llvm dev - Jul 2016 - Missing TargetPrefix for NVVM intrinsics

Justins:

I noticed that the intrinsics in IntrinsicsNVVM don't specify a
TargetPrefix. This seems like a simple omission, so I was going to
simply throw a `let TargetPrefix = "nvvm" ` block around them, but
this
doesn't quite work.

There seem to be three prefixes that are used in this file. About 900
are int_nvvm_*, 30 are int_ptx_*, and 1 is int_cuda. It isn't clear to
me if this inconsistency is intentional or warranted - should these all
be named int_nvvm_*? Is there a good reason to differentiate int_ptx_*?
Why does __syncthreads map to int_cuda_syncthreads, rather than
int_nvvm_syncthreads?

I'm probably going to go ahead and add the TargetPrefix to the nvvm
intrinsics, but I'm not familiar enough with NVPTX to know what to do
with the others.

Thanks,
-- Justin

It's all historical, unfortunately. Before NVIDIA open sourced NVPTX, we had
the PTX target. The NVPTX target continued to accept the old PTX intrinsics to
ease compatibility. That was ~3.2, we can likely just get rid of the PTX
intrinsics now. The llvm.cuda intrinsic is an unfortunate naming quirk used
internally. This should be handled by llvm.nvvm.bar0, so it should be okay to
remove that intrinsic.

@jlebar, any issues on your end with removing all of the non-nvvm intrinsics?
> On Jul 1, 2016, at 3:01 PM, Justin Bogner <mail at justinbogner.com>
wrote:
> 
> Justins:
> 
> I noticed that the intrinsics in IntrinsicsNVVM don't specify a
> TargetPrefix. This seems like a simple omission, so I was going to
> simply throw a `let TargetPrefix = "nvvm" ` block around them,
but this
> doesn't quite work.
> 
> There seem to be three prefixes that are used in this file. About 900
> are int_nvvm_*, 30 are int_ptx_*, and 1 is int_cuda. It isn't clear to
> me if this inconsistency is intentional or warranted - should these all
> be named int_nvvm_*? Is there a good reason to differentiate int_ptx_*?
> Why does __syncthreads map to int_cuda_syncthreads, rather than
> int_nvvm_syncthreads?
> 
> I'm probably going to go ahead and add the TargetPrefix to the nvvm
> intrinsics, but I'm not familiar enough with NVPTX to know what to do
> with the others.
> 
> Thanks,
> -- Justin
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may
contain
confidential information.  Any unauthorized review, use, disclosure or
distribution
is prohibited.  If you are not the intended recipient, please contact the sender
by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------

> @jlebar, any issues on your end with removing all of the non-nvvm
intrinsics?
I don't think so, if the functionality is all there from the nvvm
intrinsics.  Some if it may involve clang changes, which I'm not
exactly volunteering to do, but they should be simple.

On Fri, Jul 1, 2016 at 2:35 PM, Justin Holewinski
<jholewinski at nvidia.com> wrote:
> It's all historical, unfortunately. Before NVIDIA open sourced NVPTX,
we had the PTX target. The NVPTX target continued to accept the old PTX
intrinsics to ease compatibility. That was ~3.2, we can likely just get rid of
the PTX intrinsics now. The llvm.cuda intrinsic is an unfortunate naming quirk
used internally. This should be handled by llvm.nvvm.bar0, so it should be okay
to remove that intrinsic.
>
> @jlebar, any issues on your end with removing all of the non-nvvm
intrinsics?
>
>> On Jul 1, 2016, at 3:01 PM, Justin Bogner <mail at
justinbogner.com> wrote:
>>
>> Justins:
>>
>> I noticed that the intrinsics in IntrinsicsNVVM don't specify a
>> TargetPrefix. This seems like a simple omission, so I was going to
>> simply throw a `let TargetPrefix = "nvvm" ` block around
them, but this
>> doesn't quite work.
>>
>> There seem to be three prefixes that are used in this file. About 900
>> are int_nvvm_*, 30 are int_ptx_*, and 1 is int_cuda. It isn't clear
to
>> me if this inconsistency is intentional or warranted - should these all
>> be named int_nvvm_*? Is there a good reason to differentiate int_ptx_*?
>> Why does __syncthreads map to int_cuda_syncthreads, rather than
>> int_nvvm_syncthreads?
>>
>> I'm probably going to go ahead and add the TargetPrefix to the nvvm
>> intrinsics, but I'm not familiar enough with NVPTX to know what to
do
>> with the others.
>>
>> Thanks,
>> -- Justin
>
-----------------------------------------------------------------------------------
> This email message is for the sole use of the intended recipient(s) and may
contain
> confidential information.  Any unauthorized review, use, disclosure or
distribution
> is prohibited.  If you are not the intended recipient, please contact the
sender by
> reply email and destroy all copies of the original message.
>
-----------------------------------------------------------------------------------