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.
24 /****h* libfirm/ircons
31 This file documents all datatypes and constructors needed to
32 build a FIRM representation of a pocedure. The constructors are
33 also implemented in this file.
35 The documentation also gives a short manual how to use the library.
37 For extensive documentation of FIRM see UKA Techreport 1999-14.
45 This struct contains all information about a procedure.
46 It's allocated directly to memory.
48 The fields of ir_graph:
50 *ent The entity describing this procedure.
52 The beginning and end of a graph:
54 *start_block This ir_node is the block that contains the unique
55 start node of the procedure. With it it contains
56 the Proj's on starts results.
57 Further all Const nodes are placed in the start block.
58 *start This ir_node is the unique start node of the procedure.
60 *end_block This ir_node is the block that contains the unique
61 end node of the procedure. This block contains no
63 *end This ir_node is the unique end node of the procedure.
65 The following nodes are Projs from the start node, held in ir_graph for
68 *frame The ir_node producing the pointer to the stack frame of
69 the procedure as output. This is the Proj node on the
70 third output of the start node. This output of the start
71 node is tagged as pns_frame_base. In FIRM most lokal
72 variables are modeled as data flow edges. Static
73 allocated arrays can not be represented as dataflow
74 edges. Therefore FIRM has to represent them in the stack
77 *globals This models a pointer to a space in the memory where
78 _all_ global things are held. Select from this pointer
79 with a Sel node the pointer to a global variable /
80 procedure / compiler known function... .
82 *args The ir_node that produces the arguments of the method as
83 it's result. This is a Proj node on the fourth output of
84 the start node. This output is tagged as pns_args.
86 *bad The bad node is an auxiliary node. It is needed only once,
87 so there is this globally reachable node.
89 Datastructures that are private to a graph:
91 *obst An obstack that contains all nodes.
93 *current_block A pointer to the current block. Any node created with
94 one of the node constructors (new_<opcode>) are assigned
95 to this block. It can be set with switch_block(block).
96 Only needed for ir construction.
98 params/n_loc An int giving the number of local variables in this
99 procedure. This is neede for ir construction. Name will
102 *value_table This hash table (pset) is used for global value numbering
103 for optimizing use in iropt.c.
105 *Phi_in_stack; a stack needed for automatic Phi construction, needed only
106 during ir construction.
108 visited A int used as flag to traverse the ir_graph.
110 block_visited A int used as a flag to traverse block nodes in the graph.
115 There are three kinds of nodes known to the ir: entities,
118 + ir_nodes are the actual nodes of the FIRM intermediate representation.
119 They represent operations on the data of the program and control flow
122 + entity ==> implemented in entity.h
123 Refers to a single entity of the compiled program, e.g. a field of a
124 class or a method. If a method or variable can not be assigned to
125 a method or class or the like, it is a global object.
127 + types ==> implemented in type.h
128 With types type information is represented. There are several type
131 Implementation of the FIRM operations: ir_node
132 ----------------------------------------------
134 Ir_nodes represent operations on the data of the program and control flow
135 operations. Examples of ir_nodes: Add, Jmp, Cmp
137 FIRM is a dataflow graph. A dataflow graph is a directed graph,
138 so that every node has incoming and outgoing edges. A node is
139 executable if every input at it's incoming edges is available.
140 Execution of the dataflow graph is started at the Start node which
141 has no incoming edges and ends when the End node executes, even if
142 there are still executable or not executed nodes. (Is this true,
143 or must all executable nodes be executed?) (There are exceptions
144 to the dataflow paradigma that all inputs have to be available
145 before a node can execute: Phi, Block. See UKA Techreport
148 The implementation of FIRM differs from the view as a dataflow
149 graph. To allow fast traversion of the graph edges are
150 implemented as C-pointers. Inputs to nodes are not ambiguous, the
151 results can be used by several other nodes. Each input can be
152 implemented as a single pointer to a predecessor node, outputs
153 need to be lists of pointers to successors. Therefore a node
154 contains pointers to it's predecessor so that the implementation is a
155 dataflow graph with reversed edges. It has to be traversed bottom
158 All nodes of the ir have the same basic structure. They are
159 distinguished by a field containing the opcode.
161 The fields of an ir_node:
163 kind A firm_kind tag containing k_ir_node. This is useful for
164 dynamically checking the type of a node.
166 *op This ir_op gives the opcode as a tag and a string
167 and the number of attributes of an ir_node. There is
168 one statically allocated struct ir_op for each opcode.
170 *mode The ir_mode of the operation represented by this firm
171 node. The mode of the operation is the mode of it's
172 result. A Firm mode is a datatype as known to the target,
173 not a type of the source language.
175 visit A flag for traversing the ir.
177 **in An array with pointers to the node's predecessors.
179 *link A pointer to an ir_node. With this pointer all Phi nodes
180 are attached to a Block, i.e., a Block points to it's
181 first Phi node, this node points to the second Phi node
182 in the Block and so fourth. Used in mature_block
183 to find all Phi nodes to be matured. It's also used to
184 annotate a node with a better, optimized version of it.
186 attr An attr struct containing the attributes of the nodes. The
187 attributes depend on the opcode of the node. The number
188 of these attributes is given in op.
192 Not yet documented. See irop.h.
196 Not yet documented. See irmode.h.
201 current_ir_graph Points to the current ir_graph. All constructors for
202 nodes add nodes to this graph.
204 ir_visited An int used as flag to traverse the ir_graph.
206 block_visited An int used as a flag to traverse block nodes in the
209 Others not yet documented.
213 CONSTRUCTOR FOR IR_GRAPH
214 ========================
216 ir_graph *new_ir_graph (entity *ent, int params);
217 -------------------------------------------------
219 This constructor generates the basic infrastructure needed to
220 represent a procedure in FIRM.
222 The parameters of new_ir_graph are:
224 *ent A pointer to an entity representing the procedure.
226 params An integer giving the number of local variables in the
229 It allocates an ir_graph and sets current_ir_graph to point to this
230 graph. Further it allocates the following nodes needed for every
233 * The start block containing a start node and Proj nodes for it's
234 five results (X, M, P, P, T).
235 * The end block containing an end node. This block is not matured
236 after executing new_ir_graph as predecessors need to be added to it.
237 (Maturing a block means fixing it's number of predecessors.)
238 * The current block, which is empty and also not matured.
240 Further it enters the global store into the datastructure of the start
241 block that contanis all valid values in this block (set_store()). This
242 datastructure is used to build the Phi nodes and removed after completion
244 There is no path from end to start in the graph after calling ir_graph.
247 PROCEDURE TO CONSTRUCT AN IR GRAPH
248 ==================================
250 This library supplies several interfaces to construct a FIRM graph for
252 * A "comfortable" interface generating SSA automatically. Automatically
253 computed predecessors of nodes need not be specified in the constructors.
254 (new_<Node> constructurs and a set of additional routines.)
255 * A less comfortable interface where all predecessors except the block
256 an operation belongs to need to be specified. SSA must be constructed
257 by hand. (new_<Node> constructors and switch_block()). This interface
258 is called "block oriented". It automatically calles the local optimizations
260 * An even less comfortable interface where the block needs to be specified
261 explicitly. This is called the "raw" interface. (new_r_<Node>
262 constructors). These nodes are not optimized.
264 To use the functionality of the comfortable interface correctly the Front
265 End needs to follow certain protocols. This is explained in the following.
266 To build a correct IR with the other interfaces study the semantics of
267 the firm node (See tech-reprot UKA 1999-44). For the construction of
268 types and entities see the documentation in those modules.
270 First the Frontend needs to decide which variables and values used in
271 a procedure can be represented by dataflow edges. These are variables
272 that need not be saved to memory as they cause no side effects visible
273 out of the procedure. In general these are all compiler generated
274 variables and simple local variables of the procedure as integers,
275 reals and pointers. The frontend has to count and number these variables.
277 First an ir_graph needs to be constructed with new_ir_graph. The
278 constructor gets the number of local variables. The graph is hold in the
281 Now the construction of the procedure can start. Several basic blocks can
282 be constructed in parallel, but the code within each block needs to
283 be constructed (almost) in program order.
285 A global variable holds the current basic block. All (non block) nodes
286 generated are added to this block. The current block can be set with
287 switch_block(block). If several blocks are constructed in parallel block
288 switches need to be performed constantly.
290 To generate a Block node (with the comfortable interface) it's predecessor
291 control flow nodes need not be known. In case of cyclic control flow these
292 can not be known when the block is constructed. With add_in_edge(block,
293 cfnode) predecessors can be added to the block. If all predecessors are
294 added to the block mature_block(b) needs to be called. Calling mature_block
295 early improves the efficiency of the Phi node construction algorithm.
296 But if several blocks are constructed at once, mature_block must only
297 be called after performing all set_values and set_stores in the block!
298 (See documentation of new_immBlock constructor.)
300 The constructors of arithmetic nodes require that their predecessors
301 are mentioned. Sometimes these are available in the Frontend as the
302 predecessors have just been generated by the frontend. If they are local
303 values the predecessors can be obtained from the library with a call to
304 get_value(local_val_nr). (local_val_nr needs to be administered by
305 the Frontend.) A call to get_value triggers the generation of Phi nodes.
306 If an arithmetic operation produces a local value this value needs to be
307 passed to the library by set_value(node, local_val_nr).
308 In straight line code these two operations just remember and return the
309 pointer to nodes producing the value. If the value passes block boundaries
310 Phi nodes can be inserted.
311 Similar routines exist to manage the Memory operands: set_store and
314 Several nodes produce more than one result. An example is the Div node.
315 Such nodes return tuples of values. From these individual values can be
316 extracted by proj nodes.
318 The following example illustrates the construction of a simple basic block
319 with two predecessors stored in variables cf_pred1 and cf_pred2, containing
322 and finally jumping to an other block. The variable a got the local_val_nr
325 ir_node *this_block, *cf_pred1, *cf_pred2, *a_val, *mem, *div, *res, *cf_op;
327 this_block = new_immBlock();
328 add_in_edge(this_block, cf_pred1);
329 add_in_edge(this_block, cf_pred2);
330 mature_block(this_block);
331 a_val = get_value(17, mode_I);
333 div = new_Div(mem, a_val, a_val);
334 mem = new_Proj(div, mode_M, 0); * for the numbers for Proj see docu *
335 res = new_Proj(div, mode_I, 2);
340 For further information look at the documentation of the nodes and
341 constructors and at the paragraph COPING WITH DATA OBJECTS at the
342 end of this documentation.
344 The comfortable interface contains the following routines further explained
347 ir_node *new_immBlock (void);
348 ir_node *new_Start (void);
349 ir_node *new_End (void);
350 ir_node *new_Jmp (void);
351 ir_node *new_Cond (ir_node *c);
352 ir_node *new_Return (ir_node *store, int arity, ir_node **in);
353 ir_node *new_Raise (ir_node *store, ir_node *obj);
354 ir_node *new_Const (ir_mode *mode, tarval *con);
355 ir_node *new_SymConst (type_or_id *value, symconst_kind kind);
356 ir_node *new_simpleSel (ir_node *store, ir_node *objptr, entity *ent);
357 ir_node *new_Sel (ir_node *store, ir_node *objptr, int arity,
358 ir_node **in, entity *ent);
359 ir_node *new_Call (ir_node *store, ir_node *callee, int arity,
360 ir_node **in, type_method *type);
361 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode);
362 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode);
363 ir_node *new_Minus (ir_node *op, ir_mode *mode);
364 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode);
365 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2);
366 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2);
367 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2);
368 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2);
369 ir_node *new_Abs (ir_node *op, ir_mode *mode);
370 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode);
371 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode);
372 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode);
373 ir_node *new_Not (ir_node *op, ir_mode *mode);
374 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode);
375 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode);
376 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode);
377 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode);
378 ir_node *new_Cmp (ir_node *op1, ir_node *op2);
379 ir_node *new_Conv (ir_node *op, ir_mode *mode);
380 ir_node *new_Load (ir_node *store, ir_node *addr);
381 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val);
382 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
384 ir_node *new_Free (ir_node *store, ir_node *ptr, ir_node *size,
386 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj);
388 void add_in_edge (ir_node *block, ir_node *jmp);
389 void mature_block (ir_node *block);
390 void switch_block (ir_node *target);
391 ir_node *get_value (int pos, ir_mode *mode);
392 void set_value (int pos, ir_node *value);
393 ir_node *get_store (void);
394 void set_store (ir_node *store);
397 IR_NODES AND CONSTRUCTORS FOR IR_NODES
398 =======================================
400 All ir_nodes are defined by a common data structure. They are distinguished
401 by their opcode and differ in the number of their attributes.
403 The constructor for the block node sets current_block to itself.
404 Const nodes are always added to the start block.
405 All other constructors add the created node to the current_block.
406 swich_block(block) allows to set the current block to block.
408 Watch for my inconsistent use of input and predecessor (dataflow view)
409 and `the node points to' (implementation view).
411 The following description of the nodes lists four properties them if these
413 - the parameters to the constructor
414 - the inputs of the Firm node
415 - the outputs of the Firm node
416 - attributes to the node
421 ir_node *new_immBlock (void)
422 ----------------------------
424 Creates a new block. Sets current_block to itself. When a new block is
425 created it cannot be known how many predecessors this block will have in the
426 control flow graph. Therefore the list of inputs can not be fixed at
427 creation. Predecessors can be added with add_in_edge (block, control flow
428 operation). With every added predecessor the number of inputs to Phi nodes
431 The block can be completed by mature_block(block) if all predecessors are
432 known. If several blocks are built at once, mature_block can only be called
433 after set_value has been called for all values that are life at the end
434 of the block. This is necessary so that Phi nodes created by mature_block
435 get the right predecessors in case of cyclic dependencies. If all set_values
436 of this block are called after maturing it and before calling get_value
437 in some block that is control flow dependent on this block, the construction
440 Example for faulty ir construction: (draw the graph on a paper and you'll
443 block_before_loop = new_block();
445 mature_block(block_before_loop);
446 before2header = new_Jmp;
448 loop_header = new_block ();
449 header2body - new_Jmp();
451 loop_body = new_block ();
452 body2header = new_Jmp();
454 add_in_edge(loop_header, before2header);
455 add_in_edge(loop_header, body2header);
456 add_in_edge(loop_body, header2body);
458 mature_block(loop_header);
459 mature_block(loop_body);
461 get_value(loop_body, x); // gets the Phi in loop_header
462 set_value(loop_header, x); // sets the value the above get_value should
465 Mature_block also fixes the number of inputs to the Phi nodes. Mature_block
466 should be called as early as possible, as afterwards the generation of Phi
467 nodes is more efficient.
470 There is an input for each control flow predecessor of the block.
471 The input points to an instruction producing an output of type X.
472 Possible predecessors: Start, Jmp, Cond, Raise or Return or any node
473 possibly causing an exception. (Often the real predecessors are Projs.)
475 Mode BB (R), all nodes belonging to this block should consume this output.
476 As they are strict (except Block and Phi node) it is a necessary condition
477 that the block node executed before any other node in this block executes.
479 block.matured Indicates whether the block is mature.
481 This attribute contains all local values valid in this
482 block. This is needed to build the Phi nodes and removed
483 if the graph is complete. This field is used by the
484 internal construction algorithm and should not be accessed
488 ir_node *new_Block (int arity, ir_node **in)
489 --------------------------------------------
491 Creates a new Block with the given list of predecessors. This block
495 CONTROL FLOW OPERATIONS
496 -----------------------
498 In each block there must be exactly one of the control flow
499 operations Start, End, Jmp, Cond, Return or Raise. The output of a
500 control flow operation points to the block to be executed next.
502 ir_node *new_Start (void)
503 -------------------------
505 Creates a start node. Not actually needed public. There is only one such
506 node in each procedure which is automatically created by new_ir_graph.
509 No inputs except the block it belogns to.
511 A tuple of 4 (5, 6) distinct values. These are labeled by the following
512 projection numbers (pns_number):
514 mode X, points to the first block to be executed.
516 mode M, the global store
517 * pns_frame_base mode P, a pointer to the base of the procedures
519 * pns_globals mode P, a pointer to the part of the memory containing
521 * pns_args mode T, a tuple containing all arguments of the procedure.
524 ir_node *new_End (void)
525 -----------------------
527 Creates an end node. Not actually needed public. There is only one such
528 node in each procedure which is automatically created by new_ir_graph.
531 No inputs except the block it belongs to.
535 ir_node *new_Jmp (void)
536 -----------------------
541 The block the node belongs to
543 Control flow to the next block.
545 ir_node *new_Cond (ir_node *c)
546 ------------------------------
548 Creates a Cond node. There are two versions of this node.
554 A tuple of two control flows. The first is taken if the input is
555 false, the second if it is true.
559 A value of mode I_u. (i)
561 A tuple of n control flows. If the Cond's input is i, control
562 flow will procede along output i. If the input is >= n control
563 flow proceeds along output n.
565 ir_node *new_Return (in_node *store, int arity, ir_node **in)
566 -------------------------------------------------------------
568 The return node has as inputs the results of the procedure. It
569 passes the control flow to the end_block.
575 Control flow to the end block.
577 ir_node *new_Raise (ir_node *store, ir_node *obj)
578 -------------------------------------------------
580 Raises an exception. Unconditional change of control flow. Writes
581 an explicit Except variable to memory to pass it to the exception
582 handler. See TechReport 1999-14, chapter Exceptions.
586 A pointer to the Except variable.
588 A tuple of control flow and the changed memory state. The control flow
589 points to the exception handler if it is definied in this procedure,
590 else it points to the end_block.
596 ir_node *new_Const (ir_mode *mode, tarval *con)
597 -----------------------------------------------
599 Creates a constant in the constant table and adds a Const node
600 returning this value to the start block.
603 *mode The mode of the constant.
604 *con Points to an entry in the constant table.
605 This pointer is added to the attributes of
606 the node (self->attr.con)
608 No inputs except the block it belogns to.
612 attr.con A tarval* pointer to the proper entry in the constant
615 ir_node *new_SymConst (type *type, symconst_kind kind)
616 ------------------------------------------------------------
618 There are three kinds of symbolic constants:
619 type_tag The symbolic constant represents a type tag.
620 size The symbolic constant represents the size of a class.
621 link_info Information for the linker, e.g. the name of a global
625 kind The kind of the symbolic constant: type_tag, size or link_info.
626 *type_or_id Points to the type the tag stands for or to the type
627 whose size is represented by the constant or to an ident
628 representing the linkage info.
631 No inputs except the block it belogns to.
633 An unsigned integer (I_u) or a pointer (P).
636 attr.i.num The symconst_kind, i.e. one of
640 If the attr.i.num is type_tag or size, the node contains an attribute
641 attr.i.*type, a pointer to a type_class. The mode of the node is mode_i.
642 if it is linkage_ptr_info it contains
643 attr.i.*ptrinfo, an ident holding information for the linker. The mode
644 of the node is mode_p.
649 ir_node *new_simpleSel (ir_node *store, ir_node *frame, entity *sel)
650 --------------------------------------------------------------------
653 Selects an entity from a compound type. This entity can be a field or
657 *store The memory in which the object the entity should be selected
659 *frame The pointer to the object.
660 *sel The entity to select.
663 The memory containing the object.
664 A pointer to the object.
667 A pointer to the selected entity.
669 attr.sel Pointer to the entity
672 ir_node *new_Sel (ir_node *store, ir_node *frame, int arity, ir_node **in,
673 --------------------------------------------------------------------------
677 Selects a field from an array type. The entity has as owner the array, as
678 type the arrays element type. The indexes to access an array element are
682 *store The memory in which the object the entity should be selected from
684 *frame The pointer to the object.
685 *arity number of array indexes.
686 *in array with index inputs to the node.
687 *sel The entity to select.
690 The memory containing the object.
691 A pointer to the object.
692 As much unsigned integer as there are array expressions.
694 A pointer to the selected entity.
696 attr.sel Pointer to the entity
698 The constructors new_Sel and new_simpleSel generate the same ir nodes.
699 simpleSel just sets the arity of the index inputs to zero.
702 ARITHMETIC OPERATIONS
703 ---------------------
705 ir_node *new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
706 ----------------------------------------------------------------------------
710 Creates a procedure call.
713 *store The actual store.
714 *callee A pointer to the called procedure.
715 arity The number of procedure parameters.
716 **in An array with the pointers to the parameters.
717 The constructor copies this array.
718 *type Type information of the procedure called.
721 The store, the callee and the parameters.
723 A tuple containing the eventually changed store and the procedure
726 attr.call Contains the type information for the procedure.
728 ir_node *new_Add (ir_node *op1, ir_node *op2, ir_mode *mode)
729 ------------------------------------------------------------
733 ir_node *new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode)
734 ------------------------------------------------------------
738 ir_node *new_Minus (ir_node *op, ir_mode *mode)
739 -----------------------------------------------
741 This constructor is for unary Minus operations on floating point
742 values. Such a Minus can trap if it is implemented as a Sub from
743 zero due to rounding errors.
745 ir_node *new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode)
746 ------------------------------------------------------------
750 ir_node *new_Quot (ir_node *memop, ir_node *op1, ir_node *op2)
751 --------------------------------------------------------------
753 Quot performs exact division of floating point numbers. It's mode
754 is Tuple, the mode of the result must be annotated to the Proj
755 that extracts the result of the arithmetic operations.
758 The store needed to model exceptions and the two operands.
760 A tuple contaning a memory and a execution for modeling exceptions
761 and the result of the arithmetic operation.
763 ir_node *new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2)
764 ----------------------------------------------------------------
766 Performs Div and Mod on interger values.
769 A tuple contaning a memory and a execution for modeling exceptions
770 and the two result of the arithmetic operations.
772 ir_node *new_Div (ir_node *memop, ir_node *op1, ir_node *op2)
773 -------------------------------------------------------------
777 ir_node *new_Mod (ir_node *memop, ir_node *op1, ir_node *op2)
778 -------------------------------------------------------------
782 ir_node *new_Abs (ir_node *op, ir_mode *mode)
783 ---------------------------------------------
787 ir_node *new_And (ir_node *op1, ir_node *op2, ir_mode *mode)
788 ------------------------------------------------------------
792 ir_node *new_Or (ir_node *op1, ir_node *op2, ir_mode *mode)
793 -----------------------------------------------------------
797 ir_node *new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode)
798 ------------------------------------------------------------
802 ir_node *new_Not (ir_node *op, ir_mode *mode)
803 ---------------------------------------------
805 This node constructs a constant where all bits are set to one
806 and a Eor of this constant and the operator. This simulates a
809 ir_node *new_Shl (ir_node *op, ir_node *k, ir_mode *mode)
810 ---------------------------------------------------------
814 ir_node *new_Shr (ir_node *op, ir_node *k, ir_mode *mode)
815 ---------------------------------------------------------
817 Logic shift right, i.e., zero extended.
820 ir_node *new_Shrs (ir_node *op, ir_node *k, ir_mode *mode)
821 ----------------------------------------------------------
823 Arithmetic shift right, i.e., sign extended.
825 ir_node *new_Rot (ir_node *op, ir_node *k, ir_mode *mode)
826 ---------------------------------------------------------
828 Rotates the operand to the (right??) by k bits.
830 ir_node *new_Conv (ir_node *op, ir_mode *mode)
831 ---------------------------------------------
833 Mode conversion. For allowed conversions see UKA Tech Report
836 ir_node *new_Cmp (ir_node *op1, ir_node *op2)
837 ---------------------------------------------
840 The two values to be compared.
842 A 16-tuple containing the results of the 16 different comparisons.
843 The following is a list giving the comparisons and a projection
844 number (pnc_number) to use in Proj nodes to extract the proper result.
852 Leg less, equal or greater = ordered
854 Ue unordered or equal
856 Ule unordered, less or equal
857 Ug unordered or greater
858 Uge unordered, greater or equal
859 Ne unordered, less or greater = not equal
867 In general, Phi nodes are automaitcally inserted. In some cases, if
868 all predecessors of a block are known, an explicit Phi node constructor
869 is needed. E.g., to construct a FIRM graph for a statement as
872 ir_node *new_Phi (int arity, ir_node **in, ir_mode *mode)
873 ---------------------------------------------------------
875 Creates a Phi node. The in's order has to correspond to the order
876 of in's of current_block. This is not checked by the library!
879 arity number of predecessors
880 **in array with predecessors
881 *mode The mode of it's inputs and output.
883 A Phi node has as many inputs as the block it belongs to.
884 Each input points to a definition of the same value on a
885 different path in the control flow.
887 The definition valid in this block.
890 OPERATIONS TO MANAGE MEMORY EXPLICITLY
891 --------------------------------------
893 ir_node *new_Load (ir_node *store, ir_node *addr)
894 ----------------------------------------------------------------
896 The Load operation reads a value from memory.
899 *store The current memory.
900 *addr A pointer to the variable to be read in this memory.
903 The memory and a pointer to a variable in this memory.
905 A tuple of the memory, a control flow to be taken in case of
906 an exception and the loaded value.
908 ir_node *new_Store (ir_node *store, ir_node *addr, ir_node *val)
909 ----------------------------------------------------------------
911 The Store operation writes a value to a variable in memory.
914 The memory, a pointer to a variable in this memory and the value
915 to write to this variable.
917 A tuple of the changed memory and a control flow to be taken in
918 case of an exception.
920 ir_node *new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
921 --------------------------------------------------------------------
925 The Alloc node allocates a new variable. It can be specified whether the
926 variable should be allocated to the stack or to the heap.
929 *store The memory which shall contain the new variable.
930 ** *size The number of bytes to allocate. Old. **
931 *size We decided that the size easily can be derived from the type.
932 This field is for allocating arrays, i.e., it gives the multiple
933 of the size of alloc_type to allocate memory for.
934 *alloc_type The type of the allocated variable.
935 where Where to allocate the variable, either heap_alloc or stack_alloc.
938 A memory and an unsigned integer.
940 A tuple of the changed memory, a control flow to be taken in
941 case of an exception and the pointer to the new variable.
943 a.where Indicates where the variable is allocated.
944 a.*type A pointer to the class the allocated data object
947 ir_node *new_Free (ir_node *store, ir_node *ptr, type *free_type)
948 ------------------------------------------------------------------
950 The Free node frees memory of the given variable.
953 *store The memory which shall contain the new variable.
954 *ptr The pointer to the object to free.
955 *size The number of objects of type free_type to free in a sequence.
956 *free_type The type of the freed variable.
959 A memory, a pointer and an unsigned integer.
963 f.*type A pointer to the type information of the freed data object.
967 ir_node *new_Sync (int arity, ir_node **in)
968 -------------------------------------------
970 The Sync operation unifies several partial memory blocks. These blocks
971 have to be pairwise disjunct or the values in common locations have to
972 be identical. This operation allows to specify all operations that eventually
973 need several partial memory blocks as input with a single entrance by
974 unifying the memories with a preceding Sync operation.
977 arity The number of memories to syncronize.
978 **in An array of pointers to nodes that produce an output of
989 ir_node *new_Bad (void)
990 -----------------------
992 Returns the unique Bad node current_ir_graph->bad.
993 This node is used to express results of dead code elimination.
995 ir_node *new_Proj (ir_node *arg, ir_mode *mode, long proj)
996 ----------------------------------------------------------
998 Selects one entry of a tuple. This is a hidden `fat edge'.
1001 *arg A node producing a tuple.
1002 *mode The mode of the value to project.
1003 proj The position of the value in the tuple.
1009 ir_node *new_Tuple (int arity, ir_node **in)
1010 --------------------------------------------
1012 Builds a Tuple from single values. This is needed to implement
1013 optimizations that remove a node that produced a tuple. The node can be
1014 replaced by the Tuple operation so that the following Proj nodes have not to
1015 be changed. (They are hard to find due to the implementation with pointers
1016 in only one direction.) The Tuple node is smaller than any other
1017 node, so that a node can be changed into a Tuple by just changing it's
1018 opcode and giving it a new in array.
1021 arity The number of tuple elements.
1022 **in An array containing pointers to the nodes producing the
1025 ir_node *new_Id (ir_node *val, ir_mode *mode)
1026 ---------------------------------------------
1028 The single output of the Id operation is it's input. Also needed
1032 COPING WITH DATA OBJECTS
1033 ========================
1035 Two kinds of data objects have to be distinguished for generating
1036 FIRM. First there are local variables other than arrays that are
1037 known to be alias free. Second there are all other data objects.
1038 For the first a common SSA representation is built, the second
1039 are modeled by saving them to memory. The memory is treated as
1040 a single local variable, the alias problem is hidden in the
1041 content of this variable.
1043 All values known in a Block are listed in the block's attribute,
1044 block.**graph_arr which is used to automatically insert Phi nodes.
1045 The following two funcions can be used to add a newly computed value
1046 to the array, or to get the producer of a value, i.e., the current
1049 inline void set_value (int pos, ir_node *value)
1050 -----------------------------------------------
1052 Has to be called for every assignment to a local variable. It
1053 adds the value to the array of used values at position pos. Pos
1054 has to be a unique identifier for an entry in the procedure's
1055 definition table. It can be used to access the value again.
1057 ir_node *get_value (int pos, ir_mode *mode)
1058 -------------------------------------------
1060 Returns the node defining the value referred to by pos. If the
1061 value is not defined in this block a Phi node is generated and
1062 all definitions reaching this Phi node are collected. It can
1063 happen that the algorithm allocates an unnecessary Phi node,
1064 e.g. if there is only one definition of this value, but this
1065 definition reaches the currend block on several different
1066 paths. This Phi node will be eliminated if optimizations are
1067 turned on right after it's creation.
1070 There are two special routines for the global store:
1072 inline void set_store (ir_node *store)
1073 --------------------------------------
1075 Adds the store to the array of known values at a reserved
1078 inline ir_node *get_store (void)
1079 --------------------------------
1081 Returns the node defining the actual store.
1089 # include "common.h"
1090 # include "irgraph.h"
1091 # include "irnode.h"
1092 # include "irmode.h"
1093 # include "entity.h"
1097 /***************************************************************************/
1098 /* The raw interface */
1099 /***************************************************************************/
1101 /* Constructs a Block with a fixed number of predecessors.
1102 Does not set current_block. Can not be used with automatic
1103 Phi node construction. */
1104 ir_node *new_r_Block (ir_graph *irg, int arity, ir_node **in);
1105 ir_node *new_r_Start (ir_graph *irg, ir_node *block);
1106 ir_node *new_r_End (ir_graph *irg, ir_node *block);
1107 ir_node *new_r_Jmp (ir_graph *irg, ir_node *block);
1108 ir_node *new_r_Cond (ir_graph *irg, ir_node *block, ir_node *c);
1109 ir_node *new_r_Return (ir_graph *irg, ir_node *block,
1110 ir_node *store, int arity, ir_node **in);
1111 ir_node *new_r_Raise (ir_graph *irg, ir_node *block,
1112 ir_node *store, ir_node *obj);
1113 ir_node *new_r_Const (ir_graph *irg, ir_node *block,
1114 ir_mode *mode, tarval *con);
1115 ir_node *new_r_SymConst (ir_graph *irg, ir_node *block,
1116 type_or_id_p value, symconst_kind symkind);
1117 ir_node *new_r_Sel (ir_graph *irg, ir_node *block, ir_node *store,
1118 ir_node *objptr, int n_index, ir_node **index,
1120 ir_node *new_r_Call (ir_graph *irg, ir_node *block, ir_node *store,
1121 ir_node *callee, int arity, ir_node **in,
1123 ir_node *new_r_Add (ir_graph *irg, ir_node *block,
1124 ir_node *op1, ir_node *op2, ir_mode *mode);
1125 ir_node *new_r_Sub (ir_graph *irg, ir_node *block,
1126 ir_node *op1, ir_node *op2, ir_mode *mode);
1127 ir_node *new_r_Minus (ir_graph *irg, ir_node *block,
1128 ir_node *op, ir_mode *mode);
1129 ir_node *new_r_Mul (ir_graph *irg, ir_node *block,
1130 ir_node *op1, ir_node *op2, ir_mode *mode);
1131 ir_node *new_r_Quot (ir_graph *irg, ir_node *block,
1132 ir_node *memop, ir_node *op1, ir_node *op2);
1133 ir_node *new_r_DivMod (ir_graph *irg, ir_node *block,
1134 ir_node *memop, ir_node *op1, ir_node *op2);
1135 ir_node *new_r_Div (ir_graph *irg, ir_node *block,
1136 ir_node *memop, ir_node *op1, ir_node *op2);
1137 ir_node *new_r_Mod (ir_graph *irg, ir_node *block,
1138 ir_node *memop, ir_node *op1, ir_node *op2);
1139 ir_node *new_r_Abs (ir_graph *irg, ir_node *block,
1140 ir_node *op, ir_mode *mode);
1141 ir_node *new_r_And (ir_graph *irg, ir_node *block,
1142 ir_node *op1, ir_node *op2, ir_mode *mode);
1143 ir_node *new_r_Or (ir_graph *irg, ir_node *block,
1144 ir_node *op1, ir_node *op2, ir_mode *mode);
1145 ir_node *new_r_Eor (ir_graph *irg, ir_node *block,
1146 ir_node *op1, ir_node *op2, ir_mode *mode);
1147 ir_node *new_r_Not (ir_graph *irg, ir_node *block,
1148 ir_node *op, ir_mode *mode);
1149 ir_node *new_r_Cmp (ir_graph *irg, ir_node *block,
1150 ir_node *op1, ir_node *op2);
1151 ir_node *new_r_Shl (ir_graph *irg, ir_node *block,
1152 ir_node *op, ir_node *k, ir_mode *mode);
1153 ir_node *new_r_Shr (ir_graph *irg, ir_node *block,
1154 ir_node *op, ir_node *k, ir_mode *mode);
1155 ir_node *new_r_Shrs (ir_graph *irg, ir_node *block,
1156 ir_node *op, ir_node *k, ir_mode *mode);
1157 ir_node *new_r_Rot (ir_graph *irg, ir_node *block,
1158 ir_node *op, ir_node *k, ir_mode *mode);
1159 ir_node *new_r_Conv (ir_graph *irg, ir_node *block,
1160 ir_node *op, ir_mode *mode);
1161 ir_node *new_r_Phi (ir_graph *irg, ir_node *block, int arity,
1162 ir_node **in, ir_mode *mode);
1163 ir_node *new_r_Load (ir_graph *irg, ir_node *block,
1164 ir_node *store, ir_node *adr);
1165 ir_node *new_r_Store (ir_graph *irg, ir_node *block,
1166 ir_node *store, ir_node *adr, ir_node *val);
1167 ir_node *new_r_Alloc (ir_graph *irg, ir_node *block, ir_node *store,
1168 ir_node *size, type *alloc_type, where_alloc where);
1169 ir_node *new_r_Free (ir_graph *irg, ir_node *block, ir_node *store,
1170 ir_node *ptr, ir_node *size, type *free_type);
1171 ir_node *new_r_Sync (ir_graph *irg, ir_node *block, int arity, ir_node **in);
1172 ir_node *new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg,
1173 ir_mode *mode, long proj);
1174 ir_node *new_r_Tuple (ir_graph *irg, ir_node *block,
1175 int arity, ir_node **in);
1176 ir_node *new_r_Id (ir_graph *irg, ir_node *block,
1177 ir_node *val, ir_mode *mode);
1178 ir_node *new_r_Bad ();
1181 /*************************************************************************/
1182 /* The block oriented interface */
1183 /*************************************************************************/
1185 /* Sets the current block in which the following constructors place the
1186 nodes they construct. */
1187 void switch_block (ir_node *target);
1189 /* Constructs a Block with a fixed number of predecessors.
1190 Does set current_block. Can be used with automatic Phi
1191 node construction. */
1192 ir_node *new_Block(int arity, ir_node **in);
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_p 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 */
1243 /***********************************************************************/
1245 /** Block construction **/
1246 /* immature Block without predecessors */
1247 ir_node *new_immBlock (void);
1249 /* Add a control flow edge to an immature block. */
1250 void add_in_edge (ir_node *immblock, ir_node *jmp);
1252 /* fixes the number of predecessors of a block. */
1253 void mature_block (ir_node *block);
1255 /** Parameter administration **/
1256 /* Read a value from the array with the local variables. Use this
1257 function to obtain the last definition of the value associated with
1258 pos. Pos may not exceed the value passed as n_loc to new_ir_graph. */
1259 ir_node *get_value (int pos, ir_mode *mode);
1261 /* Write a value in the array with the local variables. Use this function
1262 to remember a new definition of the value associated with pos. Pos may
1263 not exceed the value passed as n_loc to new_ir_graph. */
1264 void set_value (int pos, ir_node *value);
1267 Use this function to get the most recent version of the store (type M).
1268 Internally it does the same as get_value. */
1269 ir_node *get_store (void);
1271 /* Write a store. */
1272 void set_store (ir_node *store);
1274 /***********************************************************************/
1275 /* initialize ir construction */
1276 /***********************************************************************/
1277 void init_cons (void);
1280 # endif /* _IRCONS_H_ */