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8324667: fold Parse::seems_stable_comparison()

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Reviewed-by: jkarthikeyan, chagedorn, xliu
This commit is contained in:
Joshua Cao 2024-01-29 19:54:42 +00:00 committed by Xin Liu
parent fb07bbe7b2
commit 84deeb6cd5
2 changed files with 3 additions and 18 deletions
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3
src/hotspot/share/opto/parse.hpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@ -564,7 +564,6 @@ class Parse : public GraphKit {
float branch_prediction(float &cnt, BoolTest::mask btest, int target_bci, Node* test);
bool seems_never_taken(float prob) const;
bool path_is_suitable_for_uncommon_trap(float prob) const;
bool seems_stable_comparison() const;
void do_ifnull(BoolTest::mask btest, Node* c);
void do_if(BoolTest::mask btest, Node* c);

18
src/hotspot/share/opto/parse2.cpp
View File

@ -1354,21 +1354,6 @@ bool Parse::seems_never_taken(float prob) const {
return prob < PROB_MIN;
}
// True if the comparison seems to be the kind that will not change its
// statistics from true to false. See comments in adjust_map_after_if.
// This question is only asked along paths which are already
// classified as untaken (by seems_never_taken), so really,
// if a path is never taken, its controlling comparison is
// already acting in a stable fashion. If the comparison
// seems stable, we will put an expensive uncommon trap
// on the untaken path.
bool Parse::seems_stable_comparison() const {
if (C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if)) {
return false;
}
return true;
}
//-------------------------------repush_if_args--------------------------------
// Push arguments of an "if" bytecode back onto the stack by adjusting _sp.
inline int Parse::repush_if_args() {
@ -1572,7 +1557,8 @@ bool Parse::path_is_suitable_for_uncommon_trap(float prob) const {
if (!UseInterpreter) {
return false;
}
return (seems_never_taken(prob) && seems_stable_comparison());
return seems_never_taken(prob) &&
!C->too_many_traps(method(), bci(), Deoptimization::Reason_unstable_if);
}
void Parse::maybe_add_predicate_after_if(Block* path) {