8261914: IfNode::fold_compares_helper faces non-canonicalized bool when running JRuby JSON workload #2707
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| return false; | ||
| } | ||
| assert(this_bool->_test.is_less() && !fail->_con, "incorrect test"); |
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This should lead with "this test was canonicalized" comment? Missed during the move, I think.
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I also find it a bit weird to even have the assert on this path, as we tested all cases in the if-chain before, and the only path to this assert is through lt and le -- which is is_less? Maybe I am missing something, though.
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I also find it a bit weird to even have the assert on this path, as we tested all cases in the if-chain before, and the only path to this assert is through
ltandle-- which isis_less? Maybe I am missing something, though.
I kept it because of the !fail->_con part of the assert. I kept the whole assert and move it around because I'm lazy, I guess.
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That's fine. Keep the comment, though?
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The assert fires because the current IfNode's condition was not
canonicalized when it's being folded with a dominating
IfNode. idealize_test() should have taken care of that because it
executed before fold_compares() but it didn't because:
Node* new_b = phase->transform( new BoolNode(b->in(1), bt.negate()) );
if( !new_b->is_Bool() ) return NULL;
caused it to bail out. new_b is a constant. This happens because of
the order in which nodes are processed by IGVN. The If's current Bool
would also constant fold but it's in the IGVN worklist and hasn't been
processed yet.
The fix I propose is to keep Aleksey's defensive fix but to check that
the Bool input is indeed about to be transformed by IGVN and that that
would cause the IfNode to be reprocessed.
I tried to write a test case but didn't succeed. The 2 If nodes come
from a tableswitch that's transformed into a series of If based on
profile data. I couldn't reproduce the profile data with a simple test
case.
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$ git fetch https://git.openjdk.java.net/jdk pull/2707/head:pull/2707$ git checkout pull/2707