tree-ssa-propagate.c (add_ssa_edge): Dump what edge list we add which use to.

2015-07-07  Richard Biener  <rguenther@suse.de>

	* tree-ssa-propagate.c (add_ssa_edge): Dump what edge list we
	add which use to.
	(add_control_edge): Remove excessive vertical space in dumping.
	(process_ssa_edge_worklist): Simulate at most one statement and
	return whether we did.  Do not simulate PHIs if they are in a
	BB not yet simulated.
	(ssa_propagate): Adjust to always drain the BB worklist whenever
	a BB is available there, likewise the VARYING edges list before
	the interesting edge list.

From-SVN: r225504

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d136ee1722ad0486294d97aebd22c119f2bb6314..2cff379df60cc18470da5214a51ca0751f501cfb 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2015-07-07  Richard Biener  <rguenther@suse.de>
+
+       * tree-ssa-propagate.c (add_ssa_edge): Dump what edge list we
+       add which use to.
+       (add_control_edge): Remove excessive vertical space in dumping.
+       (process_ssa_edge_worklist): Simulate at most one statement and
+       return whether we did.  Do not simulate PHIs if they are in a
+       BB not yet simulated.
+       (ssa_propagate): Adjust to always drain the BB worklist whenever
+       a BB is available there, likewise the VARYING edges list before
+       the interesting edge list.
+
 2015-07-07  Christian Bruel  <christian.bruel@st.com>
 
        PR target/52144

diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c
index c38bb281c6893ce6e41760bfaea93a6d04d3a1c0..2f6736f5724271194a2aa8e6e609efa7e0ab9ab1 100644 (file)
--- a/gcc/tree-ssa-propagate.c
+++ b/gcc/tree-ssa-propagate.c
@@ -281,9 +281,23 @@ add_ssa_edge (tree var, bool is_varying)
        {
          gimple_set_plf (use_stmt, STMT_IN_SSA_EDGE_WORKLIST, true);
          if (is_varying)
-           varying_ssa_edges.safe_push (use_stmt);
+           {
+             if (dump_file && (dump_flags & TDF_DETAILS))
+               {
+                 fprintf (dump_file, "varying_ssa_edges: adding SSA use in ");
+                 print_gimple_stmt (dump_file, use_stmt, 0, TDF_SLIM);
+               }
+             varying_ssa_edges.safe_push (use_stmt);
+           }
          else
-           interesting_ssa_edges.safe_push (use_stmt);
+           {
+             if (dump_file && (dump_flags & TDF_DETAILS))
+               {
+                 fprintf (dump_file, "interesting_ssa_edges: adding SSA use in ");
+                 print_gimple_stmt (dump_file, use_stmt, 0, TDF_SLIM);
+               }
+             interesting_ssa_edges.safe_push (use_stmt);
+           }
        }
     }
 }
@@ -311,7 +325,7 @@ add_control_edge (edge e)
   cfg_blocks_add (bb);
 
   if (dump_file && (dump_flags & TDF_DETAILS))
-    fprintf (dump_file, "\nAdding Destination of edge (%d -> %d) to worklist\n",
+    fprintf (dump_file, "Adding destination of edge (%d -> %d) to worklist\n",
        e->src->index, e->dest->index);
 }
 
@@ -414,14 +428,15 @@ simulate_stmt (gimple stmt)
 
 /* Process an SSA edge worklist.  WORKLIST is the SSA edge worklist to
    drain.  This pops statements off the given WORKLIST and processes
-   them until there are no more statements on WORKLIST.
-   We take a pointer to WORKLIST because it may be reallocated when an
-   SSA edge is added to it in simulate_stmt.  */
+   them until one statement was simulated or there are no more statements
+   on WORKLIST.  We take a pointer to WORKLIST because it may be reallocated
+   when an SSA edge is added to it in simulate_stmt.  Return true if a stmt
+   was simulated.  */
 
-static void
-process_ssa_edge_worklist (vec<gimple> *worklist)
+static bool 
+process_ssa_edge_worklist (vec<gimple> *worklist, const char *edge_list_name)
 {
-  /* Drain the entire worklist.  */
+  /* Process the next entry from the worklist.  */
   while (worklist->length () > 0)
     {
       basic_block bb;
@@ -437,21 +452,35 @@ process_ssa_edge_worklist (vec<gimple> *worklist)
       /* STMT is no longer in a worklist.  */
       gimple_set_plf (stmt, STMT_IN_SSA_EDGE_WORKLIST, false);
 
+      bb = gimple_bb (stmt);
+
+      /* Visit the statement only if its block is marked executable.
+         If it is not executable then it will be visited when we simulate
+        all statements in the block as soon as an incoming edge gets
+        marked executable.  */
+      if (!bitmap_bit_p (executable_blocks, bb->index))
+       {
+         if (dump_file && (dump_flags & TDF_DETAILS))
+           {
+             fprintf (dump_file, "\nDropping statement from SSA worklist: ");
+             print_gimple_stmt (dump_file, stmt, 0, dump_flags);
+           }
+         continue;
+       }
+
       if (dump_file && (dump_flags & TDF_DETAILS))
        {
-         fprintf (dump_file, "\nSimulating statement (from ssa_edges): ");
+         fprintf (dump_file, "\nSimulating statement (from %s): ",
+                  edge_list_name);
          print_gimple_stmt (dump_file, stmt, 0, dump_flags);
        }
 
-      bb = gimple_bb (stmt);
+      simulate_stmt (stmt);
 
-      /* PHI nodes are always visited, regardless of whether or not
-        the destination block is executable.  Otherwise, visit the
-        statement only if its block is marked executable.  */
-      if (gimple_code (stmt) == GIMPLE_PHI
-         || bitmap_bit_p (executable_blocks, bb->index))
-       simulate_stmt (stmt);
+      return true;
     }
+
+  return false;
 }
 
 
@@ -917,14 +946,17 @@ ssa_propagate (ssa_prop_visit_stmt_fn visit_stmt,
          /* Pull the next block to simulate off the worklist.  */
          basic_block dest_block = cfg_blocks_get ();
          simulate_block (dest_block);
+         continue;
        }
 
       /* In order to move things to varying as quickly as
         possible,process the VARYING_SSA_EDGES worklist first.  */
-      process_ssa_edge_worklist (&varying_ssa_edges);
+      if (process_ssa_edge_worklist (&varying_ssa_edges, "varying_ssa_edges"))
+       continue;
 
       /* Now process the INTERESTING_SSA_EDGES worklist.  */
-      process_ssa_edge_worklist (&interesting_ssa_edges);
+      process_ssa_edge_worklist (&interesting_ssa_edges,
+                                "interesting_ssa_edges");
     }
 
   ssa_prop_fini ();