[AMDGPU] Handle empty-except-for-DI regions in PreRARematerialize#524
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ronlieb merged 1 commit intoamd-mainlinefrom Nov 9, 2025
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The existing check for this case only comes after a derefence of what can be an iterator sentinel (leading to an assert). This may not be purely NFC in that it also avoids queuing the effectively-empty region for rescheduling, but AFAICT this should be purely an optimization. Testing this seems difficult, as the high-level scheduler avoids scheduling these "empty" regions. This means a reproducer has to depend on behavior of the scheduler passes before PreRARematStage in order to craft a region which triggers the bug. Since this is a release blocker I am posting a PR now, as both Shore Shen and I have manually verified that this resolves the particular crash from SWDEV-564142 but I am still working on making a reasonable test. (cherry picked from commit 004cfea)
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bcahoon
approved these changes
Nov 7, 2025
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Testcase? |
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Why is this direct to mainline? |
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!PSDB |
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Originally merged into amd-staging @ #516 and I intend to go upstream, but as you note I don't have a reasonable testcase yet. The issue with building a test is that this affects a phase of the scheduler in a way that depends on the details of earlier phases. There is also a lot of IR to churn through trying to get to a reproducer, and naively running I'm still working on it, though |
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The existing check for this case only comes after a derefence of what can be an iterator sentinel (leading to an assert).
This may not be purely NFC in that it also avoids queuing the effectively-empty region for rescheduling, but AFAICT this should be purely an optimization.
Testing this seems difficult, as the high-level scheduler avoids scheduling these "empty" regions. This means a reproducer has to depend on behavior of the scheduler passes before PreRARematStage in order to craft a region which triggers the bug.
Since this is a release blocker I am posting a PR now, as both Shore Shen and I have manually verified that this resolves the particular crash from SWDEV-564142 but I am still working on making a reasonable test.
(cherry picked from commit 004cfea)