fixed warning
[libfirm] / ir / be / belower.c
index 535d8b2..b26d4ab 100644 (file)
 #include "iredges_t.h"
 #include "irgwalk.h"
 
+#ifdef HAVE_MALLOC_H
+ #include <malloc.h>
+#endif
+#ifdef HAVE_ALLOCA_H
+ #include <alloca.h>
+#endif
+
 #undef is_Perm
 #define is_Perm(arch_env, irn) (arch_irn_classify(arch_env, irn) == arch_irn_class_perm)
 
@@ -164,17 +171,17 @@ static perm_cycle_t *get_perm_cycle(perm_cycle_t *cycle, reg_pair_t *pairs, int
        int cur_idx      = pairs[start].out_reg->index;
        int cur_pair_idx = start;
        int n_pairs_done = get_n_checked_pairs(pairs, n);
-       int idx, done = 0;
+       int idx;
        perm_type_t cycle_tp = PERM_CYCLE;
 
        /* We could be right in the middle of a chain, so we need to find the start */
-       while (head != cur_idx && !done) {
+       while (head != cur_idx) {
                /* goto previous register in cycle or chain */
                cur_pair_idx = get_pairidx_for_regidx(pairs, n, head, 1);
 
                if (cur_pair_idx < 0) {
                        cycle_tp = PERM_CHAIN;
-                       done = 1;
+                       break;
                }
                else {
                        head  = pairs[cur_pair_idx].in_reg->index;
@@ -183,16 +190,16 @@ static perm_cycle_t *get_perm_cycle(perm_cycle_t *cycle, reg_pair_t *pairs, int
        }
 
        /* assume worst case: all remaining pairs build a cycle or chain */
-       cycle->elems    = calloc((n - n_pairs_done) * 2, sizeof(cycle->elems[0]));
+       cycle->elems    = xcalloc((n - n_pairs_done) * 2, sizeof(cycle->elems[0]));
        cycle->n_elems  = 2;  /* initial number of elements is 2 */
        cycle->elems[0] = pairs[start].in_reg;
        cycle->elems[1] = pairs[start].out_reg;
        cycle->type     = cycle_tp;
-       n_pairs_done++;
+       cur_idx         = pairs[start].out_reg->index;
 
        idx = 2;
        /* check for cycle or end of a chain */
-       while (cur_idx != head && n_pairs_done < n) {
+       while (cur_idx != head) {
                /* goto next register in cycle or chain */
                cur_pair_idx = get_pairidx_for_regidx(pairs, n, cur_idx, 0);
 
@@ -205,8 +212,6 @@ static perm_cycle_t *get_perm_cycle(perm_cycle_t *cycle, reg_pair_t *pairs, int
                if (cur_idx != head) {
                        cycle->elems[idx++] = pairs[cur_pair_idx].out_reg;
                        cycle->n_elems++;
-
-                       n_pairs_done++;
                }
                else {
                        /* we are there where we started -> CYCLE */
@@ -253,7 +258,7 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
        ir_node         *arg1, *arg2, *res1, *res2;
        ir_node         *cpyxchg = NULL;
 
-       arch_env = env->chord_env->main_env->arch_env;
+       arch_env = env->chord_env->birg->main_env->arch_env;
        do_copy  = env->do_copy;
        mod      = env->dbg_module;
        block    = get_nodes_block(irn);
@@ -272,7 +277,7 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
        assert(n == get_irn_n_edges(irn) && "perm's in and out numbers different");
 
        reg_class = arch_get_irn_register(arch_env, get_irn_n(irn, 0))->reg_class;
-       pairs     = calloc(n, sizeof(pairs[0]));
+       pairs     = alloca(n * sizeof(pairs[0]));
 
        /* build the list of register pairs (in, out) */
        i = 0;
@@ -326,7 +331,7 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
 
                /* go to the first not-checked pair */
                while (pairs[i].checked) i++;
-               cycle = calloc(1, sizeof(*cycle));
+               cycle = xcalloc(1, sizeof(*cycle));
                cycle = get_perm_cycle(cycle, pairs, n, i);
 
                DB((mod, LEVEL_1, "%+F: following %s created:\n  ", irn, cycle->type == PERM_CHAIN ? "chain" : "cycle"));
@@ -346,8 +351,8 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
 //TODO: - iff PERM_CYCLE && do_copy -> determine free temp reg and insert copy to/from it before/after
 //        the copy cascade (this reduces the cycle into a chain)
 
-               /* build copy/swap nodes */
-               for (i = 0; i < cycle->n_elems - 1; i++) {
+               /* build copy/swap nodes from back to front */
+               for (i = cycle->n_elems - 2; i >= 0; i--) {
                        arg1 = get_node_for_register(pairs, n, cycle->elems[i], 0);
                        arg2 = get_node_for_register(pairs, n, cycle->elems[i + 1], 0);
 
@@ -366,6 +371,33 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
                                in[0] = arg1;
                                in[1] = arg2;
 
+                               /* At this point we have to handle the following problem:     */
+                               /*                                                            */
+                               /* If we have a cycle with more than two elements, then       */
+                               /* this could correspond to the following Perm node:          */
+                               /*                                                            */
+                               /*   +----+   +----+   +----+                                 */
+                               /*   | r1 |   | r2 |   | r3 |                                 */
+                               /*   +-+--+   +-+--+   +--+-+                                 */
+                               /*     |        |         |                                   */
+                               /*     |        |         |                                   */
+                               /*   +-+--------+---------+-+                                 */
+                               /*   |         Perm         |                                 */
+                               /*   +-+--------+---------+-+                                 */
+                               /*     |        |         |                                   */
+                               /*     |        |         |                                   */
+                               /*   +-+--+   +-+--+   +--+-+                                 */
+                               /*   |Proj|   |Proj|   |Proj|                                 */
+                               /*   | r2 |   | r3 |   | r1 |                                 */
+                               /*   +----+   +----+   +----+                                 */
+                               /*                                                            */
+                               /* This node is about to be split up into two 2x Perm's       */
+                               /* for which we need 4 Proj's and the one additional Proj     */
+                               /* of the first Perm has to be one IN of the second. So in    */
+                               /* general we need to create one additional Proj for each     */
+                               /* "middle" Perm and set this to one in node of the successor */
+                               /* Perm.                                                      */
+
                                DBG((mod, LEVEL_1, "%+F creating exchange node (%+F, %s) and (%+F, %s) with\n",
                                        irn, arg1, cycle->elems[i]->name, arg2, cycle->elems[i + 1]->name));
                                DBG((mod, LEVEL_1, "%+F                        (%+F, %s) and (%+F, %s)\n",
@@ -373,7 +405,20 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
 
                                cpyxchg = be_new_Perm(reg_class, env->chord_env->irg, block, 2, in);
 
-                               sched_remove(res1);
+                               if (i > 0) {
+                                       /* cycle is not done yet */
+                                       int pidx = get_pairidx_for_regidx(pairs, n, cycle->elems[i]->index, 0);
+
+                                       /* create intermediate proj */
+                                       res1 = new_r_Proj(get_irn_irg(irn), block, cpyxchg, get_irn_mode(res1), 0);
+
+                                       /* set as in for next Perm */
+                                       pairs[pidx].in_node = res1;
+                               }
+                               else {
+                                       sched_remove(res1);
+                               }
+
                                sched_remove(res2);
 
                                set_Proj_pred(res2, cpyxchg);
@@ -386,6 +431,14 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
 
                                arch_set_irn_register(arch_env, res2, cycle->elems[i + 1]);
                                arch_set_irn_register(arch_env, res1, cycle->elems[i]);
+
+                               /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
+                               sched_add_after(sched_point, cpyxchg);
+
+                               DBG((mod, LEVEL_1, "replacing %+F with %+F, placed new node after %+F\n", irn, cpyxchg, sched_point));
+
+                               /* set the new scheduling point */
+                               sched_point = res1;
                        }
                        else {
                                DBG((mod, LEVEL_1, "%+F creating copy node (%+F, %s) -> (%+F, %s)\n",
@@ -399,15 +452,16 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
 
                                /* exchange copy node and proj */
                                exchange(res2, cpyxchg);
-                       }
 
-                       /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
-                       sched_add_after(sched_point, cpyxchg);
+                               /* insert the copy/exchange node in schedule after the magic schedule node (see above) */
+                               sched_add_after(sched_point, cpyxchg);
 
-                       DBG((mod, LEVEL_1, "replacing %+F with %+F, placed new node after %+F\n", irn, cpyxchg, sched_point));
+                               /* set the new scheduling point */
+                               sched_point = cpyxchg;
+                       }
                }
 
-               free(cycle->elems);
+               free((void *) cycle->elems);
                free(cycle);
        }
 
@@ -417,151 +471,137 @@ static void lower_perm_node(ir_node *irn, void *walk_env) {
 
 
 
-/**
- * Adds Projs to keep nodes for each register class, which eats the
- * caller saved registers.
- * Note: The caller has to make sure, that call is a Call
- *
- * @param call     The Call node
- * @param walk_env The walker environment
- */
-static void lower_call_node(ir_node *call, const void *walk_env) {
-       const arch_env_t            *arch_env = walk_env;
-       const arch_register_class_t *reg_class;
-       int                          i, j, set_size = 0, pn, keep_arity;
-       arch_isa_t                  *isa      = arch_env_get_isa(arch_env);
-       const ir_node               *proj_T   = NULL;
-       ir_node                     **in_keep, *block = get_nodes_block(call);
-       bitset_t                    *proj_set;
-       const ir_edge_t             *edge;
-       const arch_register_t       *reg;
-
-       /* Prepare the bitset where we store the projnums which are already in use*/
-       for (i = 0; i < arch_isa_get_n_reg_class(isa); i++) {
-               reg_class  = arch_isa_get_reg_class(isa, i);
-               set_size  += arch_register_class_n_regs(reg_class);
+static int get_n_out_edges(const ir_node *irn) {
+       const ir_edge_t *edge;
+       int cnt = 0;
+
+       foreach_out_edge(irn, edge) {
+               cnt++;
        }
 
-       in_keep = malloc(set_size * sizeof(ir_node *));
+       return cnt;
+}
 
-       proj_set = bitset_malloc(set_size);
-       bitset_clear_all(proj_set);
+static ir_node *belower_skip_proj(ir_node *irn) {
+       while(is_Proj(irn))
+               irn = get_Proj_pred(irn);
+       return irn;
+}
 
-       /* check if there is a ProjT node and which arguments are used */
-       foreach_out_edge(call, edge) {
-               if (get_irn_mode(get_edge_src_irn(edge)) == mode_T)
-                       proj_T = get_edge_src_irn(edge);
-       }
+static void fix_in(ir_node *irn, ir_node *old, ir_node *nw) {
+       int i, n;
 
-       /* set all used arguments */
-       if (proj_T) {
-               foreach_out_edge(proj_T, edge) {
-                       ir_node *proj = get_edge_src_irn(edge);
+       irn = belower_skip_proj(irn);
+       n   = get_irn_arity(irn);
 
-                       assert(is_Proj(proj));
-                       bitset_set(proj_set, get_Proj_proj(proj));
+       for (i = 0; i < n; i++) {
+               if (get_irn_n(irn, i) == old) {
+                       set_irn_n(irn, i, nw);
+                       break;
                }
        }
+}
+
+static void gen_assure_different_pattern(ir_node *irn, be_irg_t *birg, ir_node *other_different) {
+       const arch_env_t          *arch_env = birg->main_env->arch_env;
+       ir_node                   *in[2], *keep, *cpy, *temp;
+       ir_node                   *block = get_nodes_block(irn);
+       firm_dbg_module_t         *mod   = firm_dbg_register("firm.be.lower");
+       const arch_register_class_t *cls = arch_get_irn_reg_class(arch_env, other_different, -1);
+
+       if (arch_irn_is(arch_env, other_different, ignore) || ! mode_is_datab(get_irn_mode(other_different))) {
+               DBG((mod, LEVEL_1, "ignore constraint for %+F because other_irn is ignore or not a datab node\n", irn));
+               return;
+       }
+
+       /* Make a not spillable copy of the different node   */
+       /* this is needed because the different irn could be */
+       /* in block far far away                             */
+       /* The copy is optimized later if not needed         */
+
+       temp = new_rd_Unknown(birg->irg, get_irn_mode(other_different));
+       cpy = be_new_Copy(cls, birg->irg, block, temp);
+       be_node_set_flags(cpy, BE_OUT_POS(0), arch_irn_flags_dont_spill);
+
+       in[0] = irn;
+       in[1] = cpy;
+
+       /* Let the irn use the copy instead of the old other_different */
+       fix_in(irn, other_different, cpy);
+
+       /* Add the Keep resp. CopyKeep and reroute the users */
+       /* of the other_different irn in case of CopyKeep.   */
+       if (get_n_out_edges(other_different) == 0) {
+               keep = be_new_Keep(cls, birg->irg, block, 2, in);
+       }
        else {
-               proj_T = new_r_Proj(current_ir_graph, block, call, mode_T, pn_Call_T_result);
+               keep = be_new_CopyKeep_single(cls, birg->irg, block, cpy, irn, get_irn_mode(other_different));
+               be_node_set_reg_class(keep, 1, cls);
+               edges_reroute(other_different, keep, birg->irg);
        }
 
-       /* Create for each caller save register a proj (keep node argument) */
-       /* if this proj is not already present */
-       for (i = 0; i < arch_isa_get_n_reg_class(isa); i++) {
+       /* after rerouting: let the copy point to the other_different irn */
+       set_irn_n(cpy, 0, other_different);
 
-               /* reset the keep input, as we need one keep for each register class */
-               memset(in_keep, 0, set_size * sizeof(ir_node *));
-               keep_arity = 0;
-               reg_class  = arch_isa_get_reg_class(isa, i);
+       DBG((mod, LEVEL_1, "created %+F for %+F to assure should_be_different\n", keep, irn));
+}
 
-               for (j = 0; j < arch_register_class_n_regs(reg_class); j++) {
-                       reg = arch_register_for_index(reg_class, j);
+/**
+ * Checks if node has a should_be_different constraint in output
+ * and adds a Keep then to assure the constraint.
+ */
+static void assure_different_constraints(ir_node *irn, be_irg_t *birg) {
+       const arch_env_t          *arch_env = birg->main_env->arch_env;
+       const arch_register_req_t *req;
+       arch_register_req_t        req_temp;
+       int i, n;
 
-                       /* only check caller save registers */
-                       if (arch_register_type_is(reg, caller_saved)) {
-                               pn = isa->impl->get_projnum_for_register(isa, reg);
-                               if (!bitset_is_set(proj_set, pn)) {
-                                       ir_node *proj = new_r_Proj(current_ir_graph, block, (ir_node *)proj_T, mode_Is, pn);
+       req = arch_get_register_req(arch_env, &req_temp, irn, -1);
 
-                                       in_keep[keep_arity++] = proj;
-                               }
-                       }
+       if (req) {
+               if (arch_register_req_is(req, should_be_different)) {
+                       gen_assure_different_pattern(irn, birg, req->other_different);
                }
-
-               /* ok, we found some caller save register which are not in use but must be saved */
-               if (keep_arity) {
-                       be_new_Keep(reg_class, current_ir_graph, block, keep_arity, in_keep);
+               else if (arch_register_req_is(req, should_be_different_from_all)) {
+                       n = get_irn_arity(belower_skip_proj(irn));
+                       for (i = 0; i < n; i++) {
+                               gen_assure_different_pattern(irn, birg, get_irn_n(belower_skip_proj(irn), i));
+                       }
                }
        }
-
-       bitset_free(proj_set);
-       return;
 }
 
 
 
 /**
- * Calls the backend code generator functions to lower Spill and
- * Reload nodes into Store and Load. The backend is fully responsible
- * for creating the new nodes and setting their input correct.
- * Note: The caller of this has to make sure that irn is a Spill
- *       or Reload!
+ * Calls the functions to assure register constraints.
  *
- * @param irn      The Spill/Reload node
+ * @param irn      The node to be checked for lowering
  * @param walk_env The walker environment
  */
-static void lower_spill_reload(ir_node *irn, void *walk_env) {
-       lower_env_t           *env  = walk_env;
-       arch_code_generator_t *cg   = env->chord_env->main_env->cg;
-       const arch_env_t      *aenv = env->chord_env->main_env->arch_env;
-       ir_node               *res  = NULL;
-       ir_node               *sched_point;
-
-       if (be_is_Spill(irn) && cg->impl->lower_spill) {
-               res = cg->impl->lower_spill(cg, irn);
-       }
-       else if (be_is_Reload(irn) && cg->impl->lower_reload) {
-               res = cg->impl->lower_reload(cg, irn);
-               if (res && res != irn) {
-                       /* copy the result register from the reload to the load */
-                       arch_set_irn_register(aenv, res, arch_get_irn_register(aenv, irn));
-               }
-       }
+static void assure_constraints_walker(ir_node *irn, void *walk_env) {
+       if (is_Block(irn))
+               return;
 
-       if (res && res != irn) {
-               sched_point = sched_prev(irn);
-               sched_remove(irn);
-               exchange(irn, res);
-               sched_add_after(sched_point, res);
-       }
-       else {
-               DBG((env->dbg_module, LEVEL_1, "node %+F not lowered\n", irn));
-       }
+       if (mode_is_datab(get_irn_mode(irn)))
+               assure_different_constraints(irn, walk_env);
 
        return;
 }
 
 
+
 /**
- * Calls the corresponding lowering function for the node.
+ * Walks over all nodes to assure register constraints.
  *
- * @param irn      The node to be checked for lowering
- * @param walk_env The walker environment
+ * @param birg  The birg structure containing the irg
  */
-static void lower_nodes_before_sched_walker(ir_node *irn, const void *walk_env) {
-       const arch_env_t *arch_env = walk_env;
-
-       if (!is_Block(irn) && !is_Proj(irn)) {
-               if (is_Call(arch_env, irn)) {
-                       lower_call_node(irn, walk_env);
-               }
-       }
-
-       return;
+void assure_constraints(be_irg_t *birg) {
+       irg_walk_blkwise_graph(birg->irg, NULL, assure_constraints_walker, birg);
 }
 
 
+
 /**
  * Calls the corresponding lowering function for the node.
  *
@@ -570,15 +610,12 @@ static void lower_nodes_before_sched_walker(ir_node *irn, const void *walk_env)
  */
 static void lower_nodes_after_ra_walker(ir_node *irn, void *walk_env) {
        lower_env_t      *env      = walk_env;
-       const arch_env_t *arch_env = env->chord_env->main_env->arch_env;
+       const arch_env_t *arch_env = env->chord_env->birg->main_env->arch_env;
 
        if (!is_Block(irn) && !is_Proj(irn)) {
                if (is_Perm(arch_env, irn)) {
                        lower_perm_node(irn, walk_env);
                }
-               else if (be_is_Spill(irn) || be_is_Reload(irn)) {
-                       lower_spill_reload(irn, walk_env);
-               }
        }
 
        return;
@@ -586,22 +623,9 @@ static void lower_nodes_after_ra_walker(ir_node *irn, void *walk_env) {
 
 
 
-/**
- * Walks over all blocks in an irg and performs lowering need
- * to be done before scheduling (e.g. call lowering).
- *
- * @param chord_env The chordal environment containing the irg
- * @param do_copy   1 == resolve cycles with a free reg if available
- */
-void lower_nodes_before_sched(ir_graph *irg, const void *env) {
-       irg_walk_blkwise_graph(irg, NULL, lower_nodes_before_sched_walker, env);
-}
-
-
-
 /**
  * Walks over all blocks in an irg and performs lowering need to be
- * done after register allocation (e.g. perm and spill/reload lowering).
+ * done after register allocation (e.g. perm lowering).
  *
  * @param chord_env The chordal environment containing the irg
  * @param do_copy   1 == resolve cycles with a free reg if available
@@ -611,7 +635,7 @@ void lower_nodes_after_ra(be_chordal_env_t *chord_env, int do_copy) {
 
        env.chord_env  = chord_env;
        env.do_copy    = do_copy;
-       env.dbg_module = firm_dbg_register("ir.be.lower");
+       env.dbg_module = firm_dbg_register("firm.be.lower");
 
        irg_walk_blkwise_graph(chord_env->irg, NULL, lower_nodes_after_ra_walker, &env);
 }