[PATCH] D122377: [PowerPC][Linux] Support 16-byte lock free atomics on pwr8 and up

[Hubert Tong via Phabricator via cfe-commits]

hubert.reinterpretcast added inline comments.


================
Comment at: clang/test/CodeGen/PowerPC/atomic-alignment.c:34
 
 // PPC32: @o = global %struct.O zeroinitializer, align 1{{$}}
 // PPC64: @o = global %struct.O zeroinitializer, align 8{{$}}
----------------
Just noting that GCC increases the alignment even for ppc32:
```
typedef struct A8 { char x[8]; } A8;
typedef struct A16 { char x[16]; } A16;
extern char q8[_Alignof(_Atomic(A8))], q8[8]; // okay for GCC targeting ppc32
extern char q16[_Alignof(_Atomic(A16))], q16[16]; // okay for GCC targeting ppc32
```

Apparently, the change for i686 in GCC occurred with version 11.
https://godbolt.org/z/fTTGoqWW1


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122377/new/

https://reviews.llvm.org/D122377