[PATCH] D34409: Use 64bit jump table with large code model on 64bit

Tim Northover via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Jun 20 13:56:16 PDT 2017


t.p.northover added a comment.

> The entirely sensible assumption of the PPC backend is that a single function is no longer than 2GB/4GB.

What's being produced is an offset from the basic blocks (.text) to the Jump table (.rodata). That's not necessarily 32-bits, and I think there are entirely legitimate reasons for putting jump tables in .rodata.

I expect something better could be done for PPC, but this is entirely in line with the existing 32-bit code and correctness comes before performance. I pretty strongly object to characterising the patch as "wrong".


https://reviews.llvm.org/D34409





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