re PR debug/54693 (VTA guality issues with loops)

PR debug/54693
* tree-ssa-loop-ivopts.c (remove_unused_ivs): Emit debug temps
for dropped IV sets.

From-SVN: r193139

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ddffb1a19d415dac38f22be2c08e5d07d9b15a03..2538bfb8adc4a83681813da75819d2aefd05d333 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-04  Alexandre Oliva <aoliva@redhat.com>, Jakub Jelinek <jakub@redhat.com>
+
+       PR debug/54693
+       * tree-ssa-loop-ivopts.c (remove_unused_ivs): Emit debug temps
+       for dropped IV sets.
+
 2012-11-04  Alexandre Oliva <aoliva@redhat.com>
 
        PR debug/54693

diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index e43d40c43ce1fde28f9dbbcc240063e6b2a8e350..4837fc6681290cebc15d1f71046c6b21d01f5c86 100644 (file)
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -6422,7 +6422,111 @@ remove_unused_ivs (struct ivopts_data *data)
          && !info->inv_id
          && !info->iv->have_use_for
          && !info->preserve_biv)
-       bitmap_set_bit (toremove, SSA_NAME_VERSION (info->iv->ssa_name));
+       {
+         bitmap_set_bit (toremove, SSA_NAME_VERSION (info->iv->ssa_name));
+         
+         tree def = info->iv->ssa_name;
+
+         if (MAY_HAVE_DEBUG_STMTS && SSA_NAME_DEF_STMT (def))
+           {
+             imm_use_iterator imm_iter;
+             use_operand_p use_p;
+             gimple stmt;
+             int count = 0;
+
+             FOR_EACH_IMM_USE_STMT (stmt, imm_iter, def)
+               {
+                 if (!gimple_debug_bind_p (stmt))
+                   continue;
+
+                 /* We just want to determine whether to do nothing
+                    (count == 0), to substitute the computed
+                    expression into a single use of the SSA DEF by
+                    itself (count == 1), or to use a debug temp
+                    because the SSA DEF is used multiple times or as
+                    part of a larger expression (count > 1). */
+                 count++;
+                 if (gimple_debug_bind_get_value (stmt) != def)
+                   count++;
+
+                 if (count > 1)
+                   BREAK_FROM_IMM_USE_STMT (imm_iter);
+               }
+
+             if (!count)
+               continue;
+
+             struct iv_use dummy_use;
+             struct iv_cand *best_cand = NULL, *cand;
+             unsigned i, best_pref = 0, cand_pref;
+
+             memset (&dummy_use, 0, sizeof (dummy_use));
+             dummy_use.iv = info->iv;
+             for (i = 0; i < n_iv_uses (data) && i < 64; i++)
+               {
+                 cand = iv_use (data, i)->selected;
+                 if (cand == best_cand)
+                   continue;
+                 cand_pref = operand_equal_p (cand->iv->step,
+                                              info->iv->step, 0)
+                   ? 4 : 0;
+                 cand_pref
+                   += TYPE_MODE (TREE_TYPE (cand->iv->base))
+                   == TYPE_MODE (TREE_TYPE (info->iv->base))
+                   ? 2 : 0;
+                 cand_pref
+                   += TREE_CODE (cand->iv->base) == INTEGER_CST
+                   ? 1 : 0;
+                 if (best_cand == NULL || best_pref < cand_pref)
+                   {
+                     best_cand = cand;
+                     best_pref = cand_pref;
+                   }
+               }
+
+             if (!best_cand)
+               continue;
+
+             tree comp = get_computation_at (data->current_loop,
+                                             &dummy_use, best_cand,
+                                             SSA_NAME_DEF_STMT (def));
+             if (!comp)
+               continue;
+
+             if (count > 1)
+               {
+                 tree vexpr = make_node (DEBUG_EXPR_DECL);
+                 DECL_ARTIFICIAL (vexpr) = 1;
+                 TREE_TYPE (vexpr) = TREE_TYPE (comp);
+                 if (SSA_NAME_VAR (def))
+                   DECL_MODE (vexpr) = DECL_MODE (SSA_NAME_VAR (def));
+                 else
+                   DECL_MODE (vexpr) = TYPE_MODE (TREE_TYPE (vexpr));
+                 gimple def_temp = gimple_build_debug_bind (vexpr, comp, NULL);
+                 gimple_stmt_iterator gsi;
+
+                 if (gimple_code (SSA_NAME_DEF_STMT (def)) == GIMPLE_PHI)
+                   gsi = gsi_after_labels (gimple_bb
+                                           (SSA_NAME_DEF_STMT (def)));
+                 else
+                   gsi = gsi_for_stmt (SSA_NAME_DEF_STMT (def));
+
+                 gsi_insert_before (&gsi, def_temp, GSI_SAME_STMT);
+                 comp = vexpr;
+               }
+
+             FOR_EACH_IMM_USE_STMT (stmt, imm_iter, def)
+               {
+                 if (!gimple_debug_bind_p (stmt))
+                   continue;
+
+                 FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter)
+                   SET_USE (use_p, comp);
+
+                 update_stmt (stmt);
+               }
+           }
+       }
     }
 
   release_defs_bitset (toremove);