*** empty log message ***

[libfirm] / ir / ir / ircons.c

diff --git a/ir/ir/ircons.c b/ir/ir/ircons.c
index 3362748..885e006 100644 (file)
--- a/ir/ir/ircons.c
+++ b/ir/ir/ircons.c
@@ -4,7 +4,7 @@
 ** Authors: Martin Trapp, Christian Schaefer
 **
 ** ircons.c: basic and more detailed irnode constructors
-**           store, block and parameter administration ,
+**           store, block and parameter administration.
 ** Adapted to extended FIRM nodes (exceptions...) and commented
 **   by Goetz Lindenmaier
 */
@@ -40,7 +40,8 @@ new_r_Block (ir_graph *irg,  int arity, ir_node **in)
 {
   ir_node *res;
 
-  res = new_ir_node (current_ir_graph, NULL, op_Block, mode_R, arity, in);
+  res = new_ir_node (irg, NULL, op_Block, mode_R, arity, in);
+  set_Block_matured(res, 1);
 
   irn_vrfy (res);
   return res;
@@ -531,7 +532,12 @@ new_r_SymConst (ir_graph *irg, ir_node *block, type_or_id *value,
 {
   ir_node *in[0] = {};
   ir_node *res;
-  res = new_ir_node (irg, block, op_SymConst, mode_I, 0, in);
+  ir_mode *mode;
+  if (symkind == linkage_ptr_info)
+    mode = mode_p;
+  else
+    mode = mode_I;
+  res = new_ir_node (irg, block, op_SymConst, mode, 0, in);
 
   res->attr.i.num = symkind;
   if (symkind == linkage_ptr_info) {
@@ -657,7 +663,13 @@ new_r_Phi0 (ir_graph *irg, ir_node *block, ir_mode *mode)
   return res;
 }
 
-#if 0
+/* There are two implementations of the Phi node construction.  The first
+   is faster, but does not work for blocks with more than 2 predecessors.
+   The second works always but is slower and causes more unnecessary Phi
+   nodes.
+   Select the implementations by the following preprocessor flag set in
+   common/common.h: */
+#if USE_FAST_PHI_CONSTRUCTION
 
 /* This is a stack used for allocating and deallocating nodes in
    new_r_Phi_in.  The original implementation used the obstack
@@ -964,8 +976,10 @@ get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
     it starts the recursion.  This causes an Id at the entry of
     every block that has no definition of the value! **/
 
+#if USE_EXPICIT_PHI_IN_STACK
 /* Just a dummy */
 Phi_in_stack * new_Phi_in_stack() {  return NULL; }
+#endif
 
 inline ir_node *
 new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
@@ -978,11 +992,6 @@ new_r_Phi_in (ir_graph *irg, ir_node *block, ir_mode *mode,
      array. */
   res = new_ir_node (irg, block, op_Phi, mode, ins, in);
 
-  /* @@@GL The in-array should not contain NULLS with this algorithm.
-     Remove this test if it never is true. Just to make sure the algorithm runs. */
-  for (i=0;  i < ins;  ++i)
-    if (in[i] == NULL) assert(0);
-
   /* This loop checks whether the Phi has more than one predecessor.
      If so, it is a real Phi node and we break the loop.  Else the
      Phi node merges the same definition on several paths and therefore
@@ -1048,8 +1057,8 @@ phi_merge (ir_node *block, int pos, ir_mode *mode, ir_node **nin, int ins)
     }
   }
 
-  /* This loop goes to all predecessor blocks of the block the Phi node is in
-     and there finds the operands of the Phi node by calling
+  /* This loop goes to all predecessor blocks of the block the Phi node
+     is in and there finds the operands of the Phi node by calling
      get_r_value_internal.  */
   for (i = 1;  i <= ins;  ++i) {
     assert (block->in[i]);
@@ -1123,6 +1132,8 @@ get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
 
   /* case 4 -- already visited. */
   if (get_irn_visited(block) == get_irg_visited(current_ir_graph)) {
+    /* As phi_merge allocates a Phi0 this value is always defined. Here
+     is the critical difference of the two algorithms. */
     assert(block->attr.block.graph_arr[pos]);
     return block->attr.block.graph_arr[pos];
   }
@@ -1134,7 +1145,7 @@ get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
   res = block->attr.block.graph_arr[pos];
 
   /* case 2 -- If the value is actually computed, return it. */
-  if (res) { return res;};
+  if (res) { return res; };
 
   if (block->attr.block.matured) { /* case 3 */
 
@@ -1176,7 +1187,7 @@ get_r_value_internal (ir_node *block, int pos, ir_mode *mode)
   return res;
 }
 
-#endif /* if 0 */
+#endif /* USE_FAST_PHI_CONSTRUCTION */
 
 /****************************************************************************/