f486cc4417
Flang currently adds loop metadata to a conditional branch in the loop preheader, while clang adds it to the loop latch's branch instruction. Langref says: > Currently, loop metadata is implemented as metadata attached to the branch instruction in the loop latch block. > > https://llvm.org/docs/LangRef.html#llvm-loop I misread langref a couple times, but I think this is the appropriate branch op for the LoopAnnotationAttr. In a couple examples I found that the metadata was lost entirely during canonicalization. This patch makes the codegen look more like clang's and the annotations persist through codegen. * current clang: https://godbolt.org/z/8WhbcrnG3 * current flang: https://godbolt.org/z/TrPboqqcn