[LLVMdev] [PATCH] x86: disambiguate unqualified btr, bts

[Ramkumar Ramachandra]

Jim Grosbach wrote:
> To say that another way, is the assembler correctly diagnosing a previously
> unnoticed problem in the project source code, or is the assembler not
> behaving correctly according the the documented Intel assembly mnemonics?

Where are the authoritative instruction set pages?  If such a thing
were readily available, why are there gaps in the current
implementation?  A quick Googling gets me [1], but I can't say it's
authoritative.  What's important is that there certainly are
architectures where btr/bts are valid instructions, and they must be
supported.  btr/bts are certainly not invalid instructions that we're
bending over backwards to support, because linux.git/gas works with
them.

[1]: http://web.itu.edu.tr/kesgin/mul06/intel/index.html