X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Firscc.c;h=58ecc5abbee08078b6817ca8822efc27fd277d30;hb=c5d70d65bcf0210eb0137c9ab16fb9e443be5cc5;hp=1d0909079eaf38846551c8d8e88b58af3a18f112;hpb=a2ca4ae211a8483cd255b2b6e9d534221d8e3cc2;p=libfirm diff --git a/ir/ana/irscc.c b/ir/ana/irscc.c index 1d0909079..58ecc5abb 100644 --- a/ir/ana/irscc.c +++ b/ir/ana/irscc.c @@ -20,22 +20,27 @@ #include #include "irloop_t.h" -#include "irnode.h" +#include "irnode_t.h" #include "irgraph_t.h" #include "array.h" #include "pmap.h" #include "irgwalk.h" #include "irprog_t.h" +#include "irdump.h" ir_graph *outermost_ir_graph; /* The outermost graph the scc is computed - for */ + for */ static ir_loop *current_loop; /* Current loop construction is working - on. */ + on. */ static int loop_node_cnt = 0; /* Counts the number of allocated loop nodes. - Each loop node gets a unique number. - What for? ev. remove. @@@ */ + Each loop node gets a unique number. + What for? ev. remove. @@@ */ static int current_dfn = 1; /* Counter to generate depth first numbering - of visited nodes. */ + of visited nodes. */ + +void link_to_reg_end (ir_node *n, void *env); +void set_projx_link(ir_node *cb_projx, ir_node *end_projx); +ir_node *get_projx_link(ir_node *cb_projx); /**********************************************************************/ /* Node attributes **/ @@ -52,7 +57,7 @@ typedef struct scc_info { bool in_stack; /* Marks whether node is on the stack. */ int dfn; /* Depth first search number. */ int uplink; /* dfn number of ancestor. */ - // ir_loop *loop; /* Refers to the containing loop. */ + /* ir_loop *loop; *//* Refers to the containing loop. */ /* struct section *section; xset def; @@ -69,51 +74,65 @@ static INLINE scc_info* new_scc_info(void) { static INLINE void mark_irn_in_stack (ir_node *n) { assert(get_irn_link(n)); - ((scc_info *)get_irn_link(n))->in_stack = true; + /* to slow */ + /* ((scc_info *)get_irn_link(n))->in_stack = true; */ + ((scc_info *)n->link)->in_stack = true; } static INLINE void mark_irn_not_in_stack (ir_node *n) { assert(get_irn_link(n)); - ((scc_info *)get_irn_link(n))->in_stack = false; + /* to slow */ + /* ((scc_info *)get_irn_link(n))->in_stack = false; */ + ((scc_info *)n->link)->in_stack = false; } static INLINE bool irn_is_in_stack (ir_node *n) { assert(get_irn_link(n)); - return ((scc_info *)get_irn_link(n))->in_stack; + /* to slow */ + /* return ((scc_info *)get_irn_link(n))->in_stack; */ + return ((scc_info *)n->link)->in_stack; } static INLINE void set_irn_uplink (ir_node *n, int uplink) { assert(get_irn_link(n)); - ((scc_info *)get_irn_link(n))->uplink = uplink; + /* to slow */ + /* ((scc_info *)get_irn_link(n))->uplink = uplink; */ + ((scc_info *)n->link)->uplink = uplink; } -static INLINE int +INLINE int get_irn_uplink (ir_node *n) { assert(get_irn_link(n)); - return ((scc_info *)get_irn_link(n))->uplink; + /* from fast to slow */ + /* return ((scc_info *)get_irn_link(n))->uplink; */ + return ((scc_info *)n->link)->uplink; } static INLINE void set_irn_dfn (ir_node *n, int dfn) { - if (! get_irn_link(n)) { DDMN(n); DDME(get_irg_ent(current_ir_graph));} assert(get_irn_link(n)); - ((scc_info *)get_irn_link(n))->dfn = dfn; + /* to slow */ + /* ((scc_info *)get_irn_link(n))->dfn = dfn; */ + ((scc_info *)n->link)->dfn = dfn; } -static INLINE int +INLINE int get_irn_dfn (ir_node *n) { assert(get_irn_link(n)); - return ((scc_info *)get_irn_link(n))->dfn; + /* to slow */ + /* return ((scc_info *)get_irn_link(n))->dfn; */ + return ((scc_info *)n->link)->dfn; } +#if 0 +/* Replaced node loop map by real field as hash access dominates runtime + * of the algorithm. ! */ /* Uses temporary information to set the loop */ -static INLINE void +INLINE void set_irn_loop (ir_node *n, ir_loop* loop) { - //assert(get_irn_link(n)); - //((scc_info *)get_irn_link(n))->loop = loop; assert(node_loop_map && "not initialized!"); pmap_insert(node_loop_map, (void *)n, (void *)loop); } @@ -122,15 +141,26 @@ set_irn_loop (ir_node *n, ir_loop* loop) { INLINE ir_loop * get_irn_loop (ir_node *n) { ir_loop *res = NULL; - //assert(get_irn_link(n)); - //return ((scc_info *)get_irn_link(n))->loop; - assert(node_loop_map && "not initialized!"); + if (!node_loop_map) return NULL; if (pmap_contains(node_loop_map, (void *)n)) res = (ir_loop *) pmap_get(node_loop_map, (void *)n); return res; } +#else +INLINE void +set_irn_loop (ir_node *n, ir_loop* loop) { + n->loop = loop; +} + +/* Uses temporary information to get the loop */ +INLINE ir_loop * +get_irn_loop (ir_node *n) { + return n->loop; +} +#endif + #if 0 static ir_loop *find_nodes_loop (ir_node *n, ir_loop *l) { @@ -217,6 +247,9 @@ pop_scc_to_loop (ir_node *n) do { m = pop(); + + //printf(" dfn: %d, upl %d upl-new %d ", get_irn_dfn(m), get_irn_uplink(m), loop_node_cnt+1); DDMN(m); + loop_node_cnt++; set_irn_dfn(m, loop_node_cnt); add_loop_node(current_loop, m); @@ -226,13 +259,13 @@ pop_scc_to_loop (ir_node *n) } while(m != n); if(i > 1) - printf("Mehr als eine Iteration!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n"); + printf("Mehr als eine Iteration!!!!!!!!!!!!!!!!!!!!!!!!!!!!11111\n"); } /* GL ??? my last son is my grandson??? Removes loops with no ir_nodes in them. Such loops have only another loop as son. (Why can't they have two loops as sons? Does it never get that far? ) */ -void close_loop (ir_loop *l) +static void close_loop (ir_loop *l) { int last = get_loop_n_elements(l) - 1; loop_element lelement = get_loop_element(l, last); @@ -246,13 +279,13 @@ void close_loop (ir_loop *l) lelement = get_loop_element(last_son, 0); gson = lelement.son; if(get_kind(gson) == k_ir_loop) - { + { loop_element new_last_son; - gson -> outer_loop = l; + gson -> outer_loop = l; new_last_son.son = gson; - l -> children[last] = new_last_son; - } + l -> children[last] = new_last_son; + } } current_loop = l; @@ -277,7 +310,7 @@ pop_scc_unmark_visit (ir_node *n) /* Allocates a new loop as son of current_loop. Sets current_loop to the new loop and returns the father. */ -static ir_loop *new_loop (void) { +ir_loop *new_loop (void) { ir_loop *father, *son; father = current_loop; @@ -299,6 +332,7 @@ static ir_loop *new_loop (void) { #ifdef DEBUG_libfirm son->loop_nr = get_irp_new_node_nr(); + son->link = NULL; #endif current_loop = son; @@ -358,7 +392,7 @@ ir_loop *get_loop_son (ir_loop *loop, int pos) { /* Use EXCLUSIVELY this function to add sons, otherwise the loop->n_sons is invalid! */ -static INLINE void +INLINE void add_loop_son(ir_loop *loop, ir_loop *son) { loop_element lson; lson.son = son; @@ -390,6 +424,8 @@ ir_node *get_loop_node (ir_loop *loop, int pos) { if(node_nr == pos) return(loop -> children[child_nr].node); } + DDML(loop); + printf("pos: %d\n", pos); assert(0 && "no child at pos found"); return NULL; } @@ -397,10 +433,10 @@ ir_node *get_loop_node (ir_loop *loop, int pos) { /* Use EXCLUSIVELY this function to add nodes, otherwise the loop->n_nodes is invalid! */ -static INLINE void +INLINE void add_loop_node(ir_loop *loop, ir_node *n) { loop_element ln; - ln.node=n; + ln.node = n; assert(loop && loop->kind == k_ir_loop); assert(get_kind(n) == k_ir_node); ARR_APP1 (loop_element, loop->children, ln); @@ -427,8 +463,8 @@ loop_element get_loop_element (ir_loop *loop, int pos) { } int get_loop_element_pos(ir_loop *loop, void *le) { - assert(loop && loop->kind == k_ir_loop); int i; + assert(loop && loop->kind == k_ir_loop); for (i = 0; i < get_loop_n_elements(loop); i++) if (get_loop_element(loop, i).node == le) return i; @@ -444,6 +480,24 @@ int get_loop_loop_nr(ir_loop *loop) { #endif } + +/** A field to connect additional information to a loop. Only valid + if libfirm_debug is set. */ +void set_loop_link (ir_loop *loop, void *link) { + assert(loop && loop->kind == k_ir_loop); +#ifdef DEBUG_libfirm + loop->link = link; +#endif +} +void *get_loop_link (const ir_loop *loop) { + assert(loop && loop->kind == k_ir_loop); +#ifdef DEBUG_libfirm + return loop->link; +#else + return NULL; +#endif +} + /* The outermost loop is remarked in the surrounding graph. */ void set_irg_loop(ir_graph *irg, ir_loop *loop) { assert(irg); @@ -484,8 +538,8 @@ init_node (ir_node *n, void *env) { The mem is not lost as its on the obstack. */ ir_node *cb = get_Proj_pred(n); if ((get_irn_op(cb) == op_CallBegin) || - (get_irn_op(cb) == op_EndReg) || - (get_irn_op(cb) == op_EndExcept)) { + (get_irn_op(cb) == op_EndReg) || + (get_irn_op(cb) == op_EndExcept)) { init_node(cb, NULL); init_node(get_nodes_Block(cb), NULL); } @@ -514,6 +568,10 @@ static INLINE void init_ip_scc (void) { init_scc_common(); cg_walk (init_node, NULL, NULL); + +#if EXPERIMENTAL_LOOP_TREE + cg_walk (link_to_reg_end, NULL, NULL); +#endif } /* Condition for breaking the recursion. */ @@ -534,85 +592,51 @@ static bool is_outermost_Start(ir_node *n) { if ((get_irn_op(n) == op_Block) && (n == get_irg_start_block(current_ir_graph))) { if ((!interprocedural_view) || - (current_ir_graph == outermost_ir_graph)) + (current_ir_graph == outermost_ir_graph)) return true; } #endif return false; } -/* Don't walk from nodes to blocks except for Control flow operations. */ +/* When to walk from nodes to blocks. Only for Control flow operations? */ static INLINE int get_start_index(ir_node *n) { - if (is_cfop(n) || is_fragile_op(n) || get_irn_op(n) == op_Start) - return -1; - else +#undef BLOCK_BEFORE_NODE +#define BLOCK_BEFORE_NODE 1 + +#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 || + get_irn_op(n) == op_Block || + (get_irn_op(n) == op_Filter && interprocedural_view) || + (get_irg_pinned(get_irn_irg(n)) == floats && + get_op_pinned(get_irn_op(n)) == floats)) + // Here we could test for backedge at -1 which is illegal return 0; -} + else + return -1; -/* Returns current_ir_graph and set it to the irg of predecessor index - of node n. */ -static INLINE ir_graph * -switch_irg (ir_node *n, int index) { - ir_graph *old_current = current_ir_graph; +#else - if (interprocedural_view) { - /* Only Filter and Block nodes can have predecessors in other graphs. */ - if (get_irn_op(n) == op_Filter) - n = get_nodes_Block(n); - if (get_irn_op(n) == op_Block) { - ir_node *cfop = skip_Proj(get_Block_cfgpred(n, index)); - if (is_ip_cfop(cfop)) { - current_ir_graph = get_irn_irg(cfop); - set_irg_visited(current_ir_graph, get_max_irg_visited()); - } - } - } + /* This version causes deeper loop trees (at least we verified this + for Polymor). + But it guarantees that Blocks are analysed before nodes contained in the + block. If so, we can set the value to undef if the block is not \ + executed. */ + if (is_cfop(n) || is_fragile_op(n) || get_irn_op(n) == op_Start) + return -1; + else + return 0; - return old_current; +#endif } -/* Walks up the stack passing n and then finding the node - where we walked into the irg n is contained in. - Here we switch the irg. */ -static ir_graph * -find_irg_on_stack (ir_node *n) { - ir_node *m; - ir_graph *old_current = current_ir_graph; - int i; - - if (interprocedural_view) { - for (i = tos; i >= 0; i--) { - if (stack[i] == n) break; - } - if (i < 0) i = tos; - - assert (i >= 0); - for (; i >= 0; i--) { - m = stack[i]; - /*printf(" Visiting %d ", i); DDMN(m);*/ - if (is_ip_cfop(m)) { - current_ir_graph = get_irn_irg(m); - break; - } - if (get_irn_op(m) == op_Filter) { - /* Find the corresponding ip_cfop */ - ir_node *pred = stack[i+1]; - int j; - for (j = 0; j < get_Filter_n_cg_preds(m); j++) - if (get_Filter_cg_pred(m, j) == pred) break; - if (j >= get_Filter_n_cg_preds(m)) - /* It is a filter we didn't pass as the predecessors are marked. */ - continue; - assert(get_Filter_cg_pred(m, j) == pred); - switch_irg(m, j); - break; - } - } - } - - return old_current; -} #if 0 static void test(ir_node *pred, ir_node *root, ir_node *this) { @@ -635,9 +659,10 @@ static void test(ir_node *pred, ir_node *root, ir_node *this) { /* Test for legal loop header: Block, Phi, ... */ INLINE static bool is_possible_loop_head(ir_node *n) { - return ((get_irn_op(n) == op_Block) || - (get_irn_op(n) == op_Phi) || - ((get_irn_op(n) == op_Filter) && interprocedural_view)); + ir_op *op = get_irn_op(n); + return ((op == op_Block) || + (op == op_Phi) || + ((op == op_Filter) && interprocedural_view)); } /* Returns true if n is a loop header, i.e., it is a Block, Phi @@ -647,7 +672,7 @@ INLINE static bool is_possible_loop_head(ir_node *n) { static bool is_head (ir_node *n, ir_node *root) { - int i; + int i, arity; int some_outof_loop = 0, some_in_loop = 0; /* Test for legal loop header: Block, Phi, ... */ @@ -655,14 +680,18 @@ is_head (ir_node *n, ir_node *root) return false; if (!is_outermost_Start(n)) { - for (i = get_start_index(n); i < get_irn_arity(n); i++) { + arity = get_irn_arity(n); + for (i = get_start_index(n); i < arity; i++) { ir_node *pred = get_irn_n(n, i); assert(pred); if (is_backedge(n, i)) continue; if (!irn_is_in_stack(pred)) { some_outof_loop = 1; } else { - assert(get_irn_uplink(pred) >= get_irn_uplink(root)); + if(get_irn_uplink(pred) < get_irn_uplink(root)) { + DDMN(n); DDMN(pred); DDMN(root); + assert(get_irn_uplink(pred) >= get_irn_uplink(root)); + } some_in_loop = 1; } } @@ -670,6 +699,40 @@ is_head (ir_node *n, ir_node *root) return some_outof_loop && some_in_loop; } +/* Returns true if n is possible loop head of an endless loop. + I.e., it is a Block, Phi or Filter node and has only predecessors + within the loop. + @arg root: only needed for assertion. */ +static bool +is_endless_head (ir_node *n, ir_node *root) +{ + int i, arity; + int some_outof_loop = 0, some_in_loop = 0; + + /* Test for legal loop header: Block, Phi, ... */ + if (!is_possible_loop_head(n)) + return false; + + if (!is_outermost_Start(n)) { + arity = get_irn_arity(n); + for (i = get_start_index(n); i < arity; i++) { + ir_node *pred = get_irn_n(n, i); + assert(pred); + if (is_backedge(n, i)) { continue; } + if (!irn_is_in_stack(pred)) { + some_outof_loop = 1; //printf(" some out of loop "); + } else { + if(get_irn_uplink(pred) < get_irn_uplink(root)) { + DDMN(pred); DDMN(root); + assert(get_irn_uplink(pred) >= get_irn_uplink(root)); + } + some_in_loop = 1; + } + } + } + return !some_outof_loop && some_in_loop; +} + /* Returns index of the predecessor with the smallest dfn number greater-equal than limit. */ static int @@ -678,7 +741,8 @@ smallest_dfn_pred (ir_node *n, int limit) int i, index = -2, min = -1; if (!is_outermost_Start(n)) { - for (i = get_start_index(n); i < get_irn_arity(n); i++) { + int arity = get_irn_arity(n); + for (i = get_start_index(n); i < arity; i++) { ir_node *pred = get_irn_n(n, i); assert(pred); if (is_backedge(n, i) || !irn_is_in_stack(pred)) continue; @@ -698,7 +762,8 @@ largest_dfn_pred (ir_node *n) int i, index = -2, max = -1; if (!is_outermost_Start(n)) { - for (i = get_start_index(n); i < get_irn_arity(n); i++) { + int arity = get_irn_arity(n); + for (i = get_start_index(n); i < arity; i++) { ir_node *pred = get_irn_n(n, i); if (is_backedge (n, i) || !irn_is_in_stack(pred)) continue; if (get_irn_dfn(pred) > max) { @@ -710,11 +775,14 @@ largest_dfn_pred (ir_node *n) return index; } -/* Searches the stack for possible loop heads. Tests these for backedges. - If it finds a head with an unmarked backedge it marks this edge and - returns the tail of the loop. - If it finds no backedge returns NULL. - ("disable_backedge" in fiasco) */ +/** Searches the stack for possible loop heads. Tests these for backedges. + If it finds a head with an unmarked backedge it marks this edge and + returns the tail of the loop. + If it finds no backedge returns NULL. + ("disable_backedge" in fiasco) +* +* @param n A node where uplink == dfn. +**/ static ir_node * find_tail (ir_node *n) { @@ -724,25 +792,54 @@ find_tail (ir_node *n) { /* if (!icfg && rm_cyclic_phis && remove_cyclic_phis (n)) return NULL; */ - m = stack[tos-1]; /* tos = top of stack */ if (is_head (m, n)) { res_index = smallest_dfn_pred(m, 0); if ((res_index == -2) && /* no smallest dfn pred found. */ - (n == m)) + (n == m)) return NULL; } else { - if (m == n) return NULL; - for (i = tos-2; ; --i) { + if (m == n) return NULL; // Is this to catch Phi - self loops? + for (i = tos-2; i >= 0; --i) { m = stack[i]; + if (is_head (m, n)) { res_index = smallest_dfn_pred (m, get_irn_dfn(m) + 1); if (res_index == -2) /* no smallest dfn pred found. */ res_index = largest_dfn_pred (m); + + if ((m == n) && (res_index == -2)) { + i = -1; + } + break; + } + + /* We should not walk past our selves on the stack: The upcoming nodes + are not in this loop. We assume a loop not reachable from Start. */ + if (m == n) { + i = -1; break; } + + } + + if (i < 0) { + /* A dead loop not reachable from Start. */ + for (i = tos-2; i >= 0; --i) { + m = stack[i]; + if (is_endless_head (m, n)) { + res_index = smallest_dfn_pred (m, get_irn_dfn(m) + 1); + if (res_index == -2) /* no smallest dfn pred found. */ + res_index = largest_dfn_pred (m); + break; + } + if (m == n) { break; } /* It's not an unreachable loop, either. */ + } + //assert(0 && "no head found on stack"); } + } + if (res_index <= -2) return NULL; assert (res_index > -2); set_backedge (m, res_index); @@ -750,12 +847,88 @@ find_tail (ir_node *n) { } -/* The core algorithm. *****************************************/ +#if EXPERIMENTAL_LOOP_TREE + +/* ---------------------------------------------------------------- + AS: This is experimantal 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) + { + DDMN(stack[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]; + + for(j = 0; j < get_irn_arity(start_block); j++) + { + ir_node *begin_projx = get_Block_cfgpred(get_irg_start_block(get_irn_irg(end_projx)), get_Proj_proj(end_projx)); + DDMN(begin_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)); + printf("Linked the following ProjxNodes:\n"); + DDMN(begin_projx); + DDMN(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 + + + +/*-----------------------------------------------------------* + * The core algorithm. * + *-----------------------------------------------------------*/ + static void scc (ir_node *n) { int i; - // GL @@@ remove experimental stuff ir_graph *rem; - if (irn_visited(n)) return; mark_irn_visited(n); @@ -764,11 +937,6 @@ static void scc (ir_node *n) { set_irn_uplink(n, current_dfn); /* ... is default uplink. */ set_irn_loop(n, NULL); current_dfn ++; - - /* What's this good for? - n->ana.scc.section = NULL; - */ - push(n); /* AS: get_start_index might return -1 for Control Flow Nodes, and thus a negative @@ -776,39 +944,93 @@ static void scc (ir_node *n) { so is_backedge does not access array[-1] but correctly returns false! */ if (!is_outermost_Start(n)) { - for (i = get_start_index(n); i < get_irn_arity(n); i++) { - ir_node *m; - if (is_backedge(n, i)) continue; + int arity = get_irn_arity(n); + +#if EXPERIMENTAL_LOOP_TREE + + /* This is meant to be used with the experimenatl code above. + If the above code is not used any more, this can be deleted, too.... */ + + if(interprocedural_view && + is_Block(n) && + get_irn_op(get_irn_n(n, 0)) == op_Proj && + get_irn_op(get_irn_n(get_irn_n(n, 0), 0)) == op_CallBegin) + { + /* We are at the start node of a function: + Walk to the callers in the correct order! */ + DDMN(n); + DDMN(get_irn_n(get_irn_n(n, 0), 0)); + for(i = 0; i < arity; i++) + { + int pred_nr; + ir_node *m; + + pred_nr = search_endproj_in_stack(n); + assert(pred_nr >= 0); + if(is_backedge(n, pred_nr)) + continue; + m = get_irn_n(n, pred_nr); + 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)); + } + } + } + else - m = get_irn_n(n, i); /*get_irn_ip_pred(n, i);*/ - if ((!m) || (get_irn_op(m) == op_Unknown)) continue; - scc (m); - // GL @@@ remove experimental stuff /*return_recur(n, i);*/ +#endif - 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)); + { + 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) || (get_irn_op(m) == op_Unknown)) continue; */ + 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 the node with the incoming backedge. - AS: That is: For the loop head. */ + /* 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 found a new inner loop! */ + /* 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 */ + + +#define NO_LOOPS_WITHOUT_HEAD 1 +#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 analyses. - * Firther it avoids loops without firm nodes that cause errors + * a fixpoint in the heap analysis. + * Further it avoids loops without firm nodes that cause errors * in the heap analyses. */ -#define NO_LOOPS_WITHOUT_HEAD 1 -#if NO_LOOPS_WITHOUT_HEAD + ir_loop *l; int close; if (get_loop_n_elements(current_loop) > 0) { @@ -818,27 +1040,37 @@ static void scc (ir_node *n) { l = current_loop; close = 0; } + #else + ir_loop *l = new_loop(); + #endif /* Remove the loop from the stack ... */ pop_scc_unmark_visit (n); - /* and recompute it in a better order; and so that it goes into - the new loop. */ - // GL @@@ remove experimental stuff rem = find_irg_on_stack(tail); + + /* GL @@@ remove experimental stuff rem = find_irg_on_stack(tail); */ + + /* The current backedge has been marked, that is temporarily eliminated, + by find tail. Start the scc algorithm + anew on the subgraph thats left (the current loop without the backedge) + in order to find more inner loops. */ scc (tail); - // GL @@@ remove experimental stuff current_ir_graph = rem; + + /* GL @@@ remove experimental stuff current_ir_graph = rem; */ assert (irn_visited(n)); #if NO_LOOPS_WITHOUT_HEAD if (close) #endif - close_loop(l); - } else { - /* AS: No inner loop was found. Pop all nodes from the stack - to the current loop. */ + close_loop(l); + } + else + { + /* AS: 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); } } @@ -851,7 +1083,7 @@ void construct_backedges(ir_graph *irg) { ir_loop *head_rem; assert(!interprocedural_view && - "not implemented, use construct_ip_backedges"); + "not implemented, use construct_ip_backedges"); current_ir_graph = irg; outermost_ir_graph = irg; @@ -875,6 +1107,7 @@ void construct_backedges(ir_graph *irg) { assert(head_rem == current_loop); set_irg_loop(current_ir_graph, current_loop); + set_irg_loopinfo_state(current_ir_graph, loopinfo_consistent); assert(get_irg_loop(current_ir_graph)->kind == k_ir_loop); /* irg->loops = current_loop; @@ -913,7 +1146,7 @@ void construct_ip_backedges (void) { /* Find real entry points */ 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; + (get_nodes_Block(get_Block_cfgpred(sb, 0)) != sb)) continue; /* Compute scc for this graph */ outermost_ir_graph = current_ir_graph; set_irg_visited(outermost_ir_graph, get_max_irg_visited()); @@ -923,6 +1156,7 @@ void construct_ip_backedges (void) { } 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; @@ -934,6 +1168,8 @@ void construct_ip_backedges (void) { int rem_ipv = interprocedural_view; int i; + assert(get_irp_ip_view_state() == ip_view_valid); + outermost_ir_graph = get_irp_main_irg(); init_ip_scc(); @@ -956,7 +1192,7 @@ void construct_ip_backedges (void) { 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; + (get_nodes_block(get_Block_cfgpred(sb, 0)) != sb)) continue; scc(get_irg_end(current_ir_graph)); } @@ -988,6 +1224,7 @@ void construct_ip_backedges (void) { } 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; @@ -995,17 +1232,48 @@ void construct_ip_backedges (void) { } #endif -static void reset_backedges(ir_node *n, void *env) { - if (is_possible_loop_head(n)) +static void reset_backedges(ir_node *n) { + if (is_possible_loop_head(n)) { + int rem = interprocedural_view; + interprocedural_view = 1; + clear_backedges(n); + interprocedural_view = 0; clear_backedges(n); + interprocedural_view = rem; + } +} + + +/* +static void loop_reset_backedges(ir_loop *l) { + int i; + reset_backedges(get_loop_node(l, 0)); + for (i = 0; i < get_loop_n_nodes(l); ++i) + set_irn_loop(get_loop_node(l, i), NULL); + for (i = 0; i < get_loop_n_sons(l); ++i) { + loop_reset_backedges(get_loop_son(l, i)); + } +} +*/ + +static void loop_reset_node(ir_node *n, void *env) { + set_irn_loop(n, NULL); + 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 + illegal nodes by now. Why else would we throw away the + representation? + if (get_irg_loop(irg)) loop_reset_backedges(get_irg_loop(irg)); + */ + irg_walk_graph(irg, loop_reset_node, NULL, NULL); set_irg_loop(irg, NULL); + set_irg_loopinfo_state(current_ir_graph, loopinfo_none); /* We cannot free the loop nodes, they are on the obstack. */ - irg_walk_graph(irg, NULL, reset_backedges, NULL); } @@ -1030,6 +1298,7 @@ void free_all_loop_information (void) { 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) { @@ -1055,21 +1324,33 @@ static int test_loop_node(ir_loop *l) { dump_loop(l, "-ha"); } + if ((get_loop_depth(l) != 0) && + (*(le.kind) == k_ir_node) && !has_backedges(le.node)) { + printf(" Loop head has no backedges! "); DDML(l); + printf(" "); DDMN(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 = 1; + has_node++; else if (test_loop_node(le.son)) found_problem = 1; } - if (!has_node) { + if (has_node == 0) { printf(" Loop has no firm node! "); DDML(l); found_problem = 1; dump_loop(l, "-ha"); } + if (get_loop_loop_nr(l) == 11819) + dump_loop(l, "-ha-debug"); + return found_problem; }