1. Revert "Add default feature for CPUs on AArch64 target in Clang"
at r210625. Then, all enabled feature will by passed explicitly by
-target-feature in -cc1 option.
2. Get "-mfpu" deprecated.
3. Implement support of "-march". Usage is:
-march=armv8-a+[no]feature
For instance, "-march=armv8-a+neon+crc+nocrypto". Here "armv8-a" is
necessary, and CPU names are not acceptable. Candidate features are
fp, neon, crc and crypto. Where conflicting feature modifiers are
specified, the right-most feature is used.
4. Implement support of "-mtune". Usage is:
-march=CPU_NAME
For instance, "-march=cortex-a57". This option will ONLY get
micro-architectural feature enabled specifying to target CPU,
like "+zcm" and "+zcz" for cyclone. Any architectural features
WON'T be modified.
5. Change usage of "-mcpu" to "-mcpu=CPU_NAME+[no]feature", which is
an alias to "-march={feature of CPU_NAME}+[no]feature" and
"-mtune=CPU_NAME" together. Where this option is used in conjunction
with -march or -mtune, those options take precedence over the
appropriate part of this option.
llvm-svn: 213353
110db6f2ad