Check if workaround deduction guide is needed

[pfultz2]

Motivation

The deduction guides for aggregates constructors have been broken on hip as it doesnt propagate the device target from the constructor. This has been fixed on a newer compiler and the workaround is deprecated behaviour. For now, detect when this behaviour works and adjust the workaround. The MIGRAPHX_AUTO_DEDUCE can be removed on a newer version of the compiler.

Technical Details

Changelog Category

Add a CHANGELOG.md entry for any option other than Not Applicable

• • Added: New functionality.
• • Changed: Changes to existing functionality.
• • Removed: Functionality or support that has been removed. (Compared to a previous release)
• • Optimized: Component performance that has been optimized or improved.
• • Resolved Issues: Known issues from a previous version that have been resolved.
• • Not Applicable: This PR is not to be included in the changelog.

[Copilot]

Pull request overview

Updates MIGraphX’s HIP kernel compilation path to conditionally enable a workaround for broken class template argument deduction (CTAD) deduction guides on certain HIP/Clang toolchains.

Changes:

• Make MIGRAPHX_AUTO_DEDUCE conditional on a new MIGRAPHX_WORKAROUND_BROKEN_DEDUCTION_GUIDE macro.
• Introduce hip_can_compile(src, flags) to support compiling arbitrary probe sources (and refactor hip_has_flags to use it).
• Add a compile-time probe in HIP code object compilation to decide whether to define MIGRAPHX_WORKAROUND_BROKEN_DEDUCTION_GUIDE, and extend warning filtering.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
src/targets/gpu/kernels/include/migraphx/kernels/types.hpp	Makes deduction guide emission conditional (workaround vs non-workaround form).
src/targets/gpu/include/migraphx/gpu/compile_hip.hpp	Exposes new hip_can_compile helper in the GPU compile API.
src/targets/gpu/compile_hip.cpp	Implements hip_can_compile and refactors hip_has_flags to call it.
src/targets/gpu/compile_hip_code_object.cpp	Adds a compile probe to decide if the deduction-guide workaround macro should be defined; adds a warning suppression probe.

Comments suppressed due to low confidence (1)

src/targets/gpu/compile_hip.cpp:381

• hip_can_compile hardcodes arch = "gfx900", so the result depends on whether the toolchain supports that specific target rather than whether the provided source/flags are generally compilable. Since this is now a public/utility API (and is used to gate behavior), consider accepting an arch argument (or using the current device arch / a compiler-supported default like native) to avoid false failures caused by an unsupported probe arch.

bool hip_can_compile(const std::string& src, const std::vector<std::string>& flags)
{
    src_file input{"main.cpp", src};
    std::vector<src_file> srcs = {input};

    try
    {
        std::string arch = "gfx900";
        compile_hip_src(srcs, flags, arch, true);
        return true;

---

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[Copilot]

The probe uses __attribute__((device)), which may be ignored/treated as an unknown attribute by Clang in HIP mode (often only emitting a warning). If that happens, this test can compile even on compilers where the deduction guide is still broken, causing the workaround to be disabled incorrectly. Prefer using HIP’s __device__ (or a __global__ kernel) so the code is unquestionably compiled in device context.

Suggested change

	__attribute__((device)) auto f()
	__device__ auto f()

[Copilot]

hip_can_compile(test, {"-std=c++17"}) allows the probe to succeed even if the compiler only emits warnings (e.g., for unknown attributes/options), which can lead to a false “works” result and disable the workaround. Consider passing -Werror (and any other minimal flags needed) to make this feature-detection conservative (false positives are OK; false negatives are risky).

Suggested change

	static bool can_compile = hip_can_compile(test, {"-std=c++17"});
	static bool can_compile = hip_can_compile(test, {"-std=c++17", "-Werror"});

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4763      +/-   ##
===========================================
- Coverage    92.37%   92.32%   -0.04%     
===========================================
  Files          581      583       +2     
  Lines        28703    29334     +631     
===========================================
+ Hits         26512    27082     +570     
- Misses        2191     2252      +61     

see 34 files with indirect coverage changes

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