Update the liveness of the *operands* when fixing flags users (why is liveness active...
[libfirm] / ir / be / beflags.c
index 1cde407..6537ac7 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1995-2007 University of Karlsruhe.  All right reserved.
+ * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
  *
  * This file is part of libFirm.
  *
 #include "bearch_t.h"
 #include "beirg_t.h"
 #include "besched_t.h"
+#include "benode_t.h"
 
 static const arch_env_t            *arch_env   = NULL;
 static const arch_register_class_t *flag_class = NULL;
 static const arch_register_t       *flags_reg  = NULL;
 static func_rematerialize           remat      = NULL;
+static int                          changed;
 
 static ir_node *default_remat(ir_node *node, ir_node *after)
 {
-       ir_node *block;
+       ir_node *block, *copy;
        if(is_Block(after))
                block = after;
        else
                block = get_nodes_block(after);
 
-       ir_node *copy = exact_copy(node);
+       copy = exact_copy(node);
        set_nodes_block(copy, block);
        sched_add_after(after, copy);
 
@@ -95,7 +97,19 @@ static int can_move(ir_node *node, ir_node *after)
                                /* phi represents a usage at block end */
                                if(is_Phi(out2))
                                        continue;
-                               if(sched_get_time_step(out2) <= sched_get_time_step(after)) {
+                               if(is_Sync(out2)) {
+                                       const ir_edge_t *edge3;
+                                       foreach_out_edge(out2, edge3) {
+                                               ir_node *out3 = get_edge_src_irn(edge3);
+                                               /* phi represents a usage at block end */
+                                               if(is_Phi(out3))
+                                                       continue;
+                                               assert(!is_Sync(out3));
+                                               if(sched_get_time_step(out3) <= sched_get_time_step(after)) {
+                                                       return 0;
+                                               }
+                                       }
+                               } else if(sched_get_time_step(out2) <= sched_get_time_step(after)) {
                                        return 0;
                                }
                        }
@@ -113,7 +127,7 @@ static int can_move(ir_node *node, ir_node *after)
 }
 
 static void rematerialize_or_move(ir_node *flags_needed, ir_node *node,
-                                  ir_node *flag_consumers, int pn)
+                                  ir_node *flag_consumers, int pn, be_lv_t *lv)
 {
        ir_node *n;
        ir_node *copy;
@@ -125,12 +139,12 @@ static void rematerialize_or_move(ir_node *flags_needed, ir_node *node,
                /* move it */
                sched_remove(flags_needed);
                sched_add_after(node, flags_needed);
-               ir_fprintf(stderr, "Move node %+F after node %+F\n", flags_needed, node);
+               /* No need to update liveness, because the node stays in the same block */
                return;
        }
 
-       copy = remat(flags_needed, node);
-       ir_fprintf(stderr, "Remat node %+F after node %+F\n", flags_needed, node);
+       changed = 1;
+       copy    = remat(flags_needed, node);
 
        if(get_irn_mode(copy) == mode_T) {
                ir_node *block = get_nodes_block(copy);
@@ -155,6 +169,36 @@ static void rematerialize_or_move(ir_node *flags_needed, ir_node *node,
                }
                n = get_irn_link(n);
        } while(n != NULL);
+
+       /* No need to introduce the copy, because it only lives in this block, but
+        * we have to update the liveness of all operands */
+       if (is_Block(node) ||
+                       get_nodes_block(node) != get_nodes_block(flags_needed)) {
+               int i;
+
+               for (i = get_irn_arity(copy); i >= 0; --i) {
+                       be_liveness_update(lv, get_irn_n(copy, i));
+               }
+       }
+}
+
+static int is_modify_flags(ir_node *node) {
+       int i, arity;
+
+       if(arch_irn_is(arch_env, node, modify_flags))
+               return 1;
+       if(!be_is_Keep(node))
+               return 0;
+
+       arity = get_irn_arity(node);
+       for(i = 0; i < arity; ++i) {
+               ir_node *in = get_irn_n(node, i);
+               in = skip_Proj(in);
+               if(arch_irn_is(arch_env, in, modify_flags))
+                       return 1;
+       }
+
+       return 0;
 }
 
 /**
@@ -169,31 +213,32 @@ static void fix_flags_walker(ir_node *block, void *env)
        ir_node *node;
        ir_node *flags_needed   = NULL;
        ir_node *flag_consumers = NULL;
-       int      pn;
-       (void) env;
+       int      pn = -1;
 
        sched_foreach_reverse(block, node) {
                int i, arity;
                ir_node *new_flags_needed = NULL;
 
+               if(is_Phi(node))
+                       break;
+
                if(node == flags_needed) {
                        /* all ok */
                        flags_needed   = NULL;
                        flag_consumers = NULL;
                }
 
-               /* test wether node destroys the flags */
-               if(flags_needed != NULL && arch_irn_is(arch_env, node, modify_flags)) {
+               /* test whether node destroys the flags */
+               if(flags_needed != NULL && is_modify_flags(node)) {
                        /* rematerialize */
-                       rematerialize_or_move(flags_needed, node, flag_consumers, pn);
+                       rematerialize_or_move(flags_needed, node, flag_consumers, pn, env);
                        flags_needed   = NULL;
                        flag_consumers = NULL;
                }
 
-               /* test wether the current node needs flags */
+               /* test whether the current node needs flags */
                arity = get_irn_arity(node);
                for(i = 0; i < arity; ++i) {
-                       //ir_node *in = get_irn_n(node, i);
                        const arch_register_class_t *cls
                                = arch_get_irn_reg_class(arch_env, node, i);
                        if(cls == flag_class) {
@@ -207,16 +252,17 @@ static void fix_flags_walker(ir_node *block, void *env)
 
                /* spiller can't (correctly) remat flag consumers at the moment */
                assert(!arch_irn_is(arch_env, node, rematerializable));
-               if(new_flags_needed != flags_needed) {
+
+               if(skip_Proj(new_flags_needed) != flags_needed) {
                        if(flags_needed != NULL) {
                                /* rematerialize node */
-                               rematerialize_or_move(flags_needed, node, flag_consumers, pn);
+                               rematerialize_or_move(flags_needed, node, flag_consumers, pn, env);
                                flags_needed   = NULL;
                                flag_consumers = NULL;
                        }
 
                        flags_needed = new_flags_needed;
-                                       arch_set_irn_register(arch_env, flags_needed, flags_reg);
+                       arch_set_irn_register(arch_env, flags_needed, flags_reg);
                        if(is_Proj(flags_needed)) {
                                pn           = get_Proj_proj(flags_needed);
                                flags_needed = get_Proj_pred(flags_needed);
@@ -226,14 +272,14 @@ static void fix_flags_walker(ir_node *block, void *env)
                        assert(arch_irn_is(arch_env, flags_needed, rematerializable));
                } else {
                        /* link all consumers in a list */
-                       set_irn_link(flag_consumers, node);
+                       set_irn_link(node, flag_consumers);
                        flag_consumers = node;
                }
        }
 
        if(flags_needed != NULL) {
                assert(get_nodes_block(flags_needed) != block);
-               rematerialize_or_move(flags_needed, block, flag_consumers, pn);
+               rematerialize_or_move(flags_needed, node, flag_consumers, pn, env);
                flags_needed   = NULL;
                flag_consumers = NULL;
        }
@@ -251,10 +297,15 @@ void be_sched_fix_flags(be_irg_t *birg, const arch_register_class_t *flag_cls,
        flag_class = flag_cls;
        flags_reg  = & flag_class->regs[0];
        remat      = remat_func;
+       changed    = 0;
        if(remat == NULL)
                remat = &default_remat;
 
        set_using_irn_link(irg);
-       irg_block_walk_graph(irg, fix_flags_walker, NULL, NULL);
+       irg_block_walk_graph(irg, fix_flags_walker, NULL, birg->lv);
        clear_using_irn_link(irg);
+
+       if(changed) {
+               be_remove_dead_nodes_from_schedule(birg);
+       }
 }