[LLVMdev] [BUG] Support unqualified btr, bts

Eli Friedman eli.friedman at gmail.com
Wed Jul 10 11:30:03 PDT 2013

On Wed, Jul 10, 2013 at 11:12 AM, Ramkumar Ramachandra
<artagnon at gmail.com> wrote:
> Hi,
> I happened to notice that linux.git uses plenty of btr and bts
> instructions (not btrl, btrw, btsl, btsw).  For examples, see
> arch/x86/include/asm/bitops.h.  LLVM barfs on these due to ambiguity,
> while GNU as is fine with them.  Surely, there must be architectures
> where the w/l variant is unavailable?

Both variants have existed since the Intel 386.

That said, we should probably handle this like GNU as because the
variants behave almost identically.  Please file a bug.


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