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The PowerPC back-end uses BLA to implement calls to functions at known-constant addresses, which is apparently used for certain system routines on Darwin. However, with the 64-bit SVR4 ABI, this is actually incorrect. An immediate function pointer value on this platform is not directly usable as a target address for BLA: - in the ELFv1 ABI, the function pointer value refers to the *function descriptor*, not the code address - in the ELFv2 ABI, the function pointer value refers to the global entry point, but BL(A) would only be correct when calling the *local* entry point This bug didn't show up since using immediate function pointer values is not usually done in the 64-bit SVR4 ABI in the first place. However, I ran into this issue with a certain use case of LLVM as JIT, where immediate function pointer values were uses to implement callbacks from JITted code to helpers in statically compiled code. Fixed by simply not using BLA with the 64-bit SVR4 ABI. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211174 91177308-0d34-0410-b5e6-96231b3b80d8
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