LLVM clang [3.9.0,9.0.0) (and so likely also Xcode clang <11.4) defined the _mm256_maskz_cvtps_ph intrinsic as 2-argument. Use the equivalent intrinsic _mm256_maskz_cvt_roundps_ph instead since clang has always defined it as 3-argument. https://trac.macports.org/ticket/67802 diff --git a/src/corelib/global/qfloat16.cpp b/src/corelib/global/qfloat16.cpp --- src/corelib/global/qfloat16.cpp +++ src/corelib/global/qfloat16.cpp @@ -176,9 +176,9 @@ void qFloatToFloat16_tail_avx256(quint16 *out, const float *in, qsizetype len) noexcept { __mmask16 mask = _bzhi_u32(-1, len); __m256 f32 = _mm256_maskz_loadu_ps(mask, in ); - __m128i f16 = _mm256_maskz_cvtps_ph(mask, f32, _MM_FROUND_TO_NEAREST_INT); + __m128i f16 = _mm256_maskz_cvt_roundps_ph(mask, f32, _MM_FROUND_TO_NEAREST_INT); _mm_mask_storeu_epi16(out, mask, f16); }; static QT_FUNCTION_TARGET(ARCH_SKYLAKE_AVX512)