================ @@ -305,6 +305,17 @@ X86 Support Arm and AArch64 Support ^^^^^^^^^^^^^^^^^^^^^^^ +- ARMv7+ targets now default to allowing unaligned access, except Armv6-M, and + Armv8-M without the Main Extension. Baremetal targets should check that the + new default will work with their system configurations, since it requires + that SCTLR.A is 0, SCTLR.U is 1, and that the memory in question is + configured as "normal" memory. We've made the value judgment that the + performance gains here outweigh breakages, since it is difficult to identify + performance loss from disabling unaligned access, but incorrect enabling + unaligned access will generate an obvious alignment fault on ARMv7+. This is + also the default setting for ARM's downstream compilers. We have not changed + the default behavior for ARMv6, but may revisit that decision in the future. ---------------- ilovepi wrote:
Thanks for the suggested edits. I've mostly kept them, but as you mentioned added a bit about the performance/size benefits. https://github.com/llvm/llvm-project/pull/82400 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
