[PATCH] Add HLE target feature

[Jeffrey Yasskin]

> On Wed, 2013-02-20 at 16:51 -0800, Jeffrey Yasskin wrote:
>> Don't take me as authoritative, but it seems sensible to add clang and
>> LLVM support for these instructions if there's enough of a spec for
>> the language-level operations to describe when the compiler can
>> optimize around them. For example, the C11 atomics allow the compiler
>> to reorder non-atomic operations across atomic operations in certain
>> circumstances.
>>
>> Is there a description of the language-level semantics of the
>> operations you're adding, or does it all rely on the instruction set
>> definition? Could a compiler decide that it's a good idea to add these
>> prefixes on its own?

On Wed, Feb 20, 2013 at 4:59 PM, Michael Liao <michael.liao at intel.com> wrote:
> These patches are developed to follow GCC's approach supporting HLE.

The patch you pointed to in GCC didn't add documentation there either.
I'm nervous about undocumented features.