llvm dev - Jan 2020 - unified register set question

My target machine uses the same 64-bit registers for integers and floating 
point.  Do I have to specify a different register class for floating point
that uses the same set of registers?  Is there a target which does this I can
copy?

thanks,
brian

> On Jan 9, 2020, at 15:28, Bagel via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> My target machine uses the same 64-bit registers for integers and floating
point.  Do I have to specify a different register class for floating point
> that uses the same set of registers?  Is there a target which does this I
can copy?
No, you can add any combination of types to the register class. AMDGPU doesn’t
distinguish between FP and int registers.

-Matt

On 1/9/20 2:41 PM, Matt Arsenault wrote:
> 
> 
>> On Jan 9, 2020, at 15:28, Bagel via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
>>
>> My target machine uses the same 64-bit registers for integers and
floating point.  Do I have to specify a different register class for floating
point
>> that uses the same set of registers?  Is there a target which does this
I can copy?
> 
> No, you can add any combination of types to the register class. AMDGPU
doesn’t distinguish between FP and int registers.
> 
That's good to know.  However, the register definitions for AMDGPU are over 
1000 lines.  I had hoped to learn from something simpler :-)

My current attempt generates a lot of error messages of the type:
"Could not infer all types in pattern result!", e.g.:

/home/bgl/src/llvm-local/llvm/lib/Target/My66000/My66000InstrInfo.td:360:3: 
error: In STDri: Could not infer all types in pattern result!
   def ri : LDST_BD<OpCri,
   ^
Included from /home/bgl/src/llvm-local/llvm/lib/Target/My66000/My66000.td:24:
/home/bgl/src/llvm-local/llvm/lib/Target/My66000/My66000InstrInfo.td:370:14: 
note: instantiated from multiclass
   defm STD : Store<"std", 0b101011, 0b001011, store>;
              ^
STDrr: 	(st GRegs:{ *:[i64 f64] }:$rd, ADDRrr:{ *:[iPTR] 
}:$addr)<<P:Predicate_unindexedstore>><<P:Predicate_store>>