X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Firdom.c;h=01cd4a2b2e19807522a0090a3120c8aeb3f4f82c;hb=9ee93cffc1a8ef9df2bef8ec9c98299a89d57b15;hp=397b93e16476f3856845ae7078dc416a6f6f3572;hpb=b6bf12766204f1757ba2bebe456eb5b5a795c78e;p=libfirm diff --git a/ir/ana/irdom.c b/ir/ana/irdom.c index 397b93e16..01cd4a2b2 100644 --- a/ir/ana/irdom.c +++ b/ir/ana/irdom.c @@ -33,6 +33,7 @@ #include "irnode_t.h" #include "ircons_t.h" #include "array.h" +#include "iredges.h" #define get_dom_info(bl) (&(bl)->attr.block.dom) @@ -180,6 +181,88 @@ int block_dominates(const ir_node *a, const ir_node *b) return 0; } +/* Returns the smallest common dominator block of two nodes. */ +ir_node *node_smallest_common_dominator(ir_node *a, ir_node *b) { + ir_node *bl_a = is_Block(a) ? a : get_nodes_block(a); + ir_node *bl_b = is_Block(b) ? b : get_nodes_block(b); + ir_node *dom_bl = NULL; + + /* Check if block of a dominates block of b */ + if (block_dominates(bl_a, bl_b)) + dom_bl = bl_a; + /* Check if block of b dominates block of a */ + else if (block_dominates(bl_b, bl_a)) + dom_bl = bl_b; + else { + /* walk up dominator tree and search for first block dominating a and b */ + while (! dom_bl) { + bl_a = get_Block_idom(bl_a); + + assert(! is_Bad(bl_a) && "block is dead?"); + + if (block_dominates(bl_a, bl_b)) + dom_bl = bl_a; + } + } + + return dom_bl; +} + +/* Returns the smallest common dominator block of all users of a node. */ +ir_node *node_users_smallest_common_dominator(ir_node *irn, int handle_phi) { + int n, j, i = 0, success; + ir_node **user_blocks, *dom_bl; + const ir_edge_t *edge; + + assert(! is_Block(irn) && "WRONG USAGE of node_users_smallest_common_dominator"); + assert(edges_activated(get_irn_irg(irn)) && "need edges activated"); + + n = get_irn_n_edges(irn); + + /* get array to hold all block of the node users */ + NEW_ARR_A(ir_node *, user_blocks, n); + foreach_out_edge(irn, edge) { + ir_node *src = get_edge_src_irn(edge); + + if (is_Phi(src) && handle_phi) { + /* get the corresponding cfg predecessor block if phi handling requested */ + j = get_irn_pred_pos(src, irn); + assert(j >= 0 && "kaputt"); + user_blocks[i++] = get_Block_cfgpred_block(get_nodes_block(src), j); + } + else + user_blocks[i++] = is_Block(src) ? src : get_nodes_block(src); + } + + /* in case of only one user: return the block of the user */ + if (n == 1) + return user_blocks[0]; + + i = 0; + /* search the smallest block dominating all user blocks */ + do { + dom_bl = node_smallest_common_dominator(user_blocks[i], user_blocks[i + 1]); + success = 1; + + /* check if this block dominates all remaining blocks as well */ + for (j = i + 2; j < n; j++) { + if (! block_dominates(dom_bl, user_blocks[j])) + success = 0; + } + + if (success) + break; + + /* inherit the dominator block of the first (i + 1) users */ + user_blocks[++i] = dom_bl; + } while (i < n - 1); + + assert(success && "no block found dominating all users"); + + return dom_bl; +} + + /* Get the first node in the list of nodes dominated by a given block. */ ir_node *get_Block_dominated_first(const ir_node *bl) { @@ -281,7 +364,7 @@ void postdom_tree_walk_irg(ir_graph *irg, irg_walk_func *pre, /* The root of the dominator tree should be the End block. */ ir_node *root = get_irg_end_block(irg); - assert(irg->pdom_state == dom_consistent + assert(irg->pdom_state == dom_consistent && "The dominators of the irg must be consistent"); assert(root && "The end block of the graph is NULL?"); assert(get_pdom_info(root)->idom == NULL @@ -348,13 +431,13 @@ static void assign_tree_postdom_pre_order_max(ir_node *bl, void *data) * count the number of blocks and clears the post dominance info */ static void count_and_init_blocks_pdom(ir_node *bl, void *env) { - int *n_blocks = (int *) env; - (*n_blocks) ++; + int *n_blocks = (int *) env; + (*n_blocks) ++; memset(get_pdom_info(bl), 0, sizeof(dom_info)); - set_Block_ipostdom(bl, NULL); - set_Block_postdom_pre_num(bl, -1); - set_Block_postdom_depth(bl, -1); + set_Block_ipostdom(bl, NULL); + set_Block_postdom_pre_num(bl, -1); + set_Block_postdom_depth(bl, -1); } /** temporary type used while constructing the dominator / post dominator tree. */ @@ -387,7 +470,7 @@ typedef struct { * Start block misses control dead blocks. */ static void init_tmp_dom_info(ir_node *bl, tmp_dom_info *parent, - tmp_dom_info *tdi_list, int* used) { + tmp_dom_info *tdi_list, int *used) { tmp_dom_info *tdi; int i; @@ -420,7 +503,7 @@ static void init_tmp_dom_info(ir_node *bl, tmp_dom_info *parent, * End block misses blocks in endless loops. */ static void init_tmp_pdom_info(ir_node *bl, tmp_dom_info *parent, - tmp_dom_info *tdi_list, int* used) { + tmp_dom_info *tdi_list, int* used) { tmp_dom_info *tdi; int i; @@ -448,6 +531,22 @@ static void init_tmp_pdom_info(ir_node *bl, tmp_dom_info *parent, assert(is_Block(pred)); init_tmp_pdom_info(pred, tdi, tdi_list, used); } + + /* Handle keep-alives. Note that the preprocessing + in init_construction() had already killed all + phantom keep-alive edges. All remaining block keep-alives + are really edges to endless loops. + */ + if (bl == get_irg_end_block(current_ir_graph)) { + ir_node *end = get_irg_end(current_ir_graph); + + for (i = get_irn_arity(end) - 1; i >= 0; --i) { + ir_node *pred = get_irn_n(end, i); + + if (is_Block(pred)) + init_tmp_pdom_info(pred, tdi, tdi_list, used); + } + } } static void dom_compress(tmp_dom_info *v) @@ -497,7 +596,7 @@ static void count_and_init_blocks_dom(ir_node *bl, void *env) { * * - count the number of blocks * - clear the dominance info - * - remove block-keepalives of live blocks to reduce + * - remove Block-keepalives of live blocks to reduce * the number of "phantom" block edges * * @param irg the graph @@ -516,14 +615,14 @@ static int init_construction(ir_graph *irg, irg_walk_func *pre) { /* now visit the unreachable (from End) Blocks and remove unnecessary keep-alives */ end = get_irg_end(irg); - arity = get_irn_arity(end); + arity = get_End_n_keepalives(end); if (arity) { /* we have keep-alives */ ir_node **in; int i, j; NEW_ARR_A(ir_node *, in, arity); for (i = j = 0; i < arity; i++) { - ir_node *pred = get_irn_n(end, i); + ir_node *pred = get_End_keepalive(end, i); if (get_irn_op(pred) == op_Block) { if (Block_not_block_visited(pred)) { @@ -538,7 +637,7 @@ static int init_construction(ir_graph *irg, irg_walk_func *pre) { } if (j != arity) { /* we kill some Block keep-alives */ - set_irn_in(end, j, in); + set_End_keepalives(end, j, in); set_irg_outs_inconsistent(irg); } } @@ -569,8 +668,7 @@ void compute_doms(ir_graph *irg) { tdi_list = xcalloc(n_blocks, sizeof(tdi_list[0])); /* We need the out data structure. */ - if (irg->outs_state != outs_consistent) - compute_irg_outs(irg); + assure_irg_outs(irg); /* this with a standard walker as passing the parent to the sons isn't simple. */ @@ -667,6 +765,11 @@ void compute_doms(ir_graph *irg) { } } +void assure_doms(ir_graph *irg) { + if (get_irg_dom_state(irg) != dom_consistent) + compute_doms(irg); +} + void free_dom(ir_graph *irg) { /* Update graph state */ assert(get_irg_phase_state(current_ir_graph) != phase_building); @@ -697,8 +800,7 @@ void compute_postdoms(ir_graph *irg) { tdi_list = xcalloc(n_blocks, sizeof(tdi_list[0])); /* We need the out data structure. */ - if (irg->outs_state != outs_consistent) - compute_irg_outs(irg); + assure_irg_outs(irg); /* this with a standard walker as passing the parent to the sons isn't simple. */ @@ -717,9 +819,9 @@ void compute_postdoms(ir_graph *irg) { tmp_dom_info *v; /* Step 2 */ - irn_arity = get_Block_n_cfg_outs(w->block); + irn_arity = get_Block_n_cfg_outs_ka(w->block); for (j = 0; j < irn_arity; j++) { - ir_node *succ = get_Block_cfg_out(w->block, j); + ir_node *succ = get_Block_cfg_out_ka(w->block, j); tmp_dom_info *u; if (get_Block_postdom_pre_num (succ) == -1) @@ -774,6 +876,11 @@ void compute_postdoms(ir_graph *irg) { } } +void assure_postdoms(ir_graph *irg) { + if (get_irg_postdom_state(irg) != dom_consistent) + compute_postdoms(irg); +} + void free_postdom(ir_graph *irg) { /* Update graph state */ assert(get_irg_phase_state(current_ir_graph) != phase_building);