When pragma of loop transformations is specified, follow-up metadata for
loops is generated after each transformation. On the LLVM side,
follow-up metadata is expected to be a list of properties, such as the
following:
```
!followup = !{!"llvm.loop.vectorize.followup_all", !mp, !isvectorized}
!mp = !{!"llvm.loop.mustprogress"}
!isvectorized = !{"llvm.loop.isvectorized"}
```
However, on the clang side, the generated metadata contains an MDNode
that has those properties, as shown below:
```
!followup = !{!"llvm.loop.vectorize.followup_all", !loop_id}
!loop_id = distinct !{!loop_id, !mp, !isvectorized}
!mp = !{!"llvm.loop.mustprogress"}
!isvectorized = !{"llvm.loop.isvectorized"}
```
According to the
[LangRef](https://llvm.org/docs/TransformMetadata.html#transformation-metadata-structure),
the LLVM side is correct. Due to this inconsistency, follow-up metadata
was not interpreted correctly, e.g., only one transformation is applied
when multiple pragmas are used.
This patch fixes clang side to emit followup metadata in correct format.
31 KiB
31 KiB