change lower_switch to work on tarvals instead of int
authorMatthias Braun <matze@braunis.de>
Thu, 25 Oct 2012 17:09:40 +0000 (19:09 +0200)
committerMatthias Braun <matze@braunis.de>
Thu, 25 Oct 2012 17:12:31 +0000 (19:12 +0200)
ir/lower/lower_switch.c

index 97c9b31..ef4fbb0 100644 (file)
@@ -56,8 +56,8 @@ typedef struct case_data_t {
 
 typedef struct switch_info_t {
        ir_node     *switchn;
-       long         switch_min;
-       long         switch_max;
+       ir_tarval   *switch_min;
+       ir_tarval   *switch_max;
        ir_node     *default_block;
        unsigned     num_cases;
        case_data_t *cases;
@@ -67,31 +67,26 @@ typedef struct switch_info_t {
 /**
  * analyze enough to decide if we should lower the switch
  */
-static bool analyse_switch0(switch_info_t *info, ir_node *switchn)
+static void analyse_switch0(switch_info_t *info, ir_node *switchn)
 {
-       const ir_switch_table *table         = get_Switch_table(switchn);
-       size_t                 n_entries     = ir_switch_table_get_n_entries(table);
-       long                   switch_min    = LONG_MAX;
-       long                   switch_max    = LONG_MIN;
-       unsigned               num_cases     = 0;
-       size_t                 e;
-
-       for (e = 0; e < n_entries; ++e) {
+       const ir_switch_table *table      = get_Switch_table(switchn);
+       size_t                 n_entries  = ir_switch_table_get_n_entries(table);
+       ir_mode               *mode       = get_irn_mode(get_Switch_selector(switchn));
+       ir_tarval             *switch_min = get_mode_max(mode);
+       ir_tarval             *switch_max = get_mode_min(mode);
+       unsigned               num_cases  = 0;
+
+       for (size_t e = 0; e < n_entries; ++e) {
                const ir_switch_table_entry *entry
                        = ir_switch_table_get_entry_const(table, e);
-               long minval;
-               long maxval;
                if (entry->pn == 0)
                        continue;
 
-               if (!tarval_is_long(entry->min) || !tarval_is_long(entry->max))
-                       return false;
-               minval = get_tarval_long(entry->min);
-               maxval = get_tarval_long(entry->max);
-               if (minval < switch_min)
-                       switch_min = minval;
-               if (maxval > switch_max)
-                       switch_max = maxval;
+               if (tarval_cmp(entry->min, switch_min) == ir_relation_less)
+                       switch_min = entry->min;
+               if (tarval_cmp(entry->max, switch_max) == ir_relation_greater)
+                       switch_max = entry->max;
+
                ++num_cases;
        }
 
@@ -99,7 +94,6 @@ static bool analyse_switch0(switch_info_t *info, ir_node *switchn)
        info->switch_min = switch_min;
        info->switch_max = switch_max;
        info->num_cases  = num_cases;
-       return true;
 }
 
 static int casecmp(const void *a, const void *b)
@@ -205,35 +199,38 @@ static void normalize_table(ir_node *switchn, ir_mode *new_mode,
  */
 static void normalize_switch(switch_info_t *info)
 {
-       ir_node   *switchn     = info->switchn;
-       ir_graph  *irg         = get_irn_irg(switchn);
-       ir_node   *block       = get_nodes_block(switchn);
-       ir_node   *selector    = get_Switch_selector(switchn);
-       ir_mode   *mode        = get_irn_mode(selector);
-       ir_tarval *delta       = NULL;
-       bool       change_mode = false;
-
+       ir_node   *switchn         = info->switchn;
+       ir_graph  *irg             = get_irn_irg(switchn);
+       ir_node   *block           = get_nodes_block(switchn);
+       ir_node   *selector        = get_Switch_selector(switchn);
+       ir_mode   *switch_mode     = get_irn_mode(selector);
+       ir_mode   *mode            = switch_mode;
+       ir_tarval *delta           = NULL;
+       bool       needs_normalize = false;
+
+       ir_tarval *min = info->switch_min;
        if (mode_is_signed(mode)) {
-               mode        = find_unsigned_mode(mode);
-               selector    = new_r_Conv(block, selector, mode);
-               change_mode = true;
+               mode             = find_unsigned_mode(mode);
+               selector         = new_r_Conv(block, selector, mode);
+               min              = tarval_convert_to(min, mode);
+               needs_normalize  = true;
+               info->switch_max = tarval_convert_to(info->switch_max, mode);
        }
 
        /* normalize so switch_min is at 0 */
-       if (info->switch_min != 0) {
-               dbg_info *dbgi = get_irn_dbg_info(switchn);
-               ir_node  *min_const;
-
-               delta = new_tarval_from_long(info->switch_min, mode);
+       if (min != get_mode_null(mode)) {
+               ir_node  *min_const = new_r_Const(irg, min);
+               dbg_info *dbgi      = get_irn_dbg_info(switchn);
+               selector = new_rd_Sub(dbgi, block, selector, min_const, mode);
 
-               min_const = new_r_Const(irg, delta);
-               selector  = new_rd_Sub(dbgi, block, selector, min_const, mode);
+               info->switch_max = tarval_sub(info->switch_max, min, mode);
+               info->switch_min = get_mode_null(mode);
+               delta            = min;
 
-               info->switch_max -= info->switch_min;
-               info->switch_min  = 0;
+               needs_normalize = true;
        }
 
-       if (delta != NULL || change_mode) {
+       if (needs_normalize) {
                set_Switch_selector(switchn, selector);
                normalize_table(switchn, mode, delta);
        }
@@ -337,7 +334,6 @@ static void create_out_of_bounds_check(switch_info_t *info)
        dbg_info   *dbgi          = get_irn_dbg_info(switchn);
        ir_node    *selector      = get_Switch_selector(switchn);
        ir_node    *block         = get_nodes_block(switchn);
-       ir_mode    *cmp_mode      = get_irn_mode(selector);
        ir_node   **default_preds = NEW_ARR_F(ir_node*, 0);
        ir_node    *default_block = NULL;
        ir_node    *max_const;
@@ -351,10 +347,10 @@ static void create_out_of_bounds_check(switch_info_t *info)
        ir_node    *proj;
        size_t      n_default_preds;
 
-       assert(info->switch_min == 0);
+       assert(tarval_is_null(info->switch_min));
 
        /* check for out-of-bounds */
-       max_const  = new_r_Const_long(irg, cmp_mode, info->switch_max);
+       max_const  = new_r_Const(irg, info->switch_max);
        cmp        = new_rd_Cmp(dbgi, block, selector, max_const, ir_relation_less_equal);
        oob_cond   = new_rd_Cond(dbgi, block, cmp);
        proj_true  = new_r_Proj(oob_cond, mode_X, pn_Cond_true);
@@ -410,9 +406,6 @@ static void find_switch_nodes(ir_node *block, void *ctx)
        ir_node      *projx;
        ir_node      *switchn;
        switch_info_t info;
-       unsigned long spare;
-       bool          lower_switch = false;
-       bool          could_analyze;
 
        /* because we split critical blocks only blocks with 1 predecessors may
         * contain Proj->Cond nodes */
@@ -432,22 +425,22 @@ static void find_switch_nodes(ir_node *block, void *ctx)
                return;
        ir_nodeset_insert(&env->processed, switchn);
 
-       could_analyze = analyse_switch0(&info, switchn);
-       /* the code can't handle values which are not representable in the host */
-       if (!could_analyze) {
-               ir_fprintf(stderr, "libfirm warning: Couldn't analyse %+F (this could go wrong in the backend)\n", switchn);
-               return;
-       }
+       analyse_switch0(&info, switchn);
 
        /*
         * Here we have: num_cases and [switch_min, switch_max] interval.
         * We do an if-cascade if there are too many spare numbers.
         */
-       spare = (unsigned long) info.switch_max
-               - (unsigned long) info.switch_min
-               - (unsigned long) info.num_cases + 1;
-       lower_switch |= spare >= env->spare_size;
-       lower_switch |= info.num_cases <= env->small_switch;
+       ir_mode   *mode  = get_irn_mode(get_Switch_selector(switchn));
+       ir_tarval *spare = tarval_sub(info.switch_max, info.switch_min, mode);
+       mode  = find_unsigned_mode(mode);
+       spare = tarval_convert_to(spare, mode);
+       ir_tarval *num_cases_minus_one
+               = new_tarval_from_long(info.num_cases-1, mode);
+       spare = tarval_sub(spare, num_cases_minus_one, mode);
+       ir_tarval *spare_size = new_tarval_from_long(env->spare_size, mode);
+       bool lower_switch = (info.num_cases <= env->small_switch
+        || (tarval_cmp(spare, spare_size) & ir_relation_greater_equal));
 
        if (!lower_switch) {
                /* we won't decompose the switch. But we might have to add
@@ -463,9 +456,9 @@ static void find_switch_nodes(ir_node *block, void *ctx)
        analyse_switch1(&info);
 
        /* Now create the if cascade */
-       env->changed   = true;
+       env->changed  = true;
        info.defusers = NEW_ARR_F(ir_node*, 0);
-       block          = get_nodes_block(switchn);
+       block         = get_nodes_block(switchn);
        create_if_cascade(&info, block, info.cases, info.num_cases);
 
        /* Connect new default case users */