Integrated: 8253756: C2 CompilerThread0 crash in Node::add_req(Node*)

[Roland Westrelin]

On Wed, 7 Oct 2020 07:48:23 GMT, Roland Westrelin <roland at openjdk.org> wrote:

> The outer strip mined loop is initially created as a skeleton and then
> expanded once loop opts are over. As long as it is a skeleton, the
> OuterStripMinedLoopEndNode cannot be constant folded because its input
> is a place holder. So OuterStripMinedLoopEndNode::Value() blocks
> constant folding. This bug triggers because the
> OuterStripMinedLoopEndNode input after expansion is a constant but the
> OuterStripMinedLoopEndNode is not constant folded (i.e. it's a dead
> loop but it stays in the graph). The fix I propose is to change the
> behavior OuterStripMinedLoopEndNode::Value() so it blocks constant
> folding only until expansion but not after.

This pull request has now been integrated.

Changeset: 76a58527
Author:    Roland Westrelin <roland at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/76a58527
Stats:     83 lines in 3 files changed: 82 ins; 0 del; 1 mod

8253756: C2 CompilerThread0 crash in Node::add_req(Node*)

Reviewed-by: vlivanov, thartmann

-------------

PR: https://git.openjdk.java.net/jdk/pull/537