On Thu, Dec 18, 2014 at 9:23 AM, Uros Bizjak <ubiz...@gmail.com> wrote: > On Thu, Dec 18, 2014 at 6:08 PM, H. Peter Anvin <h...@zytor.com> wrote: >> On 12/18/2014 06:12 AM, Uros Bizjak wrote: >>>>> >>>>> # temporary until string.h is fixed >>>>> KBUILD_CFLAGS += -ffreestanding >>>>> >>>>> Yes, it looks to me that new option is the way to go. >>>> >>>> Is this an OK? >>> >>> In principle, I'm OK with the patch approach, but let's wait for >>> eventual comments from Linux people. >>> >> >> Acked-by: H. Peter Anvin <h...@linux.intel.com> >> >> H.J. already coordinated with us; we are more than happy with this approach. > > Great, I'm glad that this specialized option has uses. > > Patch is OK.
It is in now. Here is the GCC 5 change entry. OK to install? Peter, please feel free to use my kernel patch or create a different one. Thanks. -- H.J. --- Index: gcc-5/changes.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-5/changes.html,v retrieving revision 1.52 diff -u -p -r1.52 changes.html --- gcc-5/changes.html 15 Dec 2014 19:55:08 -0000 1.52 +++ gcc-5/changes.html 18 Dec 2014 17:42:18 -0000 @@ -444,6 +444,10 @@ void operator delete[] (void *, std::siz place of the __fentry__ or mcount call, so that a call per function can be later patched in. This can be used for low overhead tracing or hot code patching.</li> + <li>The new <code>-mskip-rax-setup</code> option to skip setting + up RAX register when SSE is disabled and there are no variable + arguments passed in vector registers. This can be used to + optimize Linux kernel.</li> </ul> <h3 id="sh">SH</h3>
