x86: Disable AVX-512 if zmm XCR0 flags are not set

Signed-off-by: Bradley Wood <bradley.wood@ibm.com>
eclipse-omr · Nov 27, 2024 · 09f2f51 · 09f2f51
1 parent 57b5fda
commit 09f2f51
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Showing 2 changed files with 54 additions and 8 deletions.
diff --git a/compiler/x/env/OMRCPU.cpp b/compiler/x/env/OMRCPU.cpp
@@ -64,11 +64,34 @@ OMR::X86::CPU::detect(OMRPortLibrary * const omrPortLib)
 
    if (TRUE == omrsysinfo_processor_has_feature(&processorDescription, OMR_FEATURE_X86_OSXSAVE))
       {
-      static const bool disableAVX = feGetEnv("TR_DisableAVX") != NULL;
-      if (((6 & _xgetbv(0)) != 6) || disableAVX) // '6' = mask for XCR0[2:1]='11b' (XMM state and YMM state are enabled)
+      // Check XCRO register for OS support of xmm/ymm/zmm
+      // '6' = mask for XCR0[2:1]='11b' (XMM state and YMM state are enabled)
+      const bool disableAVX = ((6 & _xgetbv(0)) != 6);
+
+      // 'e6' = (mask for XCR0[7:5]='111b' (Opmask, ZMM_Hi256, Hi16_ZMM) + XCR0[2:1]='11b' (XMM/YMM))
+      const bool 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 OSXSAVE if not enabled via CR0
-         omrsysinfo_processor_set_feature(&processorDescription, OMR_FEATURE_X86_OSXSAVE, FALSE);
+         // 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);
          }
       }
 

diff --git a/compiler/x/runtime/X86Runtime.hpp b/compiler/x/runtime/X86Runtime.hpp
@@ -90,11 +90,34 @@ inline bool jitGetCPUID(TR_X86CPUIDBuffer* pBuffer)
       // Check for XSAVE
       if(pBuffer->_featureFlags2 & TR_OSXSAVE)
          {
-         static const bool disableAVX = feGetEnv("TR_DisableAVX") != NULL;
-         if(((6 & _xgetbv(0)) != 6) || disableAVX) // '6' = mask for XCR0[2:1]='11b' (XMM state and YMM state are enabled)
+         // Check XCRO register for OS support of xmm/ymm/zmm
+         // '6' = mask for XCR0[2:1]='11b' (XMM state and YMM state are enabled)
+         static const bool disableAVX = ((6 & _xgetbv(0)) != 6);
+
+         // 'e6' = (mask for XCR0[7:5]='111b' (Opmask, ZMM_Hi256, Hi16_ZMM) + XCR0[2:1]='11b' (XMM/YMM))
+         static const bool disableAVX512 = ((0xe6 & _xgetbv(0)) != 0xe6);
+
+         if(disableAVX)
+            {
+            // Unset AVX/AVX2 if not enabled via CR0 or otherwise disabled
+            pBuffer->_featureFlags2 &= ~TR_AVX;
+            pBuffer->_featureFlags8 &= ~TR_AVX2;
+            }
+
+         if (disableAVX512)
             {
-            // Unset OSXSAVE if not enabled via CR0
-            pBuffer->_featureFlags2 &= ~TR_OSXSAVE;
+            // Unset AVX-512 if not enabled via CR0 or otherwise disabled
+            // If other AVX-512 extensions are supported in the old cpuid API, they need to be disabled here
+            pBuffer->_featureFlags8 &= ~TR_AVX512F;
+            pBuffer->_featureFlags8 &= ~TR_AVX512VL;
+            pBuffer->_featureFlags8 &= ~TR_AVX512BW;
+            pBuffer->_featureFlags8 &= ~TR_AVX512CD;
+            pBuffer->_featureFlags8 &= ~TR_AVX512DQ;
+            pBuffer->_featureFlags8 &= ~TR_AVX512_BITALG;
+            pBuffer->_featureFlags8 &= ~TR_AVX512_VBMI;
+            pBuffer->_featureFlags8 &= ~TR_AVX512_VBMI2;
+            pBuffer->_featureFlags8 &= ~TR_AVX512_VNNI;
+            pBuffer->_featureFlags8 &= ~TR_AVX512_VPOPCNTDQ;
             }
          }