KhronosGroup / KhronosGroup/SPIR

[[cl::max_size]] does not work for all specified pointer/ref types

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Dominant language
C++
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Description

OpenCL C++ specification:

This attribute can be provided with a kernel argument of type constant_ptr<T>, constant<T>*, constant<T>&, local_ptr<T>, local<T>*, local<T>&.

#include <opencl_memory>

template <typename T>
struct local_ptr_test
{
    __local T* ptr;
};

typedef local_ptr_test<int> local_int_test;

kernel void foo0([[cl::max_size(1)]] local_ptr_test<int> arg) { }


kernel void foo1([[cl::max_size(1)]] cl::local_ptr<int> arg) { }
kernel void foo2([[cl::max_size(1)]] cl::local<int>* arg) { }
kernel void foo3([[cl::max_size(1)]] cl::local<int>& arg) { }

kernel void foo4([[cl::max_size(1)]] cl::constant_ptr<int> arg) { }
kernel void foo5([[cl::max_size(1)]] cl::constant<int>* arg) { }
kernel void foo6([[cl::max_size(1)]] cl::constant<int>& arg) { }

(foo0 is a kernel from https://github.com/KhronosGroup/SPIR/blob/spirv-1.1/test/OpenCL/OpenCL22/attributes/TestBasicAttributes_max_size.cl)

max_size.cl:14:57: error: max_size attribute only applies to kernel paremeters which are in local or constant address space
kernel void foo1([[cl::max_size(1)]] cl::local_ptr<int> arg) { }
                                                        ^
max_size.cl:16:54: error: max_size attribute only applies to kernel paremeters which are in local or constant address space
kernel void foo3([[cl::max_size(1)]] cl::local<int>& arg) { }
                                                     ^
max_size.cl:18:60: error: max_size attribute only applies to kernel paremeters which are in local or constant address space
kernel void foo4([[cl::max_size(1)]] cl::constant_ptr<int> arg) { }
                                                           ^
max_size.cl:20:57: error: max_size attribute only applies to kernel paremeters which are in local or constant address space
kernel void foo6([[cl::max_size(1)]] cl::constant<int>& arg) { }
                                                        ^
4 errors generated.

I.e. the attribute works with cl::local<int>* and cl::constant<int>*.

(Also there is a typo (paremeters) in error messages)

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the diagnostics with the examples in test/OpenCL/OpenCL22/attributes/TestBasicAttributes_max_size.cl, especially the pointer and reference forms listed in the issue. Trace the compiler's max_size attribute validation for kernel parameters. Done means all specified local and constant pointer/reference types are accepted consistently, while the diagnostic typo is corrected.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
38/100

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