py-pytorch: variant +mps causes build failures for 10.12 and 10.13

[mascguy (Christopher Nielsen)]

The latest update to this port added support for Metal Performance Shaders, via variant +mps. And that's enabled by default.

However, builds are now failing on 10.12 and 10.13, with the following compilation error:

[  0%] Building CXX object third_party/fbgemm/asmjit/CMakeFiles/asmjit.dir/src/asmjit/core/archtraits.cpp.o
In file included from py39-pytorch/work/pytorch-1.12.0/third_party/fbgemm/third_party/asmjit/src/asmjit/core/archtraits.cpp:25:
In file included from py39-pytorch/work/pytorch-1.12.0/third_party/fbgemm/third_party/asmjit/src/asmjit/core/../core/archtraits.h:28:
py39-pytorch/work/pytorch-1.12.0/third_party/fbgemm/third_party/asmjit/src/asmjit/core/../core/operand.h:910:79:
error: use of bitwise '&' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
  static inline bool isGp(const Operand_& op, uint32_t rId) noexcept { return isGp(op) & (op.id() == rId); }
                                                                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~
                                                                                       &&

Example builds, for py39-pytorch:

• ​https://build.macports.org/builders/ports-10.12_x86_64-builder/builds/195750/steps/install-port/logs/stdio
• ​https://build.macports.org/builders/ports-10.13_x86_64-builder/builds/159737/steps/install-port/logs/stdio

It appears (?) that MPS functionality is only present in 10.13 and later. Assuming that's the case, we shouldn't declare the variant for 10.12 and earlier.

As for the current failure: Presumably we should be able to ensure -Wbitwise-instead-of-logical is simply a warning, rather than an error.

[Christopher Nielsen <mascguy@…>]

In 217f82b3d74997385429448e06addc1322d09fb3/macports-ports (master):

py-pytorch: mps: only enable for 10.13 and later

• Also disable compilation error bitwise-instead-of-logical

See: #65682

[essandess (Steve Smith)]

Replying to Christopher Nielsen <mascguy@…>:

In 217f82b3d74997385429448e06addc1322d09fb3/macports-ports (master):

py-pytorch: mps: only enable for 10.13 and later

• Also disable compilation error bitwise-instead-of-logical

See: #65682

Should this be revbumped because there's a compilation change?

[mascguy (Christopher Nielsen)]

Replying to essandess:

Should this be revbumped because there's a compilation change?

No, as we're not materially changing anything. Rather, we're simply ensuring that builds don't fail, for the bitwise-instead-of-logical case.

[mascguy (Christopher Nielsen)]

Still failing, might be fixable by specifying the cxx standard though.

[Christopher Nielsen <mascguy@…>]

In be5cf4a21f14f2df6d65da41bc596ace97126785/macports-ports (master):

py-pytorch: pass compiler flags via CMAKE_CXX_FLAGS
See: 217f82b3d74997385429448e06addc1322d09fb3/macports-ports
Fixes: #65682

[Christopher Nielsen <mascguy@…>]

In 0c7f7c966283cd32f7910b3ad4189b667cd189da/macports-ports (master):

py-pytorch: use -Wno-error, for no-bitwise-instead-of-logical
See: be5cf4a21f14f2df6d65da41bc596ace97126785/macports-ports
Fixes: #65682

[mascguy (Christopher Nielsen)]

Steve, at the risk of jinxing myself, the builds look good so far. And if nothing else, the bitwise failure is fixed.

I also queued 10.12 and 10.13 rebuilds, for py-torchaudio, py-pytorch-ligtning, and py-fairseq.