X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Firscc.c;h=a37b057f4aa21e2ef689007271d2723133dad7da;hb=abe1a1208ecb24b75b001bfe98ea0c500407a094;hp=8b541f93177a778ca497cd6c2ad32b658a68897e;hpb=1a26f4853c07d1ecd68a097409dd602edfe29eff;p=libfirm diff --git a/ir/ana/irscc.c b/ir/ana/irscc.c index 8b541f931..a37b057f4 100644 --- a/ir/ana/irscc.c +++ b/ir/ana/irscc.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 1995-2008 University of Karlsruhe. All right reserved. + * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved. * * This file is part of libFirm. * @@ -25,7 +25,6 @@ * Chapter 5.2.1.2. * @author Goetz Lindenmaier * @date 7.2002 - * @version $Id$ */ #include "config.h" @@ -41,6 +40,7 @@ #include "irdump.h" #include "array.h" #include "pmap.h" +#include "ircons.h" /* A variant of the loop tree that avoids loops without head. This reduces the depth of the loop tree. */ @@ -58,7 +58,7 @@ static int loop_node_cnt = 0; /** Counter to generate depth first numbering of visited nodes. */ static int current_dfn = 1; -static int max_loop_depth = 0; +static unsigned max_loop_depth = 0; void link_to_reg_end(ir_node *n, void *env); void set_projx_link(ir_node *cb_projx, ir_node *end_projx); @@ -97,7 +97,7 @@ static inline scc_info *new_scc_info(struct obstack *obst) */ static inline void mark_irn_in_stack(ir_node *n) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); scc->in_stack = 1; } @@ -107,7 +107,7 @@ static inline void mark_irn_in_stack(ir_node *n) */ static inline void mark_irn_not_in_stack(ir_node *n) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); scc->in_stack = 0; } @@ -117,7 +117,7 @@ static inline void mark_irn_not_in_stack(ir_node *n) */ static inline int irn_is_in_stack(ir_node *n) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); return scc->in_stack; } @@ -127,7 +127,7 @@ static inline int irn_is_in_stack(ir_node *n) */ static inline void set_irn_uplink(ir_node *n, int uplink) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); scc->uplink = uplink; } @@ -137,7 +137,7 @@ static inline void set_irn_uplink(ir_node *n, int uplink) */ static int get_irn_uplink(ir_node *n) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); return scc->uplink; } @@ -147,7 +147,7 @@ static int get_irn_uplink(ir_node *n) */ static inline void set_irn_dfn(ir_node *n, int dfn) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); scc->dfn = dfn; } @@ -157,7 +157,7 @@ static inline void set_irn_dfn(ir_node *n, int dfn) */ static int get_irn_dfn(ir_node *n) { - scc_info *scc = get_irn_link(n); + scc_info *scc = (scc_info*) get_irn_link(n); assert(scc); return scc->dfn; } @@ -197,7 +197,7 @@ ir_loop * get_irn_loop(ir_node *n) /**********************************************************************/ static ir_node **stack = NULL; -static int tos = 0; /* top of stack */ +static size_t tos = 0; /* top of stack */ /** * initializes the stack @@ -229,10 +229,10 @@ static void finish_stack(void) static inline void push(ir_node *n) { if (tos == ARR_LEN(stack)) { - int nlen = ARR_LEN(stack) * 2; + size_t nlen = ARR_LEN(stack) * 2; ARR_RESIZE(ir_node *, stack, nlen); } - stack [tos++] = n; + stack[tos++] = n; mark_irn_in_stack(n); } @@ -243,7 +243,10 @@ static inline void push(ir_node *n) */ static inline ir_node *pop(void) { - ir_node *n = stack[--tos]; + ir_node *n; + + assert(tos > 0); + n = stack[--tos]; mark_irn_not_in_stack(n); return n; } @@ -255,7 +258,6 @@ static inline ir_node *pop(void) static inline void pop_scc_to_loop(ir_node *n) { ir_node *m; - int i = 0; do { m = pop(); @@ -264,13 +266,7 @@ static inline void pop_scc_to_loop(ir_node *n) set_irn_dfn(m, loop_node_cnt); add_loop_node(current_loop, m); set_irn_loop(m, current_loop); - ++i; } while (m != n); - - /* i might be bigger than 1 for dead (and that's why bad) loops */ - /* if (i > 1) - printf("Mehr als eine Iteration!!!!!!!!!!!!!!!!!!!!!!!!!!!!11111\n"); - */ } /* GL ??? my last son is my grandson??? Removes loops with no @@ -278,7 +274,7 @@ static inline void pop_scc_to_loop(ir_node *n) can't they have two loops as sons? Does it never get that far? ) */ static void close_loop(ir_loop *l) { - int last = get_loop_n_elements(l) - 1; + size_t last = get_loop_n_elements(l) - 1; loop_element lelement = get_loop_element(l, last); ir_loop *last_son = lelement.son; @@ -337,7 +333,7 @@ static ir_loop *new_loop(void) static inline void init_node(ir_node *n, void *env) { - struct obstack *obst = env; + struct obstack *obst = (struct obstack*) env; set_irn_link(n, new_scc_info(obst)); clear_backedges(n); } @@ -363,18 +359,6 @@ static inline void finish_scc(void) finish_stack(); } -#ifdef INTERPROCEDURAL_VIEW -static inline void init_ip_scc(struct obstack *obst) -{ - init_scc_common(); - cg_walk(init_node, NULL, obst); - -#if EXPERIMENTAL_LOOP_TREE - cg_walk(link_to_reg_end, NULL, NULL); -#endif -} -#endif - /** * Check weather a given node represents the outer most Start * block. In intra-procedural view this is the start block of the @@ -405,16 +389,14 @@ static inline int get_start_index(ir_node *n) #if BLOCK_BEFORE_NODE /* This version assures, that all nodes are ordered absolutely. This allows - to undef all nodes in the heap analysis if the block is false, which means - not reachable. - I.e., with this code, the order on the loop tree is correct. But a (single) - test showed the loop tree is deeper. */ - if (get_irn_op(n) == op_Phi || - is_Block(n) || - (is_Filter(n) && get_interprocedural_view()) || ( - get_irg_pinned(get_irn_irg(n)) == op_pin_state_floats && - get_irn_pinned(n) == op_pin_state_floats - )) + to undef all nodes in the heap analysis if the block is false, which + means not reachable. + I.e., with this code, the order on the loop tree is correct. But a + (single) test showed the loop tree is deeper. */ + if (get_irn_op(n) == op_Phi || + is_Block(n) || + (get_irg_pinned(get_irn_irg(n)) == op_pin_state_floats && + get_irn_pinned(n) == op_pin_state_floats)) // Here we could test for backedge at -1 which is illegal return 0; else @@ -437,7 +419,7 @@ static inline int get_start_index(ir_node *n) /** * Return non-zero if the given node is a legal loop header: - * Block, Phi, Filter. + * Block, Phi * * @param n the node to check */ @@ -445,14 +427,12 @@ static inline int is_possible_loop_head(ir_node *n) { ir_op *op = get_irn_op(n); return ((op == op_Block) || - (op == op_Phi) || - ((op == op_Filter) && get_interprocedural_view())); + (op == op_Phi)); } /** - * Returns non-zero if n is a loop header, i.e., it is a Block, Phi - * or Filter node and has predecessors within the loop and out - * of the loop. + * Returns non-zero if n is a loop header, i.e., it is a Block or Phi + * node and has predecessors within the loop and out of the loop. * * @param n the node to check * @param root only needed for assertion. @@ -491,7 +471,7 @@ static int is_head(ir_node *n, ir_node *root) /** * Returns non-zero if n is possible loop head of an endless loop. - * I.e., it is a Block, Phi or Filter node and has only predecessors + * I.e., it is a Block or Phi node and has only predecessors * within the loop. * * @param n the node to check @@ -629,7 +609,9 @@ static ir_node *find_tail(ir_node *n) res_index = largest_dfn_pred (m); break; } - if (m == n) { break; } /* It's not an unreachable loop, either. */ + /* It's not an unreachable loop, either. */ + if (m == n) + break; } //assert(0 && "no head found on stack"); } @@ -639,8 +621,10 @@ static ir_node *find_tail(ir_node *n) /* It's a completely bad loop: without Phi/Block nodes that can be a head. I.e., the code is "dying". We break the loop by setting Bad nodes. */ - int arity = get_irn_arity(n); - ir_node *bad = get_irg_bad(get_irn_irg(n)); + ir_graph *irg = get_irn_irg(n); + ir_mode *mode = get_irn_mode(n); + ir_node *bad = new_r_Bad(irg, mode); + int arity = get_irn_arity(n); for (i = -1; i < arity; ++i) { set_irn_n(n, i, bad); } @@ -652,86 +636,11 @@ static ir_node *find_tail(ir_node *n) return is_outermost_Start(n) ? NULL : get_irn_n(m, res_index); } - -#if EXPERIMENTAL_LOOP_TREE - -/* ---------------------------------------------------------------- - AS: This is experimental code to build loop trees suitable for - the heap analysis. Does not work correctly right now... :-( - - - Search in stack for the corresponding first Call-End-ProjX that - corresponds to one of the control flow predecessors of the given - block, that is the possible callers. - returns: the control predecessor to chose\ - or -1 if no corresponding Call-End-Node could be found - on the stack. - - -------------------------------------------------------------- */ - -int search_endproj_in_stack(ir_node *start_block) -{ - int i, j; - assert(is_Block(start_block)); - for (i = tos - 1; i >= 0; --i) - { - if (get_irn_op(stack[i]) == op_Proj && get_irn_mode(stack[i]) == mode_X && - get_irn_op(get_irn_n(stack[i], 0)) == op_EndReg) - { - printf("FOUND PROJ!!!!!!!!!!!!!!!!!!!!!!!!!!\n"); - ir_node *end_projx = stack[i]; - - int arity = get_irn_arity(start_block); - for (j = 0; j < arity; j++) - { - ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)), - get_Proj_proj(end_projx)); - if (get_irn_n(start_block, j) == begin_projx) - { - printf("FOUND IT!!!!!!!!!!!!!!!!!!\n"); - return(j); - } - } - } - } - return(-1); -} - - -static pmap *projx_link = NULL; - -void link_to_reg_end (ir_node *n, void *env) -{ - if (get_irn_op(n) == op_Proj && - get_irn_mode(n) == mode_X && - get_irn_op(get_irn_n(n, 0)) == op_EndReg) { - /* Reg End Projx -> Find the CallBegin Projx and hash it */ - ir_node *end_projx = n; - ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)), - get_Proj_proj(end_projx)); - set_projx_link(begin_projx, end_projx); - } -} - -void set_projx_link(ir_node *cb_projx, ir_node *end_projx) -{ - if (projx_link == NULL) - projx_link = pmap_create(); - pmap_insert(projx_link, (void *)cb_projx, (void *)end_projx); -} - -ir_node *get_projx_link(ir_node *cb_projx) -{ - return((ir_node *) pmap_get(projx_link, (void *)cb_projx)); -} - -#endif - static inline int is_outermost_loop(ir_loop *l) { return l == get_loop_outer_loop(l); } - /*-----------------------------------------------------------* * The core algorithm. * *-----------------------------------------------------------*/ @@ -840,116 +749,12 @@ static void scc(ir_node *n) } } -#ifdef INTERPROCEDURAL_VIEW -static void my_scc(ir_node *n) -{ - int i; - if (irn_visited_else_mark(n)) - return; - - /* Initialize the node */ - set_irn_dfn(n, current_dfn); /* Depth first number for this node */ - set_irn_uplink(n, current_dfn); /* ... is default uplink. */ - set_irn_loop(n, NULL); - current_dfn ++; - push(n); - - /* AS: get_start_index might return -1 for Control Flow Nodes, and thus a negative - array index would be passed to is_backedge(). But CFG Nodes dont't have a backedge array, - so is_backedge does not access array[-1] but correctly returns false! */ - - if (!is_outermost_Start(n)) { - int arity = get_irn_arity(n); - - for (i = get_start_index(n); i < arity; i++) { - ir_node *m; - if (is_backedge(n, i)) continue; - m = get_irn_n(n, i); /* get_irn_ip_pred(n, i); */ - /* if (!m || is_Unknown(m)) continue; */ - my_scc(m); - if (irn_is_in_stack(m)) { - /* Uplink of m is smaller if n->m is a backedge. - Propagate the uplink to mark the loop. */ - if (get_irn_uplink(m) < get_irn_uplink(n)) - set_irn_uplink(n, get_irn_uplink(m)); - } - } - } - - if (get_irn_dfn(n) == get_irn_uplink(n)) { - /* This condition holds for - 1) the node with the incoming backedge. - That is: We found a loop! - 2) Straight line code, because no uplink has been propagated, so the - uplink still is the same as the dfn. - - But n might not be a proper loop head for the analysis. Proper loop - heads are Block and Phi nodes. find_tail searches the stack for - Block's and Phi's and takes those nodes as loop heads for the current - loop instead and marks the incoming edge as backedge. */ - - ir_node *tail = find_tail(n); - if (tail) { - /* We have a loop, that is no straight line code, - because we found a loop head! - Next actions: Open a new loop on the loop tree and - try to find inner loops */ - -#if NO_LOOPS_WITHOUT_HEAD - /* This is an adaption of the algorithm from fiasco / optscc to - * avoid loops without Block or Phi as first node. This should - * severely reduce the number of evaluations of nodes to detect - * a fixpoint in the heap analysis. - * Further it avoids loops without firm nodes that cause errors - * in the heap analyses. */ - - ir_loop *l; - int close; - if ((get_loop_n_elements(current_loop) > 0) || (is_outermost_loop(current_loop))) { - l = new_loop(); - close = 1; - } else { - l = current_loop; - close = 0; - } -#else - ir_loop *l = new_loop(); -#endif - - /* Remove the loop from the stack ... */ - pop_scc_unmark_visit(n); - - /* The current backedge has been marked, that is temporarily eliminated, - by find tail. Start the scc algorithm - anew on the subgraph that is left (the current loop without the backedge) - in order to find more inner loops. */ - my_scc(tail); - - assert(irn_visited(n)); -#if NO_LOOPS_WITHOUT_HEAD - if (close) -#endif - close_loop(l); - } else { - /* No loop head was found, that is we have straightline code. - Pop all nodes from the stack to the current loop. */ - pop_scc_to_loop(n); - } - } -} -#endif /* INTERPROCEDURAL_VIEW */ - -/* Constructs backedge information for irg. In interprocedural view constructs - backedges for all methods called by irg, too. */ int construct_backedges(ir_graph *irg) { ir_graph *rem = current_ir_graph; ir_loop *head_rem; struct obstack temp; - assert(!get_interprocedural_view() && - "not implemented, use construct_ip_backedges()"); - max_loop_depth = 0; current_ir_graph = irg; outermost_ir_graph = irg; @@ -971,179 +776,19 @@ int construct_backedges(ir_graph *irg) assert(head_rem == current_loop); mature_loops(current_loop, irg->obst); set_irg_loop(irg, current_loop); - set_irg_loopinfo_state(irg, loopinfo_consistent); + set_irg_state(irg, IR_GRAPH_STATE_CONSISTENT_LOOPINFO); assert(get_irg_loop(irg)->kind == k_ir_loop); current_ir_graph = rem; return max_loop_depth; } - -#ifdef INTERPROCEDURAL_VIEW -int construct_ip_backedges(void) -{ - ir_graph *rem = current_ir_graph; - int rem_ipv = get_interprocedural_view(); - int i; - strcut obstack temp; - - max_loop_depth = 0; - assert(get_irp_ip_view_state() == ip_view_valid); - - outermost_ir_graph = get_irp_main_irg(); - - obstack_init(&temp); - init_ip_scc(&temp); - - current_loop = NULL; - new_loop(); /* sets current_loop */ - set_interprocedural_view(1); - - inc_max_irg_visited(); - for (i = 0; i < get_irp_n_irgs(); i++) - set_irg_visited(get_irp_irg(i), get_max_irg_visited()); - - /** We have to start the walk at the same nodes as cg_walk. **/ - /* Walk starting at unreachable procedures. Only these - * have End blocks visible in interprocedural view. */ - for (i = 0; i < get_irp_n_irgs(); i++) { - ir_node *sb; - current_ir_graph = get_irp_irg(i); - - sb = get_irg_start_block(current_ir_graph); - - if ((get_Block_n_cfgpreds(sb) > 1) || - (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) - continue; - - scc(get_irg_end(current_ir_graph)); - } - - /* Check whether we walked all procedures: there could be procedures - with cyclic calls but no call from the outside. */ - for (i = 0; i < get_irp_n_irgs(); i++) { - ir_node *sb; - current_ir_graph = get_irp_irg(i); - - /* Test start block: if inner procedure end and end block are not - * visible and therefore not marked. */ - sb = get_irg_start_block(current_ir_graph); - if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) scc(sb); - } - - /* Walk all endless loops in inner procedures. - * We recognize an inner procedure if the End node is not visited. */ - for (i = 0; i < get_irp_n_irgs(); i++) { - ir_node *e; - current_ir_graph = get_irp_irg(i); - - e = get_irg_end(current_ir_graph); - if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) { - int j; - /* Don't visit the End node. */ - for (j = 0; j < get_End_n_keepalives(e); j++) - scc(get_End_keepalive(e, j)); - } - } - - set_irg_loop(outermost_ir_graph, current_loop); - set_irg_loopinfo_state(current_ir_graph, loopinfo_ip_consistent); - assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop); - - obstack_free(&temp, NULL); - current_ir_graph = rem; - set_interprocedural_view(rem_ipv); - return max_loop_depth; -} - -void my_construct_ip_backedges(void) -{ - ir_graph *rem = current_ir_graph; - int rem_ipv = get_interprocedural_view(); - int i; - - assert(get_irp_ip_view_state() == ip_view_valid); - - outermost_ir_graph = get_irp_main_irg(); - - init_ip_scc(); - - current_loop = NULL; - new_loop(); /* sets current_loop */ - set_interprocedural_view(1); - - inc_max_irg_visited(); - for (i = 0; i < get_irp_n_irgs(); i++) - set_irg_visited(get_irp_irg(i), get_max_irg_visited()); - - /** We have to start the walk at the same nodes as cg_walk. **/ - /* Walk starting at unreachable procedures. Only these - * have End blocks visible in interprocedural view. */ - for (i = 0; i < get_irp_n_irgs(); i++) { - ir_node *sb; - current_ir_graph = get_irp_irg(i); - - sb = get_irg_start_block(current_ir_graph); - - if ((get_Block_n_cfgpreds(sb) > 1) || - (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue; - - my_scc(get_irg_end(current_ir_graph)); - } - - /* Check whether we walked all procedures: there could be procedures - with cyclic calls but no call from the outside. */ - for (i = 0; i < get_irp_n_irgs(); i++) { - ir_node *sb; - current_ir_graph = get_irp_irg(i); - - /* Test start block: if inner procedure end and end block are not - * visible and therefore not marked. */ - sb = get_irg_start_block(current_ir_graph); - if (get_irn_visited(sb) < get_irg_visited(current_ir_graph)) - scc(sb); - } - - /* Walk all endless loops in inner procedures. - * We recognize an inner procedure if the End node is not visited. */ - for (i = 0; i < get_irp_n_irgs(); i++) { - ir_node *e; - current_ir_graph = get_irp_irg(i); - - e = get_irg_end(current_ir_graph); - if (get_irn_visited(e) < get_irg_visited(current_ir_graph)) { - int j; - /* Don't visit the End node. */ - for (j = 0; j < get_End_n_keepalives(e); j++) scc(get_End_keepalive(e, j)); - } - } - - set_irg_loop(outermost_ir_graph, current_loop); - set_irg_loopinfo_state(current_ir_graph, loopinfo_ip_consistent); - assert(get_irg_loop(outermost_ir_graph)->kind == k_ir_loop); - - current_ir_graph = rem; - set_interprocedural_view(rem_ipv); -} -#endif - static void reset_backedges(ir_node *n) { if (is_possible_loop_head(n)) { -#ifdef INTERPROCEDURAL_VIEW - int rem = get_interprocedural_view(); - - set_interprocedural_view(1); clear_backedges(n); - set_interprocedural_view(1); - clear_backedges(n); - set_interprocedural_view(rem); -#else - clear_backedges(n); -#endif } } - /* static void loop_reset_backedges(ir_loop *l) { @@ -1164,9 +809,6 @@ static void loop_reset_node(ir_node *n, void *env) reset_backedges(n); } - -/** Removes all loop information. - Resets all backedges */ void free_loop_information(ir_graph *irg) { /* We can not use this recursion, as the loop might contain @@ -1176,101 +818,25 @@ void free_loop_information(ir_graph *irg) */ irg_walk_graph(irg, loop_reset_node, NULL, NULL); set_irg_loop(irg, NULL); - set_irg_loopinfo_state(current_ir_graph, loopinfo_none); + clear_irg_state(current_ir_graph, IR_GRAPH_STATE_CONSISTENT_LOOPINFO); /* We cannot free the loop nodes, they are on the obstack. */ } - void free_all_loop_information(void) { - int i; -#ifdef INTERPROCEDURAL_VIEW - int rem = get_interprocedural_view(); - set_interprocedural_view(1); /* To visit all filter nodes */ -#endif + size_t i; for (i = 0; i < get_irp_n_irgs(); i++) { free_loop_information(get_irp_irg(i)); } -#ifdef INTERPROCEDURAL_VIEW - set_interprocedural_view(rem); -#endif -} - - - - - -/* Debug stuff *************************************************/ - -static int test_loop_node(ir_loop *l) -{ - int i, has_node = 0, found_problem = 0; - loop_element le; - - assert(l && l->kind == k_ir_loop); - - if (get_loop_n_elements(l) == 0) { - found_problem = 1; - dump_loop(l, "-ha"); - } - - le = get_loop_element(l, 0); - if (*(le.kind) != k_ir_node) { - assert(le.kind && *(le.kind) == k_ir_loop); - - found_problem = 1; - dump_loop(l, "-ha"); - } - - if ((*(le.kind) == k_ir_node) && !is_possible_loop_head(le.node)) { - found_problem = 1; - dump_loop(l, "-ha"); - } - - if ((get_loop_depth(l) != 0) && - (*(le.kind) == k_ir_node) && !has_backedges(le.node)) { - found_problem = 1; - dump_loop(l, "-ha"); - } - - /* Recur */ - has_node = 0; - for (i = 0; i < get_loop_n_elements(l); ++i) { - le = get_loop_element(l, i); - if (*(le.kind) == k_ir_node) - has_node++; - else - if (test_loop_node(le.son)) found_problem = 1; - } - - if (has_node == 0) { - found_problem = 1; - dump_loop(l, "-ha"); - } - - return found_problem; -} - -/** Prints all loop nodes that - * - do not have any firm nodes, only loop sons - * - the header is not a Phi, Block or Filter. - */ -void find_strange_loop_nodes(ir_loop *l) -{ - int found_problem = 0; - found_problem = test_loop_node(l); - printf("Finished Test\n\n"); - if (found_problem) exit(0); - } /* ------------------------------------------------------------------- */ /* Simple analyses based on the loop information */ /* ------------------------------------------------------------------- */ -int is_loop_variant(ir_loop *l, ir_loop *b) +static int is_loop_variant(ir_loop *l, ir_loop *b) { - int i, n_elems; + size_t i, n_elems; if (l == b) return 1; @@ -1285,14 +851,6 @@ int is_loop_variant(ir_loop *l, ir_loop *b) return 0; } -/* Test whether a value is loop invariant. - * - * @param n The node to be tested. - * @param block A block node. We pass the block, not the loop as we must - * start off with a block loop to find all proper uses. - * - * Returns non-zero, if the node n is not changed in the loop block - * belongs to or in inner loops of this blocks loop. */ int is_loop_invariant(const ir_node *n, const ir_node *block) { ir_loop *l = get_irn_loop(block);