From 02ae66a3aad03968ce98244e723affdab1fac88e Mon Sep 17 00:00:00 2001 From: Daniel Grund Date: Thu, 23 Feb 2006 15:18:32 +0000 Subject: [PATCH] Added search for free colors in neighbourhood. --- ir/be/becopyheur.c | 95 ++++++++++++++++++++++++++++++++++------------ 1 file changed, 70 insertions(+), 25 deletions(-) diff --git a/ir/be/becopyheur.c b/ir/be/becopyheur.c index bdab70430..42d40673e 100644 --- a/ir/be/becopyheur.c +++ b/ir/be/becopyheur.c @@ -27,9 +27,12 @@ #include "becopyopt.h" #include "becopystat.h" #include "bitset.h" +#include "bearch.h" static firm_dbg_module_t *dbg = NULL; +#define SEARCH_FREE_COLORS + #define SLOTS_PINNED_GLOBAL 256 #define SLOTS_CONFLICTS 8 #define SLOTS_CHANGED_NODES 32 @@ -183,6 +186,7 @@ static INLINE void qnode_pin_local(const qnode_t *qn, ir_node *irn) { found->new_color = get_irn_col(qn->ou->co, irn); } + /** * Possible return values of qnode_color_irn() */ @@ -194,70 +198,111 @@ static INLINE void qnode_pin_local(const qnode_t *qn, ir_node *irn) { * Performs virtual re-coloring of node @p n to color @p col. Virtual colors of * other nodes are changed too, as required to preserve correctness. Function is * aware of local and global pinning. Recursive. - * @param irn The node to set the color for - * @param col The color to set + * + * If irn == trigger the color @p col must be used. (the first recoloring) + * If irn != trigger an arbitrary free color may be used. If no color is free, @p col is used. + * + * @param irn The node to set the color for + * @param col The color to set * @param trigger The irn that caused the wish to change the color of the irn + * External callers must call with trigger = irn + * * @return CHANGE_SAVE iff setting the color is possible, with all transitive effects. * CHANGE_IMPOSSIBLE iff conflicts with reg-constraintsis occured. * Else the first conflicting ir_node encountered is returned. * - * ASSUMPTION: Assumes that a life range of a single value can't be split into - * several smaller intervals where other values can live in between. - * This should be true in SSA. */ static ir_node *qnode_color_irn(const qnode_t *qn, ir_node *irn, int col, const ir_node *trigger) { const be_chordal_env_t *chordal_env = qn->ou->co->chordal_env; const arch_register_class_t *cls = chordal_env->cls; const arch_env_t *arch_env = chordal_env->main_env->arch_env; int irn_col = qnode_get_new_color(qn, irn); + ir_node *sub_res, *curr; + be_ifg_t *ifg = chordal_env->ifg; + void *iter = be_ifg_neighbours_iter_alloca(ifg); + DBG((dbg, LEVEL_3, "\t %+F \tcaused col(%+F) \t%2d --> %2d\n", trigger, irn, irn_col, col)); + /* If the target color is already set do nothing */ if (irn_col == col) { DBG((dbg, LEVEL_3, "\t %+F same color\n", irn)); return CHANGE_SAVE; } + + /* If the irn is pinned, changing color is impossible */ if (pset_find_ptr(pinned_global, irn) || qnode_is_pinned_local(qn, irn)) { DBG((dbg, LEVEL_3, "\t %+F conflicting\n", irn)); return irn; } + +#ifdef SEARCH_FREE_COLORS + /* If we resolve conflicts (recursive calls) we can use any unused color. + * In case of the first call @p col must be used. + */ + if (irn != trigger) { + bitset_t *free_cols = bitset_alloca(cls->n_regs); + arch_register_req_t req; + ir_node *curr; + int free_col; + + /* Get all possible colors */ + arch_put_non_ignore_regs(arch_env, cls, free_cols); + + /* Exclude colors not assignable to the irn */ + arch_get_register_req(arch_env, &req, irn, -1); + if (arch_register_req_is(&req, limited)) { + bitset_t *limited = bitset_alloca(cls->n_regs); + req.limited(req.limited_env, limited); + bitset_and(free_cols, limited); + } + + /* Exclude the color of the irn, because it must _change_ its color */ + bitset_clear(free_cols, irn_col); + + /* Exclude all colors used by adjacent nodes */ + be_ifg_foreach_neighbour(ifg, iter, irn, curr) + bitset_clear(free_cols, qnode_get_new_color(qn, curr)); + + free_col = bitset_next_set(free_cols, 0); + + if (free_col != -1) { + qnode_set_new_color(qn, irn, free_col); + return CHANGE_SAVE; + } + } +#endif /* SEARCH_FREE_COLORS */ + + /* If target color is not allocatable changing color is impossible */ if (!arch_reg_is_allocatable(arch_env, irn, -1, arch_register_for_index(cls, col))) { DBG((dbg, LEVEL_3, "\t %+F impossible\n", irn)); return CHANGE_IMPOSSIBLE; } /* - * Process all nodes which would conflict with this change + * If we arrive here changing color may be possible, but there may be conflicts. + * Try to color all conflicting nodes 'curr' with the color of the irn itself. */ - { - be_ifg_t *ifg = chordal_env->ifg; - void *iter = be_ifg_neighbours_iter_alloca(ifg); - ir_node *sub_res, *curr; - - /* - * Try to color all conflicting nodes 'curr' - * with the color of the irn itself. - */ - be_ifg_foreach_neighbour(ifg, iter, irn, curr) { - DBG((dbg, LEVEL_3, "\t Confl %+F(%d)\n", curr, qnode_get_new_color(qn, curr))); - if (qnode_get_new_color(qn, curr) == col && curr != trigger) { - sub_res = qnode_color_irn(qn, curr, irn_col, irn); - if (sub_res != CHANGE_SAVE) { - be_ifg_neighbours_break(ifg, iter); - return sub_res; - } + be_ifg_foreach_neighbour(ifg, iter, irn, curr) { + DBG((dbg, LEVEL_3, "\t Confl %+F(%d)\n", curr, qnode_get_new_color(qn, curr))); + if (qnode_get_new_color(qn, curr) == col && curr != trigger) { + sub_res = qnode_color_irn(qn, curr, irn_col, irn); + if (sub_res != CHANGE_SAVE) { + be_ifg_neighbours_break(ifg, iter); + return sub_res; } } } /* - * If we arrive here, all sub changes have been applied. - * So it's save to change this irn + * If we arrive here, all conflicts were resolved. + * So it is save to change this irn */ qnode_set_new_color(qn, irn, col); return CHANGE_SAVE; } + /** * Tries to set the colors for all members of this queue node; * to the target color qn->color -- 2.20.1