From ba7cf9aabcf5725916a7c7991d40375ff3b4e630 Mon Sep 17 00:00:00 2001 From: Bradley Wood Date: Fri, 6 Dec 2024 12:36:52 -0500 Subject: [PATCH] x86: Disable AVX/AVX-512 if XCR0 flags are not set Signed-off-by: Bradley Wood --- runtime/compiler/env/ProcessorDetection.cpp | 51 +++++++++++++++++++-- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/runtime/compiler/env/ProcessorDetection.cpp b/runtime/compiler/env/ProcessorDetection.cpp index 2142ed43560..c028fc6cabf 100644 --- a/runtime/compiler/env/ProcessorDetection.cpp +++ b/runtime/compiler/env/ProcessorDetection.cpp @@ -116,6 +116,17 @@ #include #endif +#if defined(OMR_OS_WINDOWS) && defined(TR_TARGET_X86) +#include +#elif defined(TR_TARGET_X86) +inline unsigned long long _xgetbv(unsigned int ecx) + { + unsigned int eax, edx; + __asm__ __volatile__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(ecx)); + return ((unsigned long long)edx << 32) | eax; + } +#endif + #if defined(J9ZOS390) extern "C" bool _isPSWInProblemState(); /* 390 asm stub */ #endif @@ -296,7 +307,7 @@ void TR_J9VM::initializeProcessorType() { TR_ASSERT(_compInfo,"compInfo not defined"); - + if (TR::Compiler->target.cpu.isZ()) { OMRProcessorDesc processorDescription = TR::Compiler->target.cpu.getProcessorDescription(); @@ -333,12 +344,42 @@ TR_J9VM::initializeProcessorType() { OMRProcessorDesc processorDescription = TR::Compiler->target.cpu.getProcessorDescription(); OMRPORT_ACCESS_FROM_OMRPORT(TR::Compiler->omrPortLib); - static const bool disableAVX = feGetEnv("TR_DisableAVX") != NULL; - if (disableAVX) + + bool disableAVX = true; + bool disableAVX512 = true; + + // Check XCRO register for OS support of xmm/ymm/zmm + if (TRUE == omrsysinfo_processor_has_feature(&processorDescription, OMR_FEATURE_X86_OSXSAVE)) { - omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_OSXSAVE, FALSE); + // '6' = mask for XCR0[2:1]='11b' (XMM state and YMM state are enabled) + disableAVX = ((6 & _xgetbv(0)) != 6); + // 'e6' = (mask for XCR0[7:5]='111b' (Opmask, ZMM_Hi256, Hi16_ZMM) + XCR0[2:1]='11b' (XMM/YMM)) + disableAVX512 = ((0xe6 & _xgetbv(0)) != 0xe6); } - + + if(disableAVX) + { + // Unset AVX/AVX2 if not enabled via CR0 or otherwise disabled + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX2, FALSE); + } + + if (disableAVX512) + { + // Unset AVX-512 if not enabled via CR0 or otherwise disabled + // If other AVX-512 extensions are supported in the port library, they need to be disabled here + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512F, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512VL, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512BW, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512CD, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512DQ, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512_BITALG, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512_VBMI, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512_VBMI2, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512_VNNI, FALSE); + omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_AVX512_VPOPCNTDQ, FALSE); + } + TR::Compiler->target.cpu = TR::CPU::customize(processorDescription); const char *vendor = TR::Compiler->target.cpu.getProcessorVendorId();