[llvm-commits] [llvm] r107996 - in /llvm/trunk: lib/Target/X86/AsmPrinter/X86ATTInstPrinter.h lib/Target/X86/AsmPrinter/X86IntelInstPrinter.h lib/Target/X86/X86InstrInfo.cpp lib/Target/X86/X86InstrInfo.td lib/Target/X86/X86InstrSSE.td lib/Target/

[Bruno Cardoso Lopes]

On Fri, Jul 9, 2010 at 2:40 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote:
>
> On Jul 9, 2010, at 11:27 AM, Bruno Cardoso Lopes wrote:
>
>>
>>   // YMM Registers, used by AVX instructions
>> -  let SubRegIndices = [sub_xmm] in {
>> +  // The sub_ss and sub_sd subregs are the same registers with another regclass.
>> +  let CompositeIndices = [(sub_ss), (sub_sd)], SubRegIndices = [sub_xmm] in {
>>   def YMM0: RegisterWithSubRegs<"ymm0", [XMM0]>, DwarfRegNum<[17, 21, 21]>;
>>   def YMM1: RegisterWithSubRegs<"ymm1", [XMM1]>, DwarfRegNum<[18, 22, 22]>;
>>   def YMM2: RegisterWithSubRegs<"ymm2", [XMM2]>, DwarfRegNum<[19, 23, 23]>;
>
> Was this change on purpose?
>
> It means that getSubReg(YMM0, sub_ss) returns YMM0 instead of XMM0. Do you want to do scalar operations in YMM registers?
>
> If you just want getSubReg(YMM0, sub_ss) -> XMM0, just leave it as it was before. YMM0 will inherit the sub_ss subregister from XMM0.
>
> Look at X86GenRegisterInfo::getSubReg:
>
>  case X86::YMM0:
>    switch (Index) {
>    default: return 0;
>    case X86::sub_sd: return X86::YMM0;
>    case X86::sub_ss: return X86::YMM0;
>    case X86::sub_xmm: return X86::XMM0;
>    };
>    break;

My bad indeed. I'll fix it! :)



-- 
Bruno Cardoso Lopes
http://www.brunocardoso.cc