src/cpu/x86/vm/vm_version_x86.cpp

*** 501,510 ****
--- 501,511 ----
      VM_Version::clean_cpuFeatures();
      UseAVX = saved_useavx;
      UseSSE = saved_usesse;
  
      __ bind(wrapup);
+     __ vzeroupper();
      __ popf();
      __ pop(rsi);
      __ pop(rbx);
      __ pop(rbp);
      __ ret(0);
*** 916,935 ****
    if (MaxVectorSize > 0) {
      if (!is_power_of_2(MaxVectorSize)) {
        warning("MaxVectorSize must be a power of 2");
        FLAG_SET_DEFAULT(MaxVectorSize, 64);
      }
!     if (MaxVectorSize > 64) {
!       FLAG_SET_DEFAULT(MaxVectorSize, 64);
      }
!     if (MaxVectorSize > 16 && (UseAVX == 0 || !os_supports_avx_vectors())) {
        // 32 bytes vectors (in YMM) are only supported with AVX+
        FLAG_SET_DEFAULT(MaxVectorSize, 16);
      }
!     if (UseSSE < 2) {
!       // Vectors (in XMM) are only supported with SSE2+
!       FLAG_SET_DEFAULT(MaxVectorSize, 0);
      }
  #if defined(COMPILER2) && defined(ASSERT)
      if (supports_avx() && PrintMiscellaneous && Verbose && TraceNewVectors) {
        tty->print_cr("State of YMM registers after signal handle:");
        int nreg = 2 LP64_ONLY(+2);
--- 917,956 ----
    if (MaxVectorSize > 0) {
      if (!is_power_of_2(MaxVectorSize)) {
        warning("MaxVectorSize must be a power of 2");
        FLAG_SET_DEFAULT(MaxVectorSize, 64);
      }
!     if (UseSSE < 2) {
!       // Vectors (in XMM) are only supported with SSE2+
!       if (MaxVectorSize > 0) {
!         if (!FLAG_IS_DEFAULT(MaxVectorSize))
!           warning("MaxVectorSize must be 0");
!         FLAG_SET_DEFAULT(MaxVectorSize, 0);
        }
!     }
!     else if (UseAVX == 0 || !os_supports_avx_vectors()) {
        // 32 bytes vectors (in YMM) are only supported with AVX+
+       if (MaxVectorSize > 16) {
+         if (!FLAG_IS_DEFAULT(MaxVectorSize))
+           warning("MaxVectorSize must be <= 16");
          FLAG_SET_DEFAULT(MaxVectorSize, 16);
        }
!     }
!     else if (UseAVX == 1 || UseAVX == 2) {
!       // 64 bytes vectors (in ZMM) are only supported with AVX 3
!       if (MaxVectorSize > 32) {
!         if (!FLAG_IS_DEFAULT(MaxVectorSize))
!           warning("MaxVectorSize must be <= 32");
!         FLAG_SET_DEFAULT(MaxVectorSize, 32);
!       }
!     }
!     else if (UseAVX > 2 ) {
!       if (MaxVectorSize > 64) {
!         if (!FLAG_IS_DEFAULT(MaxVectorSize))
!           warning("MaxVectorSize must be <= 64");
!         FLAG_SET_DEFAULT(MaxVectorSize, 64);
!       }
      }
  #if defined(COMPILER2) && defined(ASSERT)
      if (supports_avx() && PrintMiscellaneous && Verbose && TraceNewVectors) {
        tty->print_cr("State of YMM registers after signal handle:");
        int nreg = 2 LP64_ONLY(+2);
*** 1149,1159 ****
--- 1170,1188 ----
        }
      }
      if(FLAG_IS_DEFAULT(AllocatePrefetchInstr) && supports_3dnow_prefetch()) {
        AllocatePrefetchInstr = 3;
      }
+     if ((cpu_family() == 0x06) &&
+         ((extended_cpu_model() == 0x57) ||   // Xeon Phi 3200/5200/7200
+          (extended_cpu_model() == 0x85))) {  // Future Xeon Phi
+       if (FLAG_IS_DEFAULT(UseVzeroupper)) {
+         FLAG_SET_DEFAULT(UseVzeroupper, false);
+       }
      } 
+   }
+ 
  
  #ifdef _LP64
    if (UseSSE42Intrinsics) {
      if (FLAG_IS_DEFAULT(UseVectorizedMismatchIntrinsic)) {
        UseVectorizedMismatchIntrinsic = true;