NTT
NTT Example​
package main
import (
"github.com/ingonyama-zk/icicle/v3/wrappers/golang/core"
"github.com/ingonyama-zk/icicle/v3/wrappers/golang/curves/bn254"
"github.com/ingonyama-zk/icicle/v3/wrappers/golang/curves/bn254/ntt"
"github.com/ingonyama-zk/icicle/v3/wrappers/golang/runtime"
"github.com/consensys/gnark-crypto/ecc/bn254/fr/fft"
)
func init() {
// Load backend using env path
runtime.LoadBackendFromEnvOrDefault()
// Set Cuda device to perform
device := runtime.CreateDevice("CUDA", 0)
runtime.SetDevice(&device)
cfg := core.GetDefaultNTTInitDomainConfig()
initDomain(18, cfg)
}
func initDomain(largestTestSize int, cfg core.NTTInitDomainConfig) runtime.EIcicleError {
rouMont, _ := fft.Generator(uint64(1 << largestTestSize))
rou := rouMont.Bits()
rouIcicle := bn254.ScalarField{}
limbs := core.ConvertUint64ArrToUint32Arr(rou[:])
rouIcicle.FromLimbs(limbs)
e := ntt.InitDomain(rouIcicle, cfg)
return e
}
func main() {
// Obtain the default NTT configuration with a predefined coset generator.
cfg := ntt.GetDefaultNttConfig()
// Define the size of the input scalars.
size := 1 << 18
// Generate scalars for the NTT operation.
scalars := bn254.GenerateScalars(size)
// Set the direction of the NTT (forward or inverse).
dir := core.KForward
// Allocate memory for the results of the NTT operation.
results := make(core.HostSlice[bn254.ScalarField], size)
// Perform the NTT operation.
err := ntt.Ntt(scalars, dir, &cfg, results)
if err != runtime.Success {
panic("NTT operation failed")
}
ntt.ReleaseDomain()
}
NTT Method​
func Ntt[T any](scalars core.HostOrDeviceSlice, dir core.NTTDir, cfg *core.NTTConfig[T], results core.HostOrDeviceSlice) runtime.EIcicleError
Parameters​
scalars
: A slice containing the input scalars for the transform. It can reside either in host memory or device memory.dir
: The direction of the NTT operation (KForward
orKInverse
).cfg
: A pointer to anNTTConfig
object, containing configuration options for the NTT operation.results
: A slice where the results of the NTT operation will be stored. This slice can be in host or device memory.
Return Value​
EIcicleError
: Aruntime.EIcicleError
value, which will beruntime.Success
if the operation was successful, or an error if something went wrong.
NTT Configuration (NTTConfig)​
The NTTConfig
structure holds configuration parameters for the NTT operation, allowing customization of its behavior to optimize performance based on the specifics of your protocol.
type NTTConfig[T any] struct {
StreamHandle runtime.Stream
CosetGen T
BatchSize int32
ColumnsBatch bool
Ordering Ordering
areInputsOnDevice bool
areOutputsOnDevice bool
IsAsync bool
Ext config_extension.ConfigExtensionHandler
}
Fields​
StreamHandle
: Specifies the stream (queue) to use for async execution.CosetGen
: Coset generator. Used to perform coset (i)NTTs.BatchSize
: The number of NTTs to compute in one operation, defaulting to 1.ColumnsBatch
: If true the function will compute the NTTs over the columns of the input matrix and not over the rows.Ordering
: Ordering of inputs and outputs (KNN
,KNR
,KRN
,KRR
), affecting how data is arranged.areInputsOnDevice
: Indicates if input scalars are located on the device.areOutputsOnDevice
: Indicates if results are stored on the device.IsAsync
: Controls whether the NTT operation runs asynchronously.Ext
: Extended configuration for backend.
Default Configuration​
Use GetDefaultNTTConfig
to obtain a default configuration, customizable as needed.
func GetDefaultNTTConfig[T any](cosetGen T) NTTConfig[T]
Initializing the NTT Domain​
Before performing NTT operations, it's necessary to initialize the NTT domain; it only needs to be called once per GPU since the twiddles are cached.
func InitDomain(primitiveRoot bn254.ScalarField, cfg core.NTTInitDomainConfig) runtime.EIcicleError
This function initializes the domain with a given primitive root, optionally using fast twiddle factors to optimize the computation.
Releasing the domain​
The ReleaseDomain
function is responsible for releasing the resources associated with a specific domain in the CUDA device context.
func ReleaseDomain() runtime.EIcicleError
Return Value​
EIcicleError
: Aruntime.EIcicleError
value, which will beruntime.Success
if the operation was successful, or an error if something went wrong.