Make warning about registers assigned to Phi inputs more clear.
[libfirm] / ir / be / bepeephole.c
index b31a820..1afc7ed 100644 (file)
@@ -32,6 +32,7 @@
 #include "iredges_t.h"
 #include "irgwalk.h"
 #include "irprintf.h"
+#include "ircons.h"
 #include "irgmod.h"
 #include "error.h"
 
@@ -61,7 +62,7 @@ static void clear_reg_value(ir_node *node)
 
        reg     = arch_get_irn_register(arch_env, node);
        if(reg == NULL) {
-               panic("No register assigned at %+F\n", node);
+               panic("No register assigned at %+F", node);
        }
        if(arch_register_type_is(reg, virtual))
                return;
@@ -86,7 +87,7 @@ static void set_reg_value(ir_node *node)
 
        reg = arch_get_irn_register(arch_env, node);
        if(reg == NULL) {
-               panic("No register assigned at %+F\n", node);
+               panic("No register assigned at %+F", node);
        }
        if(arch_register_type_is(reg, virtual))
                return;
@@ -124,6 +125,19 @@ static void set_uses(ir_node *node)
        }
 }
 
+void be_peephole_new_node(ir_node * nw)
+{
+       be_liveness_introduce(lv, nw);
+}
+
+/**
+ * must be called from peephole optimisations before a node will be killed
+ * and its users will be redirected to new_node.
+ * so bepeephole can update it's internal state.
+ *
+ * Note: killing a node and rewiring os only allowed if new_node produces
+ * the same registers as old_node.
+ */
 void be_peephole_before_exchange(const ir_node *old_node, ir_node *new_node)
 {
        const arch_register_t       *reg;
@@ -131,39 +145,47 @@ void be_peephole_before_exchange(const ir_node *old_node, ir_node *new_node)
        unsigned                     reg_idx;
        unsigned                     cls_idx;
 
-       DBG((dbg, LEVEL_1, "About to exchange %+F with %+F\n", old_node, new_node));
+       DBG((dbg, LEVEL_1, "About to exchange and kill %+F with %+F\n", old_node, new_node));
 
-       if(old_node == current_node) {
-               if(is_Proj(new_node)) {
-                       current_node = get_Proj_pred(new_node);
-               } else {
-                       current_node = new_node;
-               }
+       if (current_node == old_node) {
+               /* next node to be processed will be killed. Its scheduling predecessor
+                * must be processed next. */
+               current_node = sched_next(current_node);
+               assert (!is_Bad(current_node));
        }
 
-       if(!mode_is_data(get_irn_mode(old_node)))
+       if (!mode_is_data(get_irn_mode(old_node)))
                return;
 
        reg = arch_get_irn_register(arch_env, old_node);
-       if(reg == NULL) {
-               panic("No register assigned at %+F\n", old_node);
+       if (reg == NULL) {
+               panic("No register assigned at %+F", old_node);
        }
+       assert(reg == arch_get_irn_register(arch_env, new_node) &&
+             "KILLING a node and replacing by different register is not allowed");
+
        cls     = arch_register_get_class(reg);
        reg_idx = arch_register_get_index(reg);
        cls_idx = arch_register_class_index(cls);
 
-       if(register_values[cls_idx][reg_idx] == old_node) {
+       if (register_values[cls_idx][reg_idx] == old_node) {
                register_values[cls_idx][reg_idx] = new_node;
        }
 
        be_liveness_remove(lv, old_node);
 }
 
-void be_peephole_after_exchange(ir_node *new_node)
+void be_peephole_exchange(ir_node *old, ir_node *nw)
 {
-       be_liveness_introduce(lv, new_node);
+       be_peephole_before_exchange(old, nw);
+       sched_remove(old);
+       exchange(old, nw);
+       be_peephole_new_node(nw);
 }
 
+/**
+ * block-walker: run peephole optimization on the given block.
+ */
 static void process_block(ir_node *block, void *data)
 {
        unsigned n_classes;
@@ -192,29 +214,45 @@ static void process_block(ir_node *block, void *data)
        for( ; !sched_is_begin(current_node);
                        current_node = sched_prev(current_node)) {
                ir_op             *op;
-               ir_node           *last;
-               peephole_opt_func  func;
+               peephole_opt_func  peephole_node;
 
-               if(is_Phi(current_node))
+               assert(!is_Bad(current_node));
+               if (is_Phi(current_node))
                        break;
 
                clear_defs(current_node);
                set_uses(current_node);
 
-               op   = get_irn_op(current_node);
-               func = (peephole_opt_func) op->ops.generic;
-               if(func == NULL)
+               op            = get_irn_op(current_node);
+               peephole_node = (peephole_opt_func)op->ops.generic;
+               if (peephole_node == NULL)
                        continue;
 
-               last = current_node;
-               func(current_node);
-               /* was the current node replaced? */
-               if(current_node != last) {
-                       set_uses(current_node);
-               }
+               peephole_node(current_node);
+               assert(!is_Bad(current_node));
        }
 }
 
+static void kill_node_and_preds(ir_node *node)
+{
+       int arity, i;
+
+       arity = get_irn_arity(node);
+       for (i = 0; i < arity; ++i) {
+               ir_node *pred = get_irn_n(node, i);
+
+               set_irn_n(node, i, new_Bad());
+               if (get_irn_n_edges(pred) != 0)
+                       continue;
+
+               kill_node_and_preds(pred);
+       }
+
+       if (!is_Proj(node))
+               sched_remove(node);
+       kill_node(node);
+}
+
 /**
  * Walk through the block schedule and skip all barrier nodes.
  */
@@ -222,21 +260,22 @@ static void skip_barrier(ir_node *ret_blk, ir_graph *irg) {
        ir_node *irn;
 
        sched_foreach_reverse(ret_blk, irn) {
-               if (be_is_Barrier(irn)) {
-                       const ir_edge_t *edge, *next;
-
-                       foreach_out_edge_safe(irn, edge, next) {
-                               ir_node *proj = get_edge_src_irn(edge);
-                               int      pn   = (int)get_Proj_proj(proj);
-                               ir_node *pred = get_irn_n(irn, pn);
-
-                               edges_reroute_kind(proj, pred, EDGE_KIND_NORMAL, irg);
-                               edges_reroute_kind(proj, pred, EDGE_KIND_DEP, irg);
-                       }
-                       sched_remove(irn);
-                       kill_node(irn);
-                       break;
+               const ir_edge_t *edge, *next;
+
+               if (!be_is_Barrier(irn))
+                       continue;
+
+               foreach_out_edge_safe(irn, edge, next) {
+                       ir_node *proj = get_edge_src_irn(edge);
+                       int      pn   = (int)get_Proj_proj(proj);
+                       ir_node *pred = get_irn_n(irn, pn);
+
+                       edges_reroute_kind(proj, pred, EDGE_KIND_NORMAL, irg);
+                       edges_reroute_kind(proj, pred, EDGE_KIND_DEP, irg);
                }
+
+               kill_node_and_preds(irn);
+               break;
        }
 }
 
@@ -301,15 +340,7 @@ ir_node *be_peephole_IncSP_IncSP(ir_node *node)
        /* add node offset to pred and remove our IncSP */
        be_set_IncSP_offset(pred, offs);
 
-       be_peephole_before_exchange(node, pred);
-
-       /* rewire dependency/data edges */
-       edges_reroute_kind(node, pred, EDGE_KIND_DEP, current_ir_graph);
-       edges_reroute(node, pred, current_ir_graph);
-       sched_remove(node);
-       be_kill_node(node);
-
-       be_peephole_after_exchange(pred);
+       be_peephole_exchange(node, pred);
        return pred;
 }
 
@@ -352,4 +383,4 @@ void be_init_peephole(void)
        FIRM_DBG_REGISTER(dbg, "firm.be.peephole");
 }
 
-BE_REGISTER_MODULE_CONSTRUCTOR(be_init_spillbelady);
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_peephole);