[PATCH] D155894: [BPF] allow external calls

[Alexei Starovoitov via Phabricator via llvm-commits]

ast added inline comments.


================
Comment at: llvm/lib/Target/BPF/BPFISelLowering.cpp:466
     Callee = DAG.getTargetExternalSymbol(E->getSymbol(), PtrVT, 0);
-    fail(CLI.DL, DAG, Twine("A call to built-in function '"
-                            + StringRef(E->getSymbol())
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How does it help aya?

In general I think it's ok to remove this, but we need to define the behavior more accurately here.
Does it mean that we promote builtin to global ? What is the visibility of such symbol? What relocation do we use ? What libbpf and libbpf linker should do with it?

In particular with memcpy, do we generate asm that calls "llvm.memcpy.p0.p0.i64" name or does it become plain "memcpy" ?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D155894/new/

https://reviews.llvm.org/D155894