[llvm][CodeGen] Fix failure in window scheduler caused by phi #95900
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In certain cases, the register passed with the kernel MBB in phi are not defined within the kernel MBB. The window algorithm currently does not support such scenarios, so a check is performed during initialization.
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The cause of the issue is that in the phi instruction, the register passed along with the kernel MBB is not defined within the kernel MBB. We have added some handling codes. |
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Could you please review this code? Thank you~ @nathanchance @arsenm @dtcxzyw |
arsenm
reviewed
Jun 18, 2024
llvm/lib/CodeGen/WindowScheduler.cpp
Outdated
| if (Register AntiReg = getAntiRegister(&MI)) | ||
| // Register with Kernel in phi is not defined within the Kernel itself. | ||
| if (MRI->getVRegDef(AntiReg)->getParent() != MBB) { | ||
| LLVM_DEBUG(dbgs() << "Special phi structure is not supported!\n"); |
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It's not really special. Why is this difficult to handle? It should behave like any other live in value
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Yes, you are right. We only need to add some checks.
Updated.
arsenm
approved these changes
Jun 18, 2024
AlexisPerry
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Jul 9, 2024
…5900) In certain cases, the register passed with the kernel MBB in phi are not defined within the kernel MBB. This patch adds the corresponding handling.
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In certain cases, the register passed with the kernel MBB in phi are not defined
within the kernel MBB. This patch adds the corresponding handling.