Well, these kinds of asm are inherently target specific, but I did already ask for a cpp symbol to indicate this faculty us available.
On May 20, 2015 9:21:07 AM PDT, Jeff Law <l...@redhat.com> wrote: >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 -- Sent from my mobile phone. Please pardon brevity and lack of formatting.