When generating code with sanitize_memtag, we make use of the fact that the sp+imm forms of many load and store instructions are not tag-checked, so we can use SP directly instead of needing a register holding the tagged pointer. However, this isn't true for the writeback versions of the instructions, so we can't fold ADDs and SUBs into them in AArch64LoadStoreOptimizer. This would be possible in cases where the loads/stores only access untagged stack slots, but that information isn't easily available after frame index elimination.
107 KiB
107 KiB