1 /* Copyright (C) 1998 - 2000 by Universitaet Karlsruhe
2 ** All rights reserved.
4 ** Authors: Martin Trapp, Christian Schaefer
6 ** ircons.c: basic and more detailed irnode constructors
7 ** store, block and parameter administration.
8 ** Adapted to extended FIRM nodes (exceptions...) and commented
9 ** by Goetz Lindenmaier
16 # include "irgraph_t.h"
17 # include "irnode_t.h"
18 # include "irmode_t.h"
26 /* memset belongs to string.h */
29 #if USE_EXPICIT_PHI_IN_STACK
30 /* A stack needed for the automatic Phi node construction in constructor
31 Phi_in. Redefinition in irgraph.c!! */
36 typedef struct Phi_in_stack Phi_in_stack;
39 /*** ******************************************** */
40 /** privat interfaces, for professional use only */
42 /* Constructs a Block with a fixed number of predecessors.
43 Does not set current_block. Can not be used with automatic
44 Phi node construction. */
46 new_r_Block (ir_graph *irg, int arity, ir_node **in)
50 res = new_ir_node (irg, NULL, op_Block, mode_R, arity, in);
51 set_Block_matured(res, 1);
52 set_Block_block_visited(res, 0);
59 new_r_Start (ir_graph *irg, ir_node *block)
63 res = new_ir_node (irg, block, op_Start, mode_T, 0, NULL);
70 new_r_End (ir_graph *irg, ir_node *block)
74 res = new_ir_node (irg, block, op_End, mode_X, -1, NULL);
80 /* Creates a Phi node with all predecessors. Calling this constructor
81 is only allowed if the corresponding block is mature. */
83 new_r_Phi (ir_graph *irg, ir_node *block, int arity, ir_node **in, ir_mode *mode)
87 assert( get_Block_matured(block) );
88 assert( get_irn_arity(block) == arity );
90 res = new_ir_node (irg, block, op_Phi, mode, arity, in);
98 new_r_Const (ir_graph *irg, ir_node *block, ir_mode *mode, tarval *con)
101 res = new_ir_node (irg, block, op_Const, mode, 0, NULL);
103 res = optimize (res);
107 res = local_optimize_newby (res);
114 new_r_Id (ir_graph *irg, ir_node *block, ir_node *val, ir_mode *mode)
116 ir_node *in[1] = {val};
118 res = new_ir_node (irg, block, op_Id, mode, 1, in);
119 res = optimize (res);
125 new_r_Proj (ir_graph *irg, ir_node *block, ir_node *arg, ir_mode *mode,
128 ir_node *in[1] = {arg};
130 res = new_ir_node (irg, block, op_Proj, mode, 1, in);
131 res->attr.proj = proj;
134 assert(get_Proj_pred(res));
135 assert(get_nodes_Block(get_Proj_pred(res)));
137 res = optimize (res);
145 new_r_defaultProj (ir_graph *irg, ir_node *block, ir_node *arg,
149 assert((arg->op==op_Cond) && (get_irn_mode(arg->in[1]) == mode_I));
150 arg->attr.c.kind = fragmentary;
151 arg->attr.c.default_proj = max_proj;
152 res = new_r_Proj (irg, block, arg, mode_X, max_proj);
157 new_r_Conv (ir_graph *irg, ir_node *block, ir_node *op, ir_mode *mode)
159 ir_node *in[1] = {op};
161 res = new_ir_node (irg, block, op_Conv, mode, 1, in);
162 res = optimize (res);
169 new_r_Tuple (ir_graph *irg, ir_node *block, int arity, ir_node **in)
173 res = new_ir_node (irg, block, op_Tuple, mode_T, arity, in);
174 res = optimize (res);
180 new_r_Add (ir_graph *irg, ir_node *block,
181 ir_node *op1, ir_node *op2, ir_mode *mode)
183 ir_node *in[2] = {op1, op2};
185 res = new_ir_node (irg, block, op_Add, mode, 2, in);
186 res = optimize (res);
192 new_r_Sub (ir_graph *irg, ir_node *block,
193 ir_node *op1, ir_node *op2, ir_mode *mode)
195 ir_node *in[2] = {op1, op2};
197 res = new_ir_node (irg, block, op_Sub, mode, 2, in);
198 res = optimize (res);
204 new_r_Minus (ir_graph *irg, ir_node *block,
205 ir_node *op, ir_mode *mode)
207 ir_node *in[1] = {op};
209 res = new_ir_node (irg, block, op_Minus, mode, 1, in);
210 res = optimize (res);
216 new_r_Mul (ir_graph *irg, ir_node *block,
217 ir_node *op1, ir_node *op2, ir_mode *mode)
219 ir_node *in[2] = {op1, op2};
221 res = new_ir_node (irg, block, op_Mul, mode, 2, in);
222 res = optimize (res);
228 new_r_Quot (ir_graph *irg, ir_node *block,
229 ir_node *memop, ir_node *op1, ir_node *op2)
231 ir_node *in[3] = {memop, op1, op2};
233 res = new_ir_node (irg, block, op_Quot, mode_T, 3, in);
234 res = optimize (res);
240 new_r_DivMod (ir_graph *irg, ir_node *block,
241 ir_node *memop, ir_node *op1, ir_node *op2)
243 ir_node *in[3] = {memop, op1, op2};
245 res = new_ir_node (irg, block, op_DivMod, mode_T, 3, in);
246 res = optimize (res);
252 new_r_Div (ir_graph *irg, ir_node *block,
253 ir_node *memop, ir_node *op1, ir_node *op2)
255 ir_node *in[3] = {memop, op1, op2};
257 res = new_ir_node (irg, block, op_Div, mode_T, 3, in);
258 res = optimize (res);
264 new_r_Mod (ir_graph *irg, ir_node *block,
265 ir_node *memop, ir_node *op1, ir_node *op2)
267 ir_node *in[3] = {memop, op1, op2};
269 res = new_ir_node (irg, block, op_Mod, mode_T, 3, in);
270 res = optimize (res);
276 new_r_And (ir_graph *irg, ir_node *block,
277 ir_node *op1, ir_node *op2, ir_mode *mode)
279 ir_node *in[2] = {op1, op2};
281 res = new_ir_node (irg, block, op_And, mode, 2, in);
282 res = optimize (res);
288 new_r_Or (ir_graph *irg, ir_node *block,
289 ir_node *op1, ir_node *op2, ir_mode *mode)
291 ir_node *in[2] = {op1, op2};
293 res = new_ir_node (irg, block, op_Or, mode, 2, in);
294 res = optimize (res);
300 new_r_Eor (ir_graph *irg, ir_node *block,
301 ir_node *op1, ir_node *op2, ir_mode *mode)
303 ir_node *in[2] = {op1, op2};
305 res = new_ir_node (irg, block, op_Eor, mode, 2, in);
306 res = optimize (res);
312 new_r_Not (ir_graph *irg, ir_node *block,
313 ir_node *op, ir_mode *mode)
315 ir_node *in[1] = {op};
317 res = new_ir_node (irg, block, op_Not, mode, 1, in);
318 res = optimize (res);
324 new_r_Shl (ir_graph *irg, ir_node *block,
325 ir_node *op, ir_node *k, ir_mode *mode)
327 ir_node *in[2] = {op, k};
329 res = new_ir_node (irg, block, op_Shl, mode, 2, in);
330 res = optimize (res);
336 new_r_Shr (ir_graph *irg, ir_node *block,
337 ir_node *op, ir_node *k, ir_mode *mode)
339 ir_node *in[2] = {op, k};
341 res = new_ir_node (irg, block, op_Shr, mode, 2, in);
342 res = optimize (res);
348 new_r_Shrs (ir_graph *irg, ir_node *block,
349 ir_node *op, ir_node *k, ir_mode *mode)
351 ir_node *in[2] = {op, k};
353 res = new_ir_node (irg, block, op_Shrs, mode, 2, in);
354 res = optimize (res);
360 new_r_Rot (ir_graph *irg, ir_node *block,
361 ir_node *op, ir_node *k, ir_mode *mode)
363 ir_node *in[2] = {op, k};
365 res = new_ir_node (irg, block, op_Rot, mode, 2, in);
366 res = optimize (res);
372 new_r_Abs (ir_graph *irg, ir_node *block,
373 ir_node *op, ir_mode *mode)
375 ir_node *in[1] = {op};
377 res = new_ir_node (irg, block, op_Abs, mode, 1, in);
378 res = optimize (res);
384 new_r_Cmp (ir_graph *irg, ir_node *block,
385 ir_node *op1, ir_node *op2)
387 ir_node *in[2] = {op1, op2};
389 res = new_ir_node (irg, block, op_Cmp, mode_T, 2, in);
390 res = optimize (res);
396 new_r_Jmp (ir_graph *irg, ir_node *block)
400 res = new_ir_node (irg, block, op_Jmp, mode_X, 0, in);
401 res = optimize (res);
407 new_r_Cond (ir_graph *irg, ir_node *block, ir_node *c)
409 ir_node *in[1] = {c};
411 res = new_ir_node (irg, block, op_Cond, mode_T, 1, in);
412 res->attr.c.kind = dense;
413 res->attr.c.default_proj = 0;
414 res = optimize (res);
420 new_r_Call (ir_graph *irg, ir_node *block, ir_node *store,
421 ir_node *callee, int arity, ir_node **in, type *type)
428 NEW_ARR_A (ir_node *, r_in, r_arity);
431 memcpy (&r_in[2], in, sizeof (ir_node *) * arity);
433 res = new_ir_node (irg, block, op_Call, mode_T, r_arity, r_in);
435 assert(is_method_type(type));
436 set_Call_type(res, type);
437 res = optimize (res);
443 new_r_Return (ir_graph *irg, ir_node *block,
444 ir_node *store, int arity, ir_node **in)
451 NEW_ARR_A (ir_node *, r_in, r_arity);
453 memcpy (&r_in[1], in, sizeof (ir_node *) * arity);
454 res = new_ir_node (irg, block, op_Return, mode_X, r_arity, r_in);
455 res = optimize (res);
461 new_r_Raise (ir_graph *irg, ir_node *block, ir_node *store, ir_node *obj)
463 ir_node *in[2] = {store, obj};
465 res = new_ir_node (irg, block, op_Raise, mode_X, 2, in);
467 res = optimize (res);
473 new_r_Load (ir_graph *irg, ir_node *block,
474 ir_node *store, ir_node *adr)
476 ir_node *in[2] = {store, adr};
478 res = new_ir_node (irg, block, op_Load, mode_T, 2, in);
480 res = optimize (res);
486 new_r_Store (ir_graph *irg, ir_node *block,
487 ir_node *store, ir_node *adr, ir_node *val)
489 ir_node *in[3] = {store, adr, val};
491 res = new_ir_node (irg, block, op_Store, mode_T, 3, in);
493 res = optimize (res);
499 new_r_Alloc (ir_graph *irg, ir_node *block, ir_node *store,
500 ir_node *size, type *alloc_type, where_alloc where)
502 ir_node *in[2] = {store, size};
504 res = new_ir_node (irg, block, op_Alloc, mode_T, 2, in);
506 res->attr.a.where = where;
507 res->attr.a.type = alloc_type;
509 res = optimize (res);
515 new_r_Free (ir_graph *irg, ir_node *block, ir_node *store,
516 ir_node *ptr, ir_node *size, type *free_type)
518 ir_node *in[3] = {store, ptr, size};
520 res = new_ir_node (irg, block, op_Free, mode_T, 3, in);
522 res->attr.f = free_type;
524 res = optimize (res);
530 new_r_Sel (ir_graph *irg, ir_node *block, ir_node *store, ir_node *objptr,
531 int arity, ir_node **in, entity *ent)
538 NEW_ARR_A (ir_node *, r_in, r_arity);
541 memcpy (&r_in[2], in, sizeof (ir_node *) * arity);
542 res = new_ir_node (irg, block, op_Sel, mode_p, r_arity, r_in);
544 res->attr.s.ltyp = static_linkage;
545 res->attr.s.ent = ent;
547 res = optimize (res);
553 new_r_SymConst (ir_graph *irg, ir_node *block, type_or_id_p value,
554 symconst_kind symkind)
559 if (symkind == linkage_ptr_info)
563 res = new_ir_node (irg, block, op_SymConst, mode, 0, in);
565 res->attr.i.num = symkind;
566 if (symkind == linkage_ptr_info) {
567 res->attr.i.tori.ptrinfo = (ident *)value;
569 assert ( ( (symkind == type_tag)
570 || (symkind == size))
571 && (is_type(value)));
572 res->attr.i.tori.typ = (type *)value;
574 res = optimize (res);
580 new_r_Sync (ir_graph *irg, ir_node *block, int arity, ir_node **in)
584 res = new_ir_node (irg, block, op_Sync, mode_M, arity, in);
586 res = optimize (res);
594 return current_ir_graph->bad;
597 /** ********************/
598 /** public interfaces */
599 /** construction tools */
601 /****f* ircons/new_Start
604 * new_Start -- create a new Start node in the current block
607 * s = new_Start(void);
608 * ir_node* new_Start(void);
611 * s - pointer to the created Start node
620 res = new_ir_node (current_ir_graph, current_ir_graph->current_block,
621 op_Start, mode_T, 0, NULL);
623 res = optimize (res);
633 res = new_ir_node (current_ir_graph, current_ir_graph->current_block,
634 op_End, mode_X, -1, NULL);
636 res = optimize (res);
642 /* Constructs a Block with a fixed number of predecessors.
643 Does set current_block. Can be used with automatic Phi
644 node construction. */
646 new_Block (int arity, ir_node **in)
650 res = new_r_Block (current_ir_graph, arity, in);
651 current_ir_graph->current_block = res;
653 /* Create and initialize array for Phi-node construction. */
654 res->attr.block.graph_arr = NEW_ARR_D (ir_node *, current_ir_graph->obst,
655 current_ir_graph->n_loc);
656 memset(res->attr.block.graph_arr, 0, sizeof(ir_node *)*current_ir_graph->n_loc);
658 res = optimize (res);
664 /* ***********************************************************************/
665 /* Methods necessary for automatic Phi node creation */
667 ir_node *phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
668 ir_node *get_r_value_internal (ir_node *block, int pos, ir_mode *mode);
669 ir_node *new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode)
670 ir_node *new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode, ir_node **in, int ins)
672 Call Graph: ( A ---> B == A "calls" B)
674 get_value mature_block
682 get_r_value_internal |
686 new_r_Phi0 new_r_Phi_in
688 * *************************************************************************** */
690 /* Creates a Phi node with 0 predecessors */
692 new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode)
695 res = new_ir_node (irg, block, op_Phi, mode, 0, NULL);
700 /* There are two implementations of the Phi node construction. The first
701 is faster, but does not work for blocks with more than 2 predecessors.
702 The second works always but is slower and causes more unnecessary Phi
704 Select the implementations by the following preprocessor flag set in
706 #if USE_FAST_PHI_CONSTRUCTION
708 /* This is a stack used for allocating and deallocating nodes in
709 new_r_Phi_in. The original implementation used the obstack
710 to model this stack, now it is explicit. This reduces side effects.
712 #if USE_EXPICIT_PHI_IN_STACK
717 res = (Phi_in_stack *) malloc ( sizeof (Phi_in_stack));
719 res->stack = NEW_ARR_F (ir_node *, 1);
726 free_Phi_in_stack(Phi_in_stack *s) {
731 void free_to_Phi_in_stack(ir_node *phi) {
732 assert(get_irn_opcode(phi) == iro_Phi);
734 if (ARR_LEN(current_ir_graph->Phi_in_stack->stack) ==
735 current_ir_graph->Phi_in_stack->pos)
736 ARR_APP1 (ir_node *, current_ir_graph->Phi_in_stack->stack, phi);
738 current_ir_graph->Phi_in_stack->stack[current_ir_graph->Phi_in_stack->pos] = phi;
740 (current_ir_graph->Phi_in_stack->pos)++;
744 alloc_or_pop_from_Phi_in_stack(ir_graph *irg, ir_node *block, ir_mode *mode,
745 int arity, ir_node **in) {
747 ir_node **stack = current_ir_graph->Phi_in_stack->stack;
748 int pos = current_ir_graph->Phi_in_stack->pos;
752 /* We need to allocate a new node */
753 res = new_ir_node (irg, block, op_Phi, mode, arity, in);
755 /* reuse the old node and initialize it again. */
758 assert (res->kind == k_ir_node);
759 assert (res->op == op_Phi);
764 /* ???!!! How to free the old in array?? */
765 res->in = NEW_ARR_D (ir_node *, irg->obst, (arity+1));
767 memcpy (&res->in[1], in, sizeof (ir_node *) * arity);
769 (current_ir_graph->Phi_in_stack->pos)--;
773 #endif /* USE_EXPICIT_PHI_IN_STACK */
775 /* Creates a Phi node with a given, fixed array **in of predecessors.
776 If the Phi node is unnecessary, as the same value reaches the block
777 through all control flow paths, it is eliminated and the value
778 returned directly. This constructor is only intended for use in
779 the automatic Phi node generation triggered by get_value or mature.
780 The implementation is quite tricky and depends on the fact, that
781 the nodes are allocated on a stack:
782 The in array contains predecessors and NULLs. The NULLs appear,
783 if get_r_value_internal, that computed the predecessors, reached
784 the same block on two paths. In this case the same value reaches
785 this block on both paths, there is no definition in between. We need
786 not allocate a Phi where these path's merge, but we have to communicate
787 this fact to the caller. This happens by returning a pointer to the
788 node the caller _will_ allocate. (Yes, we predict the address. We can
789 do so because the nodes are allocated on the obstack.) The caller then
790 finds a pointer to itself and, when this routine is called again,
794 new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
795 ir_node **in, int ins)
798 ir_node *res, *known;
800 /* allocate a new node on the obstack.
801 This can return a node to which some of the pointers in the in-array
803 Attention: the constructor copies the in array, i.e., the later changes
804 to the array in this routine do not affect the constructed node! If
805 the in array contains NULLs, there will be missing predecessors in the
807 Is this a possible internal state of the Phi node generation? */
808 #if USE_EXPICIT_PHI_IN_STACK
809 res = known = alloc_or_pop_from_Phi_in_stack(irg, block, mode, ins, in);
811 res = known = new_ir_node (irg, block, op_Phi, mode, ins, in);
813 /* The in-array can contain NULLs. These were returned by
814 get_r_value_internal if it reached the same block/definition on a
816 The NULLs are replaced by the node itself to simplify the test in the
818 for (i=0; i < ins; ++i)
819 if (in[i] == NULL) in[i] = res;
821 /* This loop checks whether the Phi has more than one predecessor.
822 If so, it is a real Phi node and we break the loop. Else the
823 Phi node merges the same definition on several paths and therefore
825 for (i=0; i < ins; ++i)
827 if (in[i]==res || in[i]==known) continue;
835 /* i==ins: there is at most one predecessor, we don't need a phi node. */
837 #if USE_EXPICIT_PHI_IN_STACK
838 free_to_Phi_in_stack(res);
840 obstack_free (current_ir_graph->obst, res);
844 res = optimize (res);
848 /* return the pointer to the Phi node. This node might be deallocated! */
853 get_r_value_internal (ir_node *block, int pos, ir_mode *mode);
855 /** This function computes the predecessors for a real Phi node, and then
856 allocates and returns this node. The routine called to allocate the
857 node might optimize it away and return a real value, or even a pointer
858 to a deallocated Phi node on top of the obstack!
859 This function is called with an in-array of proper size. **/
860 static inline ir_node *
861 phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
863 ir_node *prevBlock, *res;
866 /* This loop goes to all predecessor blocks of the block the Phi node is in
867 and there finds the operands of the Phi node by calling
868 get_r_value_internal. */
869 for (i = 1; i <= ins; ++i) {
870 assert (block->in[i]);
871 prevBlock = block->in[i]->in[0]; /* go past control flow op to prev block */
873 nin[i-1] = get_r_value_internal (prevBlock, pos, mode);
876 /* After collecting all predecessors into the array nin a new Phi node
877 with these predecessors is created. This constructor contains an
878 optimization: If all predecessors of the Phi node are identical it
879 returns the only operand instead of a new Phi node. If the value
880 passes two different control flow edges without being defined, and
881 this is the second path treated, a pointer to the node that will be
882 allocated for the first path (recursion) is returned. We already
883 know the address of this node, as it is the next node to be allocated
884 and will be placed on top of the obstack. (The obstack is a _stack_!) */
885 res = new_r_Phi_in (current_ir_graph, block, mode, nin, ins);
887 /* Now we now the value for "pos" and can enter it in the array with
888 all known local variables. Attention: this might be a pointer to
889 a node, that later will be allocated!!! See new_r_Phi_in.
890 If this is called in mature, after some set_value in the same block,
891 the proper value must not be overwritten:
893 get_value (makes Phi0, put's it into graph_arr)
894 set_value (overwrites Phi0 in graph_arr)
895 mature_block (upgrades Phi0, puts it again into graph_arr, overwriting
898 if (!block->attr.block.graph_arr[pos]) {
899 block->attr.block.graph_arr[pos] = res;
901 /* printf(" value already computed by %s\n",
902 id_to_str(block->attr.block.graph_arr[pos]->op->name)); */
908 /* This function returns the last definition of a variable. In case
909 this variable was last defined in a previous block, Phi nodes are
910 inserted. If the part of the firm graph containing the definition
911 is not yet constructed, a dummy Phi node is returned. */
913 get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
916 /* There are 4 cases to treat.
918 1. The block is not mature and we visit it the first time. We can not
919 create a proper Phi node, therefore a Phi0, i.e., a Phi without
920 predecessors is returned. This node is added to the linked list (field
921 "link") of the containing block to be completed when this block is
922 matured. (Comlpletion will add a new Phi and turn the Phi0 into an Id
925 2. The value is already known in this block, graph_arr[pos] is set and we
926 visit the block the first time. We can return the value without
927 creating any new nodes.
929 3. The block is mature and we visit it the first time. A Phi node needs
930 to be created (phi_merge). If the Phi is not needed, as all it's
931 operands are the same value reaching the block through different
932 paths, it's optimized away and the value itself is returned.
934 4. The block is mature, and we visit it the second time. Now two
935 subcases are possible:
936 * The value was computed completely the last time we were here. This
937 is the case if there is no loop. We can return the proper value.
938 * The recursion that visited this node and set the flag did not
939 return yet. We are computing a value in a loop and need to
940 break the recursion without knowing the result yet.
941 @@@ strange case. Straight forward we would create a Phi before
942 starting the computation of it's predecessors. In this case we will
943 find a Phi here in any case. The problem is that this implementation
944 only creates a Phi after computing the predecessors, so that it is
945 hard to compute self references of this Phi. @@@
946 There is no simple check for the second subcase. Therefore we check
947 for a second visit and treat all such cases as the second subcase.
948 Anyways, the basic situation is the same: we reached a block
949 on two paths without finding a definition of the value: No Phi
950 nodes are needed on both paths.
951 We return this information "Two paths, no Phi needed" by a very tricky
952 implementation that relies on the fact that an obstack is a stack and
953 will return a node with the same address on different allocations.
954 Look also at phi_merge and new_r_phi_in to understand this.
955 @@@ Unfortunately this does not work, see testprogram
956 three_cfpred_example.
960 /* case 4 -- already visited. */
961 if (get_irn_visited(block) == get_irg_visited(current_ir_graph)) return NULL;
963 /* visited the first time */
964 set_irn_visited(block, get_irg_visited(current_ir_graph));
966 /* Get the local valid value */
967 res = block->attr.block.graph_arr[pos];
969 /* case 2 -- If the value is actually computed, return it. */
970 if (res) { return res;};
972 if (block->attr.block.matured) { /* case 3 */
974 /* The Phi has the same amount of ins as the corresponding block. */
975 int ins = get_irn_arity(block);
977 NEW_ARR_A (ir_node *, nin, ins);
979 /* Phi merge collects the predecessors and then creates a node. */
980 res = phi_merge (block, pos, mode, nin, ins);
982 } else { /* case 1 */
983 /* The block is not mature, we don't know how many in's are needed. A Phi
984 with zero predecessors is created. Such a Phi node is called Phi0
985 node. (There is also an obsolete Phi0 opcode.) The Phi0 is then added
986 to the list of Phi0 nodes in this block to be matured by mature_block
988 The Phi0 has to remember the pos of it's internal value. If the real
989 Phi is computed, pos is used to update the array with the local
992 res = new_r_Phi0 (current_ir_graph, block, mode);
993 res->attr.phi0_pos = pos;
994 res->link = block->link;
998 /* If we get here, the frontend missed a use-before-definition error */
1001 printf("Error: no value set. Use of undefined variable. Initializing
1003 assert (mode->code >= irm_f && mode->code <= irm_p);
1004 res = new_r_Const (current_ir_graph, block, mode,
1005 tarval_mode_null[mode->code]);
1008 /* The local valid value is available now. */
1009 block->attr.block.graph_arr[pos] = res;
1016 /** This is the simple algorithm. If first generates a Phi0, then
1017 it starts the recursion. This causes an Id at the entry of
1018 every block that has no definition of the value! **/
1020 #if USE_EXPICIT_PHI_IN_STACK
1022 Phi_in_stack * new_Phi_in_stack() { return NULL; }
1023 void free_Phi_in_stack(Phi_in_stack *s) { }
1027 new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
1028 ir_node **in, int ins)
1031 ir_node *res, *known;
1033 /* Allocate a new node on the obstack. The allocation copies the in
1035 res = new_ir_node (irg, block, op_Phi, mode, ins, in);
1037 /* This loop checks whether the Phi has more than one predecessor.
1038 If so, it is a real Phi node and we break the loop. Else the
1039 Phi node merges the same definition on several paths and therefore
1040 is not needed. Don't consider Bad nodes! */
1042 for (i=0; i < ins; ++i)
1044 if (in[i]==res || in[i]==known || is_Bad(in[i])) continue;
1052 /* i==ins: there is at most one predecessor, we don't need a phi node. */
1055 obstack_free (current_ir_graph->obst, res);
1058 /* A undefined value, e.g., in unreachable code. */
1062 res = optimize (res);
1070 get_r_value_internal (ir_node *block, int pos, ir_mode *mode);
1072 /** This function allocates a dummy Phi node to break recursions,
1073 computes the predecessors for the real phi node, and then
1074 allocates and returns this node. The routine called to allocate the
1075 node might optimize it away and return a real value.
1076 This function is called with an in-array of proper size. **/
1077 static inline ir_node *
1078 phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
1080 ir_node *prevBlock, *res, *phi0;
1084 /* If this block has no value at pos create a Phi0 and remember it
1085 in graph_arr to break recursions. */
1087 if (!block->attr.block.graph_arr[pos]) {
1088 /* This is commented out as collapsing to Bads is no good idea.
1089 Either we need an assert here, or we need to call a routine
1090 that deals with this case as appropriate for the given language.
1091 Right now a self referencing Id is created which will crash irg_vryfy().
1093 Even if all variables are defined before use, it can happen that
1094 we get to the start block, if a cond has been replaced by a tuple
1095 (bad, jmp). As the start has a self referencing control flow edge,
1096 we get a self referencing Id, which is hard to optimize away. We avoid
1097 this by defining the value as a Bad node.
1098 Returning a const with tarval_bad is a preliminary solution. In some
1099 situations we might want a Warning or an Error. */
1101 if (block == get_irg_start_block(current_ir_graph)) {
1102 block->attr.block.graph_arr[pos] = new_Const(mode, tarval_bad);
1103 return block->attr.block.graph_arr[pos];
1105 phi0 = new_r_Phi0(current_ir_graph, block, mode);
1106 block->attr.block.graph_arr[pos] = phi0;
1110 /* This loop goes to all predecessor blocks of the block the Phi node
1111 is in and there finds the operands of the Phi node by calling
1112 get_r_value_internal. */
1113 for (i = 1; i <= ins; ++i) {
1114 assert (block->in[i]);
1115 if (is_Bad(block->in[i])) {
1116 /* In case a Cond has been optimized we would get right to the start block
1117 with an invalid definition. */
1118 nin[i-1] = new_Bad();
1121 prevBlock = block->in[i]->in[0]; /* go past control flow op to prev block */
1123 if (!is_Bad(prevBlock)) {
1124 nin[i-1] = get_r_value_internal (prevBlock, pos, mode);
1126 nin[i-1] = new_Bad();
1130 /* After collecting all predecessors into the array nin a new Phi node
1131 with these predecessors is created. This constructor contains an
1132 optimization: If all predecessors of the Phi node are identical it
1133 returns the only operand instead of a new Phi node. */
1134 res = new_r_Phi_in (current_ir_graph, block, mode, nin, ins);
1136 /* In case we allocated a Phi0 node at the beginning of this procedure,
1137 we need to exchange this Phi0 with the real Phi. */
1139 exchange(phi0, res);
1140 block->attr.block.graph_arr[pos] = res;
1146 /* This function returns the last definition of a variable. In case
1147 this variable was last defined in a previous block, Phi nodes are
1148 inserted. If the part of the firm graph containing the definition
1149 is not yet constructed, a dummy Phi node is returned. */
1151 get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
1154 /* There are 4 cases to treat.
1156 1. The block is not mature and we visit it the first time. We can not
1157 create a proper Phi node, therefore a Phi0, i.e., a Phi without
1158 predecessors is returned. This node is added to the linked list (field
1159 "link") of the containing block to be completed when this block is
1160 matured. (Comlpletion will add a new Phi and turn the Phi0 into an Id
1163 2. The value is already known in this block, graph_arr[pos] is set and we
1164 visit the block the first time. We can return the value without
1165 creating any new nodes.
1167 3. The block is mature and we visit it the first time. A Phi node needs
1168 to be created (phi_merge). If the Phi is not needed, as all it's
1169 operands are the same value reaching the block through different
1170 paths, it's optimized away and the value itself is returned.
1172 4. The block is mature, and we visit it the second time. Now two
1173 subcases are possible:
1174 * The value was computed completely the last time we were here. This
1175 is the case if there is no loop. We can return the proper value.
1176 * The recursion that visited this node and set the flag did not
1177 return yet. We are computing a value in a loop and need to
1178 break the recursion. This case only happens if we visited
1179 the same block with phi_merge before, which inserted a Phi0.
1180 So we return the Phi0.
1183 /* case 4 -- already visited. */
1184 if (get_irn_visited(block) == get_irg_visited(current_ir_graph)) {
1185 /* As phi_merge allocates a Phi0 this value is always defined. Here
1186 is the critical difference of the two algorithms. */
1187 assert(block->attr.block.graph_arr[pos]);
1188 return block->attr.block.graph_arr[pos];
1191 /* visited the first time */
1192 set_irn_visited(block, get_irg_visited(current_ir_graph));
1194 /* Get the local valid value */
1195 res = block->attr.block.graph_arr[pos];
1197 /* case 2 -- If the value is actually computed, return it. */
1198 if (res) { return res; };
1200 if (block->attr.block.matured) { /* case 3 */
1202 /* The Phi has the same amount of ins as the corresponding block. */
1203 int ins = get_irn_arity(block);
1205 NEW_ARR_A (ir_node *, nin, ins);
1207 /* Phi merge collects the predecessors and then creates a node. */
1208 res = phi_merge (block, pos, mode, nin, ins);
1210 } else { /* case 1 */
1211 /* The block is not mature, we don't know how many in's are needed. A Phi
1212 with zero predecessors is created. Such a Phi node is called Phi0
1213 node. The Phi0 is then added to the list of Phi0 nodes in this block
1214 to be matured by mature_block later.
1215 The Phi0 has to remember the pos of it's internal value. If the real
1216 Phi is computed, pos is used to update the array with the local
1218 res = new_r_Phi0 (current_ir_graph, block, mode);
1219 res->attr.phi0_pos = pos;
1220 res->link = block->link;
1224 /* If we get here, the frontend missed a use-before-definition error */
1227 printf("Error: no value set. Use of undefined variable. Initializing
1229 assert (mode->code >= irm_f && mode->code <= irm_p);
1230 res = new_r_Const (current_ir_graph, block, mode,
1231 tarval_mode_null[mode->code]);
1234 /* The local valid value is available now. */
1235 block->attr.block.graph_arr[pos] = res;
1240 #endif /* USE_FAST_PHI_CONSTRUCTION */
1242 /* ************************************************************************** */
1244 /** Finalize a Block node, when all control flows are known. */
1245 /** Acceptable parameters are only Block nodes. */
1247 mature_block (ir_node *block)
1254 assert (get_irn_opcode(block) == iro_Block);
1256 if (!get_Block_matured(block)) {
1258 /* turn the dynamic in-array into a static one. */
1259 ins = ARR_LEN (block->in)-1;
1260 NEW_ARR_A (ir_node *, nin, ins);
1261 /* @@@ something is strange here... why isn't the array copied? */
1263 /* Traverse a chain of Phi nodes attached to this block and mature
1265 for (n = block->link; n; n=next) {
1266 inc_irg_visited(current_ir_graph);
1268 exchange (n, phi_merge (block, n->attr.phi0_pos, n->mode, nin, ins));
1271 block->attr.block.matured = 1;
1273 /* Now, as the block is a finished firm node, we can optimize it.
1274 Since other nodes have been allocated since the block was created
1275 we can not free the node on the obstack. Therefore we have to call
1277 Unfortunately the optimization does not change a lot, as all allocated
1278 nodes refer to the unoptimized node. */
1279 block = optimize_in_place(block);
1285 new_Phi (int arity, ir_node **in, ir_mode *mode)
1287 return new_r_Phi (current_ir_graph, current_ir_graph->current_block,
1292 new_Const (ir_mode *mode, tarval *con)
1294 return new_r_Const (current_ir_graph, current_ir_graph->start_block,
1299 new_Id (ir_node *val, ir_mode *mode)
1301 return new_r_Id (current_ir_graph, current_ir_graph->current_block,
1306 new_Proj (ir_node *arg, ir_mode *mode, long proj)
1308 return new_r_Proj (current_ir_graph, current_ir_graph->current_block,
1313 new_defaultProj (ir_node *arg, long max_proj)
1316 assert((arg->op==op_Cond) && (get_irn_mode(arg->in[1]) == mode_I));
1317 arg->attr.c.kind = fragmentary;
1318 arg->attr.c.default_proj = max_proj;
1319 res = new_Proj (arg, mode_X, max_proj);
1324 new_Conv (ir_node *op, ir_mode *mode)
1326 return new_r_Conv (current_ir_graph, current_ir_graph->current_block,
1331 new_Tuple (int arity, ir_node **in)
1333 return new_r_Tuple (current_ir_graph, current_ir_graph->current_block,
1338 new_Add (ir_node *op1, ir_node *op2, ir_mode *mode)
1340 return new_r_Add (current_ir_graph, current_ir_graph->current_block,
1345 new_Sub (ir_node *op1, ir_node *op2, ir_mode *mode)
1347 return new_r_Sub (current_ir_graph, current_ir_graph->current_block,
1353 new_Minus (ir_node *op, ir_mode *mode)
1355 return new_r_Minus (current_ir_graph, current_ir_graph->current_block,
1360 new_Mul (ir_node *op1, ir_node *op2, ir_mode *mode)
1362 return new_r_Mul (current_ir_graph, current_ir_graph->current_block,
1367 new_Quot (ir_node *memop, ir_node *op1, ir_node *op2)
1369 return new_r_Quot (current_ir_graph, current_ir_graph->current_block,
1374 new_DivMod (ir_node *memop, ir_node *op1, ir_node *op2)
1376 return new_r_DivMod (current_ir_graph, current_ir_graph->current_block,
1381 new_Div (ir_node *memop, ir_node *op1, ir_node *op2)
1383 return new_r_Div (current_ir_graph, current_ir_graph->current_block,
1388 new_Mod (ir_node *memop, ir_node *op1, ir_node *op2)
1390 return new_r_Mod (current_ir_graph, current_ir_graph->current_block,
1395 new_And (ir_node *op1, ir_node *op2, ir_mode *mode)
1397 return new_r_And (current_ir_graph, current_ir_graph->current_block,
1402 new_Or (ir_node *op1, ir_node *op2, ir_mode *mode)
1404 return new_r_Or (current_ir_graph, current_ir_graph->current_block,
1409 new_Eor (ir_node *op1, ir_node *op2, ir_mode *mode)
1411 return new_r_Eor (current_ir_graph, current_ir_graph->current_block,
1416 new_Not (ir_node *op, ir_mode *mode)
1418 return new_r_Not (current_ir_graph, current_ir_graph->current_block,
1423 new_Shl (ir_node *op, ir_node *k, ir_mode *mode)
1425 return new_r_Shl (current_ir_graph, current_ir_graph->current_block,
1430 new_Shr (ir_node *op, ir_node *k, ir_mode *mode)
1432 return new_r_Shr (current_ir_graph, current_ir_graph->current_block,
1437 new_Shrs (ir_node *op, ir_node *k, ir_mode *mode)
1439 return new_r_Shrs (current_ir_graph, current_ir_graph->current_block,
1444 new_Rotate (ir_node *op, ir_node *k, ir_mode *mode)
1446 return new_r_Rot (current_ir_graph, current_ir_graph->current_block,
1451 new_Abs (ir_node *op, ir_mode *mode)
1453 return new_r_Abs (current_ir_graph, current_ir_graph->current_block,
1458 new_Cmp (ir_node *op1, ir_node *op2)
1460 return new_r_Cmp (current_ir_graph, current_ir_graph->current_block,
1467 return new_r_Jmp (current_ir_graph, current_ir_graph->current_block);
1471 new_Cond (ir_node *c)
1473 return new_r_Cond (current_ir_graph, current_ir_graph->current_block, c);
1477 new_Call (ir_node *store, ir_node *callee, int arity, ir_node **in,
1480 return new_r_Call (current_ir_graph, current_ir_graph->current_block,
1481 store, callee, arity, in, type);
1485 new_Return (ir_node* store, int arity, ir_node **in)
1487 return new_r_Return (current_ir_graph, current_ir_graph->current_block,
1492 new_Raise (ir_node *store, ir_node *obj)
1494 return new_r_Raise (current_ir_graph, current_ir_graph->current_block,
1499 new_Load (ir_node *store, ir_node *addr)
1501 return new_r_Load (current_ir_graph, current_ir_graph->current_block,
1506 new_Store (ir_node *store, ir_node *addr, ir_node *val)
1508 return new_r_Store (current_ir_graph, current_ir_graph->current_block,
1513 new_Alloc (ir_node *store, ir_node *size, type *alloc_type,
1516 return new_r_Alloc (current_ir_graph, current_ir_graph->current_block,
1517 store, size, alloc_type, where);
1521 new_Free (ir_node *store, ir_node *ptr, ir_node *size, type *free_type)
1523 return new_r_Free (current_ir_graph, current_ir_graph->current_block,
1524 store, ptr, size, free_type);
1528 new_simpleSel (ir_node *store, ir_node *objptr, entity *ent)
1529 /* GL: objptr was called frame before. Frame was a bad choice for the name
1530 as the operand could as well be a pointer to a dynamic object. */
1532 return new_r_Sel (current_ir_graph, current_ir_graph->current_block,
1533 store, objptr, 0, NULL, ent);
1537 new_Sel (ir_node *store, ir_node *objptr, int n_index, ir_node **index, entity *sel)
1539 return new_r_Sel (current_ir_graph, current_ir_graph->current_block,
1540 store, objptr, n_index, index, sel);
1544 new_SymConst (type_or_id_p value, symconst_kind kind)
1546 return new_r_SymConst (current_ir_graph, current_ir_graph->current_block,
1551 new_Sync (int arity, ir_node** in)
1553 return new_r_Sync (current_ir_graph, current_ir_graph->current_block,
1561 return current_ir_graph->bad;
1564 /* ********************************************************************* */
1565 /* Comfortable interface with automatic Phi node construction. */
1566 /* (Uses also constructors of ?? interface, except new_Block. */
1567 /* ********************************************************************* */
1569 /** Block construction **/
1570 /* immature Block without predecessors */
1571 ir_node *new_immBlock (void) {
1574 /* creates a new dynamic in-array as length of in is -1 */
1575 res = new_ir_node (current_ir_graph, NULL, op_Block, mode_R, -1, NULL);
1576 current_ir_graph->current_block = res;
1577 res->attr.block.matured = 0;
1578 set_Block_block_visited(res, 0);
1580 /* Create and initialize array for Phi-node construction. */
1581 res->attr.block.graph_arr = NEW_ARR_D (ir_node *, current_ir_graph->obst,
1582 current_ir_graph->n_loc);
1583 memset(res->attr.block.graph_arr, 0, sizeof(ir_node *)*current_ir_graph->n_loc);
1585 /* Immature block may not be optimized! */
1591 /* add an adge to a jmp/control flow node */
1593 add_in_edge (ir_node *block, ir_node *jmp)
1595 if (block->attr.block.matured) {
1596 printf("Error: Block already matured!\n");
1599 assert (jmp != NULL);
1600 ARR_APP1 (ir_node *, block->in, jmp);
1604 /* changing the current block */
1606 switch_block (ir_node *target)
1608 current_ir_graph->current_block = target;
1611 /* ************************ */
1612 /* parameter administration */
1614 /* get a value from the parameter array from the current block by its index */
1616 get_value (int pos, ir_mode *mode)
1618 inc_irg_visited(current_ir_graph);
1619 return get_r_value_internal (current_ir_graph->current_block, pos + 1, mode);
1623 /* set a value at position pos in the parameter array from the current block */
1625 set_value (int pos, ir_node *value)
1627 current_ir_graph->current_block->attr.block.graph_arr[pos + 1] = value;
1630 /* get the current store */
1634 /* GL: one could call get_value instead */
1635 inc_irg_visited(current_ir_graph);
1636 return get_r_value_internal (current_ir_graph->current_block, 0, mode_M);
1639 /* set the current store */
1641 set_store (ir_node *store)
1643 /* GL: one could call set_value instead */
1644 current_ir_graph->current_block->attr.block.graph_arr[0] = store;
1647 /* ********************************************************************* */
1650 /* call once for each run of the library */