation points to the block to be executed next.
497 ir_node *new_Start (void)
498 -------------------------
500 Creates a start node. Not actually needed public. There is only one such
501 node in each procedure which is automatically created by new_ir_graph.
504 No inputs except the block it belogns to.
506 A tuple of 4 (5, 6) distinct values. These are labeled by the following
507 projection numbers (pns_number):
509 mode X, points to the first block to be executed.
511 mode M, the global store
512 * pns_frame_base mode P, a pointer to the base of the procedures
514 * pns_globals mode P, a pointer to the part of the memory containing
516 * pns_args mode T, a tuple containing all arguments of the procedure.
519 ir_node *new_End (void)
520 -----------------------
522 Creates an end node. Not actually needed public. There is only one such
523 node in each procedure which is automatically created by new_ir_graph.
526 No inputs except the block it belongs to.
530 ir_node *new_Jmp (void)
531 -----------------------
536 The block the node belongs to
538 Control flow to the next block.
540 ir_node *new_Cond (ir_node *c)
541 ------------------------------
543 Creates a Cond node. There are two versions of this node.
549 A tuple of two control flows. The first is taken if the input is
550 false, the second if it is true.
554 A value of mode I_u. (i)
556 A tuple of n control flows. If the Cond's input is i, control
557 flow will procede along output i. If the input is >= n control
558 flow proceeds along output n.
560 ir_node *new_Return (in_node *store, int arity, ir_node **in)
561 -------------------------------------------------------------
563 The return node has as inputs the results of the procedure. It
564 passes the control flow to the end_block.
570 Control flow to the end block.
572 ir_node *new_Raise (ir_node *store, ir_node *obj)
573 -------------------------------------------------
575 Raises an exception. Unconditional change of control flow. Writes
576 an explicit Except variable to memory to pass it to the exception
577 handler. See TechReport 1999-14, chapter Exceptions.
581 A pointer to the Except variable.
583 A tuple of control flow and the changed memory state. The control flow
584 points to the exception handler if it is definied in this procedure,
585 else it points to the end_block.
591 ir_node *new_Const (ir_mode *mode, tarval *con)
592 -----------------------------------------------
594 Creates a constant in the constant table and adds a Const node
595 returning this value to the start block.
598 *mode The mode of the constant.
599 *con Points to an entry in the constant table.
600 This pointer is added to the attributes of
601 the node (self->attr.con)
603 No inputs except the block it belogns to.
607 attr.con A tarval* pointer to the proper entry in the constant
610 ir_node *new_SymConst (type *type, symconst_kind kind)
611 ------------------------------------------------------------
613 There are three kinds of symbolic constants:
614 type_tag The symbolic constant represents a type tag.
615 size The symbolic constant represents the size of a class.
616 link_info Information for the linker, e.g. the name of a global
620 kind The kind of the symbolic constant: type_tag, size or link_info.
621 *type Points to the type the tag stands for or to the type
622 whose size is represented by the constant.
625 No inputs except the block it belogns to.
627 An unsigned integer (I_u) or a pointer (P).
630 attr.i.num The symconst_kind, i.e. one of
634 If the attr.i.num is type_tag or size, the node contains an attribute
635 attr.i.*type A pointer to a type_class.
636 if it is linkage_ptr_info it contains
637 attr.i.*ptrinfo A ident holding information for the linker.
642 ir_node *new_simpleSel (ir_node *store, ir_node *frame, entity *sel)
643 --------------------------------------------------------------------
646 Selects an entity from a compound type. This entity can be a field or
650 *store The memory in which the object the entity should be selected
652 *frame The pointer to the object.
653 *sel The entity to select.
656 The memory containing the object.
657 A pointer to the object.
660 A pointer to the selected entity.
662 attr.sel Pointer to the entity
665 ir_node *new_Sel (ir_node *store, ir_node *frame, int arity, ir_node **in,
666 --------------------------------------------------------------------------
670 Selects a field from an array type. The entity has as owner the array, as
671 type the arrays element type. The indexes to access an array element are
675 *store The memory in which the object the entity should be selected from
677 *frame The pointer to the object.
678 *arity number of array indexes.
679 *in array with index inputs to the node.
680 *sel The entity to select.
683 The memory containing the object.
684 A pointer to the object.
685 As much unsigned integer as there are array expressions.
687 A pointer to the selected entity.
689 attr.sel Pointer to the entity
691 The constructors new_Sel and new_simpleSel generate the same ir nodes.
692 simpleSel just sets the arity of the index inputs to zero.
695 ARITHMETIC OPERATIONS
696 ---------------------
698 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
699 ----------------------------------------------------------------------------
703 Creates a procedure call.
706 *store The actual store.
707 *callee A pointer to the called procedure.
708 arity The number of procedure parameters.
709 **in An array with the pointers to the parameters.
710 The constructor copies this array.
711 *type Type information of the procedure called.
714 The store, the callee and the parameters.
716 A tuple containing the eventually changed store and the procedure
719 attr.call Contains the type information for the procedure.
721 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode)
722 ------------------------------------------------------------
726 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode)
727 ------------------------------------------------------------
731 ir_node *new_Minus (ir_node *op, ir_mode *mode)
732 -----------------------------------------------
734 This constructor is for unary Minus operations on floating point
735 values. Such a Minus can trap if it is implemented as a Sub from
736 zero due to rounding errors.
738 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode)
739 ------------------------------------------------------------
743 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2)
744 --------------------------------------------------------------
746 Quot performs exact division of floating point numbers. It's mode
747 is Tuple, the mode of the result must be annotated to the Proj
748 that extracts the result of the arithmetic operations.
751 The store needed to model exceptions and the two operands.
753 A tuple contaning a memory and a execution for modeling exceptions
754 and the result of the arithmetic operation.
756 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2)
757 ----------------------------------------------------------------
759 Performs Div and Mod on interger values.
762 A tuple contaning a memory and a execution for modeling exceptions
763 and the two result of the arithmetic operations.
765 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2)
766 -------------------------------------------------------------
770 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2)
771 -------------------------------------------------------------
775 ir_node *new_Abs (ir_node *op, ir_mode *mode)
776 ---------------------------------------------
780 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode)
781 ------------------------------------------------------------
785 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode)
786 -----------------------------------------------------------
790 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode)
791 ------------------------------------------------------------
795 ir_node *new_Not (ir_node *op, ir_mode *mode)
796 ---------------------------------------------
798 This node constructs a constant where all bits are set to one
799 and a Eor of this constant and the operator. This simulates a
802 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode)
803 ---------------------------------------------------------
807 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode)
808 ---------------------------------------------------------
810 Logic shift right, i.e., zero extended.
813 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode)
814 ----------------------------------------------------------
816 Arithmetic shift right, i.e., sign extended.
818 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode)
819 ---------------------------------------------------------
821 Rotates the operand to the (right??) by k bits.
823 ir_node *new_Conv (ir_node *op, ir_mode *mode)
824 ---------------------------------------------
826 Mode conversion. For allowed conversions see UKA Tech Report
829 ir_node *new_Cmp (ir_node *op1, ir_node *op2)
830 ---------------------------------------------
833 The two values to be compared.
835 A 16-tuple containing the results of the 16 different comparisons.
836 The following is a list giving the comparisons and a projection
837 number (pnc_number) to use in Proj nodes to extract the proper result.
845 Leg less, equal or greater = ordered
847 Ue unordered or equal
849 Ule unordered, less or equal
850 Ug unordered or greater
851 Uge unordered, greater or equal
852 Ne unordered, less or greater = not equal
860 In general, Phi nodes are automaitcally inserted. In some cases, if
861 all predecessors of a block are known, an explicit Phi node constructor
862 is needed. E.g., to construct a FIRM graph for a statement as
865 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode)
866 ---------------------------------------------------------
868 Creates a Phi node. The in's order has to correspond to the order
869 of in's of current_block. This is not checked by the library!
872 arity number of predecessors
873 **in array with predecessors
874 *mode The mode of it's inputs and output.
876 A Phi node has as many inputs as the block it belongs to.
877 Each input points to a definition of the same value on a
878 different path in the control flow.
880 The definition valid in this block.
883 OPERATIONS TO MANAGE MEMORY EXPLICITLY
884 --------------------------------------
886 ir_node *new_Load (ir_node *store, ir_node *addr)
887 ----------------------------------------------------------------
889 The Load operation reads a value from memory.
892 *store The current memory.
893 *addr A pointer to the variable to be read in this memory.
894 *mode The mode of the loaded value.
897 The memory and a pointer to a variable in this memory.
899 A tuple of the memory, a control flow to be taken in case of
900 an exception and the loaded value.
902 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val)
903 ----------------------------------------------------------------
905 The Store operation writes a value to a variable in memory.
908 The memory, a pointer to a variable in this memory and the value
909 to write to this variable.
911 A tuple of the changed memory and a control flow to be taken in
912 case of an exception.
914 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
915 --------------------------------------------------------------------
919 The Alloc node allocates a new variable. It can be specified whether the
920 variable should be allocated to the stack or to the heap.
923 *store The memory which shall contain the new variable.
924 ** *size The number of bytes to allocate. Old. **
925 *size We decided that the size easily can be derived from the type.
926 This field is for allocating arrays, i.e., it gives the multiple
927 of the size of alloc_type to allocate memory for.
928 *alloc_type The type of the allocated variable.
929 where Where to allocate the variable, either heap_alloc or stack_alloc.
932 A memory and an unsigned integer.
934 A tuple of the changed memory, a control flow to be taken in
935 case of an exception and the pointer to the new variable.
937 a.where Indicates where the variable is allocated.
938 a.*type A pointer to the class the allocated data object
941 ir_node *new_Free (ir_node *store, ir_node *ptr, type *free_type)
942 ------------------------------------------------------------------
944 The Free node frees memory of the given variable.
947 *store The memory which shall contain the new variable.
948 *ptr The pointer to the object to free.
949 *size The number of objects of type free_type to free in a sequence.
950 *free_type The type of the freed variable.
953 A memory, a pointer and an unsigned integer.
957 f.*type A pointer to the type information of the freed data object.
961 ir_node *new_Sync (int arity, ir_node **in)
962 -------------------------------------------
964 The Sync operation unifies several partial memory blocks. These blocks
965 have to be pairwise disjunct or the values in common locations have to
966 be identical. This operation allows to specify all operations that eventually
967 need several partial memory blocks as input with a single entrance by
968 unifying the memories with a preceding Sync operation.
971 arity The number of memories to syncronize.
972 **in An array of pointers to nodes that produce an output of
983 ir_node *new_Bad (void)
984 -----------------------
986 Returns the unique Bad node current_ir_graph->bad.
987 This node is used to express results of dead code elimination.
989 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj)
990 ----------------------------------------------------------
992 Selects one entry of a tuple. This is a hidden `fat edge'.
995 *arg A node producing a tuple.
996 *mode The mode of the value to project.
997 proj The position of the value in the tuple.
1003 ir_node *new_Tuple (int arity, ir_node **in)
1004 --------------------------------------------
1006 Builds a Tuple from single values. This is needed to implement
1007 optimizations that remove a node that produced a tuple. The node can be
1008 replaced by the Tuple operation so that the following Proj nodes have not to
1009 be changed. (They are hard to find due to the implementation with pointers
1010 in only one direction.) The Tuple node is smaller than any other
1011 node, so that a node can be changed into a Tuple by just changing it's
1012 opcode and giving it a new in array.
1015 arity The number of tuple elements.
1016 **in An array containing pointers to the nodes producing the
1019 ir_node *new_Id (ir_node *val, ir_mode *mode)
1020 ---------------------------------------------
1022 The single output of the Id operation is it's input. Also needed
1026 COPING WITH DATA OBJECTS
1027 ========================
1029 Two kinds of data objects have to be distinguished for generating
1030 FIRM. First there are local variables other than arrays that are
1031 known to be alias free. Second there are all other data objects.
1032 For the first a common SSA representation is built, the second
1033 are modeled by saving them to memory. The memory is treated as
1034 a single local variable, the alias problem is hidden in the
1035 content of this variable.
1037 All values known in a Block are listed in the block's attribute,
1038 block.**graph_arr which is used to automatically insert Phi nodes.
1039 The following two funcions can be used to add a newly computed value
1040 to the array, or to get the producer of a value, i.e., the current
1043 inline void set_value (int pos, ir_node *value)
1044 -----------------------------------------------
1046 Has to be called for every assignment to a local variable. It
1047 adds the value to the array of used values at position pos. Pos
1048 has to be a unique identifier for an entry in the procedure's
1049 definition table. It can be used to access the value again.
1051 ir_node *get_value (int pos, ir_mode *mode)
1052 -------------------------------------------
1054 Returns the node defining the value referred to by pos. If the
1055 value is not defined in this block a Phi node is generated and
1056 all definitions reaching this Phi node are collected. It can
1057 happen that the algorithm allocates an unnecessary Phi node,
1058 e.g. if there is only one definition of this value, but this
1059 definition reaches the currend block on several different
1060 paths. This Phi node will be eliminated if optimizations are
1061 turned on right after it's creation.
1064 There are two special routines for the global store:
1066 inline void set_store (ir_node *store)
1067 --------------------------------------
1069 Adds the store to the array of known values at a reserved
1072 inline ir_node *get_store (void)
1073 --------------------------------
1075 Returns the node defining the actual store.
1083 # include "irgraph.h"
1084 # include "irnode.h"
1085 # include "irmode.h"
1086 # include "entity.h"
1091 #if USE_EXPICIT_PHI_IN_STACK
1092 /* A stack needed for the automatic Phi node construction in constructor
1094 typedef struct Phi_in_stack Phi_in_stack;
1097 /***************************************************************************/
1098 /* The raw interface */
1100 ir_node *new_r_Block (ir_graph *irg, int arity, ir_node **in);
1101 ir_node *new_r_Start (ir_graph *irg, ir_node *block);
1102 ir_node *new_r_End (ir_graph *irg, ir_node *block);
1103 ir_node *new_r_Jmp (ir_graph *irg, ir_node *block);
1104 ir_node *new_r_Cond (ir_graph *irg, ir_node *block, ir_node *c);
1105 ir_node *new_r_Return (ir_graph *irg, ir_node *block,
1106 ir_node *store, int arity, ir_node **in);
1107 ir_node *new_r_Raise (ir_graph *irg, ir_node *block,
1108 ir_node *store, ir_node *obj);
1109 ir_node *new_r_Const (ir_graph *irg, ir_node *block,
1110 ir_mode *mode, tarval *con);
1111 ir_node *new_r_SymConst (ir_graph *irg, ir_node *block,
1112 type_or_id *value, symconst_kind symkind);
1113 ir_node *new_r_Sel (ir_graph *irg, ir_node *block, ir_node *store,
1114 ir_node *objptr, int n_index, ir_node **index,
1116 ir_node *new_r_Call (ir_graph *irg, ir_node *block, ir_node *store,
1117 ir_node *callee, int arity, ir_node **in,
1119 ir_node *new_r_Add (ir_graph *irg, ir_node *block,
1120 ir_node *op1, ir_node *op2, ir_mode *mode);
1121 ir_node *new_r_Sub (ir_graph *irg, ir_node *block,
1122 ir_node *op1, ir_node *op2, ir_mode *mode);
1123 ir_node *new_r_Minus (ir_graph *irg, ir_node *block,
1124 ir_node *op, ir_mode *mode);
1125 ir_node *new_r_Mul (ir_graph *irg, ir_node *block,
1126 ir_node *op1, ir_node *op2, ir_mode *mode);
1127 ir_node *new_r_Quot (ir_graph *irg, ir_node *block,
1128 ir_node *memop, ir_node *op1, ir_node *op2);
1129 ir_node *new_r_DivMod (ir_graph *irg, ir_node *block,
1130 ir_node *memop, ir_node *op1, ir_node *op2);
1131 ir_node *new_r_Div (ir_graph *irg, ir_node *block,
1132 ir_node *memop, ir_node *op1, ir_node *op2);
1133 ir_node *new_r_Mod (ir_graph *irg, ir_node *block,
1134 ir_node *memop, ir_node *op1, ir_node *op2);
1135 ir_node *new_r_Abs (ir_graph *irg, ir_node *block,
1136 ir_node *op, ir_mode *mode);
1137 ir_node *new_r_And (ir_graph *irg, ir_node *block,
1138 ir_node *op1, ir_node *op2, ir_mode *mode);
1139 ir_node *new_r_Or (ir_graph *irg, ir_node *block,
1140 ir_node *op1, ir_node *op2, ir_mode *mode);
1141 ir_node *new_r_Eor (ir_graph *irg, ir_node *block,
1142 ir_node *op1, ir_node *op2, ir_mode *mode);
1143 ir_node *new_r_Not (ir_graph *irg, ir_node *block,
1144 ir_node *op, ir_mode *mode);
1145 ir_node *new_r_Cmp (ir_graph *irg, ir_node *block,
1146 ir_node *op1, ir_node *op2);
1147 ir_node *new_r_Shl (ir_graph *irg, ir_node *block,
1148 ir_node *op, ir_node *k, ir_mode *mode);
1149 ir_node *new_r_Shr (ir_graph *irg, ir_node *block,
1150 ir_node *op, ir_node *k, ir_mode *mode);
1151 ir_node *new_r_Shrs (ir_graph *irg, ir_node *block,
1152 ir_node *op, ir_node *k, ir_mode *mode);
1153 ir_node *new_r_Rot (ir_graph *irg, ir_node *block,
1154 ir_node *op, ir_node *k, ir_mode *mode);
1155 ir_node *new_r_Conv (ir_graph *irg, ir_node *block,
1156 ir_node *op, ir_mode *mode);
1157 ir_node *new_r_Phi (ir_graph *irg, ir_node *block, int arity,
1158 ir_node **in, ir_mode *mode);
1159 ir_node *new_r_Load (ir_graph *irg, ir_node *block,
1160 ir_node *store, ir_node *adr);
1161 ir_node *new_r_Store (ir_graph *irg, ir_node *block,
1162 ir_node *store, ir_node *adr, ir_node *val);
1163 ir_node *new_r_Alloc (ir_graph *irg, ir_node *block, ir_node *store,
1164 ir_node *size, type *alloc_type, where_alloc where);
1165 ir_node *new_r_Free (ir_graph *irg, ir_node *block, ir_node *store,
1166 ir_node *ptr, ir_node *size, type *free_type);
1167 ir_node *new_r_Sync (ir_graph *irg, ir_node *block, int arity, ir_node **in);
1168 ir_node *new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg,
1169 ir_mode *mode, long proj);
1170 ir_node *new_r_Tuple (ir_graph *irg, ir_node *block,
1171 int arity, ir_node **in);
1172 ir_node *new_r_Id (ir_graph *irg, ir_node *block,
1173 ir_node *val, ir_mode *mode);
1174 ir_node *new_r_Bad (ir_node *block);
1177 /*************************************************************************/
1178 /* The block oriented interface */
1180 /* Sets the current block in which the following constructors place the
1181 nodes they construct. */
1182 void switch_block (ir_node *target);
1184 /* Chris: please rename the Block constructor:
1185 new_Block to new_immBlock
1186 and add a new one so dass das dann so aussieht:
1187 passe die Beispeilprogramme an! */
1189 ir_node *new_Block(int arity, ir_node **in); /* creates mature Block */
1191 ir_node *new_Block (void);
1193 ir_node *new_Start (void);
1194 ir_node *new_End (void);
1195 ir_node *new_Jmp (void);
1196 ir_node *new_Cond (ir_node *c);
1197 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
1198 ir_node *new_Raise (ir_node *store, ir_node *obj);
1199 ir_node *new_Const (ir_mode *mode, tarval *con);
1200 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
1201 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
1202 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity, ir_node **in,
1204 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
1206 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
1207 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
1208 ir_node *new_Minus (ir_node *op, ir_mode *mode);
1209 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
1210 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
1211 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
1212 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
1213 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
1214 ir_node *new_Abs (ir_node *op, ir_mode *mode);
1215 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
1216 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
1217 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
1218 ir_node *new_Not (ir_node *op, ir_mode *mode);
1219 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
1220 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
1221 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
1222 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
1223 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
1224 ir_node *new_Conv (ir_node *op, ir_mode *mode);
1225 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode);
1226 ir_node *new_Load (ir_node *store, ir_node *addr);
1227 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
1228 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
1230 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
1232 ir_node *new_Sync (int arity, ir_node **in);
1233 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
1234 ir_node *new_Tuple (int arity, ir_node **in);
1235 ir_node *new_Id (ir_node *val, ir_mode *mode);
1236 ir_node *new_Bad (void);
1238 /***********************************************************************/
1239 /* The comfortable interface. */
1240 /* Supports automatic Phi node construction. */
1241 /* All routines of the block oriented interface except new_Block are */
1244 /** Block construction **/
1245 /* immature Block without predecessors */
1246 ir_node *new_immBlock (void);
1248 /* Add a control flow edge to an immature block. */
1249 void add_in_edge (ir_node *immblock, ir_node *jmp);
1251 /* fixes the number of predecessors of a block. */
1252 void mature_block (ir_node *block);
1254 /** Parameter administration **/
1255 /* Read a value from the array with the local variables. Use this
1256 function to obtain the last definition of the value associated with
1258 ir_node *get_value (int pos, ir_mode *mode);
1260 /* Write a value in the array with the local variables. Use this function
1261 to remember a new definition of the value associated with pos. */
1262 void set_value (int pos, ir_node *value);
1265 Use this function to get the most recent version of the store (type M).
1266 Internally it does the same as get_value. */
1267 ir_node *get_store (void);
1269 /* Write a store. */
1270 void set_store (ir_node *store);
1272 /* This function is for internal use only. It is visible as it is needed
1273 in irgraph.c to create the stack that is needed for automatic Phi
1275 #if USE_EXPICIT_PHI_IN_STACK
1276 Phi_in_stack *new_Phi_in_stack();
1279 /**************************************************************************/
1280 /* initialize ir construction */
1281 void init_cons (void);
1284 # endif /* _IRCONS_H_ */