Replaced hard-coded fees for precompile gas costs with constants from ethereum-common

Author: holgerd77

lib/precompiled/05-modexp.js

@@ -1,8 +1,9 @@
 const utils = require('ethereumjs-util')
 const BN = utils.BN
 const error = require('../constants.js').ERROR
+const fees = require('ethereum-common')
 
-const Gquaddivisor = 20
+const Gquaddivisor = fees.modexpGquaddivisor.v
 
 function multComplexity (x) {
   if (x <= 64) {

lib/precompiled/06-ecadd.js

@@ -1,6 +1,7 @@
 const utils = require('ethereumjs-util')
 const BN = utils.BN
 const error = require('../constants.js').ERROR
+const fees = require('ethereum-common')
 
 const bn128_module = require('rustbn.js')
 const ecAdd_precompile = bn128_module.cwrap('ec_add', 'string', ['string'])
@@ -10,8 +11,7 @@ module.exports = function (opts) {
   let data = opts.data
   let inputHexStr = data.toString('hex')
 
-  // Temporary, replace with finalized gas cost from EIP spec (via ethereum-common)
-  results.gasUsed = new BN(500)
+  results.gasUsed = new BN(fees.ecAddGas.v)
   try {
     let returnData = ecAdd_precompile(inputHexStr)
     results.return = Buffer.from(returnData, 'hex')

lib/precompiled/07-ecmul.js

@@ -1,5 +1,6 @@
 const utils = require('ethereumjs-util')
 const BN = utils.BN
+const fees = require('ethereum-common')
 
 const bn128_module = require('rustbn.js')
 const ecMul_precompile = bn128_module.cwrap('ec_mul', 'string', ['string'])
@@ -21,7 +22,6 @@ module.exports = function (opts) {
     results.exception = 0
   }
 
-  // Temporary, replace with finalized gas cost from EIP spec (via ethereum-common)
-  results.gasUsed = new BN(40000)
+  results.gasUsed = new BN(fees.ecMulGas.v)
   return results
 }

lib/precompiled/08-ecpairing.js

@@ -1,6 +1,7 @@
 const utils = require('ethereumjs-util')
 const BN = utils.BN
 const error = require('../constants.js').ERROR
+const fees = require('ethereum-common')
 
 const bn128_module = require('rustbn.js')
 const ecPairing_precompile = bn128_module.cwrap('ec_pairing', 'string', ['string'])
@@ -13,8 +14,8 @@ module.exports = function (opts) {
   let inputData = Buffer.from(inputHexStr, 'hex')
   let inputDataSize = Math.floor(inputData.length / 192)
 
-  // Temporary, replace with finalized gas cost from EIP spec (via ethereum-common)
-  const gascost = 100000 + (inputDataSize * 80000)
+
+  const gascost = fees.ecPairingGas.v + (inputDataSize * fees.ecPairingWordGas.v)
   results.gasUsed = new BN(gascost)
 
   if (opts.gasLimit.ltn(gascost)) {