OpenJDK / amber / amber
changeset 56052:1a5305f51bfd
8223138: Small clean-up in loop-tree support.
Summary: Rename predicate 'is_inner()' to 'is_innermost()' to be accurate. Added 'is_root()' predicate for root parent test in loop-tree. Changed definition of 'is_loop()' to always lazy-read the tail, since it should never be NULL. Cleanup of 'tail()' definition.
Reviewed-by: vlivanov, neliasso
| author | phedlin |
|---|---|
| date | Thu, 02 May 2019 11:05:47 +0200 |
| parents | 3ebf58dbf5d8 |
| children | d6f55ea4e325 |
| files | src/hotspot/share/opto/loopTransform.cpp src/hotspot/share/opto/loopnode.cpp src/hotspot/share/opto/loopnode.hpp |
| diffstat | 3 files changed, 18 insertions(+), 26 deletions(-) [+] |
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--- a/src/hotspot/share/opto/loopTransform.cpp Wed Apr 17 14:52:25 2019 +0200 +++ b/src/hotspot/share/opto/loopTransform.cpp Thu May 02 11:05:47 2019 +0200 @@ -3249,25 +3249,18 @@ // Clean out prior deadwood DCE_loop_body(); - // Look for loop-exit tests with my 50/50 guesses from the Parsing stage. // Replace with a 1-in-10 exit guess. - if (_parent /*not the root loop*/ && - !_irreducible && - // Also ignore the occasional dead backedge - !tail()->is_top()) { + if (!is_root() && is_loop()) { adjust_loop_exit_prob(phase); } - // Gate unrolling, RCE and peeling efforts. - if (!_child && // If not an inner loop, do not split - !_irreducible && - _allow_optimizations && - !tail()->is_top()) { // Also ignore the occasional dead backedge + // Unrolling, RCE and peeling efforts, iff innermost loop. + if (_allow_optimizations && is_innermost()) { if (!_has_call) { - if (!iteration_split_impl(phase, old_new)) { - return false; - } + if (!iteration_split_impl(phase, old_new)) { + return false; + } } else if (policy_unswitching(phase)) { phase->do_unswitching(this, old_new); } @@ -3540,7 +3533,7 @@ bool PhaseIdealLoop::intrinsify_fill(IdealLoopTree* lpt) { // Only for counted inner loops - if (!lpt->is_counted() || !lpt->is_inner()) { + if (!lpt->is_counted() || !lpt->is_innermost()) { return false; }
--- a/src/hotspot/share/opto/loopnode.cpp Wed Apr 17 14:52:25 2019 +0200 +++ b/src/hotspot/share/opto/loopnode.cpp Thu May 02 11:05:47 2019 +0200 @@ -2946,7 +2946,7 @@ for (LoopTreeIterator iter(_ltree_root); !iter.done(); iter.next()) { IdealLoopTree* lpt = iter.current(); bool is_counted = lpt->is_counted(); - if (!is_counted || !lpt->is_inner()) continue; + if (!is_counted || !lpt->is_innermost()) continue; // check for vectorized loops, any reassociation of invariants was already done if (is_counted && lpt->_head->as_CountedLoop()->is_unroll_only()) continue;
--- a/src/hotspot/share/opto/loopnode.hpp Wed Apr 17 14:52:25 2019 +0200 +++ b/src/hotspot/share/opto/loopnode.hpp Thu May 02 11:05:47 2019 +0200 @@ -615,9 +615,11 @@ // Put loop body on igvn work list void record_for_igvn(); - bool is_loop() { return !_irreducible && _tail && !_tail->is_top(); } - bool is_inner() { return is_loop() && _child == NULL; } - bool is_counted() { return is_loop() && _head != NULL && _head->is_CountedLoop(); } + bool is_root() { return _parent == NULL; } + // A proper/reducible loop w/o any (occasional) dead back-edge. + bool is_loop() { return !_irreducible && !tail()->is_top(); } + bool is_counted() { return is_loop() && _head->is_CountedLoop(); } + bool is_innermost() { return is_loop() && _child == NULL; } void remove_main_post_loops(CountedLoopNode *cl, PhaseIdealLoop *phase); @@ -1410,14 +1412,11 @@ };// class CountedLoopReserveKit inline Node* IdealLoopTree::tail() { -// Handle lazy update of _tail field - Node *n = _tail; - //while( !n->in(0) ) // Skip dead CFG nodes - //n = n->in(1); - if (n->in(0) == NULL) - n = _phase->get_ctrl(n); - _tail = n; - return n; + // Handle lazy update of _tail field. + if (_tail->in(0) == NULL) { + _tail = _phase->get_ctrl(_tail); + } + return _tail; }