This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [Patch: i386] Prohibit invalide ISA combination
On Fri, Dec 5, 2008 at 12:47 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Dec 5, 2008 at 12:43 PM, Andrew Pinski <pinskia@gmail.com> wrote:
>> On Fri, Dec 5, 2008 at 7:36 AM, Ye, Joey <joey.ye@intel.com> wrote:
>>> This patch solves http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38201
>>
>> Why do we want to do this restriction again? It is one thing if the
>> instructions overlap but we should allow users to decide if they want
>> to have these instruction sets turned on.
>>
>> Thanks,
>> Andrew Pinski
>>
>
> What should gcc generate with -mfma -msse5 for
You are not answering my question. You are asking a different
question. So -mfma and -msse5 both have a Fused Multiple and Add
instruction. It could generate either version of the instruction. So
a simulator or even some processor in the future could implement both
sets of fmas and then we have to change GCC again to support this
which I think is incorrect.
Thanks,
Andrew Pinski