Integrated: 8290432: C2 compilation fails with assert(node->_last_del == _last) failed: must have deleted the edge just produced
Yi Yang
yyang at openjdk.org
Wed Dec 7 03:11:12 UTC 2022
On Sun, 31 Jul 2022 09:28:59 GMT, Yi Yang <yyang at openjdk.org> wrote:
> Hi, can I have a review for this patch? [JDK-8273585](https://bugs.openjdk.org/browse/JDK-8273585) recognized the form of `Phi->CastII->AddI` as additional parallel induction variables. In the following program:
>
> class Test {
> static int dontInline() {
> return 0;
> }
>
> static long test(int val, boolean b) {
> long ret = 0;
> long dArr[] = new long[100];
> for (int i = 15; 293 > i; ++i) {
> ret = val;
> int j = 1;
> while (++j < 6) {
> int k = (val--);
> for (long l = i; 1 > l; ) {
> if (k != 0) {
> ret += dontInline();
> }
> }
> if (b) {
> break;
> }
> }
> }
> return ret;
> }
>
> public static void main(String[] args) {
> for (int i = 0; i < 1000; i++) {
> test(0, false);
> }
> }
> }
>
> `val` is incorrectly matched with the new parallel IV form:
> 
> And C2 further replaces it with newly added nodes, which finally leads the crash:
> 
>
> I think we can add more constraints to the new form. The form of `Phi->CastXX->AddX` appears when using Preconditions.checkIndex, and it would be recognized as additional IV when 1) Phi != phi2, 2) CastXX is controlled by RangeCheck(to reflect changes in Preconditions checkindex intrinsic)
This pull request has now been integrated.
Changeset: acf96c64
Author: Yi Yang <yyang at openjdk.org>
URL: https://git.openjdk.org/jdk/commit/acf96c64b750b1a7badbb2cd1c7021dad36aae1e
Stats: 111 lines in 2 files changed: 105 ins; 0 del; 6 mod
8290432: C2 compilation fails with assert(node->_last_del == _last) failed: must have deleted the edge just produced
Reviewed-by: kvn, thartmann, chagedorn
-------------
PR: https://git.openjdk.org/jdk/pull/9695
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