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8204157: Compiler.sunflow hangs after JDK-8192992

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Treat non-loop phis as stores

Reviewed-by: thartmann
This commit is contained in:
Nils Eliasson 2018-06-27 18:46:30 +02:00
parent 4029057547
commit 8e9f9e5583
1 changed files with 32 additions and 31 deletions

63
src/hotspot/share/opto/gcm.cpp

@ -683,38 +683,40 @@ Block* PhaseCFG::insert_anti_dependences(Block* LCA, Node* load, bool verify) {
Block* store_block = get_block_for_node(store);
assert(store_block != NULL, "unused killing projections skipped above");
if (store->is_Phi()) {
if (store->in(0)->is_Loop()) {
// 'load' uses memory which is one (or more) of the Phi's inputs.
// It must be scheduled not before the Phi, but rather before
// each of the relevant Phi inputs.
//
// Instead of finding the LCA of all inputs to a Phi that match 'mem',
// we mark each corresponding predecessor block and do a combined
// hoisting operation later (raise_LCA_above_marks).
//
// Do not assert(store_block != early, "Phi merging memory after access")
// PhiNode may be at start of block 'early' with backedge to 'early'
DEBUG_ONLY(bool found_match = false);
for (uint j = PhiNode::Input, jmax = store->req(); j < jmax; j++) {
if (store->in(j) == mem) { // Found matching input?
DEBUG_ONLY(found_match = true);
Block* pred_block = get_block_for_node(store_block->pred(j));
if (pred_block != early) {
// If any predecessor of the Phi matches the load's "early block",
// we do not need a precedence edge between the Phi and 'load'
// since the load will be forced into a block preceding the Phi.
pred_block->set_raise_LCA_mark(load_index);
assert(!LCA_orig->dominates(pred_block) ||
early->dominates(pred_block), "early is high enough");
must_raise_LCA = true;
} else {
// anti-dependent upon PHI pinned below 'early', no edge needed
LCA = early; // but can not schedule below 'early'
}
if (store->is_Phi() && store->in(0)->is_Loop()) {
// Loop-phis need to raise load before input. (Other phis are treated
// as store below.)
//
// 'load' uses memory which is one (or more) of the Phi's inputs.
// It must be scheduled not before the Phi, but rather before
// each of the relevant Phi inputs.
//
// Instead of finding the LCA of all inputs to a Phi that match 'mem',
// we mark each corresponding predecessor block and do a combined
// hoisting operation later (raise_LCA_above_marks).
//
// Do not assert(store_block != early, "Phi merging memory after access")
// PhiNode may be at start of block 'early' with backedge to 'early'
DEBUG_ONLY(bool found_match = false);
for (uint j = PhiNode::Input, jmax = store->req(); j < jmax; j++) {
if (store->in(j) == mem) { // Found matching input?
DEBUG_ONLY(found_match = true);
Block* pred_block = get_block_for_node(store_block->pred(j));
if (pred_block != early) {
// If any predecessor of the Phi matches the load's "early block",
// we do not need a precedence edge between the Phi and 'load'
// since the load will be forced into a block preceding the Phi.
pred_block->set_raise_LCA_mark(load_index);
assert(!LCA_orig->dominates(pred_block) ||
early->dominates(pred_block), "early is high enough");
must_raise_LCA = true;
} else {
// anti-dependent upon PHI pinned below 'early', no edge needed
LCA = early; // but can not schedule below 'early'
}
}
assert(found_match, "no worklist bug");
}
assert(found_match, "no worklist bug");
#ifdef TRACK_PHI_INPUTS
#ifdef ASSERT
// This assert asks about correct handling of PhiNodes, which may not
@ -728,7 +730,6 @@ Block* PhaseCFG::insert_anti_dependences(Block* LCA, Node* load, bool verify) {
"Expect at least one phi input will not be from original memory state");
#endif //ASSERT
#endif //TRACK_PHI_INPUTS
}
} else if (store_block != early) {
// 'store' is between the current LCA and earliest possible block.
// Label its block, and decide later on how to raise the LCA