src/cpu/x86/vm/vm_version_x86.cpp

@@ -576,11 +576,11 @@
     // HT processor could be installed on a system which doesn't support HT.
     _features &= ~CPU_HT;
   }
 
   char buf[256];
-  jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+  jio_snprintf(buf, sizeof(buf), "(%u cores per cpu, %u threads per core) family %d model %d stepping %d%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
                cores_per_cpu(), threads_per_core(),
                cpu_family(), _model, _stepping,
                (supports_cmov() ? ", cmov" : ""),
                (supports_cmpxchg8() ? ", cx8" : ""),
                (supports_fxsr() ? ", fxsr" : ""),

@@ -608,11 +608,12 @@
                (supports_tscinv() ? ", tscinv": ""),
                (supports_bmi1() ? ", bmi1" : ""),
                (supports_bmi2() ? ", bmi2" : ""),
                (supports_adx() ? ", adx" : ""),
                (supports_evex() ? ", evex" : ""),
-               (supports_sha() ? ", sha" : ""));
+               (supports_sha() ? ", sha" : ""),
+               (supports_fma() ? ", fma" : ""));
   _features_string = os::strdup(buf);
 
   // UseSSE is set to the smaller of what hardware supports and what
   // the command line requires.  I.e., you cannot set UseSSE to 2 on
   // older Pentiums which do not support it.

@@ -771,10 +772,22 @@
   if (UseAdler32Intrinsics) {
     warning("Adler32Intrinsics not available on this CPU.");
     FLAG_SET_DEFAULT(UseAdler32Intrinsics, false);
   }
 
+  if (supports_fma()) {
+    if (FLAG_IS_DEFAULT(UseFMA)) {
+      UseFMA = true;
+    }
+  }
+  else if (UseFMA) {
+    if (!FLAG_IS_DEFAULT(UseFMA))
+      warning("FMA instructions not available on this CPU");
+    FLAG_SET_DEFAULT(UseFMA, false);
+  }
+
+
   // Adjust RTM (Restricted Transactional Memory) flags
   if (!supports_rtm() && UseRTMLocking) {
     // Can't continue because UseRTMLocking affects UseBiasedLocking flag
     // setting during arguments processing. See use_biased_locking().
     // VM_Version_init() is executed after UseBiasedLocking is used