Summary:
The option `-mpad-max-prefix-size` performs some checking and delegate to MC option `-x86-pad-max-prefix-size`. This option is designed for eliminate NOPs when we need to align something by adding redundant prefixes to instructions, e.g. it can be used along with `-malign-branch`, `-malign-branch-boundary` to prefix padding branch.
It has similar (but slightly different) effect as GAS's option `-malign-branch-prefix-size`, e.g. `-mpad-max-prefix-size` can also elminate NOPs emitted by align directive, so we use a different name here. I remove the option `-malign-branch-prefix-size` since is unimplemented and not needed. If we need to be compatible with GAS, we can make `-malign-branch-prefix-size` an alias for this option later.
Reviewers: jyknight, reames, MaskRay, craig.topper, LuoYuanke
Reviewed By: MaskRay, LuoYuanke
Subscribers: annita.zhang, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D77628
These driver options perform some checking and delegate to MC options -x86-align-branch* and -x86-branches-within-32B-boundaries.
Reviewed By: skan
Differential Revision: https://reviews.llvm.org/D72463
Shengchen Kan