powHit costing

data/shared/src/main/scala/sigma/ast/SMethod.scala

@@ -298,7 +298,7 @@ object SMethod {
     * @return an instance of [[SMethod]] which may contain generic type variables in the
     *         signature (see SMethod.stype). As a result `specializeFor` is called by
     *         deserializer to obtain monomorphic method descriptor.
-    * @consensus this is method is used in [[sigmastate.serialization.MethodCallSerializer]]
+    * @consensus this is method is used in [[sigma.serialization.MethodCallSerializer]]
     *            `parse` method and hence it is part of consensus protocol
     */
   def fromIds(typeId: Byte, methodId: Byte): SMethod = {

data/shared/src/main/scala/sigma/ast/methods.scala

@@ -1512,21 +1512,23 @@ case object SGlobalMethods extends MonoTypeMethods {
     .withInfo(Xor, "Byte-wise XOR of two collections of bytes",
       ArgInfo("left", "left operand"), ArgInfo("right", "right operand"))
 
+  private def powHitCostKind = PerItemCost(baseCost = JitCost(10), perChunkCost = JitCost(10), chunkSize = 128)
+
   lazy val powHitMethod = SMethod(
-    this, "powHit", SFunc(Array(SGlobal, SInt, SByteArray, SByteArray, SByteArray, SInt), SBigInt), 3, GroupGenerator.costKind) // todo: cost
+    this, "powHit", SFunc(Array(SGlobal, SInt, SByteArray, SByteArray, SByteArray, SInt), SBigInt), 3, powHitCostKind)
     .withIRInfo(MethodCallIrBuilder)
     .withInfo(MethodCall,
       "Calculating Proof-of-Work hit (Autolykos 2 hash value) for custom Autolykos 2 function",
       ArgInfo("k", "k parameter of Autolykos 2 (number of inputs in k-sum problem)"),
       ArgInfo("msg", "Message to calculate Autolykos hash 2 for"),
       ArgInfo("nonce", "Nonce used to pad the message to get Proof-of-Work hash function output with desirable properties"),
-      ArgInfo("h", "PoW protocol specific padding (e.g. block height in Ergo)"),
+      ArgInfo("h", "PoW protocol specific padding for table uniqueness (e.g. block height in Ergo)"),
       ArgInfo("N", "Size of table filled with pseudo-random data to find k elements in"),
     )
 
   def powHit_eval(mc: MethodCall, G: SigmaDslBuilder, k: Int, msg: Coll[Byte], nonce: Coll[Byte], h: Coll[Byte], N: Int)
                   (implicit E: ErgoTreeEvaluator): BigInt = {
-    E.addSeqCost(Xor.costKind, msg.length, Xor.opDesc) { () => // todo: proper costing
+    E.addSeqCost(powHitCostKind, k * (msg.length + nonce.length + h.length), powHitMethod.opDesc) { () =>
       CBigInt(Autolykos2PowValidation.hitForVersion2ForMessage(k, msg.toArray, nonce.toArray, h.toArray, N).bigInteger)
     }
   }

sc/shared/src/test/scala/sigma/LanguageSpecificationV6.scala

@@ -1,10 +1,13 @@
 package sigma
 
-import sigma.ast.{Apply, Downcast, FixedCost, FixedCostItem, FuncValue, GetVar, JitCost, OptionGet, SBigInt, SByte, SInt, SLong, SShort, ValUse}
+import sigma.ast.SCollection.SByteArray
+import sigma.ast.{Apply, BlockValue, Downcast, FixedCost, FixedCostItem, FuncValue, GetVar, Global, JitCost, MethodCall, OptionGet, SBigInt, SByte, SCollection, SGlobal, SGlobalMethods, SInt, SLong, SPair, SShort, SelectField, ValDef, ValUse, Value}
 import sigma.data.{CBigInt, ExactNumeric}
 import sigma.eval.SigmaDsl
+import sigma.pow.Autolykos2PowValidation
 import sigma.util.Extensions.{BooleanOps, ByteOps, IntOps, LongOps}
 import sigmastate.exceptions.MethodNotFound
+import sigma.BigIntRType
 
 import java.math.BigInteger
 import scala.util.Success
@@ -115,10 +118,6 @@ class LanguageSpecificationV6 extends LanguageSpecificationBase { suite =>
     }
   }
 
-  property("") {
-
-  }
-
   property("Int methods equivalence (new features)") {
     if (activatedVersionInTests < VersionContext.V6SoftForkVersion) {
       // NOTE, for such versions the new features are not supported