vm: add dynamic opcode pricing by Turalchik · Pull Request #4087 · nspcc-dev/neo-go

Turalchik · 2025-11-18T14:29:00Z

After the introduction of the new pricing, the mainnet accepts blocks up to the block with the index 295097, because there are not enough funds to execute the transaction in block 295098:

wrong dump file or settings mismatch: failed to add block 295098: onPersist failed: VM has failed: at instruction 0 (SYSCALL): insufficient funds

Mainnet states match.

go run ./scripts/compare-states/compare-states.go http://127.0.0.1:10332 http://127.0.0.1:10334
at 0: 58a5157b7e99eeabf631291f1747ec8eb12ab89461cda888492b17a301de81e8 vs 58a5157b7e99eeabf631291f1747ec8eb12ab89461cda888492b17a301de81e8
at 295097: ed6df187f75e1f68225b412495856e5d45bb1377c35202eaa65c16cb4fe31f07 vs ed6df187f75e1f68225b412495856e5d45bb1377c35202eaa65c16cb4fe31f07

Mainnet gas consumed match.

go run ./scripts/compare-gasconsumed/compare-gasconsumed.go http://127.0.0.1:10332 http://127.0.0.1:10334 0 295097
compare-gasconsumed: all checks passed

Testnet gas consumed match.

go run ./scripts/compare-gasconsumed/compare-gasconsumed.go http://127.0.0.1:10332 http://127.0.0.1:20332 0 601084
compare-gasconsumed: all checks passed

Privnet with https://github.com/nspcc-dev/neo-bench states match.

go run ./scripts/compare-states/compare-states.go http://127.0.0.1:30335 http://127.0.0.1:30333 --ignore-height 
at 0: 64b81230de46a763f167b8b4b0d0ee3383e5b162d2d93cf66bf7d815c584a5c1 vs 64b81230de46a763f167b8b4b0d0ee3383e5b162d2d93cf66bf7d815c584a5c1
at 68: ca76fffbd5138e4d2ba198ab74b0d145525bbd6f60cf8502828cf341fd363ba6 vs ca76fffbd5138e4d2ba198ab74b0d145525bbd6f60cf8502828cf341fd363ba6

Privnet with https://github.com/nspcc-dev/neo-bench gas consumed match.

go run ./scripts/compare-gasconsumed/compare-gasconsumed.go http://127.0.0.1:30335 http://127.0.0.1:30333 0 68
compare-gasconsumed: all checks passed

Comparison statistics for the old model on the mainnet:

go run ./scripts/compare-gasconsumed/compare-gasconsumed.go -r http://127.0.0.1:10332 http://127.0.0.1:20334 0 295097
ratio analysis (A/B):
  transactions: 33085
  average: 1.290861
  min: 0.105444
  max: 77.982933
  stddev: 1.515816

Comparison statistics for the old model on the mainnet:

go run ./scripts/compare-gasconsumed/compare-gasconsumed.go -r http://127.0.0.1:10332 http://127.0.0.1:20332 0 601084
ratio analysis (A/B):
  transactions: 632506
  average: 1.010010
  min: 0.530678
  max: 109.903513
  stddev: 0.171589

Related issues with gas consumption consistency: #4288, #4291, #4294, #4295

codecov · 2025-11-27T19:19:23Z

Codecov Report

❌ Patch coverage is 76.54723% with 72 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.43%. Comparing base (48a0ae4) to head (886b761).
⚠️ Report is 16 commits behind head on master.

Files with missing lines	Patch %	Lines
pkg/core/fee/opcode.go	18.18%	72 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4087      +/-   ##
==========================================
- Coverage   83.56%   83.43%   -0.13%     
==========================================
  Files         359      359              
  Lines       44158    44425     +267     
==========================================
+ Hits        36901    37067     +166     
- Misses       5438     5541     +103     
+ Partials     1819     1817       -2

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AnnaShaleva

@Turalchik, conflicts.

The first part of review, will submit more later.

AnnaShaleva · 2026-01-15T09:28:57Z

Conflicts.

AnnaShaleva · 2026-04-08T12:56:54Z

+
+func OpcodeDynamic(base int64, op opcode.Opcode, args *vm.PriceArgs) int64 {
+	if dynamicCoefficients[op] == nil {
+		fmt.Println(op, args)


Shouldn't be here.

AnnaShaleva · 2026-04-08T12:58:52Z

+	if dynamicCoefficients[op] == nil {
+		fmt.Println(op, args)
+	}
+	return base * max(1, dynamicCoefficients[op](args)/factor)


Shouldn't be like that. Calculate the overall price of all opcodes in the script and then divide the resulting sum by the factor.

AnnaShaleva · 2026-04-08T13:03:24Z

+}
+
+func AppendGas(args *vm.PriceArgs) int64 {
+	return dotInts(appendW, []int64{int64(args.Refs), int64(args.NClonedItems), 1})


Additional slice allocation on every opcode doesn't bring us anything good. Remove dotInts, use direct multiplication.

AnnaShaleva · 2026-04-08T13:31:21Z

 		for range n {
 			key := v.estack.popNoRef()
 			val := v.estack.popNoRef().value
+			numComparisons += m.Len()


Is it m.Len() or the number of iterations over cycle? m.Len() may be different from the number of iterations in case if map has duplicated entries.

I do not know how we can find out the number of comparisons if Add cannot return it #4202 (comment).

It's just a question. OK, I think we're fine with m.Len() here.

AnnaShaleva · 2026-04-08T13:34:01Z

-			v.estack.PushItem(t.Value().([]stackitem.MapElement)[index].Value.Dup())
+			m := t.Value().([]stackitem.MapElement)
+			item = m[i].Value.Dup()


No need to declare m, useless variable.

AnnaShaleva · 2026-04-08T13:39:32Z

+		r := v.refs
+		var (
+			item = v.estack.Pop()
+			n    int
+		)


Move r under var declaration.

AnnaShaleva · 2026-04-08T13:40:37Z


-func (v *VM) cpValues(src iter.Seq[stackitem.Item], n int, isReferenced bool) []stackitem.Item {
-	arr := make([]stackitem.Item, 0, n)
+func (v *VM) cpValues(src iter.Seq[stackitem.Item], n int, isReferenced bool) ([]stackitem.Item, int) {


Doc for int return is needed.

AnnaShaleva · 2026-04-10T15:18:37Z

 	if scparser.IsSignatureContract(script) {
 		size += 67 + io.GetVarSize(script)
-		netFee += Opcode(base, opcode.PUSHDATA1, opcode.PUSHDATA1) + base*ECDSAVerifyPrice
+		netFee += Opcode(base, opcode.PUSHDATA1, opcode.PUSHDATA1)/factor + base*ECDSAVerifyPrice


Two problems here:

fee.Opcode() behaviour change

The behaviour of Opcode() shouldn't be changed because it's an exported API that may be used by some external users.

I see two possible solutions:

I

Divide the result of fee.Opcode by factor internally, inside fee.Opcode itself (it will return Datoshi then).

Use new OpcodeV0 function as VM's PriceGetter for pre-Gorgon (it will return Datoshi*factor, but with old coefficients).

Use new OpcodeV1 function as VM's PriceGetter for post-Gorgon (also will return `Datoshi*factor, but with new coefficients).

II

Add an extra factor argument to Opcode. Use pre-Gorgon coefficients if factor is 0 and use post-Gorgon coefficients otherwise.

@roman-khimov, do you have other suggestions? Which one do you prefer?

fee.Calculate() becomes Gorgon-dependent.

The behaviour of fee.Calculate (and other similar and dependent APIs) becomes Gorgon-dependent.

I can suggest introducing fee.CalculateV0 (using pre-Gorgon coefficients and returning Datoshi*factor) and fee.CalculateV1 (using post-Gorgon coefficients, returning Datoshi*factor). Dependent functions will have to switch between two implementations by themselves based on Gorgon. It's also important to keep the original behaviour of fee.Calculate unchanged.

@roman-khimov also need your opinion on that.

AnnaShaleva · 2026-04-10T15:19:25Z

+const factor = 1000
+
+// Opcode price weights used in dynamic fee formulas.
+// All values are multiplied by vm.OpcodePriceMultiplier.


Suggested change

// All values are multiplied by vm.OpcodePriceMultiplier.

// All values are multiplied by [vm.OpcodePriceMultiplier].

Use it for every link in doc.

AnnaShaleva · 2026-04-10T15:24:17Z

+)
+
+// OpcodeV1 returns opcode pricing used since Gorgon hardfork,
+// supporting dynamic (input-dependent) costs.


s/(input-dependent)/(parameter-dependent)

AnnaShaleva · 2026-04-10T15:31:23Z

+	}
+)
+
+// OpcodeV1 returns opcode pricing used since Gorgon hardfork,


returns opcode pricing

... in the unit of Datoshi*[vm.OpcodePriceMultiplier]

AnnaShaleva · 2026-04-10T15:38:33Z

 		opcode.PUSH4, // amount of args
 		opcode.PACK,  // pack args
-	)
+	) / vm.OpcodePriceMultiplier


It's OK for the old version of Opcode to divide by vm.OpcodePriceMultiplier in the middle of the script calculation. However, it won't be OK for OpcodeV1; the division should happen after the final price is known and the final value should be rounded up to cover non-integer remnant.

AnnaShaleva · 2026-04-10T15:39:34Z

-// Array fields are still copied by reference.
-func (i *Struct) Clone() (*Struct, error) {
+// Clone returns a Struct with all Struct fields copied by the value
+// and number of cloned items. Array fields are still copied by reference.


s/items/fields

... including the struct itself.

AnnaShaleva · 2026-04-10T15:41:01Z


+// PriceArgs contains opcode-specific parameters used to calculate dynamic price.
+type PriceArgs struct {
+	// Typ specifies type of stack item involved in opcode.


s/stack item/[stackitem.Item]

s/involved in opcode/which in most of the cases serves as an operand of the given opcode.

AnnaShaleva · 2026-04-10T15:45:47Z

 }

+// PriceArgs contains opcode-specific parameters used to calculate dynamic price.
+type PriceArgs struct {


s/PriceArgs/OpcodePriceArgs or something like that?

Just because vm.PriceArgs is too wide definition if referred from an external user package.

AnnaShaleva · 2026-04-10T15:56:11Z

+	// Size is size of compound type, buffer or bytearray length,
+	// number slots or stack elements.
+	Size int


Suggested change

// Size is size of compound type, buffer or bytearray length,

// number slots or stack elements.

Size int

// Size denotes one of the following:

// - the number of elements in the compound type (i.e. the length of Array or Struct, the number of key-value pairs in Map);

// - the length of Buffer or ByteArray;

// - the number of VM slot cells or stack elements involved into opcode handling.

Size int

@Turalchik we need to be specific and precise. Imagine external users using this parameter to calculate something.

And may be it's worth to rename Size to Length?

AnnaShaleva · 2026-04-13T11:18:21Z

+	return dst
+}
+
+// OpcodeDynamic returns dynamic opcode prices used since Gorgon hardfork.


Suggested change

// OpcodeDynamic returns dynamic opcode prices used since Gorgon hardfork.

// opcodeDynamic returns dynamic opcode prices used since Gorgon hardfork.

AnnaShaleva · 2026-04-29T10:57:52Z

+	var priceArgs *OpcodePriceArgs
+	defer func(canGetPrice bool) {
+		if canGetPrice {
+			v.gasConsumed += v.getPrice(op, parameter, priceArgs)


For cases when panic occurs in the middle of opcode handling, priceArgs argument is not set yet. It means all parameters are set to 0, so the result will be equal to the free term. Is it expected behaviour?Related to https://github.com/neo-project/neo-vm/pull/571/changes#r3160408408.

Close #4043. Signed-off-by: Tural Devrishev <tural@nspcc.ru>

Turalchik requested review from AnnaShaleva and roman-khimov as code owners November 18, 2025 14:29

Turalchik marked this pull request as draft November 18, 2025 14:29

Turalchik force-pushed the dynamic-opcode-pricing branch from b84940d to bf06cda Compare November 27, 2025 19:13

Turalchik force-pushed the dynamic-opcode-pricing branch 22 times, most recently from bb928b3 to 43b4467 Compare December 4, 2025 10:30

Turalchik force-pushed the dynamic-opcode-pricing branch from 43b4467 to 995606b Compare December 5, 2025 17:24

Turalchik force-pushed the dynamic-opcode-pricing branch 2 times, most recently from 174df2d to 0315022 Compare December 16, 2025 16:11

Turalchik force-pushed the dynamic-opcode-pricing branch 10 times, most recently from 0de3721 to 5196698 Compare December 22, 2025 07:50

AnnaShaleva reviewed Dec 23, 2025

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AnnaShaleva reviewed Jan 15, 2026

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Turalchik mentioned this pull request Jan 16, 2026

Dynamic opcode pricing #4043

Open

AnnaShaleva reviewed Apr 7, 2026

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Turalchik mentioned this pull request Apr 8, 2026

vm: add models for dynamic opcode prices #4218

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AnnaShaleva reviewed Apr 10, 2026

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AnnaShaleva reviewed Apr 29, 2026

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This was referenced May 29, 2026

scripts: add script for ApplicationLogs comparison #4287

Merged

GasConsumed mainnet diff at 105 #4288

Open

GasConsumed mainnet diff at 5107 #4291

Closed

GasConsumed mainnet diff at 10678 #4294

Closed

GasConsumed testnet diff at 399458 #4295

Closed

vm: add dynamic opcode pricing

886b761

Close #4043. Signed-off-by: Tural Devrishev <tural@nspcc.ru>

AnnaShaleva mentioned this pull request Jun 11, 2026

vm: properly manage gasConsumed overflow #4306

Merged

	// All values are multiplied by vm.OpcodePriceMultiplier.
	// All values are multiplied by [vm.OpcodePriceMultiplier].

	// OpcodeDynamic returns dynamic opcode prices used since Gorgon hardfork.
	// opcodeDynamic returns dynamic opcode prices used since Gorgon hardfork.

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AnnaShaleva commented Jan 15, 2026

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fee.Opcode() behaviour change

I

II

fee.Calculate() becomes Gorgon-dependent.

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Turalchik commented Nov 18, 2025 •

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codecov Bot commented Nov 27, 2025 •

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`fee.Opcode()` behaviour change

`fee.Calculate()` becomes Gorgon-dependent.