OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Resolve complicated join nodes in range_from_dom.

Browse Source 
Join nodes which carry outgoing ranges on incoming edges are uncommon,
but can still be resolved by setting the dominator range, and then
calculating incoming edges.  Avoid doing so if one of the incoing edges
is not dominated by the same dominator.

	* gimple-range-cache.cc (ranger_cache::range_from_dom): Check
	  for incoming ranges on join nodes and add to worklist.
This commit is contained in:
Andrew MacLeod 2022-07-18 15:04:23 -04:00
parent b0cc57cd76
commit dbb093f4f1
1 changed files with 26 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
gcc/gimple-range-cache.cc
View File

@ -1384,6 +1384,32 @@ ranger_cache::range_from_dom (vrange &r, tree name, basic_block start_bb,
// This block has an outgoing range.
if (m_gori.has_edge_range_p (name, bb))
m_workback.quick_push (prev_bb);
else
{
// Normally join blocks don't carry any new range information on
// incoming edges. If the first incoming edge to this block does
// generate a range, calculate the ranges if all incoming edges
// are also dominated by the dominator. (Avoids backedges which
// will break the rule of moving only upward in the domniator tree).
// If the first pred does not generate a range, then we will be
// using the dominator range anyway, so thats all the check needed.
if (EDGE_COUNT (prev_bb->preds) > 1
&& m_gori.has_edge_range_p (name, EDGE_PRED (prev_bb, 0)->src))
{
edge e;
edge_iterator ei;
bool all_dom = true;
FOR_EACH_EDGE (e, ei, prev_bb->preds)
if (e->src != bb
&& !dominated_by_p (CDI_DOMINATORS, e->src, bb))
{
all_dom = false;
break;
}
if (all_dom)
m_workback.quick_push (prev_bb);
}
}
if (def_bb == bb)
break;