| Summary: | dev-qt/qtbase-6.5.1-r1 emerge fail on AVX512-enabled Alder Lake CPU with march=native | ||
|---|---|---|---|
| Product: | Gentoo Linux | Reporter: | znjameswu |
| Component: | Current packages | Assignee: | Qt Bug Alias <qt> |
| Status: | UNCONFIRMED --- | ||
| Severity: | normal | ||
| Priority: | Normal | ||
| Version: | unspecified | ||
| Hardware: | All | ||
| OS: | Linux | ||
| See Also: | https://bugs.gentoo.org/show_bug.cgi?id=908420 | ||
| Whiteboard: | |||
| Package list: | Runtime testing required: | --- | |
| Attachments: |
lscpu
emerge --info build.log environment gcc -march=native -Q --help=target emerge --info '=dev-qt/qtbase-6.5.1-r1::gentoo' |
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Created attachment 865565 [details]
lscpu
Created attachment 865566 [details]
emerge --info
Created attachment 865567 [details]
build.log
Created attachment 865568 [details]
environment
Created attachment 865569 [details]
gcc -march=native -Q --help=target
Created attachment 865570 [details]
emerge --info '=dev-qt/qtbase-6.5.1-r1::gentoo'
Supplementary Info: I'm not using any (In reply to znjameswu from comment #7) Supplementary Info: I'm not using VirtualBox. The installation is on bare metal. Please file a bug upstream. |
Selected part of the error log: ``` /var/tmp/portage/dev-qt/qtbase-6.5.1-r1/work/qtbase-everywhere-src-6.5.1_build/include/QtCore/../../../qtbase-everywhere-src-6.5.1/src/corelib/global/qfloat16.h: In function ‘qfloat16 qSqrt(qfloat16)’: /var/tmp/portage/dev-qt/qtbase-6.5.1-r1/work/qtbase-everywhere-src-6.5.1_build/include/QtCore/../../../qtbase-everywhere-src-6.5.1/src/corelib/global/qfloat16.h:266:9: error: ‘__m128h’ was not declared in this scope 266 | __m128h v = _mm_set_sh(f); | ^~~~~~~ /var/tmp/portage/dev-qt/qtbase-6.5.1-r1/work/qtbase-everywhere-src-6.5.1_build/include/QtCore/../../../qtbase-everywhere-src-6.5.1/src/corelib/global/qfloat16.h:267:9: error: ‘v’ was not declared in this scope 267 | v = _mm_sqrt_sh(v, v); | ^ /var/tmp/portage/dev-qt/qtbase-6.5.1-r1/work/qtbase-everywhere-src-6.5.1_build/include/QtCore/../../../qtbase-everywhere-src-6.5.1/src/corelib/global/qfloat16.h:267:13: error: ‘_mm_sqrt_sh’ was not declared in this scope 267 | v = _mm_sqrt_sh(v, v); | ^~~~~~~~~~~ /var/tmp/portage/dev-qt/qtbase-6.5.1-r1/work/qtbase-everywhere-src-6.5.1_build/include/QtCore/../../../qtbase-everywhere-src-6.5.1/src/corelib/global/qfloat16.h:268:16: error: ‘_mm_cvtsh_h’ was not declared in this scope 268 | return _mm_cvtsh_h(v); | ^~~~~~~~~~~ ``` Reproducible: Always Steps to Reproduce: 1. Use an AVX512-enabled Intel Alder Lake (12th gen Core) machine 2. Set "march=native" in gcc flags Actual Results: Emerge failed Suspected Cause: in qtbase-6.5.1-r1/work/qtbase-everywhere-src-6.5.1/src/corelib/global/qfloat16.h:29: ``` #if defined(QT_COMPILER_SUPPORTS_F16C) && defined(__F16C__) #include <immintrin.h> #endif ``` Somehow QT_COMPILER_SUPPORTS_F16C is undef on my machine. When commented out, the manual build turns out successful Background: Alder Lake CPUs (or Intel 12th gen Core) do not officially support AVX512. However, a CooperLake-equivalent AVX512 support can be enabled on those CPUs by specific firmwares. Hence a very niche configuration.