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8360175: C2 crash: assert(edge_from_to(prior_use,n)) failed: before block local scheduling #26157

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8360175: C2 crash: assert(edge_from_to(prior_use,n)) failed: before block local scheduling #26157

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2 changes: 1 addition & 1 deletion src/hotspot/cpu/x86/peephole_x86_64.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -346,7 +346,7 @@ bool Peephole::lea_remove_redundant(Block* block, int block_index, PhaseCFG* cfg
for (DUIterator_Fast imax, i = decode->fast_outs(imax); i < imax; i++) {
Node* dependant_lea = decode->fast_out(i);
if (dependant_lea->is_Mach() && dependant_lea->as_Mach()->ideal_Opcode() == Op_AddP) {
dependant_lea->set_req(AddPNode::Base, decode_address);
dependant_lea->set_req(AddPNode::Base, lea_derived_oop->in(AddPNode::Address));
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The fix looks reasonable to me, too. No worries about the regression test, thanks for trying! A small question: Why don't we use lea_address?

Another thing I've noticed while browsing the code: ra_ and new_root seem to be unused and could be removed (could probably also be squeezed into this PR here instead of creating a new issue just for that).

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We cannot use lea_address because in case of a spill that also gets moved up one node to check if the lea and the decode point to the same grandparent.

Another thing I've noticed while browsing the code: ra_ and new_root seem to be unused and could be removed.

These arguments come from the machinery that calls this out of the matcher. I am not too familiar with it, so my working assumption so far has been to keep the signature the same as the other peepholes, which seems logical since it is called by generated code.

// This deleted something in the out array, hence adjust i, imax.
--i;
--imax;
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