This patch enables fine-grained tuning control for ldp and stp.
It provides two new and concrete command-line options -aarch64-ldp-policy
and -aarch64-stp-policy to give the ability to control load and store
policies seperately with both clang and flang-new frontends including
when using -flto.
The accepted values for both options are:
- default: Use the ldp/stp policy currently used by the compiler (always).
- always: Emit ldp/stp regardless of alignment.
- never: Do not emit ldp/stp.
- aligned: In order to emit ldp/stp, first check if the load/store will be aligned to 2 * element_size.