[llvm-commits] [llvm] r51019 - in /llvm/trunk: lib/Target/X86/README-SSE.txt lib/Target/X86/X86InstrInfo.td test/CodeGen/X86/vec_set-H.ll

[Evan Cheng]

On May 13, 2008, at 1:22 AM, Duncan Sands wrote:

> Hi Evan,
>
>> On x86, it's safe to treat i32 load anyext as a normal i32 load.  
>> Ditto for i8 anyext load to i16.
>
> if this was loading the last two bytes in a page, then now it will be
> loading two bytes from the next page, which could trap.  Similarly, if

I'm pretty certain that's not possible on x86.

>
> this was loading 2 bytes out of i/o registers, it may now be reading 4
> bytes out of i/o registers, which could have side effects.

Yep, I forgot to check if it's volatile. I'll fix that.

Thanks,

Evan

>
>
> Ciao,
>
> Duncan.