Re: [PATCH v2 6/6] i386: Implement asm flag outputs

[Jeff Law <law at redhat dot com>]

On 05/15/2015 09:37 AM, Richard Henderson wrote:
> Version 2 includes proper test cases and documentation.
> Hopefully the documentation even makes sense.  Suggestions
> and improvements there gratefully appreciated.
>
>
> r~
> ---
>   gcc/config/i386/constraints.md             |   5 ++
>   gcc/config/i386/i386.c                     | 137 +++++++++++++++++++++++++++--
>   gcc/doc/extend.texi                        |  76 ++++++++++++++++
>   gcc/testsuite/gcc.target/i386/asm-flag-0.c |  15 ++++
>   gcc/testsuite/gcc.target/i386/asm-flag-1.c |  18 ++++
>   gcc/testsuite/gcc.target/i386/asm-flag-2.c |  16 ++++
>   gcc/testsuite/gcc.target/i386/asm-flag-3.c |  22 +++++
>   gcc/testsuite/gcc.target/i386/asm-flag-4.c |  20 +++++
>   gcc/testsuite/gcc.target/i386/asm-flag-5.c |  19 ++++
>   9 files changed, 321 insertions(+), 7 deletions(-)
>   create mode 100644 gcc/testsuite/gcc.target/i386/asm-flag-0.c
>   create mode 100644 gcc/testsuite/gcc.target/i386/asm-flag-1.c
>   create mode 100644 gcc/testsuite/gcc.target/i386/asm-flag-2.c
>   create mode 100644 gcc/testsuite/gcc.target/i386/asm-flag-3.c
>   create mode 100644 gcc/testsuite/gcc.target/i386/asm-flag-4.c
>   create mode 100644 gcc/testsuite/gcc.target/i386/asm-flag-5.c
It all seems to make sense.  Obviously you'll need a ChangeLog and the 
usual testing before committing.

I won't stress much if this needs a bit of further tweaking as the 
kernel folks start to exploit the capability and we find weaknesses in 
the implementation.

What I don't see is any way to know if the target supports asm flag 
outputs.  Are we expecting the kernel folks to do some kind of test then 
enable/disable based on the result?

I'm going to assume the mapping of the constraints to the actual modes 
and codes is correct.


Jeff