RFR (M): 8150767: Update for x86 SHA Extensions enabling

[Vladimir Kozlov]

Very nice, Vivek!!!

Did you run tests with both 32- and 64-bit VMs?

Small notes:

In vm_version_x86.hpp spacing are not aligned in next line:

    static bool supports_avxonly()    { return ((supports_avx2() || 
supports_avx()) && !supports_evex()); }
+  static bool supports_sha()      { return (_features & CPU_SHA) != 0; }

Flags setting code in vm_version_x86.cpp should be like this (you can 
check supports_sha() only once, don't split '} else {' line, set UseSHA 
false if all intrinsics flags are false (I included UseSHA512Intrinsics 
for future) ):

   if (supports_sha()) {
     if (FLAG_IS_DEFAULT(UseSHA)) {
       UseSHA = true;
     }
   } else if (UseSHA) {
     warning("SHA instructions are not available on this CPU");
     FLAG_SET_DEFAULT(UseSHA, false);
   }

   if (UseSHA) {
     if (FLAG_IS_DEFAULT(UseSHA1Intrinsics)) {
       FLAG_SET_DEFAULT(UseSHA1Intrinsics, true);
     }
   } else if (UseSHA1Intrinsics) {
     warning("Intrinsics for SHA-1 crypto hash functions not available 
on this CPU.");
     FLAG_SET_DEFAULT(UseSHA1Intrinsics, false);
   }

   if (UseSHA) {
     if (FLAG_IS_DEFAULT(UseSHA256Intrinsics)) {
       FLAG_SET_DEFAULT(UseSHA256Intrinsics, true);
     }
   } else if (UseSHA256Intrinsics) {
     warning("Intrinsics for SHA-224 and SHA-256 crypto hash functions 
not available on this CPU.");
     FLAG_SET_DEFAULT(UseSHA256Intrinsics, false);
   }

   if (UseSHA512Intrinsics) {
     warning("Intrinsics for SHA-384 and SHA-512 crypto hash functions 
not available on this CPU.");
     FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
   }

   if (!(UseSHA1Intrinsics || UseSHA256Intrinsics || UseSHA512Intrinsics)) {
     FLAG_SET_DEFAULT(UseSHA, false);
   }


Thanks,
Vladimir

On 2/26/16 4:37 PM, Deshpande, Vivek R wrote:
> Hi all
>
> I would like to contribute a patch which optimizesSHA-1 andSHA-256 for
> 64 and 32 bitX86architecture using Intel SHA extensions.
>
> Could you please review and sponsor this patch.
>
> Bug-id:
>
> https://bugs.openjdk.java.net/browse/JDK-8150767
> webrev:
>
> http://cr.openjdk.java.net/~vdeshpande/SHANI/8150767/webrev.00/
>
> Thanks and regards,
>
> Vivek
>