Added hasBMI2() feature detection and use it to list some Celeron Haswell CPUs as non-Haswell CPUs.

core/java/src/freenet/support/CPUInformation/CPUID.java

@@ -324,6 +324,7 @@ public class CPUID {
         System.out.println("\n **More CPUInfo**");
         System.out.println("CPU model string: " + c.getCPUModelString());
         System.out.println("CPU has MMX:    " + c.hasMMX());
+        System.out.println("CPU has BMI2:   " + c.hasBMI2());
         System.out.println("CPU has SSE:    " + c.hasSSE());
         System.out.println("CPU has SSE2:   " + c.hasSSE2());
         System.out.println("CPU has SSE3:   " + c.hasSSE3());

core/java/src/freenet/support/CPUInformation/CPUIDCPUInfo.java

@@ -17,6 +17,10 @@ abstract class CPUIDCPUInfo implements CPUInfo
         return (CPUID.getEDXCPUFlags() & (1 << 23)) != 0; //EDX Bit 23
     }
 
+    public boolean hasBMI2(){
+        return (CPUID.getExtendedEBXFeatureFlags() & (1 << 8)) != 0; // Extended EBX Bit 8
+    }
+
     public boolean hasSSE(){
         return (CPUID.getEDXCPUFlags() & (1 << 25)) != 0; //EDX Bit 25
     }

core/java/src/freenet/support/CPUInformation/CPUInfo.java

@@ -22,6 +22,7 @@ public interface CPUInfo
      * @return A string indicating the vendor of the CPU.
      */
     public String getVendor();
+
     /**
      * @return A string detailing what type of CPU that is present in the machine. I.e. 'Pentium IV' etc.
      * @throws UnknownCPUException If for any reason the retrieval of the requested information
@@ -29,32 +30,39 @@ public interface CPUInfo
      * cause of the failure.
      */
     public String getCPUModelString() throws UnknownCPUException;
-    
+
     /**
-     * @return true iff the CPU support the MMX instruction set.
+     * @return true iff the CPU supports the MMX instruction set.
      */
     public boolean hasMMX();
+
     /**
-     * @return true iff the CPU support the SSE instruction set.
+     * @return true iff the CPU supports the BMI2 instruction set.
+     */
+    public boolean hasBMI2();
+
+    /**
+     * @return true iff the CPU supports the SSE instruction set.
      */
     public boolean hasSSE();
+
     /**
-     * @return true iff the CPU support the SSE2 instruction set.
+     * @return true iff the CPU supports the SSE2 instruction set.
      */
     public boolean hasSSE2();
 
     /**
-     * @return true iff the CPU support the SSE3 instruction set.
+     * @return true iff the CPU supports the SSE3 instruction set.
      */
     public boolean hasSSE3();
     
     /**
-     * @return true iff the CPU support the SSE4.1 instruction set.
+     * @return true iff the CPU supports the SSE4.1 instruction set.
      */
     public boolean hasSSE41();
 
     /**
-     * @return true iff the CPU support the SSE4.2 instruction set.
+     * @return true iff the CPU supports the SSE4.2 instruction set.
      */
     public boolean hasSSE42();
 
@@ -62,7 +70,7 @@ public interface CPUInfo
      * AMD K10 only. Not supported on Intel.
      * ref: https://en.wikipedia.org/wiki/SSE4.2#SSE4a
      *
-     * @return true iff the CPU support the SSE4A instruction set.
+     * @return true iff the CPU supports the SSE4A instruction set.
      */
     public boolean hasSSE4A();
     
@@ -105,6 +113,7 @@ public interface CPUInfo
      * @since 0.9.21
      */
     public boolean hasTBM();
+
     /**
      * @return true iff the CPU supports the AES-NI instruction set.
      * @since 0.9.14

core/java/src/freenet/support/CPUInformation/IntelInfoImpl.java

@@ -37,7 +37,13 @@ class IntelInfoImpl extends CPUIDCPUInfo implements IntelCPUInfo
     public boolean IsCoreiCompatible(){ return isCoreiCompatible; }
     public boolean IsSandyCompatible(){ return isSandyCompatible; }
     public boolean IsIvyCompatible(){ return isIvyCompatible; }
-    public boolean IsHaswellCompatible(){ return isHaswellCompatible; }
+    public boolean IsHaswellCompatible(){
+      // Some Celeron Haswell CPUs do not support BMI2, which
+      // GMP-6.0 assumes is present in all Haswell CPUs and causes
+      // crashes. Mark these CPUs as non-Haswell.
+      
+      return this.hasBMI2() && isHaswellCompatible;
+    }
     public boolean IsBroadwellCompatible(){ return isBroadwellCompatible; }
 
     public String getCPUModelString() throws UnknownCPUException