OpenJDK 8 bug when implementing muladd on ppc

add-muladd-ppc.diff

diff -r 92cb89e23f3e src/cpu/ppc/vm/stubGenerator_ppc.cpp
--- a/src/cpu/ppc/vm/stubGenerator_ppc.cpp	Tue Apr 04 02:49:51 2017 -0700
+++ b/src/cpu/ppc/vm/stubGenerator_ppc.cpp	Fri Apr 07 11:03:29 2017 -0300
@@ -2473,6 +2473,81 @@
     __ blr();
   }
 
+  /**
+  *  Arguments:
+  *
+  *  Input:
+  *   R3_ARG1    - out address
+  *   R4_ARG2    - in address
+  *   R5_ARG3    - offset
+  *   R6_ARG4    - len
+  *   R7_ARG5    - k
+  *  Output:
+  *   R3_RET     - carry
+  */
+  address generate_mulAdd() {
+    __ align(CodeEntryAlignment);
+    StubCodeMark mark(this, "StubRoutines", "mulAdd");
+
+    address start = __ function_entry();
+
+    // args
+    const Register out     = R3_ARG1;
+    const Register in      = R4_ARG2;
+    const Register offset  = R5_ARG3;
+    const Register len     = R6_ARG4;
+    const Register k       = R7_ARG5;
+
+    // output
+    const Register ret     = R3_RET;
+
+    // temporaries
+    const Register a       = R8;
+    const Register b       = R9;
+    const Register carry   = R10;
+
+    // Labels
+    Label MULADD_LOOP, SKIP;
+
+    // Prepare variables
+    __ li     (carry,   0);
+
+    // Make sure length is positive.
+    __ cmpdi  (CCR0, len, 0);
+    __ ble    (CCR0, SKIP);
+
+    __ addi   (offset,  offset,  -1   );
+
+    __ clrldi (k,       k,       32   );
+    __ mtctr  (len);
+    __ addi   (len,     len,     -1   );
+    // offset and len will be adjusted to 4 bytes
+    __ sldi   (offset,  offset,  2    );
+    __ sldi   (len,     len,     2    );
+
+    // Main loop
+    __ bind(MULADD_LOOP);
+    __ lwzx   (a,       len,     in   );
+    __ lwzx   (b,       offset,  out  );
+    // Using mulld instead of mullw because the parameters need to be
+    // considered as unsigned even if bit 31 is set (aka negative int)
+    __ mulld  (a,       a,       k    );
+    __ add    (b,       carry,   b    );
+    __ add    (b,       a,       b    );
+    __ stwx   (b,       offset,  out  );
+    __ srdi   (carry,   b,       32   );
+    __ addi   (offset,  offset,  -4   );
+    __ addi   (len,     len,     -4   );
+    __ bdnz   (MULADD_LOOP);
+
+    __ bind(SKIP);
+    __ mr     (ret,     carry         );
+
+    __ blr();
+
+    return start;
+  }
+
   // Initialization
   void generate_initial() {
     // Generates all stubs and initializes the entry points
@@ -2518,6 +2593,9 @@
     generate_safefetch("SafeFetchN", sizeof(intptr_t), &StubRoutines::_safefetchN_entry,
                                                        &StubRoutines::_safefetchN_fault_pc,
                                                        &StubRoutines::_safefetchN_continuation_pc);
+    if (UseMulAddIntrinsic) {
+      StubRoutines::_mulAdd = generate_mulAdd();
+    }
 
     if (UseAESIntrinsics) {
       StubRoutines::_aescrypt_encryptBlock = generate_aescrypt_encryptBlock();
diff -r 92cb89e23f3e src/cpu/ppc/vm/vm_version_ppc.cpp
--- a/src/cpu/ppc/vm/vm_version_ppc.cpp	Tue Apr 04 02:49:51 2017 -0700
+++ b/src/cpu/ppc/vm/vm_version_ppc.cpp	Fri Apr 07 11:03:29 2017 -0300
@@ -201,6 +201,9 @@
     FLAG_SET_DEFAULT(UseSHA512Intrinsics, false);
   }
 
+  if (FLAG_IS_DEFAULT(UseMulAddIntrinsic)) {
+    UseMulAddIntrinsic = true;
+  }
 }
 
 void VM_Version::print_features() {

TestMulAdd.java

/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

//package compiler.intrinsics.bigInteger;

import java.math.BigInteger;
import java.util.Random;

public class TestMulAdd {

    public static void main(String args[]) throws Exception {

      int n = 1;
      if (args.length >=1) {
        n = Integer.parseInt(args[0]);
      }

      BigInteger newsum = new BigInteger("0");

      BigInteger b1, newres;

      Random rand = new Random();
      long seed = System.nanoTime();
      Random rand1 = new Random();
      long seed1 = System.nanoTime();
      rand.setSeed(seed);
      rand1.setSeed(seed1);

      for (int j = 0; j < n; j++) {
        int rand_int = rand1.nextInt(3136)+32;
        b1 = new BigInteger(rand_int, rand);
        //System.out.println(b1);
        newres = b1.multiply(b1);
        newsum = newsum.add(newres);
      }
   }
}