qt6-qtbase @6.4.3_1: Fail to compile on 10.14 _mm256_maskz_cvtps_ph() called with wrong number of args

[macportsraf]

While testing a tiny change to the qtkeychain Portfile, the qt6-qtbase port failed to compile. It calls the _mm256_maskz_cvtps_ph() function with 3 arguments, but it's defined with 2 arguments in /Library/Developer/CommandLineTools/usr/lib/clang/11.0.0/include/avx512vlintrin.h.

    :info:build /opt/local/var/macports/build/...//qfloat16.cpp:180:19: error: no matching function for call to '_mm256_maskz_cvtps_ph'
    :info:build     __m128i f16 = _mm256_maskz_cvtps_ph(mask, f32, _MM_FROUND_TO_NEAREST_INT);
    :info:build                   ^~~~~~~~~~~~~~~~~~~~~
    :info:build /Library/Developer/CommandLineTools/usr/lib/clang/11.0.0/include/avx512vlintrin.h:8463:1: note: candidate function not viable: requires 2 arguments, but 3 were provided
    :info:build _mm256_maskz_cvtps_ph ( __mmask8 __U, __m256 __A)
    :info:build ^
    :info:build 1 error generated.

macOS 10.14.6 18G6032 x86_64

Xcode 11.3 11C29

[macportsraf]

main.log

[chrstphrchvz (Christopher Chavez)]

LLVM Clang since 3.9.0 (​https://github.com/llvm/llvm-project/commit/9e7d0a98fa26) but before 9.0.0 (​https://github.com/llvm/llvm-project/commit/6d9fb68c536d, and so likely also Xcode Clang before 11.4) had defined _mm256_maskz_cvtps_ph as 2-argument (and apparently so had Intel for a time, but not anymore). It should be okay to use the equivalent _mm256_maskz_cvt_roundps_ph intrinsic which Clang has always defined as 3-argument: ​https://github.com/macports/macports-ports/pull/19627

However ​https://github.com/macports/macports-ports/pull/19407 already proposed disabling this and other code which does not build on 10.14.

[chrstphrchvz (Christopher Chavez)]

In c5d2c7e52f9c552a6079add1894c66c322a10eab/macports-ports (master):

qt6-qtbase: attempt to fix build on 10.14

Fixes: #67802