[PATCH] D98305: [JITLink] Introduce generic x86-64 support by refactoring MachO/x86-64.

Thu Mar 11 09:06:01 PST 2021

sgraenitz added a comment.

Factoring out architecture specific code sounds like a reasonable approach to reduce code duplication across the JITLink backends. As far as I can see, the patch only ports the MachOJITLinker_x86_64 to use the generic functionality. The ELFJITLinker_x86_64 mostly remains unchanged. Is there a conceptual reason for it or would that be a rather straightforward next step?

What I am not sure I understand yet is how endianness is handled in this scheme. The new applyFixup() function is using hard casts to little-endian when writing fixup values into memory. Is that because addRelocations() is supposed to populate the fixup values with the correct endian already? I think the ELF implementation didn't consider it at all so far, so there is no loss of functionality. Just asking for interest.

Great documentation for the edge kinds!

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Comment at: llvm/include/llvm/ExecutionEngine/JITLink/x86_64.h:206
+  ///
+  /// If the TLVP entry target is in-range of the fixup then the load frmo the
+  /// TLVP may be replaced with a direct memory address calculation.
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Typo: from

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  https://reviews.llvm.org/D98305/new/

https://reviews.llvm.org/D98305