[PATCH] D91611: [PowerPC][LLD] Detecting and fixing missing TLS relocation on __tls_get_addr

[Sean Fertile via Phabricator via llvm-commits]

sfertile added inline comments.


================
Comment at: lld/ELF/Relocations.cpp:1316
+    const RelType prevType = prevRel.getType(config->isMips64EL);
+    // Check if this call to __tls_get_addr is part of a TLS sequence.
+    if (prevType == R_PPC64_GOT_TLSGD16_HA ||
----------------
I don't think this is something you can reliably determine. For example consider the code:

```
       # r30 is previously saved to the stack.
       # setup r3 for the call to __tls_get_addr
        addis 3, 2, i at got@tlsgd at ha
        addi 3, 3, i at got@tlsgd at l
       # Load unrelated variable into a non-volatile register so it will stay live across the call.
        addis 30, 2, j at toc@ha
        addi 30, j at toc@l(30)
        # call __tls_get_addr. Relocation I - 2 is NOT one of the relocations used to setup the argument.
        bl __tls_get_addr(i at tlsgd)
        nop
```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D91611/new/

https://reviews.llvm.org/D91611