Use Clang's logic for adding the default IR attributes to a function

[rjmccall]

A lot of attributes are essentially default target configuration, and we should only differ when there's a good reason to.

For the attributes we were already setting:

• the ptrauth and target CPU/feature attributes are taken care of by Clang
• I've updated the optsize/minsize attributes to the apparent intent
• I've left the frame-pointer override in place for now

Fixes rdar://63289339, which was caused by Swift's ptrauth IR attributes getting out of sync with Clang's.

[rjmccall]

swiftlang/llvm-project#1245

@swift-ci Please test.

[rjmccall]

@stephentyrone This is also setting the LLVM floating-point attributes to match Clang's by default, so that e.g. on Darwin x86-64 I see for a simple Swift function:

attributes #0 = {
  norecurse
  nounwind
  readnone
  "correctly-rounded-divide-sqrt-fp-math"="false"
  "frame-pointer"="all"
  "less-precise-fpmad"="false"
  "no-infs-fp-math"="false"
  "no-nans-fp-math"="false"
  "no-signed-zeros-fp-math"="false"
  "no-trapping-math"="false"
  "stack-protector-buffer-size"="8"
  "target-cpu"="penryn"
  "target-features"="+cx16,+cx8,+fxsr,+mmx,+sahf,+sse,+sse2,+sse3,+sse4.1,+ssse3,+x87"
  "unsafe-fp-math"="false
  "use-soft-float"="false"
}

I don't know if anything in here strikes you as problematic.

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 0bc8ec28b5df102a7846176dc865559c94820a29

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 0bc8ec28b5df102a7846176dc865559c94820a29

[jckarter]

Makes sense to me. Thanks John!

[rjmccall]

swiftlang/llvm-project#1245

@swift-ci Please test

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 0bc8ec28b5df102a7846176dc865559c94820a29

[rjmccall]

@compnerd Is there something special about the Windows builder that would make it not respect cross-repository testing?

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 0bc8ec28b5df102a7846176dc865559c94820a29

[compnerd]

Yeah, the cross-repository settings are not propagated to the checkout on Windows. @shahmishal was going to look into that (at least had expressed that he was interested in doing so a while ago).

[shahmishal]

Yeah, the cross-repository settings are not propagated to the checkout on Windows. @shahmishal was going to look into that (at least had expressed that he was interested in doing so a while ago).

Yes, I don't if I will be able to for few weeks.

[rjmccall]

swiftlang/llvm-project#1247

@swift-ci Please test.

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 0bc8ec28b5df102a7846176dc865559c94820a29

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 0bc8ec28b5df102a7846176dc865559c94820a29

[rjmccall]

swiftlang/llvm-project#1247

@swift-ci Please test.

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - 2f8ec9d2c712671394e4e91435288be918caea9d

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 2f8ec9d2c712671394e4e91435288be918caea9d

[stephentyrone]

I don't know if anything in here strikes you as problematic.

Those all seem appropriate to me.