PR target/42495

	PR middle-end/42574
	* basic-block.h (get_dominated_to_depth): Declare.
	* dominance.c (get_dominated_to_depth): New function, use
	get_all_dominated_blocks as a base.
	(get_all_dominated_blocks): Use get_dominated_to_depth.

	* gcse.c (occr_t, VEC (occr_t, heap)): Define.
	(hoist_exprs): Remove.
	(alloc_code_hoist_mem, free_code_hoist_mem): Update.
	(compute_code_hoist_vbeinout): Add debug print outs.
	(hoist_code): Partially rewrite, simplify.  Use get_dominated_to_depth.

	* params.def (PARAM_MAX_HOIST_DEPTH): New parameter to avoid
	quadratic behavior.
	* params.h (MAX_HOIST_DEPTH): New macro.
	* doc/invoke.texi (max-hoist-depth): Document.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@162597 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 19 insertions, 3 deletions

diff --git a/gcc/dominance.c b/gcc/dominance.c
index 2e5f3ee26a2..688c87bff43 100644
--- a/gcc/dominance.c
+++ b/gcc/dominance.c
@@ -784,16 +784,20 @@ get_dominated_by_region (enum cdi_direction dir, basic_block *region,
 }
 
 /* Returns the list of basic blocks including BB dominated by BB, in the
-   direction DIR.  The vector will be sorted in preorder.  */
+   direction DIR up to DEPTH in the dominator tree.  The DEPTH of zero will
+   produce a vector containing all dominated blocks.  The vector will be sorted
+   in preorder.  */
 
 VEC (basic_block, heap) *
-get_all_dominated_blocks (enum cdi_direction dir, basic_block bb)
+get_dominated_to_depth (enum cdi_direction dir, basic_block bb, int depth)
 {
   VEC(basic_block, heap) *bbs = NULL;
   unsigned i;
+  unsigned next_level_start;
 
   i = 0;
   VEC_safe_push (basic_block, heap, bbs, bb);
+  next_level_start = 1; /* = VEC_length (basic_block, bbs); */
 
   do
     {
@@ -804,12 +808,24 @@ get_all_dominated_blocks (enum cdi_direction dir, basic_block bb)
 	   son;
 	   son = next_dom_son (dir, son))
 	VEC_safe_push (basic_block, heap, bbs, son);
+
+      if (i == next_level_start && --depth)
+	next_level_start = VEC_length (basic_block, bbs);
     }
-  while (i < VEC_length (basic_block, bbs));
+  while (i < next_level_start);
 
   return bbs;
 }
 
+/* Returns the list of basic blocks including BB dominated by BB, in the
+   direction DIR.  The vector will be sorted in preorder.  */
+
+VEC (basic_block, heap) *
+get_all_dominated_blocks (enum cdi_direction dir, basic_block bb)
+{
+  return get_dominated_to_depth (dir, bb, 0);
+}
+
 /* Redirect all edges pointing to BB to TO.  */
 void
 redirect_immediate_dominators (enum cdi_direction dir, basic_block bb,