https://bugs.freedesktop.org/show_bug.cgi?id=68297
Priority: medium Bug ID: 68297 Assignee: mesa-dev@lists.freedesktop.org Summary: Mesa tries to detect AVX support and fails horribly Severity: major Classification: Unclassified OS: Linux (All) Reporter: delr...@gmail.com Hardware: x86-64 (AMD64) Status: NEW Version: git Component: Other Product: Mesa src/gallium/auxiliary/util/u_cpu_detect.c: util_cpu_caps.has_avx = ((regs2[2] >> 28) & 1) && // AVX This is wrong. To check for AVX support, you need to: 1. Check if the AVX bit is set in cpuid (DONE) 2. Check if the XSAVE bit is set in cpuid (NOT DONE) 3. Check if xgetbv with ecx=0 & XFEATURE_ENABLED_MASK == XFEATURE_ENABLED_MASK (NOT DONE) See, for example: https://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86Subtarget.cpp?r1=180991&r2=180990&pathrev=180991 https://code.google.com/p/dolphin-emu/source/detail?r=377202b9f6154ae56c5b2f0a45e235ceaeb6da9c Intel have some reference material about that but software.intel.com seems to be down at the moment. When trying to run llvmpipe on a machine with hardware AVX support but no kernel support for it, it currently SIGILLs. -- You are receiving this mail because: You are the assignee for the bug.
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