[LLVMdev] changing -mattr behavior with mmx and sse
Stefanus Du Toit
stefanus.dutoit at rapidmind.com
Thu Nov 20 14:46:10 PST 2008
For what it's worth, we've been operating in this mode for a while now
(using a somewhat brute force local patch), and haven't seen any
issues with it so far.
On 20-Nov-08, at 1:09 PM, Mon Ping Wang wrote:
> Hi Dale,
> I will not change the default. I would dislike to see any regressions
> due to this type of change.
> -- Mon Ping
> On Nov 20, 2008, at 10:12 AM, Dale Johannesen wrote:
>> On Nov 19, 2008, at 11:57 PMPST, Mon Ping Wang wrote:
>>> When setting -mattr option on X86, I would like to treat MMX
>>> separately from SSE levels. This would allow a client who sets the
>>> attributes directly to set the SSE level independent of MMX, e.g.,
>>> -march=x86 -mattr=sse41, one would get sse4.1 with mmx disabled
>>> llc -march=x86 -mattr=mmx -mattr=sse42 will get mmx and sse42. If
>>> anyone objects to this change, please let me know.
>> I don't object, but please don't change the defaults.
>> You're likely to find places the SSE code assumes MMX exists...
>> LLVM Developers mailing list
>> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu
Stefanus Du Toit <stefanus.dutoit at rapidmind.com>
phone: +1 519 885 5455 x116 -- fax: +1 519 885 1463
More information about the llvm-dev