llvm dev - Mar 2016 - Instruction selection pattern for intrinsic returning llvm_any_ty

Hi,

On my out-of-tree target I have an intrinsic

def int_phx_divm_u16 : Intrinsic<[llvm_any_ty],
                                  [llvm_i16_ty, llvm_i16_ty],
                                  [IntrNoMem]>;

that I want to translate to the following instruction during instruction 
selection:

def divm16_pseudo : MyPseudoInst<
     (outs aNh_0_7:$dst, aNh_0_7:$dst2),
     (ins aNh_0_7:$src1, aNh_0_7:$src2)>;

So I've done a pattern the same way I've done for numerous other 
intrinsics (that returns simple types like i16/i32 etc):

def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
           (divm16_pseudo $src1, $src2)>;

But this doesn't work for me:

anonymous_1373(src1, src2):     (divm16_pseudo:i16:i16:i16 ?:i16:$src1, 
?:i16:$src2)

error: In anonymous_1373: Type inference contradiction found, merging 
'i16' into 'Any'
def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
^

So is there a way I can get around this?


Before ISel the call to my intrisic looks like

   %_tmp3 = call %rec6 @llvm.phx.divm.u16.rec6(i16 %_tmp1, i16 %_tmp2)

and %rec6 is

   %rec6 = type { i16, i16 }

Then at ISel, before selection the call is lowered to

   t6: i16,i16 = llvm.phx.divm.u16 TargetConstant:i16<3778>, t2, t4

which fits nicely to my divm16_pseudo that I want to select.

Is there any way I can select this with a tablegen pattern, and not 
having to do selection "manually" in my target's 
MytargetDAGToDAGISel::Select function?

I'm having a bunch of intrisics looking like this and I'd prefer 
selecting them with patterns rather than doing much more verbose stuff 
in C++.

I've tried to look in in-tree targets for something similar but I've 
failed to find anything.

Thanks,
Mikael

> On Mar 30, 2016, at 09:33, Mikael Holmén via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> Hi,
> 
> On my out-of-tree target I have an intrinsic
> 
> def int_phx_divm_u16 : Intrinsic<[llvm_any_ty],
>                                 [llvm_i16_ty, llvm_i16_ty],
>                                 [IntrNoMem]>;
> 
> that I want to translate to the following instruction during instruction
selection:
> 
> def divm16_pseudo : MyPseudoInst<
>    (outs aNh_0_7:$dst, aNh_0_7:$dst2),
>    (ins aNh_0_7:$src1, aNh_0_7:$src2)>;
> 
> So I've done a pattern the same way I've done for numerous other
intrinsics (that returns simple types like i16/i32 etc):
> 
> def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
>          (divm16_pseudo $src1, $src2)>;
It isn’t able to infer the type of the divm16_pseudo instruction, which would be
necessary depending on whether the result’s register class for divm16_pseudo
includes other types. I would expect you would need to add an explicit i16
around the instruction (e.g. (i16 (divm16_pseudo …)), tlahough the error message
does look like it’s having trouble with the operands. You can try inserting the
explicit i16:$src1 there if that still doesn’t work

> 
> But this doesn't work for me:
> 
> anonymous_1373(src1, src2):     (divm16_pseudo:i16:i16:i16 ?:i16:$src1,
?:i16:$src2)
> 
> error: In anonymous_1373: Type inference contradiction found, merging
'i16' into 'Any'
> def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
> ^
> 
> So is there a way I can get around this?
> 
> 
> Before ISel the call to my intrisic looks like
> 
>  %_tmp3 = call %rec6 @llvm.phx.divm.u16.rec6(i16 %_tmp1, i16 %_tmp2)
> 
> and %rec6 is
> 
>  %rec6 = type { i16, i16 }
> 
> Then at ISel, before selection the call is lowered to
> 
>  t6: i16,i16 = llvm.phx.divm.u16 TargetConstant:i16<3778>, t2, t4
> 
> which fits nicely to my divm16_pseudo that I want to select.
> 
> Is there any way I can select this with a tablegen pattern, and not having
to do selection "manually" in my target's
MytargetDAGToDAGISel::Select function?
> 
> I'm having a bunch of intrisics looking like this and I'd prefer
selecting them with patterns rather than doing much more verbose stuff in C++.
> 
> I've tried to look in in-tree targets for something similar but
I've failed to find anything.
> 
> Thanks,
> Mikael
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

Hi,

On 03/30/2016 11:15 AM, Matt Arsenault wrote:
>
>> On Mar 30, 2016, at 09:33, Mikael Holmén via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
>>
>> Hi,
>>
>> On my out-of-tree target I have an intrinsic
>>
>> def int_phx_divm_u16 : Intrinsic<[llvm_any_ty],
>>                                  [llvm_i16_ty, llvm_i16_ty],
>>                                  [IntrNoMem]>;
>>
>> that I want to translate to the following instruction during
instruction selection:
>>
>> def divm16_pseudo : MyPseudoInst<
>>     (outs aNh_0_7:$dst, aNh_0_7:$dst2),
>>     (ins aNh_0_7:$src1, aNh_0_7:$src2)>;
>>
>> So I've done a pattern the same way I've done for numerous
other intrinsics (that returns simple types like i16/i32 etc):
>>
>> def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
>>           (divm16_pseudo $src1, $src2)>;
>
> It isn’t able to infer the type of the divm16_pseudo instruction, which
would be necessary depending on whether the result’s register class for
divm16_pseudo includes other types. I would expect you would need to add an
explicit i16 around the instruction (e.g. (i16 (divm16_pseudo …)), tlahough the
error message does look like it’s having trouble with the operands. You can try
inserting the explicit i16:$src1 there if that still doesn’t work
Thanks!

Adding i16 on the arguments to my instruction

def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
           (divm16_pseudo i16:$src1, i16:$src2)>;

now gives me

anonymous_1654:         (divm16_pseudo:i16:i16:i16 i16:i16:$src1, 
i16:i16:$src2)

error: In anonymous_1654: Type inference contradiction found, merging 
'i16' into 'Any'
def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
^

So at least it doesn't say "?" on the arguments anymore, but then
I
still get the same error about merging i16 and Any.

Since the divm16_pseudo instruction (and the lowered call to the 
intrinsic) defines two i16 values, what would be the syntax for the

(i16 (divm16_pseudo …)

stuff?

I've tried
(i16, i16 (divm16_pseudo i16:$src1, i16:$src2)
and
((i16, i16) (divm16_pseudo i16:$src1, i16:$src2)
and a few other variants without managing to get it through.

Thanks again,
Mikael

>
>
>>
>> But this doesn't work for me:
>>
>> anonymous_1373(src1, src2):     (divm16_pseudo:i16:i16:i16 ?:i16:$src1,
?:i16:$src2)
>>
>> error: In anonymous_1373: Type inference contradiction found, merging
'i16' into 'Any'
>> def : Pat<(int_phx_divm_u16 i16:$src1, i16:$src2),
>> ^
>>
>> So is there a way I can get around this?
>>
>>
>> Before ISel the call to my intrisic looks like
>>
>>   %_tmp3 = call %rec6 @llvm.phx.divm.u16.rec6(i16 %_tmp1, i16 %_tmp2)
>>
>> and %rec6 is
>>
>>   %rec6 = type { i16, i16 }
>>
>> Then at ISel, before selection the call is lowered to
>>
>>   t6: i16,i16 = llvm.phx.divm.u16 TargetConstant:i16<3778>, t2,
t4
>>
>> which fits nicely to my divm16_pseudo that I want to select.
>>
>> Is there any way I can select this with a tablegen pattern, and not
having to do selection "manually" in my target's
MytargetDAGToDAGISel::Select function?
>>
>> I'm having a bunch of intrisics looking like this and I'd
prefer selecting them with patterns rather than doing much more verbose stuff in
C++.
>>
>> I've tried to look in in-tree targets for something similar but
I've failed to find anything.
>>
>> Thanks,
>> Mikael
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>
>