Bug#1070446: rocm-hipamd: arm64 FTBFS with glibc 2.38

[Cordell Bloor]

Tags: patch

Hi Graham,

On 2024-05-05 07:31, Graham Inggs wrote:
> As can be seen in reproducible builds [1], rocm-hipamd FTBFS on arm64
> with glibc 2.38.  I've copied what I hope is the relevant part of the
> log below.
>
> A bug was filed against glibc [2], but it seems glibc upstream do not
> consider it a bug in glibc.

There is nothing that can be done in rocm-hipamd to address this bug, 
aside from removing arm64 from the rocm-hipamd architecture list. The 
incompatibility is not with the HIP runtime, but with the HIP language. 
This is a disagreement that glibc and llvm will need to resolve between 
themselves.

> [1]https://tests.reproducible-builds.org/debian/rb-pkg/rocm-hipamd.html
> [2]https://sourceware.org/bugzilla/show_bug.cgi?id=30909
>
>
> In file included from /tmp/hip_pch.724714/hip_pch.h:1:
> In file included from
> /build/reproducible-path/rocm-hipamd-5.7.1/hip/include/hip/hip_runtime.h:62:
> In file included from
> /build/reproducible-path/rocm-hipamd-5.7.1/hipamd/include/hip/amd_detail/amd_hip_runtime.h:76:
> In file included from
> /usr/lib/gcc/aarch64-linux-gnu/13/../../../../include/c++/13/cmath:47:
> In file included from /usr/include/math.h:40:
> /usr/include/aarch64-linux-gnu/bits/math-vector.h:40:9: error: unknown
> type name '__SVFloat32_t'
>     40 | typedef __SVFloat32_t __sv_f32_t;
>        |         ^
> /usr/include/aarch64-linux-gnu/bits/math-vector.h:41:9: error: unknown
> type name '__SVFloat64_t'
>     41 | typedef __SVFloat64_t __sv_f64_t;
>        |         ^
> /usr/include/aarch64-linux-gnu/bits/math-vector.h:42:9: error: unknown
> type name '__SVBool_t'
>     42 | typedef __SVBool_t __sv_bool_t;
>        |         ^

This compilation error is when building device code when the host 
architecture is aarch64. LLVM only defines __SVFloat32_t, __SVFloat64_t 
and __SVBool_t when building host code, but not when building device 
code. To me this seems reasonable because GPUs do not support SVE 
instructions.

However, the math.h header (on aarch64 at least) is not aware of the 
concept of the distinction between host code and device code. As such, 
it fails when compiling device code. The glibc argument is that GCC 
always supports these types, but I'm not convinced. I'm curious how GCC 
handles the math headers for OpenMP GPU offloading [3].

In any case, I've attached a patch for glibc that would fix this bug. 
Perhaps my suggestion would be more palatable to upstream than the 
previously rejected patch. If not, it's up to glibc or LLVM to find a 
solution. If they cannot, then we will have to drop arm64 support for 
the HIP language.

Sincerely,
Cory Bloor

[3]: https://gcc.gnu.org/wiki/Offloading
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