[PATCH] D107522: [PowerPC][AIX] attribute aligned cannot decrease align of a vector var.

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman added inline comments.


================
Comment at: clang/lib/Sema/SemaDeclAttr.cpp:4064-4068
   if (Context.getTargetInfo().isTLSSupported()) {
     unsigned MaxTLSAlign =
         Context.toCharUnitsFromBits(Context.getTargetInfo().getMaxTLSAlign())
             .getQuantity();
     if (MaxTLSAlign && AlignVal > MaxTLSAlign && VD &&
----------------



================
Comment at: clang/lib/Sema/SemaDeclAttr.cpp:4076
 
+  // On AIX, an aligned attribute can not decrease the alignemnt when applied
+  // to a variable declaration with vector type.
----------------



================
Comment at: clang/lib/Sema/SemaDeclAttr.cpp:4081
+    if (Ty->isVectorType() && AlignVal < 16)
+      return;
+  }
----------------
This should produce a diagnostic rather than silently drop the attribute. I'd recommend `err_alignas_underaligned` if you're willing to make this an error. If not, you could add a new warning with the same wording.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107522/new/

https://reviews.llvm.org/D107522