archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-16 09:04:41 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

7042327: assert(opaq->outcnt() == 1 && opaq->in(1) == limit)

Browse source 
Separate limit by Opaque2 node when calculating new limit for unrolled loop.

Reviewed-by: never
This commit is contained in:
Vladimir Kozlov 2011-05-05 21:06:14 -07:00
parent 9f0bca3b75
commit 8698030a91
2 changed files with 25 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

40
hotspot/src/share/vm/opto/loopTransform.cpp
View file

@ -1229,6 +1229,19 @@ void PhaseIdealLoop::do_unroll( IdealLoopTree *loop, Node_List &old_new, bool ad
new_limit = _igvn.intcon(limit->get_int() - stride_con);
set_ctrl(new_limit, C->root());
} else {
// Limit is not constant.
{
// Separate limit by Opaque node in case it is an incremented
// variable from previous loop to avoid using pre-incremented
// value which could increase register pressure.
// Otherwise reorg_offsets() optimization will create a separate
// Opaque node for each use of trip-counter and as result
// zero trip guard limit will be different from loop limit.
assert(has_ctrl(opaq), "should have it");
Node* opaq_ctrl = get_ctrl(opaq);
limit = new (C, 2) Opaque2Node( C, limit );
register_new_node( limit, opaq_ctrl );
}
if (stride_con > 0 && ((limit_type->_lo - stride_con) < limit_type->_lo) ||
stride_con < 0 && ((limit_type->_hi - stride_con) > limit_type->_hi)) {
// No underflow.
@ -1278,24 +1291,19 @@ void PhaseIdealLoop::do_unroll( IdealLoopTree *loop, Node_List &old_new, bool ad
register_new_node(new_limit, ctrl);
}
assert(new_limit != NULL, "");
if (limit->outcnt() == 2) {
// Replace old limit if it is used only in loop tests.
_igvn.replace_node(limit, new_limit);
} else {
// Replace in loop test.
_igvn.hash_delete(cmp);
cmp->set_req(2, new_limit);
// Replace in loop test.
_igvn.hash_delete(cmp);
cmp->set_req(2, new_limit);
// Step 3: Find the min-trip test guaranteed before a 'main' loop.
// Make it a 1-trip test (means at least 2 trips).
// Step 3: Find the min-trip test guaranteed before a 'main' loop.
// Make it a 1-trip test (means at least 2 trips).
// Guard test uses an 'opaque' node which is not shared. Hence I
// can edit it's inputs directly. Hammer in the new limit for the
// minimum-trip guard.
assert(opaq->outcnt() == 1, "");
_igvn.hash_delete(opaq);
opaq->set_req(1, new_limit);
}
// Guard test uses an 'opaque' node which is not shared. Hence I
// can edit it's inputs directly. Hammer in the new limit for the
// minimum-trip guard.
assert(opaq->outcnt() == 1, "");
_igvn.hash_delete(opaq);
opaq->set_req(1, new_limit);
}
// Adjust max trip count. The trip count is intentionally rounded