[PATCH 15/21]middle-end: [RFC] conditionally support forcing final edge for debugging

[Tamar Christina]

Hi All,

What do people think about having the ability to force only the latch connected
exit as the exit as a param? I.e. what's in the patch but as a param.

I found this useful when debugging large example failures as it tells me where
I should be looking.  No hard requirement but just figured I'd ask if we should.

Thanks,
Tamar

gcc/ChangeLog:

        * tree-vect-loop.cc (vec_init_loop_exit_info): Allow forcing of exit.

--- inline copy of patch -- 
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 
27ab6abfa854f14f8a4cf3d9fcb1ac1c203a4198..d6b35372623e94e02965510ab557cb568c302ebe
 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -964,6 +964,7 @@ vec_init_loop_exit_info (class loop *loop)
   if (exits.length () == 1)
     return exits[0];
 
+#if 0
   /* If we have multiple exits we only support counting IV at the moment.  
Analyze
      all exits and return one */
   class tree_niter_desc niter_desc;
@@ -982,6 +983,16 @@ vec_init_loop_exit_info (class loop *loop)
     }
 
   return candidate;
+#else
+  basic_block bb = ip_normal_pos (loop);
+  if (!bb)
+    return NULL;
+
+  edge exit = EDGE_SUCC (bb, 0);
+  if (exit->dest == loop->latch)
+    return EDGE_SUCC (bb, 1);
+  return exit;
+#endif
 }
 
 /* Function bb_in_loop_p




-- 

diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 
27ab6abfa854f14f8a4cf3d9fcb1ac1c203a4198..d6b35372623e94e02965510ab557cb568c302ebe
 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -964,6 +964,7 @@ vec_init_loop_exit_info (class loop *loop)
   if (exits.length () == 1)
     return exits[0];
 
+#if 0
   /* If we have multiple exits we only support counting IV at the moment.  
Analyze
      all exits and return one */
   class tree_niter_desc niter_desc;
@@ -982,6 +983,16 @@ vec_init_loop_exit_info (class loop *loop)
     }
 
   return candidate;
+#else
+  basic_block bb = ip_normal_pos (loop);
+  if (!bb)
+    return NULL;
+
+  edge exit = EDGE_SUCC (bb, 0);
+  if (exit->dest == loop->latch)
+    return EDGE_SUCC (bb, 1);
+  return exit;
+#endif
 }
 
 /* Function bb_in_loop_p