src/java.base/share/classes/sun/security/provider/SHA2.java

rev 12262 : 8076112: Add @HotSpotIntrinsicCandidate annotation to indicate methods for which Java Runtime has intrinsics
Summary: Annotate possibly intrinsified methods with @HotSpotIntrinsicCandidate. Add checks omitted by intrinsics to the library code. Add CheckIntrinsics flags to check consistency of intrinsics.
Reviewed-by: jrose, kvn, thartmann, vlivanov, abuckley, darcy, ascarpino, briangoetz, alanb, aph, dnsimon

*** 23,32 ****
--- 23,35 ----
   * questions.
   */
  
  package sun.security.provider;
  
+ import java.util.Objects;
+ 
+ import jdk.internal.HotSpotIntrinsicCandidate;
  import static sun.security.provider.ByteArrayAccess.*;
  
  /**
   * This class implements the Secure Hash Algorithm SHA-256 developed by
   * the National Institute of Standards and Technology along with the
*** 184,195 ****
--- 187,217 ----
  
      /**
       * Process the current block to update the state variable state.
       */
      void implCompress(byte[] buf, int ofs) {
+         implCompressCheck(buf, ofs);
+         implCompress0(buf, ofs);
+     }
+ 
+     private void implCompressCheck(byte[] buf, int ofs) {
+         Objects.requireNonNull(buf);
+ 
+         // The checks performed by the method 'b2iBig64'
+         // are sufficient for the case when the method
+         // 'implCompressImpl' is replaced with a compiler
+         // intrinsic.
          b2iBig64(buf, ofs, W);
+     }
  
+     // The method 'implCompressImpl' seems not to use its parameters.
+     // The method can, however, be replaced with a compiler intrinsic
+     // that operates directly on the array 'buf' (starting from
+     // offset 'ofs') and not on array 'W', therefore 'buf' and 'ofs'
+     // must be passed as parameter to the method.
+     @HotSpotIntrinsicCandidate
+     private void implCompress0(byte[] buf, int ofs) {
          // The first 16 ints are from the byte stream, compute the rest of
          // the W[]'s
          for (int t = 16; t < ITERATION; t++) {
              W[t] = lf_delta1(W[t-2]) + W[t-7] + lf_delta0(W[t-15])
                     + W[t-16];