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Summary: We were already using 32-bit jump table entries, but this was a consequence of the default PIC model on Win64, and not an intentional design decision. This patch ensures that we always use 32-bit label difference jump table entries on Win64 regardless of the PIC model. This is a good idea because it saves executable size and object file size. Moving the jump tables to .rdata cleans up the disassembled object code and reduces the available ROP targets, but it requires adding one more RIP-relative lea to the code. COFF doesn't have relocations to express the difference between two arbitrary symbols, so we can't use the jump table label in the label difference like we do elsewhere. Fixes PR31488 Reviewers: majnemer, compnerd Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D28141 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290694 91177308-0d34-0410-b5e6-96231b3b80d8
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