Fix adjustment on non-aligned vectors

Author: ldematte

libs/simdvec/src/main21/java/org/elasticsearch/simdvec/internal/Int7SQVectorScorerSupplier.java

@@ -128,13 +128,15 @@ protected void bulkScoreFromSegment(
     ) {
         long firstByteOffset = (long) firstOrd * vectorPitch;
         var a = vectors.asSlice(firstByteOffset, vectorLength);
-        var aOffset = Float.intBitsToFloat(vectors.asSlice(firstByteOffset + vectorLength, Float.BYTES).get(ValueLayout.JAVA_INT, 0));
+        var aOffset = Float.intBitsToFloat(
+            vectors.asSlice(firstByteOffset + vectorLength, Float.BYTES).getAtIndex(ValueLayout.JAVA_INT_UNALIGNED, 0)
+        );
         for (int i = 0; i < numNodes; ++i) {
             var secondOrd = ordinals.getAtIndex(ValueLayout.JAVA_INT, i);
             long secondByteOffset = (long) secondOrd * vectorPitch;
             var b = vectors.asSlice(secondByteOffset, vectorLength);
             var bOffset = Float.intBitsToFloat(
-                vectors.asSlice(secondByteOffset + vectorLength, Float.BYTES).getAtIndex(ValueLayout.JAVA_INT, 0)
+                vectors.asSlice(secondByteOffset + vectorLength, Float.BYTES).getAtIndex(ValueLayout.JAVA_INT_UNALIGNED, 0)
             );
             var score = scoreFromSegments(a, aOffset, b, bOffset);
             scores.setAtIndex(ValueLayout.JAVA_FLOAT, i, score);
@@ -230,13 +232,15 @@ protected void bulkScoreFromSegment(
             Similarities.dotProduct7uBulkWithOffsets(vectors, firstVector, dims, vectorPitch, ordinals, numNodes, scores);
 
             // Java-side adjustment
-            var aOffset = Float.intBitsToFloat(vectors.asSlice(firstByteOffset + vectorLength, Float.BYTES).get(ValueLayout.JAVA_INT, 0));
+            var aOffset = Float.intBitsToFloat(
+                vectors.asSlice(firstByteOffset + vectorLength, Float.BYTES).getAtIndex(ValueLayout.JAVA_INT_UNALIGNED, 0)
+            );
             for (int i = 0; i < numNodes; ++i) {
                 var dotProduct = scores.getAtIndex(ValueLayout.JAVA_FLOAT, i);
                 var secondOrd = ordinals.getAtIndex(ValueLayout.JAVA_INT, i);
                 long secondByteOffset = (long) secondOrd * vectorPitch;
                 var bOffset = Float.intBitsToFloat(
-                    vectors.asSlice(secondByteOffset + vectorLength, Float.BYTES).getAtIndex(ValueLayout.JAVA_INT, 0)
+                    vectors.asSlice(secondByteOffset + vectorLength, Float.BYTES).getAtIndex(ValueLayout.JAVA_INT_UNALIGNED, 0)
                 );
                 float adjustedDistance = dotProduct * scoreCorrectionConstant + aOffset + bOffset;
                 scores.setAtIndex(ValueLayout.JAVA_FLOAT, i, Math.max((1 + adjustedDistance) / 2, 0f));