@ t.p.northover Could you take a look again when you're available? Thanks!

• Fix clang-tidy from pre-merge check

• Rebase it to the latest
• Expand the epilog corner case where x16 lives across blocks
• Fix a comment

• Fix pre-merge checks by using variable_ops in pseudo.

• Fix clang-tidy/format issues

Update for @t.p.northover feedbacks

Reabse

I would appreciate if anyone can review this.

@efriedma Could you have a chance to take a look this again?

Rebase

This rewrites the helper functions:

• One SP Adjustment to reduce micro-opts for the better perf.
• Align Linux/Darwin implementation in the same way . X29/X30 is stored at the call-site and that stack space is skipped in the prolog helper.
• Add some comments and expand the enabling check.

@efriedma Unlike other work that uses a helper call to runtime library, this work synthesizes outlined functions with a custom-calling convention. This is handy and flexible to extend this logic for other patterns or purposes like instrumentation, etc inside the helper within the compiler.

I think it looks good to me. @MaskRay Any further feedback on this?

Rebase and add more tests.

Rebase.

@plotfi Can you commit this for me? Thanks in advance!

• Preserve the original flag -force-attribute
• Factor out hasForceAttributes into D85793

Fix typos from the feedback.

Kindly ping.. This patch is convenient to chase down an issue by adding as well as removing an attribute of the function.

Fix case style for ParseFunctionAndAttr

Fix for Outlined Epilog for a Tail-Call

@plotfi I hit this in an internal workload (-Oz -flto=thin), but it won't surprise if the same issue is in llvm-test-suite.

rebase

Rebase after D83456

Fix for merge

Refactor getArgumentPopSize() to D83456
Add comment on producePairRegisters()

Updating for Linux support.